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If you are not located in the United States, you -will have to check the laws of the country where you are located before -using this eBook. - -Title: Researches Chemical and Philosophical - Chiefly concerning nitrous oxide or dephlogisticated nitrous air - and its respiration - -Author: Humphry Davy - -Release Date: December 16, 2021 [eBook #66955] - -Language: English - -Character set encoding: UTF-8 - -Produced by: Tim Lindell and the Online Distributed Proofreading Team at - https://www.pgdp.net (This file was produced from images - generously made available by The Internet Archive) - -*** START OF THE PROJECT GUTENBERG EBOOK RESEARCHES CHEMICAL AND -PHILOSOPHICAL *** - - - - -Transcriber’s Notes: - - Underscores “_” before and after a word or phrase indicate _italics_ - in the original text. - Small capitals have been converted to SOLID capitals. - Illustrations have been moved so they do not break up paragraphs. - Antiquated spellings have been preserved. - Typographical and punctuation errors have been silently corrected. - The text usually uses a comma to designate a decimal point, although a - period is used in some instances. - The changes mentioned in the ERRATA have been applied to the text. - - - - - RESEARCHES, - CHEMICAL AND PHILOSOPHICAL; - CHIEFLY CONCERNING - NITROUS OXIDE, - - OR - DEPHLOGISTICATED NITROUS AIR, - AND ITS - RESPIRATION. - - By HUMPHRY DAVY, - - SUPERINTENDENT OF THE MEDICAL PNEUMATIC - INSTITUTION. - - LONDON: - - PRINTED FOR J. JOHNSON, ST. PAUL’S CHURCH-YARD, - BY BIGGS AND COTTLE, BRISTOL, - 1800. - - - - -CONTENTS. - - - INTRODUCTION, xi. - - RESEARCH I. - _Into the analysis of_ NITRIC ACID _and_ NITROUS GAS, - _and the production of_ NITROUS OXIDE. - - DIVISION I. - EXPERIMENTS _and_ OBSERVATIONS _on the composition - of_ NITRIC ACID, _and on its combinations with_ - WATER _and_ NITROUS GAS. - - 1. Preliminaries 1 - 2. Production of aëriform Nitrous Acid 3 - 3. Specific gravity of Gases 6 - 4. Experiment on the formation of Nitrous Acid 11 - 5. Conclusions 17 - 6. Experiments on the combination of Nitrous Gas - with Nitric Acid 17 - 7. Additional Experiments 23 - 8. Conclusions 29 - 9. Mr. THOMSON’S Theory of the difference - between Nitric and Nitrous Acid 30 - 10. Composition of the different Nitrous Acids 36 - 11. Combination of Nitric Acid with Water 38 - 12. Of Nitrous Vapor 42 - 13. Comparison of the results with those of - Cavendish and Lavoisier 43 - - DIVISION II. - EXPERIMENTS _and_ OBSERVATIONS _on the composition - of_ AMMONIAC _and on its combinations with_ WATER - _and_ NITRIC ACID. - - 1. Analysis of Ammoniac 56 - 2. Specific gravity of Ammoniac 62 - 3. Of the quantities of true Ammoniac in - Ammoniacal Solutions 65 - 4. Composition of Nitrate of Ammoniac 71 - 5. Decomposition of Carbonate of Ammoniac, - by Nitrous Acid 75 - 6. Decomposition of Sulphate of Ammoniac by Nitre 77 - 7. Non-existence of Ammoniacal Nitrites 79 - 8. Sources of error in Analysis 80 - 9. Loss in Solutions of Nitrate of Ammoniac - during evaporation 83 - - DIVISION III. - DECOMPOSITION _of_ NITRATE _of_ AMMONIAC—_Preparation - of_ RESPIRABLE NITROUS OXIDE. - - 1. Of the heat required for the decomposition of - Nitrate of Ammoniac 84 - 2. Decomposition of Nitrate of Ammoniac—Production - of respirable Nitrous Oxide—its properties 86 - 3. Of the Gas remaining after the absorption of - Nitrous Oxide by Water 89 - 4. Specific Gravity of Nitrous Oxide 94 - 5. Analysis of Nitrous Oxide 95 - 6. Minute examination of the decomposition - of Nitrate of Ammoniac 101 - 7. Of the heat produced during the decomposition - of Nitrate of Ammoniac 108 - 8. Decomposition of Nitrate of Ammoniac at - high temperatures 109 - 9. Speculations on the decompositions of Nitrate - of Ammoniac 113 - 10. Of the preparation of Nitrous Oxide for - experiments on respiration 117 - - DIVISION IV. - EXPERIMENTS _and_ OBSERVATIONS _on the composition of_ - NITROUS GAS, _and on its absorption by different - bodies_. - - 1. Preliminaries 122 - 2. Analysis of Nitrous Gas by Charcoal 126 - 3. Analysis of Nitrous Gas by Pyrophorus 132 - 4. Additional observations on the composition of - Nitrous Gas 134 - 5. Absorption of Nitrous Gas by Water 140 - 6. Absorption of Nitrous Gas by Water of - different kinds 147 - 7. Absorption of Nitrous Gas by solution of - pale green Sulphate of Iron 152 - 8. Absorption of Nitrous Gas by solution of - green muriate of Iron 179 - 9. By Solution of Nitrate of Iron 187 - 10. By other metallic Solutions 189 - 11. Action of sulphurated Hydrogene on solution - of green sulphate of iron impregnated with - Nitrous Gas 191 - 12. Additional Observations 193 - - DIVISION V. - EXPERIMENTS _and_ OBSERVATIONS _on the production of_ - NITROUS OXIDE _from_ NITROUS GAS _and_ NITRIC ACID - _in different modes_. - - 1. Preliminaries 197 - 2. Conversion of Nitrous Gas into Nitrous Oxide - by alkaline sulphites 199 - 3. By Muriate of Tin 202 - 4. By Sulphurated Hydrogene 203 - 5. Decomposition of Nitrous Gas by Nascent - Hydrogene 206 - 6. Miscellaneous Observations 209 - 7. Recapitulation 211 - 8. Production of Nitrous Oxide from Metallic - Solutions 213 - 9. Additional Observations relating to the - production of Nitrous Oxide 219 - 10. Decomposition of Aqua regia by platina, - and evolution of a gas analogous to oxygenated - muriatic acid, and nitrogene 222 - 11. Action of the electric spark on a mixture - of Nitrogene and Nitrous gas 229 - 12. General remarks on the production - of Nitrous Oxide 231 - - RESEARCH II. - _Into the combinations of_ NITROUS OXIDE, - _and its decomposition_. - - DIVISION I. - EXPERIMENTS _and_ OBSERVATIONS _on the combinations - of_ NITROUS OXIDE. - - 1. Combination of Water with Nitrous Oxide 235 - 2. —— of Nitrous Oxide with fluid inflammable - bodies 240 - 3. Action of fluid Acids on Nitrous Oxide 244 - 4. —— of Saline Solutions 245 - 5. —— of Gases 248 - 6. Action of aëriform Nitrous Oxide on the - alkalies—History of the discovery of the - combinations of Nitrous Oxide, with the - alkalies 254 - 7. Combination of Nitrous Oxide with Potash 262 - 8. Combination of Nitrous Oxide with Soda 268 - 9. —— —— —— with Ammoniac 269 - 10. Probability of forming compounds of - Nitrous Oxide and the alkaline earths 273 - 11. Additional Observations 274 - 12. The properties of Nitrous oxide resemble - those of Acids 276 - - DIVISION II. - _Decomposition of_ NITROUS OXIDE _by combustible Bodies_. - - 1. Preliminaries 278 - 2. Conversion of Nitrous Oxide into Nitrous Acid - and a gas analogous to Atmospheric Air - by ignition 279 - 3. Decomposition of Nitrous Oxide by Hydrogene 286 - 4. —— —— —— by Phosphorus 293 - 5. —— —— by Phosphorated Hydrogene 300 - 6. —— —— by Sulphur 303 - 7. —— —— by Sulphurated Hydrogene 306 - 8. —— —— by Charcoal 311 - 9. —— —— by Hydrocarbonate 313 - 10. Combustion of Iron in Nitrous Oxide 316 - 11. —— of Pyrophorus 318 - 12. —— of the Taper 319 - 13. —— of different Compound Bodies 321 - 14. General Conclusions relating to the - decomposition of Nitrous Oxide, and - to its analysis 322 - 15. Observations on the combinations of Oxygene - and Nitrogene 325 - - RESEARCH III. - _Relating to the_ RESPIRATION _of_ NITROUS OXIDE - _and_ OTHER GASES. - - DIVISION I. - EXPERIMENTS _and_ OBSERVATIONS _on the effects produced - upon Animals by the respiration of_ NITROUS OXIDE. - - 1. Preliminaries 333 - 2. On the respiration of Nitrous Oxide by - warm-blooded Animals 336 - 3. Effects of the respiration of Nitrous Oxide - upon Animals, as compared with those produced - by their immersion in Hydrogene and Water 343 - 4. Of the changes effected in the organisation of - warm-blooded Animals, by the respiration of - Nitrous Oxide 347 - 5. Of the respiration of mixtures of Nitrous Oxide - and other Gases, by warm-blooded Animals 358 - 6. Recapitulation of facts relating to the - respiration of Nitrous Oxide, by warm-blooded - Animals 360 - 7. Of the respiration of Nitrous Oxide, - by amphibious Animals 362 - 8. Effects of Solution of Nitrous Oxide on Fishes 366 - 9. Effects of Nitrous Oxide on Insects 370 - - DIVISION II. - _Of the changes effected in_ NITROUS OXIDE - _and other Gases, by the Respiration of Animals_. - - 1. Preliminaries 373 - 2. Absorption of Nitrous Oxide by Venous Blood 374 - 3. Of the changes effected in Nitrous Oxide - by Respiration 388 - 4. Respiration of Hydrogene 400 - 5. Additional Observations and Experiments on the - Respiration of Nitrous Oxide 411 - 6. Of the Respiration of Atmospheric Air 429 - 7. Respiration of Oxygene 439 - 8. Observations on the changes effected in the - blood by Atmospheric Air and Oxygene 445 - 9. Observations on the Respiration of Nitrous Oxide 449 - - RESEARCH IV. - _Relating to the_ EFFECTS _produced by the_ - RESPIRATION _of_ NITROUS OXIDE - _upon different_ INDIVIDUALS. - - DIVISION I. - HISTORY _of the Discovery_.—EFFECTS _produced - by the Respiration of different_ GASES. - - 1. Respirability of Nitrous Oxide 456 - 2. Effects of Nitrous Oxide 458 - 3. General Effects of Nitrous Oxide on the Health 464 - 4. Respiration of Hydrogene 466 - 5. —— of Nitrogene 467 - 6. Effects of Hydrocarbonate 468 - 7. —— of Carbonic Acid 472 - 8. —— of Oxygene 473 - 9. —— of Nitrous Gas 475 - 10. Most extensive action of Nitrous Oxide - produces no debility 485 - - DIVISION II. - DETAILS _of the Effects produced by the Respiration - of_ NITROUS OXIDE _upon different Individuals, - furnished by Themselves_. - - 1. Detail of Mr. J. W. Tobin 497 - 2. —— of Mr. W. Clayfield 502 - 3. Letter from Dr. Kinglake 503 - 4. Detail of Mr. Southey 507 - 5. Letter from Dr. Roget 509 - 6. Letter from Mr. James Thomson 512 - 7. Detail of Mr. Coleridge 516 - 8. —— of Mr. Wedgwood 518 - 9. —— of Mr. G. Burnet 520 - 10. —— of Mr. T. Pople 521 - 11. —— of Mr. Hammick 522 - 12. —— of Dr. Blake 524 - 13. —— of Mr. Wanfey 525 - 14. —— of Mr. Rickman 526 - 15. —— of Mr. Lovell Edgworth 527 - 16. —— of Mr. G. Bedford 528 - 17. —— of Miss Ryland 530 - 18. Letter from Mr. M. M. Coates 530 - - DIVISION III. - _Abstracts from additional Details—Observations on - the effects of_ NITROUS OXIDE, - _by_ Dr. BEDDOES—_Conclusion_. - - 1. Abstracts from additional details 533 - 2. Of the effects of Nitrous Oxide on - delicate females 537 - 3. Observations on the effects of Nitrous Oxide - by Dr. BEDDOES 541 - 4. Conclusion 548 - - APPENDIX. - No. I. Of the effects of Nitrous Oxide - on Vegetables 561 - No. II. Table of the Weight and Composition - of the combinations of Nitrogene 566 - No. III. Additional Observations 567 - No. IV. Description of a Mercurial Airholder, - and Breathing Machine, - by Mr. W. CLAYFIELD. 573 - No. V. Proposals for the Preservation of - Accidental Observations in Medicine. - By Dr. BEDDOES. 577 - - - - -INTRODUCTION. - - -In consequence of the discovery of the respirability and extraordinary -effects of nitrous oxide, or the dephlogisticated nitrous gas of Dr. -Priestley, made in April 1799, in a manner to be particularly described -hereafter,[1] I was induced to carry on the following investigation -concerning its composition, properties, combinations, and mode of -operation on living beings. - -[1] A short account of this discovery has been given in Dr. Beddoes’s -Notice of some Observations made at the Pneumatic Institution, and in -Mr. Nicholson’s Phil. Journal for May and December 1799. - -In the course of this investigation, I have met with many difficulties; -some arising from the novel and obscure nature of the subject, and -others from a want of coincidence in the observations of different -experimentalists on the properties and mode of production of the gas. -By extending my researches to the different substances connected -with nitrous oxide; nitrous acid, nitrous gas and ammoniac; and by -multiplying the comparisons of facts, I have succeeded in removing the -greater number of those difficulties, and have been enabled to give a -tolerably clear history of the combinations of oxygene and nitrogene. - -By employing both analysis and synthesis whenever these methods were -equally applicable, and comparing experiments made under different -circumstances, I have endeavoured to guard against sources of error; -but I cannot flatter myself that I have altogether avoided them. The -physical sciences are almost wholly dependant on the minute observation -and comparison of properties of things not immediately obvious to the -senses; and from the difficulty of discovering every possible mode of -examination, and from the modification of perceptions by the state -of feeling, it appears nearly impossible that all the relations of -a series of phænomena can be discovered by a single investigation, -particularly when these relations are complicated, and many of the -agents unknown. Fortunately for the active and progressive nature -of the human mind, even experimental research is only a method of -approximation to truth. - -In the arrangement of facts, I have been guided as much as possible by -obvious and simple analogies only. Hence I have seldom entered into -theoretical discussions, particularly concerning light, heat, and other -agents, which are known only by isolated effects. - -Early experience has taught me the folly of hasty generalisation. We -are ignorant of the laws of corpuscular motion; and an immense mass of -minute observations concerning the more complicated chemical changes -must be collected, probably before we shall be able to ascertain even -whether we are capable of discovering them. Chemistry in its present -state, is simply a partial history of phænomena, consisting of many -series more or less extensive of accurately connected facts. - -With the most important of these series, the arrangement of the -combinations of oxygene or the antiphlogistic theory discovered by -Lavoisier, the chemical details in this work are capable of being -connected. - -In the present state of science, it will be unnecessary to enter into -discussions concerning the importance of investigations relating to -the properties of physiological agents, and the changes effected in -them during their operation. By means of such investigations, we arrive -nearer towards that point from which we shall be able to view what is -within the reach of discovery, and what must for ever remain unknown to -us, in the phænomena of organic life. They are of immediate utility, by -enabling us to extend our analogies so as to investigate the properties -of untried substances, with greater accuracy and probability of -success. - -The first Research in this work chiefly relates to the production -of nitrous oxide and the analysis of nitrous gas and nitrous acid. -In this there is little that can be properly called mine; and if by -repeating the experiments of other chemists, I have sometimes been able -to make more minute observations concerning phænomena, and to draw -different conclusions, it is wholly owing to the use I have made of -the instruments of investigation discovered by the illustrious fathers -of chemical philosophy,[2] and so successfully applied by them to the -discovery of truth. - -[2] Cavendish, Priestley, Black, Lavoisier, Scheele, Kirwan, Guyton, -Berthollet, &c. - -In the second Research the combinations and composition of nitrous -oxide are investigated, and an account given of its decomposition by -most of the combustible bodies. - -The third Research contains observations on the action of nitrous -oxide upon animals, and an investigation of the changes effected in it -by respiration. - -In the fourth Research the history of the respirability and -extraordinary effects of nitrous oxide is given, with details of -experiments on its powers made by different individuals. - -I cannot close this introduction, without acknowledging my obligations -to Dr. Beddoes. In the conception of many of the following experiments, -I have been aided by his conversation and advice. They were executed -in an Institution which owes its existence to his benevolent and -philosophic exertions. - - _Dowry-Square, Hotwells, Bristol._ - _June 25th, 1800._ - - - - - RESEARCH I. - - CONCERNING THE ANALYSIS OF - NITRIC ACID AND NITROUS GAS - AND THE PRODUCTION OF - NITROUS OXIDE. - -[Illustration: _Pl. I. MERCURIAL AIRHOLDER and BREATHING MACHINE_. - -_Lowry sculpᵗ._] - -RESEARCH I. - -INTO THE PRODUCTION AND ANALYSIS OF NITROUS OXIDE, AND THE AËRIFORM -FLUIDS RELATED TO IT. - - -DIVISION I. - - _EXPERIMENTS and OBSERVATIONS on the composition - of_ NITRIC ACID, _and on its combinations - with_ WATER _and_ NITROUS GAS. - -I. Though since the commencement of Pneumatic Chemistry, no substance -has been more the subject of experiment than Nitrous Acid; yet still -the greatest uncertainty exists with regard to the quantities of the -principles entering into its composition. - -In comparing the experiments of the illustrious Cavendish on the -synthesis of nitrous acid, with those of Lavoisier on the decomposition -of nitre by charcoal, we find a much greater difference in the results -than can be accounted for by supposing the acid formed, and that -decomposed, of different degrees of oxygenation. - -In the most accurate experiment of Cavendish, when the nitrous acid -appeared to be in a state of deoxygenation, 1 of nitrogene combined -with about 2,346 of oxygene.[3] In an earlier experiment, when the -acid was probably fully oxygenated, the nitrogene employed was to the -oxygene nearly as 1 to 2,92.[4] - -Lavoisier, from his experiments on the decomposition of nitre, and -combination of nitrous gas and oxygene, concludes, that the perfectly -oxygenated, or what he calls nitric acid, is composed of nearly 1 -nitrogene, with 3,9 of oxygene; and the acid in the last state of -deoxygenation, or nitrous acid, of about 3 oxygene with 1 nitrogene.[5] - -[3] Phil. Trans. v. 78, p. 270. - -[4] Phil. Trans. v. 75 p. 381. - -[5] Elem. Kerr’s Trans. page 76, and 216, and Mem. des Sav. Etrang. -tom. 7, page 629. - -Great as the difference is between the estimations of these -philosophers, we find differences still greater in the accounts of the -quantities of nitrous gas necessary to saturate a given quantity of -oxygene, as laid down by very accurate experimentalists. On the one -hand, Priestley found 1 of oxygene condensed by 2 of nitrous gas, and -Lavoisier by 1⅞. On the other, Ingenhouz, Scherer, and De la Metherie, -state the quantity necessary to be from 3 to 5.[6] Humbolt, who has -lately investigated Eudiometry with great ingenuity, considers the mean -quantity of nitrous gas necessary to saturate 1 of oxygene, as about -2,55.[7] - -[6] Ingenhouz sur les Vegetaux, pag. 205. De la Metherie. Essai sur -differens Airs, pag. 252. - -[7] Annales de Chimie, tome 28, p. 168. - -II. To reconcile these different results is impossible, and the -immediate connection of the subject with the production of nitrous -oxide, as well as its general importance, obliged me to search for -means of accurately determining the composition of nitrous acid in its -different degrees of oxygenation. - -The first desideratum was to ascertain the nature and composition of a -fluid acid, which by being deprived of, or combined with nitrous gas, -might become a standard of comparison for all other acids. - -To obtain this acid I should have preferred the immediate combination -of oxygene and nitrogene over water by the electric spark, had it -been possible to obtain in this way by a common apparatus sufficient -for extensive examination; but on carefully perusing the laborious -experiments of Cavendish, I gave up all thoughts of attempting it. - -My first experiments were made on the decomposition of nitre, -formed from a known quantity of pale nitrous acid of known specific -gravity, by phosphorus, tin, and charcoal: but in those processes, -unascertainable quantities of nitrous acid, with excess of nitrous -gas, always escaped undecompounded, and from the non-coincidence -of results, where different quantities of combustible substances -were employed, I had reasons for believing that water was generally -decomposed. - -Before these experiments were attempted, I had analized nitrous gas -and nitrous oxide, in a manner to be particularly described hereafter; -so that a knowledge of the quantities of nitrous gas and oxygene -entering into the composition of any acid, enabled me to determine the -proportions of nitrogene and oxygene it contained. In consequence of -which I attempted to combine together oxygene and nitrous gas, in such -a manner as to absorb the nitrous acid formed by water, in an apparatus -by which the quantities of the gases employed, and the increase of -weight of the water, might be ascertained; but this process likewise -failed. It was impossible to procure the gases perfectly free from -nitrogene, and during their combination, this nitrogene made to pass -into a pneumatic apparatus communicating with a vessel containing the -water carried over with it, much nitrous acid vapor, of different -composition from the acid absorbed. - -After many unsuccessful trials, Dr. Priestley’s experiments on nitrous -vapor[8] induced me to suppose that oxygene and nitrous gas, made to -combine out of the contact of bodies having affinity for oxygene, would -remain permanently aëriform, and on throwing them separately into an -exhausted glass balloon, I found that this was actually the case; -increase of temperature was produced, and orange colored nitrous acid -gas formed, which after remaining for many days in the globe, at a -temperature below 56°, did not in the slightest degree condense. - -[8] Experiments and Observations, Vol. iii. last edition, page 105, &c. - -This fact afforded me the means not only of forming a standard acid, -but likewise of ascertaining the specific gravity of nitrous acid in -its aëriform state. - -III. Previous to the experiment, for the purpose of correcting -incidental errors, I was induced to ascertain the specific gravity of -the gases employed, particularly as I was unacquainted with any process -by which the weight of nitrous gas had been accurately determined. Mr. -Kirwan’s estimation, which is generally adopted, being founded upon -the comparison of the loss of weight of a solution of copper in dilute -nitrous acid, with the quantity of gas produced.[9] - -The instruments that I made use of for containing and measuring my -gases, were two mercurial airholders graduated to the cubic inch of -Everard, and furnished with stop-cocks.[10] - -[9] When copper is dissolved in dilute nitrous acid, certain quantities -of nitrogene are generally produced, likewise the nitrous gas carries -off in solution some nitrous acid. - -[10] This airholder, considered as a pneumatic instrument, is of -greater importance, and capable of a more extensive application than -any other. It was invented by Mr. W. CLAYFIELD, and in its form is -analogous to Mr. WATT’S hydraulic bellows, consisting of a glass bell -playing under the pressure of the atmosphere, in a space between two -cylinders filled with mercury. A particular account of it will be given -in the appendix. - -They were weighed in a glass globe, of the capacity of 108 cubic -inches, which with the small glass stop-cock affixed to it, was equal, -when filled with atmospheric air, to 1755 grains. The balance that I -employed, when loaded with a pound, turned with less than one eighth of -a grain. - -Into a mercurial airholder, of the capacity of 200 cubic inches, 160 -cubic inches of nitrous gas were thrown from a solution of mercury in -nitrous acid. - -70 measures of this were agitated for some minutes in a solution of -sulphate of iron,[11] till the diminution was complete. The nitrogene -remaining hardly filled a measure; and if we suppose with Humbolt[12] -that a very small portion of it was absorbed with the nitrous gas, the -whole quantity it contained may be estimated at 0,0142, or ¹/₇₀. - -[11] This absorption will be hereafter particularly treated of. - -[12] Annales de Chimie. Tome xviii. page 139. - -75 cubic inches received from the airholder into an exhausted balloon, -increased it in weight 25,5 grains; thermometer being 56°, and -barometer 30,9. And allowing for the small quantity of nitrogene in the -gas, 100 cubic inches of it will weigh 34.3 grains. - -One hundred and thirty cubic inches of oxygene were procured from oxide -of manganese and sulphuric acid, by heat, and received in another -mercurial airholder. - -10 measures of it, mingled with 26 of the nitrous gas, gave, after -the residuum was exposed to solution of sulphate of iron, rather more -than one measure. Hence we may conclude that it contained about 0,1 -nitrogene. - -60 cubic inches of it weighed 20,75 grains; and accounting for the -nitrogene contained in these, 100 grains of pure oxygene will weigh -35,09 grains. - -Atmospherical air was decomposed by nitrous gas in excess; and the -residuum washed with solution of sulphate of iron till the Nitrogene -remained pure; 87 cubic inches of it weighed 26,5 grains, thermometer -being 48°, barometer 30,1; 100 will consequently weigh 30,45. - -90 cubic inches of the air of the laboratory not deprived of its -carbonic acid, weighed 28,75 grains; thermometer 53, barometer 30: 100 -cubic inches will consequently weigh 31,9.[13] 16 measures of this air, -with 16 nitrous gas, of known composition, diminished to 19. Hence it -contained about,26 oxygene.[14] - -In comparing my results with those of Lavoisier and Kirwan, the -estimation of the weights of nitrogene and oxygene is very little -different, the corrections for temperature and pressure being made, -from that of those celebrated philosophers. The first makes oxygene to -weigh[15] 34,21, and nitrogene 30,064 per cent; and the last, oxygene -34,[16] and nitrogene 30,5. - -[13] A table of the specific gravities of these gases, and other gases, -hereafter to be mentioned, reduced to a barometrical and thermometrical -standard, will be given in the appendix. - -[14] 40 measures, exposed to solution of potash, gave an absorption of -not quite a quarter of a measure: hence it contained an inconsiderable -quantity of carbonic acid. - -[15] Traité Elementaire. - -[16] Essai sur le phlogistique, page 30. - -The specific gravity of nitrous gas, according to Kirwan, is to that of -common air as 1194 to 1000. Hence it should weigh about 37 grains per -cent. This difference from my estimation is not nearly so great as I -expected to have found it.[17] - -IV.[18] The thermometer in the laboratory standing at 55°, and the -barometer at 30,1, I now proceeded to my experiment. The oxygene that -I employed was of the same composition as that which I had previously -weighed. The nitrous gas contained,0166 nitrogene. - -For the purpose of combining the gases, a glass balloon was procured, -of the capacity of 148 cubic inches, with a glass stop-cock adapted to -it, having its upper orifice tubulated and graduated for the purpose of -containing and measuring a fluid. The whole weight of this globe and -its appendages, when filled with common air, was 2066,5 grains. - -[17] The diminution of the specific gravity of the gas from the -quantity of nitrogene evolved in his experiment, probably destroyed, in -some measure, the source of error from the nitrous acid carried over. - -[18] Experiment I. - -It was partially exhausted by the air-pump, and lost in weight just -32 grains. From whence we may conclude that about 15 grains of air -remained in it. - -In this state of exhaustion it was immediately cemented to the -stop-cock of the mercurial airholder, and the communication being made -with great caution, 82 cubic inches of nitrous gas rushed into the -globe, on the outside of which a slight increase of temperature was -perceived, while the gases on the inside appeared of a deep orange. - -Before the common temperature was restored, the communication was -stopped, and the globe removed. The increase of weight was 29,25 -grains; whence it appeared that 1,14 grains of common air, part of -which had been contained in the stop-cocks, had entered with the -nitrous gas. - -Whilst it was cooling, from the accidental loosening of the stopper of -the cock, 3 grains more of common air entered.[19] - -[19] That no greater contraction took place depended on the solution -of the nitrous acid formed in the nitrous gas; a phænomenon to be -explained hereafter. - -The communication was now made between the globe and the mercurial -airholder containing oxygene. 64 cubic inches were slowly pressed in, -when the outside of the globe became warmer, and the color on the -inside changed to a very dark orange. As it cooled, 6 cubic inches more -slowly entered; but no new increase of temperature, or change of color -took place. - -The globe being now completely cold, was stopped, removed, and -weighed; it had gained 24,5 grains, from whence it appears that 0,4 -grains of common air contained in the stop-cocks, had entered with the -oxygene.[20] - -[20] I judged it expedient always to ascertain the quantity of air in -the stop-cocks by weight, as it was impossible to join them so as to -have always an equal capacity. The upper tubes of the two stop-cocks -not joined, contained nearly an inch and half. - -To absorb the nitrous acid gas, 41 grains of water were introduced by -the tube of the stop-cock, which though closed as rapidly as possible, -must have suffered nearly,5 grains of air to enter at the same time, as -the increase of weight was 41,5 grains. The dark orange of the globe -diminished rapidly; it became warm at the bottom, and moist on the -sides. After a few minutes the color had almost wholly disappeared. - -To ascertain the quantity of aëriform fluid absorbed, the globe was -again attached to the mercurial air apparatus, containing 140 cubic -inches of common air. When the communication was made, 51 cubic inches -rushed in, and it gained in weight 16,5 grains. - -A quantity of fluid equal to 54 grains was now taken out of the globe. -On examination it proved to be slightly tinged with green, and occupied -a space equal to that filled by 41,5 grains of water. Its specific -gravity was consequently 1,301. - -To ascertain if any unabsorbed aëriform nitrous acid remained in the -globe, 13 grains of solution of ammonia were introduced in the same -manner as the water, and after some minutes, when the white vapor -had condensed, the communication was again made with the mercurial -airholder containing common air. A minute quantity entered, which could -not be estimated at more than three fourths of an inch, and the globe -was increased in weight about 13,25 grains.[21] - -Common air was now thrown into the globe till the residual gases of -the experiment were judged to be displaced; it weighed 2106,5 grains, -that is, 40 grains more than it had weighed when filled with common air -before the experiment.[22] - -[21] That is, by the solution of ammonia, and air. - -[22] The following is an account of the increase and diminution of -weight of the globe, as it was noted in the journal. - - Globe filled with common air gr. 2066,5 - After exhaustion 2034,5 - After introduction of nitrous gas, 82 cubic inches 2064,25 - After the accidental admission of common air 2067,25 - After the admission of oxygene 2091,75 - —— —— 41 grains of water 2133,25 - —— —— 51 cubic inches of air 2149,75 - Taken out 54 grains of solution 2095,75 - Introduced 13 grains of ammoniacal solution 2109,25 - After introduction of common air 2106,5 - - -And if from those 40 grains we take 13 for the solution of ammonia -introduced, the remainder, 27, will be the quantity of solution of -nitrous acid in water remaining in the globe, which added to 54, equals -81 grains, the whole quantity formed; but if from this be taken 41 -grains, the quantity of water, the remainder 40 grains, will be the -quantity of nitrous acid gas absorbed in the solution. - -To find the absolute quantity of nitrous acid formed, we must find -the specific gravity of that absorbed; but as during, and after its -absorption, 17 grains of air, equal to 53,2 cubic inches entered, it -evidently filled such a space. 53,2 cubic inches of it consequently -weigh 40 grains, and 100 cubic inches 75,17 grains. Then,75 cubic -inches weigh,56 grains, and this added to 40, makes 40,56 grains, equal -to 53,95 cubic inches, the whole quantity of aëriform nitrous acid -produced. - -But the quantity of nitrous gas entering into this, allowing for the -nitrogene it contained, is 27,6 grains, equal to about 80,5 cubic -inches; and the oxygene is 40,56-27,6 = to 12,96 grains, or 36,9 cubic -inches. - -V. There could exist in this experiment no circumstance connected with -inaccuracy, except the impossibility of very minutely determining -the quantities of common air which entered with the gases from the -stop-cocks. But if errors have arisen from this source, they must be -very inconsiderable; as will appear from a calculation of the specific -gravity of the nitrous acid gas, founded on the volume of the gases -that entered the globe. - - The air that remained in the globe - after exhaustion was 15 grains = 47[23] cub. in. - The nitrous gas introduced was 82 - Common air 13 - Oxygene 70 - Common air 1 - —— - Whole quantity of air thrown into the globe 213 - From which subtract its capacity 148 - —— - The remainder is 65 - -[23] Decimals are omitted, because the excess of the two first numbers -is exactly corrected by the deficiency of the last. - -And this remainder taken from 80,5 nitrous gas + 36,9 oxygene, leaves -52,4 cubic inches, which is the space occupied by the nitrous acid gas, -and which differs from 53,95 only by 1,55 cubic inches. - -I ought to have observed, that before this conclusive experiment, two -similar ones had been made. In comparing the results of one of them, -performed with the assistance of my friend, Mr. JOSEPH PRIESTLEY, Dr. -PRIESTLEY’S eldest son, and chiefly detailed by him in the journal, I -find a coincidence greater than could be even well expected, where the -processes are so complex. According to that experiment, 41,5 grains -of nitrous acid gas fill a space equal to 53 cubic inches, and are -composed of nearly 29 nitrous gas, and 12,5 oxygene. - -We may then conclude, First, that 100 cubic inches of nitrous acid, -such as exists in the[24] aëriform state saturated with oxygene, at -temperature 55°, and atmospheric pressure 30,1 weigh 75,17 grains. - -[24] As is evident from the superabundant quantity of oxygene thrown -into the globe. - -Secondly, that 100 grains of it are composed of 68,06 nitrous gas, and -31,94 oxygene. Or assuming what will be hereafter proved, that 100 -parts of nitrous gas consist of 55,95 oxygene, and 44,05 nitrogene, of -29,9 nitrogene, and 70,1 oxygene; or taking away decimals, of 30 of the -one to 70 of the other. - -Thirdly, that 100 grains of pale green solution of nitrous acid in -water, of specific gravity 1,301, are composed of 50,62 water, and 49,38 -acid of the above composition. - -VI. Having thus ascertained the composition of a standard acid, my next -object was to obtain it in a more condensed state, as it was otherwise -impossible to saturate it to its full extent with nitrous gas. But this -I could effect in no other way than by comparing mixtures of known -quantities of water, and acids of different specific gravities and -colors, with the acid of 1,301. - -For the purpose of combining my acids with water, I made use of a -cylinder about 8 inches long, and,3 inches in diameter, accurately -graduated to grain measures, and furnished with a very tight stopper. - -The concentrated acid was first slowly poured into it, and the water -gradually added till the required specific gravity was produced;[25] -the cylinder being closed and agitated after each addition, so as to -produce combination without any liberation of elastic fluid. - -[25] The weight of the acid poured into the cylinder being known, its -specific gravity was known from the space it occupied in the phial. -The weight of water being likewise known, the specific gravity of the -solution, when the common temperature was produced, was given by the -condensation. - -After making a number of experiments with acids of different colors -in this advantageous way, I at length found that 90 grains of a deep -yellow acid, of specific gravity 1,5, became, when mingled at 40° with -77,5 grains of water, of specific gravity 1,302, and of a light green -tinge, as nearly as possible resembling that of the standard acid. - -Supposing, then, that these acids contain nearly the same relative -proportions of oxygene and nitrogene, 100 grains of the deep yellow -acid of 1,5, are composed of 91,9 grains true nitrous acid,[26] and 8,1 -grains of water. - -[26] That is, such as it exists in the aëriform state at 55°. From the -strong affinity of nitrous acid for water, we may suppose that this -acid gas contains a larger proportion of it than the other gases. - -To ascertain the difference between the composition of this acid, -and that of the pale, or nitric acid, of the same specific gravity, -I inserted 150 grains of it into a small cylindrical mattrass of the -capacity of,5 cubic inches, accurately graduated to grain measures, -and connected by a curved tube with the water apparatus. After heat had -been applied to the bottom of the mattrass for a few minutes, the color -of the fluid gradually changed to a deep red, whilst the globules of -gas formed at the bottom of the acid, were almost wholly absorbed in -passing through it. In a short time deep red vapour began to fill the -tube, and being condensed by the water in the apparatus, was converted -into a bright green fluid, at the same time that minute globules of -gas were given out. As the heat applied became more intense, a very -singular phænomenon presented itself; the condensed vapor, increased -in quantity, at length filled the curvature of the tube, and when -expelled, formed itself into dark green spherules, which sunk to the -bottom of the water, rested for a moment, and then resolved themselves -into nitrous gas.[27] - -[27] This appearance will be explained hereafter. - -When the acid was become completely pale, it was suffered to cool, -and weighed. It had lost near 15 grains, and was of specific gravity -1,491. 2 cubic inches and quarter of nitrous gas only were collected. - -From this experiment evidently no conclusions could be drawn, as the -nitrous gas had carried over with it much nitrous acid (in the form of -what Dr. Priestley calls nitrous vapor) and was partially dissolved -with it in the water.[28] - -[28] This phænomenon will be particularly explained hereafter. - -To ascertain, then, the difference between the pale and yellow acids, I -was obliged to make use of synthesis, compared with analysis, carried -on in a different mode, by means of the following apparatus. - -VII. To the stop-cock of the upper cylinder of the mercurial airholder, -a capillary tube was adapted, bent so as to be capable of introduction -into an orifice in the stopper of a graduated phial similar to that -employed for mingling acids with water, and sufficiently long to reach -the bottom. With another orifice in the stopper of the phial was -connected a similar tube curved, for the purpose of containing a fluid, -and of increased diameter at the extremity.[29] - -50 cubic inches of pure nitrous gas[30] were thrown into the mercurial -apparatus. The graduated phial, containing 90 grains of nitric acid, of -specific gravity 1,5, was placed on the top of the airholding cylinder, -and made to communicate with it by means of the stop-cock and first -tube. Into the second tube a small quantity of solution of potash was -placed. When all the junctures were carefully cemented, by pressing on -the airholder, the nitrous gas was slowly passed into the phial, and -absorbed by the nitrous acid it contained; whilst the small quantities -of nitrogene evolved, slowly drove forward the solution in the curved -tube; from the height of which, as compared with that of the mercury in -the conducing tube, the pressure on the air in the cylinder was known. - -In proportion as the nitrous gas was absorbed, the phial became warm, -and the acid changed color; it first became straw-colored, then pale -yellow, and when about 7½ cubic inches had been combined with it, -bright yellow. It had gained in weight nearly 3 grains, and was become -of specific gravity 1,496. - -[29] The outline only of this apparatus is given here, as far as was -necessary to make the experiment intelligible; a detailed account of -it, and of its general application, will be given in the appendix. - -[30] That is, from nitrous acid and mercury. - -This experiment afforded me an approximation to the real difference -between nitric and yellow nitrous acid; and learning from it that -nitric acid was diminished in specific gravity by combination with -nitrous gas, I procured a pale acid of specific gravity 1,504.[31] -After this acid had been combined in the same manner as before, with -about 8 cubic inches of nitrous gas,[32] it became nearly of specific -gravity 1,5, and had gained in weight about 3 grains. - -[31] A pale acid of 1.52, by being converted into yellow acid, became -nearly of specific gravity 15,1. - -[32] It is impossible to ascertain the quantity of gas absorbed to more -than a quarter of a cubic inch, as the first portions of nitrous gas -thrown into the graduated cylinder are combined with the oxygene of the -common air in it, to form nitrous acid, and hence the slight excess of -weight. - -Assuming the accuracy of this experiment as a foundation for -calculation, I endeavoured in the same manner to ascertain the -differences in the composition of the orange colored acids, and the -acids containing still larger proportions of nitrous gas. - -93 grains of the bright yellow acid of 1,5 became, when 6 cubic inches -of gas had been passed through it, orange colored and fuming, whilst -the undissolved gas increased in quantity so much as to render it -impossible to confine it by the solution of potash. When 9 cubic inches -had passed through, it became dark orange. It had gained in weight -2,75 grains, and was become of specific gravity 1,48 nearly. Hence it -was evident that much nitrous gas had passed through it undissolved. -25 cubic inches more of nitrous gas were now slowly sent through it: -it first became of a light olive, then of a dark olive, then of a -muddy green, then of a bright green, and lastly of a blue green. After -its assumption of this color, the gas appeared to pass through it -unaltered, and large globules of fluid, of a darker green than the -rest, remained at the bottom of the cylinder, and when agitated, did -not combine with it. The increase of weight was only 1 grain, and the -acid was of specific gravity 1,474 nearly. - -In this experiment it was evident that the unabsorbed nitrous gas -had carried over with it a considerable quantity of nitrous acid. I -endeavoured to correct the errors resulting from this circumstance, -by connecting the curved tube first with a small water apparatus, and -afterwards with a mercurial apparatus; but when the water apparatus -was used, the greater part of the unabsorbed gas was dissolved with -the nitrous acid it held in solution, by the water; and when mercury -was employed, the nitrous acid that came over was decomposed, and the -quantity of nitrous gas evolved, in consequence increased. - -As it was possible that a small deficiency of weight might arise from -the red vapor given out during the processes of weighing and examining -the acid in the last experiment, 35 cubic inches of nitrous gas were -very slowly passed through 90 grains of pale nitrous acid, of specific -gravity 1,5: it became of similar appearance to that just described, -had gained in weight 6,75 grains, and was become of specific gravity -1,475. - -These experiments did not afford approximations sufficiently accurate -towards the composition of deoxygenated acids, containing more nitrous -gas than the dark orange colored. To obtain them, a solution consisting -of 94,25 grains of blue green, or perfectly nitrated acid, (if we -may be allowed to employ the term), of specific gravity 1,475, was -inserted into a graduated phial, and connected by a curved tube, with -the mercurial airholder; in the conductor of which a small quantity of -water was inserted to absorb the nitrous acid which might be carried -over by the gas. Heat was slowly applied to the phial, and nitrous gas -given out with great rapidity. When 4 cubic inches were collected, -the acid became dark olive, when 9 dark red, when 13 bright orange, -and when 18 pale. It had lost 31 grains, and when completely cool, -was of specific gravity 1,502 nearly. The water in the apparatus was -tinged of a light blue; from whence we may conclude that some of the -nitrous gas was absorbed by it with the nitrous acid: but it will be -hereafter proved that the orange colored acid is the most nitrated acid -capable of combining undecompounded with water, and that the color it -communicates to a large quantity of water, is light blue. If then we -take 6,1 grains, the quantity of gas collected, from 31 the loss, the -remainder is 24,9, which reasoning from the synthetical experiment, -may be supposed to contain nearly 3 cubic inches of nitrous gas. -Consequently, 94,25 grains of dark green acid, of specific gravity -1,475, are composed of nearly 21 cubic inches, or 7,2 grains of nitrous -gas, and 87,05 grains of pale nitrous acid, of 1,504. - -VIII. Comparing the different synthetical and analytical experiments, -we may conclude with tolerable accuracy, that 92,75 grains of bright -yellow, or standard acid of 1,5, are composed of 2,75 grains of nitrous -gas, and 90 grains of nitric acid of 1,504; but 92,75 grains of -standard acid contain 85,23 grains of nitrous acid, composed of about -27,23 of oxygene, and 58, nitrous gas: now from 58, take 2,75, and the -remainder 55,25, is the quantity of nitrous gas contained in 90 grains -of nitric acid of 1,504; consequently, 100 grains of it are composed -of 8,45 water, and 91,55 true acid, containing 61,32 nitrous gas, and -30,23 oxygene; or 27,01 nitrogene, and 64,54 oxygene: and the nitrogene -in nitric acid, is to the oxygene as 1 to 2,389. - -IX. My ingenious friend, Mr. JAMES THOMSON, has communicated to me some -observations relating to the composition of nitrous acid (that is, the -orange colored acid), from which he draws a conclusion which is, in my -opinion, countenanced by all the facts we are in possession of, namely, -“that it ought not to be considered as a distinct and less oxygenated -state of acid, but simply as nitric or pale acid, holding in solution, -that is, loosely combined with, nitrous gas.”[33] - -[33] In a letter to me, dated Oct. 28, 1799, after giving an account -of some experiments on the phlogistication of nitric acid by heat and -light, he says, “It was from an attentive examination of the manner in -which the nitric acid was phlogisticated in these experiments, that -I was confirmed in the suspicion I had long before entertained, of -the real difference between the _nitrous_ and _nitric_ acids. It is -not enough to shew that in the _nitrous_ acid, (that is, the nitric -holding nitrous gas in solution), the proportion of oxygene in the -whole compound is less than that entering into the composition of the -nitric acid, and that it is therefore less oxygenated. By the same -mode of reasoning we might prove that water, by absorbing carbonic -acid gas, became less oxygenated, which is absurd. Should any one -attempt to prove (which will be necessary to substantiate the generally -received doctrine) that the oxygene of the nitrous gas combines with -the oxygene of the acid, and the nitrogene, in like manner, so that -the resulting acid, when nitrous gas is absorbed by nitric acid, is a -binary combination of oxygene and nitrogene, he would find it somewhat -more difficult than he at first imagined; it appears to me impossible. -It is much more consonant with experiment to suppose that nitrous acid -is nothing more than nitric acid holding nitrous gas in solution, which -might in conformity to the principles of the French nomenclature, be -called nitrate of nitrogene. The difficulty, and in some cases the -impossibility, of forming nitrites, arises from the weak affinity -which nitrous gas has for nitric acid, compared with that of other -substances; and the decomposition of nitrous acid (that is, nitrate of -nitrogene) by an alkaline or metallic substance, is perfectly analogous -to the decomposition of any other nitrate, the nitrous gas being -displaced by the superior affinity of the alkali for the acid. - -“Agreeable to this theory, the salts denominated _nitrites_ are in fact -triple salts, or ternary combinations of nitric acid, nitrous gas, and -salifiable bases.” - -This theory is perfectly new to me. Other Chemists to whom I have -mentioned it, have likewise considered it as new. Yet in a subsequent -letter Mr. Thomson mentions that he had been told of the belief of a -similar opinion among the French Chemists. - -It is impossible to call any substance a simple acid that is incapable -of entering undecompounded into combination with the alkalies, &c; but -it will appear hereafter that the salts called in the new nomenclature -_nitrites_, cannot be directly formed. If, indeed, it could be proved, -that the heat produced by the combination of nitrous acid with -salifiable bases, was the only cause of the partial decomposition of -it, and that when this process was effected in such a way as to prevent -increase of temperature, no nitrous gas was liberated, the common -theory might have some foundation; but though dilute phlogisticated -nitrous acid combines[34] with alkaline solutions without -decomposition, yet no excess of nitrous gas is found in the solid salt: -it is either disengaged in proportion as the water is evaporated, or it -absorbs oxygene from the atmosphere, and becomes nitric acid. - -[34] In some experiments made on the nitrites of potash, and of -ammoniac, before I was well acquainted with the composition of nitric -acid, I found that a light olive-colored acid of 1,28, was capable -of being saturated by weak solutions of potash and ammoniac, without -losing any nitrous gas; but after the evaporation of the neutralised -solution, at very low temperatures, the salts in all their properties -resembled _nitrates_. - -In proportion as the nitrous acids contain more nitrous gas, so in -proportion do they more readily give it out. From the blue green acid -it is liberated slowly at the temperature of 50°, and from the green -likewise on agitation. The orange coloured and yellow acids do not -require a heat above 200° to free them of their nitrous gas; and all -the colored acids, when exposed to the atmosphere absorb oxygene, and -become by degrees pale. - -If the nitrous vapour, i. e. such as is disengaged during the -_denitration_ of the colored acids, was capable of combining with the -alkalies, it might be supposed a distinct acid, and called nitrous -acid; and the acids of different colors might be considered simply as -compounds of this acid with nitric acid; but it appears to be nothing -more than a solution of nitric acid in nitrous gas, incapable of -condensation, undecompounded, and when decompounded and condensed, -constituting the dark green acid, which is immiscible with water,[35] -and uncombinable with the alkalies.[36] - -[35] As is evident from the curious appearance of the dark green -spherules, repulsive both to water, and light green acid. - -[36] That is, undecompounded. - -It seems therefore reasonable, till we are in possession of new lights -on the subject, to consider, with Mr. Thomson, the deoxygenated or -nitrous acids simply as solutions of nitrous gas composed of sulphuric -acid, metallic oxides, and nitrous gas.[37] - -[37] The existence of these bodies will be hereafter proved. - -Supposing the truth of these principles according to the logic of the -French nomenclature, there is no acid to which the term nitrous acid -_ought_ to be applied; but as it has been used to signify the acids -holding in solution nitrous gas, it is perhaps better still to apply it -to those substances, than to invent for them new names. A nomenclature, -accurately expressing their constituent parts, would be too complex, -and like all other nomenclatures founded upon theory, liable to -perpetual alterations. Their composition is known from their specific -gravity and their colors; hence it is better to denote it by those -physical properties: thus orange nitrous acid, of specific gravity -1,480, will signify a solution of nitrous gas in nitric acid, in which -the nitric acid is to the nitrous gas, nearly as 87 to 5, and to the -water as 11 to 1. - -X. The estimation of the composition of the yellow and orange colored -nitrous acids given in the following table, may be considered as -tolerably accurate, being deduced from the synthetical experiments -in the sixth section, compared with the analytical ones. But as -in the synthetical experiment, when the acid became green, it was -impossible to ascertain the quantity of nitrous gas that passed through -it unabsorbed, and as in the analysis the quantity of nitrous gas -dissolved by the water at different periods of the experiment could not -be ascertained, the accounts of the composition of the green acids must -be considered only as very imperfect approximations to truth. - - -TABLE I. - - _Containing Approximations to the quantities - of NITRIC ACID, NITROUS GAS, and WATER in - NITROUS ACIDS, of different colors and specific - gravities._ - +------------------+---+----------+---+--------+-------+---------+ - | 100 | | Specific | | Nitric | Water | Nitrous | - | Parts | | Gravity | | Acid | | gas | - +------------------+---+----------+---+--------+-------+---------+ - |Sol. Nitric Acid | | 1,504 | c | 91,55 | 8,45 | — — | - |Yellow Nitrous[38]| | 1,502 | o | 90,5 | 8,3 | 1,2 | - |Bright Yellow | o | 1,500 | n | 88,94 | 8,10 | 2,96 | - |Dark Orange | f | 1,480 | t | 86,84 | 7,6 | 5,56 | - |Light Olive‡ | | 1,479 | a | 86,00 | 7,55 | 6,45 | - |Dark Olive‡ | | 1,478 | i | 85,4 | 7,5 | 7,1 | - |Bright Green‡ | | 1,476 | n | 84,8 | 7,44 | 7,76 | - |Blue Green[39] | | 1,475 | | 84,6 | 7,4 | 8,00 | - +------------------+---+----------+---+--------+-------+---------+ - ‡ = “FOOTNOTE {38}” - -[38] The blue green acid is not homogeneal in its composition, it is -composed of the blue green spherules and the bright green acid. The -blue green spherules are of greater specific gravity than the dark -green acid, probably because they contain little or no water. - -[39] The composition of the acids thus marked, is given from -calculations. - - -TABLE II. - - _Binary Proportions of OXYGENE and NITROGENE in - NITRIC and NITROUS ACIDS._[40] - - +---------------+---+-------+--------+-------------+-------+-------+ - | 100 Parts | |Oxygene| Nitro- | | Nitro-|Oxygene| - | | | | gene | | gene | | - +---------------+---+-------+--------+-------------+-------+-------+ - |Nitric Acid | c | 70,50 | 29,50 | | 1 | 2,389 | - +---------------+ o +-------+--------+ +-------+-------+ - |Bright yellow | n | 70,10 | 29,90 | | 1 | 2,344 | - | Nitrous | t | | |Proportions. | | | - +---------------+ a +-------+--------+ Nitrogene. +-------+-------+ - |Orange coloured| i | 69,63 | 30,37 | Unity. | 1 | 2,292 | - +---------------+ n +-------+--------+ +-------+-------+ - |Dark Green | | 69,08 | 30,92 | | 1 | 2,230 | - +---------------+---+-------+--------+-------------+-------+-------+ - -[40] Nitrous gas contains 44,05 Nitrogene, and 55,95 Oxygene, as has -been said before. - -XI. I have before mentioned that dilute nitric acids are incapable of -dissolving so much nitrous gas in proportion to their quantities of -true acid, as concentrated ones. During their absorption of it, they -go through similar changes of color; 330 grains of nitric acid, of -specific gravity 1,36, after 50 cubic inches of gas had been passed -through it, became blue green, and of specific gravity 1,351. It had -gained in weight but 3 grains; and when the nitrous gas was driven -from it by heat into a water apparatus, but 7 cubic inches were -collected.[41] - -From the diminution of specific gravity of nitric acid by combination -with nitrous gas, and from the smaller attraction of nitric acid for -nitrous gas, in proportion as it is diluted, it is probable that the -nitrated acids, in their combinations with water, do not contract so -much as[42] nitric acids of the same specific gravities. The affinities -resulting from the small attraction of nitrous gas for water, and its -greater attraction for nitric acid, must be such as to lessen the -affinity of nitric acid and water for each other. - -[41] A great portion of it, of course, dissolved in the water with the -nitrous acid carried over. - -[42] Their changes of volume, corresponding to changes of temperature, -most probably, are likewise different. - -Hence it would require an infinite number of experiments to ascertain -the real quantities of acid, nitrous gas, and water, contained in -the different diluted nitrous acids; and after these quantities were -determined, they would probably have no important connection with the -chemical arrangement. As yet, our instruments of experiment are not -sufficiently exact to afford us the means of ascertaining the ratio in -which the attraction of nitric acid[43] for water diminishes in its -progress towards saturation. - -[43] Probably in the ratio of the square of the quantity of water -united to it. - -The estimations in the following table, of the real quantities of -nitric acid in solutions of different specific gravities, were deduced -from experiments made in the manner described in section VI, except -that the phial employed was longer, narrower, and graduated to half -grains. The temperature, at the time of combination, was from 40° to -46°. - - -TABLE III. - - _Of the Quantities of True NITRIC ACID in solutions - of different SPECIFIC GRAVITIES._ - - +----------------+-----+-------------+-------+ - |100 Parts Nitric| |True Acid[44]| Water | - |Acid of specific| | | | - | gravity | | | | - +----------------+ +-------------+-------+ - | 1,5040 | c | 91,55 | 8,45 | - | 1,4475 | o | 80,39 | 19,61 | - | 1,4285 | n | 71,65 | 28,35 | - | 1,3906 | t | 62,96 | 37,04 | - | 1,3551 | a | 56,88 | 43,12 | - | 1,3186 | i | 52,03 | 47,97 | - | 1,3042 | n | 49,04 | 50,96 | - | 1,2831 | | 46,03 | 53,97 | - | 1,2090 | | 45,27 | 54,73 | - +----------------+-----+-------------+-------+ - - -[44] The quantities of Oxygene and Nitrogene in any solution, may be -thus found—— Let A = the true acid, X the oxygene, and Y the nitrogene. - -Then - - 238 A A - X = —————— and Y = ———— - 239 239 - - -XII. The blue green spherules mentioned in section V. produced by -the condensation of nitrous vapor, and by the combination of nitric -acid with nitrous gas, may be considered as saturated solutions of -nitrous gas in nitric acid. The combinations of nitric acid and nitrous -gas containing a larger proportion of nitrous gas, are incapable of -existing in the fluid state at common temperatures; and, as appears -from the first experiment, an increase of volume takes place during -their formation. They consequently ought to be looked upon as solutions -of nitric acid in nitrous gas, identical with the nitrous vapor of -Priestley. - -From the researches of this great discoverer, we learn that nitrous -vapor is decomposable, both by water and mercury. Hence it is almost -impossible accurately to ascertain its composition. In one of his -experiments,[45] when more than 130 grains of strong nitrous acid were -exposed for two days to nearly 247 cubic inches of nitrous gas, over -water: about half of the acid was dissolved, and deposited with the gas -in the water.[46] - -[45] Experiments and Observations; last edition, vol. 1, page 384. - -[46] Nitrous gas, holding in solution nitrous acid, is more readily -absorbed by water than when in its pure form, from being presented to -it in a more condensed state in the green acid, formed by the contact -of water and nitrous vapor. - -XIII. In comparing the results of my fundamental experiment on the -composition of nitrous acid, with those of Cavendish, the great -coincidence between them gave me very high satisfaction, as affording -additional proofs of accuracy. If the acid formed in the last -experiment of this illustrious philosopher be supposed analogous to the -light green acid formed in my first experiment, our estimations will be -almost identical. - -Lavoisier’s account of the composition of the nitric and nitrous -acids, has been generally adopted. According to his estimation, these -substances contain a much larger quantity of oxygene than I have -assigned to them. - -The fundamental experiments of this great philosopher were made at an -early period of pneumatic chemistry,[47] on the decomposition of nitre -by charcoal; and he considered the nitrogene evolved, and the oxygene -of the carbonic acid produced in this process, as the component parts -of the nitric acid contained in the nitre. - -[47] Mem. des Savans Etrangers, v. xi. 226. Vide Kirwan sur le -phlogistique pag. 110. - -I have before mentioned the liberation of nitrous acid, in the -decomposition of nitre by combustible bodies; and I had reasons for -suspecting that this circumstance was not the only source of inaccuracy. - -That my suspicions were well founded, will appear from the following -experiments: - -EXPERIMENT _a_. I introduced into a strong glass tube, 3 inches long, -and nearly,3 wide, a mixture of 10 grains of pulverised, well burnt -charcoal, and 60 grains of nitre. It was fired by means of touch-paper, -and the tube instantly plunged under a jar filled with dry mercury. -A quantity of gas, clouded with dense white vapor was collected. -When this vapor was precipitated, so that the surface of the mercury -could be seen, it appeared white, as if acted on by nitrous acid. On -introducing a little oxygene into the jar, copious red fumes appeared. - -EXP. _b_. A similar mixture was fired[48] under the jar, the top of -the mercury being covered with a small quantity of red cabbage juice, -rendered green by an alkali. This juice, examined when the vapor -was precipitated, was become red, and on introducing to it a little -carbonate of potash, a slight effervescence took place. - -[48] In this experiment, as well as in the last, some of the mixture -was thrown into the jar undecompounded. - -EXP. _c_. Five grains of charcoal, and 20 of nitre, were now fired in -the same manner as before, the mercury being covered with a stratum -of water. After the precipitation of the vapor on the introduction of -oxygene, no red fumes were perceived. - -EXP. _d_. 30 grains of nitre, 5 of charcoal, and five of silicious -earth,[49] were now mingled and fired. The gas received under mercury -was composed of 18 carbonic acid, and nearly 12 nitrogene.[50] A -little muriatic acid was poured on the residuum in the tube; a slight -effervescence took place. - -[49] To detach the potash from the carbonic acid. - -[50] This nitrogene contained a little nitrous gas, as it gave red -fumes when exposed to the air. The free nitrous acid was decomposed by -the mercury, as it was not covered with water. - -EXP. _e_. The top of the mercury in the jar was now covered with a -little diluted muriatic acid, and a small glass tube filled with a -mixture of 3 grains of charcoal, and 20 nitre. After the deflagration, -the tube itself with the residuum it contained, were thrown into the -jar. The carbonic acid was quickly detached from them by the muriatic -acid, and the whole quantity of gas generated in the process, obtained; -it measured 15 cubic inches. - -4 cubic inches of it exposed to solution of potash, diminished to -1⁴/₁₀; 7 of the remainder, with 8 of oxygene, gave only 12. - -EXP. _f_. 60 grains of nitre, and 9 of charcoal were fired, the -top of the mercury in the jar being covered with water. After the -deflagration, the tube that had contained them was introduced, and -the carbonic acid contained by the carbonate of potash, disengaged by -muriatic acid. 30 measures of the gases evolved were exposed to caustic -potash; 20 exactly were absorbed, the 10 remaining, with 10 of oxygene, -diminished to 17. - -EXP. _g_. A mixture of nitre and charcoal were deflagrated over a -little water in the mercurial jar: after the precipitation of the -vapor, the water was absorbed by filtrating paper. This filtrating -paper, heated in a solution of potash, gave a faint smell of ammoniac. - -EXP. _h_. Water impregnated with the vapor produced in the -deflagration, was heated with quicklime, and presented separately to -three persons accustomed to chemical odors. Two of them instantly -recognised the ammoniacal smell, the other could not ascertain it. -Paper reddened with cabbage juice was quickly turned green by the vapor. - -These experiments are sufficient to shew that the decomposition of -nitre by charcoal is a very complex process, and that the intense -degree of heat produced may effect changes in the substances employed, -which we are unable to estimate. - -The products, instead of being simply carbonic acid, and nitrogene, are -carbonic acid, nitrogene, nitrous acid, probably ammonia, and sometimes -nitrous gas. The nitrous acid is disengaged from the base by the -intense heat. Concerning the formation of the ammonia, it is useless to -reason till we have obtained unequivocal testimonies of its existence; -it may be produced either by the decomposition of the water contained -in the nitre, by the combination of its oxygene with the charcoal, and -of its nascent hydrogene with the nitrogene of the nitric acid; or from -some unknown decomposition of the potash. - -As neither Lavoisier nor Berthollet found nitrous gas produced in -the decomposition of nitre by charcoal, when a water apparatus was -employed; and as it was not uniformly evolved in my experiments, the -most probable supposition is, that it arises from the decomposition of -a portion of the free nitrous acid intensely heated, by the mercury. - -In none of my experiments was the whole of the nitre and charcoal -decomposed, some of it was uniformly thrown with the gases into the -mercurial apparatus. The nitrogene evolved, as far as I could ascertain -by the common tests, was mingled with no inflammable gas. - -If we consider experiment _f_ as accurate, with regard to the relative -quantities of carbonic acid and nitrogene produced, they are to each -other nearly as 20 to 8; that is, allowing 2 for the nitrous gas, and -consequently, reasoning in the same manner as Lavoisier, concerning the -composition of nitric acid, it should be composed of 1 nitrogene to -3,38 oxygene. But though the quantity of oxygene in this estimation is -far short of that given in his, yet still it is too much. From whatever -source the errors arise, whether from the evolution of phlogisticated -nitrous acid, or the decomposition of water, or the production of -nitrous gas, they all tend to increase the proportion of the carbonic -acid to the nitrogene. - -I am unacquainted with any experiment from which accurate opinions -concerning the different relative proportions of oxygene and nitrogene -in the nitric and nitrous acids could be deduced. Lavoisier’s -calculation is founded on his fundamental experiment, and on the -combination of nitrous gas and oxygene. - -Dr. Priestley’s experiment mentioned in section 12, on the absorption -of nitrous gas by nitrous acid, from which Kirwan[51] deduces the -composition of the differently colored nitrous acids, was made over -water, by which, as is evident from a minute examination of the -facts[52], the greater portion of the nitrous gas employed was absorbed. - -[51] Essay on phlogiston. - -[52] Dr. Priestley says, “Having filled a phial containing exactly -the quantity of four pennyweights of water, with strong, pale, yellow -spirit of nitre, with its mouth quite close to the top of a large -receiver standing in water, I carefully drew out almost all the common -air, and then filled it with nitrous air; and as this was absorbed, -I kept putting in more and more, till in less than two days it had -completely absorbed 130 ounce measures. Presently after this process -began, the surface of the acid assumed a deep orange color, and when 20 -or 30 ounce measures of air were absorbed, it became green at the top: -this green descended lower and lower, till it reached the bottom of the -phial. Towards the end of the process, the evaporation was perceived to -be very great, and when I took it out, the quantity was found to have -diminished to one half. Also it had become, by means of this process, -and the evaporation together, exceeding weak, and was rather blue than -green.” - -_Experiments and Observations_, vol. 1, p. 384. Last edition. XIV. -The opinions heretofore adopted respecting the quantities of real or -true acid in solutions of nitrous acid of different specific gravities, -have been founded on experiments made on the nitro-neutral salts, -the most accurate of which are those of Kirwan, Bergman, and Wenzel. -The great difference in the results of these celebrated men, proves -the difficulty of the investigation, and the existence of sources of -error.[53] Kirwan deduces the composition of the solutions of nitrous -acid in water, from an experiment on the formation of nitrated soda. -In this experiment, 36,05 grains of soda were saturated by 145 grains -of nitrous acid, of specific gravity 1,2754. By a test experiment, he -found the quantity of salt formed to be 85,142 grains.[54] Hence he -concludes that 100 parts of nitrous acid, of specific gravity 1,5543, -contain 73,54 of the strongest, or most concentrated acid. - -[53] See Mr. Keir’s excellent observations on this subject. Chem. Dict. -Art. Acid. - -[54] Irish Transactions, vol. 4, p. 34. - -Supposing his estimation perfectly true, 100 parts of the aëriform acid -of 55° would be composed of 74,54 of his real acid, and 25,46 water. -In examining, however, one of his later experiments,[55] we shall find -reasons for concluding, that the acid in nitrated soda cannot contain -much less water than the aëriform acid. A solution of carbonated soda, -containing 125 grains of real alkali, was saturated by 306,2 grains of -nitrous acid, of specific gravity 1,416. The evaporation was carried -on in a temperature not exceeding 120°, and the residuum exposed to a -heat of 400° for six hours, at the end of which time it weighed 308 -grains. Now according to my estimation, 306 grains of nitric acid, of -1,416, should contain 215 true acid; and we can hardly suppose, but -that during the evaporation and consequent long exposure to heat, some -of the nitrated soda was lost with the water. - -[55] Addit. Obs. pag. 74. - -Bergman estimates the quantity of water in this salt at 25, and the -acid at 43 per cent; but his real acid was not so concentrated as -Kirwan’s, consequently the nitric acid in nitrated soda should contain -more water than my true acid. - -Wenzel, from an experiment on the composition of nitrated soda, -concludes that it contains 37,48 of alkali, and 62,52 of nitrous acid; -and 1000 of this acid, from Kirwan’s calculation, contain 812,6 of his -real acid; consequently, 100 parts of my aëriform acid should contain -93,28 of Wenzel’s acid, and 6,72 of water. - -I saturated with potash 54 grains of solution of nitric acid, of -specific gravity 1,301. Evaporated at about 212°, it produced 66 grains -of nitre. This nitre exposed to a higher temperature, and kept in -fusion for some time, was reduced to 60 grains. - -Now from the table, 54 of 1,301, should contain 26,5 of true acid. But -according to Kirwan’s estimation, 100 parts of dry nitre contain 44[56] -of his real acid, with 4 water; consequently 60 should contain 26,4. - -[56] Additional Observations, page 70. - -Again, 90 grains of acid, of specific gravity 1,504, saturated with -potash, and treated in the same manner, gave 173 grains of dry nitre. -Consequently, 100 parts of it should contain 47,3 grains of true acid. - -Now Lavoisier[57] allows about 51 of dry acid to 100 grains of nitre, -and Wenzel 52. - -From Berthollet’s[58] experiments, 100 grains of nitre, in their -decomposition by heat, give out nearly 49 grains of gas.[59] - -Hence it appears that the aëriform acid, that is, the true acid of my -table, contains rather less water than the acid supposed to exist in -nitre. - -[57] Elements, pag. 103, Kerr’s Translation. - -[58] Mem. Acad. 1787. - -[59] As well as oxygene and nitrogene, Mr. Watt’s experiments prove -that much phlogisticated nitrous acid is produced. - - -DIVISION II. - - _EXPERIMENTS and OBSERVATIONS on the composition of - AMMONIAC and on its combinations with WATER and - NITRIC ACID._ - - -I. _Analysis of AMMONIAC or VOLATILE ALKALI._ - -The formation and decomposition of volatile alkali in many processes, -was observed by Priestley, Scheele, Bergman, Kirwan, and Higgins; but -to Berthollet we owe the discovery of its constituent parts, and their -proportions to each other. These proportions this excellent philosopher -deduced from an experiment on the decomposition of aëriform ammoniac by -the electric spark:[60] a process in which no apparent source of error -exists. - -[60] Journal de Physique, 1786. Tom. 2, pag. 176. - -Since, however, his estimations have been made, the proportions of -oxygene and hydrogene in water have been more accurately determined. -This circumstance, as well as the conviction of the impossibility -of too minutely scrutinizing facts, fundamental to a great mass of -reasoning, induced me to make the following experiments. - -A porcelain tube was provided, open at both ends, and well glazed -inside and outside, its diameter being about,5 inches. To one end of -this, a glass tube was affixed, curved for the purpose of communicating -with the water apparatus. With the other end a glass retort was -accurately connected, containing a mixture of perfectly caustic slacked -lime, and muriate of ammoniac. - -The water in the apparatus for receiving the gases had been previously -boiled, to expel the air it might contain, and during the experiment -was yet warm. - -When the tube had been reddened in a furnace adapted to the purpose, -the flame of a spirit lamp was applied to the bottom of the retort. A -great quantity of gas was collected in the water apparatus; of this the -first portions were rejected, and the last transferred to the mercurial -trough. - -A small quantity examined, did not at all diminish with nitrous gas, -and burnt with a lambent white flame, in contact with common air. - -2¾ of this gas, equal to 110 grain measures, were fired with 2, equal -to 80, of oxygene, in a detonating tube, by the electric spark. They -were reduced to 2¼, or 90. On introducing to the remainder a solution -of strontian, it became slightly clouded on the top, and an absorption -of some grain measures took place. - -It was evident, then, that in this experiment, charcoal[61] had been -somehow present in the tube; which being dissolved by the nascent -hydrogene, had rendered it slightly carbonated, and in consequence made -the results inconclusive. - -[61] Though the tube had never been used, and was apparently clean and -dry on the inside, it must have contained something in the form of -dust, capable of furnishing either hydrocarbonate, or charcoal. - -A tube of thick green glass carefully made clean, was now employed, -inclosed in the porcelain tube. Every other precaution was taken to -prevent the existence of sources of error, and the experiment conducted -as before. - -140 grain measures of the gas produced, fired with 120 of oxygene, -left, in two experiments, nearly 110. Solution of strontian placed in -contact with the residuum, did not become clouded, and no absorption -was perceived. - -Now 150 measures of gas were destroyed, and if we take Lavoisier’s -and Meusnier’s estimation of the composition of water, and suppose -the weight of oxygene to be 35 grains, and that of hydrogene 2,6 the -hundred cubic inches; the oxygene employed will be to the hydrogene as -243 to 576. Put _x_ for the oxygene, and _y_ for the hydrogene. - - Then _x_ + _y_ = 150 - - _x_ : _y_ :: 243 : 576 - - 243_y_ - _x_ = —————— - 576 - - 819_y_ = 86400 - - _y_ = 105 _x_ = 45 - - And 140 - 105 = 35 - -Consequently, the nitrogene in ammoniac is to the hydrogene as 35: 105 -in volume: and 13,3 grains of ammoniac are composed of 10,6 nitrogene, -(supposing that 100 cubic inches weigh 30,45 grains) and 2,7 hydrogene. - -According to Berthollet, the weight of the nitrogene in ammoniac is to -that of the hydrogene as 121 to 29.[62] The difference between this -estimation and mine is so small as to be almost unworthy of notice, and -arises most probably from the slight difference between the accounts -of Lavoisier and Monge, of the composition of water, and the different -weights assigned to the gases employed. - -[62] Journal de Physique, 1786, t. 2, 177. - -We may then conclude, that 100 grains of ammoniac are composed of about -80 nitrogene, and 20 hydrogene. - -The decomposition of ammoniac by heat, as well as by the electric -spark, was first discovered by Priestley. In an experiment[63] when -aëriform ammoniac was sent through a heated tube from a caustic -solution of ammoniac in water, this great discoverer observed that an -inflammable gas was produced, though in no great quantity, and that a -fluid blackened by matter, probably carbonaceous, likewise came over. - -[63] Phil. Trans. vol. 79, page 294. - -In my experiments the whole of the ammoniac appeared to be decomposed; -the quantity of gas generated was immense, and not clouded, as is -usually the case with gases generated at high temperatures. It is -possible, that the larger quantity of water carried over in his -experiment, by its strong attraction for ammoniac in the aëriform -state, might have, in some measure, retarded the decomposition. It -is however, more probable to suppose, that a fissure existed in the -earthen tube he employed, through which a certain quantity of gas -escaped, and coaly matter entered. - -Priestley found that the metallic oxides when strongly heated, -decomposed ammoniac, the metal being revivified and water and nitrogene -produced.[64] The estimations of the composition of ammoniac that may -be deduced from his experiments on the oxide of lead, differ very -little from those already detailed. - -[64] Vol. 2, page 398. - - -II. _Specific gravity of Ammoniac._ - -From the great solubility of ammoniac in water, it is difficult to -ascertain its specific gravity in the same manner as that of a gas -combinable to no great extent with that fluid. It is impossible to -prevent the existence of a small quantity of solution of ammoniac -in the mercurial airholder,[65] or apparatus containing the gas; -and during the diminution of the pressure of the atmosphere on this -solution,[66] a certain quantity of gas is liberated from it, and hence -a source of error. - -[65] Ammoniac generated at a temperature above that of the atmosphere, -always deposits ammoniacal solution during its reduction to the common -temperature. - -[66] By the introduction of aëriform ammoniac into the exhausted globe. - -To ascertain, then, the weight of ammoniac, I employed an apparatus -similar to that used for the absorption of nitrous gas by nitric acid. - -50 cubic inches of gas were collected in the mercurial airholder, from -the decomposition of muriate of ammoniac by lime; thermometer being -58°, and barometer 29,6. - -100 grains of diluted sulphuric acid were introduced into the small -graduated cylinder, which after being carefully weighed, was made to -communicate with the airholder, the curved tube containing a small -quantity of water. The gas was slowly passed into the fluid, and the -globules wholly absorbed before they reached the top; much increase of -temperature being consequent. When the absorption was compleat, the -phial was increased in weight exactly 9 grains. - -This experiment was repeated three times. The difference of weight, -which was probably connected with alterations of temperature and -pressure, never amounted to more than one sixth of a grain. - -We may then conclude, that at temperature 58°, and atmospheric pressure -29,6, 100 cubic inches of ammoniac weigh 18 grains. - -According to Kirwan, 100 cubic inches of alkaline air[67] weigh 18,16 -grains; barometer 30°, thermometer 61. The difference between these -estimations, the corrections for temperature and pressure being made, -is trifling. - -[67] Additional Observations, page 107. - - -III. _Of the quantities of true Ammoniac in Aqueous Ammoniacal -Solutions, of different specific gravities._ - -To ascertain the quantities of ammoniac, such as exists in the aëriform -state, saturated with moisture, in solutions of different specific -gravities, I employed the apparatus for absorption so often mentioned. -Thermometer being 52°, the mercurial airholder was filled with -ammoniacal gas, and the graduated phial, containing 50 grains of pure -water, connected with it. During the absorption of the gas, the phial -became warm. When about 30 cubic inches had been passed through, it was -suffered to cool, and weighed: it had gained 5,25 grains, and the fluid -filled a space equal to that occupied by 57[68] grains of water. - -[68] It is necessary in these experiments, that the greatest care be -observed in the introduction and extraction of the capillary tube. If -it is introduced dry, there will be a source of error from the moisture -adhering to it when taken out. I therefore always wetted it before its -introduction, and took care that no more fluid adhered to it after the -experiment, than before. - -Consequently, 100 grains of solution of ammoniac in water of specific -gravity,9684 contain 9,502 grains of ammoniac. - -The apparatus being adjusted as before, 50 grains of pure water were -now perfectly saturated with ammoniac. They gained in weight 17 -grains, and when perfectly cool, filled a space equal to 74 of water. -Consequently 100 grains of aqueous ammonial solution of specific -gravity,9054 contain 25,37 grams of ammoniac. - -The two solutions were mingled together; but no alteration of -temperature took place. Consequently the resulting specific gravity -might have been found by calculation. - -On mingling a large quantity of caustic solution of ammoniac with ¼ of -its weight of water, of exactly the same temperature, no alteration -of it was perceptible by a sensible thermometer.—Hence the two -experiments[69] being assumed as data, the intermediate estimations in -the following table, were found by calculation. - -[69] Previous to those experiments, I had made a number of others on -the combination of ammoniac with water.—My design was, to ascertain -the diminution of specific gravity for every three grains of ammoniac -absorbed; but this I found impossible. The capillary tube, when -taken out of the phial, always carried with it a minute portion of -the solution, which partially evaporated before it could be again -introduced; and thus the sources of error increased in proportion to -the number of examinations. - - -TABLE IV. - - _Of approximations to the quantities of AMMONIAC, - such as exists in the aëriform state, saturated with - water at 52°, in AQUEOUS AMMONIACAL SOLUTIONS of - different specific gravities._ - - +----------+-----+----------+--------+ - | 100 | | Ammoniac.| Water. | - | Specific | | | | - | Gravity. | | | | - +----------+ +----------+--------+ - | 9054 | | 25,37 | 74,63 | - | 9166 | | 22,07 | 77,93 | - | 9255 | | 19,54 | 80,46 | - | 9326 | c | 17,52 | 82,48 | - | 9385 | o | 15,88 | 84,12 | - | 9435 | n | 14,53 | 85,47 | - | 9476 | t | 13,46 | 86,54 | - | 9513 | a | 12,40 | 87,60 | - | 9545 | i | 11,56 | 88,44 | - | 9573 | n | 10,82 | 89,18 | - | 9597 | | 10,17 | 89,83 | - | 9619 | | 9,60 | 90,40 | - | 9684 | | 9,50 | 90,50 | - | 9639 | | 9,09 | 90,91 | - | 9713 | | 7,17 | 92,83 | - +----------+-----+----------+--------+ - As yet no mode has been discovered for obtaining - gases in a state of absolute dryness; consequently - we are ignorant of the different quantities - of water they hold in solution at different - temperatures. As far as we are acquainted with - the combinations of ammoniac, there is no state - in which it exists so free from moisture, as when - aëriform, at low temperatures. - -That no considerable source of error existed in the two experiments, -is evident from the trifling difference between the estimations of the -quantities of real ammoniac, in the solution of,9684, as found in the -first experiment, and as given by calculation from the last. - -The quantity of ammoniac in a solution of specific gravity not in the -table, may be thus determined—find the difference between the two -specific gravities nearest to it in the table; _d_, and the difference -between their quantities of alkali, _b_; likewise the difference -between the given specific gravity and that nearest to it, _c_. - - - then _d_ : _b_ :: _c_ : _x_ - - _bc_ - and _x_ = ————— - _d_ - -Which, added to the quantity of the lower specific gravity, is the -alkali sought. - -The differences in specific gravity of the solutions of ammoniac at -temperatures between 4O° and 65°[70] are so trifling as to be hardly -ascertainable, by our imperfect instruments, and consequently are -unworthy of notice. - -[70] The expansion from increase of temperature is probably great in -proportion to the quantity of ammoniac in the solution. - -It is possible at very low temperatures to obtain ammoniacal solutions -of less specific gravity than,9, but they are incapable of being kept -for any length of time under the common pressure of the atmosphere. - - -IV. _Combinations of Ammoniac with Nitric Acid, Composition of Nitrate -of Ammoniac, &c._ - -200 grains of ammoniacal solution, of specific gravity,9056, were -saturated by 385,5 grains of nitric acid, of specific gravity 1,306. -The combination was effected in a long phial, the nitrous acid added -very slowly, and the phial closed after every addition, to prevent any -evaporation in consequence of the great increase of temperature.[71] -The specific gravity of the solution, when reduced to the common -temperature, was 1,15. Evaporated at a heat of 212°,[72] it gave 254 -grains of salt of fibrous crystalization. This salt was dissolved in -331 grains of water; the specific gravity of the solution was 1,148 -nearly. - -[71] From the combination. - -[72] I had before proved that at this temperature the salt neither -decomposed nor sublimed. - -Hence it was evident that some of the salt had been lost during the -evaporation. - -To find the quantity lost, fibrous nitrate of ammoniac was dissolved -in small quantities in the solution, the specific gravity of which was -examined after every addition of 3 grains. When 16 grains had been -added to it, it became of 1,15. - -Consequently, the solution composed of 200 grains of ammoniacal, and -of 385,5 of nitric acid solution, contained 262 grains of salt of -fibrous crystalization, and of this salt 8 grains were lost during the -evaporation. - -But the alkali in 200 grains of ammoniacal solution of,9056 = 50,5 -grains. And the true nitric acid in 385,5 grains of solution of 1,306 = -190 grains. - -Then 262-240,5 = 21,5, the quantity of water. - -And 262 grains of fibrous crystalized nitrate of ammoniac, contain 190 -grains true acid, 50,5 ammoniac, and 21,5 water. And 100 parts contain -72,5 acid. 19,3 ammoniac, and 8,2 water. - -In proportion as the temperature employed for the evaporation of -nitro-ammoniacal solutions, is above or below 212°, so in proportion -does the salt produced contain more or less water than the fibrous -nitrate. But whatever may have been the temperature of evaporation, the -acid and alkali appear always to be in the same proportions to each -other. - -Of the salts containing different quantities of water, two varieties -must be particularly noticed. The prismatic nitrate of ammoniac, -produced at the common temperatures of the atmosphere, and containing -its full quantity of water of crystalisation; and the compact nitrate -of ammoniac, either amorphous, or composed of delicately needled -crystals, formed at 300°, and containing but little more water than -exists in nitric acid and ammoniac. - -To discover the composition of the prismatic nitrate of ammoniac, 200 -grains of fibrous salt were dissolved in the smallest possible quantity -of water, and evaporated in a temperature not exceeding 70°. The -greater part of the salt was composed of perfectly formed tetrahædral -prisms, terminated by tetrahædral pyramids. It had gained in weight -about 8,5 grains. - -Consequently 100 grains of prismatic nitrate of ammoniac may be -supposed to contain 69,5 acid, 18,4 ammoniac, and 12,1 water. - -To ascertain the composition of the compact nitrate of ammoniac, I -exposed in a deep porcelain cup, 400 grains of the fibrous salt, in a -temperature below 300°. It quickly became fluid, and slowly gave out -its water without any ebullition, or liberation of gas. When it was -become perfectly dry, it had lost 33 grains. I suspected, that in this -experiment some of the salt had been carried off with the water; to -determine this, I introduced into a small glass retort, 460 grains of -fibrous salt; it was kept at a heat below 320°, in communication with a -mercurial apparatus, in a regulated air-furnace, till it was perfectly -dry: it had lost 23 grains. No gas, except the common air of the retort -came over, and the fluid collected had but a faint taste of nitrate of -ammoniac. - -Though in this experiment I had removed all the fluid retained in the -neck of the retort, still a few drops remained in the head, and on -the sides, which I could not obtain. It was of importance to me to be -accurately acquainted with the composition of the compact salt, and for -that reason I compared these analytical experiments with a synthetical -one. - -I saturated 200 grains of solution of ammoniac, of,9056 with acid, -ascertained the specific gravity of the solution, evaporated it at -212°, and fused and dried it at about 300°-260°. It gave 246 grains -of salt, and a solution made of the same specific gravity as that -evaporated, indicated a loss of 9 grains. Consequently, 255 grains of -this salt contain 50,5 grains alkali, 100 grains acid, and 14,5 grains -water. - -We may then conclude, that 100 parts of compact nitrate of ammoniac -contain 74,5 acid, 19,8 alkali, and 5,7 water. - - -V. _Decomposition of Carbonate of Ammoniac by Nitric Acid._ - -In my first experiments on the production of nitrate of ammoniac, I -endeavoured to ascertain its composition by decompounding carbonate -of ammoniac by nitric acid; and in making for this purpose, the -analysis of carbonate of ammoniac, I discovered that there existed -many varieties of this salt, containing very different proportions of -carbonic acid, alkali, and water; the carbonic acid and water being -superabundant in it, in proportion as the temperature of its formation -was low, and the alkali in proportion as it was high: and not only -that a different salt was formed at every different temperature, but -likewise that the difference in them was so great, that the carbonate -of ammoniac formed at 300° contained more than 50 per cent alkali, -whilst that produced at 60° contained only 20.[73] - -I found 210 grains of carbonate of ammoniac, which from comparison with -other salts previously analised, I suspected to contain about 20 or -21 per cent alkali, saturated by 200 grains of nitric acid of 1,504. -But though the carbonate was dissolved in much water, still, from the -smell of the carbonic acid generated, I suspect that a small portion -of the nitric acid was dissolved, and carried off by it. The solution, -evaporated at about 200°, and afterwards exposed to a temperature below -300°, gave 232 grains of compact salt. But reasoning from the quantity -of acid in 200 grains of nitric acid of 1,504, it ought to have given -245. Consequently 13 were lost by evaporation; and this loss agrees -with that in the other experiments. - -[73] A particular account of the experiments from which these facts -were deduced, was printed in September, and will appear in the first -volume of the _Researches_. - - -VI. _Decomposition of Sulphate of Ammoniac by Nitre._ - -As a cheap mode of obtaining nitrate of ammoniac, Dr. BEDDOES proposed -to decompose nitre by sulphate of ammoniac, which is a well known -article of commerce. From synthesis of sulphate of ammoniac, compared -with analysis made in August 1799,[74] I concluded that 100 grains of -prismatic salt were composed of about 18 grains ammoniac, 44 acid, and -38 water; and supposing 100 grains of nitre to contain 50 acid, 100 -grains of sulphate of ammoniac will require for their decomposition 134 -grains of nitre, and form 90,9 grains of compact nitrate of ammoniac. - -[74] And which will be published, with an account of its perfect -decomposition at a high temperature, in the _Researches_. - -To ascertain if the sulphate of potash and nitrate of ammoniac could be -easily separated, I added to a heated saturated solution of sulphate of -ammoniac, pulverised nitre, till the decomposition was complete. After -this decomposition, the solution contained a slight excess of sulphuric -acid, which was combined with lime, and the whole set to evaporate at -a temperature below 250°. As soon as the sulphate of potash began to -crystalise, the solution was suffered to cool, and then poured off from -the crystalised salt, which appeared to contain no nitrate of ammoniac. -After a second evaporation and crystalisation, almost the whole of -the sulphate appeared to be deposited, and the solution of nitrate of -ammoniac was obtained nearly pure: it was evaporated at 212°, and gave -fibrous crystals. - - -VII. _Non-existence of Ammoniacal Nitrites._ - -I attempted in different modes to combine _nitrous_ acids with -ammoniac, so as to form the salts which have been supposed to exist, -and called _nitrites_ of ammoniac; but without success. - -I first decomposed a solution of carbonate of ammoniac by dilute olive -colored acid; but in this process, though no heat was generated, -yet all the nitrous gas appeared to be liberated with the carbonic -acid.[75] I then combined a small quantity of nitrous gas, with a -solution of nitrate of ammoniac. But after evaporating this solution -at 70°-80°, I could not detect the existence of nitrous gas in the -solid salt; it was given out during the evaporation and crystalisation, -and formed into nitrous acid by the oxygene of the atmosphere. I -likewise heated nitrate of ammoniac to different degrees, and partially -decomposed it, to ascertain if in any case the acid was phlogisticated -by heat: but in no experiment could I detect the existence of -_nitrous_ acid in the heated salt, when it had been previously -perfectly neutralised. - -[75] When nitrous gas exists in neutro-saline solutions, they are -always colored more or less intensely, from yellow to olive, in -proportion to the quantity combined with them. - -When nitrate of ammoniac, indeed, with excess of nitric acid, is -exposed to heat, the superabundant nitric acid becomes phlogisticated, -and is then liberated from the salt, which remains neutral.[76] - -[76] Hence a nitrate of ammoniac with excess of acid, when exposed to -heat, first becomes yellow, and then white. - -We may therefore conclude that nitrous gas has little or no affinity -for solid nitrate of ammoniac, and that no substance exists to which -the name _nitrite_ of ammoniac can with propriety be applied. - - -VIII. _Of the sources of error in Analysis._ - -To compare my synthesis of nitrate of ammoniac with analysis, I -endeavoured to separate the ammoniac and nitric acid from each other, -without decomposition. But in going through the analytical process, I -soon discovered that it was impossible to make it accurate, without -many collateral laborious experiments on the quantities of ammoniac -soluble in water at different temperatures. - -At a temperature above 212°, I decomposed, by caustic slacked lime, 50 -grains of compact nitrate of ammoniac in a retort communicating with -the mercurial airholder, the moisture in which had been previously -saturated with ammoniac. 22 cubic inches of gas were collected at 38°, -and from the loss of weight of the retort, it appeared that 13 grains -of solution of ammoniac in water, had been deposited by the gas. - -Now evidently, this solution must have contained much more alkali in -proportion to its water than that of 55°, otherwise the quantity of -ammoniac in 50 grains of salt would hardly equal 8 grains.[77] - -[77] The accounts given by different chemists of the composition of -nitrate of ammoniac, are extremely discordant; they have been chiefly -deduced from decompositions of carbonate of ammoniac (the varieties of -which have been heretofore unknown) by nitrous acids of unknown degrees -of nitration. Hence they are particularly erroneous with regard to the -alkaline part. Wenzel supposes it to be 32 per cent, and Kirwan 24. -_Addit. Observ._ pag. 120. - - -IX. _Of the loss of Solutions of Nitrate of Ammoniac during -evaporation._ - -The most concentrated solution of nitrate of ammoniac capable of -existing at 60°, is of specific gravity 1,304, and contains 33 water, -and 67 fibrous salt, per cent. When this solution is evaporated at -temperatures between 60° and 100, the salt is increased in weight by -the addition of water of crystalisation, and no portion of it is lost. - -During the evaporation of solutions of specific gravity 1,146 and 1,15, -at temperatures below 120°, I have never detected any loss of salt. -When the temperature of evaporation is 212°, the loss is generally from -3 to 4 grains per cent; and when from 230° to the standard of their -ebullition, from 4 to 6 grains. - -In proportion as solutions are more diluted, their loss in evaporation -at equal temperatures is greater. - - -DIVISION III. - - _Decomposition of NITRATE of AMMONIAC: preparation of - RESPIRABLE NITROUS OXIDE; its ANALYSIS._ - - -I. _Of the heat required for the decomposition of NITRATE of AMMONIAC._ - -The decomposition of nitrate of ammoniac has been supposed by -Cornette[78] to take place at temperatures below 212°, and its -sublimation at 234°. - -Kirwan, from the non-coincidence in the accounts of its composition, -has imagined that it is partially decomposable, even by a heat of -80°.[79] - -[78] Mem. Par. 1783. See Irish Trans. vol. 4. - -[79] Addit. Obs. pag. 120. - -To ascertain the changes effected by increase of temperature in this -salt, a glass retort was provided, tubulated for the purpose of -introducing the bulb of a thermometer. After it had been made to -communicate with the mercurial airholder, and placed in a furnace, -the heat of which could be easily regulated, the thermometer was -introduced, and the retort filled with the salt, and carefully luted; -so that the appearances produced by different temperatures could be -accurately observed, and the products evolved obtained. - -From a number of experiments made in this manner on different salts, -the following conclusions were drawn. - -1st. Compact, or dry nitrate of ammoniac, undergoes little or no change -at temperatures below 260°. - -2dly. At temperatures between 275° and 300°, it slowly sublimes, -without decomposition, or without becoming fluid. - -3dly. At 320° it becomes fluid, decomposes, and still slowly sublimes; -it neither assuming, or continuing in, the fluid state, without -decomposition. - -4thly. At temperatures between 340° and 480°, it decomposes rapidly. - -5thly. The prismatic and fibrous nitrates of ammoniac become fluid at -temperatures below 300°, and undergo ebullition at temperatures between -360° and 400°, without decomposition. - -6thly. They are capable of being heated to 430° without decomposition, -or sublimation, till a certain quantity of their water is evaporated. - -7thly. At temperatures above 450° they undergo decomposition, without -previously losing their water of crystalisation. - - -II. _Decomposition of Nitrate of Ammoniac; production of respirable -Nitrous Oxide; its properties._ - -200 grains of compact nitrate of ammoniac were introduced into a -glass retort, and decomposed slowly by the heat of a spirit lamp. -The first portions of the gas that came over were rejected, and the -last received in jars containing mercury. No luminous appearance was -perceived in the retort during the process, and almost the whole of the -salt was resolved into fluid and gas. The fluid had a faint acid taste, -and contained some undecompounded nitrate. The gas collected exhibited -the following properties.— - -_a._ A candle burnt in it with a brilliant flame, and crackling noise. -Before its extinction, the white inner flame became surrounded with an -exterior blue one. - -_b._ Phosphorus introduced into it in a state of inflammation, burnt -with infinitely greater vividness than before. - -_c._ Sulphur introduced into it when burning with a feeble blue flame, -was instantly extinguished; but when in a state of active inflammation -(that is, forming sulphuric acid) it burnt with a beautiful and vivid -rose-colored flame. - -_d._ Inflamed charcoal, deprived of hydrogene, introduced into it, -burnt with much greater vividness than in the atmosphere. - -_e._ To some fine twisted iron wire a small piece of cork was affixed: -this was inflamed, and the whole introduced into a jar of the air. The -iron burned with great vividness, and threw out bright sparks as in -oxygene. - -_f._ 30 measures of it exposed to water previously boiled, was rapidly -absorbed; when the diminution was complete, rather more than a measure -remained. - -_g._ Pure water saturated with it, gave it out again on ebullition, and -the gas thus produced retained all its former properties. - -_h._ It was absorbed by red cabbage juice; but no alteration of color -took place. - -_i._ Its taste was distinctly sweet, and its odor slight, but agreeable. - -_j._ It underwent no diminution when mingled with oxygene or nitrous -gas. - -Such were the obvious properties of the NITROUS OXIDE, or the gas -produced by the decomposition of nitrate of ammoniac in a temperature -not exceeding 440°. Other properties of it will be hereafter -demonstrated, and its affinities fully investigated. - - -III. _Of the gas remaining after the absorption of Nitrous Oxide by -Water._ - -In exposing nitrous oxide at different times to rain or spring water, -and water that had been lately boiled, I found that the gas remaining -after the absorption was always least when boiled water was employed, -though from the mode of production of the nitrous oxide, I had reason -to believe that its composition was generally the same. - -This circumstance induced me to suppose that some of the residuum -might be gas previously contained in the water, and liberated from -it in consequence of the stronger affinity of that fluid for nitrous -oxide. But the greater part of it, I conjectured to consist of -nitrogene produced in consequence of a complete decomposition of part -of the acid, by the hydrogene. It was in endeavoring to ascertain the -relative purity of nitrous oxide produced at different periods of the -process of the decomposition of nitrate of ammoniac, that I discovered -the true reason of the appearance of residual gas. - -I decomposed some pure nitrate of ammoniac in a small glass retort; -and after suffering the first portions to escape with the common air, -I caught the remainder in three separate vessels standing in the same -trough, filled with water that had been long boiled, and which at -the time of the experiment was so warm that I could scarcely bear my -hands in it. The different quantities collected gave the same intense -brilliancy to the flame of a taper. - -26 measures of each of them were separately inserted into 3 graduated -cylinders, of nearly the same capacity, over the same boiled water. -As the water cooled, the gas was absorbed by agitation. When the -diminution was complete, the residuum in each cylinder filled, as -nearly as possible, the same space; about two thirds of a measure. - -To each of the residuums I added two measures of nitrous gas; they gave -copious red vapor, and after the condensation filled a space rather -less than two measures. - -Hence the residual gas contained more oxygene than common air. - -I now introduced 26 measures of gas from one of the vessels into a -cylinder filled with unboiled spring water of the same kind.[80] After -the absorption was complete, near two measures remained. These added to -two measures of nitrous air, diminished to 2,5 nearly. - -[80] Two measures of air dispelled from this water by boiling, mingled -with 2 of nitrous gas, diminished to 2,4 nearly. - -These experiments induced me to believe that the residual gas was not -produced in the decomposition of nitrate of ammoniac, but that it was -wholly liberated from the water. - -To ascertain this point with precision, I distilled a small quantity -of the same kind of water, which had been near an hour in ebullition, -into a graduated cylinder containing mercury. To this I introduced -about one third of its bulk, i. e. 12 measures of nitrous oxide, which -had been carefully generated in the mercurial apparatus. After the -absorption, a small globule of gas only remained, which could hardly -have equalled one fourth of a measure. On admitting to this globule a -minute quantity of nitrous gas, an evident diminution took place. - -Though this experiment proved that in proportion as the water was free -from air, the residuum was less, and though there was no reason to -suppose that the ebullition and distillation had freed the water from -the whole of the air it had held in solution, still I considered a -decisive experiment wanting to determine whether nitrous oxide was the -only gas produced in the slow decomposition of nitrate of ammoniac, or -whether a minute quantity of oxygene was not likewise evolved. - -I received the middle part of the product of a decomposition of nitrate -of ammoniac, under a cylinder filled with dry mercury, and introduced -to it some strong solution of ammoniac. After the white cloud produced -by the combination of the ammoniacal vapor with the nitric acid -suspended in the nitrous oxide, had been completely precipitated, I -introduced a small quantity of nitrous gas. No white vapor was produced. - -Now if any gas combinable with nitrous gas had existed in the cylinder, -the quantity of nitrous acid produced, however small, would have -been rendered perceptible by the ammoniacal fumes; for when a minute -globule of common air was admitted into the cylinder, white clouds were -instantly perceptible. - -It seems therefore reasonable to conclude, - -1. That the residual gas of nitrous oxide, is air previously contained -in the water, (which in no case can be perfectly freed from it by -ebullition), and liberated by the stronger attraction of that fluid for -nitrous oxide. - -2. That nitrate of ammoniac, at temperatures below 440°, is -decompounded into pure nitrous oxide, and fluid. - -3. That in ascertaining the purity of nitrous oxide from its absorption -by water, corrections ought to be made for the quantity of gas -dispelled from the water. This quantity in common water distilled -under mercury being about ¹/₅₀; in water simply boiled, and used when -hot, about ¹/₃₆; and in common spring water, ¹/₁₂. - - -IV. _Specific gravity of Nitrous Oxide._ - -To understand accurately the changes taking place during the -decomposition of nitrate of ammoniac, we must be acquainted with the -specific gravity and composition of nitrous oxide. - -90 cubic inches of it, containing about ¹/₃₅ common air, introduced -from the mercurial airholder into an exhausted globe, increased it in -weight 44,75 grains; thermometer being 51°, and atmospheric pressure -30,7. - -106 cubic inches, of similar composition, weighed in like manner, -gave at the same temperature and pressure nearly 52,25 grains; and in -another experiment, when the thermometer was 41°, 53 grains. - -So that accounting for the small quantity of common air contained in -the gases weighed, we may conclude, that 100 cubic inches of pure -nitrous oxide weigh 50,1 grains at temperature 50°, and atmospheric -pressure 30,7. - -I was a little surprised at this great specific gravity, particularly -as I had expected, from Dr. Priestley’s observations, to find it less -heavy than atmospherical air. This philosopher supposed, from some -appearances produced by the mixture of it with aëriform ammoniac, that -it was even of less specific gravity than that gas.[81] - -[81] Experiments and Observations, vol. 2, pag. 89. Last Edition. - - -V. _Analysis of Nitrous Oxide._ - -The nitrous oxide may be analised, either by charcoal or hydrogene; -during the combustion of other bodies in it, small portions of nitrous -acid are generally formed, as will be fully explained hereafter. - -The gas that I employed was generated from compact nitrate of ammoniac, -and was in its highest state of purity, as it left a residuum of ¹/₃₈ -only, when absorbed by boiled water. - -10 cubic inches of it were inserted into a jar graduated to,1 cubic -inches, containing dry mercury. Through this mercury a piece of -charcoal which had been deprived of its hydrogene by long exposure -to heat, weighing about a grain, was introduced, while yet warm. No -perceptible absorption of the gas took place.[82] - -[82] A minute quantity, however, must have been absorbed, and given out -again when the charcoal was heated. - -Thermometer being 46°, the focus of a lens was thrown on the charcoal, -which instantly took fire, and burnt vividly for about a minute, the -gas being increased in volume. After the vivid combustion had ceased, -the focus was again thrown on the charcoal; it continued to burn for -near ten minutes, when the process stopped. - -The gas, when the original pressure and temperature were restored, -filled a space equal to 12,5 cubic inches. - -On introducing to it a small quantity of strong solution of -ammoniac[83], white vapor was instantly perceived, and after a short -time the reduction was to about 10,1 cubic inches; so that apparently, -2,4 cubic inches of carbonic acid had been formed. The 10,1 cubic -inches of gas remaining were exposed to water which had been long in -ebullition, and which was introduced whilst boiling, under mercury. -After the absorption of the nitrous oxide by the water, the gas -remaining was equal to 5,3. - -[83] Strong solution of ammoniac has no attraction for nitrous oxide. - -But on combining a cubic inch of pure nitrous oxide with some of the -same water, which had been received under mercury in a separate vessel, -nearly ¹/₂₂ remained. Consequently we may conclude, that 5,1 of a gas -unabsorbable by water, was produced in the combustion. - -This gas extinguished flame, gave no diminution with oxygene, and the -slightest possible with nitrous gas. When an electric spark was passed -through it, mingled with oxygene; no inflammation, or _perceptible_ -diminution took place.[84] We may consequently conclude that it was -nitrogene, mingled with a minute portion of common air, expelled from -the water. - -[84] The gas was examined by those tests in order to prove that no -water had been decomposed. - -The charcoal was diminished in bulk to one half nearly, but the loss of -weight could not be ascertained, as its pores were filled with mercury. - -Now 5 cubic inches of nitrous oxide were absorbed by the water, -consequently 5 were decompounded by the charcoal; and these produced -5,1 cubic inches of nitrogene; and by giving their oxygene to the -charcoal, apparently 2,4 of carbonic acid. - -But 5 cubic inches of nitrous oxide weigh 2,5 grains, and 5,1 cubic -inches of nitrogene 1,55; then 2,5-1,55 =,95. - -So that reasoning from the relative specific gravities of nitrogene and -nitrous oxide, 2,5 grains of the last are composed of 1,55 nitrogene, -and,95 oxygene. - -But from many experiments made on the specific gravity of carbonic -acid, in August, 1799, I concluded that 100 cubic inches of it weighed -47,5 grains, thermometer being 60,1°, and barometer 29,5. Consequently, -making the necessary corrections, 2,4 cubic inches of it weigh -1,14 grains; and on Lavoisier’s and Guyton’s[85] estimation of its -composition, these 1,13 grains contain 8,2 of oxygene. - -[85] See the curious paper of this excellent philosopher, on the -combustion of the diamond, in which he proves that charcoal is, in -fact, oxide of diamond. Annales de Chimie, xxxi. - -So that, drawing conclusions from the quantity of carbonic acid formed -in this experiment, 2,5 grains of nitrous oxide will be composed of,82 -oxygene, and 1,68 nitrogene. - -The difference between these estimations is considerable, and yet not -more than might have been expected, if we consider the probable sources -of error in the experiment. - -1. It is likely that variable minute quantities of hydrogene remain -combined with charcoal, even after it has been long exposed to a red -heat. - -2. It is probable that the nitrogene and carbonic acid produced were -capable of dissolving more water than that held in solution by the -nitrous oxide; and if so, they were more condensed than if saturated -with moisture, and hence the quantity of carbonic acid under-rated. - -We may consequently suppose the estimation founded on the quantity of -nitrogene evolved, most correct; and making a small allowance for the -difference, conclude, that 100 grains of nitrous oxide are composed of -about 37 oxygene, and 63 nitrogene; existing in a much more condensed -state than when in their simple forms. - -The tolerable accuracy of this statement will be hereafter demonstrated -by a number of experiments on the combustion of different bodies in -nitrous oxide, detailed in Research II. - - -VI. _Minute examination of the decomposition of Nitrate of Ammoniac._ - -Into a retort weighing 413,75 grains, and of the capacity of 7,5 -cubic inches, 100 grains of pulverised compact nitrate of ammoniac -were introduced. To the neck of this retort was adapted a recipient, -weighing 711 grains, tubulated for the purpose of communicating with -the mercurial airholder, and of the capacity of 8,3 cubic inches. - -Temperature being 50° and atmospheric pressure 30,6, the recipient -was inserted into a vessel of cold water, and made to communicate -with the airholder. The heat of a spirit lamp was then slowly applied -to the retort: the salt quickly began to decompose, and to liquify. -The temperature was so regulated, as to keep up an equable and slow -decomposition. - -During this decomposition, no luminous appearance was perceived in the -retort; the gas that came into the airholder was very little clouded, -and much water condensed in the receiver. - -After the process was finished, the communication between the mercurial -airholder and the recipient was preserved till the common temperature -was restored to the retort. - -The volume of the gas in the cylinder was 85,5 cubic inches. The -absolute quantity of nitrous oxide in those 85,5 cubic inches, it was -difficult to ascertain with great nicety, on account of the common air -previously contained in the vessels. - -45 measures of it, exposed to well boiled water, diminished by -agitation to 8 measures. So that reasoning from the quantity of air, -which should have been expelled from the water by the nitrous oxide, we -may conclude that the 85,5 cubic inches were nearly pure. - -The retort now weighed 419,25 grains, consequently 5,5 grains of salt -remained in it. This salt was chiefly collected about the lower part -of the neck, and contained rather more water than the compact nitrate, -as in some places it was crystalised. - -The recipient with the fluid it contained, weighed 759 grains. It had -consequently gained in weight 48 grains. - -Now the 85,5 cubic inches of nitrous oxide produced, weigh about 42,5 -grains; and this added to 48 and 5,5, = 96 grains; so that about 4 -grains of salt and fluid were lost, probably by being carried over and -deposited by the gas.[86] - -[86] This was actually the case; for on examining the conducting tube -the day after the experiment, some minute crystals of prismatic nitrate -of ammoniac were perceived in it. - -As much of the fluid as could be taken out of the recipient, weighed -46 grains, and held in solution much nitrate of ammoniac with -superabundance of acid. This acid required for its saturation, 3⅛ of -carbonate of ammoniac (containing, as well as I could guess), about 20 -per cent alkali. - -The whole solution evaporated, gave 18 grains of compact nitrate of -ammoniac. But reasoning from the quantity of carbonate of ammoniac -employed, the free nitric acid was equal to 2,75 grains, and this must -have formed 3,56 grains of salt. Consequently the salt pre-existing in -the solution was about 14,44 grains. - -But besides the fluid taken out of the recipient, 2 grains remained in -it: let us suppose this, and the 4 grains lost, to contain 2 of salt, -and,6 of free acid. - -Then the undecompounded - - salt is 5,5 + 14,4 + 2 = 21,9 - The free acid 2,75 + ,6 = 3,35 - Gas 42,5 - Water 32,25 - —————— - 100 - -Now about 78,1 grains of salt were decompounded, and formed into 42,5 -grains of gas, 3,35 grains acid, and 32,25 grains water. - -But there is every reason to suppose, that in this process, when the -hydrogene of the ammoniac combines with a portion of the oxygene of -the nitric acid to form water, and the nitrogene enters into union -with the nitrogene and remaining oxygene of the nitric acid, to form -nitrous oxide; that water pre-existing in nitric acid and ammoniac, -such as they existed in the aëriform state, is deposited with the water -produced by the new arrangement, and not wholly combined with the -nitrous oxide formed. Hence it is impossible to determine with great -exactness, the quantity of water which was absolutely formed in this -experiment. - -78,1 grains of salt are composed of 15,4 alkali, 58 acid, and 4,7 water. - -And reasoning from the different affinities of water for nitric acid, -ammoniac, and nitrous oxide, it is probable that ammoniac, in its -decomposition, divides its water in such a ratio, between the nitrogene -furnished to the nitrous oxide, and the hydrogene entering into union -with the oxygene of the nitric acid, as to enable us to assume, that -the hydrogene requires for its saturation nearly the same quantity of -oxygene as when in the aëriform state; or that it certainly cannot -require less. - -But 15,4 alkali contain 3,08 hydrogene, and 12,32 nitrogene;[87] and -3,08 hydrogene require 17,4 of oxygene to form 20,48 of water. - -[87] Owing part of their weight to an unknown quantity of water. - -Now 32,5 grains of water existed before the experiment; 4,7 grains of -water were contained by the salt decomposed, and 32,5-4,7 = 27,8: and -27,8-20,48, the quantity generated, = 7,52, the quantity existing in -the nitric acid. - -But the nitric acid decomposed is 58ᵍ-3,35 = to 54,7; and 54,7-7,5 -= 47,2, which entered into new combinations. These 47,2 consist of -33,2 oxygene, and 14, nitrogene. And 33,2-17,4, the quantity employed -to form the water, = 15,8, which combined with 14,0, nitrogene of -the nitric acid, and 12,32 of that of the ammoniac, to form 42,12 of -nitrous oxide. And on this estimation, 100 parts of nitrous oxide -would contain 37,6 oxygene, and 62,4 nitrogene; a computation much -nearer the results of the analysis than could have been expected, -particularly as so many unavoidable sources of error existed in the -process. - -The experiment that I have detailed is the most accurate of four, made -on the same quantity of salt. The others were carried on at rather -higher temperatures, in consequence of which, more water and salt were -sublimed with the gas. - -To Berthollet, we owe the discovery of the products evolved during the -slow decomposition of nitrate of ammoniac; but as this philosopher -in his examination of this process, chiefly designed to prove the -existence of hydrogene in ammoniac, he did not ascertain the quantity -of gas produced, or minutely examine its properties; from two of -them, its absorption by water and its capability of supporting the -vivid combustion of a taper, he inferred its identity with the -dephlogisticated nitrous gas of Priestley, and concluded that it was -nitrous gas with excess of pure air.[88] - -[88] Mem. de Paris. 1785, and Journal de Physique, 1786, page 175. - - -VII. _Of the heat produced during the decomposition of nitrate of -ammoniac._ - -To ascertain whether the temperature of nitrate of ammoniac was -increased or diminished after it had been raised to the point essential -to its decomposition, during the evolution of nitrous oxide and water; -that is, in common language, whether heat was generated or absorbed -in the process; I introduced a thermometer into about 1500 grains of -fibrous nitrate of ammoniac, rendered liquid in a deep porcelain cup. -During the whole of the evaporation, the temperature was about 380°, -the fire being carefully regulated. - -As soon as the decomposition took place, the thermometer began to rise; -in less than a quarter of a minute it was 410°, in two minutes it was -460°. - -The cup was removed from the fire; the decomposition still went on -rapidly, and for about a minute the thermometer was stationary. It -then gradually and slowly fell; in three minutes it was 440°, in -five minutes 420°, in seven minutes 405° in nine minutes 360° and in -thirteen minutes 307°, when the decomposition had nearly ceased, and -the salt began to solidify. - -From this experiment, it is evident that an increase of temperature -is produced by the decomposition of nitrate of ammoniac: though the -capacity of water and nitrous oxide for heat, supposing the truth of -the common doctrine, and reasoning from analogy, must be considerably -greater than that of the salt. - - -VIII. _Of the decomposition of Nitrate of Ammoniac at high -temperatures, and production of Nitrous gas, Nitrogene, Nitrous Acid, -and Water._ - -At an early period of my investigation relating to the nitrous oxide, -I discovered that when a heat above 600° was applied to nitrate of -ammoniac, so that a vivid luminous appearance was produced in the -retort, certain portions of nitrous gas, and nitrogene, were evolved -with the nitrous oxide. But I was for some time ignorant of the -precise nature of this decomposition, and doubtful with regard to -the possibility of effecting it in such a manner as to prevent the -production of nitrous oxide altogether. - -I first attempted to decompose nitrate of ammoniac at high -temperatures, by introducing it into a well coated green glass retort, -having a wide neck, communicating with the pneumatic apparatus, and -strongly heated in an air-furnace. But though in this process a -detonation always took place, and much light was produced, yet still -the greater portion of the gas generated was nitrous oxide; the nitrous -gas and nitrogene never amounting to more than one third of the whole. - -After breaking many retorts by explosions, without gaining any accurate -results, I employed a porcelain tube, curved so as to be capable of -introduction into the pneumatic apparatus, and closed at one end. - -The closed end was heated red, nitrate of ammoniac introduced into it, -and all the latter portions of gas produced in the explosion, received -in the pneumatic apparatus, filled with warm water. - -Three explosions were required to fill a jar of the capacity of 20 -cubic inches. The gas produced in the first, when it came over, was -transparent and dark orange, similar in its appearance to the nitrous -acid gas produced in the first experiment; but it speedily became white -and clouded, whilst a slight diminution of volume took place. - -When the second portion was generated and mingled with the clouded -gas, it again became transparent and yellow for a short time, and then -assumed the same appearance as before. - -The water in the trough, after this experiment, had an acid taste, and -quickly reddened cabbage juice rendered green by an alkali. - -6 cubic inches of the gas produced were exposed to boiled water, but -little or no absorption took place. Hence, evidently, it contained no -nitrous oxide. - -They were then exposed to solution of sulphate of iron: the solution -quickly became dark colored, and an absorption of 1,6 took place on -agitation.[89] - -[89] The absorption of nitrous gas by sulphate of iron, &c. will be -treated of in the next division. - -The gas remaining instantly extinguished the taper, and was -consequently nitrogene. - -This experiment was repeated, with nearly the same results. - -We may then conclude, that at high temperatures, nitrate of ammoniac is -wholly resolved into water, nitrous acid, nitrous gas, and nitrogene; -whilst a vivid luminous appearance is produced. - -The transparency and orange color produced in the gas that had been -clouded, by new portions of it, doubtless arose from the solution of -the nitric acid and water forming the cloud, in the heated nitrous -vapor produced, so as to constitute an aëriform triple compound; -whilst the cloudiness and absorption subsequent were produced by the -diminished temperature, which destroyed the ternary combination, and -separated the nitrous acid and water from the nitrous gas. - -From the rapidity with which the deflagration of nitrate of ammoniac -proceeds, and from the immense quantity of light produced, it is -reasonable to suppose that a very great increase of temperature takes -place. The tube in which the decomposition has been effected, is always -ignited after the process. - - -IX. _Speculations on the decompositions of Nitrate of Ammoniac._ - -All the phænomena of chemistry concur in proving, that the affinity of -one body, A, for another, B, is not destroyed by its combination with a -third, C, but only modified; either by condensation, or expansion, or -by the attraction of C for B. - -On this principle, the attraction of compound bodies for each other -must be resolved into the reciprocal attractions of their constituents, -and consequently the changes produced in them by variations of -temperature explained, from the alterations produced in the attractions -of those constituents. - -Thus in nitrate of ammoniac, four affinities may be supposed to exist: - - 1. That of hydrogene for nitrogene, producing ammoniac. - - 2. That of oxygene for nitrous gas, producing nitric acid. - - 3. That of the hydrogene of ammoniac for the oxygene - of nitric acid. - - 4. That of the nitrogene of ammoniac for the nitrous gas - of nitric acid. - -At temperatures below 300°, the salt, from the equilibrium between -these affinities, preserves its existence. - -Now when its temperature is raised to 400°, the attractions of -hydrogene for nitrogene,[90] and of nitrous gas for oxygene,[91] are -diminished; whilst the attraction of hydrogene for oxygene[92] is -increased; and perhaps that of nitrogene for nitrous gas. - -[90] As is evident from the decomposition of ammoniac by heat. - -[91] Nitric acid is phlogisticated by heat, as appears from Dr. -Priestley’s experiments. Vol. 3, p. 26. - -[92] As is evident from the increase of temperature required for the -formation of water. - -Hence the former equilibrium of affinity is destroyed, and a new one -produced. - -The hydrogene of the ammoniac combines with the oxygene of the nitric -acid to generate water; and the nitrogene of the ammoniac enters into -combination with the nitrous gas to form nitrous oxide: and the water -and nitrous oxide produced, most probably exist in binary combination -in the aëriform state, at the temperature of the decomposition. - -But when a heat above 800° is applied to nitrate of ammoniac, the -attractions of nitrogene and hydrogene for each other, and of -oxygene for nitrous gas,[93] are still more diminished; whilst that -of nitrogene for nitrous gas is destroyed, and that of hydrogene -for oxygene increased to a great extent: likewise a new attraction -takes place; that of nitrous gas for nitric acid, to form nitrous -vapor.[94] Hence a new arrangement of principles is rapidly produced; -the nitrogene of ammoniac having no affinity for any of the single -principles at this temperature, enters into no binary compound: the -oxygene of the nitric acid forms water with the hydrogene, and the -nitrous gas combines with the nitric acid to form nitrous vapor. All -these substances most probably exist in combination at the temperature -of their production; and at a lower temperature, assume the forms of -nitrous acid, nitrous gas, nitrogene, and water. - -[93] For ammoniac and nitrous oxide are both decomposed at the red -heat, and oxygene given out from nitric acid when it is passed through -a heated tube. - -[94] Whenever nitrous acid is produced at high temperatures, it is -always highly phlogisticated, provided it has not been long in contact -with oxygene. When Dr. Priestley passed nitric acid through a tube -heated red, he procured much oxygene, and phlogisticated acid; and the -water in the apparatus employed was fully impregnated with nitrous air. -Hence it would appear, that heat diminishes the attraction between -oxygene and nitrous gas, and increases the affinity of nitrous gas for -nitrous acid. Mr. JAMES THOMSON, whose theory of the Nitrous Acid I -have already mentioned, from some experiments on the phlogistication -of Nitric Acid by heat, which he has communicated to me, concludes -with great justness, that a portion of the acid is always completely -decomposed in this process: the oxygene liberated, and the nitrous gas -combined with the remaining acid. - -I have avoided entering into any discussions concerning the light -and heat produced in this process; because these phænomena cannot be -reasoned upon as isolated facts, and their relation to general theory -will be treated of hereafter. - - -X. _On the preparation of Nitrous Oxide for experiments on Respiration._ - -When compact nitrate of ammoniac is slowly decomposed, the nitrous -oxide produced is almost immediately fit for respiration; but as one -part of the salt begins to decompose before the other is rendered -fluid, a considerable loss is produced by sublimation. - -For the production of large quantities of nitrous oxide, fibrous -nitrate of ammoniac should be employed. This salt undergoes no -decomposition till the greater part of its water is evaporated, and in -consequence at the commencement of that process, is uniformly heated. - -The gas produced from fibrous nitrate, must be suffered to rest at -least for an hour after its generation. At the end of this time it is -generally fit for respiration. If examined before, it will be found -to contain more or less of a white vapor, which has a disagreeable -acidulous taste, and strongly irritates the fauces and lungs. This -vapor, most probably, consists of acid nitrate of ammoniac and water, -which were dissolved by the gas at the temperature of its production, -and afterwards slowly precipitated. - -It is found in less quantity when compact nitrate is employed, -because more salt is sublimed in this process, which being rapidly -precipitated, carries with it the acid and water. - -Whatever salt is employed, the last portions of gas produced, generally -contain less vapor, and may in consequence be respired sooner than the -first. - -The nitrate of ammoniac should never be decomposed in a metallic -vessel,[95] nor the gas produced suffered to come in contact with -any metallic surface; for in this case the free nitric acid will be -decomposed, and in consequence, a certain quantity of nitrous gas -produced. - -[95] Except it be gold or platina. - -The apparatus that has been generally employed in the medical pneumatic -institution, for the production of nitrous oxide, consists - - 1. Of a glass retort, of the capacity of two or three quarts, - orificed at the top, and furnished with a ground stopper. - - 2. Of a glass tube, conical for the purpose of receiving the - neck of the retort; about ,4 inches wide in the narrowest - part, 4 feet long, curved at the extremity, so as to be - capable of introduction into an airholder, and inclosed by - tin plate to preserve it from injury. - - 3. Of airholders of Mr. Watt’s invention, filled with water - saturated with nitrous oxide. - - 4. Of a common air-furnace, provided with dampers for the - regulation of the heat. - -The retort, after the insertion of the salt, is connected with the -tube, carefully luted, and exposed to the heat of the furnace, on a -convenient stand. The temperature is never suffered to be above 500°. -After the decomposition has proceeded for about a minute, so that the -gas evolved from the tube enlarges the flame of a taper, the curved end -is inserted into the airholder, and the nitrous oxide preserved. - -The water thrown out of the airholders in consequence of the -introduction of the gas, is preserved in a vessel adapted for the -purpose, and employed to fill them again; for if common water was to -be employed in every experiment, a great loss of gas would be produced -from absorption. - -A pound of fibrous nitrate of ammoniac, decomposed at a heat not above -500°, produces nearly 5 cubic feet of gas; whilst from a pound of -compact nitrate of ammoniac, rarely more than 4,25 cubic feet can be -collected. - -For the production of nitrous oxide in quantities not exceeding 20 -quarts, a mode still more simple than that I have just described may be -employed. The salt may be decomposed by the heat of an argands lamp, or -a common fire, in a tubulated glass retort, of 20 or 30 cubic inches in -capacity, furnished with a long neck, curved at the extremity; and the -gas received in small airholders. - -Thus, if the pleasurable effects, or medical properties of the nitrous -oxide, should ever make it an article of general request, it may be -procured with much less time, labor, and expence,[96] than most of the -luxuries, or even necessaries, of life. - -[96] A pound of nitrate of ammoniac costs about 5s. 10d. This pound, -properly decomposed, produces rather more than 34 moderate doses of -air; so that the expence of a dose is about 2d. What fluid stimulus can -be procured at so cheap a rate? - - -DIVISION IV. - - _EXPERIMENTS and OBSERVATIONS on the COMPOSITION of - NITROUS GAS, and on its ABSORPTION by different - bodies._ - - -I. _Preliminaries._ - -In my account of the composition of nitric acid, in Division I. I gave -an estimation of the quantities of oxygene and nitrogene combined -in nitrous gas: I shall now detail the experiments on which that -estimation is founded. - -At an early period of my researches relating to nitrous oxide, from -the observation of the phænomena taking place during the production of -this substance, I had concluded, that the common opinion with regard -to the composition of nitrous gas, was very distant from the truth. -I had indeed analysed nitrous gas, by converting it into nitrous -oxide, before I attempted to ascertain its composition by immediately -separating the constituent principles from each other: and my first -hopes of the possibility of effecting this, were derived from Dr. -Priestley’s experiments on the combustion of pyrophorus in nitrous gas, -and on the changes effected in it, by heated iron and charcoal. - -This great philosopher found, that pyrophorus placed in contact with -nitrous gas, burnt with great vividness, whilst the gas was diminished -in volume to about one half, which generally consisted of nitrogene -and nitrous oxide. He likewise found, iron heated by a lens in nitrous -gas, increased in weight, whilst the gas was diminished about ½, and -converted into nitrogene.[97] - -He heated common charcoal, and charcoal of copper,[98] in nitrous gas -by a lens. When common charcoal was employed, the gas was neither -increased or diminished in bulk, but wholly converted into nitrogene; -when charcoal of copper was used, the volume was a little increased, -and the gas remaining consisted of ⁵/₇ nitrogene, and ²/₇ carbonic acid. - -[97] Experiments and Observations, vol. II. pag. 50. Last Edition. - -[98] That is, charcoal produced by the decomposition of spirits of -wine. Vol. II. pag. 39. - -In his experiments on the iron and pyrophyrus, the nitrous gas -was evidently decomposed. From the great quantity of nitrogene -produced in those on the charcoal, it seems likely that both the -common charcoal,[99] and the charcoal of copper employed contained -atmospherical air, which being dispelled by the heat of the lens, -was decomposed by the nitrous gas: indeed, till I made the following -experiment, I suspected that the carbonic acid produced, when the -charcoal of copper was employed, arose from a decomposition of the -nitrous acid, formed in this way. - -[99] Dr. Priestley says, “having heated iron in nitrous air, I -proceeded to heat in the same air, a piece of charcoal not long after -it had been subjected to a strong heat covered with sand. The sun -not shining immediately, after the charcoal was introduced into the -vessel of air, through the mercury by which it was confined, part -of the air was absorbed; but on heating the charcoal, the quantity -was increased. Having continued the progress as long as I thought -necessary, I examined the air and found it to be about as much as -the original quantity of nitrous air; but it was all phlogisticated -air extinguishing a candle and having no mixture of fixed air in -it.”—Experiments and Observations, Vol. II, page 39. - -I introduced a piece of well-burnt charcoal, which could hardly have -weighed the eighth of a grain, whilst red hot, under a cylinder filled -with mercury, and admitted to it half a cubic inch of nitrous gas. A -slight absorption took place. - -The sun being very bright, I kept the charcoal in the focus of a -small lens for near a quarter of an hour. At the end of this time -the gas occupied a space nearly as before the experiment, and a very -minute portion of the charcoal had been consumed. On introducing -into the cylinder a small quantity of solution of strontian, a white -precipitation was perceived, and the gas slowly diminished to about -three tenths of a cubic inch. To these three tenths a little common air -was admitted, when very slight red fumes were perceived. - -This experiment convinced me, that the attraction of charcoal for the -oxygene of nitrous gas, at high temperatures, was sufficiently strong -to effect a slow decomposition of it. - -To be more accurately acquainted with this decomposition, and to learn -the quantities of carbonic acid and nitrogene produced from a known -quantity of nitrous gas, I proceeded in the following manner. - - -II. _Analysis of Nitrous Gas by Charcoal._ - -A quantity of nitrous gas was procured in a water apparatus, from -the decomposition of nitrous acid by mercury. A portion of it was -transferred to the mercurial trough. After the mercury and the jar -had been dried by bibulous paper, 40 measures of this portion were -agitated in a solution of sulphate of iron. The gas remaining after -the absorption was complete, filled about a measure and half; so that -the nitrous gas contained nearly ¹/₂₆ nitrogene. - -Thermometer being 53°, a small piece of well-burnt charcoal, the -weight of which could hardly have equalled a quarter of a grain, -was introduced ignited, into a small cylinder filled with mercury, -graduated to,10 grain measures; to this, 16 measures, equal to 160 -grain m. of nitrous gas, were admitted. An absorption of about one -measure and half took place. When the focus of a lens was thrown on the -charcoal, a slight increase of the gas was produced, from the emission -of that which had been absorbed. - -After the process had been carried on for about a half an hour, the -charcoal evidently began to fume, and to consume very slowly, though no -alteration in the volume of the gas was observed. - -The sun not constantly shining, the progress of the experiment was now -and then stopped: but taking the whole time, the focus could not have -been applied to it for less than four hours. When the process was -finished, the gas was increased in bulk nearly three quarters of a -measure. - -A drop of water was introduced into the cylinder, by means of a small -glass tube, on the supposition that the carbonic acid, and nitrogene, -might be capable of holding in solution, more water than that contained -in the nitrous gas decomposed; but no alteration of volume took place. - -When 20 grain measures of solution of pale green[100] sulphate of iron -were introduced into the cylinder, they became rather yellower than -before, but not dark at the edges, as is always the case when nitrous -gas is present. On agitation, a diminution of nearly half a measure was -produced, doubtless from the absorption of some of the carbonic acid by -the solution. - -[100] That is, sulphate of iron containing oxide of iron, in the first -degree of oxygenation. - -A small quantity of caustic potash, much more than was sufficient to -decompose the sulphate of iron, was now introduced. A rapid diminution -took place, and the gas remaining filled about 8 measures. This gas was -agitated for some time over water, but no absorption took place. Two -measures of it were then transferred into a detonating cylinder with -two measures of oxygene. The electric spark was puffed through them, -but no diminution was produced. Hence it was nitrogene, mingled with no -ascertainable quantity of hydrogene: consequently little or no water -could have been decomposed in the process. - -Now supposing, for the greater ease of calculation, each of the -measures employed, cubic inches. - -16 of nitrous gas—¹/₂₆ = 15,4 were decomposed, and these weigh, making -the necessary corrections, 5,2; but 7,4 nitrogene were produced, and -these weigh about 2,2. So that reasoning from the relative specific -gravities of nitrous gas and nitrogene, 5,2 grains of nitrous gas will -be composed of 3 oxygene, and 2,2 nitrogene. - -But 8,7 of carbonic acid were produced, which weigh 4,1 grains, and -consist of 2,9 oxygene, and 1,2 charcoal.[101] Consequently, drawing -conclusions from the quantity of carbonic acid formed, 5,2 grains of -nitrous gas will consist of 2,9 oxygene, and 2,3 nitrogene. - -[101] That is, carbon, or oxide of diamond. - -The difference in these estimations is much less than could have been -expected; and taking the mean proportions, it would be inferred from -them, that 100 grains of nitrous gas, contain 56,5 oxygene, and 43,5 -nitrogene. - -I repeated this experiment with results not very different, except that -the increase of volume was rather greater, and that more unabsorbable -gas remained; which probably depended on the decomposition of a minute -quantity of water, that had adhered to the charcoal in passing through -the mercury. - -As nitrous gas is decomposable into nitrous acid, and nitrogene, by the -electric spark; it occurred to me, that a certain quantity of nitrous -acid might have been possibly produced, in the experiments on the -decomposition of nitrous gas, by the intensely ignited charcoal. To -ascertain this circumstance, I introduced into 12 measures of nitrous -gas, a small piece of charcoal which had been just reddened. The sun -being very bright, the focus of the lens was kept on it for rather more -than an hour and quarter. In the middle of the process it began to fume -and to sparkle, as if in combustion. In three quarters of an hour, the -gas was increased rather more than half a measure; but no alteration of -volume took place afterwards. - -The mercury was not white on the top as is usually the case when -nitrous acid is produced. On introducing into the cylinder a little -pale green sulphate of iron, and then adding prussiate of potash, a -white precipitate only was produced. Now, if the minutest quantity -of nitric acid had been formed, it would have been decomposed by the -pale green oxide of iron, and hence, a visible quantity of prussian -blue[102] produced, as will be fully explained hereafter. - -[102] That is, blue prussiate of iron. - - -III. _Analysis of Nitrous Gas by Pyrophorus._ - -I placed some newly made pyrophorus, about as much as would fill -a quarter of a cubic inch, in a jar filled with dry mercury, and -introduced to it, four cubic inches of nitrous gas, procured from -mercury and nitric acid. - -It instantly took fire and burnt with great vividness for some moments. - -After the combustion had ceased, the gas was diminished about three -quarters of a cubic inch. The remainder was not examined; for the -diminution appeared to go on for some time, after; in an half hour, -when it was compleat, it was to 2 cubic inches. A taper, introduced -into these, burnt with an enlarged flame, blue at the edges; from -whence it appeared, that they were composed of nitrogene and nitrous -oxide. - -I now introduced about half a cubic inch of pyrophorus to two cubic -inches of nitrous gas; the combustion took place, and the gas was -rapidly diminished to one half; and on suffering it to remain five -minutes to one third nearly; which extinguished flame. - -Suspecting that this great diminution was owing to the absorption of -some of the nitrogene formed, by the charcoal of the pyrophorus, I -carefully made a quantity of pyrophorus; employing more than two thirds -of alumn, to one third of sugar. - -To rather more than half of a cubic inch of this, two cubic inches of -nitrous gas, which contained about ¹/₄₀ nitrogene, were admitted. After -the combustion, the gas remaining, _apparently_ filled a space equal -to 1,2 cubic inches; but, as on account of the burnt pyrophyrus in the -jar, it was impossible to ascertain the volume with nicety, it was -carefully and wholly transferred into another jar. It filled a space -equal to 1,15 cubic inches nearly. - -When water was admitted to this gas no absorption took place. It -underwent no diminution with nitrous gas, and a taper plunged into it -was instantly extinguished. We may consequently conclude that it was -nitrogene. - -Now 2 cubic inches of nitrous gas weigh,686 grains, and 1,1 of -nitrogene—,05, the quantity previously contained in the gas = to 1,05, -3,19. Hence,686 of nitrous gas would be composed of,367 oxygene, and -,319 nitrogene; and 100 grains would contain 53,4 oxygene, and 46,6 -nitrogene. - - -IV. _Additional observations on the combustion of bodies in Nitrous -Gas, and on its Composition._ - -Though phosphorus may be fused, and even sublimed, in nitrous gas, -without producing the slightest luminous appearance,[103] yet when it -is introduced into it in a state of active inflammation, it burns -with almost as much vividness as in oxygene.[104] Hence it is evident, -that at the heat of ignition, phosphorus is capable of attracting the -oxygene from the nitrogene of nitrous gas. - -[103] No luminous appearance is produced when phosphorus is introduced -into _pure_ nitrous gas. It has been often observed, that phosphorus is -luminous in nitrous gas, that has not been long in contact with water -after its production. This phænomenon, I suspect, depends either on the -decomposition of the nitric acid held in solution by the nitrous gas; -or on the combination of the phosphorus with oxygene loosely adhering -to the binary aëriform compound of nitric acid and nitrous gas. I have -not yet examined if nitrous gas can be converted into nitrous oxide by -long exposure to heated phosphorus: it appears, however, very probable. - -[104] Perhaps this fact has been noticed before; I have not, however, -met with it in any chemical work. - -I attempted to analise nitrous gas, by introducing into a known -quantity of it, confined by mercury, phosphorus, in a vessel containing -a minute quantity of oxygene.[105] The phosphorus was inflamed with -an ignited iron wire, by which, at the moment of the combustion, the -vessel containing it was raised from the mercury into the nitrous gas. -But after making in this way, five of six unsuccessful experiments, I -desisted. When the communication between the vessels was made before -the oxygene was nearly combined with the phosphorus, nitrous acid -was formed, which instantly destroyed the combustion; when, on the -contrary, the phosphorus was suffered to consume almost the whole -of the oxygene, it was not sufficiently ignited when introduced, to -decompose the nitrous gas. - -[105] This mode of inflaming bodies in gases, not capable of supporting -combustion at low temperatures, will be particularly described -hereafter. - -In one experiment, indeed, the phosphorus burnt for a moment in the -nitrous gas; the diminution however was slight, and not more than ¼ of -it was decomposed. - -Sulphur, introduced in a state of vivid inflammation, into nitrous gas, -was instantly extinguished. - -I passed a strong electric shock through equal parts of hydrogene -and nitrous gas, confined by mercury in a detonating tube; but no -inflammation, or perceptible diminution, was produced. - -19,2 grain measures of hydrogene were fired by the electric shock, -with 10 of nitrous oxide, and 6 of nitrous gas; the diminution was -to 17; and pale green sulphate of iron admitted to the residuum, was -not discolored. Consequently the nitrous gas was decomposed by the -hydrogene, and as will be hereafter more clearly understood, nearly as -much nitrogene furnished by it, as would have been produced from half -the quantity of nitrous oxide. - -Suspecting that phosphorated hydrogene might inflame with nitrous -gas, I passed the electric spark through 1 measure of phosphorated -hydrogene, and 4 of nitrous gas; but no diminution was perceptible. I -likewise passed the electric spark through 1 of nitrous gas, with 2 of -phosphorated hydrogene, without inflammation. - -Perhaps if I had tried many other different proportions of the gases, I -should have at last discovered one, in which they would have inflamed; -for, as will be seen hereafter, nitrous oxide cannot be decomposed by -the compound combustible gases, except definite quantities are employed. - -From Dr. Priestley’s experiments on iron and pyrophorus, and from the -experiments I have detailed, on charcoal, phosphorus, and hydrogene, -it appears that at certain temperatures, nitrous gas is decomposable -by most of the combustible bodies: even the extinction of sulphur, when -introduced into it in a state of inflammation, depends perhaps, on the -smaller quantity of heat produced by the combustion of this body, than -that of most others. - -The analysis of nitrous gas by charcoal, as affording data for -determining immediately the quantities of oxygene and nitrogene, -ought to be considered as most accurate; and correcting it by mean -calculations derived from the decomposition of nitrous gas by -pyrophorus and hydrogene, and its conversion into nitrous oxide, a -process to be described hereafter, we may conclude, that 100 grains -of nitrous gas are composed of 55,95 oxygene, and 44,05 nitrogene; or -taking away decimals, of 56 oxygene, and 44 nitrogene. - -This estimation will agree very well with the mean proportions that -would be given from Dr. Priestley’s experiments on the decomposition -of nitrous gas by iron; but as he never ascertained the purity of his -nitrous gas,[106] and probably employed different kinds in different -experiments, it is impossible to fix on any one, from which accurate -conclusions can be drawn. - -Lavoisier’s estimation of the quantities of oxygene and nitrogene -entering into the composition of nitrous gas, has been generally -adopted. He supposes 64 parts of nitrous gas to be composed of 43½ of -oxygene, and 20½ of nitrogene.[107] - -[106] Elements English Trans. edit. i. pag. 216. - -[107] Experiments and Observations, Vol. II. pag. 40, 2d. Ed. - -The difference between this account and mine is very great indeed; -but I have already, in Division 1st, pointed out sources of error in -the experiments of this great man, on the decomposition of nitre by -charcoal; which experiments were fundamental, both to his accounts of -the constitution of nitrous acid, and nitrous gas. - - -V. _Of the absorption of Nitrous Gas by Water._ - -Amongst the properties of nitrous gas noticed by its great discoverer, -is that of absorbability by water. - -In exposing nitrous air to distilled water, Dr. Priestley found a -diminution of the volume of gas, nearly equal to one tenth of the bulk -of the water; and by boiling the water thus impregnated, he procured -again a certain portion of the nitrous gas. - -Humbolt, in his paper on eudiometry, mentions the diminution of -nitrous gas by water. This diminution, he supposes to arise from the -decomposition of a portion of the nitrous gas, by the water, and the -consequent formation of nitrate of ammoniac.[108] - -[108] He says, “On a observé, (depuis qu’on travaille sur le pureté de -l’air) que le gaz nitreux, secoué avec l’eau, en souffre une diminution -de volume. Quelques physiciens attribuent ce changement à une vraie -absorption, à une dissolution du gaz nitreux dans l’eau; d’autres -à l’air contenu dans les interstices de tous les fluides. Le cit. -Vanbreda, à Delft, a fait des recherches très-exactes sur l’influence -des eaux de pluie et de puit, sur les nombres eudiométriques; et les -belles expériences du cit. Hassenfratz, sur l’abondance d’oxygène, -contenue dans les eaux de neige et de pluie, sont supposer que l’air -des interstices de l’eau joue un rôle important dans l’absorption -du gaz nitreux. En comparant ces effets avec les phénomènes observé -dans la decomposition du sulfate de fer, nous supposâmes, le cit. -Tassaert et moi, que le simple contact du gaz nitreux avec l’eau -distillée pourroit bien causer une décomposition de ce dernier. Nous -examinâmes soigneusement une petite quantité d’eau distillée, secouée -avec beaucoup de gas nitreux trés-pur, et nous trouvâmes, au moyen de -la terre calcaire, et l’acide muriatique, qu’il s’y forme du _nitrate -d’ammoniaque_. L’eau se décompose en cette opération, par un double -affinité de l’oxygene pour le gaz nitreux, et de l’hydrogène pour -l’azote; il se forme de l’acide nitrique et de l’_ammoniaque_; et, -quoique la quantité du dernier paroisse trop petite pour en évaluer -exactment la quantité, son existence cependant se manifeste, (à ne pas -sans douter) par le dégagement des vapeurs, qui blanchissent dans la -proximité de l’acide muriatique. Voilá un fait bien frappant que la -composition d’une substance alcaline par le contact d’une acide, et de -l’eau.” - - Annales de Chimie, t. xxviii. pag. 153. - - -I confess, that even before the following experiments were made, I -was but little inclined to adopt this opinion: the small diminution -of nitrous gas by water, and the uniform limits of this diminution, -rendered it extremely improbable. - -_a._ To ascertain the quantity of nitrous gas absorbable by pure water, -and the limits of absorption, I introduced into a glass retort about 5 -ounces of water, which had been previously boiled for some hours. The -neck of the retort was inverted in mercury, and the water made to boil. -After a third of it had been distilled, so that no air could possibly -remain in the retort, the remainder was driven over, and condensed in -an inverted jar filled with mercury. To three cubic inches of this -water,[109] confined in a cylinder graduated to,05 cubic inches, 5 -cubic inches of nitrous gas, containing nearly one thirtieth nitrogene, -were introduced. - -[109] Which was certainly as free from air as it ever can be obtained. - -After agitation for near an hour, rather more than ⁴/₂₀ of a cubic inch -appeared to be absorbed; but though the process was continued for near -two hours longer, no further diminution took place. - -The remaining gas was introduced into a tube graduated to,02 cubic -inches. It measured ¹⁴/₅₀; hence ¹¹/₅₀ had been absorbed. - -Consequently, 100 cubic inches of pure water are capable of absorbing -11,8 of nitrous gas. In the water thus impregnated with nitrous gas I -could distinguish no peculiar taste;[110] it did not at all alter the -color of blue cabbage juice. - -[110] Dr. Priestley found distilled water, saturated with nitrous air, -to acquire an astringent taste and pungent smell. In some unboiled -impregnated pump water, I once thought that I perceived a subacid -taste; but it was extremely slight, and probably owing to nitrous acid -formed by the union of the oxygene of the common air in the water, with -some of the nitrous gas. - -_b._ To determine if the absorption of nitrous gas was owing, to a -decomposition of it by the water, as Humbolt has supposed, or to a -simple solution; I procured some nitrous gas from nitrous acid and -mercury, containing about one seventieth nitrogene. ,5 cubic inches -of it, mingled with ,25, of oxygene, from sulphuric acid and manganese -left a residuum of,03. 5 cubic inches more were introduced to 3 of -water, procured in the same manner as in the last experiment, in the -same cylinder. After the diminution was complete, the cylinder was -transferred in a small vessel containing mercury, into a water bath, -and nearly covered by the water. - -As the bath was heated, small globules of gas were given out from the -impregnated water, and when it began to boil, the production of gas was -still more rapid. After an hour’s ebullition, the volume of heated gas -was equal to 1,4 cubic inches nearly. - -The cylinder was now taken out of the bath, and quickly rendered cool -by being placed in a water apparatus. At the common temperature the gas -occupied, as nearly as possible, the space of,5 cubic inches: these,5 -mingled with,25 of oxygene, of the same kind as that employed before, -left a residuum nearly equal to,03. - -From this experiment, which was repeated with nearly the same results, -it is evident, - - 1. That nitrous gas is not decomposable by pure water. - - 2. That the diminution of volume of nitrous gas placed - in contact with water, is owing to a simple solution - of it in that fluid. - - 3. That at the temperature of 212°, nitrous gas is - incapable of remaining in combination with water. - -Humbolt’s opinion relating to the decomposition of nitrous gas by -water, is founded upon the disengagement of vapor from distilled water -impregnated with nitrous gas, by means of lime, which became white in -the proximity of the muriatic acid. But this is a very imperfect, and -fallacious test, of the presence of ammoniac. I have this day, April -2, 1800, heated 4 cubic inches of distilled water, impregnated with -nitrous gas, with caustic lime; the vapor certainly became a little -whiter when held over a vessel containing muriatic acid; but the vapor -of distilled water produced precisely the same appearance,[111] which -was owing, most likely, to the combination of the acid with the -aqueous vapor. Indeed, when I added a particle of nitrate of ammoniac, -which might have equalled one twentieth of a grain, to the lime and -impregnated water, the increased whiteness of the vapor was but barely -perceptible, though this quantity of nitrate of ammoniac is much more -considerable than that which could have been formed, even supposing the -nitrous gas decomposed. - -[111] As carbonic acid and ammoniac are both products of animalisation, -is it not probable that our common waters particularly those in, and -near towns and cities, contain carbonate of ammoniac? If so, this -salt will always exist in them after distillation. In the experiments -on carbonate of ammoniac, to which I have often alluded, I found, in -distilling a solution of this salt in water, that before half of the -water had passed into the recipient, the carbonate of ammoniac had -sublimed; so that the distilled solution was much stronger than before, -whilst the water remaining in the retort was tasteless. Will this -supposition at all explain Humbolt’s mistake? - - -VI. _Of the absorption of Nitrous Gas by Water of different kinds._ - -In agitating nitrous gas over spring water, the diminution rarely -amounts to more than one thirtieth, the volume of water being taken as -unity. I at first suspected that this great differcnce in the quantity -of gas absorbed by spring water, and pure water, depended on carbonic -acid contained in the last, diminishing the attraction of it for -nitrous gas: but by long boiling a quantity of spring water confined -by mercury, I obtained from it about one twentieth of its bulk of air, -which gave nearly the same diminution with nitrous gas, as atmospheric -air. - -This fact induced me to refer the difference of diminution to the -decomposition of the atmospheric air held in solution by the water, -the oxygene of which I supposed to be converted into nitric acid, by -the nitrous gas, whilst the nitrogene was liberated; and hence the -increased residuum. - -_a._ I exposed to pure water, that is, water procured by distillation -under mercury, nitrous gas, containing a known quantity of nitrogene. -After the absorption was complete, I found the same quantity of -nitrogene in the residuum, as was contained in a volume of gas equal to -the whole quantity employed. - -_b._ Spring water boiled for some hours, and suffered to cool under -mercury, absorbed a quantity of nitrous gas equal to one thirteenth of -its bulk; which is not much less than that absorbed by pure water. - -_c._ I exposed to spring water, 10 measures of nitrous gas; the -composition of which had been accurately ascertained; the diminution -was one twenty-eighth, the volume of water being taken as unity. On -placing the residuum in contact with solution of sulphate of iron, -the nitrogene remaining was nearly one twentieth more than had been -contained by the gas before its exposure to water. - -_d._ Distilled water was saturated with common air, by being agitated -for some time in the atmosphere. Nitrous gas placed in contact with -this water, underwent a diminution of ¹/₁₈; the volume of water being -unity. The gas remaining after the absorption contained about one -twenty-seventh nitrogene more than before. - -_e._ Nitrous gas exposed to water combined with about one fourth of its -volume of carbonic acid, diminished to ¹/₃₂[112] nearly. The remainder -contained little or no superabundant nitrogene. - -[112] The water still being unity. - -From these observations it appears, that the different degrees of -diminution of nitrous gas by different kinds of water, may depend upon -various causes. - -1. Less nitrous gas will be absorbed by water holding in solution -earthy salts, than by pure water; and in this case the diminution of -the attraction of water for nitrous gas will probably be in the ratio -of the quantities of salt combined with it. _a._ _b._ - -2. The apparent diminution of nitrous gas in water, holding in solution -atmospheric air, will be less than in pure water, though the absolute -diminution will be greater; for the same portion will be absorbed, -whilst another portion is combined with the oxygene of the atmospheric -air contained in the water; and from the disengagement of the nitrogene -of this air, arises an increased residuum. _c._ _d._ - -3. Probably in waters containing nitrogene, hydrogene, and other gases, -absorbable only to a slight extent, the apparent diminution will be -less, on account of the disengagement of those gases from the water, by -the stronger affinity of nitrous gas for that fluid. - -4. In water containing carbonic acid, and probably some other acid -gases, the diminution will be small in proportion to the quantity of -gas contained in the water: the affinity of this fluid for nitrous gas -being diminished by its greater affinity for the substance combined -with it. _e._ - -The different diminution of nitrous gas when agitated in different -kinds of water, has been long observed by experimenters on the -constituent parts of the atmosphere, and various solutions have been -given of the phænomenon; the most singular is that of Humbolt.[113] He -supposes that the apparent diminution of nitrous gas is less in spring -water than distilled water, on account of the decomposition of the -carbonate of lime contained in the spring water, by the nitrous acid -formed from the contact of nitrous gas with the water; the carbonic -acid disengaged from this decomposition increasing the residuum. - -[113] He says “100 parties de gaz nitreux, (à 0.14 d’azote) secouées -avec l’eau distillée, récemment cuite, diminuent en volume de 0.11, ou -0.12. Ce même gaz, en contact avec l’eau de puits, ne perd que 0.02. La -cause de cette différence de 0.9, ou 0.10, ne doit pas être attribuée -ni à l’impurité de l’air atmosphérique, contenu dans les interstices -de l’eau, ni à la décomposition de cette eau même. Elle n’est -qu’apparente; car l’acide nitrique, qui se forme par le contact du gaz -nitreux avec l’eau de puits, en décompose le carbonate de chaux. Il se -dégage de l’acide carbonique, qui, en augmentant le volume du residu, -rend l’absorption du gaz nitreux moins sensible. Pour déterminer la -quantité de cet acide carbonique, je lavai le résidu avec de l’eau de -chaux. Dans un grand nombre d’expériences, le volume diminua de 0.09, -ou 0.07. Il faut en conduire que l’eau de puits absorbe réellement 9 + -2, ou 7 + 2 parties de gas nitreux, c’est-à-dire, à peu-près la même -quantité que l’eau distillée.” - - Annales De Chimie, xxviii. pag. 154. - - -This opinion may be confuted without even reference to my -observations. It is, indeed, altogether unworthy of a philosopher, -generally acute and ingenious. He seems to have forgotten that carbonic -acid is absorbable by water. - - -VII. _Of the absorption of Nitrous Gas, by solution of pale green -Sulphate of Iron._ - -_a._ The discovery of the exact difference between the sulphates of -iron, is owing to Proust.[114] According to the ingenious researches of -this chemist, there exist two varieties of sulphate of iron, the green -and the red. The oxide in the green sulphate contains ²⁷/₁₀₀ oxygen. -This salt, when pure, is insoluble in spirit of wine; its solution in -water is of a pale green color; it is not altered by the gallic acid, -and affords a white precipitate with alkaline prussiates. - -[114] Nicholson’s Phil. Jour. No. 1, p. 453. - -The red sulphate of iron is soluble in alcohol and uncrystalizable; its -oxide contains ⁴⁸/₁₀₀ oxygene. It forms a black precipitate with the -gallic acid, and with the alkaline prussiates, a blue one. - -The common sulphates of iron generally consist of combinations of these -two varieties in different proportions. - -The green sulphate may be converted into the red by oxygenated muriatic -acid or nitric acid. The common sulphate may be converted into green -sulphate, by agitation in contact with sulphurated hydrogene. - -The green sulphate has a strong affinity for oxygene, it attracts it -from the atmosphere, from oxygenated marine acid, and nitric acid. The -alkalies precipitate from it a pale green oxide, which if exposed to -the atmosphere, rapidly becomes yellow red. - -The red sulphate of iron has no affinity for oxygene, and when -decomposed by the alkalies, gives a red precipitate, which undergoes no -alteration when exposed to the atmosphere.[115] - -[115] I have been able to make these observations on the sulphates of -iron, most of them after Proust. - -_b._ The absorption of nitrous gas by a solution of sulphate of iron, -was long ago discovered by Priestley. During this absorption, he -remarked a change of color in the solution, analogous to that produced -by the mixture of it with nitric acid. - -This chemical fact has been lately applied by Humbolt, to the discovery -of the nitrogene generally mingled with nitrous gas. - -Vauquelin and Humbolt have published a memoir, on the causes of the -absorption[116] of nitrous gas by solution of sulphate of iron. They -saturated an ounce and half of sulphate of iron in solution, with 180 -cubic inches of nitrous gas. - -[116] Annales de Chimie, vol. xxviii. pag. 182. - -Thus impregnated it strongly reddened tincture of turnsoyle; when -mingled with sulphuric acid, gave nitric acid vapor; and saturated with -potash, ammoniacal vapor. - -By analysis, it produced as much ammoniac as that contained in 4 grains -of ammoniacal muriate, and a quantity of nitric acid equal to that -existing in 17 grains of nitre. Hence they concluded, that the nitrous -gas and a portion of the water of the solution, had mutually decomposed -each other; the oxygene of the water combining with the oxygene and a -portion of the nitrogene of nitrous gas to form nitric acid; and its -hydrogene uniting with the remaining nitrogene, to generate ammoniac. - -They have taken no notice of the nature of the sulphate of iron -employed, which was most probably the common or mixed sulphate; nor of -the attraction of the oxide of iron in this substance for oxygene. - -_c._ Before I was acquainted with the observations of Proust, the -common facts relating to the oxygenation of vitriol of iron induced -me to suppose, that the attraction of this substance for oxygene was -in some way connected with the process of absorption. The comparison -of the experiments of Humbolt and Vauquelin, with the observations of -Proust, enabled me to discover the true nature of the process. - -I procured a solution of red sulphate of iron, by passing oxygenated -muriatic acid through a solution of common sulphate of iron, till it -gave only a red precipitate, when mingled with caustic potash. To -nitrous gas confined by mercury, a small quantity of this solution was -introduced. On agitation, its color altered to muddy green; but the -absorption that took place was extremely trifling: in half an hour it -did not amount to,2, the volume of the solution being unity, when it -had nearly regained the yellow color. - -I now obtained a solution of green sulphate of iron, by dissolving iron -filings in diluted sulphuric acid. The solution was agitated in contact -with sulphurated hydrogene, and afterwards boiled; when it gave a white -precipitate with prussiate of potash. - -A small quantity of this solution agitated in nitrous gas, quickly -became of an olive brown, and the gas was diminished with great -rapidity; in two minutes, a quantity equal to four times the volume of -the solution, had been absorbed. - -These facts convinced me that the solubility of nitrous gas in common -sulphate of iron, chiefly depended upon the pale green sulphate -contained by it; and that the attraction of one of the constituents of -this substance, the green oxide of iron, for oxygene, was one of the -causes of the phænomenon. - -_d._ Green sulphate of iron rapidly decomposes nitric acid. It was -consequently difficult to conceive how any affinities existing between -nitrous gas, water, and green sulphate of iron, could produce the -nitric acid found in the experiments of Vauquelin and Humbolt. - -To ascertain if the presence of a great quantity of water destroyed the -power of green sulphate of iron to decompose nitric acid, I introduced -into a cubic inch of solution of green sulphate of iron, two drops of -concentrated nitric acid. - -The solution assumed a very light olive color; prussiate of potash -mingled with a little of it, gave a dark green precipitate. Hence -the nitric acid had been evidently decomposed. As no nitrous gas was -given out, which is always the case when nitric acid is poured on -crystalised sulphate of iron, I suspected that a compleat decomposition -of the acid had taken place; but when the solution was heated, a few -minute globules of gas were liberated, and it gradually became slightly -clouded. - -Having often remarked that no precipitation is ever produced during the -conversion of green sulphate of iron into red, by oxygenated muriatic -acid, or concentrated nitric acid, I could refer the cloudiness to no -other cause than to the formation of ammoniac. - -To ascertain if this substance had been produced, a quantity of slacked -caustic lime was thrown into the solution. On the application of heat, -the ammoniacal smell was distinctly perceptible, and the vapor held -over orange nitrous acid, gave dense white fumes. - -_e._ When I considered this fact of the decomposition of nitric acid -and water by the solution of green sulphate of iron, and the change -of color effected in it by the absorption of nitrous gas, exactly -analogous to that produced by the decomposition of nitric acid; I -was induced to believe that the nitric acid found in the analysis of -Vauquelin and Humbolt, had been formed by the combination of some -of the nitrous gas thrown into the solution with the oxygene of the -atmosphere: and that the absorbability of nitrous gas, by solution of -green sulphate of iron, was owing to a decomposition produced by the -combination of its oxygene with the green oxide of iron, and of its -nitrogene with the hydrogene disengaged from water, decompounded at the -same time. - -To ascertain this, I procured a quantity of nitrous gas: it was -suffered to remain in contact with water for some hours after its -production. Transferred to the mercurial apparatus, it gave no -white vapor when placed in contact with solution of ammoniac; and -consequently held no nitric acid in solution. - -Into a graduated jar filled with mercury, a cubic inch of concentrated -solution of pure green sulphate of iron was introduced, and 7 cubic -inches of nitrous gas admitted to it. The solution immediately became -dark olive at the edges, and on agitation this color was diffused -through it. In 3 minutes, when near 5¾ cubic inches had been absorbed, -the diminution ceased. The solution was now of a bright olive brown, -and transparent at the edges. After it had rested for a quarter of an -hour, no farther absorption was observed; the color was the same, and -no precipitation could be perceived. A little of it was thrown into a -small glass tube, under the mercury, and examined in the atmosphere. -Its taste was rather more astringent than that of solution of green -sulphate; it did not at all alter the color of red cabbage juice. When -a little of it was poured on the mercury, it soon lost its color, its -taste became acid, and it quickly reddened cabbage juice, even rendered -green by an alkali. - -To the solution remaining in the mercurial jar, a small quantity of -prussiate of potash was introduced, to ascertain if any red sulphate of -iron had been formed; but instead of the production of either a blue, -or a white precipitate, the whole of the solution became opaque, and -chocolate colored. - -Surprised at this appearance, I was at first induced to suppose, -that the ammoniac formed by the nitrogene of the nitrous gas and the -hydrogene of the water, had been sufficient to precipitate from the -sulphuric acid, the red oxide of iron produced, and that the color of -the mixture was owing to this precipitation. To dissolve any uncombined -oxide that might exist in the solution, I added a very minute quantity -of diluted sulphuric acid; but little alteration of color was produced. -Hence, evidently, no red oxide had been formed. - -This unexpected result obliged me to theorise a second time, -by supposing that nitrate of ammoniac had been produced, which -by combining with the white prussiate of iron, generated a new -combination. But on mingling together green sulphate of iron, prussiate -of potash, and nitrate of ammoniac in the atmosphere, the mixture -remained perfectly white. - -To ascertain if any nitric acid existed, combined with any of the -bases, in the impregnated solution, I introduced into it an equal bulk -of diluted sulphuric acid: it became rather paler; but no green or blue -tinge was produced. - -That the prussic acid had not been decomposed, was evident from the -bright green produced, when less than a grain of dilute nitric acid was -admitted into the solution. - -_f._ From these experiments it was evident, that no red sulphate of -iron, or nitric acid, and consequently no ammoniac, had been produced -after the absorption of nitrous gas by green sulphate of iron. And when -I compared them with the observations of Priestley, who had expelled -by heat a minute quantity of nitrous gas from an impregnated solution -of common sulphate of iron, and who found common air phlogisticated by -standing in contact with it, I began to suspect that nitrous gas was -simply dissolved in the solution, without undergoing decomposition. - -_g._ To determine more accurately the nature of the process, I -introduced into a mercurial cylinder 410 grains of solution of green -sulphate of iron, occupying a space nearly equal to a cubic inch and -quarter; it was saturated with nitrous gas, by absorbing 8 cubic -inches. This saturated solution exhibited the same appearance as -the last; and after remaining near an hour untouched, had evidently -deposited no oxide of iron, nor gained any acid properties. - -Into a small mattrass filled with mercury, having a tight stopper -with a curved tube adapted to it, the greater part of this solution -was introduced; judging from the capacity of the mattrass, about 50 -grains of it might have been lost. To prevent common air from coming in -contact with the solution, the stopper was introduced into the mattrass -under the mercury; the curved tube connected with a graduated cylinder -filled with that substance; and the mattrass brought over the side of -the mercurial trough. But in spite of these precautions a large globule -of common air got into the top of the mattrass, from the curvature of -the tube. When the heat of a spirit lamp was applied to the solution, -it gave out gas with great rapidity, and gradually lost its color. -When 5 cubic inches were collected it became perfectly pale green, -whilst a yellow red precipitate was deposited on the bottom of the -mattrass. - -On pouring a little of the clear solution into prussiate of potash, it -gave only white prussiate of iron. - -But on introducing a particle of sulphuric acid into the solution, -sufficient to dissolve some of the red precipitate, and then pouring -a little of it into a solution of prussiate of potash, it gave a fine -blue prussiate of iron. - -Hence the red precipitate was evidently red yellow oxide of iron. - -I now examined the gas, suspecting that it was nitrous oxide. On -mingling a little of it with atmospheric air, it gave red vapor, and -diminished. Solution of sulphate of iron introduced to the remainder, -almost wholly absorbed it: the small residual globule of nitrogene -could not equal one thirtieth of a cubic inch. - -Consequently it was nitrous gas, nearly pure. - -Caustic potash was now introduced into the solution, till all the oxide -of iron was precipitated. The solution, when heated, gave a strong -smell of ammoniac, and dense white fumes when held over muriatic acid. -It was kept at the heat of ebullition till the evaporation had been -nearly compleated. Sulphuric acid poured upon the residuum gave no -yellow fumes, or nitric acid vapor in any way perceptible; even when -heated and made to boil, there was no indication of the production of -any vapor, except that of the sulphuric acid. - -_h._ This experiment, compared with the others, seemed almost to prove, -that nitrous gas combined with solution of pale green sulphate of -iron, at the common temperature, without decomposition; and that when -the impregnated solution was heated, the greater portion of gas was -disengaged, whilst the remainder was decompounded by the green oxide of -iron; which attracted at the same time oxygene from the water and the -nitrous gas; whilst their other constituent principles, hydrogene and -nitrogene, entered into union as ammoniac. - -Whilst, however, I was reasoning upon this singular chemical change, -as affording presumptive proofs in favor of the exertion of simple -affinities by the constituent parts of compound substances, a doubt -concerning the decomposition of the nitrous gas occurred to me. As -near as I could guess at the quantity of nitrous gas contained by -the impregnated solution, at least ¾ of it must have been expelled -undecompounded. - -More than a quarter of a cubic inch of common air had been present in -the mattrass: the oxygene of this common air must have combined with -the nitrous gas, to form nitric acid. Might not this nitric acid have -been decomposed, and furnished oxygene to the red oxide of iron, and -nitrogene to the small quantity of ammoniac found in the solution, as -in _d_? - -_i._ I now introduced to a solution of green sulphate confined by -mercury, nitrous gas, perfectly free from nitric acid. When the -solution was saturated, a portion of it was introduced into a small -mattrass filled with dry mercury, in the mercurial trough. The curved -tube was closed by a small cork at the top, and filled with nitrous -gas; it was then adapted to the mattrass, which was raised from the -trough, and the solution thus effectually preserved from the contact of -the atmosphere. - -When the heat of a spirit lamp was applied to the mattrass, it began to -give out gas with great rapidity. After some time the solution lost its -dark color, and became turbid. When the production of nitrous gas had -ceased, it was suffered to cool. A copious red precipitate had fallen -down; which, examined by the same tests as in the last experiment, -proved to be red oxide of iron. - -The solution treated with lime, as before, gave ammoniac; but with -sulphuric acid, not the slightest indications of nitric acid. - -_k._ Having thus procured full evidence of the decomposition of -nitrous gas in the heated solution, in order to gain a more accurate -acquaintance with the affinities exerted, I endeavoured to ascertain -the quantity of nitrous gas decomposed by a given solution, under known -circumstances. - -Into a cylinder of the capacity of 20 cubic inches, inverted in -mercury, 1150 grains of solution of green sulphate of iron, of specific -gravity 1,4, were introduced. Nitrous gas was admitted to it, and after -some time 21 cubic inches were absorbed. - -The impregnated solution was thrown into a mattrass, in the same manner -as in the last experiment, and the same precautions taken to preserve -it from the contact of atmospheric air. A quantity was lost during -the process of transferring, which, reasoning from the space occupied -in the mattrass by the remaining portion, as determined by experiment -afterwards, must have amounted nearly to 240 grains. - -The curved tube from the mattrass was now made to communicate with -the mercurial airholder. By the application of heat 12,5 cubic inches -of nitrous gas were collected, after the common temperature had been -restored to the mattrass; which was suffered to remain in communication -with the conducting tube. - -The solution was now pale green, that is, of its natural color, and a -considerable quantity of red oxide of iron had been deposited. - -Solid caustic potash was introduced into it, till all the green oxide -of iron had been precipitated, and till the solution rendered green, -red cabbage juice. - -A tube was now accurately connected with the mattrass, bent, and -introduced into a small quantity of diluted sulphuric acid. Nearly half -of the fluid in it was slowly distilled into the sulphuric acid, by -the heat of a spirit lamp. The impregnated acid evaporated at a heat -above 212°, and gave a small quantity of crystalised salt, which barely -amounted to two grains and quarter: it had every property of sulphate -of ammoniac. Sulphuric acid in excess was poured on the residuum, and -the whole distilled by a heat not exceeding 300°, into a small quantity -of water. This water, after the process, tasted strongly of sulphuric -acid; it had no peculiar odor. Tin thrown into it when heated, was not -perceptibly oxydated; mingled with strontitic lime water, it gave a -copious white precipitate, and after the precipitation became almost -tasteless. Hence it evidently contained no nitric acid. - -The 12,5 cubic inches of undecompounded gas that came over were -examined; and accounting for the small quantity of common air -previously contained in the airholder, must have been almost pure. - -_l._ Now supposing 927 grains of the impregnated solution (including -the weight of the nitrous gas), to have been operated upon, this must -have contained about 16,7 cubic inches of nitrous gas. But 12,5 cubic -inches escaped undecompounded: hence 4,2 were decomposed; and these -weigh 1,44 grains, and are composed of,8 oxygene, and,64 nitrogene.[117] - -Consequently, the nitrous gas must have furnished,8 of oxygene to the -green oxide of iron. - -But,64 of nitrogene require,15 of hydrogene to form,79 of -ammoniac:[118] consequently 1 of water was decompounded, and this -furnished,85 of oxygene to the green oxide of iron. - -[117] Division IV. Section 5. - -[118] Division II. Section 1. - -The green oxide of iron contains ²⁷/₁₀₀ oxygene; the red ⁴⁸/₁₀₀. But -the whole quantity of oxygene supplied from the water and nitrous -gas is 0,8 + 0,85 = 1,65; and calculating on the difference of the -composition of the red and green oxide of iron, 5,7 grains of red oxide -must have been deposited, and consequently these would saturate as -much acid as,79 grains of ammoniac, or 4,1 grains of green oxide of -iron.[119] - -And supposing the ammoniac in sulphate of ammoniac to be to the acid -as 1 is to 3,[120] 3.2 grains of sulphate of ammoniac must have been -formed, containing about 2,4 grains acid; and then 6,5 grains of green -sulphate of iron must have been decomposed. - -[119] No precipitation takes place during the conversion of solution of -green sulphate into red; and the acid appears saturated. - -[120] Division II, Section 6. - -Hence we gain the following equation: - - 6,5 green s. = 2,41 sul. acid + 4,1 gr. ox. iron. - + - 1,44 nit. gas = ,64 nitrogene + ,8 oxygene. - + - 1 water = ,85 oxygene, + ,15 hydrogene, - equal - 3,2 sul. am. = 2,41 s. acid + ,64 nit. + ,15 hyd. - + - 5,7 r. ox. iron = 4,1 gr. ox. iron + 1,6 oxyg. - -Though the estimation of the quantities in this equation must not -be considered as strictly accurate, on account of the degree of -uncertainty that remains concerning the exact numerical expression of -the quantities of the constituents of water, ammoniac, and the other -compound bodies employed; yet as founded on a simple quantity, that is, -the nitrous gas decomposed, it cannot be very distant from the truth. - -The sulphate of ammoniac given by experiment, is considerably less than -that which was really produced; much of it was probably carried off -during the evaporation of the superabundant acid. - -The conclusions that may be drawn from this experiment, afford a -striking instance of the importance of the application of the science -of quantity to the chemical changes: for the data being one chemical -fact, the decomposition of a given quantity of nitrous gas by known -agents; the composition of nitrous gas, of water, ammoniac, the oxides -of iron, and sulphate of ammoniac; we are able not only to determine -the quantities of the simple constituents that have entered into new -arrangements, but likewise the composition of two compound bodies, the -green and red sulphates of iron.[121] - -[121] According to the estimation in the equation, 6.5 of dry green -sulphate of iron contain 4.1 green oxide of iron, and 2.4 of Kirwan’s -real sulphuric acid; and 8.1 red sulphate of iron, contain 2.4 acid, -and 5.7 red oxide of iron. - -_m._ Though from the experiments in _e_ it appeared that no -decomposition of nitrous gas had been produced during or even after its -absorption by solution of sulphate of iron at the common temperature; -yet a suspicion that it might take place slowly, and that indications -of it might be given by deposition, induced me to examine minutely -two impregnated solutions, one of which had been at rest, confined by -mercury, for 19 hours, and the other for 27. In neither of them could I -discover any deposition, or alteration of color, which might denote a -change. - -Two cubic inches of oxygene were admitted to half a cubic inch of one -of these solutions. The oxygene was slowly absorbed, and the solution -gradually lost its color. - -To ascertain if during the conversion of the nitrous gas held in -solution by sulphate of iron, into nitric acid, by the oxygene of the -atmosphere at the common temperature, any water was decomposed; I -suffered an impregnated solution, weighing nearly two ounces, to remain -in contact with the atmosphere at 57°-62°, till it was become perfectly -pale. It then had a strong acid taste, effervesced with carbonate -of potash, and gave a blue precipitate with prussiate of potash.—It -was saturated with quicklime, and heated: slight indications of the -presence of ammoniac were perceived. - -As in this experiment the nitric acid had been most probably decomposed -by the green oxide of iron, as in _f_, I sent oxygenated muriatic acid -through an impregnated solution, till all the green oxide of iron was -converted into red, and all the nitrous gas into nitric acid. - -This solution saturated with potash, and heated, gave no ammoniacal -smell. - -From these experiments we may conclude, - -1st. That solution of red sulphate of iron has little or no affinity -for nitrous gas[122]; and that solution of common sulphate absorbs -nitrous gas only in proportion as it contains green sulphate. - -[122] The muddy green color produced in a solution of red sulphate of -iron agitated in nitrous gas, depended upon impurities in the mercury. -I have since found, that when the solution is completely oxygenated, -the diminution is barely perceptible. - -2dly. That solutions of green sulphate of iron dissolve nitrous gas in -quantities proportionable to their concentration, without effecting -any decomposition of it at common temperatures. And the solubility -of nitrous gas in solution of green sulphate, may be supposed to -depend on an equilibrium of affinity, produced by the following simple -attractions: - - 1. That of green oxide of iron for the oxygene - of nitrous gas and water. - - 2. That of the hydrogene of the water - for the nitrogene of the nitrous gas. - - 3. That of the principles of the sulphuric - acid, for nitrogene and hydrogene. - -3dly. That at high temperatures, that is, from 200° to 300°, the -equilibrium of affinity producing the binary combination between -nitrous gas and solution of green sulphate of iron is destroyed; the -attraction of the green oxide of iron for oxygene being increased; -whilst probably that of nitrogene for hydrogene is diminished. - -Hence the nitrous gas is either liberated,[123] in consequence of the -affinity between oxygene and hydrogene, and oxygene and nitrogene not -following the same ratio of alteration on increased temperature; or -decomposed, because at a certain temperature the green oxide exerts -such affinities upon water and nitrous gas, as to attract oxygene from -both of them to form red oxide; whilst the still existing affinity -between the hydrogene of the one, and the nitrogene of the other, -disposes them to combine to form ammoniac. - -[123] Perhaps the liberation of nitrous gas from the solution takes -place at a lower temperature than its decomposition. I have always -observed that the quantity of yellow precipitate is greater when the -solution is rapidly made to boil. Were it possible to heat it to a -certain temperature at once, probably a compleat decomposition would -take place. - -4thly. That the change of color produced by introducing nitric acid -to solution of common sulphate of iron, exactly analogous to that -occasioned in it by impregnation with nitrous gas, is owing to the -decomposition of the acid, by the combination of its oxygene with the -green oxide of iron, and of its nitrous gas with the solution. - -5thly. That nitrous gas in combination with solution of green sulphate -of iron, is capable of exerting a strong affinity upon free or loosely -combined oxygene, and of uniting with it to form nitric acid. - -_n._ The products obtained from a solution of sulphate of iron -saturated with nitrous gas, by Vauquelin and Humbolt, and their -consequent mistake with regard to the nature of the process of -absorption,[124] must have arisen from exposure of their impregnated -solution to the atmosphere. - -[124] Annales de Chimie. T. 38, pag. 187. - -Indeed, from the acidity of it, on examination, from the small portion -of ammoniac, and the large quantity of nitric acid obtained, it appears -most probable that the whole of the nitrous gas employed was converted -into nitric acid, by combining with atmospheric oxygene; for no nitric -acid could have been obtained in the mode in which they operated, -unless the green oxide of iron in the solution had been previously -converted into red. - - -VIII. _On the absorption of Nitrous Gas by solution of green Muriate of -Iron._ - -_a._ The analogy between the affinities of the constituents of the -muriate and sulphate of iron, induced me to conjecture that they -possessed similar powers of absorbing nitrous gas; and I soon found -that this was actually the case; for on agitating half a cubic inch -of solution of muriated iron, procured by dissolving iron filings -in muriatic acid, in nitrous gas, the gas was absorbed with great -rapidity, whilst the solution assumed a deep and bright brown tinge. - -_b._ Proust,[125] who as I have before mentioned, supposes the -existence of two oxides of iron only, one containing ²⁷/₁₀₀ oxygene, -the other ⁴⁸/₁₀₀, has assumed, that the muriatic acid, and most other -acids as well as the sulphuric, are capable of combining with these -oxides, and of forming with each of them a distinct salt. He has, -however, detailed no experiments on the muriates of iron. - -[125] Annales de Chimie, xxiii. pag. 85; or Nicholson’s Phil. Journal -vol. i. pag. 45. - -As these salts are still more distinct from each other in their -properties than the sulphates, and as these properties are connected -with the phænomenon of the absorption and decomposition of nitrous gas, -I shall detail the observations I have been able to make upon them. - -_c._ When iron filings have been dissolved in pure muriatic acid, and -the solution preserved from the contact of air, it is of a pale green -color, and gives a white precipitate with alkaline prussiates. The -alkalies throw down from it a light green oxide of iron. - -When evaporated, it gives crystals almost white, which are extremely -soluble in water; but insoluble in alcohol. - -The solution of green muriate of iron has a great affinity for oxygene, -and attracts it from the atmosphere, from nitric acid, and probably -from oxygenated muriatic acid. - -When red oxide of iron is dissolved in muriatic acid, or when nitric -acid is decomposed by solution of green muriate of iron; the red -muriate of iron is produced. The solution of this salt is of a deep -brown red, its odor is peculiar, and its taste, even in a very diluted -state, highly astringent. It acts upon animal and vegetable matters in -a manner somewhat analogous to the oxygenated muriatic acid, rendering -them yellowish white, or yellow.[126] - -[126] Probably by giving them oxygene; whereas the green muriate and -sulphate blacken animal substances; most likely by abstracting from -them oxygene. - -Sulphuric acid poured upon it, produces a smell resembling that of -oxygenated muriatic acid. Evaporated at a low temperature, it gives an -uncrystalisable dark, orange colored salt, which is soluble in alcohol, -and when decomposed by the alkalies, gives a red precipitate. With -prussiate of potash it gives prussian blue. - -The common muriate of iron consists of different proportions of these -two salts. It may be converted into red muriate by concentrated nitric -acid, or into green by sulphurated hydrogene. - -_d._ To ascertain if solution of red muriate of iron was capable of -absorbing nitrous gas, I introduced into a jar filled with mercury, a -cubic inch of nitrous gas, and admitted to it nearly half a cubic inch -of solution of red muriate of iron. No discoloration took place. By -much agitation, however, an absorption of nearly,2 was produced, and -the solution became of a muddy green. But this change of color, and -probably the absorption, was in consequence of the oxydation of either -the mercury, or some imperfect metals combined with it, by the oxygene -of the red muriate. For I afterwards found, that precisely the same -change of color was produced when a solution was agitated over mercury. - -_e._ I introduced to a cubic inch of concentrated solution of green -muriate of iron, 7 cubic inches of nitrous gas, free from nitric acid; -the solution instantly became colored at the edges, and on agitation -absorbed the gas with much greater rapidity than even sulphate of iron; -in a minute, only a quarter of a cubic inch remained. - -The solution appeared of a very dark brown, but evidently no -precipitation had taken place in it, and the edges, when viewed against -the light, were transparent and puce colored. - -Five cubic inches more of nitrous gas were now dissolved in the -solution. The intensity of the color increased, and after an hour no -deposition had taken place. A little of it was then examined in the -atmosphere; it had a much more astringent taste than the unimpregnated -solution, and effected no change in red cabbage juice. When prussiate -of potash was introduced into it, its color changed to olive brown. A -few drops of the solution, that had accidentally fallen on the mercury, -soon became colorless, and then effervesced with carbonate of potash, -and tasted strongly acid. - -The remainder of the impregnated solution, which must have nearly -equalled,75 cubic inches, was introduced into a mattrass, having a -stopper and curved tube, as in the experiments on the solution of -sulphate of iron; great care being taken to preserve it from the -contact of air. - -The mattrass was heated by a spirit lamp, the curved tube being in -communication with a mercurial cylinder. Near 8 cubic inches of nitrous -gas were collected, when the solution became of a muddy yellow. It was -suffered to cool, and examined. A small quantity of yellow precipitate -covered the bottom of the mattrass; the fluid was pellucid, and -light green. A little of it thrown on prussiate of potash, gave a -white precipitate, colored by streaks of light blue. When the yellow -precipitate was partly dissolved by sulphuric acid, a drop of the -solution, mingled with prussiate of potash, gave a deep blue green. - -Hence, evidently, the precipitate was red oxide of iron. - -Caustic potash in excess was introduced into the remainder of the -solution, and it was heated. It gave an evident smell of ammoniac, and -dense white fumes, when held over strong phlogisticated nitrous acid. - -When half of it was evaporated, sulphuric acid in excess was poured on -the remainder; muriatic acid was liberated, not perceptibly combined -with any nitric acid. - -_f._ In an experiment that I made to ascertain the quantity of nitrous -gas capable of combining with solution of green muriate of iron; I -found that,75 cubic inches of saturated solution absorbed about 18 -of nitrous gas, which is nearly double the quantity combinable with -an equal portion of the strongest solution of sulphate of iron. A -part of this impregnated solution, heated slowly, gave out more -gas in proportion to the quantity it contained, than the last, and -consequently produced less precipitate; so that I am inclined to -suppose it probable, that at a certain temperature, all the dissolved -nitrous gas may be dispelled from a solution. - -From these experiments we may conclude, - -1st. That the solution of green muriate of iron absorbs nitrous gas in -consequence of nearly the same affinities as solution of green sulphate -of iron; its capability of absorbing larger quantities depending -most probably on its greater concentration (that is, on the greater -solubility of the muriate of iron), and perhaps, in some measure, on a -new combining affinity, that of muriatic acid for oxygene. - -2dly. That at certain temperatures nitrous gas is either liberated from -solution of green muriate, or decomposed, by the combination of its -oxygene with green oxide of iron, and of its nitrogene with hydrogene, -produced from water decompounded by the oxide at the same time. - - -IX. _Absorption of Nitrous Gas by Solution of Nitrate of Iron._ - -_a._ As well as two sulphates and two muriates of iron, there exist two -nitrates.[127] When concentrated nitric acid is made to act upon iron, -nitrous gas is disengaged with great rapidity, and with great increase -of temperature: the solution assumes a yellowish tinge, and as the -process goes on, a yellow red oxide is precipitated. - -[127] The existence of green nitrate was not suspected by Proust. - -Nitrate of iron made in this way, gives a bright blue mingled with -prussiate of potash, and decomposed by the alkalies, a red precipitate. -Its solution has little or no affinity for nitrous gas. - -_b._ When very dilute nitric acid, that is, such as of specific gravity -1,16, is made to oxydate iron, without the assistance of heat, the -solution gives out no gas for some time, and becomes dark olive brown: -when neutralised it gives, decomposed by the alkalies, a light green -precipitate; and mingled with prussiate of potash, pale green prussiate -of iron. - -It owes its color to the nitrous gas it holds in solution. By exposure -to the atmosphere it becomes pale, the nitrous gas combined with it -being converted into nitric acid. - -It is then capable of absorbing nitrous gas, and consists of pale -nitrate of iron, mingled with red nitrate. - -I have not yet obtained a nitrate of iron giving only a white -precipitate with prussiate of potash, that is, such as contains _only_ -oxide of iron at its minimum of oxydation; for when pure green oxide -of iron is dissolved by very dilute nitric acid, a small quantity of -the acid is generally decomposed, which is likewise the case in the -decomposition of nitre by green sulphate of iron. The solutions of -nitrate of iron, however, procured in both of these modes, absorb -nitrous gas with rapidity, and by sulphurated hydrogene might probably -be converted into pale nitrate. - -As it is impossible to obtain concentrated solutions of pale nitrate of -iron, chiefly containing green oxide, its powers of absorbing nitrous -gas cannot be compared with the muriatic and sulphuric solutions, -unless they are made of nearly the same specific gravity. - -Nitrous gas is disengaged by heat from the impregnated solution of -nitrate of iron, at the same time that much red oxide of iron is -precipitated. Whether any nitrous gas is decomposed, I have not yet -ascertained; for when unimpregnated pale nitrate of iron is heated, -a part of the acid, and of the water of the solution, is decomposed -by the green oxide of iron;[128] and in consequence ammoniac, and red -nitrate of iron formed, whilst red oxide is precipitated. - -[128] In this process nitrous oxide is sometimes given out, as will be -seen hereafter. - - -X. _Absorption of Nitrous Gas by other Metallic Solutions._ - -_a._ White prussiate of iron in contact with water absorbs nitrous gas -to a great extent, and becomes dark chocolate.[129] - -_b._ Concentrated solution of sulphate of tin, _probably_ at its -minimum of oxydation, absorbs one eighth of its bulk of nitrous gas, -and becomes brown, without deposition. - -_c._ Solution of sulphate of zinc absorbs about one tenth of its volume -of nitrous gas, and becomes green. - -_d._ Solution of muriate of zinc[130] absorbs nearly the same quantity, -and becomes orange brown. - -[129] Hence we learn why no nitrous gas is disengaged when impregnated -solution of sulphate of iron is decomposed by prussiate of potash, as -in Div. IV. Sec. vii. - -[130] In both of these solutions the metal is at its minimum of -oxydation. The absorption of a small quantity of nitrous gas by white -vitriol was observed by Priestley. - -_e._ These are all the metallic substances on which I have -experimented. It is more than probable that there exist others -possessing similar powers of absorbing nitrous gas. - -Whenever the metals capable of decomposing water exist in solutions at -their minimum of oxydation, the affinities exerted by them on nitrous -gas and water, will be such as to produce combination. The powers of -metallic solutions to combine with nitrous gas at common temperatures, -as well as to decompose it at higher temperatures, will probably be -in the ratio of the affinity of the metallic oxides they contain, for -oxygene. - - -XI. _The action of Sulphurated Hydrogene on solution of Green Sulphate -of Iron, impregnated with Nitrous Gas._ - -_a._ In an experiment on the absorption of nitrous gas by solution of -green sulphate of iron, I introduced an unboiled solution of common -sulphate, deprived of red oxide of iron by sulphurated hydrogene, into -a jar filled with nitrous gas; the absorption took place as usual, -and nearly six of gas entered into combination, the volume of the -solution being unity. On applying heat to a part of this impregnated -solution, the whole of the nitrous gas it contained (as nearly as I -could guess), was expelled undecompounded, and no yellow precipitate -produced. Prussiate of potash poured into it gave only white prussiate -of iron; and when it was heated with lime, no ammoniacal smell was -perceptible. - -I could refer this phænomenon to no other cause than to the existence -of a small quantity of sulphurated hydrogene in the solution. That this -was the real cause I found from the following experiment. - -_b._ One part of a solution of green sulphate of iron, formed by the -agitation of common sulphate of iron in contact with sulphurated -hydrogene, was boiled for some minutes to expel the small quantity of -gas retained by it undecompounded. It had then no peculiar smell, and -gave a white prussiate of iron with prussiate of potash; the other -part had a faint odor of sulphurated hydrogene, and gave a dirty white -precipitate with prussiate of potash. Nearly equal quantities of each -were saturated with nitrous gas, and heated. The unboiled impregnated -solution gave out all its nitrous gas undecompounded; whilst in the -boiled solution it was partly decomposed, yellow precipitate and -ammoniac being formed. - -_c._ This singular phænomenon of the power of a minute quantity of -sulphurated hydrogene, in preventing the decomposition of nitrous gas -and water, by green oxide of iron, will most probably take place in -other impregnated solutions. It seems to depend on the strong affinity -of the hydrogene of sulphurated hydrogene for oxygene. - - -XII. _Additional Observations._ - -_a._ For separating nitrous gas from gases absorbable to no great -extent by water; a well boiled solution of green muriate of iron -should be employed. Nitrous gas agitated in this is rapidly absorbed, -and it has no affinity for, or action on, nitrogene, hydrogene, or -hydrocarbonate. - -_b._ Nitrous gas carefully obtained from mercury and nitric acid, when -received under mercury, or boiled water, and absorbed by solution of -green muriate, or sulphate of iron, rarely leaves a residuum of ¹/₂₀₀ -of its volume: preserved over common water, and absorbed, the remainder -is generally from ¹/₄₀ to ¹/₉₀, from the nitrogene disengaged by the -decomposition of the common air contained in the water. - -_c._ The nitrous gas carefully obtained from the decomposition of -nitric acid of 1,26, by copper, I have hardly ever found to contain -more than from ¹/₃₀ to ¹/₅₀ nitrogene, when received through common -water: when boiled water is employed, the residuum is nearly the same -as that of nitrous gas obtained from mercury. - -_d._ Consequently the gas from those two solutions may be used in -common. It is more than probable, that the small quantities of -nitrogene generally mingled with nitrous gas from copper and mercury, -arise either from the common air of the vessels in which it was -produced, or that of the water over which it was received. There is no -reason for supposing that it is generated by a complete decomposition -of a portion of the acid.[131] - -[131] Humbolt, who is the first philosopher that has applied the -solution of sulphate of iron to ascertain the purity of nitrous gas, -asserts that he uniformly found nitrous gas obtained from solution -of copper in nitrous acid, to contain from six tenths to one tenth -nitrogene. - - Annales de Chimie, vol. xxviii. pag. 147. - - -_e._ Whenever nitrous oxide is mingled with nitrous gas and nitrogene, -it must be separated by well boiled water; and after the corrections -are made for the quantity of air disengaged from the water, the nitrous -gas absorbed by the muriatic solution. - - -DIVISION V. - - _EXPERIMENTS and OBSERVATIONS on the production of - NITROUS OXIDE from NITROUS GAS and NITRIC ACID, in - different modes._ - - -I. _Preliminaries._ - -_a._ The opinions of Priestley[132] and Kirwan,[133] relating to the -causes of the conversion of nitrous gas into nitrous oxide, were -founded on the theory of phlogiston. The first of these philosophers -obtained nitrous oxide by placing nitrous gas in contact with moistened -iron filings, or the alkaline sulphures. The last by exposing it to -sulphurated hydrogene. - -[132] Vol. ii. pag. 55. - -[133] Phil. Trans. vol. lxxvi. pag. 133. - -The Dutch chemists,[134] the latest experimentalists on nitrous oxide, -have supposed that the production of this substance depends upon the -simple abstraction of a portion of the oxygene of nitrous gas. They -obtained nitrous oxide by exposing nitrous gas to muriate of tin, to -copper in solution of ammoniac, and likewise by passing it over heated -sulphur. - -[134] Journal de Physique, tom. xliii. 323. - -The diminution of volume sustained by nitrous gas during its conversion -into nitrous oxide, has never been accurately ascertained; it has -generally been supposed to be from two thirds to eight tenths. - -_b._ Nitrous gas may be converted into nitrous oxide in two modes. - -First, by the simple abstraction of a portion of its oxygene, by bodies -possessing a strong affinity for that principle, such as alkaline -sulphites, muriate of tin, and dry sulphures. - -Second, by the combination of a body with a portion both of its oxygene -and nitrogene, such as hydrogene, when either in a nascent form, or a -peculiar state of combination. - -_c._ Each of these modes will be distinctly treated of; and to prevent -unnecessary repetitions, I shall give an account of the general manner -in which the following experiments on the conversion of nitrous gas -into nitrous oxide, have been conduced. - -Nitrous gas, the purity of which has been accurately ascertained by -solution of muriate of iron, is introduced into a graduated jar filled -with dry mercury. If a fluid substance is designed for the conversion -of the gas into nitrous oxide, it is heated, to expel any loosely -combined air which might be liberated during the process; and then -carefully introduced into the jar, by means of a small phial. After -the process is finished, and the diminution accurately noted, the -nitrous oxide formed is absorbed by pure water. If any nitrous gas -remains, it is condensed by solution of muriate of iron; other residual -gases are examined by the common tests. The quantity of nitrous oxide -dissolved by the fluid is determined by a comparative experiment; and -the corrections for temperature and pressure being guessed at, the -conclusions drawn. - -If a solid substance is used, rather more nitrous gas than that -designed for the conversion, is introduced into the jar. The substance -is brought in contact with the gas, by being carried under the mercury; -and as a little common air generally adheres to it, a small portion -of the nitrous gas is transferred into a graduated tube, after the -insertion, and its purity ascertained. In other respects the process is -conducted as mentioned above. - - -II. _Of the conversion of Nitrous gas into Nitrous Oxide, by Alkaline -Sulphites._ - -The alkaline sulphites, particularly the sulphite of potash, convert -nitrous gas into nitrous oxide, with much greater rapidity than any -other bodies. - -At temperature 46°, 16 cubic inches of nitrous gas were converted, in -less than an hour, into 7,8 of nitrous oxide, by about 100 grains of -pulverised sulphite of potash, containing its water of crystalisation. -No sensible increase of temperature was produced during the process, -no water was decomposed, and the quantity of nitrogene remaining after -the experiment, was exactly equal to that previously contained in the -nitrous gas. - -The nitrous oxide produced from nitrous gas by sulphite of potash, has -all the properties of that generated from the decomposition of nitrate -of ammoniac. It gives, as will be seen hereafter, the same products by -analysis. Phosphorus, the taper, sulphur, and charcoal, burn in it with -vivid light. It is absorbable by water, and capable of expulsion from -it unaltered, by heat. - -Nitrous gas is converted into nitrous oxide by the alkaline sulphites -with the same readiness, whether exposed to the light, or deprived of -its influence. - -The solid sulphites act upon nitrous gas much more readily than -their concentrated solutions; they should however always be suffered -to retain their water of crystalisation, or otherwise they attract -moisture from the gas, and render it drier, and in consequence more -condensed than it would otherwise be. In case perfectly dry sulphites -are employed, the gas should be always saturated with moisture after -the experiment, by introducing into the cylinder a drop of water. - -The sulphites, after exposure to nitrous gas, are either found wholly, -or partially, converted into sulphates. Consequently the conversion of -nitrous gas into nitrous oxide by these bodies, simply depends on the -abstraction of a portion of its oxygene; the nitrogene and remaining -oxygene assuming a more condensed state of existence. - -If we reason from the different specific gravities of nitrous oxide and -nitrous gas, as compared with the diminution of volume of nitrous gas, -during its conversion into nitrous oxide, 100 parts of nitrous gas, -supposing the former estimation of the composition of nitrous oxide -given in Division III, accurate, would consist of 54 oxygene, and 46 -nitrogene; which is not far from the true estimation. Or assuming the -composition of nitrous gas, as given in Division IV, it would appear -from the diminution, that 100 parts of nitrous oxide consisted of 38 -oxygene, and 62 nitrogene. - - -III. _Conversion of Nitrous Gas into Nitrous Oxide, by Muriate of Tin, -and dry Sulphures._ - -_a._ Nitrous gas exposed to dry muriate of tin, is slowly converted -into nitrous oxide: during this process the apparent diminution is -to about one half; but if the products are nicely examined, and the -necessary corrections made, the real diminution of nitrous gas by -muriate of tin, will be the same as by the sulphites; that is, 100 -parts of it will be converted into 48 of nitrous oxide. - -During this conversion, no water is decomposed, and no nitrogene -evolved. Solution of muriate of tin converts nitrous gas into nitrous -oxide; but with much less rapidity than the solid salt. - -_b._ Nitrous gas exposed to dry and perfectly well made sulphures, -particularly such as are produced from crystalised alumn[135] and -charcoal not sufficiently inflammable to burn in the atmosphere, is -converted into nitrous oxide by the simple abstraction of a portion of -its oxygene, and consequently undergoes a diminution of ⁵²/₁₀₀. - -It is probable, that all the bodies having strong affinity for oxygene -will, at certain temperatures, convert nitrous gas into nitrous oxide. -Priestley, and the Dutch chemists, effected the change by heated -sulphur. Perhaps nitrous gas sent through a tube heated, but not -ignited, with phosphorus, would be converted into nitrous oxide. - -[135] That is, alumn containing sulphate of potash. - - -IV. _Decomposition of Nitrous Gas, by Sulphurated Hydrogene._ - -_a._ When nitrous gas and sulphurated hydrogene are mingled together, -a decomposition of them slowly takes place. The gases are diminished, -sulphur deposited, nitrous oxide formed, and signs of the production of -ammoniac[136] and water perceived. - -[136] The production of ammoniac in this process was observed by Kirwan -and Austin. - -In this process no sulphuric, or sulphureous acid is produced; -consequently none of the sulphur is oxydated, and of course the changes -depend upon the combination of the hydrogene of the sulphurated -hydrogene, with different portions of the oxygene and nitrogene of the -nitrous gas, to form water and ammoniac, the remaining oxygene and -nitrogene assuming the form of nitrous oxide. - -This singular exertion of attractions by a simple body, appears -highly improbable a priori, nor did I admit it, till the formation of -ammoniac, and the non-oxygenation of the sulphur, were made evident by -many experiments. - -In those experiments, the diminution of the nitrous gas was not -uniformly the same. It varied from ¹¹/₂₀ to ¹⁴/₂₀. In the most accurate -of them, 5 cubic inches of nitrous gas were converted into 2.2 of -nitrous oxide. Consequently the quantity of ammoniac formed was,047 -grains. - -In experiments on the conversion of nitrous gas into nitrous oxide, by -sulphurated hydrogene, the gases should be rendered as dry as possible. -The presence of water considerably retards the decomposition. - -_b._ The sulphures[137] dissolved in water convert nitrous gas into -nitrous oxide. This decomposition is not, however, produced by the -simple abstraction of oxygene from the nitrous gas to form sulphuric -acid. It depends as well on the decomposition of the sulphurated -hydrogene dissolved in the solution, or liberated from it. In this -process sulphur is deposited on the surface of the fluid, sulphuric -acid is formed, and the diminution, making the necessary corrections, -is nearly the same as when free sulphurated hydrogene is employed. - -[137] Solution of sulphure of strontian, or barytes, should be used. -During the conversion of nitrous gas into nitrous oxide by those -bodies, a thin film is deposited on the surface of the solution. -This film examined, is found to consist of sulphur and sulphate. -Possibly the nitrous gas is wholly decomposed by the hydrogene of the -sulphurated hydrogene in the solution, whilst the sulphate is produced -from water decompounded by the sulphur to form more gas for the -saturation of the hydro-sulphure. - -It is extremely probable that sulphurated hydrogene, in combination -with the alkalies, as well as with water, is capable of being slowly -decomposed by nitrous gas. - - -V. _Decomposition of Nitrous Gas by Nascent Hydrogene._ - -_a._ When nitrous gas, is exposed to wetted iron filings, a diminution -of its volume slowly takes place; and after a certain time, it is found -converted into nitrous oxide. - -In this process ammoniac[138] is formed, and the iron partially -oxydated. - -[138] As was first observed by Priestley and Austin, and as I have -proved by many experiments. - -The water in contact with the iron is decomposed by the combination of -its oxygene with that substance, and of its hydrogene with a portion -of the oxygene and nitrogene of the nitrous gas, to form water and -ammoniac. - -That the iron is not oxydated at the expence of the oxygene of the -nitrous gas, appears very probable from the analogy between this -process, and the mutual decomposition of nitrous gas and sulphurated -hydrogene. Besides, dry iron filings effect no change whatever in -nitrous gas, at common temperatures. - -I have generally found about 12 of nitrous gas converted into 5 of -nitrous oxide in this process; which is not very different from the -diminution by sulphurated hydrogene. It takes place equally well in -light and darkness; but more rapidly in warm weather than in cold. - -_b._ Nitrous gas exposed to a large surface of zinc, in contact with -water, is slowly converted into nitrous oxide; at the same time that -ammoniac is generated, and white oxide of zinc formed. This process -appears to depend, like the last, upon the decomposition of water by -the affinities of part of the oxygene and nitrogene of nitrous gas, -for its hydrogene, to form ammoniac and water; and by that of zinc -for its oxygene. Zinc placed in contact with water, and confined by -mercury,[139] decomposes it at the common temperature. Zinc, when -perfectly dry, does not in the slightest degree act upon nitrous gas. - -[139] As I have found by experiment. - -I have not been able to determine exactly the diminution of volume of -nitrous gas, during its conversion into nitrous oxide by zinc. In one -experiment 20 measures of nitrous gas, containing about,03 nitrogene, -were diminished to 9, after an exposure of eight days to wetted zinc; -but from an accident, I was not able to ascertain the exact quantity of -nitrous oxide formed. - -_c._ It is probable that most of the imperfect metals will be found -capable of oxydation, by the decomposition of water, when its -hydrogene is attracted by the oxygene and nitrogene of nitrous gas. -I have this day (April 14, 1800), examined two portions of nitrous -gas, one of which had been exposed to copper filings, and the other to -powder of tin, for twenty-three days. - -The gas that had been exposed to copper was diminished nearly two -fifths. The taper burnt in it with an enlarged flame, blue at the -edges. Hence it evidently contained nitrous oxide. - -The nitrous gas in contact with tin had undergone a diminution of one -fourth only, and did not support flame. - - -VI. _Miscellaneous Observations on the conversion of Nitrous Gas into -Nitrous Oxide._ - -_a._ Dr. Priestley found nitrous gas exposed to a mixture of iron -filings and sulphur, with water, converted after a certain time, into -nitrous oxide. Sulphurated hydrogene is always produced during the -combination of iron and sulphur, when they are in contact with water; -and by the hydrogene of this in the nascent state, the nitrous gas is -most probably decomposed. - -_b._ Green oxide of iron moistened with water, exposed to nitrous gas, -slowly gains an orange tinge, whilst the gas is diminished. Most likely -it is converted into nitrous oxide; but this I have not ascertained. - -_c._ I exposed nitrous gas, to the following bodies over mercury -for many days, without any diminution, or apparent change in its -properties. Alcohol, saccharine matter, hydrocarbonate, sulphureous -acid, and phosphorus. - -_d._ Crystalised sulphate, and muriate of iron, absorb a small quantity -of nitrous gas, and become dark colored on the outside; but after this -absorption, (which probably depends on their water of crystalisation,) -has taken place, no change is effected in the gas remaining. - -_e._ The power of iron to decompose water being much increased by -increase of temperature, nitrous gas is converted into nitrous oxide -much more rapidly when placed in contact with a surface of heated -iron, than when exposed to it at common temperatures. During the -decomposition of nitrous gas in this way, ammoniac[140] is formed. - -_f._ The curious experiments of Rouppe,[141] on the absorption of gases -by charcoal, compared with the phænomena noticed in this Division, -render it probable that hydrogene in a state of loose combination with -charcoal, will be found to convert nitrous gas into nitrous oxide. - -[140] As was observed by Milner. Nitrous gas passed over heated zinc, -or tin, I doubt not will be found converted into nitrous oxide. - -[141] Annales de Chimie, xxxii. p. 3. - - -VII. _Recapitulation of conclusions concerning the conversion of -Nitrous Gas into Nitrous Oxide._ - -_a._ Certain bodies having a strong affinity for oxygene, as the -sulphites, dry sulphures, muriate of tin, &c. convert nitrous gas into -nitrous oxide, by simply attracting a portion of its oxygene; whilst -the remaining oxygene enters into combination with the nitrogene, and -they assume a more condensed state of existence. - -_b._ Nitrous gas is converted into nitrous oxide by hydrogene, in a -peculiar state of existence, as in sulphurated hydrogene; and that by -a series of very complex affinities. Both oxygene and nitrogene are -attracted from the nitrous gas by the hydrogene, in such proportions -as to form water and ammoniac, whilst the remaining oxygene and -nitrogene[142] assume the form of nitrous oxide. - -[142] The decomposition and recomposition of water, in this process, -are analogous to some of the phænomena observed by the ingenious Mrs. -Fulhame. - -_c._ Nitrous gas placed in contact with bodies, such as iron and -zinc decomposing water, is converted into nitrous oxide, at the same -time that ammoniac is formed. It is difficult to ascertain the exact -rationale of this process. For either the nascent hydrogene produced by -the decomposition of the water by the metallic substance may combine -with portions of both the oxygene and nitrogene of the nitrous gas; and -thus by forming water and ammoniac, convert it into nitrous oxide. Or -the metallic substance may attract at the same time oxygene from the -water and nitrous gas, whilst the nascent hydrogene of the water seizes -upon a portion of the nitrogene of the nitrous gas to form ammoniac. - -The degree of diminution, and the analogy between this process and the -decomposition of nitrous gas by sulphurated hydrogene, render the first -opinion most probable. - - -VIII. _The production of Nitrous Oxide during the oxydation of Tin, -Zinc, and Iron, in Nitric Acid._ - -_a._ Dr. Priestley discovered, that during the solution of tin, zinc, -and iron, in nitric acid, certain portions of nitrous oxide were -produced, mingled with quantities of nitrous gas, and nitrogene, -varying in proportion as the acid employed was more or less -concentrated. - -It has long been known that ammoniac is formed during the solution of -tin, zinc, and iron, in diluted nitric acid. Consequently, in these -processes water is decomposed. - -I had designed to investigate minutely these phænomena, so as to -ascertain the quantities of water and acid decompounded, and of the new -products generated. But after going through some experiments on the -oxydation of tin without gaining conclusive results, the labor, and -sacrifice of time they demanded, obliged me to desist from pursuing the -subject, till I had completed more important investigations. - -I shall detail the few observations which have occurred to me, relating -to the production of nitrous oxide from metallic solutions. - -_b._ When tin is dissolved in concentrated nitric acid, such as of -1.4, nitrous oxide is produced, mingled with generally more than twice -its bulk of nitrous gas. In this process but little free nitrogene is -evolved, and the tin is chiefly precipitated in the form of a white -powder. If the solution, after the generation of these products, is -saturated with lime, and heated, the ammoniacal smell is distinct. - -When nitric acid of specific gravity 1.24, is made to act upon tin; -in the beginning of the process, nearly equal parts of nitrous gas -and nitrous oxide are produced; as it advances, the proportion of -nitrous oxide to the nitrous gas increases: the largest quantity of -nitrous oxide that I have found in the gas procured from tin is ¾, the -remainder being nitrous gas and nitrogene. - -When tin is oxydated in an acid of less specific gravity than 1.09, the -quantities of gas disengaged are very small, and consist of nitrogene, -mingled with minute portions of nitrous oxide, and nitrous gas. - -Whenever I have saturated solutions of tin in nitric acid of different -specific gravities, with lime, and afterwards heated them, the -ammoniacal smell has been uniformly perceptible, and generally most -distinct when diluted acids have been employed. - -_c._ When zinc is dissolved in nitric acid, whatever is its specific -gravity, certain quantities of nitrous oxide are produced. - -Nitric acids of greater specific gravity than 1.2, act upon zinc with -great rapidity, and great increase of temperature. The gases disengaged -from these solutions consist of nitrous gas, nitrous oxide, and -nitrogene; the nitrous oxide rarely equals one third of the whole. - -When nitric acid of 1,104 is made to dissolve zinc, the gas obtained in -the middle of the process consists chiefly of nitrous oxide. From such -a solution I obtained gas which gave a residuum of one sixth only when -absorbed by water. The taper burnt in it with a brilliant flame, and -sulphur with a vivid rose-colored light. - -100 grains of granulated zinc, during their solution in 300 grains -of nitric acid, of 1,43, diluted with 14 times its weight of water, -produced 26 cubic inches of gas. Of this gas ⁷/₃₆ were nitrous, ¹⁷/₃₆36 -nitrous oxide, and the remainder nitrogene. The solution saturated with -lime and heated, gave a distinct smell of ammoniac. - -_d._ During the solution of iron in concentrated nitric acid, the gas -given out is chiefly nitrous; it is however generally mingled with -minute quantities of nitrous oxide. When very dilute nitric acids -are made to act upon iron, by the assistance of heat, nitrous oxide -is produced in considerable quantities, mingled with nitrous gas -and nitrogene; the proportions of which are smaller as the process -advances.[143] The fluid remaining after the oxydation and solution of -iron in nitric acid, always contains ammoniac. - -[143] From one of Dr. Priestley’s experiments, it appears that -hydrogene gas is sometimes disengaged during the solution of iron in -very dilute nitric acid by heat. This phænomenon has never occurred to -me. - -_e._ As during the solution of tin, zinc, and iron, in nitric acid, the -quantity of acid is diminished in proportion as the process advances, -it is reasonable to suppose that the relative quantities of the gases -evolved are perpetually varying. In the beginning of a dissolution, -the nitrous gas generally predominates, in the middle nitrous oxide, -and at the end nitrogene. - -_f._ During the generation of nitrous gas, nitrous oxide, and ammoniac, -from the decomposition of solution of nitric acid in water, by tin, -zinc, and iron, very complex attractions must exist between the -constituents of the substances employed. The acid and the water are -decomposed at the same time, and in proportions different as the -solution is more concentrated, by the combination of their oxygene with -the metallic body. - -The nitrous gas is produced by the combination of the metal with -³²/₁₀₀ of the oxygene of the acid. The nitrous oxide is most probably -generated by the decomposition of a portion of the nitrous gas -disengaged, by the nascent hydrogene of the water decompounded; some -of it may be possibly formed from a more complete decomposition of the -acid. - -The production of ammoniac may arise, probably from two causes; from -the decomposition of the nitrous gas by the combination of the nascent -hydrogene of the water, with portions of its oxygene and nitrogene at -the same time; and from the union of hydrogene with nascent nitrogene -liberated in consequence of a complete decomposition of part of the -acid. - - -IX. _Additional Observations on the production of Nitrous Oxide._ - -_a._ When nitric acid is combined with muriatic acid, or sulphuric -acid,[144] the quantities of nitrous oxide produced from its -decomposition by tin, zinc, and iron, are rather increased than -diminished. The nitrous oxide obtained from these solutions is, -however, never sufficiently pure for physiological experiments. It is -always mingled with either nitrous gas, nitrogene, or hydrogene, and -sometimes with all of them. - -[144] As was discovered by Priestley, and the Dutch Chemists. - -_b._ From the solutions of bismuth, nickel, lead, and copper, in -diluted nitric acid, I have never obtained any perceptible quantity -of nitrous oxide: the gas produced is nitrous, mingled with different -portions of nitrogene. Antimony and mercury, during their solution in -aqua regia, give out only nitrous gas. - -Probably none of the metallic bodies, except those that decompose -water at temperatures below ignition, will generate nitrous oxide from -nitric acid. On cobalt and manganese I have never had an opportunity of -experimenting: manganese will probably produce nitrous oxide. - -_c._ During the solution of vegetable matters[145] in nitric acid, by -heat, very minute portions of nitrous oxide are sometimes produced, -always however mingled with large quantities of nitrous gas, and -carbonic acid. - -[145] Such as the leaves, bark, and wood, of trees. - -When nitric acid is decompounded by ether, fixed oils, volatile oils, -or alcohol, towards the end of the process small quantities of nitrous -oxide are produced, and sometimes sufficiently pure to support the -flame of the taper.[146] - -_d._ When green oxide of iron is dissolved in nitric acid, nitrous -oxide is produced, mingled with nitrogene and nitrous gas. - -_e._ During the conversion of green sulphate, or green muriate of iron -into red, by the decomposition of dilute nitric acid, nitrous oxide is -formed, mingled with different proportions of nitrous gas and nitrogene. - -_f._ When solution of green nitrate of iron is heated, a part of the -acid is decomposed, red oxide is precipitated, red nitrate formed, and -impure nitrous oxide evolved. - -_g._ When iron is introduced into a solution of nitrate of copper, the -copper is precipitated in its metallic state, whilst nitrous oxide, -mingled with small portions of nitrogene, is produced.[147] - -[146] As I have observed after Priestley. - -[147] As was discovered by Priestly. - -Both zinc and tin precipitate copper in its metallic form from -solution in the nitric acid. During these precipitations, certain -quantities of nitrous oxide are generated, mingled however with larger -quantities of nitrogene than that produced from decomposition by iron. -In all these processes ammoniac is formed, and water consequently -decomposed. - -The decomposition of water and nitric acid, during the precipitation -of copper from solution of nitrate of copper, by tin, zinc, and iron, -depends upon the strong affinity of those metals for oxygene, and their -powers of combining with a larger quantity of it than copper. - - -X. _Decomposition of Aqua Regia by Platina, and evolution of a Gas -analogous to Oxygenated Muriatic Acid, and Nitrogene._ - -_a._ De la Metherie, in his essay on different airs, has asserted that -the gas produced by the solution of platina in nitro-muriatic acid, is -identical with the dephlogisticated nitrous gas of Priestly. He calls -it nitrous gas with excess of pure air, and affirms that it diminishes, -both with nitrous gas and common air. - -_b._ I introduced into a vessel containing 30 grains of platina, -2050 grains of aqua regia, composed of equal parts, by weight, of -concentrated nitric acid of 1,43, and muriatic acid of 1,16. At the -common temperature, that is, 49°, no action between the acid and -platina appeared to take place. On the application of the heat of a -spirit lamp, the solution gradually became yellow red, and gas was -given out with rapidity. Some of this gas received in a jar filled -with warm water, appeared of a bright yellow color. On agitation, -the greater part of it was absorbed by the water, and the remainder -extinguished flame. When it was received over mercury, it acted upon it -with great rapidity, and formed on the surface a white crust. - -As the process of solution advanced, the color of the acid changed -to dark red, at the same time that the production of gas was much -increased; more than 40 cubic inches were soon collected in the water -apparatus. - -Different portions of the gas were examined, it exhibited the following -properties: - - 1. Its color was orange red,[148] and its smell exactly - resembled that of oxygenated muriatic acid. - - 2. When agitated in boiled water, it was rapidly absorbed, - leaving a residuum of rather more than one twelfth. - - 3. The taper burnt in it with increased brilliancy, - the flame being long, and deep red at the edges. - - 4. Iron introduced into it ignited, burnt with a dull - red light. - - 5. Green vegetables exposed to it were instantly - rendered white. - - 6. It underwent no diminution, mingled with - atmospheric air. - - 7. When mingled with nitrous gas, it gave dense red - vapor, and rapid diminution. - -[148] This deep color depended, in some measure, upon the -nitro-muriatic vapor suspended in it. I have since observed that it is -more intense in proportion as the heat employed for the production of -the gas has been stronger. The natural color of the peculiar gas is -deep yellow. - -_c._ From the exhibition of these properties, it was evident that the -gas produced during the solution of platina in aqua regia, chiefly -consisted of oxygenated muriatic acid, or of a gas highly analogous to -it. It was, however, difficult to conceive how a body, by combining -with a portion of the oxygene of nitro-muriatic acid, could produce -from it oxygenated muriatic acid, apparently mingled with very small -portions of any other gas. - -_d._ To ascertain whether any permanent gas was produced during the -ebullition of aqua regia, of the same composition as that used for the -solution of the platina; I kept a large quantity of it boiling for some -time, in communication with the water apparatus; the gas generated -appeared to be wholly nitro-muriatic, and was absorbed as fast as -produced, by the water. - -_e._ To determine whether any nitrous oxide was mingled with the -peculiar gas, as well as the nature and quantity of the unabsorbable -gas, nitrous gas was gradually added to 21 cubic inches of the gas -produced from a new solution, till the diminution was complete: the gas -remaining equalled 2,3 cubic inches; it was unabsorbable by water, and -extinguished flame. - -In another experiment, when the last portions of gas from a solution -were carefully received in water previously boiled, 12 cubic inches -agitated in water left a residuum of 1.3; whilst the same quantity -decomposed by nitrous gas, containing,02 nitrogene, left about 1.5. - -Hence it appeared that the aëriform products of the solution consisted -of the peculiar gas analogous to oxygenated muriatic acid, and of a -small quantity of nitrogene. - -_f._ Consequently a portion of the nitric acid of the aqua regia had -been decomposed; but if it had given oxygene both to the platina and -muriatic acid, the quantity of nitrogene evolved ought to have been -much more considerable. - -_g._ To ascertain if any water had been decomposed, and the nitrogene -condensed in the solution by its hydrogene, to form ammoniac, I -saturated a solution with lime, and heated it, but no ammoniacal smell -was perceived. - -_h._ To determine if any nitrogene had entered into chemical -combination with muriatic acid and oxygene, so as to form an aëriform -triple compound, analogous in its properties to oxygenated muriatic -acid, I exposed some of the gas to mercury, expecting that this -substance, by combining with its oxygene, would effect a complete -decomposition; and this was actually the case: for the gas was at -first rapidly diminished, and the mercury became oxydated; its volume, -however, soon increased; and the residual gas appeared to be nitrous, -mingled with much nitrogene. The exact proportions of each, from an -accident, I could not determine. - -This experiment was inconclusive, because the nitro-muriatic acid -suspended in the peculiar gas, from which it can probably be never -perfectly freed, acted in common with it upon the mercury, and produced -nitrous gas: and this nitrous gas, at the moment of its production, -formed nitrous acid by combining with the oxygene of the peculiar -gas; and the nitrous acid generated[149] was again decomposed by the -mercury; and hence nitrous gas evolved, and possibly some nitrogene. - -[149] The decomposition of aëriform nitrous acid by mercury, was first -noted by Priestley; vol. iii. pag. 101. This decomposition I have often -had occasion to observe. In reading Humbolt’s paper on eudiometry, -Annales de Chimie, xxviii, pag. 150, I was not a little surprised to -find that he takes no notice of this fact. He seems to suppose that -nitrous acid can remain aëriform, and even be condensed, in contact -with mercury, without alteration. He says, “In mingling 100 parts of -atmospheric air with 100 of nitrous air, the air immediately became -red, but all the acid produced remained aëriform; and after eighteen -hours some _drops_ only of acid were formed, which _swam_ upon the -mercury.” - -_i._ Peculiar circumstances prevented me at this time from completely -investigating the subject. It remains doubtful whether the gas consists -simply of highly oxygenated muriatic acid and nitrogene,[150] produced -by the decomposition of nitric acid from the coalescing affinities of -platina and muriatic acid for oxygene; or whether it is composed of a -_peculiar_ gas, analogous to oxygenated muriatic acid, and nitrogene, -generated from some unknown affinities.[151] - -[150] Lavoisier has said concerning aqua regia, “In solutions of metals -in this acid, as in all other acids, the metals are first oxydated, -by attracting a part of the oxygene from the compound radical. This -occasions the disengagement of a particular species of gas not hitherto -described, which may be called nitro-muriatic gas. It has a very -disagreeable smell, and is fatal to animal life when respired; it -attacks iron, and causes it to rust; it is absorbed in considerable -quantities by water.” Elem. Eng. 237. - -[151] I have no doubt but that the gas procured from the solution of -gold in aqua regia, is analogous to that produced from platina. - -Some very uncommon circumstances are attendant on the solution of -platina: - -1st. The immense quantity of acid required for the solution of a minute -quantity of platina. - -2d. The great quantity of gas produced during the solution of this -minute quantity. - -3d. The intense red color of the solution, and its perfectly acid -properties after it ceases to act upon the metal. - - -XI. _On the action of the Electric Spark on a mixture of Nitrogene and -Nitrous Gas._ - -Thinking it possible that nitrous gas and nitrogene might be made to -combine by the action of the electric spark, so as to form nitrous -oxide, I introduced 20 grain measures of each of them into a small -detonating tube, graduated to grains, standing over mercury, and -containing a very small quantity of cabbage juice rendered green by an -alkali. After electric sparks had been passed through the gases for an -hour and half, they were diminished to about 32, and the cabbage juice -was slightly reddened. On introducing about 10 measures of hydrogene, -and passing the electric spark through the whole, no inflammation or -diminution was perceptible. Hence the condensation most probably arose -wholly from the formation of nitrous acid,[152] by the more intimate -union of the oxygene of nitrous gas with some of its nitrogene, as in -the experiments of Priestley. - -[152] For if nitrous oxide had been formed, it would have been -decomposed by the hydrogene. - -As the nascent nitrogene, in the decomposition of nitrate of ammoniac, -combines with a portion of oxygene and nitrogene, to form nitrous -oxide; it is probable that nitrous oxide may be produced during the -passage of nitrous gas and ammoniac through a heated tube. - - -XII. _General Remarks._ - -There are no reasons for supposing that nitrous oxide is formed in any -of the processes of nature; and the nice equilibrium of affinity by -which it is constituted, forbids us to hope for the power of composing -it from its simple principles. We must be content to produce it, either -directly or indirectly, from the decomposition of nitric acid. And as -in the decomposition of nitrate of ammoniac, not only all the nitrogene -of the nitric acid enters into the composition of the nitrous oxide -produced, but likewise that of the ammoniac, this process is by far -the cheapest, as well as the most expeditious. A mode of producing -ammoniac at little expence, has been proposed by Mr. Watt. Condensed -in the sulphuric acid, it can be easily made to combine with nitric -acid, from the decomposition of nitre by double affinity. And thus, -if the hopes which the experiments at the end of those researches -induce us to indulge, do not prove fallacious, a substance which has -been heretofore almost exclusively appropriated to the destruction of -mankind, may become, in the hands of philosophy, a means of producing -health and pleasurable sensation. - - - - -RESEARCH II. - -INTO THE COMBINATIONS OF NITROUS OXIDE, AND ITS DECOMPOSITION BY -COMBUSTIBLE BODIES. - - -DIVISION I. - -_EXPERIMENTS and OBSERVATIONS on the COMBINATIONS of NITROUS OXIDE._ - - -I. _Combination of Water with Nitrous Oxide._ - -_a._ The discoverer of nitrous oxide first observed its solubility in -water; and it has since been noticed by different experimentalists. - -Dr. Priestley found that water dissolved about one half of its bulk -of nitrous oxide, and that at the temperature of ebullition, this -substance was incapable of remaining in combination with it.[153] - -[153] Experiments and observations, vol. ii. pag. 81. - -_b._ I introduced to 9 cubic inches of pure water, i. e. water -distilled under mercury, 7 cubic inches of nitrous oxide, which -had been obtained over mercury, from the decomposition of nitrate -of ammoniac, and in consequence was perfectly pure. After they had -remained together for 11 hours, temperature being 46°, during which -time they were frequently agitated, the gas remaining was 2,3; -consequently 4,7 cubic inches had been absorbed. And then, 100 cubic -inches, = 25300 grains of water, will absorb 54 cubic inches, = 27 -grains, of nitrous oxide. - -_c._ The taste of water impregnated with nitrous oxide, is distinctly -sweetish; it is softer than common water, and, in my opinion, much more -agreeable to the palate. It produces no alteration in vegetable blues, -and effects no change of color in metallic solutions. - -_d._ Thinking that water impregnated with nitrous oxide might probably -produce some effects when taken into the stomach, by giving out -its gas, I drank, in June, 1799, about 3 ounces of it, but without -perceiving any effects. - -A few days ago, considering this quantity as inadequate, I took at two -draughts nearly a pint, fully saturated; and at this time Mr. Joseph -Priestley drank the same quantity. - -We neither of us perceived any remarkable effects. - -Since that time I have drank near three pints of it in the course of a -day. In this instance it appeared to act as a diuretic, and I imagined -that it expedited digestion. As a matter of taste, I should always -prefer it to common water. - -_e._ Two cubic inches of pure water, that had been made to absorb -about 1,1 cubic inches of nitrous oxide; when kept for some time in -ebullition, and then rapidly cooled, produced nearly 1 of gas. Sulphur -burnt in this gas with a vivid rose-colored flame. - -In another experiment, in which the gas was expelled by heat from -impregnated water, and absorbed again after much agitation on cooling; -the residuum was hardly perceptible, and most likely depended upon some -gas which had adhered to the mercury, and was liberated during the -ebullition. Hence it appears that nitrous oxide is expelled unaltered -from its aqueous solution by heat. - -_f._ I have before mentioned, Division III, that nitrous oxide, during -its combination with spring water, expels the common air dissolved in -it. This common air generally amounts to one sixteenth, the volume of -the water being unity. A correction on account of this circumstance -must be made for the apparent deficiency of diminution, and for the -common air mingled in consequence, with nitrous oxide during its -absorption by common water. - -_g._ Water impregnated with nitrous gas absorbed nitrous oxide; but the -residual gas was much greater than that of common water, and gave red -fumes with atmospheric air. Nitrous gas agitated for a long while over -water highly impregnated with nitrous oxide, was not in the slightest -degree diminished, in one experiment indeed it was rather increased; -doubtless from the liberation of some nitrous oxide from the water by -the agitation. - -_h._ Nitrous oxide kept in contact with aqueous solution of sulphurated -hydrogene and often agitated, was not in the slightest degree -diminished. - -Sulphurated hydrogene, introduced into a solution of nitrous oxide, was -rapidly absorbed, and as the process advanced, the nitrous oxide was -given out. - -_i._ Water impregnated with carbonic acid, possessed no action upon -nitrous oxide, and did not in the slightest degree absorb it. When -carbonic acid was introduced to an aqueous solution of nitrous oxide; -the aëriform acid was absorbed, and the nitrous oxide liberated. - -_k._ From these observations it appears that nitrous oxide has less -affinity for water, than even the weaker acids, sulphurated hydrogene -and carbonic acid; as indeed one might have conjectured a priori from -its degree of solubility: likewise that it has a stronger attraction -for water than the gases not possessed of acid or alkaline properties; -it expelling from water nitrous gas, oxygene, and common air; probably -hydrocarbonate, hydrogene, and nitrogene. - - -II. _Combinations of Nitrous Oxide with Fluid Inflammable Bodies._ - -_a._ Vitriolic ether absorbs nitrous oxide in much larger quantities -than water. - -A cubic inch of ether, at temperature 52°, combined with a cubic inch -and seven tenths of nitrous oxide. - -Ether thus impregnated was not at all altered in its appearance; its -smell was precisely the same, but the taste appeared less pungent, and -more agreeable. Nitrous oxide is liberated unaltered from ether at a -very low temperature, that is, at about the boiling point of this fluid. - -For expelling nitrous oxide from impregnated ether, and for -ascertaining in general the quantity of gases combined with fluids, I -have lately made use of a very simple method, which it may not be amiss -to describe. - -The impregnated fluid is introduced into a small thin tube, graduated -to,05 cubic inches, through mercury. The quantity of fluid should never -equal more than a fifth or sixth of the capacity of the tube. - -The lower part of the tube is adapted to an orifice in the shelf of -the mercurial apparatus, so as to make an angle of about 40° with the -surface of the mercury. - -The flame of a small spirit lamp is then applied to that part of the -tube containing the fluid; and after the expulsion of the gas from it, -the heat is raised so as to drive out the fluid through the orifice of -the tube. Thus the liberated gas is preserved in a state proper for -accurate examination. - -Impregnated ether, during its combination with water, gives out the -greater part of its nitrous oxide. During the liberation of nitrous -oxide from ether, by its combination with water, a very curious -phænomenon takes place. - -If the water employed is colored, so that it may be seen in a stratum -distinct from the impregnated ether, at the point of contact a number -of small spherules of fluid will be perceived, apparently repulsive -both to water and ether; these spherules become gradually covered -with minute globules of gas, and as this gas is liberated from their -surfaces, they gradually disappear. - -_b._ Alcohol dissolves considerable quantities of nitrous oxide. - -2 cubic inches of alcohol, at 52°, combined with 2,4 cubic inches of -nitrous oxide. The alcohol thus impregnated had a taste rather sweeter -than before, but in other physical properties was not perceptibly -altered. - -Nitrous oxide is incapable of remaining in combination with this fluid -at the temperature of ebullition; it is liberated from it unaltered by -heat. - -Impregnated alcohol, during its combination with water, gives out -the greater part of its combined nitrous oxide: on mingling the two -fluids together, at the point of contact the alcohol becomes covered -with an infinite number of small globules of gas, which continue to be -generated during the whole of the combination, and in passing through -the fluid render it almost opaque. - -_c._ The essential oils absorb nitrous oxide to a greater extent than -either alcohol or ether. - -,5 cubic inches of oil of carui combined with 1,2 cubic inches of -nitrous oxide at 51°. The color of the oil thus impregnated was rather -paler than before. - -Nitrous oxide is expelled unaltered from impregnated oil of carui, by -heat. - -1 of oil of turpentine absorbed nearly 2 of nitrous oxide, at 57°. Its -properties were not sensibly altered from this combination, and the gas -was expelled from it undecompounded, by heat. - -_d._ As well as the essential oils, the fixed oils dissolve nitrous -oxide at low temperatures, whilst at high temperatures they do not -remain in combination. - -1 of olive oil absorbed, at 61°, 1,2 of nitrous oxide, but without -undergoing any apparent physical change. - - -III. _Action of Fluid Acids on Nitrous Oxide._ - -_a._ Nitrous oxide exposed to concentrated sulphuric acid, undergoes no -change, and suffers no diminution, that may not be accounted for from -the abstraction of a portion of its water by the acid. - -_b._ Nitrous oxide is scarcely at all soluble in nitrous acid, and -exposed to that substance, undergoes no alteration. - -_c._ Muriatic acid, of specific gravity 1,14 absorbs about a third -of its bulk of nitrous oxide. It suffers no apparent change in its -properties from being thus impregnated, and the gas is again given out -from it on the application of heat. - -_d._ Acetic acid absorbs nearly one third of its bulk of nitrous oxide. - -_e._ Aqua regia, that is, the nitro-muriatic acid, absorbs a very -minute portion of nitrous oxide. - -_f._ Nitrous oxide was exposed to a new compound acid, consisting of -oxygenated muriatic acid, and sulphuric acid, which I discovered in -July, 1799, and of which an account will be shortly published; but it -was neither absorbed or altered. - -I have before mentioned that the aqueous solutions of sulphurated -hydrogene and carbonic acid, neither dissolve or alter nitrous oxide. - - -IV. _Action of Saline Solutions, and other Substances, on Nitrous -Oxide._ - -_a._ Nitrous oxide exposed to concentrated solution of green sulphate -of iron, at 58°, underwent no perceptible diminution; not even after it -had been suffered to remain in contact with it for half an hour. - -_b._ It underwent diminution of nearly,2 when agitated in contact with -a solution of red sulphate of iron, the volume of the solution being -unity. - -_c._ Solution of green sulphate of iron, fully impregnated with nitrous -gas, did not in the slightest degree absorb nitrous oxide, and appeared -to have no action upon it. - -_d._ Solution of green muriate of iron, whether impregnated with -nitrous gas, or unimpregnated, has no affinity for, or action upon, -nitrous oxide. - -_e._ Solution of red muriate of iron in alcohol, absorbed nearly one -fifth of its bulk, of nitrous oxide. - -_f._ Solution of prussiate of potash absorbed nearly one third of its -volume, of nitrous oxide, which was again expelled from it by heat. - -_g._ Solution of nitrate of copper appeared to have no affinity for -nitrous oxide. - -_h._ Concentrated solution of nitrate of ammoniac, at 58°, absorbed one -eighth of its bulk of nitrous oxide. - -_i._ Solutions of alkaline sulphures absorb nitrous oxide in quantities -proportionable to the water they contain; it is expelled from them -unaltered by heat. None of the hydro-sulphures dissolve more than half -their bulk of nitrous oxide. - -_k._ Concentrated solutions of the sulphites possess little or -no action on nitrous oxide; diluted solutions absorb it in small -quantities. - -_l._ Concentrated solution of muriate of tin absorbs about one eighth -of nitrous oxide; more dilute solutions absorb larger quantities. - -From these observations we learn, that neutro-saline solutions in -general, have very feeble attractions for nitrous oxide; and as -solutions of green muriate, and sulphate of iron, whether free from -nitrous gas, or impregnated with it, possess no action upon nitrous -oxide, nitrous gas may be separated from this substance by those -solutions with greater facility than nitrous oxide can be separated -from nitrous gas, by water or alcohol. - -Charcoal absorbs nitrous oxide as well as all other gases; and it is -disengaged from it by heat. - -I have as yet found no other solid body, not possessed of alkaline -properties, capable of absorbing nitrous oxide in any state of -existence. - -The bodies possessing the strongest affinity for oxygene, the dry -sulphites, muriate of tin, the common sulphures, white prussiate of -potash, and green oxide of iron, do not in the slightest degree act on -nitrous oxide at common temperatures. - - -V. _Action of different Gases on Nitrous Oxide._ - -_a._ 12 measures of muriatic acid gas were mingled with 7 measures -of nitrous oxide at 56°. After remaining together for a minute, they -filled a space equal to 19½ measures. When water was introduced to -them, the muriatic acid was absorbed much more slowly than if it had -been unmingled. - -In another experiment, when the gases were saturated with water, 9 -measures of each of them, when mingled and suffered to remain in -contact for a quarter of an hour, filled a space nearly equal to 19; -and after the muriatic acid had been absorbed by potash, the nitrous -oxide remained unaltered in its properties. - -From the expansion, it appears most probable that aëriform muriatic -acid, and nitrous oxide, have a certain affinity for each other, and -that they combine when mingled together; for in the last experiment, -the increase of volume cannot be accounted for by supposing that -nitrous oxide undergoes less change of volume than muriatic acid, -by aëriform combination with water, and that the expansion depended -upon the solution of some of its combined water by the muriatic acid. -That muriatic acid and nitrous oxide have a slight affinity for each -other, likewise appears from the absorption of nitrous oxide by aqueous -solution of muriatic acid. - -Thinking that nitrous oxide might attract muriatic acid from its -solution in water, I exposed a minute quantity of fluid muriatic acid -to nitrous oxide; but no alteration of volume took place in the gas. - -_b._ 6 measures of nitrous oxide were mingled with 11 measures of -sulphureous acid, saturated with water; after remaining at rest for six -minutes, they filled a space nearly equal to 18 measures. Exposed to -water, the sulphureous acid was absorbed, but not nearly so rapidly as -when in a free state. Sulphur burnt with a vivid flame in the residual -nitrous oxide. 7 measures of sulphureous acid were now mingled with -8 of nitrous oxide. They filled a space nearly equal to 15¾, and no -farther expansion took place afterwards. - -From these experiments it appears probable that sulphureous acid, and -nitrous oxide, have some affinity for each other. - -_c._ 11 measures of carbonic acid were mingled with 8 of nitrous -oxide; they filled a space nearly equal to 19 measures. On exposing -the mixture to caustic potash, the carbonic acid was absorbed, and the -nitrous oxide remained pure. Hence it appears that carbonic acid and -nitrous oxide do not combine with each other. - -_d._ Oxygenated muriatic acid, and nitrous oxide, were mingled in a -water apparatus: there was a slight appearance of condensation; but -this was most probably owing to absorption by the water; on agitation, -the oxygenated muriatic acid was absorbed, and the greater part of the -nitrous oxide remained unaltered. - -_e._ Sulphurated hydrogene and nitrous oxide, mingled together, neither -expanded or contracted; exposed to solution of potash, the acid[154] -only was absorbed. - -[154] The experiments of Berthollet have clearly proved the perfect -acidity of this substance. - -_f._ 10 measures of nitrous gas were admitted to 12 of nitrous oxide at -59°. They filled a space equal to 22, and after remaining together for -an hour, had undergone no change. Solution of muriate of iron absorbed -the nitrous gas without affecting the nitrous oxide. - -_g._ Nitrous oxide was successively mingled with oxygene, atmospheric -air, hydrocarbonate, phosphorated hydrogene, hydrogene, and nitrogene, -at 57°; it appeared to possess no action on any of them, and was -separated by water, the gases remaining unaltered. - -_h._ As nitrous oxide was soluble in ether, alcohol, and the other -inflammable fluids, it was reasonable to suppose that its affinity for -those bodies would enable them to unite with it in the aëriform state. -At the suggestion of Dr. Beddoes I made the following experiment: - -To 12 measures of nitrous oxide, at 54°, I introduced a single drop of -ether; the gas immediately began to expand, and in four minutes filled -a space equal to sixteen measures and a quarter. When an inflamed taper -was plunged into the gas thus holding ether in solution, a light blue -flame slowly passed through it. - -A considerable diminution of temperature is most probably produced, -from the great expansion of nitrous oxide during its combination with -ether. - -A drop of alcohol was admitted to 14 measures of nitrous oxide. In five -minutes, the gas filled a space equal to fifteen and a third; but no -farther diminution took place afterwards. - -A minute quantity of oil of turpentine was introduced to 14 measures -of nitrous oxide; it filled, in 4 minutes, a space rather less than -14; and no farther change took place afterwards. Most likely this -contraction arose from the precipitation of the water dissolved in the -gas by the stronger affinity of the oil for nitrous oxide. To ascertain -with certainty if any oil had been dissolved by the gas, I introduced -into it a small quantity of ammoniac. It immediately became slightly -clouded, most probably from the formation of soap, by the combination -of the dissolved oil with the ammoniac. - -From these experiments we learn, that when nitrous oxide is mingled -with either carbonic acid, oxygene, common air, hydrocarbonate, -sulphurated hydrogene, hydrogene, or nitrogene, they may be separated -from each other without making any allowance for contraction or -expansion; but if a mixture of either muriatic acid, or sulphureous -acid gas, with nitrous oxide, is experimented upon; in the absorption -of the acid by alkalies, the apparent volume of gas condensed will be -less than the real one, by a quantity equal to the sum of expansion -from combination. Consequently a correction must be made on account of -this circumstance. - -Though alcohol, ether, essential oils, and the fluid inflammable -bodies in general, dissolve nitrous oxide with much greater rapidity -than water, yet as we are not perfectly acquainted with their action on -unabsorbable gases, it is better to employ water for separating nitrous -oxide from these substances; particularly as that fluid is more or less -combined with all gases, and as we are acquainted with the extent of -its action upon them. - -By pursuing the subject of the solution of essential oils in gases, -we may probably discover a mode of obtaining them in a state of -absolute dryness. For if other gases as well as nitrous oxide, have a -stronger affinity for oils than for water, water most probably will -be precipitated from them during their solution of oils; and after -their saturation with oil, it is likely that they are capable of being -deprived of that substance by ammoniac. - - -VI. _Action of aëriform Nitrous Oxide in the Alkalies. History of the -discovery of the combinations of Nitrous Oxide with the Alkalies._ - -_a._ When nitrous oxide in a free state is exposed to the solid caustic -alkalies and alkaline earths, at common temperatures, it is neither -absorbed nor acted upon; when it is placed in contact with solutions -of them in water, a small quantity is dissolved; but this combination -appears to depend on the water of the solution, for the gas can be -expelled unaltered, at the temperature of ebullition. - -_b._ Caustic potash was exposed to nitrous oxide for 13 hours: the -diminution was not to one fiftieth, and this slight condensation most -probably depended upon its combination with the water of the gas. - -Concentrated solution of potash absorbed a fourth of its bulk of -nitrous oxide. When the impregnated solution was heated, globules of -gas were given out from it rapidly; but the quantity collected was too -small to examine. - -Soda, whether solid or in solution, exhibited exactly the same -phænomena with nitrous oxide. The solution of soda absorbed near a -quarter of its bulk of gas. - -_c._ 11 measures of ammoniacal gas were mingled with 8 measures of -nitrous oxide over dry mercury, both of the gases being saturated with -water. No change of appearance was produced by the mixture, and they -filled, after two minutes, a space equal to 19. On the introduction -of a little water, the ammoniac was absorbed, and the nitrous oxide -remained unaltered, for it was dissolved by water as rapidly as if it -had never been mingled with ammoniac.[155] - -[155] The Dutch chemists have asserted, that mixture with ammoniac -prevents the absorption of nitrous oxide by water, either wholly or -partially. Journal de Physique, t. xliii. part ii. pag. 327. It is -difficult to account for their mistake. - -7 measures of nitrous oxide, exposed to 6 measures of solution of -ammoniac in water, was in an hour diminished to 4½ nearly. When the -solution was heated over mercury, permanent gas was produced, which -was unabsorbable by a minute quantity of water, and soluble in a large -quantity; consequently it was nitrous oxide. - -_d._ Nitrous oxide was exposed to dry caustic strontian; it underwent a -diminution of nearly one fortieth, which most likely was owing to the -combination of the strontian with its water. - -11 measures of nitrous oxide were agitated in contact with 8 of -strontian lime water: nearly 4 measures were absorbed. The impregnated -solution exposed to heat, rapidly gave out its gas; 3 measures were -soon collected, which mingled with a small quantity of hydrogene, and -inflamed by the taper, gave a smart detonation. - -_e._ Nitrous oxide exposed to lime and argil, both wet and dry, was not -in the slightest degree acted upon. - -From these experiments it is evident that nitrous oxide in the aëriform -state cannot be combined either with the alkalies, or the alkaline -earths. That a combination may be effected between nitrous oxide and -these substances, it must be presented to them, in the _nascent state_. - -The salts composed of the alkalies and nitrous oxide, are not -analogous to any other compound substances, being possessed of very -singular properties. Before these properties are detailed, it may not -be amiss to give an account of the accidental way in which I discovered -the mode of combination. - -In December, 1799, designing to make a very delicate experiment, with -a view to ascertain if any water was decomposed during the conversion -of nitrous gas into nitrous oxide, by sulphite of potash, I exposed -200 grains of crystalised sulphite of potash, containing great -superabundance of alkali, to 14 cubic inches of nitrous gas, containing -one eighteenth nitrogene. The alkali was employed to preserve any -ammoniac that might be formed, in the free state, as it would otherwise -combine with sulphureous acid.[156] - -[156] Sulphureous acid saturates more potash than sulphuric acid, so -that most probably during the conversion of sulphite of potash into -sulphate, portions of sulphureous acid are disengaged. - -The volume of gas diminished with great rapidity; in two hours and -ten minutes it was reduced to 6⁴/₅, which I considered as the limit -of diminution. Accidentally, however, suffering it to remain for three -hours longer, I was much surprised by finding that not quite 2 cubic -inches remained, which consisted of nitrous oxide, mingled with the -nitrogene that existed before the experiment. - -In accounting theoretically for this phænomenon, different suppositions -necessarily presented themselves. - -1st, It was possible, that though sulphite of potash, and potash, -separately possessed no action on free nitrous oxide, yet in -combination they might exert such affinities upon it as either to -absorb it, or make it enter into new combinations. - -2dly. It was more probable that the caustic potash, though incapable -of condensing aëriform nitrous oxide, was yet possessed of a strong -affinity for it when in the _nascent state_, and that the nitrous oxide -condensed in the experiment had been combined in this state with the -free alkali. - -To ascertain if the compound of potash and sulphite of potash with -sulphate, was capable of acting upon nitrous oxide, I suffered a -quantity of this substance to remain in contact with the gas for near a -day: no change whatever took place. - -To determine whether the diminution of nitrous oxide depended upon its -absorption in the nascent state, by the peculiar compound of potash and -sulphite of potash, or if it was simply owing to the alkali. - -I mingled a solution of sulphite of potash with caustic soda; the -salt, after being evaporated at a low temperature, was exposed to -nitrous gas. The nitrous oxide formed was absorbed, but in rather less -quantities than when alkaline sulphite of potash was employed. - -Hence it was evident that the alkali was the agent that had condensed -the nitrous oxide in those experiments, for soda is incapable of -combining either with sulphate, or sulphite of potash. - -To ascertain whether any change in the constitution of the nitrous -oxide had been produced by the condensation, I introduced a small -quantity of sulphite of potash, with excess of alkali, that had -absorbed nitrous oxide, into a long and thin cylindrical tube filled -with mercury; and inclining it at an angle of 35° with the plane of the -mercury, applied the heat of a spirit lamp to that part of the tube -containing the salts; when the glass became very hot, gas was given out -with rapidity; in less than a minute the tube was full. This gas was -transfered into another tube, and examined; it proved to be nitrous -oxide in its highest state of purity;[157] for a portion of it absorbed -by common water, left no more than a residuum of ¹/₁₅, and sulphur -burnt in it with a vivid rose-colored flame. - -[157] Hence we learn that sulphite of potash, when strongly heated, -does not decompose nitrous oxide, even in the _nascent state_. - -Being now satisfied that the alkalies were capable of combining with -nitrous oxide; to investigate with precision the nature of these new -compounds, I proceeded in the following manner. - - -VII. _Combination of Nitrous Oxide with Potash._ - -_a._ Into a solution of sulphite of potash, which had been made by -passing sulphureous acid gas from a mercurial airholder into caustic -potash dissolved in water, I introduced 17 grains of dry potash. The -whole evaporated at a low temperature, gave 143 grains of salt. This -salt was not _wholly_ composed of sulphite of potash and potash; it -contained as well, a minute quantity of carbonate, and sulphate of -potash, formed during the evaporation.[158] - -[158] See the excellent memoir of Fourcroy and Vauquelin on the -sulphureous acid, and its combinations. Annales de Chimie, ii, 54. Or -Nicholson’s Phil. Journal, vol. i, pag. 313. - -120 grains of it finely pulverised, and retaining the water of -crystalisation, were exposed to 15 cubic inches of nitrous gas, over -mercury. The nitrous gas diminished with great rapidity, and in three -hours a cubic inch and nine tenths only remained, which consisted of -nearly one third nitrous oxide, and two thirds nitrogene that had -pre-existed in the nitrous gas. The increase of weight of the salt -could not be determined, as some of it was lost by adhering to the -vessel in which the combination was effected, and to the mercury. It -presented no distinct series of crystalisations, even when examined -by the magnifier; rendered green vegetable blues, and its taste was -very different from that of the remaining quantity of salt that had -been exposed to the atmosphere. A portion of it strongly heated over -mercury, gave out gas with great rapidity, which had all the properties -of the purest nitrous oxide. - -When water was poured upon some of it, no gas was given out, and the -whole was equably and gradually dissolved. Alcohol, as well as ether, -appeared incapable of dissolving any part of it. - -When muriatic acid was introduced into it, confined by mercury, a rapid -effervescence took place. Part of the gas disengaged was sulphureous -acid, and carbonic acid; the remainder was nitrous oxide. - -_b._ I made a number of experiments upon salts procured in the manner -I have just described, with a view to obtain the compound of nitrous -oxide and potash, free from admixture of other salts. - -When the mixed salt was boiled in alcohol or ether, no part of it -appeared to be dissolved. Finding that little or no gas was given out -during the ebullition of concentrated solutions of the mixed salts, -I attempted to separate the sulphate, sulphite, and carbonate of -potash, from the combination of nitrous oxide and potash, by successive -evaporations and crystalisations. But though in this way it was nearly -freed from sulphate of potash, yet the extreme and nearly equal -solubility of the other salts, prevented me from completely separating -them from each other. - -By exposing, however, very finely pulverised sulphite of potash, -mingled with alkali, for a great length of time to nitrous gas, it was -almost wholly converted into sulphate; and after the separation of -this solution, evaporation, and crystalisation, at a low temperature, -I obtained the new combination, mingled with very little carbonate of -potash, and still less of sulphite. - -The minute quantity of sulphite chiefly appeared in very small -crystals; distinct from the mass of salt, which possessed no regular -crystalisation, and was almost wholly composed of the new compound, -intimated mingled with a little carbonate. The new compound, as nearly -as I could estimate from the quantity of nitrous oxide absorbed, -consisted of about 3 alkali, to 1 of nitrous oxide, by weight. - -It exhibited the following properties: - -1. Its taste was caustic, and possessed of a pungency different from -either potash or carbonate of potash. - -2. It rendered vegetable blues green, which might possibly depend upon -the carbonate of potash mixed with it. - -3. Pulverised charcoal mingled with a few grains of it, and inflamed, -burnt with flight scintillations. Projected into zinc in a state of -fusion, a slight inflammation was produced. - -4. When either sulphuric, muriatic, or nitric acid was introduced to -it under mercury, it gave out nitrous oxide, mingled with a little -carbonic acid. - -5. Thrown into a solution of sulphurated hydrogene, gas was disengaged -from it, but in quantities too minute to be examined. - -6. When carbonic acid was thrown into a solution of it in water, gas -was disengaged; on examination it proved to be nitrous oxide. - -7. A concentrated solution of it kept in ebullition in a cylinder, -confined by mercury, gave out a few globules of gas, which were too -minute to be examined, and probably consisted of common air previously -contained in the water. - -_c._ In the experiments made to ascertain these properties all the salt -was expended, otherwise I should have endeavoured to ascertain what -quantity of gas would have been liberated by heat from a given weight; -and likewise what would have been the effects of admixture of it with -oil. When some of the mixed salt was mingled with oil of turpentine, -part of it was dissolved, and the fluid became white; but no gas was -given out. On this coarse experiment, however, I cannot place much -dependance. If the combination of nitrous oxide and potash is capable -of combining with oil without decomposition, barytes and strontian[159] -will probably separate the oil from it, and thus it may possibly be -obtained in a state of purity. - -[159] Unless the sum of affinity of the potash, oil, nitrous oxide, and -earths, should be inch as to enable the nitrous oxide to combine with -the earth, whilst the oil and alkali remained in combination, & c. - -In a rough experiment made on the conversion of nitrous gas into -nitrous oxide, by concentrated solution of sulphite of potash with -excess of alkali, very little of the nitrous oxide was absorbed. Hence -it is probable that water lessens the affinity of potash for nascent -nitrous oxide. - - -VIII. _Combination of Nitrous Oxide with Soda._ - -The union of nitrous oxide with soda is effected in the same manner -as with potash. The alkali, mingled by solution and evaporation, with -either sulphite of soda, or of potash, is exposed to nitrous gas; the -nitrous oxide is condensed by it at the moment of generation, and the -combination effected. - -As far as I have been able to observe, nitrous oxide is not absorbed to -so great an extent by soda, as potash. - -I have not yet been able to obtain the combination of nitrous -oxide with soda in its pure state. To the attainment of this end, -difficulties identical with those noticed in the last section present -themselves. It is extremely difficult to procure the soda perfectly -free from carbonic acid, and though by using sulphite of potash the -sulphate formed is easily separated, yet still evaporation and -crystalisation will not disengage the sulphite and carbonate from the -new compound. - -The compound of soda and nitrous oxide, mingled with a little sulphite -and carbonate of soda, was rapidly soluble, both in warm and cold -water, without effervescence. Its solution, heated to ebullition, gave -out no gas. The taste of the solid salt was caustic, and more acrid -than that of the mixture of carbonate and sulphite of soda. When cast -upon zinc in fusion, it burnt with a white flame. When heated to 400° -or 500°, it gave out nitrous oxide with rapidity. Nitrous oxide was -expelled from it by the sulphuric, muriatic, and carbonic acids, _I -believe_, by sulphurated hydrogene.[160] - -[160] For when a little of the mixed salt was introduced into a -solution of sulphurated hydrogene, globules of gas were given out -during the solution. - - -IX. _Combination of Nitrous Oxide with Ammoniac._ - -I attempted to effect this combination by converting nitrous gas into -nitrous oxide, by sulphite of ammoniac, wetted with strong solution of -caustic ammoniac; but without success; for the whole of the nitrous -oxide produced remained in a free state. - -When I exposed sulphite of potash, mingled by solution and evaporation -with highly alkaline carbonate of ammoniac,[161] to nitrous gas, the -diminution was nearly one fourth more than if pure sulphite of potash -had been employed. Hence it appears most likely that ammoniac is -capable of combination with nitrous oxide in the nascent state. - -[161] Carbonate of ammoniac formed at a high temperature, containing -near 60 per cent alkali, and capable of combining with small quantities -of acids without giving out its carbonic acid. Of this salt a -particular account will be given in the experiments on the ammoniacal -salts, which I have often mentioned in the course of this work. - -In the experiments on the conversion of nitrous gas into nitrous oxide, -by nascent hydrogene, and by sulphurated hydrogene, Res. I. Divis. -V. probably the water formed at the same time with the ammoniac -and nitrous oxide, prevented them from entering into combination; -_possibly_ the peculiar compound was formed, but in quantities so -minute as not to be distinguished from simple ammoniac;[162] for even -the existence of ammoniac in these processes, is but barely perceptible. - -If it should be proved by future experiments, that in the decomposition -of nitrous gas by nascent hydrogene, a peculiar compound of nitrous -oxide, water and ammoniac, is formed, it will afford proofs in favor of -the doctrine of predisposing affinity;[163] for then this decomposition -might be supposed to depend upon the disposition of oxygene, hydrogene -and nitrogene to assume the states of combination in which they might -form a triple compound, of water, nitrous oxide, and ammoniac. - -[162] It may not be amiss to mention some appearances taking place in -the decomposition of nitrous gas by sulphurated hydrogene, though it -is useless to theorise concerning them. The sulphur deposited is at -first yellow; as the process proceeds, it becomes white, and in some -instances I have suspected a diminution of it. - -[163] Predisposing affinity, the existence of which at first -consideration it is difficult to admit, may be easily accounted for -by _supposing_ the attractions of the simple principles of compound -substances. And this doctrine will apply in all instances where the -constitution of bodies is known. Predisposing affinity ought not to be -considered as the affinity of _non-existing_ bodies for each other; but -as the mutual affinity of their simple principles, disposing them to -assume new arrangements. - -Nitrous oxide might probably be made to combine with ammoniac by -exposing a mixture of nitrous gas and aëriform ammoniac, to the -sulphites. - -It is probable that nitrous oxide may be combined with ammoniac, -by means of double affinity. Perhaps sulphate of ammoniac and the -combination of potash with nitrous oxide mingled together in solution, -would be converted into sulphate of potash and the compound of nitrous -oxide, and ammoniac. - - -X. _Probability of forming Compounds of Nitrous Oxide and the Alkaline -Earths._ - -I attempted to combine nitrous oxide with lime and strontian, by -exposing sulphites of lime and strontian with excess of earth, to -nitrous gas; but this process did not succeed: the diminution took -place so slowly as to destroy all hopes of gaining any results in -a definite time. Sulphite of potash is decomposable by barytes, -strontian, and lime;[164] consequently it was impossible to employ this -substance to effect the combination. - -As the dry sulphures, when well made, convert nitrous gas into nitrous -oxide, it is probable that the union of the earths with nascent nitrous -oxide may be effected by exposing nitrous gas to their sulphures, -containing an excess of earth. - -[164] See the above mentioned elaborate memoir of Fourcroy and -Vauquelin. - -Perhaps the combination of nitrous oxide with strontian may be effected -by introducing the combination of potash and nitrous oxide into -strontian lime water. - -It is probable that nitrous oxide may be combined with clay and -magnesia, by exposing these bodies, mingled with sulphite of potash or -soda, to nitrous gas. - - -XI. _Additional Observations on the combinations of Nitrous Oxide with -the Alkalies._ - -A desire to complete physiological investigations relating to nitrous -oxide, has hitherto prevented me from pursuing to a greater extent, the -experiments on the combination of this substance with the alkalies, &c. -As soon as an opportunity occurs, I purpose to resume the subject. - -The observations detailed in the foregoing sections are sufficient to -show that nitrous oxide is capable of entering into intimate union -with the fixed alkalies: and as the compounds formed by this union -are insoluble in alcohol, decomposable by the acids, and heat, and -possessed of peculiar properties, they ought to be considered as a new -class of saline substances. - -If it is thought proper, on a farther investigation of their -properties, to signify them by specific names, they may, according to -the usually adopted fashion of nomenclature, be called _nitroxis_: -thus the _nitroxi of potash_ would signify the salt formed by the -combination of nitrous oxide with potash. - -Future experiments must determine the different affinities of nitrous -oxide for the alkalies, and alkaline earths. - -With regard to the uses of these new compounds it is difficult to -form a guess. When they are obtained pure, and fully saturated with -nitrous oxide, on account of the low temperature at which their gas is -liberated, they will probably constitute detonating compounds. From -their facility of decomposition by the weaker acids, they may possibly -be used medicinally, if ever the evolution of nitrous oxide in the -stomach should be found beneficial in diseases. - - -XII. _The properties of Nitrous Oxide resemble those of Acids._ - -If we were inclined to generalise, and to place nitrous oxide among -a known class of bodies, its properties would certainly induce us -to consider it as more analogous to the acids than to any other -substances; for it is capable of uniting with water and the alkalies, -and is insoluble in most of the acids. It differs, however, from the -stronger acids, in not possessing the sour taste,[165] and the power -of reddening vegetable blues: and from both the stronger and weaker -acids, in not being combinable when in a perfectly free state, at -common temperatures, with the alkalies. If it should be proved by -future experiments, that condensation by cold gave it the capability of -immediately forming neutro-saline compounds with the alkalies; it ought -to be considered as the weakest of the acids. Till those experiments -are made, its extraordinary chemical and physiological properties are -sufficient to induce us to consider it as a body _sui generis_. - -[165] The different persons who have respired nitrous oxide have, as -will be seen hereafter, given different accounts of the taste; the -greater number have called it sweet, some metallic. One of my friends, -in a letter to me dated Nov. 13, 1799, containing a detail of some -experiments made on the respiration of nitrous oxide, at Birmingham, -denotes the taste of it by the term “sweetish faintly acidulous.” To -me the taste both of the gas and of its solution in water, has always -appeared faintly sweetish. - -It is a singular fact that nitrous gas, which contains in its -composition a quantity of oxygene so much greater than nitrous oxide, -should nevertheless possess no acid properties. It is uncombinable with -alkalies, very little soluble in water, and absorbable by the acids. - - -DIVISION II. - - _On the DECOMPOSITION of NITROUS OXIDE by COMBUSTIBLE - BODIES. Its ANALYSIS. OBSERVATIONS on the different - combinations of OXYGENE and NITROGENE._ - - -I. _Preliminaries._ - -From the phænomena mentioned in Res. I. Divis. III.[166] it appears -that the combustible bodies burn in nitrous oxide at certain -temperatures. The experiments in this Division were instituted for the -purpose of investigating the precise nature of these combustions, with -a view of ascertaining exactly the composition of nitrous oxide. - -[166] Section 2. - -It will be seen hereafter that very high temperatures are required for -the decomposition of nitrous oxide, by most of the combustible bodies, -and that in this process heat and light are produced to a very great -extent. These agents alone are possessed of a considerable power of -action on nitrous oxide; of which it is necessary to give an account, -that we may be able to understand the phænomena in the following -sections. - - -II. _Conversion of Nitrous Oxide into Nitrous Acid, and a Gas analogous -to Atmospheric Air, by Ignition._ - -_a._ Dr. Priestley asserts, that nitrous oxide exposed for a certain -time to the action of the electric spark, is rendered immiscible with -water, and capable of diminution with nitrous gas, without suffering -any alteration of volume; and likewise that the same changes are -effected in it by exposure to ignited incombustible bodies.[167] - -[167] Vol. ii. pag. 91. - -The Dutch chemists state, that the electric spark passed through -nitrous oxide, occasions a small diminution of its volume, and that the -gas remaining is analogous to common air.[168] They conclude that this -change depends on the separation of its constituent parts, oxygene and -nitrogene, from each other. - -[168] Journal de Physique, tom. xliii, part ii. pag. 330. They effected -the same change by passing it through a heated tube. Dr. Priestley had -published an account of similar experiments more than two years before. - -None of these chemists have suspected the production of nitrous acid in -this process. - -_b._ Nitrous oxide undergoes no change whatever from the simple action -of light. I exposed some of it, confined by mercury, for many days to -this agent, often passing through it concentrated rays by means of a -small lens. When examined it appeared, as well as I could estimate, of -the same degree of purity as at the beginning of the experiment. - -_c._ A temperature below that of ignition effects no alteration in the -constitution of nitrous oxide. I passed nitrous oxide from a retort -containing decomposing nitrate of ammoniac, through a green glass -tube, strongly heated in an air-furnace, but not suffered to undergo -ignition. The gas, received in a water apparatus exhibited the same -properties as the purest nitrous oxide; some of it absorbed by water, -left a residuum of not quite one thirteenth. - -_d._ The action of the electric spark for a long while continued, -converts nitrous oxide into a gas analogous to atmospheric air, and -nitrous acid. - -I passed about 150 strong shocks from a small Leyden phial, through 7 -ten grain measures of pure nitrous oxide. After this it filled a space -rather less than six measures: the mercury was rendered white on the -top, as if it had been acted on by nitric acid. Six measures of nitrous -gas mingled with the residual gas of the experiment, over mercury -covered by a little water, gave red fumes, and rapid diminution. In -five minutes the volume of the gases nearly equalled ten. Thermometer -in this experiment was 58°. - -Electric sparks were passed for an hour and half through 7 ten grain -measures of nitrous oxide over mercury covered with a little red -cabbage juice, previously saturated with nitrous oxide, and rendered -green by an alkali. After the process the gas filled a space equal -to rather more than six measures and half, and the juice was become -of a pale red. The gas was introduced into a small tube filled with -pure water, and agitated; no absorption was perceptible: 7 measures -of nitrous gas added to it gave red fumes, and after six minutes a -diminution to 9¼ nearly. 6½ measures of common air from the garden, -with 7 of nitrous gas, gave exactly 9. - -In this experiment it was evident that nitrous oxide was converted into -a gas analogous to atmospheric air, at the same time that an acid was -formed. There could be little doubt but that this was the nitrous acid. -To ascertain it, however, with greater certainty, the electric spark -was passed through 6 measures of nitrous oxide, over a little solution -of green sulphate of iron, confined by mercury. As the process went on, -the color of the solution became rather darker. When the diminution -was complete, a little prussiate of iron was added to the solution. A -precipitate of pale blue prussiate of potash was produced. - -_c._ Nitrous oxide was passed from decomposing nitrate of ammoniac, -through a porcelain tube well glazed inside and outside, strongly -ignited in an air-furnace, and communicating with the water apparatus. -The gas collected was rendered opaque by dense red vapor. It appeared -wholly unabsorbable by water. After the precipitation of its vapor, a -candle burnt in it with nearly the same brilliancy as in atmospheric -air. 20 measures of it that had been agitated in water immediately -after its production, mingled with 40 measures of nitrous gas, -diminished to about 47.5; whereas 20 measures that had remained -unagitated for some time after their generation, introduced to the same -quantity of nitrous gas, gave nearly 49. 20 measures of atmospheric -air, with 40 of the same nitrous gas, were condensed to 46. - -The water with which the gas had been in contact, was strongly acid. A -little of it poured into a solution of green sulphate of iron, and then -mingled with prussian alkali, produced a green precipitate. Hence the -acid it contained was evidently nitrous. - -That no source of error could have existed in this experiment from -fissure in the tube, I proved, by sending water through it whilst -ignited, after the process, from the same retort in which the nitrate -of ammoniac had been decomposed; a few globules of air only were -produced, not equal to one tenth of the volume of the water boiled, and -which were doubtless previously contained in it. - -I have repeated this experiment two or three times, with similar -results; whenever the air was agitated in water immediately after its -production, it gave _almost_ the same diminution with nitrous gas as -common air; when, on the contrary, it has been suffered to remain for -some time in contact with the phlogisticated nitrous acid suspended -in it, the condensation has been less with nitrous gas by five or -six hundred parts. Hence I am inclined to believe, that if it were -possible to condense all the nitrous acid formed, immediately after -its generation, so as to prevent it from absorbing oxygene from the -permanent gas, this gas would be found identical with the air of the -atmosphere. - -The changes effected by fire on nitrous oxide are not analogous to -those produced by it in other bodies; for the power of this agent -seems generally _uniform_, either in wholly separating the constituent -principles of bodies from each other, or in making them enter into more -intimate union.[169] - -[169] On the one hand, it decomposes ammoniac into hydrogene and -nitrogene, whilst on the other, it converts free oxygene and nitrogene -into nitrous acid. It likewise converts nitrous gas into nitrous acid -and nitrogene. Till we are more accurately acquainted with the nature -of heat, light, and electricity, we shall probably be unable to explain -these phænomena. - -It is a singular phænomenon, that whilst it condenses one part of the -oxygene and nitrogene of nitrous oxide, in the form of nitrous acid; -it should cause the remainder to expand, in the state of atmospheric -air. Does not this fact afford an inference in favor of the _chemical_ -composition of atmospheric air? - - -III. _Decomposition of Nitrous Oxide by Hydrogene, at the temperature -of Ignition._ - -In the following experiments on the decomposition of nitrous oxide -by hydrogene, the gases were carefully generated in the mercurial -apparatus, and their purity ascertained by the tests mentioned in -Research I. They were measured in small tubes graduated to grains, and -then transferred into the detonating tube, which was eight tenths of an -inch in diameter, and graduated to ten grain measures. - -The space occupied by the gases being noted after the inflammation by -the electric shock, green muriate of iron, and prussiate of potash, -were successively introduced, to ascertain if any nitrous acid had -been formed. The absorption, if any took place, was marked, and the -gases transferred into a narrow grain measure tube, and their bulk and -composition accurately ascertained. - -_b._ The hydrogene employed was procured from water by means of zinc -and sulphuric acid. 50 grain measures of it fired by the electric -spark, with 30 grain measures of oxygene containing one eleventh -nitrogene, gave a residuum of about 4. Nitrous gas mingled with those -4, indicated the presence of rather less than 1 of unconsumed oxygene. -In another experiment 23 of it, with 20 of the same oxygene left rather -more than 6 residuum. - -The nitrous oxide was apparently pure, for it left a remainder of about -,05 only, when absorbed by common water. - -_c._ 30 of hydrogene were fired with 40 of nitrous oxide; the -concussion was very great, and the light given out bright red; no -perceptible quantity of nitrous acid was formed; the residual gas -filled a space equal to 52. No part of it was absorbable by water, it -gave no diminution with nitrous gas, when it was mingled with a little -oxygene, and again acted on by the electric spark, an inflammation and -slight diminution was produced. - -_d._ 33 of hydrogene were fired with 35 of nitrous oxide: nitrous acid -was produced in very minute quantity; the gas that remained was not -absorbable by water, and filled a space equal to 37 grains. Nitrous gas -mingled with these, underwent a very slight diminution. - -_e._ 46 hydrogene were fired with 46 nitrous oxide. The quantity of -nitrous acid formed was just sufficient to tinge the white prussiate -of potash. The gases filled a space equal to 49, gave no perceptible -diminution with nitrous gas, and did not inflame with oxygene. - -_f._ 40 hydrogene were fired with 39 nitrous oxide; no perceptible -quantity of nitrous acid was formed. The residual gas filled a space -equal to 41; was unabsorbable by water, underwent no diminution when -mingled with nitrous gas; or when acted on by the electric spark in -contact with oxygene. - -_g._ 20 hydrogene were fired with 64 nitrous oxide; after detonation -the expansion of the gases was greater in this experiment than any of -the preceding ones; dense white fumes were observed in the cylinder, -and a slow contraction of volume took place. After a little green -muriate of iron had been admitted, the gases filled a space equal -to 73: prussiate of potash mingled with the muriate, gave a deeper -blue than in any of the preceding experiments. The residual gas was -unabsorbable by water: 65 of it, mingled with 65 of nitrous gas, -diminished to 93; whilst 65 of common air, with 65 of nitrous gas, gave -84. - -_h._ 8 of hydrogene were fired with 54 of nitrous oxide; the same -phænomena as were observed in the last experiment took place; nitrous -acid was formed; after the absorption of which the residual gas filled -a space equal to 55. 50 of this, with an equal quantity of nitrous gas, -diminished to 76. In these processes the temperatures were from 56° to -61°. - -These experiments are selected as the most accurate of nearly fifty, -made on the inflammation of different quantities of nitrous oxide and -hydrogene. - -As Mr. Keir found muriatic acid in the fluid, produced by the -inflammation of oxygene and hydrogene in closed vessels, in Dr. -Priestley’s experiments, I preserved the residual gas of about 3 cubic -inches of nitrous oxide, that had been detonated at different times -with less than a cubic inch and half of hydrogene; but solution of -nitrate of silver was not clouded when agitated in this gas, nor when -introduced into the detonating tube in which the inflammation had been -made. - -From these experiments we learn that nitrous oxide is decomposable at -the heat of ignition, by hydrogene, in a variety of proportions. - -When the quantity of hydrogene very little exceeds that of the nitrous -oxide, both of the gates disappear, water is produced, no nitrous acid -is formed, and the volume of nitrogene evolved is rather greater than -that of the nitrous oxide decomposed. - -When the quantity of hydrogene is less than that of the nitrous oxide, -water, nitrous acid, oxygene and nitrogene, are generated in different -proportions; one part of the nitrous oxide is most probably wholly -decomposed by the hydrogene, and the other part converted into nitrous -acid and atmospheric air, in consequence of the ignition. - -From experiments _c_, _d_, and _e_, the composition of nitrous oxide -may be deduced. In experiment _d_, 39 of nitrous oxide were decomposed -by 40 of hydrogene, and converted into 41 of nitrogene. - -Now from _b_ it appears that 40 of hydrogene require for their -condensation about 20.8 of oxygene in volume; so that founding the -estimation upon the quantity of hydrogene consumed, 100 parts of -nitrous oxide would consist nearly of 63.1 of nitrogene, and 36.9 of -oxygene. But 41 of nitrogene weigh 12.4, Res. I. Div. I. Consequently, -deducing the composition of nitrous oxide from the quantity of -nitrogene evolved, 100 parts of it would consist of 63.5 nitrogene, and -36.5 oxygene. - -These estimations are very little different from those which may be -deduced from the other experiments, and the coincidence is in favor of -their accuracy. - -From the following experiment it appears that the temperature required -for the decomposition of nitrous oxide by hydrogene must be higher -than that which is necessary to produce the inflammation of hydrogene -with oxygene. I introduced into small tubes filled with equal parts of -nitrous oxide and hydrogene, standing on a surface of mercury, iron -wires ignited to different degrees, from the dull red to the vivid -white heat. The gases were always inflamed by the white and vivid -red heats; but never by the dull red heat, though the last uniformly -inflamed mixtures of oxygene and hydrogene, and atmospheric air and -hydrogene. - -Dr. Priestley[170] first detonated together nitrous oxide and -hydrogene; his experiment was repeated by the Dutch chemists, who found -that when a small quantity of hydrogene was employed, the nitrous -oxide was partially converted into a gas analogous to common air. Their -estimation of its composition, which is not far removed from the truth, -was founded on this phænomenon.[171] - -[170] Vol. ii. pag. 83. - -[171] Journal de Physique, tom. xliii. part 2, pag. 331. They supposed -it to consist of about 37,5 oxygene, and 62,5 nitrogene. The nearness -of this account to the truth is singular, when we consider that they -were neither acquainted with the specific gravity of nitrous oxide, nor -with the production of nitrous acid in this experiment. - - -IV. _Decomposition of Nitrous Oxide by Phosphorus._ - -_a._ Phosphorus introduced into pure nitrous oxide at common -temperatures, is not at all luminous. It is capable of being fused, -and even sublimed in it, without undergoing acidification, and without -effecting any alteration in its composition. - -About 2 grains of phosphorus were fused, and gradually sublimed, in 2 -cubic inches of pure nitrous oxide, over mercury, by the heat of a -burning lens. No alteration was produced in the volume of gas, and a -portion of it absorbed by water, left a residuum of one twelfth only. - -Phosphorus was sublimed in pure nitrous oxide over mercury, in a -dark room, by an iron heated _nearly_ to ignition; but no luminous -appearance was perceptible, nor was any gas decomposed. - -_b._ Phosphorus decomposes nitrous oxide at the temperature of -ignition, with greater or less rapidity, according to the degree of -heat. We have already seen, that when phosphorus in active inflammation -is introduced into nitrous oxide, it burns with intensely vivid light. - -Phosphorus was sublimed by a heated wire in a jar filled with nitrous -oxide, standing over warm mercury. In this state of sublimation an iron -heated dull red was introduced to it by being rapidly passed through -the mercury; a light blue flame surrounded the wire, and disappeared as -soon as it ceased to be red. - -To phosphorus sublimed as before, in nitrous oxide, over warm mercury, -a thick wire ignited to whiteness was introduced; a terrible detonation -took place, and the jar was shattered in pieces. - -By employing thick conical jars,[172] containing only a small quantity -of nitrous oxide, I effected the detonation several times with safety; -but on account of the great expansion of the elastic products, the jar -was generally either raised from the mercury, or portions of gas were -thrown out of it. Hence I was unable to ascertain the exact changes -produced by this mode of decomposition. - -[172] Experiments on the detonation of nitrous oxide with phosphorus -in this way require great attention. The detonating jar should be very -conical; the nitrous oxide employed should never equal more than one -eighth of the capacity of the jar. The wire for the inflammation must -be very thick, and curved so as to be easily introduced into the jar. -When ignited, it must be instantaneously passed through the heated -mercury into the jar. - -Perhaps the electric spark might be advantageously applied for -detonating phosphoric vapor with nitrous oxide. - -_c._ As my first attempts to ascertain the constitution of nitrous -oxide were made on its decomposition by phosphorus, I employed many -different modes of partially igniting this substance in it over -mercury, so as to produce a combustion without explosion. - -The first method adopted was inflammation by means of oxygenated -muriate of potash. A small particle of oxygenated muriate of potash was -inserted into the phosphorus to be burnt. On the application of a wire, -moderately hot, to the point of insertion, the salt was decomposed by -the phosphorus, and sufficient fire generated and partially applied -by the slight explosion, to produce the combustion of the phosphorus, -without the previous sublimation of any part of it. - -The second way employed was the ignition of a part of the phosphorus, -by means of the combustion of a small portion of tinder of cotton,[173] -or paper, in contact with it, by the burning glass. - -[173] It will be seen hereafter that these bodies are easily inflamed -in nitrous oxide. - -The third, and most successful mode, was by introducing into the -graduated jar containing the nitrous oxide, the phosphorus in a small -tube containing oxygene, so balanced as to swim on the surface of the -mercury, without communicating with the nitrous oxide. The phosphorus -was fired in the oxygene with an ignited iron wire, by which at the -moment of combustion, the tube containing it was raised into the -nitrous oxide, and thus the inflammation continued. - -_d._ In different experiments, made with accuracy, I found that the -whole of a quantity of nitrous oxide was never decomposable by ignited -phosphorus; the combustion always stopped when the nitrous oxide -remaining was to the nitrogene evolved as about 1 to 5; likewise that -the volume of nitrogene produced was rather less than that of the -nitrous oxide decomposed, and that this deficiency arose from the -formation of nitrous acid by the intense ignition produced during the -process. - -Of one experiment I shall give a detail. - -Temperature being 48°, two cubic inches of pure nitrous oxide, which -had been generated over mercury, were introduced into a jar of the -capacity of 9 cubic inches, graduated to,1 cubic inches, and much -enlarged at the base. A grain of phosphorus was inserted into a small -vessel about one third of an inch long, and half an inch in diameter, -containing about 15 grain measures of very pure oxygene; this vessel, -which swam on the surface of the mercury, was carefully introduced -into the jar containing the nitrous oxide. The phosphorus was fired by -means of a heated wire, and before the oxygene was wholly consumed, the -vessel containing it elevated into the nitrous oxide. The combustion -was extremely vivid and rapid. After the atmospheric temperature was -restored, the gas was rendered opaque by dense white vapor. When this -had been precipitated, and the small vessel removed from the jar, the -gas filled a space nearly equal to 1.9 cubic inches. On introducing to -it a little solution of green muriate of iron, and prussiate of potash, -green prussiate of iron was produced: hence, evidently, nitrous acid -had been formed. - -On the admission of pure water, an absorption of rather more than,3 -took place. - -The 16 measures remaining underwent no perceptible diminution with -nitrous gas; the taper plunged into them was instantly extinguished. - -To ascertain if the phosphoric acid produced in the experiments made -under mercury did not in some measure prevent the decomposition of -the whole of the nitrous oxide by the phosphorus, I introduced into a -mixture of 5 nitrogene and 1 nitrous oxide, ignited phosphorus: but it -was immediately extinguished.[174] - -The Dutch Chemists found that phosphorus might be fused in nitrous -oxide without being luminous. They assert that phosphorus in a state of -inflammation, introduced into this gas, was immediately extinguished; -though when taken out into the atmosphere, it again burnt of its own -accord.[175] It is difficult to account for their mistake. - -[174] Phosphorus burnt feebly with a white flame in a mixture of 4 -nitrogene and 1 nitrous oxide. - -[175] Journal de Physique, xliii. 328. - - -V. _Decomposition of Nitrous Oxide by Phosphorated Hydrogene._ - -_a._ It has been mentioned in Res. II. Div. I. that phosphorated -hydrogene and nitrous oxide posses no action on each other, at -atmospheric temperatures. - -Phosphorated hydrogene mingled with nitrous oxide, is capable of being -inflamed by the electric spark, or by ignition. - -_b. E._ 1. 10 grain measures of phosphorated hydrogene, carefully -produced by means of phosphorus and solution of caustic alkali, were -mingled with 52 measures of nitrous oxide. The electric spark passed -through them, produced a vivid inflammation. The elastic products were -clouded with dense white vapor, and after some minutes filled a space -nearly equal to 60. On the introduction of water, no absorption took -place. When 43 of nitrous gas were admitted, the whole diminished to -70. - -_E._ 2. 25 of nitrous oxide were fired with 10 of phosphorated -hydrogene, by the electric spark. After detonation[176] they filled -a space exactly equal to 25. On the admission of solution of green -sulphate of iron, and prussiate of potash, no blue or green precipitate -was produced. On the introduction of water, no diminution was -perceived. 25 of nitrous gas mingled with them, gave exactly 50. - -[176] In this experiment, as in the last, dense white vapor was -produced. - -_E._ 3. 10 of nitrous oxide, mingled with 20 of phosphorated hydrogene, -could not be inflamed. - -25 of nitrous oxide, with 20 phosphorated hydrogene, inflamed. The -gas after detonation, was rendered opaque by dense white vapor, and -filled a space nearly equal to 45. No absorption took place when -water was introduced. On admitting a little oxygene no white fumes, -or diminution, was perceived. The electric spark passed through the -mixture, produced an explosion, with great diminution. - -_c._ From _E._ 1 it appears, that when a small quantity of -phosphorated hydrogene is inflamed with nitrous oxide, both the -phosphorus and hydrogene are consumed; whilst the superabundant -nitrous oxide, is converted into nitrous acid and atmospheric air, -by the ignition; or a certain quantity is partially decomposed into -atmospheric air by the combination of a portion of its oxygene with the -combustible gas. - -From _E._ 2 we learn, that when the phosphorated hydrogene and nitrous -oxide are to each other as 25 to 10 nearly, they both disappear, whilst -nitrogene is evolved, and water and phosphoric acid produced. Reasoning -concerning the composition of nitrous oxide from this experiment, -we should conclude that it was composed of about 38 oxygene, and 62 -nitrogene. - -The result of _E._ 3 is interesting; we are taught from it that the -affinity of phosphorus for the oxygene of nitrous oxide is stronger -than that of hydrogene, at the temperature of ignition; so that when -phosphorated hydrogene is mingled with a quantity of nitrous oxide, not -containing sufficient oxygene to burn both its constituent parts, the -phosphorus only is consumed, whilst the hydrogene is liberated. - -In repeating the experiments with phosphorated hydrogene that had -remained for some hours in the mercurial apparatus, I did not gain -exactly the same results; for a larger quantity of it was required to -decompose the nitrous oxide, than in the former experiments; doubtless -from its having deposited a portion of its phosphorus. They confirm, -however, the above mentioned conclusions. - -In the course of experimenting, I passed the electric spark, for -a quarter of an hour, through about 60 measures of phosphorated -hydrogene. It underwent no alteration of volume. Phosphorus was -apparently precipitated from it, and it had wholly lost its power of -inflaming, in contact with common air. - - -VI. _Decomposition of Nitrous Oxide by Sulphur._ - -From the phænomena before mentioned,[177] relating to the combustion -of sulphur in nitrous oxide, it was evident that this gas was only -decomposable by it, at a much higher temperature than common air. - -[177] Res. I. Div. III. S. II. - -I introduced into sulphur in contact with nitrous oxide, over mercury -heated to 112°-114°, a wire intensely ignited. It lost much of its heat -in passing through the mercury, but still appeared red in the vessel. -The sulphur rapidly fused, and sublimed without being at all luminous. -This experiment was repeated five or six times, but in no instance -could the combustion of sulphur, by means of the ignited wire, be -effected. - -I inflamed sulphur in nitrous oxide in the same manner as phosphorus; -namely, by introducing it into the small vessel filled with oxygene, -and igniting it by means of the heated wire. In these experiments the -sulphur burnt with a vivid rose-colored light, and much sulphuric, with -a little sulphureous acid, was formed. - -Experimenting in this way I was never, however, able to decompose more -than one third of the quantity of nitrous oxide employed; not only the -nitrogene evolved, but likewise the sulphuric and sulphureous acids -produced, stopping the combustion. - -I found that sulphur in a state of vivid inflammation, when introduced -into a mixture of one fourth nitrogene, and three fourths nitrous -oxide, burnt with a flame very much enlarged, and of a vivid rose -color. In one third nitrogene, and two thirds nitrous oxide, it burnt -feebly with a yellow flame. In equal parts of nitrous oxide and -nitrogene, it was instantly extinguished. - -Sulphur burnt feebly, with a light yellow flame, when introduced -ignited into a mixture of 5 nitrous gas, and 6 nitrous oxide. In one -third nitrous oxide, and two thirds nitrous gas, it was instantly -extinguished. From many circumstances, I am inclined to believe that -sulphur is incapable, at any temperature, of slowly decomposing nitrous -oxide, so as to burn in it with a blue flame, forming sulphureous -acid alone. It appears to attract oxygene from it only when intensely -ignited, so as to form chiefly sulphuric acid, and that with great -rapidity, and vivid inflammation. - - -VII. _Decomposition of Nitrous Oxide by Sulphurated Hydrogene._ - -_a._ Though nitrous oxide and sulphurated hydrogene do not act -upon each other at common temperatures, yet they undergo a mutual -decomposition when mingled together in certain proportions, and ignited -by the electric spark. - -From more than twenty experiments made on the inflammation of -sulphurated hydrogene in nitrous oxide, I select the following as the -most conclusive and accurate. The temperature at which they were made -was from 41° to 49°. - -_b._ _E._ 1. About 35 measures of nitrous oxide were fired with 10 -of sulphurated hydrogene; the expansion during inflammation was very -great, and the flame sky-blue. Immediately after, the gases filled -a space equal to 48 nearly. White fumes were then formed, and they -gradually contracted to 40. On the admission of a little strontian -lime water, a slight absorption took place, with white precipitation; -and the volume occupied by the residual gas nearly equalled 37. On -admitting nitrous gas to these, no perceptible diminution took place. - -_E._ 2. 20 sulphurated hydrogene, with 25 nitrous oxide, could not be -inflamed. - -30 nitrous oxide, with 22 sulphurated hydrogene, could not be inflamed. - -35 nitrous oxide, with 20 sulphurated hydrogene, inflamed with vivid -blue light, and great expansion. After the explosion, the gases filled -exactly the same space as before the experiment; no white fumes were -perceived, and no farther contraction occurred. On the addition of -strontian lime water, a copious precipitation, with diminution, took -place; and the residual gas filled a space nearly equal to 35½. - -_E._ 3. 47 nitrous oxide, and 14 sulphurated hydrogene, inflamed. After -the explosion, the gases filled a space nearly equal to 65; then white -fumes formed, and they gradually diminished to 52. On the introduction -of muriate of strontian, a copious white precipitate was produced; and -on the addition of water, no further absorption took place. To the -residual 52, about 20 of nitrous gas were added; they filled together a -space equal to about 67. - -_c._ In none of the experiments made on the inflammation of sulphurated -hydrogene and nitrous oxide, could I ascertain with certainty the -precipitation of sulphur. In one or two processes the detonating tube -was rendered a little white at the points of contact with the mercury; -but this was most probably owing to the oxydation of the mercury, -either by the heated sulphuric acid formed, or from nitrous acid -produced by the ignition. The presence of nitrous acid I could not -ascertain in these processes by my usual tests, because the combustion -of sulphur over white prussiate of iron, converts it into light green. - -When I introduced an inflamed taper into about 3 parts of sulphurated -hydrogene, and 2 parts of nitrous oxide, in which proportions they -could not have been fired by the electric spark, a blue flame passed -through them, and much sulphur was deposited on the sides of the -vessel. But this sulphur most probably owed its formation to the -decomposition of a portion of sulphurated hydrogene not burnt, by the -sulphureous acid formed from the combustion of the other portion. - -We may then conclude with probability, that sulphurated hydrogene and -nitrous oxide will not decompose each other, when acted on by the -electric spark, unless their proportions are such as to enable the -whole of the sulphurated hydrogene to be decomposed, so that both of -its constituents may become oxygenated, by attracting oxygene from the -nitrous oxide: likewise, that when the sulphurated hydrogene is at its -_maximum_ of inflammation, the hydrogene and sulphur form with the -whole of the oxygene of nitrous oxide, water and sulphureous acid; _E._ -2: whereas at its _minimum_ they produce water, and chiefly, _perhaps_ -wholly, sulphuric acid; at the same time that the nitrous oxide -partially decomposed, is converted into nitrogene, and a gas analogous -to atmospheric air, or into nitrogene, nitrous acid, and atmospheric -air. _E._ 1. _E._ 3. - -By pursuing those experiments, and using larger quantities of gas, -we may probably be able to ascertain from them with accuracy, the -composition of sulphuric and sulphureous acids. - -I own I was disappointed in the results, for I expected to have been -able to ascertain from them, the relative affinities of sulphur, and -hydrogene for the oxygene of nitrous oxide, at the temperature of -ignition. I conjectured that nitrous oxide, mingled with excess of -sulphurated hydrogene, would have been decomposed, and one of the -principles of it evolved unaltered, as was the case with phosphorated -hydrogene. - -If we estimate the composition of nitrous oxide from the quantity of -nitrogene produced in _E._ 2, it is composed of about 61 nitrogene, and -39 oxygene. - - -VIII. _Decomposition of Nitrous Oxide by Charcoal._ - -An account of the analysis of nitrous oxide by charcoal is given in -Res. I. Div. III. I have lately made two experiments on the combustion -of charcoal in nitrous oxide, in which every precaution was taken to -prevent the existence of sources of error. Of one of these I shall give -a detail. - -_E._ Temperature being 51°, about a grain of charcoal, which had been -exposed for some hours to a red heat, was introduced whilst ignited, -under mercury, and transferred into a graduated jar, containing 3 cubic -inches of pure nitrous oxide, standing over dry mercury. - -The focus of a burning lens was thrown on the charcoal; it instantly -inflamed, and burnt with great vividness for near a minute, the gas -being much expanded. The focus was continually applied to it for ten -minutes, when the process appeared at an end. The gases, when the -common temperature and pressure were restored, filled a space equal to -4,2 cubic inches. - -On introducing into them a few grain measures of solution of green -muriate of iron, for the double purpose of saturating them with -moisture, and ascertaining if any nitrous acid had been formed, no -change of volume took place; and prussiate of potash gave with the -muriate a white precipitate only. - -On the admission of a small quantity of concentrated solution of -caustic potash, a diminution of the gas slowly took place; when it was -complete the volume equalled about 3.05 cubic inches. By agitation -in well boiled water, about,9 of these were absorbed; the remainder -appeared to be pure nitrogene. - -The difference between the estimation founded upon the nitrogene -evolved, and that deduced from the carbonic acid generated in this -experiment, is not nearly so great as in that Res. I. Div. III. Taking -about the mean proportions, we should conclude that nitrous oxide was -composed of about 38 oxygene, and 62 nitrogene. - -Charcoal burnt with greater vividness than in common air, in a mixture -of one third nitrogene and two thirds nitrous oxide. In equal parts -of nitrous oxide and nitrogene, its light was barely perceptible. -In one third nitrous oxide, and two thirds nitrogene, it was almost -immediately extinguished. - -As charcoal burns vividly in nitrous gas, when it has been previously -ignited to whiteness, I introduced it into a mixture of equal parts of -nitrous oxide and nitrous gas; it burnt with a deep and bright red. - - -IX. _Decomposition of Nitrous Oxide by Hydrocarbonate._ - -Nitrous oxide, and hydrocarbonate, possess no action on each other, -except at high temperatures. When mingled in certain proportions, and -exposed to the electric shock, a new arrangement of their principles -takes place. - -_E._ 1. Temperature being 53°, 35 of nitrous oxide, mingled with 15 of -hydrocarbonate, were fired by the electric spark; the inflammation was -very vivid, and the light produced, bright red. After the explosion, -the space occupied by the gases equalled about 60. On the admission of -solution of strontian, a copious white precipitate was produced, and -the gas diminished by agitation, to rather more than 35. When 36 of -nitrous gas were added to these, white fumes appeared and the whole -diminished to 62. When a little muriatic acid was poured on the white -precipitate from the solution of strontian, gas was evolved from it, -and it was gradually dissolved. - -_E._ 2. 22 nitrous oxide were inflamed with 20 hydrocarbonate; after -the explosion, they filled a space equal to 45; when strontian -lime water was introduced, white precipitation took place, and the -diminution was to 31. - -To these 31, 14 of nitrous oxide were admitted, and the electric spark -passed through them; an inflammation took place: carbonic acid was -formed, after the absorption of which, the gas remaining filled a space -equal to 43, and did not diminish with nitrous gas. - -The hydrocarbonate employed in these experiments, was procured from -alcohol by means of sulphuric acid. In another set of experiments made -with less accuracy, the same general results were obtained. Whenever -hydrocarbonate inflamed with nitrous oxide, both its constituents were -oxygenated; in all cases carbonic acid was formed, and in no instance -free hydrogene evolved, or charcoal precipitated. - -In the decomposition of nitrous oxide by hydrocarbonate, the residual -nitrogene is less than in other combustions. This circumstance I am -unable to explain. - -Reasoning from analogy, there can be little doubt, but that when -hydrocarbonate is inflamed with excess of nitrous oxide, it will be -only partially decompounded, or converted into nitrogene, nitrous acid, -and atmospheric air. - -The Dutch Chemists have asserted, that charcoal does not burn in -nitrous oxide, except in consequence of the previous decomposition -of the gas by the hydrogene always contained in this substance; and -likewise, that when hydrocarbonate and nitrous oxide were mingled -together, and fired by the electric spark, the hydrogene only was -burnt, whilst the charcoal was precipitated. - -It is difficult to account for these numerous mistakes. Their theory of -the _non-respirability_ of nitrous oxide was founded upon them. They -supposed that the chief use of respiration was to deprive the blood of -its superabundant carbon, by the combination of atmospheric oxygene -with that principle; and that nitrous oxide was highly fatal to life, -because it was incapable of de-carbonating the blood[178]!! - -[178] Journal de Physique, xliii. 334. - -X. _Combustion of Iron in Nitrous Oxide._ - -I introduced into a jar of the capacity of 20 cubic inches, containing -11 cubic inches of nitrous oxide, over mercury, a small quantity of -fine iron wire twisted together, and having affixed to it a particle -of cork. On throwing the focus of a burning glass on the cork, it -instantly inflamed, and the fire was communicated to the wire, which -burnt with great vividness for some moments, projecting brilliant white -sparks. After it had ceased to burn the gas was increased in volume -rather more than three tenths of an inch. The nitrous acid tests were -introduced, but no acid appeared to have been formed. On exposing the -gas to water, near 4,2 cubic inches were absorbed: the 7,1 remaining -appeared to be pure nitrogene. - -From this experiment it is evident that iron at the temperature of -ignition, is capable of decomposing nitrous oxide; likewise that it -is incapable of burning in it when it contains more than three fifths -nitrogene. - -I attempted to inflame zinc in nitrous oxide, in the same way as iron; -but without success. By keeping the focus of a burning glass upon -some zinc filings, in a small quantity of nitrous oxide, I converted -a little of the zinc into white oxide, and consequently decomposed a -portion of the gas. - - -XI. _Combustion of Pyrophorus in Nitrous Oxide._ - -Pyrophorus, which inflames in nitrous gas, and atmospheric air, at or -even below 40°, requires for its combustion in nitrous oxide a much -higher temperature. It will not burn in it, or alter it, even at 212°. - -I have often inflamed pyrophorus in nitrous oxide over mercury, by -means of a wire strongly heated, but not ignited. The light produced -by the ignition of pyrophorus in nitrous oxide is white, like that -produced by it in oxygene: in nitrous gas it is red. - -When pyrophorus burns out in nitrous oxide, a little increase of the -volume of gas is produced. Strontian lime water agitated in this gas -becomes clouded; but the quantity of carbonic acid formed is extremely -minute. I have never made any delicate experiments on the combustion of -pyrophorus in nitrous oxide. - - -XII. _Combustion of the Taper in Nitrous Oxide._ - -It has been noticed by different experimentalists, that the taper burns -with a flame considerably enlarged in nitrous oxide: sometimes with a -vivid light and crackling noise, as in oxygene; at other times with a -white central flame, surrounded by a feeble blue one. - -My experiments on the combustion of the taper in nitrous oxide, were -chiefly made with a view to ascertain the cause of the double flame. - -When the inflamed taper is introduced into pure nitrous oxide, it burns -at first with a brilliant white light, and sparkles as in oxygene. As -the combustion goes on, the brilliancy of the flame diminishes; it -gradually lengthens, and becomes surrounded with a pale blue cone of -light, from the apex of which much unburnt charcoal is thrown off, -in the form of smoke. The flame continues double to the end of the -process. - -When the residual gases are examined after combustion, much nitrous -acid is found suspended in them; and they are composed of carbonic -acid, nitrogene, and about one fourth of undecompounded nitrous oxide. - -The double flame depends upon the nitrous acid formed by the ignition; -for it can be produced by plunging the taper into common air containing -nitrous acid vapor, or into a mixture of nitrous oxide and nitrogene, -through which nitrous acid has been diffused. It is never perceived in -the combustion of the taper, till much nitrous acid is formed. - -In attempting to respire some residual gas of nitrous oxide, in which -a taper had burnt out, I found it so highly impregnated with nitrous -acid, as to disable me from even taking it into my mouth. - -The taper burns in a mixture of equal parts nitrous oxide and -nitrogene, at first with a flame nearly the same as that of a candle in -common air; white. Before its extinction the interior white flame, and -exterior blue flame, are perceived. - -The taper is instantly extinguished in a mixture of one fourth nitrous -oxide, and three fourths nitrogene. - -In a mixture of equal parts nitrous oxide and nitrous gas, the taper -burns at first with nearly as much brilliancy as in pure nitrous oxide; -gradually the double and feeble flame is produced. - - -XIII. _On the Combustion of different Compound Bodies in Nitrous Oxide._ - -All the solid and fluid compound inflammable bodies on which I have -experimented, burn in nitrous oxide, at high temperatures. Wood, -cotton, and paper, are easily inflamed in it by the burning glass. -During their combustion, nitrous acid is always formed, carbonic acid, -and water produced, and nitrogene evolved, rather less in bulk than the -nitrous oxide decomposed. - -I have already mentioned that alcohol and ether are soluble in nitrous -oxide. When an ignited body is introduced into the solution of -alcohol, or ether in nitrous oxide, a slight explosion takes place. - - -XIV. _General Conclusions relating to the Decomposition of Nitrous -Oxide, and to its Analysis._ - -From what has been said in the preceding sections, it appears that -the inflammable bodies, in general, require for their combustion in -nitrous oxide, much higher temperatures than those at which they burn -in atmospheric air, or oxygene. - -When intensely heated they decompose it, with the production of much -heat and light, and become oxygenated. - -During the combustion of solid or fluid bodies, producing flame, in -nitrous oxide, nitrous acid is generated, most probably from a new -arrangement of principles, analogous to those observed in Sect. II, by -the ignition of that part of the gas not in contact with the burning -substance. Likewise when nitrous oxide in excess is decomcomposed by -inflammable gases, nitrous acid, and sometimes a gas analogous to -common air, is produced, doubtless from the same cause. - -Pyrophorus is the only body that inflames in nitrous oxide, below the -temperature of ignition. - -Phosphorus burns in it with the blue flame, probably forming with its -oxygene only phosphoreous acid at the dull red heat, and with the -intensely vivid flame, producing phosphoric acid at the white heat. - -Hydrogene, charcoal, sulphur, iron, and the compound inflammable -bodies, decompose it only at heats equal to, or above, that of -ignition: _probably_ each a different temperature. - -From the phænomena in Sect. V. it appears, that at the temperature of -intense ignition, phosphorus has a stronger affinity for the oxygene -of nitrous oxide than hydrogene; and reasoning from the different -degrees of combustibility of the inflammable bodies, in mixtures of -nitrous oxide and nitrogene, and from other phænomena, we may conclude -with probability, that at about the white heat, the affinity of the -combustible bodies for oxygene takes place in the following order. -Phosphorus, hydrogene, charcoal,[179] iron, sulphur, &c. - -This order of attraction is very different from that obtaining at the -red heat; in which temperature charcoal and iron have a much stronger -affinity for oxygene than either phosphorus or hydrogene.[180] - -[179] As is proved by the decomposition of oxide of iron and sulphuric -acid by charcoal, at that temperature. - -[180] Hydrogene at or about the red heat, appears to attract oxygene -stronger than phosphorus. See Dr. Priestley’s experiments, vol. i. page -262. - -The smallest quantity of oxygene given in the different analyses of -nitrous oxide just detailed, is thirty five hundred parts; the greatest -proportion is thirty-nine. - -Taking the mean estimations from the most accurate experiments, we may -conclude that 100 grains of the known ponderable matter of nitrous -oxide, consist of about 36,7 oxygene, and 63,3 nitrogene; or taking -away decimals, of 37 oxygene to 63 nitrogene; which is identical with -the estimation given in Research I. - - -XV. _Observations on the combinations of Oxygene and Nitrogene._ - -During the decompositions of the combinations of oxygene and nitrogene -by combustible bodies, a considerable momentary expansion of the acting -substances, and the bodies in contact with them is generally produced, -connected with increased temperature; whilst light is often generated -to a great extent. - -Of the causes of these phænomena we are at present ignorant. Our -knowledge of them must depend upon the discovery of the precise nature -of heat and light, and of the laws by which they are governed. The -application of general hypotheses to isolated facts can be of little -utility; for this reason I shall at present forbear to enter into any -discussions concerning those agents, which are imperceptible to the -senses, and known only by solitary effects. - -Analysis and synthesis clearly prove that oxygene and nitrogene -constitute the known ponderable matter of atmospheric air, nitrous -oxide, nitrous gas, and nitric acid. - -That the oxygene and nitrogene of atmospheric air exist in chemical -union, appears almost demonstrable from the following evidences. - -1st. The equable diffusion of oxygene and nitrogene through every part -of the atmosphere, which can hardly be supposed to depend on any other -cause than an affinity between these principles.[181] - -[181] That attraction must be called chemical, which enables bodies of -different specific gravities to unite in such a manner as to produce a -compound, in every part of which the constituents are found in the same -proportions to each other. Atmospheric air, examined after having been -at perfect rest in closed vessels, for a great length of time, contains -in every part the same proportions of oxygene and nitrogene; whereas -if no affinity existed between these principles, following the laws -of specific gravity, they ought to separate; the oxygene forming the -inferior, the nitrogene the superior stratum. - -The supposition of the _chemical_ composition of atmospheric air, has -been advanced by many philosophers. The two first evidences have been -often noticed. - -2dly. The difference between the specific gravity of atmospheric -air, and a mixture of 27 parts oxygene and 73 nitrogene, as found by -calculation; a difference apparently owing to expansion in consequence -of combination. - -3dly. The conversion of nitrous oxide into nitrous acid, and a gas -analogous to common air, by ignition. - -4thly. The solubility of atmospheric air undecompounded in water. - -ATMOSPHERIC AIR, then, may be considered as the least intimate of the -combinations of nitrogene and oxygene. - -It is an elastic fluid, permanent at all known temperatures, consisting -of,73 nitrogene, and,27 oxygene. It is decomposable at certain -temperatures, by most of the bodies possessing affinity for oxygene. It -is soluble in about thirty times its bulk of water, and as far as we -are acquainted with its affinities, incapable of combining with most of -the simple and compound substances. 100 cubic inches of it weigh about -31 grains at 55° temperature, and 30 atmospheric pressure. - -NITROUS OXIDE is a gas unalterable in its constitution, at temperatures -below ignition. It is composed of oxygene and nitrogene, existing -_perhaps_ in the most intimate union which those substances are capable -of assuming.[182] Its properties approach to those of acids. It is -decomposable by the combustible bodies at very high temperatures, is -soluble in double its volume of water, and in half its bulk of most of -the inflammable fluids. It is combinable with the alkalies, and capable -of forming with them peculiar salts. 100 grains of it are composed of -about 63 nitrogene, and 37 oxygene. 100 cubic inches of it weigh 50 -grains, at 55° temperature, and 30 atmospheric pressure. - -[182] For it is unalterable by those bodies which are capable of -attracting oxygene from nitrous gas and nitrous acid, at common -temperatures. - -NITROUS GAS is composed of about,56 oxygene, and,44 nitrogene, in -intimate union. It is soluble in twelve times its bulk of water, and -is combinable with the acids, and certain metallic solutions; it -is possessed of no acid properties, and is decomposable by most of -the bodies that attract oxygene strongly, at high temperatures. 100 -cubic inches of it weigh about 34 grains, at the mean temperature and -pressure. - -NITRIC ACID is a substance permanently aëriform at common temperatures, -composed of about 1 nitrogene, to 2,3 oxygene. It is soluble to a -great extent in water, and combinable with the alkalies, and nitrous -gas. It is decomposable by most of the combustible bodies, at certain -temperatures. 100 cubic inches of it weigh, at the mean temperature and -pressure, nearly 76 grains. - - - - -RESEARCH III. - -RELATING TO THE RESPIRATION OF NITROUS OXIDE, AND OTHER GASES. - - -DIVISION I. - - _EXPERIMENTS and OBSERVATIONS on the EFFECTS produced - upon ANIMALS by the RESPIRATION of NITROUS OXIDE._ - - -I. _Preliminaries._ - -The term _respirable_, in its physiological application, has been -differently employed. Some times by the respirability of a gas has been -meant, its power of supporting life for a great length of time, when -repeatedly applied to the blood in the lungs. At other times all gases -have been considered as respirable, which were capable of introduction -into the lungs by voluntary efforts, without any relation to their -vitality. - -In the last sense the word respirable is most properly employed. In -this sense it is used in the following sections. - -Non-respirable gases are those, which when applied to the external -organs of respiration, stimulate the muscles of the epiglottis in inch -a way as to keep it perfectly close on the glottis; thus preventing -the smallest particle of gas from entering into the bronchia, in spite -of voluntary exertions; such are carbonic acid, and acid gases in -general.[183] - -[183] See the curious experiments of Rosier, Journal de Physique, 1786, -vol. 1, pag. 419. - -Of respirable gases, or those which are capable of being taken into the -lungs by voluntary efforts. - -One only has the power of uniformly supporting life;—atmospheric air. -Other gases, when respired, sooner or later produce death; but in -different modes. - -Some, as nitrogene and hydrogene, effect no positive change in the -venous blood. Animals immersed in these gases die of a disease produced -by privation of atmospheric air, analogous to that occasioned by their -submersion in water, or non-respirable gases. - -Others, as the different varieties of hydrocarbonate, destroy life -by producing some positive change[184] in the blood, which probably -immediately renders it incapable of supplying the nervous and muscular -fibres with principles essential to sensibility and irritability. - -Oxygene, which is capable of being respired for a much greater length -of time than any other gas, except common air, finally destroys life; -first producing changes in the blood, connected with new living -action.[185] - -[184] As appears from the experiments of Dr. Beddoes; likewise those of -Mr. Watt. - -[185] As appears from the experiments of Lavoisier and Dr. Beddoes; and -as will be seen hereafter. - -After experiments, to be detailed hereafter, made upon myself and -others, had proved that nitrous oxide was respirable, and capable -of supporting life for a longer time than any of the gases, except -atmospheric air and oxygene, I was anxious to ascertain the effects of -it upon animals, in cases where its action could be carried to a full -extent; and to compare the changes occasioned by it in their organs, -with those produced by other powers. - - -II. _On the respiration of Nitrous Oxide by warm-blooded Animals._ - -The nitrous oxide employed in the following experiments, was procured -from nitrate of ammoniac, and received in large jars, filled with water -previously saturated with the gas. The animal was introduced into the -jar, by being carried under the water; after its introduction, the jar -was made to rest on a shelf, about half an inch below the surface of -the water; and the animal carefully supported, so as to prevent his -mouth from resting in the water. - -This mode of experimenting, either under water or mercury, is -absolutely necessary, to ascertain with accuracy the effects of -pure gases on living beings. In some experiments that I made on the -respiration of nitrous oxide, by animals that were plunged into jars -of it opened in the atmosphere, and immediately closed after their -introduction, the unknown quantities of common air carried in, were -always sufficient to render the results perfectly inaccurate. - -Animals suffer little or nothing by being passed through water. - -That the phænomena in these experiments might be more accurately -observed, two or three persons were always present at the time of their -execution, and an account of them was noted down immediately after. - -_a._ A stout and healthy young cat, of four or five months old, was -introduced into a large jar of nitrous oxide. For ten or twelve moments -he remained perfectly quiet, and then began to make violent motions, -throwing himself round the jar in every direction. In two minutes -he appeared quite exhausted, and sunk quietly to the bottom of the -jar. On applying my hand to the thorax, I found that the heart beat -with extreme violence; on feeling about the neck, I could distinctly -perceive a strong and quick pulsation of the carotids. In about three -minutes the animal revived, and panted very much; but still continued -to lie on his side. His inspirations then became longer and deeper, and -he sometimes uttered very feeble cries. In four minutes the pulsations -of the heart appeared quicker and feebler. His inspirations were at -long intervals, and very irregular; in five minutes the pulse was -hardly perceptible; he made no motions, and appeared wholly senseless. -After five minutes and quarter he was taken out, and exposed to the -atmosphere before a warm fire. In a few seconds he began to move, and -to take deep inspirations. In five minutes he attempted to rise on his -legs; but soon fell again, the extremities being slightly convulsed. -In eight or nine minutes he was able to walk, but his motions were -staggering and unequal, the right leg being convulsed, whilst the -other was apparently stiff and immoveable; in about half an hour he -was almost completely recovered. - -_b._ A healthy kitten, of about six weeks old, was introduced into -nitrous oxide. She very soon began to make violent exertions, and -in less than a minute fell to the bottom of the receiver, as if -apoplectic. At this moment, applying my hand to her side, I felt the -heart beating with great violence. She continued gasping, with long -inspirations, for three minutes and half; at the end of five minutes -and half she was taken out completely dead. - -_c._ Another kitten of the same breed was introduced into nitrous -oxide, the day after. She exhibited the same phænomena, and died in it -in about five minutes and half. - -_d._ A small dog that had accidentally met with a dislocation of the -vertebræ of the loins, and was in great pain, as manifested by his -moaning and whining, was introduced into a large jar of nitrous oxide. -He immediately became quiet, and lay on his side in the jar, breathing -very deeply. In four minutes his respiration became noisy, and his -eyes sparkled very much. I was not able to apply my hand to the -thorax. In five minutes he appeared senseless, and in seven minutes was -perfectly dead. - -_e._ A strong rabbit, of ten or twelve months old, was introduced into -nitrous oxide. He immediately began to struggle very much, and in a -minute fell down senseless: in two minutes the legs became convulsed, -and his inspirations were deep and noisy: in less than five minutes he -appeared perfectly dead. - -_f._ A rabbit of a month old introduced into nitrous oxide, became -senseless in less than a minute; the pulsations of the heart were very -strong at this moment: they gradually became weaker, and in three -minutes and half the animal was dead. - -_g._ Another rabbit of the same breed, after being rendered senseless -in nitrous oxide in a minute and half, was taken out. He soon became -convulsed; in a minute began to breathe quickly; in two minutes -attempted to rise, but staggered, and fell again on his side. His -hinder legs were paralytic for near five minutes. In twenty he had -almost recovered. - -_h._ A middle sized guinea-pig was much convulsed, after being in -nitrous oxide for a minute. In two minutes and half he was senseless. -Taken out at this period, he remained for some minutes by the side of -a warm fire, without moving; his fore legs then became convulsed; his -hind legs were perfectly paralytic. In this state he continued, without -attempting to rise or move, for near an hour, when he died. - -_i._ A large and old guinea-pig died in nitrous oxide, exhibiting the -same phænomena as the other animals, in about five minutes and quarter. -A young one was killed in three minutes and half. - -_j._ A small guinea-pig, after breathing nitrous oxide for a minute and -half, was taken out, and placed before a warm fire. He was for a few -minutes a little convulsed; but in a quarter of an hour got quite well, -and did not relapse. - -_k._ A large mouse introduced into nitrous oxide, was for a few -seconds very active. In half a minute he fell down senseless; in a -minute and quarter he appeared perfectly dead. - -_l._ A mouse taken out of nitrous oxide, after being in it for half a -minute, continued convulsed for some minutes, but finally recovered. - -_m._ A young hen was introduced into a vessel filled with nitrous -oxide. She immediately began to struggle very much; fell on her breast -in less than half a minute, and in two minutes was quite dead. - -_n._ A goldfinch died in nitrous oxide in less than a minute. - -In each of these experiments a certain absorption of the gas was always -perceived, the water rising in the jar during the respiration of the -animal. From them we learn - -1st. That nitrous oxide is destructive when respired for a certain time -to the warm-blooded animals, apparently previously exciting them to a -great extent. - -2dly. That when its operation is stopped before compleat exhaustion is -brought on, the healthy living action is capable of being gradually -reproduced, by enabling the animal to respire atmospheric air. - -3dly. That exhaustion and death is produced in the small animals by -nitrous oxide sooner than in the larger ones, and in young animals of -the same species, in a shorter time than in old ones, as indeed Dr. -Beddoes had conjectured a priori would be the case. - -Most of the animals destroyed in these experiments were examined after -death; the appearances in their organs were peculiar. To prevent -unnecessary repetitions, an account of them will be given in the fourth -section. - - -III. _Effects of the respiration of Nitrous Oxide upon animals, as -compared with those produced by their immersion in Hydrogene and Water._ - -Before the following experiments were made, a number of circumstances -had convinced me that nitrous oxide acted on animals by producing some -positive change in their blood, connected with new living action of the -irritable and sensitive organs, and terminating in their death. - -To ascertain however, the difference between the effects of this gas -and those of hydrogene and non-respirable gases, I proceeded in the -following way. - -_a._ Of two healthy rabbits of about two months old, of the same breed, -and nearly of the same size. - -One was introduced into nitrous oxide. In a half a minute, it had -fallen down apparently senseless. On applying my hand to the thorax, -the action of the heart appeared at first, very quick and strong, it -gradually became weaker, and in two minutes and half, the animal was -taken out quite dead. - -The other was introduced into a jar of pure hydrogene through water. -He immediately began to struggle very much, and in a quarter of a -minute fell on his side. On feeling the thorax, the pulsations of the -heart appeared very quick and feeble, they gradually diminished; his -breathing became momentarily shorter, and in rather more than three -quarters of a minute, he was taken out dead. Dr. Kinglake was present -at this experiment, and afterwards dissected both of the animals. - -_b._ Of two similar rabbits of the same breed, nearly three months -old. One was introduced into nitrous oxide, and after being rendered -senseless by the respiration of it for nearly a minute and half, was -exposed to the atmosphere, before a warm fire. He recovered gradually, -but was occasionally convulsed, and had a paralysis of one of his -hinder legs for some minutes: in an hour he was able to walk. The -other, after being immerged in hydrogene for near half a minute, was -restored to the atmosphere apparently inanimate. In less than a minute -he began to breathe, and to utter a feeble noise; in two minutes -was able to walk, and in less than three minutes appeared perfectly -recovered. - -_c._ A kitten of about two months old, was introduced into a jar of -nitrous oxide, at the same time that another of the same breed was -plunged under a jar of water. They both struggled very much. The -animal in the nitrous oxide fell senseless before that under water had -ceased to struggle, and to throw out air from its lungs. In two minutes -and three quarters, the animal under water was quite dead: it was taken -out and exposed to heat and air, but did not shew the slightest signs -of life. At the end of three minutes and half, the animal in nitrous -oxide began to gasp, breathing very slowly; at four minutes and three -quarters it was yet alive; at the end of five minutes and quarter it -appeared perfectly dead. It was taken out, and did not recover. - -From these experiments it was evident, that animals lived at least -twice as long in nitrous oxide as in hydrogene or water. Consequently -from this circumstance alone, there was every reason to suppose that -their death in nitrous oxide could not depend on the simple privation -of atmospheric air; but that it was owing to some peculiar changes -effected in the blood by the gas. - - -IV. _Of the changes effected in the Organisation of warm-blooded -Animals, by the respiration of Nitrous Oxide._ - -The external appearance of animals that have been destroyed in nitrous -oxide, is very little different from that of those killed by privation -of atmospheric air. The fauces and tongue appear of a dark red, and the -eyes are dull, and a little protruded. Their internal organs, however, -exhibit a very peculiar change. The lungs are pale brown red, and -covered here and there with purple spots; the liver is of a very bright -red, and the muscular fibre in general dark. Both the auricles and -ventricles of the heart are filled with blood. The auricles contract -for minutes after the death of the animal. The blood in the left -ventricle, and the aorta, is of a tinge between purple and red, whilst -that in the right ventricle is of a dark color, rather more purple -than the venous blood. But these appearances, and their causes, will -be better understood after the following comparative observations are -read. - -_a._ Of two similar rabbits, about eight months old, one A, was killed -by exposure for near six minutes to nitrous oxide, the other, B, was -destroyed by a blow on the head. - -They were both opened as speedily as possible. The lungs of B were -pale, and uniform in their appearance; this organ in A was redder, and -every where marked with purple spots. The liver of A was of a dark and -bright red, that of B of a pale red brown. The diaphragm of B, when -cut, was strongly irritable; that of A rather darker, and scarce at all -contractile. All the cavities of the heart contracted for more than 50 -minutes in B. The auricles contracted for near 25 minutes with force -and velocity in A: but the ventricles were almost inactive. The vena -cava, and the right auricle, in A, were filled with blood, apparently a -shade darker than in B. The blood in the left auricle, and the aorta, -appeared in A of a purple, a shade brighter than that of the venous -blood. In the left auricle of B it was red. - -I opened the head of each, but not without injuring the brains, so -that I was unable to make any accurate comparison. The color of the -brain in A appeared rather darker than in B. - -_b._ Two rabbits, C and D, were destroyed, C by immersion in nitrous -oxide, D in hydrogene: they were both dissected by Dr. Kinglake. -The blood in the pulmonary vein and the left auricle of C was of a -different tinge, from that in D more inclined to purple red. The -membrane of the lungs in C was covered with purple spots, that of D was -pale and uniform in its appearance. The brain in C was rather darker -than in D; but there was no perceptible effusion of blood into the -ventricles either in D or C. The liver in C was of a brighter red than -in health, that in D rather paler. - -_c._ In the last experiment, the comparative irritability of the -ventricles and auricles of the heart and the muscular fibre in the two -animals, had not been examined. That these circumstances might be -noticed, two rabbits, E and F were killed; E under water in about a -minute, and F in nitrous oxide in three minutes. They were immediately -opened, and after a minute, the appearance of the heart, and organs of -respiration observed. - -Both the right and left ventricles of the heart in F contracted but -very feebly; the auricles regularly and quickly contracted; the aorta -appeared perfectly full of blood. In E, a feeble contraction of the -left sinus venosus and auricle was observed; the left ventricle did not -contract: the right contracted, but more slowly than in F. In a few -minutes, the contractions of the ventricles in F had ceased, whilst -the auricles contracted as strongly and quickly as before. The blood -in the pulmonary veins of F was rather of a redder purple than in E; -the difference of the blood in the vena cava was hardly perceptible, -perhaps it was a little more purple in F. The membranous substance of -the lungs in F was spotted with purple as from extravasated blood, -whilst that in E was pale. The brain in F was darker than in E. On -opening the ventricles no extravasation of blood was perceptible. The -auricles of the heart in F contracted strongly for near twenty minutes, -and then gradually their motion became less frequent; in twenty-eight -minutes it had wholly ceased. The right auricle and ventricle in E, -occasionally contracted for half an hour. The livers of both animals -were similar when they were first opened, of a dark red; that of F -preserved its color for some time when exposed to the atmosphere; -whilst that of E almost immediately became paler under the same -circumstances. - -The peristaltic motion continued for nearly an equal time in both -animals. - -_d._ The sternum of a young rabbit was removed so that the heart and -lungs could be perceived, and he was introduced into a vessel filled -with nitrous oxide; the blood in the pulmonary veins gradually became -more purple, and the heart appeared to beat quicker than before, all -the muscles contracting with great force. After he had been in about -a minute, spots began to appear on the lungs, though the contractions -of the heart became quicker and weaker; in three minutes and half he -was quite dead; after death the ventricles contracted very feebly, -though the contractions of the auricles were as strong almost after the -end of five minutes as at first. This animal was passed through water -saturated with nitrous oxide; possibly this fluid had some effect on -his organs. - -Besides these animals, many others, as guinea-pigs, mice and birds, -were dissected after being destroyed in nitrous oxide; in all of them -the same general appearance was observed. Their muscular fibre almost -always appeared less irritable than that of animals destroyed, by -organic læsion of part of the nervous system, in the atmosphere. The -ventricles of the heart in general, contracted feebly and for a very -short time; whilst the auricles continued to act for a great length of -time. The lungs were dark in their appearance, and always suffused here -and there with purple; the blood in the pulmonary veins when slightly -observed, appeared dark, like venous blood, but when minutely examined, -was evidently much more purple. The blood in the vena cava, was darker -than that in the pulmonary veins. The cerebrum was dark. - -In a late experiment, I thought I perceived a slight extravasation of -blood in one of the ventricles of the brain in a rabbit destroyed in -nitrous oxide; but as this appearance had not occurred in the animals -I had examined before, or in those dissected by Dr. Kinglake, and Mr. -King, Surgeon, I am inclined to refer it to an accidental cause. At my -request, Mr. Smith, Surgeon, examined the brain of a young rabbit that -had been killed in his presence in nitrous oxide; he was of opinion -that no effusion of blood into the ventricles had taken place. - -In comparing the external appearance of the crural nerves in two -rabbits that had been dissected by Dr. Kinglake, having been destroyed -one in hydrogene, the other in nitrous oxide, we could perceive no -perceptible difference. - -It deserves to be noticed, that whenever the gall bladder and the -urinary bladder have been examined in animals destroyed in nitrous -oxide, they have been always distended with fluid; which is hardly ever -the case in animals killed by privation of atmospheric air. - -In the infancy of my experiments on the action of nitrous oxide upon -animals, I thought that it rendered the venous blood less coagulable; -but this I now find to be a mistake. The blood from the pulmonary -veins of animals killed in nitrous oxide, does not sensibly differ in -this respect from the arterial blood of those destroyed in hydrogene, -and both become vermilion nearly in the same time when exposed to the -atmosphere. - -In describing the various shades of color of the blood in the preceding -observations on the different dissected animals, the poverty of -the language of color, has obliged me to adopt terms, which I fear -will hardly convey to the mind of the reader, distinct notions of -the differences observable by minute examination in the venous and -arterial blood of animals that die of privation of atmospheric air, -and of those destroyed by the action of nitrous oxide. This difference -can only be observed in the vessels by means of a strong light; it -may however be easily noticed in the fluid blood by the introduction -of it from the arteries or veins at the moment of their incision, -between two polished surfaces of white glass,[186] so closely adapted -to each other, as to prevent the blood from coming in contact with the -atmosphere. - -[186] The colour of common venous blood, examined in this way, -resembles that of the paint called by colour-men red ochre; that of -blood saturated with nitrous oxide, approaches to the tinge of lake. - -Having four or five times had an opportunity of bleeding people in -the arm for trifling complaints, I have always received the blood in -phials, filled with various gases, in a mode to be described hereafter. -Venous blood agitated in nitrous oxide, compared with similar blood -in common air, hydrogene, and nitrogene, was always darker and more -purple than the first, and much brighter and more florid than the -two last, which were not different in their color from venous blood, -received between two surfaces of glass. It will be seen hereafter, that -the coagulum of venous blood is rendered more purple when exposed to -nitrous oxide, whilst the gas is absorbed; likewise that blood altered -by nitrous oxide, is capable of being again rendered vermilion, by -exposure to the air. - -The appearances noticed in the above mentioned experiments, in the -lungs of animals destroyed in nitrous oxide, are similar to those -observed by Dr. Beddoes, in animals that had been made to breathe -oxygene for a great length of time. - -There were many reasons for supposing that the large purple spots -in the lungs of animals destroyed in nitrous oxide, were owing to -extravasation of venous blood from the capillary vessels; their coats -being broken by the highly increased arterial action. To ascertain -whether these phænomena existed at a period of the action of nitrous -oxide, when the animal was recoverable by exposure to the atmosphere. - -I introduced a rabbit of six months old, into a vessel of nitrous -oxide, and after a minute, when it had fallen down apparently -apoplectic, plunged him wholly under water; he immediately began to -struggle, and what surprised me very much, died in less than a minute -after submersion. On opening the thorax, the blood in the pulmonary -veins was nearly of the color of that in animals that have been simply -drowned. The lungs were here and there, marked with a few points; -but there were no large purple spots, as in animals that have been -wholly destroyed in nitrous oxide: the right side of the heart only -contracted. In this experiment, the excitement from the action of the -gas was probably carried to such an extent, as to produce indirect -debility. There are reasons for supposing, that animals after having -been excited to but a small extent by the respiration of nitrous oxide, -will live under water for a greater length of time, than animals -previously made to breathe common air. - - -V. _Of the respiration of mixtures of Nitrous Oxide, and other gases, -by warm-blooded Animals._ - -_a._ A rabbit of near two months old, was introduced into a mixture of -equal parts hydrogene and nitrous oxide through water. He immediately -began to struggle; in a minute fell on his side; in three minutes -gasped, and made long inspirations; and in four minutes and half, was -dead. On dissection, he exhibited the same appearances as animals -destroyed in nitrous oxide. - -_b._ A large and strong mouse was introduced into a mixture of three -parts hydrogene to one part nitrous oxide. He immediately began to -struggle very much, in half a minute, became convulsed, and in about a -minute, was quite dead. - -_c._ Into a mixture of one oxygene, and three nitrous oxide, a small -guinea-pig was introduced. He immediately began to struggle, and in two -minutes reposed on his side, breathing very deeply. He made afterwards -no violent muscular motion; but lived quietly for near fourteen -minutes: at the end of which time, his legs were much convulsed. He was -taken out, and recovered. - -_d._ A mouse lived apparently without suffering, for near ten minutes, -in a mixture of 1 atmospheric air, and 3 nitrous oxide, at the end of -eleven minutes he began to struggle, and in thirteen minutes became -much convulsed. - -_e._ A cat of three months old, lived for seventeen minutes, in a -very large quantity of a mixture of 1 atmospheric air, and 12 nitrous -oxide. On her first introduction she was very much agitated and -convulsed, in a minute and half she fell down as if apoplectic, and -continued breathing very deeply during the remainder of the time, -sometimes uttering very feeble cries. When taken out, she appeared -almost inanimate, but on being laid before the fire, gradually began to -breathe and move; being for some time, like most of the animals that -have recovered after breathing nitrous oxide, convulsed on one side, -and paralytic the other. - -_f._ A goldfinch lived for near five minutes in a mixture of equal -parts nitrous oxide and oxygene, without apparently suffering. Taken -out, he appeared faint and languid, but finally recovered.[187] - -[187] Small birds suffer much from cold when introduced into gases -through water. In this experiment, the goldfinch was immediately -inserted into a large mouthed phial, filled with the gases, and opened -in the atmosphere. - - -VI. _Recapitulation of facts relating to the respiration of Nitrous -Oxide, by warm-blooded Animals._ - -1. Warm-blooded animals die in nitrous oxide infinitely sooner than in -common air or oxygene; but not nearly in so short a time as in gases -incapable of effecting positive changes in the venous blood, or in -non-respirable gases. - -2. The larger animals live longer in nitrous oxide than the smaller -ones, and young animals die in it sooner than old ones of the same -species. - -3. When animals, after breathing nitrous oxide, are removed from it -before compleat exhaustion has taken place, they are capable of being -restored to health under the action of atmospheric air. - -4. Peculiar changes are effected in the organs of animals by the -respiration of nitrous oxide. In animals destroyed by it, the arterial -blood is purple red, the lungs are covered with purple spots, both the -hollow and compact muscles are _apparently_ very inirritable, and the -brain is dark colored. - -5. Animals are destroyed by the respiration of mixtures of nitrous -oxide and hydrogene nearly in the same time as by pure nitrous oxide; -they are capable of living for a great length of time in nitrous oxide -mingled with very minute quantities of oxygene or common air. - -These facts will be reasoned upon in the next division. - - -VII. _Of the respiration of Nitrous Oxide by amphibious Animals._ - -As from the foregoing experiments, it appeared that the nitrous oxide -destroyed warm-blooded animals by increasing the living action of their -organs to such an extent, as finally to exhaust their irritability and -sensibility; it was reasonable to conjecture that the cold-blooded -animals, possessed of voluntary power over respiration, would so -regulate the quantity of nitrous oxide applied to the blood in their -lungs as to bear its action for a great length of time. This conjecture -was put to the test of experiment; the following facts will prove its -error. - -_a._ Of two middle sized water-lizards, one was introduced into a small -jar filled with nitrous oxide, over moist mercury, by being passed -through the mercury; the other was made to breathe hydrogene, by being -carried into it in the same manner. - -The lizard in nitrous oxide, in two or three minutes, began to make -violent motions, appeared very uneasy, and rolled about the jar in -every direction, sometimes attempting to climb to the top of it. The -animal in hydrogene was all this time very quiet, and crawled about the -vessel without being apparently much affected. At the end of twelve -minutes, the lizard in nitrous oxide was lying on his back seemingly -dead; but on agitating the jar he moved a little; at the end of fifteen -minutes he did not move on agitation, and his paws were resting on his -belly. He was now taken out stiff and apparently lifeless, but after -being exposed to the atmosphere for three or four minutes, took an -inspiration, and moved his head a little; he then raised the end of his -tail, though the middle of it was still stiff and did not bend when -touched. His four legs remained close to his side, and were apparently -useless; but on pricking them with the point of a lancet, they became -convulsed. After being introduced into shallow water, he was able to -crawl in a quarter of an hour, though his motions were very irregular. -In an hour he was quite well. The animal in hydrogene appeared to have -suffered very little in three quarters of an hour, and had raised -himself against the side of the jar. At the end of an hour he was taken -out, and very soon recovered. - -_b._ Some hours after, the same lizards were again experimented upon. -That which had been inserted into hydrogene in the last experiment, -being now inserted into nitrous oxide. - -This lizard was apparently lifeless in fourteen minutes, having tumbled -and writhed himself very much during the first ten minutes. Taken out -after being in twenty-five minutes, he did not recover. The other -lizard lived in hydrogene for near an hour and quarter, taken out after -an hour and twenty minutes, he was dead. - -These animals were both opened, but the viscera of the nitrous oxide -lizard were so much injured by the knife, that no accurate comparison -of them with those of the other could be made, I thought that the lungs -appeared rather redder. - -_c._ Of two similar large water-lizards, one was introduced into a -vessel standing over mercury, wholly filled with water that had been -long boiled and suffered to cool under mercury. - -The animal very often rose to the top of the jar as, if in search -of air, during the first half hour; but shewed no other signs of -uneasiness. At the end of three quarters of an hour, he became very -weak, and appeared scarcely able to swim in the water. Taken out at the -end of fifty minutes, he recovered. - -The other was inserted into nitrous oxide. After much struggling, -he became senseless in about fifteen minutes, and lay on his back. -Taken out at the end of twenty minutes, he remained for a long time -motionless and stiff, but in a quarter of an hour, began to move some -of his limbs. - -From these experiments, we may conclude, that water-lizards, and most -probably the other amphibious animals, die in nitrous oxide in a much -shorter time than in hydrogene or pure water; consequently their death -in it cannot depend on the simple privation of atmospheric air. - -At the season of the year in which this investigation was carried on, I -was unable to procure frogs or toads. This I regret very much. - -Supposing that cold-blooded animals die in nitrous oxide from positive -changes effected in their blood by the gas, it would be extremely -interesting to notice the apparent alterations taking place in their -organs of respiration and circulation during its action, which -could easily be done, the membranous substance of their lungs being -transparent. The increase or diminution of the irritability of their -muscular fibre, might be determined by comparative galvanic experiments. - - -VIII. _Effects of solution of nitrous oxide in water on Fishes._ - -_a._ A small flounder was introduced into a vessel filled with solution -of nitrous oxide in water over mercury. He remained at rest for ten -minutes and then began to move about the jar in different directions. -In a half an hour he was apparently dying, lying on his side in the -water. He was now taken out, and introduced into a vessel filled with -water saturated with common air, he very soon recovered. - -_b._ Of two large thornbacks,[188] equally brisk and lively. One, A, -was introduced into a jar containing nearly 3 cubic inches of water, -saturated with nitrous oxide, and which previous to its impregnation -had been long boiled; the other, B, was introduced into an equal -quantity of water which had been deprived of air by distillation -through mercury. - -[188] I use the popular name. This fish is very common in every part of -England; it is nearly of the same size and color as the minnow, and is -distinguished from it by two small bony excresences at the origin of -the belly. It is extremely susceptible. - -A, appeared very quiet for two or three minutes, and then began to move -up and down in the jar, as if agitated. In eight minutes his motions -became very irregular, and he darted obliquely from one side of the -jar to the other. In twelve minutes, he became still, and moved his -gills very slowly. In fifteen minutes he appeared dead. After sixteen -minutes he was taken out, but shewed no signs of life. - -B was very quiet for four minutes and half. He then began to move -about the jar. In seven minutes he had fallen on his back, but still -continued to move his gills. In eleven minutes he was motionless; taken -out after thirteen minutes, he did not recover. - -_c._ Of two thornbacks, one, C was introduced into about an ounce of -boiled water in contact with hydrogene, standing over mercury. The -other, D, was introduced into well boiled water saturated with nitrous -oxide, and standing in contact with it over mercury. C lived near -thirteen minutes, and died without being previously much agitated. D -was apparently motionless, after having the same affections as A in the -last experiment, in sixteen minutes. At the end of this time he was -taken out and introduced into common water. He soon began to move his -gills, and in less than a quarter of an hour was so far recovered as to -be able to swim. - -The last experiment was repeated on two smaller thornbacks; that in the -aqueous solution of nitrous oxide lived near seventeen minutes, that in -the water in contact with hydrogene, about fifteen and half. - -The experiments in Res. I. Div. 3, prove the difficulty, and indeed -almost impossibility of driving from water by boiling, the whole of the -atmospheric air held in solution by it; they likewise show that nitrous -oxide by its strong affinity for water, is capable of expelling air -from that fluid after no more can be procured from it by ebullition. - -Hence, if water saturated with nitrous oxide had no positive effects -upon fishes; they ought to die in it much sooner than in water deprived -of air by ebullition. From their living in it rather longer;[189] we -may conclude, that they are destroyed not by privation of atmospheric -air, but from some positive change effected in their blood by the gas. - -[189] A priori I expected that fishes, like amphibious animals would -have been very quickly destroyed by the action of nitrous oxide. - -A long while ago, from observing that the gills of fish became rather -of a lighter red during their death, in the atmosphere; I conjectured -that the disease of which they died, was probably hyperoxygenation -of the blood connected with highly increased animal heat. For not -only is oxygene presented to their blood in much larger quantities in -atmospheric air than in its aqueous solution; but likewise, to use -common language, in a state in which it contains much more _latent -heat_. Without however laying any stress on this supposition, I had the -curiosity to try whether thornbacks would live longest in atmospheric -air or nitrous oxide. In one experiment, they appeared to die in them -nearly in the same time. In another, the fish in nitrous oxide lived -nearly half as long again as that in atmospheric air. - - -IX. _Effects of Nitrous Oxide on Insects._ - -The winged insects furnished with breathing holes, become motionless -in nitrous oxide very speedily; being however possessed of a certain -voluntary power over respiration, they sometimes recover, after having -been exposed to it for some minutes, under the action of atmospheric -air. - -A butterfly was introduced into a small jar, filled with pure nitrous -oxide, over mercury, He struggled a little during the first two or -three seconds; in about seven seconds, his legs became convulsed, and -his wings were wrapt round his body; in about half a minute he was -senseless; taken out after six minutes, he did not recover. - -Another butterfly introduced into hydrogene, became convulsed in about -a quarter of a minute, was senseless in twenty seconds, and taken out -after five minutes, did not revive. - -A large drone, after being in nitrous oxide for a minute and a quarter, -was taken out senseless. After being for some time exposed to the -atmosphere, he began to move, and at last rose on his wings. For some -time, however, he was unable to fly in a straight line; and often -after describing circles in the air, fell to the ground as if giddy. - -A large fly, became motionless in nitrous oxide after being convulsed, -in about half a minute. Another was rendered senseless in hydrogene, in -less than a quarter of a minute. - -A fly introduced into hydrocarbonate, dropt immediately senseless; -taken out after about a quarter of a minute, he recovered; but like the -fly that had lived after exposure to nitrous oxide, was for some time -vertiginous. - -Flies live much longer under water, alcohol, or oil, than in -non-respirable gases, or gases incapable of supporting life. A certain -quantity of air always continues attached in the fluid to the fine -hairs surrounding their breathing holes, sufficient to support life for -a short time. - -Snails and earth-worms, live in nitrous oxide a long while, they die in -it however, much sooner than in water or hydrogene; probably from the -same causes as the amphibious animals. - - -DIVISION II. - - _Of the CHANGES effected in NITROUS OXIDE, and other - GASES, by the RESPIRATION of ANIMALS._ - - -I. _Preliminaries._ - -As soon as I had discovered that nitrous oxide was respirable, and -possessed of extraordinary powers of action on living beings, I was -anxious to be acquainted with the changes effected in it by the venous -blood. To investigate these changes, appeared at first a simple -problem; I soon however found that it involved much preliminary -knowledge of the chemical properties and affinities of nitrous oxide. -After I had ascertained by experiments detailed in the preceding -Researches, the composition of this gas its combinations, and the -physical changes effected by it in living beings, I began my enquiry -relating to the mode of its operation. - -Finding that the residual gas of nitrous oxide after it had been -breathed for some time in silk bags, was chiefly nitrogene, I at first -conjectured that nitrous oxide was decomposed in respiration in the -same manner as atmospheric air, and its oxygene only combined with the -venous blood; the following experiments soon however convinced me of my -error. - - -II. _Absorption of Nitrous Oxide by venous blood. Changes effected in -the blood by different Gases._ - -_a._ Though the laws of the coagulability of the blood are unknown, -yet we are certain that at the moment of coagulation, a perfectly new -arrangement of its principles takes place; consequently, their powers -of combination must be newly modified. The affinities of living blood -can only be ascertained during its circulation in the vessels of -animals. At the moment of effusion from those vessels, it begins to -pass through a series of changes, which first produce coagulation, and -finally its compleat decomposition. - -Consequently, the action of fluid blood upon gates out of the vessels, -will be more analogous to that of circulating blood in proportion as it -is more speedily placed in contact with them. - -_b._ To ascertain the changes effected in nitrous oxide by fluid venous -blood. - -A jar, six inches long and half an inch wide, graduated to,05 cubic -inches, having a tight stopper adapted to it, was filled with -nitrogene, which is a gas incapable of combining with, and possessing -no power of a action upon venous blood. A large orifice was made in the -vein of a tolerably healthy man, and the stopper removed from the jar, -which was brought in contact with the arm so as to receive the blood, -and pressed close against the skin, in such a way as to leave an -orifice just sufficient for the escape of the nitrogene, as the blood -flowed in. When the jar was full, it was closed, and carried to the -pneumatic apparatus, the mercury of which had been previously a little -warmed. A small quantity of the blood was transferred into another -jar to make room for the gas. The remaining quantity equalled exactly -two cubic inches; to this was introduced as speedily as possible, -eleven measures equal to,55 cubic inches of nitrous oxide, which -left a residuum of ¹/₃₂ only, when absorbed by boiled water, and was -consequently, perfectly pure. On agitation, a rapid diminution of the -gas took place. - -In the mass of blood which was opaque, but little change of color could -be perceived; but that portion of it diffused over the sides of the -jar, was evidently of a brighter purple than the venous blood. - -It was agitated for two or three minutes, and then suffered to rest; in -eight minutes it had wholly coagulated; a small quantity of serum had -separated, and was diffused over the coagulum. This coagulum was dark; -but evidently of a more purple tinge than that of venous blood; no gas -had apparently been liberated during its formation. - -The nitrous oxide remaining, was not quite equal to seven measures; -hence, at least four measures of it had been absorbed. - -To ascertain the nature of the residuum, it was necessary to transfer -it into another vessel, but this I found very difficult to accomplish, -on account of the coagulated blood. By piercing through the coagulum -and removing part of it by means of curved iron forceps, I at last -contrived to introduce about 4½ measures of the gas into a small -cylinder, graduated to,25 cubic inches, in which it occupied of course, -nearly 9 measures; when a little solution of strontian was admitted to -these, it became very slightly clouded; but the absorption that took -place did not more than equal half its bulk. Consequently, the quantity -of carbonic acid evolved from the blood, or formed, must have been -extremely minute. - -On the introduction of pure water, a rapid absorption of the gas took -place, and after agitation, not quite 3 measures remained. These did -not _perceptibly_ diminish with nitrous gas; their quantity was too -small to be examined by any other test; but there is reason to suppose -that they were chiefly composed of nitrogene. - -From this experiment, it appeared that nitrous oxide is absorbed when -placed in contact with venous blood; at the same time, that a very -minute quantity of carbonic acid and probably nitrogene is produced. - -_c._ In another similar experiment when nearly half a cubic inch of -nitrous oxide was absorbed by about a cubic inch and three quarters of -fluid blood, the residual gas did not equal more than ⅛, the quantity -absorbed being taken as unity. This fact induced me to suppose that -the absorption of nitrous oxide by venous blood, was owing to a simple -solution of the gas in that fluid, analogous to its solution in water -or alcohol. - -To ascertain if nitrous oxide could be expelled from blood impregnated -with it, by heat; I introduced to 2 cubic inches of fluid blood taken -from the medial vein, about,6 cubic inches of nitrous oxide. After -agitation, in seven minutes nearly,4 were absorbed. In ten minutes, -after the blood had completely coagulated, the cylinder containing it, -was transferred in contact with mercury, into a vessel of solution of -salt in water; this solution was heated and made to boil. During its -ebullition, the whole of the blood became either white or pale brown, -and formed a solid coherent mass; whilst small globules of gas were -given out from it. In a few minutes, about,25 of gas had collected. -After the vessel had cooled, I attempted to transfer this gas into -a small graduated jar in the mercurial apparatus, but in vain; the -mass in the jar was so solid and tough, that I could not remove it. -By transferring it to the water apparatus, I succeeded in displacing -enough of the coagulum to suffer the water to come in contact with -the gas; an absorption of nearly half of it took place; hence, _I -conjecture_, that nitrous oxide had been given out by the impregnated -blood. - -_d_. Some fresh dark coagulum of venous blood, was exposed to nitrous -oxide. A very slight alteration of color took place at the surface of -the blood, perceptible only in a strong light, and a minute quantity of -gas was absorbed. A taper burnt in the remaining gas as brilliantly as -before, hence, it had apparently suffered no alteration. - -_e_. To compare the physical changes effected in the venous blood -by nitrous oxide, with those produced by other gases, I made the -following experiments.—I filled a large phial, containing near 14 cubic -inches, with blood from the vein of the arm of a man, and immediately -transferred it to the mercurial apparatus. Different portions of it -were thrown into small graduated cylinders, filled with the following -gases: nitrogene, nitrous gas, common air, oxygene, nitrous oxide, -carbonic acid, and hydrocarbonate. - -The blood in each of them was successively agitated till it began -to coagulate; and making allowances for the different periods of -agitation, there was no marked difference in the times of coagulation. - -The color of the coagulum in every part of the cylinder, containing -nitrogene, was the same very dark red. When it was agitated so as to -tinge the sides of the jar, it appeared exactly of the color of venous -blood received between two surfaces of glass; no perceptible absorption -of the gas had taken place. - -The blood in nitrous gas was dark, and much more purple on the top than -that in nitrogene. When agitated so as to adhere to the jar as a thin -surface, this purple was evidently deep and bright. An absorption of -rather more than ⅛ of the volume of gas had taken place. - -The blood in oxygene and atmospheric air, were of a much brighter -tinge than that in any of the other gases. On the top, the color was -vermilion, but no perceptible absorption had taken place. - -The coagulum in nitrous oxide, when examined in the mass was dark, -and hardly distinguishable in its color from venous blood; but when -minutely noticed at the surface where it was covered with serum, and in -its diffusion over the sides of the jar, it appeared of a fine purple -red, a tinge brighter than the blood in nitrous gas. An absorption had -taken place in this cylinder, more considerable than in any of the -others. - -In carbonic acid, the coagulum was of a brown red, much darker than the -venous blood, and a slight diminution of gas had taken place. - -In the hydrocarbonate,[190] the blood was red, a shade darker than the -oxygenated blood, and a very slight diminution of the gas[191] was -perceptible. - -[190] The hydrocarbonate employed, was procured from alcohol, by means -of sulphuric acid. This gas contains more carbon, than hydrocarbonate -from water and charcoal. - -[191] The curious fact of the reddening of venous blood by -hydrocarbonate, was discovered by Dr. Beddoes. - -_f._ To human blood that had been saturated with nitrous oxide whilst -warm and constantly agitated for four or five minutes, to prevent its -uniform coagulation, oxygene was introduced; the red purple on the -surface of it, immediately changed to vermilion; and on agitation, -this color was diffused through it. On comparing the tinge with that -of oxygenated blood, no perceptible difference could be observed. -No change of volume of the oxygene introduced, had taken place; and -consequently, no nitrous oxide had been evolved from the blood. - -_g._ Blood, impregnated with nitrous gas, was exposed to oxygene; but -after agitation in it for many minutes, no change of its dark purple -tinge could be observed, though a slight diminution of the oxygene -appeared to take place. - -_h._ Blood that had been rendered vermilion in every part by long -agitation in atmospheric air, the coagulum of which was broken and -diffused with the coagulable lymph through the serum, was exposed to -nitrous oxide; for some minutes no perceptible change of color took -place; but by agitation for two or three hours, it evidently affirmed a -purple tinge, whilst a a slight absorption of gas took place. It never -however, became nearly so dark as venous blood that had been exposed to -nitrous oxide. - -_i._ Blood, oxygenated in the same manner as in the last experiment, -the coagulum of which had been broken, was exposed to nitrous gas. The -surface of it immediately became purple, and by agitation for a few -minutes, this color was diffused through it. A slight diminution of the -gas was observed. On comparing the tinge with that of venous blood that -had been previously exposed to nitrous gas, there was no perceptible -difference. - -_k._ Blood exposed to oxygenated muriatic acid is wholly altered in its -constitution and physical properties, as has been often noticed; the -coagulum becomes black in some parts, and brown and white in others. -Venous blood, after agitation in hydrogene or nitrogene, oxygenates -when exposed to the atmosphere in the same manner as simple venous -blood. I had the curiosity to try whether venous blood exposed to -hydrogene, would retain its power of being oxygenated longer than -blood saturated with nitrous oxide: for this purpose some similar black -coagulum was agitated for some time in two phials, one filled with -hydrogene, the other with nitrous oxide. They were then suffered to -rest for three days at a temperature from about 56° to 63°. After being -opened, no offensive smell was perceived in either of them, the blood -in hydrogene was rather darker than at the time of their exposure, -whilst that in nitrous oxide was of a brighter purple. On being -agitated for some time in the atmosphere, the blood in nitrous oxide -became red, but not of so bright a tinge as oxygenated venous blood. -The color of the blood in hydrogene did not at all alter. - -_l._ To ascertain whether impregnation with nitrous oxide accelerated -or retarded the putrefaction of the blood; I exposed venous blood in -four phials, the first filled with hydrocarbonate, the second with -hydrogene; the third with atmospheric air, and the fourth with nitrous -oxide. Examined after a fortnight, the blood in hydrogene and common -air were both black, and stunk very much; that in hydrocarbonate was -red, and perfectly sweet; that in nitrous oxide appeared purple and had -no disagreeable smell. - -In a second experiment, when blood was exposed for three weeks to -hydrocarbonate and nitrous oxide, that in nitrous oxide was darker than -before and stunk a little; that in hydrocarbonate was still perfectly -sweet. The power of hydrocarbonate to prevent the putrefaction of -animal matters, was long ago noticed by Mr. Watt. - -_m._ Having accidentally cut one of my fingers so as to lay bare a -little muscular fibre, I introduced it whilst bleeding into a bottle of -nitrous oxide; the blood that trickled from the wound evidently became -much more purple; but the pain was neither alleviated or increased. -When however, the finger was taken out of the nitrous oxide and exposed -to the atmosphere, the wound smarted more than it had done before. -After it had ceased to bleed, I inserted it through water into a vessel -of nitrous gas; but it did not become more painful than before. - -From all these observations, we may conclude, - - 1st. That when nitrous oxide is agitated in fluid - venous blood, a certain portion of the gas is - absorbed; whilst the color of the blood changes - from dark red to red purple. - - 2dly. That during the absorption of nitrous oxide by - the venous blood, minute portions of nitrogene and - carbonic acid are produced, either by evolution from - the blood, or from a decomposition of part of the - nitrous oxide. - - 3dly. That venous blood impregnated with nitrous oxide - is capable of oxygenation; and vice versa; that - oxygenated blood may be combined with nitrous oxide. - -When blood separated into coagulum and serum, is exposed to nitrous -oxide, it is most probable that the gas is chiefly absorbed by the -serum. That nitrous oxide however is capable of acting upon the -coagulum, is evident from _d._ In the fluid blood, as we shall see -hereafter, nitrous oxide is absorbed by the attractions of the whole -compound. - - -III. _Of the changes effected in Nitrous Oxide by Respiration._ - -To ascertain whether the changes effected in nitrous oxide by the -circulating blood acting through the moist coats of the pulmonary -veins of living animals, were highly analogous to those produced in -it by fluid venous blood removed from the vessels, I found extremely -difficult. - -I have before observed, that when animals are made to respire nitrous -oxide, a certain absorption of the gas always takes place; but the -smaller animals, the only ones that can be experimented upon in the -mercurial apparatus, die in nitrous oxide so speedily and occasion so -slight a diminution of gas, that I judged it useless to attempt to -analise the residuum of their respiration, which supports flame as well -as pure nitrous oxide, and is chiefly absorbable by water. - -In the infancy of my researches, I often respired nitrous oxide in a -large glass bell, furnished with a breathing tube and stop-cock, and -poised in water saturated with the gas. - -In two or three experiments in which the nostrils being closed after -the exhaustion of the lungs, the gas was inspired from the bell and -respired into it, a considerable diminution was perceived, and by the -test of lime water some carbonic acid appeared to have been formed; but -on account of the absorption of this carbonic acid by the impregnated -water, and the liberation of nitrous oxide from it, it was impossible -to determine with the least accuracy, the quantities of products after -respiration. - -About this time likewise, I often examined the residuum of nitrous -oxide, after it had been respired in silk bags. In these experiments -when the gas had been breathed for a long time, a considerable -diminution of it was observed, and the remainder extinguished flame and -gave a very slight diminution with nitrous gas. But the great quantity -of this remainder as well as other phænomena, convinced me that -though the oiled silk was apparently air-tight when dry, under slight -pressure, yet during the action of respiration, the moist and warm gas -expired, penetrated through it, whilst common air entered through the -wetted surface. - -To ascertain accurately, the changes effected in nitrous oxide by -respiration, I was obliged to make use of the large mercurial airholder -mentioned in Research I. of the capacity of 200 cubic inches. The upper -cylinder of it was accurately balanced so as to be constantly under the -pressure of the atmosphere. To an aperture in it, a stop-cock having -a very large orifice was adapted, curved and flattened at its upper -extremity, so as to form an air-tight mouth-piece. - -By accurately closing the nose, and bringing the lips tight on the -mouth-piece, after a few trials I was able to breathe oxygene or common -air in this machine for two minutes or two minutes and half, without -any other uneasy feeling than that produced by the inclination of the -neck and chest towards the cylinder. The power of uniformly exhausting -the lungs and fauces to the same extent, I did not acquire till after -many experiments. At last, by preserving exactly the same posture -after exhaustion of the lungs before the inspiration of the gas to be -experimented upon, and during its compleat expiration, I found that I -could always retain nearly the same quantity of gas in the bronchial -vessels and fauces; the difference in the volume expired at different -times, never amounting to a cubic inch and half. - -By connecting the conducting pipe of the mercurial airholder, during -the respiration of the gas, with a small trough of mercury by means of -a curved tube, it became a perfect and excellent breathing machine. -For by exerting a certain pressure on the airholding cylinder, it was -easy to throw a quantity of gas after every inspiration or expiration, -into tubes filled with mercury standing in the trough. In these tubes -it could be accurately analised, and thus the changes taking place at -different periods of the process ascertained. - -Whenever I breathed pure nitrous oxide in the mercurial airholder, -after a compleat voluntary exhaustion of my lungs, the pleasurable -delirium was very rapidly produced, and being obliged to stoop on the -cylinder, the determination of blood to my head from the increased -arterial action in less than a minute became so great, as often to -deprive me of voluntary power over the muscles of the mouth. Hence, I -could never rely on the accuracy of any experiment, in which the gas -had been respired for more than three quarters of a minute. - -I was able to respire the gas with great accuracy for more than half -a minute; it at first, rather increasing than diminishing the power -of volition; but even in this short time, very strong sensations -were always produced, with sense of fulness about the head, somewhat -alarming; a feeling which hardly ever occurs to me when the gas is -breathed in the natural posture. - -In all the numerous experiments that I made on the respiration of -nitrous oxide in this way, a very considerable diminution of gas always -took place; and the diminution was generally apparently greater to the -eye during the first four or five inspirations. - -The residual gas of an experiment was always examined in the following -manner. After being transferred through mercury into a graduated -cylinder, a small quantity of concentrated solution of caustic potash -was introduced to it, and suffered to remain in contact with it for -some hours; the diminution was then noted, and the quantity of gas -absorbed by the potash, judged to be carbonic acid. To the remainder, -twice its bulk of pure water was admitted. After agitation and rest for -four or five hours, the absorption by this was noticed, and the gas -absorbed considered as nitrous oxide. The residual unabsorbable gas -was mingled over water with twice its bulk of nitrous gas; and by this -means, its composition, whether it consisted wholly of nitrogene, or of -nitrogene mingled with small quantities of oxygene, ascertained. - -From a number of experiments made at different times on the respiration -of nitrous oxide, I select the following as the most accurate. - -E. 1. At temperature 54°, I breathed 102 cubic inches of nitrous oxide, -which contained near ¹/₅₀ common air, for about half a minute, seven -inspirations and seven expirations being made. After every expiration, -an evident diminution of gas was perceived; and when the last full -expiration was made, it filled a space equal to 62 cubic inches. - -These 62 cubic inches analised, were found to consist of - - Carbonic acid 3,2 - Nitrous oxide 29,0 - Oxygene 4,1 - Nitrogene 25,7 - ———— - 62,0 - ———— - -Hence, accounting for the two cubic inches of common air previously -mingled with the nitrous oxide, 71 cubic inches had disappeared in this -experiment. - -In the last respirations, the quantity of gas was so much diminished, -as to prevent the full expansion of the lungs; and hence the apparent -diminution was very much less after the first four inspirations. - -E. 2. At temperature 47°, I breathed 182 cubic inches of nitrous oxide, -mingled with 2½ cubic inches of atmospheric air, which previously -existed in the airholder, for near 40 seconds; having in this time -made 8 respirations. The diminution after the first full inspiration, -appeared to a by-stander nearly uniform. When the last compleat -expiration was made, the gas filled a space equal to 128 cubic inches, -the common temperature being restored. These 128 cubic inches analised, -were found to consist of - - Carbonic acid 5,25 - Nitrous oxide 88,75 - Oxygene 5,00 - Nitrogene 29,00 - -Consequently, in this experiment, 93,25 cubic inches of nitrous oxide -had disappeared. - -In each of these experiments, the cylinder was covered with condensed -watry vapor exactly in the same manner as if common air had been -breathed in it. It ought to be observed that, E. 1. was made in the -morning, four hours and half after a moderate breakfast; whereas, E. -2. was made but an hour and quarter after a plentiful dinner; at which -near three fourths of a pint of table-beer had been drank. - -From these experiments we learn, that nitrous oxide is rapidly -absorbed by the venous blood, through the moist coats of the pulmonary -veins. But as after a compleat voluntary exhaustion of the lungs, -much residual air must remain in the bronchial vessels and fauces, -as appears from their incapability of compleatly collapsing, it is -evident that the gas expired after every inspiration of nitrous oxide -mast be mingled with different quantities of the residual gas of the -lungs;[192] whilst after a complete expiration, much of the unabsorbed -nitrous oxide must remain as residual gas in the lungs. Now when -a complete expiration is made after the breathing of atmospheric -air, it is evident that the residual gas of the lungs consists of -nitrogene,[193] mingled with small portions of oxygene and carbonic -acid. And these are the only products found after the respiration of -nitrous oxide. - -[192] By lungs, I mean in this place, all the internal organs of -respiration. - -[193] Because these products are formed during the respiration of -common air. - -To ascertain whether these products were partially produced, during -the process of respiration, as I was inclined to believe from the -experiments in the last section, or whether they were wholly the -residual gases of the lungs, I found extremely difficult. - -I at first thought of breathing nitrous oxide immediately after my -lungs had been filled with oxygene; and to compare the products -remaining after the full expiration, with those produced after a full -expiration of pure oxygene; but on the supposition that oxygene and -nitrous oxide, when applied together to the venous blood, must effect -changes in it different from either of them separately, the idea was -relinquished. - -I attempted to inspire nitrous oxide, after having made two -inspirations and a complete expiration of hydrogene; but in this -experiment the effects of the hydrogene were so debilitating, and the -consequent stimulation by the nitrous oxide so great, as to deprive -me of sense. After the first three inspirations, I lost all power of -standing, and fell on my back, carrying in my lips the mouth-piece -separated from the cylinder, to the great alarm of Mr. Patrick Dwyer, -who was noting the periods of inspiration. - -Though experiments on successive inspirations of pure nitrous oxide -might go far to determine whether or no any nitrogene, carbonic acid -and oxygene were products of respiration, yet I distinctly saw that it -was impossible in this way to ascertain their quantities, supposing -them produced, unless I could first determine the capacity of my lungs; -and the different proportions of the gases remaining in the bronchial -vessels after a compleat expiration, when atmospheric air had been -respired. - -In some experiments (that I made on the respiration of hydrogene, -with a view to determine whether carbonic acid was _produced_ by -the combination of carbon loosely combined in the venous blood, -with the oxygene respired, or whether it was simply _given out_ as -excrementitious by this blood) I found, without however being able to -solve the problem I had proposed to myself, that in the respiration of -pure hydrogene, little or no alteration of volume took place; and that -the residual gas was mingled with some nitrogene, and a little oxygene -and carbonic acid. - -From the comparison of these facts with those noticed in the last -section and in R. III. Div. I. there was every reason to suppose -that hydrogene was not absorbed or altered when respired: but only -mingled with the residual gases of the lungs. Hence, by making a full -expiration of atmospheric air, and afterwards taking six or seven -respirations of hydrogene in the mercurial airholder, and then making -a compleat expiration, I conjectured that the residual gas and the -hydrogene would be so mingled, as that nearly the same proportions -should remain in the bronchial vessels, as in the airholder. By -ascertaining these proportions and calculating from them, I hoped to be -able to ascertain with tolerable exactness, the capacity of my fauces -and bronchia, as well as the composition of the gas remaining in them, -after a complete expiration of common air. - - -IV. _Respiration of Hydrogene._ - -The hydrogene that I employed, was procured from the decomposition of -water by means of clean iron filings and diluted sulphuric and muriatic -acids. It was breathed in the same manner as nitrous oxide, in the -large mercurial airholder. - -After a compleat voluntary exhaustion of my lungs in the usual -posture, I found great difficulty in breathing hydrogene for so -long as half a minute, so as to make a compleat expiration of it. It -produced uneasy feelings in the chest, momentary loss of muscular -power, and sometimes a transient giddiness. - -In some of the experiments that I made; on account of the giddiness, -the results were rendered inconclusive, by my removing my mouth from -the mouth-piece after expiration, before the assistant could turn the -stop-cock. - -The purity of the hydrogene was ascertained immediately before the -experiment by the test of nitrous gas, and by detonation with oxygene -or atmospheric air; generally 12 measures of atmospheric air were fired -with 4 of the hydrogene, and if the diminution was to ten or a little -more, the gas was judged to be pure. - -After the experiment, when the compleat expiration had been made and -the common temperature restored; the volume of the gas was noticed, -and then a small quantity of it thrown into the mercurial apparatus by -means of the conducting tube, to be examined. The carbonic acid was -separated by from it by means of solution of potash or strontian; the -quantity of oxygene it contained, was ascertained by means of nitrous -gas of known composition; the superabundant nitrous gas was absorbed -by solution of muriate of iron; and the proportions of hydrogene -and nitrogene in the remaining gas, discovered by inflammation with -atmospheric air or oxygene in the detonating tube by the electric spark. - -_a._ The two following experiments made upon quantities of hydrogene, -equal to those of the nitrous oxide respired in the experiments in the -last section, are given as the most accurate of five. - -E. 1. I respired at 59° 102 cubic inches of hydrogene apparently pure, -for rather less than half a minute, making in this time seven quick -respirations. - -After the complete expiration, when the common temperature was -restored, the gas occupied a space equal to 103 cubic inches nearly. -These analised were found to consist of - - Carbonic acid 4,0 - Oxygene 3,7 - Nitrogene 17,3 - Hydrogene 78,0 - ————— - 103,0 - -Now as in this experiment, the gas was increased in bulk only a cubic -inch; supposing that after the compleat expiration the gas in the -lungs, bronchia and fauces was of nearly similar composition with -that in the airholder, and that no hydrogene had been absorbed by the -blood, it would follow that 24 cubic inches of hydrogene remained in -the internal organs of respiration, and consequently, by the rule of -proportion, about 7,8 of the mixed residual gas of the common air. -And then the whole quantity of residual gas of the lungs, supposing -the temperature 59°, would have been 31,8 cubic inches; but as its -temperature was nearly that of the internal parts of the body, 98°, it -must have filled a greater space; calculating from the experiments of -Guyton and Vernois,[194] about 37,5[195] cubic inches. - -From the increase of volume, it would appear that a minute quantity -of gas had been generated during the respiration, and this was, as we -shall see hereafter, most probably carbonic acid.[196] Likewise there -is reason to suppose, that a little of the residual oxygene must have -been absorbed. Making allowances for those circumstances, it would -follow, that the 37,5 cubic inches of gas remaining in my lungs, after -a compleat expiration of atmospheric air at animal heat 98°, equal to -31,8 cubic inches at 59°, were composed of - - Nitrogene 21,9 - Carbonic acid 4,9 - Oxygene 5,0 - ———— - 31,8 - -[194] Annales de Chimie, vol. 1, page 279. - -[195] This is only an imperfect approximation; the ratio of the -increase of expansibility of gases to the increase of temperature, has -not yet been ascertained. It is probable that the expansibility of -gases is altered by their mixture. - -[196] For there is no reason to suppose the production of nitrogene. - -E. 2. I respired for near a half a minute in the mercurial airholder at -61°, 182 cubic inches of hydrogene; having made during this time, six -long inspirations. After the last expiration, the gas filled a space -nearly equal to 184 cubic inches, and analised, was found to consist of - - Carbonic acid 4,8 - Oxygene 4,6 - Nitrogene 21,0 - Hydrogene 153,6 - ————— - 184,0 - -Now in this experiment, reasoning in the same manner as before, 28,4 -cubic inches of hydrogene must have remained in the lungs, and likewise -5,5 of the atmospheric residual gas. Consequently, the whole residual -gas was nearly equal to 34 cubic inches at 61°, which at 98° would -become about 40,4 cubic inches. And reasoning as before, it would -appear from this experiment, that the quantity of gas remaining in my -lungs after a compleat voluntary respiration, equalled at 98, about 40 -cubic inches, and at 61°, 34 nearly: making the necessary corrections; -that after common air had been breathed, these 34 cubic inches -consisted of - - Carbonic acid 4,1 - Oxygene 5,5 - Nitrogene 24,4 - -_b._ It would have been possible to prove the truth of the postulate on -which the experiments were founded, by respiring common air or oxygene -after the compleat expiration of the hydrogene, for the same time as -the hydrogene was respired and in equal quantities. - -For if portions of hydrogene were found in the airholder equal to -those of the residual gases in the two experiments, it would prove -that a _uniform_ mixture of residual gas with the gas inspired, was -produced by the respiration. That this mixture must have taken place, -appeared, however, so evident from analogous facts, that I judged the -experimental proof unnecessary. - -Indeed, as most gases, though of different specific gravities, when -brought in contact with each other, assume some sort of union, it -is more than probable, that gas inspired into the lungs, from being -placed in contact with the residual gas on such an extensive surface, -must instantly mingle with it. Hence, possibly one deep inspiration -and compleat expiration of the whole of a quantity of hydrogene, will -be sufficient to determine the capacity of the lungs after compleat -voluntary exhaustion, and the nature of the residual air. - -That two inspirations are sufficient, appears probable from the -following experiment. - -E. 3. After a compleat voluntary expiration of common air, I made two -deep inspirations of 141 cubic inches of hydrogene. After the compleat -expiration, they filled a space equal to rather more than 142 cubic -inches, and analised, were found to consist of - - Carbonic acid 3,1 - Oxygene 4,5 - Nitrogene 18,8 - Hydrogene 115,6 - ————— - 142,0 - -Now calculating on the exhausted capacity of my lungs from this -experiment, supposing uniform mixture, they would contain after -expiration of common air, about 30,7 cubic inches at 58°, equal to 36 -at 98°, composed of about - - Nitrogene 20,9 - Oxygene 5,8 - Carbonic acid 4,0 - ———— - 30,7 - -One should suppose a priori that in this experiment much less of the -residual oxygene of the lungs must have been absorbed, than in Expts. 1 -and 2; yet there is no very marked difference in the portions evolved. -That a tolerably accurate mixture took place, appears from the quantity -of nitrogene. The smaller quantity of carbonic acid is an evidence in -favour of its evolution from the venous blood. - -_c._ It is reasonable to suppose that the pressure upon the residual -gas of the exhausted lungs, must be nearly equal to that of the -atmosphere. But as aqueous vapour is perpetually given out by the -exhalents, and perhaps evolved from the moist coats of the pulmonary -vessels, it is likely that the residual gas is not only fully saturated -with moisture at 98°, but likewise impregnated with uncombined vapor; -and hence its volume enlarged beyond the increment of expansion of -temperature. - -Considering all these circumstances, and calculating from the mean -of the three experiments on the composition of the residual gas, I -concluded, - -1st. That the exhausted capacity of my lungs was equal to about 41 -cubic inches. - -2dly. That the gas contained in my bronchial vessels and fauces, after -a compleat expiration of atmospheric air, was equal to about 32 cubic -inches, its temperature being reduced to 55°. - -3dly. That these 32 cubic inches were composed of about - - Nitrogene 23,0 - Carbonic acid 4,1 - Oxygene 4,9 - -_d._ In many experiments made in the mercurial airholder on the -capacity of my lungs under different circumstances, I found that I -threw out of my lungs by a full forced expiration at temperatures from -58° to 62° - - cub. cub. - in. in. - After a full voluntary inspiration, from 189 to 191 - After a natural inspiration, from 78 to 79 - After a natural expiration, from 67 to 68 - -So that making the corrections for temperature, it would appear, that -my lungs in a state of voluntary inspiration, contained about 254 -cubic inches; in a state of natural inspiration about 135; in a state -of natural expiration, about 118; and in a state of forced expiration -41.[197] - -[197] This capacity is most probably below the medium, my chest is -narrow, measuring in circumference, but 29 inches, and my neck rather -long and slender. - -As the exhausted capacity as well as impleted capacity of the internal -organs of respiration must be different in different individuals, -according as the forms and size of their thorax, fauces, and bronchia -are different, it would be almost useless to endeavour to ascertain a -standard capacity. It is however probable, that a ratio exists between -the quantities of air inspired in the natural and forced inspiration, -those expired in the natural and forced expiration, and the whole -capacity of the lungs. If this ratio were ascertained, a single -experiment on the natural inspiration and expiration of common air, -would enable us to ascertain the quantity of residual gas in the lungs -of any individual after a compleat forced expiration.[198] - -[198] Dr. Goodwyn in his excellent work on the connexion of life with -respiration, has detailed some experiments on the capacity of the lungs -after natural expiration. He makes the medium capacity about 109 cubic -inches, which agrees very well with my estimation.—page 27. - - -V. _Additional observations and experiments on the Respiration of -Nitrous Oxide._ - -_a._ Having thus ascertained the capacity of my lungs, and the -composition of the residual gas of expiration, I proceeded to reason -concerning the experiments in section III, on the respiration of -nitrous oxide. - -In Exp. I. nearly 100 cubic inches of nitrous oxide, making the -corrections on account of the common air, were respired for half a -minute. In this time, they were reduced to 62 cubic inches, which -consisted of 3,2 carbonic acid, 29 nitrous oxide, 4,1 oxygene, and 25,7 -nitrogene. - -But, as appears from the last section, there existed in the lungs -before the inspiration of the nitrous oxide, about 32 cubic inches of -gas, consisting of 23 nitrogene, 4,1 carbonic acid, and 4,9 oxygene, -temperature being reduced to 59°. This gas must have been perfectly -mingled with the nitrous oxide during the experiment; and consequently, -the residual gas in the lungs after the experiment, was of the same -composition as that in the airholder. - -Supposing it as before, to be about 32 cubic inches: from the rule of -proportion, they will be composed of - - Nitrous oxide 14,7 - Nitrogene 13,3 - Carbonic acid 1,9 - Oxygene 2,1 - -And the whole quantity of gas in the lungs and the airholder, supposing -the temperature 59°, will equal 94 cubic inches, which are composed of - - Nitrous oxide 43,7 - Nitrogene 39,0 - Carbonic acid 5,2 - Oxygene 6,1 - ———— - 94 - -But before the experiment, the gas in the lungs and airholder equalled -134 cubic inches, and these, reckoning for the common air, were -composed of - - Nitrous oxide 100 - Nitrogene, 24,3 - Carbonic acid 4,1 - Oxygene 5,6 - -Hence, it appears, that 56,3 cubic inches of nitrous oxide were -absorbed in this experiment, and 13,7 of nitrogene produced, either -by evolution from the blood, or decomposition of the nitrous oxide. -The quantities of carbonic acid and oxygene approach so near to those -existing after the respiration of hydrogene, that there is every reason -to believe that no portion of them was produced in consequence of the -absorption, or decomposition of the nitrous oxide. - -_b._ In Exp. 2, calculating in the same manner, before the first -inspiration, a quantity of gas equal to 216,5 cubic inches at 47°, -existed in the lungs and airholder, and these 216,5 cubic inches were -composed of - - Nitrous oxide, 182,0 - Nitrogene 24,9 - Carbonic acid 4,1 - Oxygene 5,5 - —————— - 216,5 - -After the compleat expiration, 160 cubic inches remained in the lungs -and airholder, which was composed of - - Nitrous oxide 110,6 - Nitrogene 36,3 - Carbonic acid 6,8 - Oxygene 6,3 -Hence, it appears, that 71,4 cubic inches of nitrous oxide were -absorbed in this experiment, and about 12 of nitrogene produced. The -quantity of carbonic acid and oxygene is rather greater than that which -existed in the experiments on hydrogene. - -_c._ From these estimations, I learned that a small quantity of -nitrogene was produced during the absorption of nitrous oxide in -respiration. It remained to determine, whether this nitrogene owed its -production to evolution from the blood, or to the decomposition of a -portion of the nitrous oxide. - -Analogical evidences were not in favour of the hypothesis of -decomposition. It was difficult to suppose that a body requiring the -temperature of ignition for its decomposition by the most inflammable -bodies, should be partially absorbed and partially decompounded at 98°, -by a fluid apparently possessed of uniform attractions. - -It was more easy to believe, that from the immense quantity of -nitrogene taken into the blood in nitrous oxide; the system soon -became overcharged with this principle, which not being wholly -expended in new combinations during living action, was liberated in -the aëriform state by the exhalents, or through the moist coats of the -veins. - -Now if the last rationale were true, it would follow, that the -quantity of nitrogene produced in respiration, ought to be increased -in proportion as a greater quantity of nitrous oxide entered into -combination with the blood. - -_d._ To ascertain whether this was the case, I made after full -voluntary exhaustion of my lungs, one full voluntary inspiration and -expiration of 108 cubic inches of nitrous oxide. After this, it filled -a space nearly equal to 99 cubic inches. The quantities of carbonic -acid and oxygene in these were not determined; but by the test of -absorption by water, they appeared to contain only 18 nitrogene; which -is very little more than should have been given from the residual gas -of the lungs. - -In a second experiment, I made two respirations of 108 cubic inches -of nitrous oxide nearly pure. The diminution was to 95. On analysing -these 95, I found to my great surprise, that they contained only 17 -nitrogene. Hence, I could not but suspect some source of error in the -process. - -I now introduced into a strong new silk bag, the sides of which were -in perfect contact, about 8 quarts of nitrous oxide. From the mode of -introduction, this nitrous oxide must have been mingled with a little -common air, not however sufficient to disturb the results. - -I then adapted a cork cemented to a long curved tube to my right -nostril; the tube was made to communicate with the water apparatus; -and the left nostril being accurately closed, and the mouth-piece of -the silk bag tightly adapted to the lips, I made a full expiration -of the common air of my lungs, inspired nitrous oxide from the bag, -and by carefully closing the mouth-piece with my tongue, expired it -through the curved tube into the water apparatus. In this way, I made -nine respirations of nitrous oxide. The expired gas of the first -respiration was not preserved; but part of the gas of the second, -third, fifth, seventh and ninth, were caught in seperate graduated -cylinders. The second, analised by absorption, consisted of about 29 -absorbable gas, which must have been chiefly nitrous oxide; and 17 -unabsorbable gas, which must have been chiefly nitrogene; and the third -of 22 absorbable gas, and 8 unabsorbable. The fifth was composed of 27 -to 6; the seventh of 23 to 7, and the ninth of 26 to 11. - -_e._ Though the results of these experiments were not so conclusive as -could be wished; yet, comparing them with those of the experiments in -section III. it seemed reasonable to conclude, that the production of -nitrogene was increased, in proportion as the blood became more fully -impregnated with nitrous oxide. - -From this conclusion, compared with the phænomenon noticed in section -2, and in Div. I. section 4, I am induced to believe that the -production of nitrogene during the respiration of nitrous oxide, is -not owing to the decomposition of part of the nitrous oxide, in the -aëriform state _immediately_ by the attraction of the red particles -of venous blood for its oxygene; but that it is rather owing to a new -arrangement produced in the principles of the impregnated blood, during -circulation; from which, becoming supersaturated with nitrogene, it -gives it out through the moist coats of the vessels. - -For if any portion of nitrous oxide were decomposed immediately by the -red particles of the blood, one should conjecture, that the quantity of -nitrogene produced, ought to be greater during the first inspirations, -before these particles became fully combined with condensed oxygene. -If on the contrary, the whole of the nitrogene and oxygene of the -nitrous oxide were both combined with the blood, and carried through -the pulmonary veins and left chamber of the heart to the arteries; -then, supposing the oxygene chiefly expended in living action, whilst -the nitrogene was only partially consumed in new combinations, it -would follow, that the venous blood of animals made to breathe nitrous -oxide, hyper-saturated with nitrogene, must be different from common -venous blood; and this we have reason to believe from the phænomena in -Div. I. section 4, is actually the case. - -_f._ Besides the nitrogene generated during the respiration of nitrous -oxide, we have noticed the evolution of other products, carbonic -acid,[199] and water. - -[199] The oxygene as we have before noticed, most probably wholly -existed in the residual gas. - -Now as nearly equal quantities of carbonic acid are produced, whether -hydrogene or nitrous oxide is respired, provided the process is carried -on for the same time; there is every reason to believe, as we have said -before, that no part of the carbonic acid produced, is generated from -the immediate decomposition of nitrous oxide by carbon existing in the -blood. - -Consequently, in these experiments, it must be either evolved from the -venous blood; or formed, by the slow combination of the oxygene of the -residual air of respiration with the charcoal of the blood. - -But if it was produced by the decomposition of residual atmospheric -air, it would follow, that its volume must be much less than that -of the oxygene of the residual air, which had disappeared; for some -of this oxygene must have been _absorbed_ by the blood, and during -the conversion of oxygene into carbonic acid by charcoal, a slight -diminution of volume is produced. - -In the experiments when nitrous oxide and hydrogene were respired for -about half a minute, the medium quantity of carbonic acid produced, was -5,6 cubic inches nearly. - -Now we will assume, that the quantity of carbonic acid produced, is -in the ratio of the oxygene diminished; and there is every reason to -believe, that in the expiration of atmospheric air, the expired air and -the residual air are nearly of the same composition. - -Hence, no more carbonic acid can remain in the lungs or be produced -from the residual gas after the compleat expiration of common air, -than that which can be generated from a volume of atmospheric air -equal to the residual gas of the lungs. - -The residual gas of the lungs, after compleat expiration, equals at -55°, 32 cubic inches, and 32 cubic inches of common air contain 8.6 -cubic inches of oxygene. - -But in the experiments on the respiration of hydrogene, not only -5.6 cubic inches of carbonic acid were produced, but more than 4 of -residual oxygene remained unabsorbed. - -Hence it appears impossible that all the carbonic acid evolved from the -lungs during the respiration of nitrous oxide or hydrogene could have -been produced by the combination of charcoal in the venous blood with -residual atmospheric oxygene: there is consequently every reason to -believe that it is wholly or partially liberated from the venous blood -through the moist coats of the vessels. - -_g._ The water carried out of the lungs in solution by the expired gas -of nitrous oxide, could neither have been wholly or partially formed -by the decomposition of nitrous oxide. The coats of the vessels in the -lungs, and indeed in the whole internal surface of the body, are always -covered with moisture, and the solution of part of this moisture by -the inspired heated gas, and its deposition by the expired gas, are -sufficient causes for the appearance of the phænomenon. - -There are no reasons for supposing that any of the residual atmospheric -oxygene is immediately combined with fixed or nascent hydrogene, or -hydrocarbonate, in the venous blood at 98°, by slow combustion, and -consequently none for supposing that water is immediately formed in -respiration. - -The evolution of water from the vessels in the lungs, is almost certain -from numerous analogies. - -_h._ As from the experiments in section II. it appeared that nitrous -oxide was capable of being combined with oxygenated blood, and vice -versa, blood impregnated with nitrous oxide capable of oxygenation; I -was curious to ascertain what changes would be effected in nitrous -oxide when it was respired, mingled with atmospheric air or oxygene. -For this purpose, without making a very delicate experiment, I breathed -in the large mercurial airholder about 112 cubic inches of nitrous -oxide, mingled with 44 of common air, for near half a minute, in the -usual mode. The gas, after expiration, filled a space nearly equal to -119. I did not exactly ascertain the composition of the residual gas; -it supported flame rather better than common air, and after the nitrous -oxide was absorbed, gave much less diminution with nitrous gas than -atmospheric air. - -_i._ I breathed a mixture of four quarts of nitrous oxide with three -quarts of hydrogene, in a dry silk bag, for near a minute; an evident -diminution was produced; but on account of the mode of experimenting it -was impossible to determine the quantity of nitrous oxide absorbed, or -the exact nature of the products. When a taper was introduced into a -little of the residual gas, it inflamed with a very feeble explosion. -Now a mixture of 4 parts nitrous oxide and 3 hydrogene, detonates when -inflamed with very great violence. - -_k._ Nitrous oxide can be respired without danger by the human animal -for a much longer time than that required for the death of the smaller -quadrupeds in it. - -I have breathed it two or three times in a considerable state of -purity, in a dry silk bag, for four minutes and quarter and four -minutes and half: some diseased individuals have respired it for -upwards of five minutes. - -In the infancy of my experiments, from general appearances, I thought -that the proportion of nitrous oxide absorbed in respiration was -greater in the first inspirations than the last; but this I have -since found to be a mistake. In the last respirations the apparent -absorption is indeed less; but this is on account of the increased -evolution of nitrogene from the blood. When nitrous oxide is respired -for a long time, the last inspirations are always fuller and quicker -than the first; but the consumption by the same individual is nearly in -the ratio of the time of respiration. Three quarts, i. e. about 174 -cubic inches, are consumed so as to be unfit for respiration, by an -healthy individual with lungs of moderate capacity, in about a minute -and quarter; six quarts, or 348 cubic inches, last generally for two -minutes and half or two minutes and three quarters; eight quarts, or -464 cubic inches, for more than three minutes and half; and twelve, or -696 cubic inches, for nearly five. - -The quantities of nitrous oxide absorbed by the same individual, will, -as there is every reason to suppose, be different under different -circumstances, and will probably be governed in some measure by the -state of the health. It is reasonable to suppose, that the velocity of -the circulation must have a considerable influence on the absorption -of nitrous oxide; probably in proportion as it is greater a larger -quantity of gas will be consumed in equal times. - -I am inclined from two or three experiments, to believe that -nitrous oxide is absorbed more rapidly after hearty meals or during -stimulation from wine or spirits, than at other times. As its -absorption appears to depend on a simple solution in the venous blood; -probably diminution of temperature will increase its capability of -being absorbed. - -_l._ The quantities of nitrous oxide absorbed by different individuals, -will probably be governed in some measure by the size of their lungs -and the surface of the blood vessels, all other circumstances being the -same. - -From the observations that I have been able to make on the absorption -of nitrous oxide, as compared with the capacity of the lungs, the range -of the consumption of different individuals does not extend to more -than a pint, or 30 cubic inches at the maximum dose. - -We may therefore conclude, that the medium consumption of nitrous oxide -by the respiration of different individuals, is not far from two cubic -inches, or about a grain every second, or 120 cubic inches, or 60 -grains every minute. - -_m._ When nitrous oxide is breathed in tight silk bags, towards the end -of the experiment as the internal surface becomes moist, as I have -before mentioned, a certain quantity of common air penetrates through -it and becomes mixed with the residual gas of the experiment; but this -quantity is always too small to destroy any of the effects of the -nitrous oxide. The residual gas of the common air, the nitrogene and -carbonic acid produced in the process, and the residuum of the admitted -atmospheric air, hardly ever amount after the experiment, to one half -of the volume of the nitrous oxide absorbed. There is consequently, a -perfect propriety in successively inspiring and expiring the whole of -a given quantity of nitrous oxide, till it is nearly consumed. In the -respiration of nitrous oxide as the gas is absorbed and not decomposed, -little will be gained in effect, by perpetually inspiring and expiring -new portions, whilst an immense quantity of gas will be idly wasted, -and this circumstance, considering the expence of the substance, is of -importance. - - -VI. _On the respiration of Atmospheric Air._ - -Having thus ascertained the absorption of nitrous oxide in respiration, -and the evolution of nitrogene and carbonic acid from the lungs during -its absorption: considering atmospheric air as a compound in which -principles identical with those in nitrous oxide existed, though in -different quantities and looser combination, I was anxious to compare -the changes effected in this gas by respiration, with those produced in -nitrous oxide and oxygene; particularly as they are connected with the -health and life of animals. - -The ingenious experiments of Lavoisier and Goodwyn, prove the -consumption of oxygene in respiration, and the production of carbonic -acid. From many experiments on the respiration of common air, Dr. -Priestly suspected that a certain portion of nitrogene, as well as -oxygene, was absorbed by the venous blood. - -_b._ In the following experiments on the respiration of atmospheric -air in the mercurial airholder; the composition of the gas before -inspiration and after expiration, was ascertained in the following -manner. - -Forty measures of it were agitated over mercury in solution of -caustic potash, and suffered to remain in contact with it for two or -three hours. The diminution was noted, and the gas absorbed judged -to be carbonic acid. Twenty measures of the gas, freed from carbonic -acid, were mingled with thirty of nitrous gas, in a tube of,5 inches -diameter; they were not agitated,[200] but suffered to rest for an hour -or an hour and half, when the volume occupied by them was noticed: and -50-_m_ the volume occupied, divided by 3 considered as the oxygene _x_, -and 20-_x_ considered as the nitrogene. - -[200] When they are agitated, a greater proportion of nitrous gas is -absorbed, condensed in the nitric acid by the water; and to find the -oxygene, - - (50 - _m_) (50 - _m_) - _x_ = —————————— or ————————— . - (3,4) (3,5) - - -_c._ To ascertain the changes effected in atmospheric air by single -inspirations, - -I made, after a compleat voluntary exhaustion of my lungs, at -temperature 61°, one inspiration and expiration of 141 cubic inches of -atmospheric air. After expiration, they filled a space equal to 139 -cubic inches nearly. These 139 cubic inches analised were found to -consist of - - Nitrogene 101 - Oxygene 32 - Carbonic acid 6 - -The 141 cubic inches before inspiration, were composed of 103 -nitrogene, 1 carbonic acid and 37 oxygene. The time taken to perform -the inspiration and full expiration, was nearly a quarter of a minute. - -I repeated this experiment seven or eight times, and the quantity of -oxygene absorbed was generally from 5 to 6 cubic inches, the carbonic -acid formed from 5 to 5,5, and the quantity of nitrogene apparently -diminished by from 1 to 3 cubic inches. - -E. 2. I made, after a voluntary expiration of common air, one -inspiration and full expiration of 100 cubic inches of atmospheric air. -It was diminished nearly to 98¾ or 99 cubic inches, and analised, was -found to consist of - - Nitrogene 71,7 - Oxygene 22,5 - Carbonic acid 4,5 - -This experiment I likewise repeated four or five times, with very -little difference of result, and there always seemed to be a small -diminution of nitrogene. I made no corrections on account of the -residual air of the lungs in these processes, because there was every -reason to suppose that it was always of similar composition. - -_c._ Before I could ascertain whether similar changes were effected -in atmospheric air, by natural inspirations as by forced ones, I -was obliged to practise respiration in the mercurial airholder, by -differing the conducting tube to communicate with the atmosphere till I -had attained the power of breathing in it naturally, without labor or -attention; I then found by a number of experiments, that I took into my -lungs at every natural inspiration, about 13 cubic inches of air, and -that I threw out of my lungs at every expiration,[201] rather less than -this quantity; about 12¾ cubic inches. - -[201] The diminution of air by single inspirations, was particularly -noticed by Dr. Goodwyn. - -The mean composition of the 13 cubic inches of air inspired, was - - cub. in. - Nitrogene 9,5 - Oxygene 3,4 - Carbonic acid 0,1 - -That of the 12,7 of air expired - - Nitrogene 9,3 - Oxygene 2,2 - Carbonic acid 1,2 - -These results I gained from more than 20 experiments, so that I could -not possibly entertain any doubt of this accuracy. - -I found, by making a person observe my respirations when I was -inattentive to the process, that I made about 26 or 27 natural -inspirations in a minute. So that calculating from the above -estimations, it would follow, that 31,6 cubic inches of oxygene were -consumed, and 5,2 inches of nitrogene lost in respiration every minute, -whilst 26,6 cubic inches of carbonic acid were produced. - -To collect the products of a great number of natural expirations so -as to ascertain whether their composition corresponded with the above -accounts, I proceeded in the following manner. - -I fastened my lips tight on the mouth-piece of the exhausted airholder, -and suffering my nostrils to remain open, inspired naturally through -them, throwing the expired air through my mouth into the airholder. - -In many experiments, I found that in about a half a minute, I made in -this way 14 or 15 expirations. The mean quantity of air collected was -171 cubic inches, and consisted of - - cub. in. - Nitrogene 128 - Oxygene 29 - Carbonic acid 14 - -Comparing these results with the former ones, we find the mean -quantities of air respired in equal terms rather less; but the -proportions of carbonic acid, nitrogene and oxygene in the respired -air, nearly identical. - -_e._ To ascertain the changes effected in a given quantity of -atmospheric air by continued respirations, I breathed after a compleat -expiration, at temperature 63°, 161 cubic inches of air for near a -minute, making in this time, 19 deep inspirations. After the compleat -expiration, which was very carefully made, the gas filled a space -nearly equal to 152 cubic inches, so that 9 cubic inches of gas had -disappeared. - -The 152 cubic inches analised, were found to consist of - - cub. in. - Nitrogene 111,6 - Oxygene 23, - Carbonic acid, 17,4 - -The 161 cubic inches before inspiration, were composed of - - cub. in. - Nitrogene 117,0 - Oxygene 42,4 - Carbonic acid 1,6 - -But the residual gas in the lungs before the experiment, was of -different composition from that remaining in the lungs after the -experiment. Making corrections on account of this circumstance, as in -section IV. it appears that about 5,1 of nitrogene were absorbed in -respiration, 23,9 of oxygene consumed, and 12 of carbonic acid produced. - -I repeated this experiment three times; in each experiment the -diminution after respiration, was nearly the same; and the residual -gas making the necessary allowances, of similar composition. So that -supposing the existence of no source of error in the experiments from -which the quantity and composition of the residual gas of the lungs -were estimated in section IV. the absorption of nitrogene by the venous -blood, appears almost demonstrated. - -_f._ To compare the changes effected in atmospheric air by respiration -of the smaller quadrupeds, with those in the experiments just detailed, -I introduced into a jar of the capacity of 20 cubic inches filled -with mercury in the mercurial trough, 15 cubic inches of atmospheric -air which had been deprived of its carbonic acid by long exposure, to -solution of potash. - -Temperature being 64°, a healthy small mouse was quickly passed under -the mercury into the jar, and suffered to rest on a very thin bit of -cheese, which was admitted immediately after. - -He continued for near 40 minutes without apparently suffering, -occasionally raising himself on his hind legs. At the end of 50 -minutes, he was lying on his side, and in 55 minutes was apparently -dying. He was now carefully taken out through the mercury by the tail, -and exposed before the fire, where he soon recovered. After the cheese -had been carefully removed, the gas in the jar filled a space nearly -equal to 14 cubic inches; so that a diminution of a cubic inch had -taken place. These 14 cubic inches analised, were found to consist of - - cub. in. - Carbonic acid 2,0 - Oxygene 1,4 - Nitrogene 10,6 - -The 15 cubic inches before the experiment, consisted of - - cub. in. - Oxygene 4 - Nitrogene 11 - -Hence it appeared, that 2,6 cubic inches of oxygene had been consumed, -2 cubic inches of carbonic acid produced, and about 0,4 of nitrogene -lost. - -The relation between the quantities of oxygene consumed in this -experiment, and the carbonic acid produced, are nearly the same as -that of those in the experiments just detailed; but the quantity of -nitrogene lost is much smaller. - - -VII. _Respiration of Oxygene._ - -The gases before and after respiration, were analised in these -experiments in the manner described in the last section, except that 3 -of nitrous gas were always employed to one of oxygene. - -E. I. At temperature 53°, after a full forced respiration, I respired -in the mercurial airholder, for half a minute, 102 cubic inches of -oxygene, making seven very long and deep inspirations. After the -compleat expiration, the gases filled a space equal to 93 cubic inches; -these 93 cubic inches analised, were found to consist of - - cub. in. - Carbonic acid 5,9 - Nitrogene 33,8 - Oxygene 53,3 - -The 102 cubic inches before the experiment, were composed of - - cub. in. - Oxygene 78 - Nitrogene 24 - -The residual gas in the lungs before the experiment, was 32 cubic -inches, and composed of about 23 nitrogene, 4,1 carbonic acid, and 4,9 -oxygene, Section IV. The residual gas after expiration, was composed of -18,2 oxygene, 2 carbonic acid, and 11,8 nitrogene. - -Hence the whole of the gas in the lungs and airholder before -inspiration, was 134 cubic inches, composed of - - cub. in. - Oxygene 82,9 - Nitrogene 47,0 - Carbonic acid 4,1 - - -And after respiration, 125 cubic inches, consisting of - - cub. in. - Oxygene 71,5 - Nitrogene 45,6 - Carbonic acid 7,9 - -So that comparing the quantities, it appears, that 11,4 of oxygene and -1,4 of nitrogene, were consumed in this experiment, and 3,8 of carbonic -acid produced. - -I was much surprised at the small quantity of oxygene that had been -consumed in this experiment. This quantity was less than that expended -during the respiration of atmospheric air for half a minute: the -portion of carbonic acid evolved was likewise smaller. I could detect -no source of inaccuracy, and it was difficult to suppose that the -greater depth and fulness of the inspirations could make any difference. - -E. 2. I now respired at the same temperature, after a full expiration, -162 cubic inches of gas, composed of 133 oxygene and 20 nitrogene for -two minutes, imitating as much as possible, the natural respiration. -After the experiment, they filled a space equal to 123 cubic inches. -And when the analysis and calculations had been made as in the last -experiment, it appeared that 57 cubic inches of oxygene, and 2 of -nitrogene had been absorbed, whilst 21 cubic inches of carbonic acid -had been formed. - -Now from the estimations in the last section, it appears that 63 cubic -inches of oxygene are consumed, and about 52 cubic inches of carbonic -acid produced every two minutes during the natural respiration of -common air. So that supposing the experiment accurate, 6 cubic inches -of oxygene less are absorbed, and 30 cubic inches less of carbonic acid -produced every minute, when oxygene nearly pure is respired, than when -atmospheric air is respired. - -Both these experiments were made in the morning, at a time when I was -in perfect health; so that there could be apparently no source of error -from accidental circumstances. - -The uncommon and unexpected nature of the results, made me however, -very sceptical concerning them; and before I would draw any inferences, -I resolved to ascertain the comparative consumption of atmospheric air -and oxygene by the smaller quadrupeds, for which purpose, I made the -following experiment. - -E. 3. Of two strong and healthy small mice, apparently of the same -breed, and exactly similar. - -One was introduced into a jar containing 10 cubic inches and half of -oxygene, and 3 cubic inches of nitrogene, and made to rest on a bit of -cheese. - -The other was introduced into a jar containing fifteen cubic inches and -half of atmospheric air, and made to rest in the same manner on cheese. - -The mouse in oxygene began apparently to suffer in about half an hour, -and occasionally panted very much; in about an hour he lay down on his -side as if dying. The jars were often agitated, that the gases might be -well mingled. - -The mouse in atmospheric air became very feeble in 40 minutes, and at -the end of 50 minutes was taken out through the mercury alive, but -unable to stand. - -The mouse in oxygene was taken out in the same manner after an hour and -quarter, alive, but motionless, and breathing very deeply. - -The gas in the jars was examined. That in the oxygene jar filled a -space exactly equal to 12,7 cubic inches, and analised, was found to -consist of 1,7 carbonic acid, 2,6 of nitrogene, and 8,4 of oxygene. So -that absolutely, 2,1 cubic inches of oxygene and,4 of nitrogene had -been consumed, and 1,7 of carbonic acid produced. - -The gas in the atmospheric air jar was diminished nearly to 14,4, and -consisted of 2,1 carbonic acid, 1,4 oxygene; and 10,9 nitrogene. So -that 2,7 of oxygene and,5 of nitrogene, had been consumed by the mouse; -and 2,1 of carbonic acid produced. - -Hence it appears, that the mouse in atmospheric air consumed nearly -one third more oxygene and produced nearly one fourth more carbonic -acid in respiration in 55 minutes, than the other in an hour and -quarter in oxygene. And if we consider the perpetual diminution of the -oxygene of the atmospheric air; from which at last it became almost -incapable of supporting the life of the animal; we may conclude, that -the quantity of oxygene consumed by it, had the air been perpetually -renovated, would have been much more considerable. - -I design very shortly, to repeat these experiments, and to make others -on the comparative consumption of oxygene and atmospheric air, by the -larger quadrupeds. Whatever may be the results, I hope to be able to -ascertain from them, why pure oxygene is incapable of supporting life. - - -VIII. _Observations on the changes effected in the blood, by -atmospheric air and oxygene._ - -From the experiments of Mr. Cigna and Dr. Priestley,[202] it appears -that the coagulum of the venous blood becomes florid at its surface -when exposed to the atmosphere, though covered and defended from the -immediate contact of air by a very thick stratum of serum. - -[202] Dr. Priestley found that it likewise became florid at the surface -when covered by milk; but that it underwent little or no alteration of -color under water and most other fluids.—Vol. 3. p. 372. - -Hence it is evident, that serum is capable of dissolving either the -whole compound atmospheric air, or the oxygene of it. - -Supposing what indeed is most probable from numerous analogies, that -it dissolves the whole compound; it would follow, that the coloring -of the coagulum of blood under serum, depended upon the decomposition -of the atmospheric air condensed in the serum, the oxygene[203] of it -combining with the red particles, and the nitrogene either remaining -dissolved in the fluid, or being liberated through it into the -atmosphere. - -Now the circulating blood consists of red particles, floating in and -diffused through serum and coagulable lymph. - -[203] There are many analogous decompositions. Dr. Priestley noticed -(and I have often made the observation) that green oxide of iron, or -the precipitate from pale green sulphate of iron by caustic alkali, -became red at the surface, when covered by a thick stratum of water. In -my experiments on the green muriate and sulphate of iron, I observed -that part of some dark oxide of iron which was at the bottom of a -trough of water 9 inches deep, became red at the surface nearly in the -same time as another portion of the same precipitation that was exposed -to the atmosphere. This oxygenation must depend upon the decomposition -of atmospheric air constantly dissolved by the water. - -In natural respiration, the red particles are rendered of a brighter -tinge during the passage of the blood through the pulmonary veins. And -as we have seen in the last sections, during respiration atmospheric -air is decomposed; all the oxygene of it consumed, _apparently_ a small -portion of the nitrogene lost, and a considerable quantity of carbonic -acid produced. - -It seems therefore reasonable to suppose, that the whole compound -atmospheric air passing through the moist coats of the vessels is first -dissolved by the serum of the venous blood, and in its condensed state, -decomposed by the affinity of the red particles for its oxygene; the -greater part of the nitrogene being liberated unaltered; but a minute -portion of it possibly remaining condensed in the serum and coagulable -lymph, and passing with them into the left chamber of the heart. - -From the experiments on the respiration of nitrous oxide and hydrogene, -it appears that a certain portion of the carbonic acid produced in -respiration, is evolved from the venous blood; but as a much greater -quantity is generated during the respiration of common air and oxygene, -than during that of hydrogene in equal times, it is not impossible but -that some portion of it may be formed by the combination of charcoal in -the red particles with the oxygene dissolved in the serum; but this can -only be determined by farther experiments. - -Supposing that no part of the water evolved in solution by the expired -gas of common air is formed immediately in respiration, it will follow -that a very considerable quantity of oxygene must be constantly -_combined_ with the red particles, even allowing the consumption of -a certain portion of it to form carbonic acid; for the carbonic acid -evolved, rarely amounts to more than three fourths of the volume of the -oxygene consumed. - -Perhaps the serum of the blood is capable of dissolving a larger -quantity of atmospheric air than of pure oxygene. On this supposition, -it would be easy to explain the smaller consumption of oxygene in the -experiments in the last section. - - -IX. _Observations on the respiration of Nitrous Oxide._ - -The experiments in the first Division of this Research, prove that -nitrous oxide when respired by animals, produces peculiar changes in -their blood and in their organs, first connected with increased living -action; but terminating in death. - -From the experiments in this Division, it appears, that nitrous oxide -is rapidly absorbed by the circulating venous blood, and of course its -condensed oxygene and nitrogene distributed in the blood over the whole -of the system. - -Concerning the changes effected in the principles of the impregnated -blood during circulation and its action upon the nervous and muscular -fibre; it is useless to reason in the present state of our knowledge. - -It would be easy to form theories referring the action of blood -impregnated with nitrous oxide, to its power of supplying the nervous -and muscular fibre with such proportions of condensed nitrogene, -oxygene and light or etherial fluid, as enabled them more rapidly -to pass through those changes which constitute their life: but such -theories would be only collections of terms derived from known -phænomena and applied by loose analogies of language to unknown things. - -We are unacquainted with the composition of dead organised matter; and -new instruments of experiment and new modes of research must be found, -before we can ascertain even our capabilities of discovering the laws -of life. - - - - -RESEARCH IV. - -RELATING TO THE EFFECTS PRODUCED BY THE RESPIRATION OF NITROUS OXIDE. - - -DIVISION I. - - _HISTORY of the DISCOVERY.—Effects produced by the - RESPIRATION of different GASES._ - -A short time after I began the study of Chemistry, in March 1798, -my attention was directed to the dephlogisticated nitrous gas of -Priestley, by Dr. Mitchill’s Theory of Contagion.[204] - -[204] Dr. Mitchill attempted to prove from some phænomena connected -with contagious diseases, that dephlogisticated nitrous gas which he -called oxide of septon, was the principle of contagion, and capable of -producing the most terrible effects when respired by animals in the -minutest quantities or even when applied to the skin or muscular fibre. - -The fallacy of this Theory was soon demonstrated, by a few coarse -experiments made on small quantities of the gas procured from zinc and -diluted nitrous acid. Wounds were exposed to its action, the bodies of -animals were immersed in it without injury; and I breathed it mingled -in small quantities with common air, without remarkable effects. An -inability to procure it in sufficient quantities, prevented me at -this time, from pursuing the experiments to any greater extent. I -communicated an account of them to Dr. Beddoes. - -In 1799, my situation in the Medical Pneumatic Institution, made it my -duty to investigate the physiological effects of the aëriform fluids, -the properties of which presented a chance of useful agency. At this -period I recommenced the investigation. - -A considerable time elapsed before I was able to procure the gas in a -state of purity, and my first experiments were made on the mixtures of -nitrous oxide, nitrogene and nitrous gas, which are produced during -metallic solutions. - -In the beginning of March, I prepared a large quantity of impure -nitrous oxide from the nitrous solution of zinc. Of this I often -breathed the quantities of a quart and two quarts generally mingled -with more than equal parts of oxygene or common air. In the most -decisive of those trials, its effects appeared to be depressing, and -I imagined that it produced a tendency to fainting: the pulse was -certainly rendered slower under its operation. - -At this time, Mr. Southey respired it in an highly diluted state; it -occasioned a slight degree of giddiness, and considerably diminished -the quickness of his pulse. - -Mr. C. Coates likewise respired it highly diluted, with similar effects. - -In April, I obtained nitrous oxide in a state of purity, and -ascertained many of its chemical properties. Reflections upon these -properties and upon the former trials, made me resolve to endeavour -to inspire it in its pure form, for I saw no other way in which its -respirability, or powers could be determined.[205] - -[205] I did not attempt to experiment upon animals, because they die -nearly in equal times in non-respirable gases, and gases incapable of -supporting life and possessed of no action on the venous blood. - -I was aware of the danger of this experiment. It certainly would never -have been made if the hypothesis of Dr. Mitchill had in the least -influenced my mind. I thought that the effects might be possibly -depressing and painful, but there were many reasons which induced me -to believe that a single inspiration of a gas apparently possessing -no immediate action on the irritable fibre, could neither destroy or -materially injure the powers of life. - -On April 11th, I made the first inspiration of pure nitrous oxide; -it passed through the bronchia without stimulating the glottis, and -produced no uneasy feeling in the lungs. - -The result of this experiment, proved that the gas was respirable, and -induced me to believe that a farther trial of its effects might be made -without danger. - -On April 16th, Dr. Kinglake being accidentally present, I breathed -three quarts of nitrous oxide from and into a silk bag for more than -half a minute, without previously closing my nose or exhausting my -lungs. - -The first inspirations occasioned a slight degree of giddiness. This -was succeeded by an uncommon sense of fulness of the head, accompanied -with loss of distinct sensation and voluntary power, a feeling -analogous to that produced in the first stage of intoxication; but -unattended by pleasurable sensation. Dr. Kinglake, who felt my pulse, -informed me that it was rendered quicker and fuller. - -This trial did not satisfy me with regard to its powers; comparing it -with the former ones I was unable to determine whether the operation -was stimulant or depressing. - -I communicated the result to Dr. Beddoes, and on April the 17th, he was -present, when the following experiment was made. - -Having previously closed my nostrils and exhausted my lungs, I breathed -four quarts of nitrous oxide from and into a silk bag. The first -feelings were similar to those produced in the last experiment; but -in less than half a minute, the respiration being continued, they -diminished gradually, and were succeeded by a sensation analogous to -gentle pressure on all the muscles, attended by an highly pleasurable -thrilling, particularly in the chest and the extremities. The objects -around me became dazzling and my hearing more acute. Towards the last -inspirations, the thrilling increased, the sense of muscular power -became greater, and at last an irresistible propensity to action was -indulged in; I recollect but indistinctly what followed; I know that my -motions were various and violent. - -These effects very soon ceased after respiration. In ten minutes, I had -recovered my natural state of mind. The thrilling in the extremities, -continued longer than the other sensations.[206] - -This experiment was made in the morning; no languor or exhaustion was -consequent, my feelings throughout the day were as usual, and I passed -the night in undisturbed repose. - -[206] Dr. Beddoes has given some account of this experiment, in his -Notice of some observations made at the Medical Pneumatic Institution. -It was noticed in Mr. Nicholson’s Phil. Journal for May 1799. - -The next morning the recollections of the effects of the gas were -very indistinct, and had not remarks written immediately after the -experiment recalled them to my mind, I should have even doubted of -their reality. I was willing indeed to attribute some of the strong -emotion to the enthusiasm, which I supposed must have been necessarily -connected with the perception of agreeable feelings, when I was -prepared to experience painful sensations. Two experiments however, -made in the course of this day, with sceptism, convinced me that the -effects were solely owing to the specific operation of the gas. - -In each of them I breathed five quarts of nitrous oxide for rather a -longer time than before. The sensations produced were similar, perhaps -not quite so pleasurable; the muscular motions were much less violent. - -Having thus ascertained the powers of the gas, I made many experiments -to ascertain the length of time for which it might be breathed with -safety, its effects on the pulse, and its general effects on the health -when often respired. - -I found that I could breathe nine quarts of nitrous oxide for three -minutes, and twelve quarts for rather more than four. I could never -breathe it in any quantity, so long as five minutes. Whenever its -operation was carried to the highest extent, the pleasurable thrilling -at its height about the middle of the experiment, gradually diminished, -the sense of pressure on the muscles was lost; impressions ceased to be -perceived; vivid ideas passed rapidly through the mind, and voluntary -power was altogether destroyed, so that the mouth-piece generally dropt -from my unclosed lips. - -Whenever the gas was in a high state of purity, it tasted distinctly -sweet to the tongue and palate, and had an agreeable odor. I often -thought that it produced a feeling somewhat analogous to taste, in -its application to my lungs. In one or two experiments, I perceived a -distinct sense of warmth in my chest. - -I never felt from it any thing like oppressive respiration: my -inspirations became deep in proportion as I breathed it longer; -but this phænomenon arose from increased energy of the muscles of -respiration, and from a desire of increasing the pleasurable feelings. - -Generally when I breathed from six to seven quarts, muscular motions -were produced to a certain extent; sometimes I manifested my pleasure -by stamping or laughing only; at other times, by dancing round the room -and vociferating. - -After the respiration of small doses, the exhilaration generally lasted -for five or six minutes only. In one or two experiments when ten quarts -had been breathed for near four minutes, an exhilaration and a sense of -slight intoxication lasted for two or three hours. - -On May 3d. To ascertain whether the gas would accelerate or retard -the progress of sleep, I breathed at about 8 o’clock in the evening, -25 quarts of nitrous oxide, in quantities of six at a time, allowing -but short intervals between each dose. The feelings were much less -pleasurable than usual, and during the consumption of the two last -doses, almost indifferent; indeed the gas was breathed rather too soon -after its production and contained some suspended acid vapour which -stimulated the lungs so as to induce coughing. - -After the experiments, for the first time I was somewhat depressed and -debilitated; my propensity to sleep however, came on at the usual hour, -and as usual was indulged in, my repose was sound and unbroken. - -Between May and July, I habitually breathed the gas, occasionally three -or four times a day for a week together; at other periods, four or five -times a week only. - -The doses were generally from six to nine quarts; their effects -appeared undiminished by habit, and were hardly ever exactly similar. -Sometimes I had the feelings of intense intoxication, attended with but -little pleasure; at other times, sublime emotions connected with highly -vivid ideas; my pulse was generally increased in fulness, but rarely in -velocity. - -The general effects of its operation upon my health and state of mind, -are extremely difficult of description; nor can I well discriminate -between its agency and that of other physical and moral causes. - -I slept much less than usual, and previous to sleep, my mind was long -occupied by visible imagery. I had a constant desire of action, a -restlessness, and an uneasy feeling about the præcordia analogous to -the sickness of hope. - -But perhaps these phænomena in some measure depended on the interest -and labour connected with the experimental investigation relating -to the production of nitrous oxide, by which I was at this time -incessantly occupied. - -My appetite was as usual, and my pulse not materially altered. -Sometimes for an hour after the inspiration of the gas, I experienced -a species of mental indolence[207] pleasing rather than otherwise, and -never ending in listlessness. - -[207] Mild physical pleasure is perhaps always destructive to action. -Almost all our powerful voluntary actions, arise either from hope, -fear, or desire; and the most powerful from desire, which is an emotion -produced by the coalescence of hope or ideal pleasure with physical -pain. - -During the last week in which I breathed it uniformly, I imagined that -I had increased sensibility of touch: my fingers were pained by any -thing rough, and the tooth edge produced from slighter causes than -usual. I was certainly more irritable, and felt more acutely from -trifling circumstances. My bodily strength was rather diminished than -increased. - -At the end of July, I left off my habitual course of respiration; -but I continued occasionally to breathe the gas, either for the sake -of enjoyment, or with a view of ascertaining its operation under -particular circumstances. - -In one instance, when I had head-ache from indigestion, it was -immediately removed by the effects of a large dose of gas; though it -afterwards returned, but with much less violence. In a second instance, -a slighter degree of head-ache was wholly removed by two doses of gas. - -The power of the immediate operation of the gas in removing intense -physical pain, I had a very good opportunity of ascertaining. - -In cutting one of the unlucky teeth called dentes sapientiæ, I -experienced an extensive inflammation of the gum, accompanied with -great pain, which equally destroyed the power of repose, and of -consistent action. - -On the day when the inflammation was most troublesome, I breathed -three large doses of nitrous oxide. The pain always diminished after -the first four or five inspirations; the thrilling came on as usual, -and uneasiness was for a few minutes, swallowed up in pleasure. As the -former state of mind however returned, the state of organ returned -with it; and I once imagined that the pain was more severe after the -experiment than before. - -In August, I made many experiments with a view of ascertaining whether -any analogy existed between the sensible effects of the different gases -which are sooner or later fatal to life when respired, and those of -nitrous oxide. - -I respired four quarts of Hydrogene[208] nearly pure produced from -zinc and muriatic acid, for near a minute, my lungs being previously -exhausted and my nostrils carefully closed. The first six or seven -inspirations produced no sensations whatever; in half a minute, I -perceived a disagreeable oppression of the chest, which obliged me to -respire very quickly; this oppression gradually increased, till at last -the pain of suffocation compelled me to leave off breathing. I felt no -giddiness during or after the experiment; my pulse was rendered feebler -and quicker; and a by-stander informed me that towards the last, my -cheeks became purple. - -[208] Pure hydrogene has been often respired by different Philosophers, -particularly by Scheele, Fontana, and the adventurous and unfortunate -Rosier. - -In a second experiment, when the hydrogene was procured from iron and -diluted sulphuric acid, I was unable to respire it for so long as three -quarters of a minute; a transient giddiness and muscular debility -were produced, the pulse was rendered very feeble, and the pain of -suffocation was greater than before. - -I breathed three quarts of Nitrogene mingled with a very small portion -of carbonic acid, for near a minute. It produced no alteration in -my sensations for the first twenty seconds; then the painful sense -of suffocation gradually came on, and increased rapidly in the -last quarter of the minute, so as to oblige me to desist from the -experiment. My pulse was rendered feebler and quicker. I felt no -affection whatever in the head. - -Mr. Watt’s observations on the respiration of diluted Hydrocarbonate -by men, and Dr. Beddoes’s experiments on the destruction of animals by -pure hydrocarbonate, proved that its effects were highly deleterious. - -As it destroyed life apparently by rendering the muscular fibre -inirritable without producing any previous excitement, I was anxious -to compare its sensible effects with those of nitrous oxide, which at -this time I believed to destroy life by producing the highest possible -excitement, ending in læsion of organisation. - -In the first experiment, I breathed for near a minute, three quarts of -hydrocarbonate mingled with nearly two quarts of atmospheric air.[209] -It produced a slight giddiness and pain in the head, and a momentary -loss of voluntary power: my pulse was rendered much quicker and -feebler. These effects however, went off in five minutes, and I had no -return of giddiness. - -[209] I believe it had never been breathed before by any individual, in -a state so little diluted. - -Emboldened by this trial, in which the feelings were not unlike those -I experienced in the first experiments on nitrous oxide, I resolved to -breathe pure hydrocarbonate. - -For this purpose, I introduced into a silk bag, four quarts of gas -nearly pure, which was carefully produced from the decomposition of -water by charcoal an hour before, and which had a very strong and -disagreeable smell. - -My friend, Mr. James Tobin, Junr. being present, after a forced -exhaustion of my lungs, the nose being accurately closed, I made -three inspirations and expirations of the hydrocarbonate. The first -inspiration produced a sort of numbness and loss of feeling in the -chest and about the pectoral muscles. After the second inspiration, -I lost all power of perceiving external things, and had no distinct -sensation except a terrible oppression on the chest. During the -third expiration, this feeling disappeared, I seemed sinking into -annihilation, and had just power enough to drop the mouth-piece from -my unclosed lips. A short interval must have passed during which I -respired common air, before the objects about me were distinguishable. -On recollecting myself, I faintly articulated, “_I do not think I shall -die_.” Putting my finger on the wrist, I found my pulse thread-like and -beating with excessive quickness. - -In less than a minute, I was able to walk, and the painful oppression -on the chest directed me to the open air. - -After making a few steps which carried me to the garden, my head -became giddy, my knees trembled, and I had just sufficient voluntary -power to throw myself on the grass. Here the painful feeling of the -chest increased with such violence as to threaten suffocation. At -this moment, I asked for some nitrous oxide. Mr. Dwyer brought me a -mixture of oxygene and nitrous oxide. I breathed this for a minute, -and _believed_ myself relieved. In five minutes, the painful feelings -began gradually to diminish. In an hour they had nearly disappeared, -and I felt only excessive weakness and a slight swimming of the head. -My voice was very feeble and indistinct. This was at two o’clock in the -afternoon. - -I afterwards walked slowly for about half an hour, with Mr. Tobin, -Junr. and on my return, was so much stronger and better, as to believe -that the effects of the gas had disappeared; though my pulse was 120 -and very feeble. I continued without pain for near three quarters of -an hour; when the giddiness returned with such violence as to oblige -me to lie on the bed; it was accompanied with nausea, loss of memory, -and deficient sensation. In about an hour and half, the giddiness went -off, and was succeeded by an excruciating pain in the forehead and -between the eyes, with transient pains in the chest and extremities. -Towards night these affections gradually diminished. At ten,[210] no -disagreeable feeling except weakness remained. I slept sound, and -awoke in the morning very feeble and very hungry. No recurrence of the -symptoms took place, and I had nearly recovered my strength by the -evening. - -I have been minute in the account of this experiment because it -proves, that hydrocarbonate acts as a sedative, i. e. that it -produces diminution of vital action, and debility, without previously -exciting. There is every reason to believe, that if I had taken four -or five inspirations instead of three, they would have destroyed life -immediately without producing any painful sensation. Perhaps most of -the uneasy feelings after the experiment, were connected with the -return of the healthy condition of organs.[211] - -[210] I ought to observe, that between eight and ten, I took by the -advice of Dr. Beddoes, two or three doses of diluted nitric acid. - -[211] By whatever cause the exhaustion of organs is produced, pain -is almost uniformly connected with their returning health. Pain is -rarely ever perceived in limbs debilitated by fatigue till after they -have been for some hours at rest. Pain is uniformly connected with the -recovery from the debility induced by typhus, often with the recovery -from that produced by the stimulation of opium and alcohol. - -About a week after this experiment, I attempted to respire Carbonic -acid, not being at the time acquainted with the experiments of Rosier. - -I introduced into a silk bag four quarts of well washed carbonic acid -produced from carbonate of ammoniac[212] by heat, and after a compleat -voluntary exhaustion of my lungs, attempted to inspire it. It tasted -strongly acid in the mouth and fauces, and produced a sense of burning -at the top of the uvula. In vain I made powerful voluntary efforts -to draw it into the windpipe; at the moment that the epiglottis was -raised a little, a painful stimulation was induced, so as to close -it spasmodically on the glottis; and thus in repeated trials I was -prevented from taking a single particle of carbonic acid into my lungs. - -[212] Carbonic acid is produced in this way in a high state of purity, -and with great readiness. - -I tried to breathe a mixture of two quarts of common air and three of -carbonic acid, without success; it stimulated the epiglottis nearly in -the same manner as pure carbonic acid, and was perfectly non-respirable. - -I found that a mixture of three quarts of carbonic acid with seven of -common air was respirable, I breathed it for near a minute. At the -time, it produced a slight degree of giddiness, and an inclination to -sleep. These effects however, very rapidly disappeared after I had -ceased to breathe,[213] and no other affections followed. - -[213] Carbonic acid possesses no action on arterial blood. Hence -perhaps, its slight effects when breathed mingled with large quantities -of common air. Its effects are very marked upon venous blood! If -it were thrown forcibly into the lungs of animals, the momentary -application of it to the pulmonary venous blood would probably destroy -life. - -During the course of experiments on nitrous oxide, I several times -breathed Oxygene procured from manganese by heat, for from three to -five minutes. - -In respiring eight or ten quarts; for the first two or three minutes -I could perceive no effects. Towards the end, even when I breathed -very slowly, my respiration became oppressed, and I felt a sensation -analogous to that produced by the want of fresh air; though but little -of the oxygene had been consumed. - -In one experiment when I breathed from and into a bag containing 20 -quarts of oxygene for near six minutes; Dr. Kinglake felt my pulse, -and found it not altered in velocity, but rather harder than before. I -perceived no effects but those of oppression on the chest[214]. - -[214] In a conversation with Mr. Watt, relating to the powers of gases, -that excellent philosopher told me he had for some time entertained -a suspicion, that the effects attributed to oxygene produced from -manganese by heat, in some measure depended upon nitrous acid suspended -in the gas, formed during ignition by the union of some of the oxygene -of the manganese with nitrogene likewise condensed in it. - -In the course of experiments on nitrous acid, detailed in Research -I. made in September, October, and December, 1799, I several times -experienced a severe oppression on the chest and difficulty of -respiration, not unanalogous to that produced by oxygene, but much more -violent, from breathing an atmosphere loaded with nitrous acid vapour. -This fact seemed to confirm Mr. Watt’s suspicion. I confess, however, -that I have never been able to detect any smell of nitrous acid, either -by means of my own organs or those of others, during the production -of oxygene; when the gas is suffered to pass into the atmosphere. The -oxygene breathed in the experiments detailed in the text, had been for -some days in contact with water. - -Having observed in my experiments upon venous blood, that Nitrous gas -rendered that fluid of a purple tinge, very like the color generated -in it by nitrous oxide; and finding no painful effects produced by -the application of nitrous gas to the bare muscular fibre, I began to -imagine that this gas might be breathed with impunity, provided it were -possible in any way to free the lungs of common air before inspiration, -so as to prevent the formation of nitrous acid. - -On this supposition, during a fit of enthusiasm produced by the -respiration of nitrous oxide, I resolved to endeavour to breathe -Nitrous gas. - -114 cubic inches of nitrous gas were introduced into the large -mercurial airholder; two small silk bags of the capacity of seven -quarts were filled with nitrous oxide. - -After a forced exhaustion of my lungs, my nose being accurately closed, -I made three inspirations and expirations of nitrous oxide in one -of the bags, to free my lungs as much as possible from atmospheric -oxygene; then, after a full expiration of the nitrous oxide, I -transferred my mouth from the mouth-piece of the bag to that of the -airholder, and turning the stop-cock, attempted to inspire the nitrous -gas.—In passing through my mouth and fauces, it tasted astringent and -highly disagreeable; it occasioned a sense of burning in the throat, -and produced a spasm of the epiglottis so painful as to oblige me to -desist instantly from attempts to inspire it. After moving my lips from -the mouth-piece, when I opened them to inspire common air, aëriform -nitrous acid was instantly formed in my mouth, which burnt the tongue -and palate, injured the teeth, and produced an inflammation of the -mucous membrane which lasted for some hours. - -As after the respiration of nitrous oxide in the experiments in the -last Research, a small portion of the residual atmospheric air remained -in the lungs, mingled with the gas, after forced expiration; it is -most probable that a minute portion of nitrous acid was formed in this -experiment, when the nitrous gas was taken into the mouth and fauces, -which might produce its stimulating properties. If so, perhaps I owe my -life to the circumstance; for supposing I had taken an inspiration of -nitrous gas, and even that it had produced no positive effects, it is -highly improbable, that by breathing nitrous oxide, I should have freed -my lungs from it, so as to have prevented the formation of nitrous acid -when I again inspired common air. I never design again to attempt so -rash an experiment. - -In the beginning of September I often respired nitrous oxide mingled -with different proportions of common air or oxygene. The effects -produced by the diluted gas were much less violent than those produced -by pure nitrous oxide. They were generally pleasant: the thrilling was -not often perceived, but a sense of exhilaration was almost constant. - -Between September and the end of October, I made but few experiments -on respiration, almost the whole of my time being devoted to chemical -experiments on the production and analysis of nitrous oxide. - -At this period my health being somewhat injured by the constant labour -of experimenting, and the perpetual inhalation of the acid vapours of -the laboratory, I went into Cornwall; where new associations of ideas -and feelings, common exercise, a pure atmosphere, luxurious diet and -moderate indulgence in wine, in a month restored me to health and vigor. - -Nov. 27th. Immediately after my return, being fatigued by a long -journey, I respired nine quarts of nitrous oxide, having been precisely -thirty-three days without breathing any. The feelings were different -from those I had experienced in former experiments. After the first -six or seven inspirations, I gradually began to lose the perception -of external things, and a vivid and intense recollection of some -former experiments passed through my mind, so that I called out “_what -an amazing concatenation of ideas!_” I had no pleasurable feeling -whatever, I used no muscular motion, nor did I feel any disposition -to it; after a minute, when I made the note of the experiment, all -the uncommon sensations had vanished; they were succeeded by a slight -soreness in one of the arms and in the leg: in three minutes these -affections likewise disappeared. - -From this experiment I was inclined to suppose that my newly acquired -health had diminished my susceptibility to the effects of the gas. -About ten days after, however, I had an opportunity of proving the -fallacy of this supposition. - -Immediately after a journey of 126 miles, in which I had no sleep the -preceding night, being much exhausted, I respired seven quarts of gas -for near three minutes. It produced the usual pleasurable effects, -and slight muscular motion. I continued exhilarated for some minutes -afterwards: but in half an hour found myself neither more or less -exhausted than before the experiment. I had a great propensity to sleep. - -I repeated the experiment four or five times in the following week, -with similar effects. My susceptibility was certainly not diminished. I -even thought that I was more affected than formerly by equal doses. - -Though, except in one instance, when indeed the gas was impure, I had -experienced no decisive exhaustion after the excitement from nitrous -oxide, yet still I was far from being satisfied that it was unanalogous -to stimulants in general.—No experiment had been made in which the -excitement from nitrous oxide had been kept up for so great a length of -time and carried to so great an extent as that in which it is uniformly -succeeded by excessive debility under the agency of other powers. - -It occurred to me, that supposing nitrous oxide to be a stimulant -of the common class, it would follow that the debility produced in -consequence of excessive stimulation by a known agent, ought to be -_increased_ after excitement from nitrous oxide.[215] - -[215] In the same manner as the debility from intoxication by two -bottles of wine is increased by a third. - -To ascertain whether this was the case, I made on December 23d, at -four P. M. the following experiment. I drank a bottle of wine in -large draughts in less than eight minutes. Whilst I was drinking, -I perceived a sense of fulness in the head, and throbbing of the -arteries, not unanalogous to that produced in the first stage of -nitrous oxide excitement. After I had finished the bottle, this fulness -increased, the objects around me became dazzling, the power of distinct -articulation was lost, and I was unable to walk steadily. At this -moment the sensations were rather pleasurable than otherwise, the sense -of fulness in the head soon however increased so as to become painful, -and in less than an hour I sunk into a state of insensibility.[216] - -[216] I ought to observe that my usual drink is water, that I had -been little accustomed to take wine or spirits, and had never been -compleatly intoxicated but once before in the course of my life. This -will account for the powerful effects of a single bottle of wine. In -this situation I must have remained for two hours or two hours and half. - -I was awakened by head-ache and painful nausea. The nausea continued -even after the contents of the stomach had been ejected. The pain in -the head every minute increased; I was neither feverish or thirsty; my -bodily and mental debility were excessive, and the pulse feeble and -quick. - -In this state I breathed for near a minute and half five quarts of gas, -which was brought to me by the operator for nitrous oxide; but as it -produced no sensations whatever, and apparently rather increased my -debility, I am almost convinced that it was from some accident, either -common air, or very impure nitrous oxide. - -Immediately after this trial, I respired 12 quarts of oxygene for near -four minutes. It produced no alteration in my sensations at the time; -but immediately after I imagined that I was a little exhilarated. - -The head-ache and debility still however continuing with violence, I -examined some nitrous oxide which had been prepared in the morning, and -finding it very pure, respired seven quarts of it for two minutes and -half. - -I was unconscious of head-ache after the third inspiration; the usual -pleasurable thrilling was produced, voluntary power was destroyed, and -vivid ideas rapidly passed through my mind; I made strides across the -room, and continued for some minutes much exhilarated. Immediately -after the exhilaration had disappeared, I felt a slight return of the -head-ache; it was connected with transient nausea. After two minutes, -when a small quantity of acidified wine had been thrown from the -stomach, both the nausea and head-ache disappeared; but languor and -depression not very different in degree from those existing before the -experiment, succeeded. They however, gradually went off before bed -time. I slept sound the whole of the night except for a few minutes, -during which I was kept awake by a trifling head-ache. In the morning, -I had no longer any debility. No head-ache or giddiness came on after I -had arisen, and my appetite was very great. - -This experiment proved, that debility from intoxication was not -increased by excitement from nitrous oxide. The head-ache and -depression, it is probable, would have continued longer if it had not -been administered. Is it not likely that the slight nausea following -the effects of the gas was produced by new excitability given to the -stomach? - -To ascertain with certainty, whether the most extensive action of -nitrous oxide compatible with life, was capable of producing debility, -I resolved to breathe the gas for such a time and in such quantities, -as to produce excitement equal in duration and superior in intensity to -that occasioned by high intoxication from opium or alcohol. - -To habituate myself to the excitement, and to carry it on gradually. - -On December 26th, I was inclosed in an air-tight breathing-box,[217] -of the capacity of about 9 cubic feet and half, in the presence of Dr. -Kinglake. - -After I had taken a situation in which I could by means of a curved -thermometer inserted under the arm, and a stop-watch, ascertain the -alterations in my pulse and animal heat, 20 quarts of nitrous oxide -were thrown into the box. - -For three minutes I experienced no alteration in my sensations, though -immediately after the introduction of the nitrous oxide the smell and -taste of it were very evident.[218] - -[217] The plan of this box was communicated by Mr. Watt. An account of -it will be detailed in the _Researches_. - -[218] The nitrous oxide was too diluted to act much; it was mingled -with near 32 times its bulk of atmospheric air. - -In four minutes I began to feel a slight glow in the cheeks, and a -generally diffused warmth over the chest, though the temperature of the -box was not quite 50°. I had neglected to feel my pulse before I went -in; at this time it was 104 and hard, the animal heat was 98°. In ten -minutes the animal heat was near 99°, in a quarter of an hour 99.5°, -when the pulse was 102, and fuller than before. - -At this period 20 quarts more of nitrous oxide were thrown into the -box, and well-mingled with the mass of air by agitation. - -In 25 minutes the animal heat was 100°, pulse 124. In 30 minutes, 20 -quarts more of gas were introduced. - -My sensations were now pleasant; I had a generally diffused warmth -without the slightest moisture of the skin, a sense of exhilaration -similar to that produced by a small dose of wine, and a disposition to -muscular motion and to merriment. - -In three quarters of an hour the pulse was 104, and animal heat not -99,5°, the temperature of the chamber was 64°. The pleasurable feelings -continued to increase, the pulse became fuller and slower, till in -about an hour it was 88, when the animal heat was 99°. - -20 quarts more of air were admitted. I had now a great disposition to -laugh, luminous points seemed frequently to pass before my eyes, my -hearing was certainly more acute and I felt a pleasant lightness and -power of exertion in my muscles. In a short time the symptoms became -stationary; breathing was rather oppressed, and on account of the great -desire of action, rest was painful. - -I now came out of the box, having been in precisely an hour and quarter. - -The moment after, I began to respire 20 quarts of unmingled nitrous -oxide. A thrilling extending from the chest to the extremities was -almost immediately produced. I felt a sense of tangible extension -highly pleasurable in every limb; my visible impressions were dazzling -and apparently magnified, I heard distinctly every sound in the room -of my situation.[219] By degrees as the pleasurable and was perfectly -aware sensations increased, I lost all connection with external things; -trains of vivid visible images rapidly passed through my mind and -were connected with words in such a manner, as to produce perceptions -perfectly novel. I existed in a world of newly connected and newly -modified ideas. I theorised; I imagined that I made discoveries. -When I was awakened from this semi-delirious trance by Dr. Kinglake, -who took the bag from my mouth, Indignation and pride were the first -feelings produced by the sight of the persons about me. My emotions -were enthusiastic and sublime; and for a minute I walked round the room -perfectly regardless of what was said to me. As I recovered my former -state of mind, I felt an inclination to communicate the discoveries -I had made during the experiment. I endeavoured to recall the ideas, -they were feeble and indistinct; one collection of terms, however, -presented itself: and with the most intense belief and prophetic -manner, I exclaimed to Dr. Kinglake, “_Nothing exists but thoughts!—the -universe is composed of impressions, ideas, pleasures and pains!_” - -[219] In all these experiments after the first minute, my cheeks became -purple. - -About three minutes and half only, had elapsed during this experiment, -though the time as measured by the relative vividness of the -recollected ideas, appeared to me much longer. - -Not more than half of the nitrous oxide was consumed. After a minute, -before the thrilling of the extremities had disappeared, I breathed -the remainder. Similar sensations were again produced; I was quickly -thrown into the pleasurable trance, and continued in it longer than -before. For many minutes after the experiment, I experienced the -thrilling in the extremities, the exhilaration continued nearly two -hours. For a much longer time I experienced the mild enjoyment before -described connected with indolence; no depression or feebleness -followed. I ate my dinner with great appetite and found myself lively -and disposed to action immediately after. I passed the evening in -executing experiments. At night I found myself unusually cheerful and -active; and the hours between eleven and two, were spent in copying -the foregoing detail from the common-place book and in arranging the -experiments. In bed I enjoyed profound repose. When I awoke in the -morning, it was with consciousness of pleasurable existence, and this -consciousness more or less, continued through the day. - -Since December, I have very often breathed nitrous oxide. My -susceptibility to its power is rather increased than diminished. I -find six quarts a full dose, and I am rarely able to respire it in any -quantity for more than two minutes and half. - -The mode of its operation is somewhat altered. It is indeed very -different at different times. - -I am scarcely ever excited into violent muscular action, the emotions -are generally much less intense and sublime than in the former -experiments, and not often connected with thrilling in the extremities. - -When troubled with indigestion, I have been two or three times -unpleasantly affected after the excitement of the gas. Cardialgia, -eructations and unpleasant fulness of the head were produced. - -I have often felt very great pleasure when breathing it alone, in -darkness and silence, occupied only by ideal existence. In two or three -instances when I have breathed it amidst noise, the sense of hearing -has been painfully affected even by moderate intensity of sound. The -light of the sun has sometimes been disagreeably dazzling. I have once -or twice felt an uneasy sense of tension in the cheeks and transient -pains in the teeth. - -Whenever I have breathed the gas after excitement from moral or -physical causes, the delight has been often intense and sublime. - -On May 5th, at night, after walking for an hour amidst the scenery of -the Avon, at this period rendered exquisitely beautiful by bright -moonshine; my mind being in a state of agreeable feeling, I respired -six quarts of newly prepared nitrous oxide. - -The thrilling was very rapidly produced. The objects around me were -perfectly distinct, and the light of the candle not as usual dazzling. -The pleasurable sensation was at first local and perceived in the -lips and about the cheeks. It gradually however, diffused itself -over the whole body, and in the middle of the experiment was for a -moment so intense and pure as to absorb existence. At this moment, and -not before, I lost consciousness; it was however, quickly restored, -and I endeavoured to make a by-stander acquainted with the pleasure -I experienced by laughing and stamping. I had no vivid ideas. The -thrilling and the pleasurable feeling continued for many minutes; -I felt two hours afterwards, a slight recurrence of them, in the -intermediate state between sleeping and waking; and I had during -the whole of the night, vivid and agreeable dreams. I awoke in the -morning with the feeling of restless energy, or that desire of action -connected with no definite object, which I had often experienced in -the course of experiments in 1799. - -I have two or three times since respired nitrous oxide under similar -circumstances; but never with equal pleasure. - -During the last fortnight, I have breathed it very often; the effects -have been powerful and the sensations uncommon; but pleasurable only in -a slight degree. - -I ought to have observed that a desire to breathe the gas is always -awakened in me by the sight of a person breathing, or even by that of -an air-bag or an airholder. - -I have this day, June 5th, respired four large doses of gas. The -first two taken in the morning acted very powerfully; but produced -no thrilling or other pleasurable feelings. The effects of the third -breathed immediately after a hearty dinner were pleasant, but neither -intense or intoxicating. The fourth was respired at night in darkness -and silence after the occurrence of a circumstance which had produced -some anxiety. This dose affected me powerfully and pleasantly; a slight -thrilling in the extremities was produced; an exhiliration continued -for some time, and I have had but little return of uneasiness. 11 P. M. - -From the nature of the language of feeling, the preceding detail -contains many imperfections; I have endeavoured to give as accurate an -account as possible of the strange effects of nitrous oxide, by making -use of terms standing for the most similar common feelings. - -We are incapable of recollecting pleasures and pains of sense.[220] It -is impossible to reason concerning them, except by means of terms which -have been associated with them at the moment of their existence, and -which are afterwards called up amidst trains of concomitant ideas. - -[220] Physical pleasure and pain generally occur connected with a -compound impression, i. e. an organ and some object. When the idea left -by the compound impression, is called up by being linked accidentally -to some other idea or impression, no recurrence, or the slightest -possible, of the pleasure or pain in any form will take place. But when -the compound impression itself exists _without_ the physical pleasure -or pain, it will awaken ideal or intellectual pleasure or pain, i. e. -hope or fear. So that physical pleasure and pain are to hope and fear, -what impressions are to ideas. For instance, assuming no accidental -association, the child does not fear the fire before he is burnt. When -he puts his finger to the fire he feels the physical pain of burning, -which is connected with a visible compound impression, the fire and his -finger. Now when the compound idea of the fire and his finger, left -by the compound impression are called up by his mother, saying, “_You -have burnt your finger_,” nothing like fear or the pain of burning is -connected with it. But when the finger is brought near the fire, i. e. -when the compound impression again exists, the ideal pain of burning or -the passion of fear is awakened, and it becomes connected with those -very actions which removed the finger from the fire. - -When pleasures and pains are new or connected with new ideas, they can -never be intelligibly detailed unless associated during their existence -with terms standing for analogous feelings. - -I have sometimes experienced from nitrous oxide, sensations similar to -no others, and they have consequently been indescribable. This has been -likewise often the case with other persons. Of two paralytic patients -who were asked what they felt after breathing nitrous oxide, the first -answered, “_I do not know how, but very queer._” The second said, “_I -felt like the sound of a harp._” Probably in the one case, no analogous -feelings had ever occurred. In the other, the pleasurable thrillings -were similar to the sensations produced by music; and hence, they were -connected with terms formerly applied to music. - - -DIVISION II. - - _DETAILS of the EFFECTS produced by the RESPIRATION - of NITROUS OXIDE upon different INDIVIDUALS - furnished by THEMSELVES._ - - -The experiments related in the following details, were made in the -Medical Pneumatic Institution. - -Abstracts from many of them have been published by Dr. Beddoes.[221] - -[221] Notice of some Observations made at the Medical Pneumatic -Institution. - - -I. _Detail of_ MR. J. W. TOBIN. - -Having seen the remarkable effects produced on Mr. Davy, by breathing -nitrous oxide, the 18th of April; I became desirous of taking some. - -A day or two after I breathed 2 quarts of this gas, returning it back -again into the same bag, after two or three in inspirations, breathing -became difficult, and I occasionally admitted common air into my -lungs. While the respiration was continued, my sensations became more -pleasant. On taking the bag from my mouth, I staggered a little, but -felt no other effect. - -On the second time of making the experiment, I took nearly four quarts, -but still found it difficult to continue breathing long, though the air -which was left in the bag was far from being impure. - -The effects however, in this case, were more striking than in the -former. Increased muscular action was accompanied by very pleasurable -feelings, and a strong desire to continue the inspiration. On removing -the bag from my mouth, I laughed, staggered, and attempted to speak, -but stammered exceedingly, and was utterly unable to pronounce some -words. My usual state of mind, however, soon returned. - -On the 29th, I again breathed four quarts. The pleasant feelings -produced at first, urged me to continue the inspiration with great -eagerness. These feelings however, went off towards the end of the -experiment, and no other effects followed. The gas had probably been -breathed too long, as it would not support flame. I then proposed to -Mr. Davy, to inhale the air by the mouth from one bag, and to expire -it from the nose into another. This method was pursued with less than -three quarts, but the effects were so powerful as to oblige me to take -in a little common air occasionally. I soon found my nervous system -agitated by the highest sensations of pleasure, which are difficult -of description; my muscular powers were very much increased, and I -went on breathing with great vehemence, not from a difficulty of -inspiration, but from an eager avidity for more air. When the bags -were exhausted and taken from me, I continued breathing with the same -violence, then suddenly starting from the chair, and vociferating with -pleasure, I made towards those that were present, as I wished they -should participate in my feelings. I struck gently at Mr. Davy and a -stranger entering the room at the moment, I made towards him, and gave -him several blows, but more in the spirit of good humour than of anger. -I then ran through different rooms in the house, and at last returned -to the laboratory somewhat more composed; my spirits continued much -elevated for some hours after the experiment, and I felt no consequent -depression either in the evening or the day following, but slept as -soundly as usual. - -On the 5th of May, I again attempted to breathe nitrous oxide, but -it happened to contain suspended nitrous vapour which rendered it -non-respirable. - -On the 7th, I inspired 7 quarts of pure gas mingled with an equal -quantity of common air, the sensations were pleasant, and my muscular -power much increased. - -On the 8th, I inspired five quarts without any mixture of common air, -but the effects were not equal to those produced the day before; Indeed -there were reasons for supposing that the gas was impure. - -On the 18th, I breathed nearly six quarts of the pure nitrous oxide. It -is not easy to describe my sensations; they were superior to any thing -I ever before experienced. My step was firm, and all my muscular powers -increased. My senses were more alive to every surrounding impression; -I threw myself into several theatrical attitudes, and traversed the -laboratory with a quick step; my mind was elevated to a most sublime -height. It is giving but a faint idea of the feelings to say, that they -resembled those produced by a representation of an heroic scene on the -stage, or by reading a sublime passage in poetry when circumstances -contribute to awaken the finest sympathies of the soul. In a few -minutes the usual state of mind returned. I continued in good spirits -for the rest of the day, and slept soundly. - -Since the 18th of May, I have very often breathed nitrous oxide. In -the first experiments when pure, its effects were generally similar to -those just described. - -Lately I have seldom experienced vivid sensations. The pleasure -produced by it is slight and tranquil, I rarely feel sublime emotions -or increased muscular power. - - J. W. TOBIN. - _October, 1799._ - - -II. _Detail of_ MR. WM. CLAYFIELD. - -The first time that I breathed the nitrous oxide, it produced feelings -analogous to those of intoxication. I was for some time unconscious of -existence, but at no period of the experiment experienced agreeable -sensations, a momentary nausea followed it; but unconnected with -languor or head-ache. - -After this I several times respired the gas, but on account of the -fulness in the head and apparent throbbing of the arteries in the -brain,[222] always desisted to breathe before the full effects were -produced. In two experiments however, when by powerful voluntary -efforts I succeeded in breathing a large quantity of gas for some -minutes, I had highly pleasurable thrillings in the extremities, and -such increase of muscular power, as to be obliged to exert my limbs -with violence. After these experiments, no languor or depression -followed. - - WILLIAM CLAYFIELD. - -[222] In some of these experiments, hearing was rendered more acute. - - -III. _Letter from_ DR. KINGLAKE. - -In compliance with your desire, I will endeavour to give you a faithful -detail of the effects produced on my sensations by the inhalation of -nitrous oxide. - -My first inspiration of it was limited to four quarts, diluted with -an equal quantity of atmospheric air. After a few inspirations, a -sense of additional freedom and power (call it energy if you please) -agreeably pervaded the region of the lungs; this was quickly succeeded -by an almost delirious but highly pleasurable sensation in the brain, -which was soon diffused over the whole frame, imparting to the muscular -power at once an encreased disposition and tone for action; but the -mental effect of the excitement was such as to absorb in a sort of -intoxicating placidity, and delight, volition, or rather the power -of voluntary motion. These effects were in a greater or less degree -protracted during about five minutes, when the former state returned, -with the difference however of feeling more cheerful and alert, for -several hours after. - -It seemed also to have had the further effect of reviving rheumatic -irritations in the shoulder and knee-joints, which had not been -previously felt for many months. No perceptible change was induced in -the pulse either at or subsequent to the time of inhaling the gas. - -The effects produced by a second trial of its powers, were more -extensive, and concentrated on the brain. In this instance, nearly -six quarts undiluted, were accurately and fully inhaled. As on the -former occasion, it immediately proved agreeably respirable, but -before the whole quantity was quite exhausted, its agency was exerted -so strongly on the brain, as progressively to suspend the senses -of seeing, hearing, feeling, and ultimately the power of volition -itself. At this period, the pulse was much augmented both in force -and frequency; slight convulsive twitches of the muscles of the arms -were also induced; no painful sensation, nausea, or languor, however, -either preceded, accompanied, or followed this state, nor did a minute -elapse before the brain rallied, and resumed its wonted faculties, -when a sense of glowing warmth extending over the system, was speedily -succeeded by a re-instatement of the equilibrium of health. - -The more permanent effects were (as in the first experiment) an -invigorated feel of vital power, improved spirits, transient -irritations in different parts, but not so characteristically rheumatic -as in the former instance. - -Among the circumstances most worthy of regard in considering the -properties and administration of this powerful aërial agent, may be -ranked, the fact of its being (contrary to the prevailing opinion[223]) -both highly respirable, and salutary, that it impresses the brain -and system at large with a more or less strong and durable degree -of pleasurable sensation, that unlike the effect of other violently -exciting agents, no sensible exhaustion or diminution of vital power -accrues from the exertions of its stimulant property, that its most -excessive operation even, is neither permanently nor transiently -debilitating; and finally, that it fairly promises under judicious -application, to prove an extremely efficient remedy, as well in the -vast tribe of diseases originating from deficient irritability and -sensibility, as in those proceeding from morbid associations, and -modifications, of those vital principles. - -If you should deem any thing contained in this cursory narrative -capable of subserving in any degree the practical advantages likely to -result from your scientific and valuable investigation of the genuine -properties of the nitrous oxide, it is perfectly at your disposal. - - I am - Your sincere friend, - ROBERT KINGLAKE. - - _Bristol, June 14th, 1799._ - - To MR. DAVY. - -[223] Dr. Mitchill (an American Chemist) has erroneously supposed -its full admission to the lungs, in its concentrated state, to be -incompatible with animal life, and that in a more diluted form it -operates as a principal agent in the production of contagious diseases, -&c. This gratuitous position is thus unqualifiedly affirmed. “If a full -inspiration of gaseous oxyd be made, there will be a sudden extinction -of life; and this accordingly accounts for the fact related by Russel -(History of Aleppo, p. 232.) and confirmed by other observers, of many -persons falling down dead suddenly, when struck with the contagion of -the plague.” - -Vide Remarks on the Gaseous Oxyd of Azote, by Samuel Latham Mitchill, -M. D. - - -IV. _Detail of_ MR. SOUTHEY. - -In breathing the nitrous oxide, I could not distinguish between the -first feelings it occasioned and an apprehension of which I was unable -to divest myself. My first definite sensation was a dizziness, a -fulness in the head, such as to induce a fear of falling. This was -momentary. When I took the bag from my mouth, I immediately laughed. -The laugh was involuntary but highly pleasurable, accompanied by -a thrill all through me; and a tingling in my toes and fingers, a -sensation perfectly new and delightful. I felt a fulness in my chest -afterwards; and during the remainder of the day, imagined that my taste -and hearing were more than commonly quick. Certain I am that I felt -myself more than usually strong and chearful. - -In a second trial, by continuing the inhalation longer, I felt a thrill -in my teeth; and breathing still longer the third time, became so full -of strength as to be compelled to exercise my arms and feet. - -Now after an interval of some months, during which my health has been -materially impaired, the nitrous oxide produces an effect upon me -totally different. Half the quantity affects me, and its operation is -more violent; a slight laughter is first induced,[224] and a desire -to continue the inhalation, which is counteracted by fear from the -rapidity of respiration; indeed my breath becomes so short and quick, -that I have no doubt but the quantity which I formerly breathed, would -now destroy me. The sensation is not painful, neither is it in the -slightest degree pleasurable. - - ROBERT SOUTHEY. - -[224] In the former experiments, Mr. Southey generally respired six -quarts, now he is unable to consume two. - -In an experiment made since this paper was drawn up, the effect was -rather pleasurable. - - -V. _Letter from_ DR. ROGET. - -The effect of the first inspirations of the nitrous oxide was that of -making me vertiginous, and producing a tingling sensation in my hands -and feet: as these feelings increased, I seemed to lose the sense of -my own weight, and imagined I was sinking into the ground. I then -felt a drowsiness gradually steal upon me, and a disinclination to -motion; even the actions of inspiring and expiring were not performed -without effort: and it also required some attention of mind to keep -my nostrils closed with my fingers. I was gradually roused from this -torpor by a kind of delirium, which came on so rapidly that the air-bag -dropt from my hands. This sensation increased for about a minute after -I had ceased to breathe, to a much greater degree than before, and I -suddenly lost sight of all the objects around me, they being apparently -obscured by clouds, in which were many luminous points, similar to what -is often experienced on rising suddenly and stretching out the arms, -after sitting long in one position. - -I felt myself totally incapable of speaking, and for some time lost all -consciousness of where I was, or who was near me. My whole frame felt -as if violently agitated: I thought I panted violently: my heart seemed -to palpitate, and every artery to throb with violence; I felt a singing -in my ears; all the vital motions seemed to be irresistibly hurried on, -as if their equilibrium had been destroyed, and every thing was running -headlong into confusion. My ideas succeeded one another with extreme -rapidity, thoughts rushed like a torrent through my mind, as if their -velocity had been suddenly accelerated by the bursting of a barrier -which had before retained them in their natural and equable course. -This state of extreme hurry, agitation, and tumult, was but transient. -Every unnatural sensation gradually subsided; and in about a quarter of -an hour after I had ceased to breathe the gas, I was nearly in the same -state in which I had been at the commencement of the experiment. - -I cannot remember that I experienced the least pleasure from any of -these sensations. I can however, easily conceive, that by frequent -repetition I might reconcile myself to them, and possibly even receive -pleasure from the same sensations which were then unpleasant. - -I am sensible that the account I have been able to give of my feelings -is very imperfect. For however calculated their violence and novelty -were to leave a lasting impression on the memory, these circumstances -were for that very reason unfavourable to accuracy of comparison with -sensations already familiar. - -The nature of the sensations themselves, which bore greater resemblance -to a half delirious dream than to any distinct state of mind capable -of being accurately remembered, contributes very much to increase the -difficulty. And as it is above two months since I made the experiment, -many of the minuter circumstances have probably escaped me. - - I remain, - Yours, &c. - - P. ROGET. - To MR. DAVY. - - -VI. _Letter from_ MR. JAMES THOMSON. - -The first time I respired nitrous oxide, the experiment was made -under a strong impression of fear, and the quantity I breathed not -sufficient, as you informed me, to produce the usual effect. I did -not note very accurately my sensations. I remember I experienced a -slight degree of vertigo after the third or fourth inspiration; and -breathed with increased vigor, my inspirations being much deeper and -more vehement than ordinary. I was enabled the next time I made the -experiment, to attend more accurately to my sensations, and you have -the observations I made on them at the time. - -After the fourth inspiration, I experienced the same increased action -of the lungs, as in the former case. My inspirations became uncommonly -full and strong, attended with a thrilling sensation about the chest, -highly pleasurable, which increased to such a degree as to induce a -fit of involuntary laughter, which I in vain endeavoured to repress. -I felt a slight giddiness which lasted for a few moments only. My -inspirations now became more vehement and frequent; and I inhaled the -air with an avidity strongly indicative of the pleasure I received. -That peculiar thrill which I had at first experienced at the chest, now -pervaded my whole frame; and during the two or three last inspirations, -was attended with a remarkable tingling in my fingers and toes. My -feelings at this moment are not to be described: I felt a high, an -extraordinary degree of pleasure, different from that produced -by wine, being divested of all its gross accompaniments, and yet -approaching nearer to it than to any other sensation I am acquainted -with. - -I am certain that my muscular strength was for a time much increased. -My disposition to exert it was such as I could not repress, and the -satisfaction I felt in any violent exertion of my legs and arms is -hardly to be conceived. These vivid sensations were not of long -duration; they diminished insensibly, and in little more than a quarter -of an hour I could perceive no difference between the state I was then -in, and that previous to the respiration of the air. - -The observations I made on repeating the experiment, do not differ from -the preceding, except in the circumstance of the involuntary laughter, -which I never afterwards experienced, though I breathed the air several -times; and in the following curious fact, which, as it was dependent on -circumstances, did not always occur. - -Having respired the same quantity of air as usual, and with precisely -the same effects, I was surprised to find myself affected a few minutes -afterwards with the recurrence of a pain in my back and knees, which I -had experienced the preceding day from fatigue in walking. I was rather -inclined to deem this an accidental coincidence than an effect of the -air; but the same thing constantly occurring whenever I breathed the -air, shortly after suffering pain either from fatigue, or any other -accidental cause, left no doubt on my mind as to the accuracy of the -observation. - -I have now given you the substance of the notes I made whilst the -impressions were strong on my mind. I cannot add any thing from -recollection that will at all add to the accuracy of this account, -or assist those who have not respired this air, in forming a clearer -idea of its extraordinary effects. It is extremely difficult to convey -to others by means of words, any idea of particular sensations, of -which they have had no experience. It can only be done by making use -of such terms as are expressive of sensations that resemble them, -and in these our vocabulary is very defective. To be able at all to -comprehend the effects of nitrous oxide, it is necessary to respire it, -and after that, we must either invent new terms to express these new -and particular sensations, or attach new ideas to old ones, before we -can communicate intelligibly with each other on the operation of this -extraordinary gas. - - I am &c. - JAMES THOMSON. - _London, Sept. 21, 1799._ - - To MR. DAVY. - - -VII. _Detail of_ MR. COLERIDGE. - -The first time I inspired the nitrous oxide, I felt an highly -pleasurable sensation of warmth over my whole frame, resembling that -which I remember once to have experienced after returning from a walk -in the snow into a warm room. The only motion which I felt inclined to -make, was that of laughing at those who were looking at me. My eyes -felt distended, and towards the last, my heart beat as if it were -leaping up and down. On removing the mouth-piece the whole sensation -went off almost instantly. - -The second time, I felt the same pleasurable sensation of warmth, but -not I think, in quite so great a degree. I wished to know what effect -it would have on my impressions; I fixed my eye on some trees in the -distance, but I did not find any other effect except that they became -dimmer and dimmer, and looked at last as if I had seen them through -tears. My heart beat more violently than the first time. This was after -a hearty dinner. - -The third time I was more violently acted on than in the two former. -Towards the last, I could not avoid, nor indeed felt any wish to avoid, -beating the ground with my feet; and after the mouth-piece was removed, -I remained for a few seconds motionless, in great extacy. - -The fourth time was immediately after breakfast. The few first -inspirations affected me so little that I thought Mr. Davy had given -me atmospheric air: but soon felt the warmth beginning about my chest, -and spreading upward and downward, so that I could feel its progress -over my whole frame. My heart did not beat so violently; my sensations -were highly pleasurable, not so intense or apparently local, but of -more unmingled pleasure than I had ever before experienced.[225] - - S. T. COLERIDGE. - -[225] The doses in these experiments were from five to seven quarts. - - -VIII. _Detail of_ MR. WEDGWOOD. - -July 23, I called on Mr. Davy at the Medical Institution, who asked -me to breathe some of the nitrous oxide, to which I consented, being -rather a sceptic as to its effects, never having seen any person -affected. I first breathed about six quarts of air which proved to be -only common atmospheric air, and which consequently produced no effect. - -I then had 6 quarts of the oxide given me in a bag undiluted, and -as soon as I had breathed three or four respirations, I felt myself -affected and my respiration hurried, which effect increased rapidly -until I became as it were entranced, when I threw the bag from me and -kept breathing on furiously with an open mouth and holding my nose -with my left hand, having no power to take it away though aware of -the ridiculousness of my situation. Though apparently deprived of all -voluntary motion, I was sensible of all that passed, and heard every -thing that was said; but the most singular sensation I had, I feel it -impossible accurately to describe. It was as if all the muscles of the -body were put into a violent vibratory motion; I had a very strong -inclination to make odd antic motions with my hands and feet. When the -first strong sensations went off, I felt as if I were lighter than the -atmosphere, and as if I was going to mount to the top of the room. I -had a metallic taste left in my mouth, which soon went off. - -Before I breathed the air, I felt a good deal fatigued from a very -long ride I had had the day before, but after breathing, I lost all -sense of fatigue. - - -IX. _Detail of_ MR. GEORGE BURNET. - -I had never heard of the effects of the nitrous oxide, when I breathed -six quarts of it. I felt a delicious tremor of nerve, which was rapidly -propagated over the whole nervous system. As the action of inhaling -proceeds, an irresistible _appetite_ to repeat it is excited. There is -now a general swell of sensations, vivid, strong, and inconceivably -pleasurable. They still become more vigorous and glowing till they are -communicated to the brain, when an ardent flush overspreads the face. -At this moment the tube inserted in the air-bag was taken from my -mouth, or I must have fainted in extacy. - -The operation being over, the strength and turbulence of my sensations -subsided. To this succeeded a state of feeling uncommonly serene and -tranquil. Every nerve being gently agitated with a lively enjoyment. -It was natural to expect that the effect of this experiment, would -eventually prove debilitating. So far from this I continued in a state -of high excitement the remainder of the day after two o’clock, the -time of the experiment, and experienced a flow of spirits not merely -chearful, but unusually joyous. - - GEORGE BURNET. - - -X. _Detail of_ MR. T. POPLE. - -A disagreeable sensation as if breaking out into a profuse -perspiration, tension of the tympanum, cheeks and forehead; almost -total loss of muscular power; afterwards increased powers both of -body and mind, very vivid sensations and highly pleasurable. Those -pleasant feelings were not new, they were felt, but in a less degree, -on ascending some high mountains in Glamorganshire. - -On taking it the second time, there was a disagreeable feeling about -the face. In a fewseconds, the feelings became pleasurable; all the -faculties absorbed by the fine pleasing feelings of existence without -consciousness; an involuntary burst of laughter. - - THOMAS POPLE. - - -XI. _Detail of_ MR. HAMMICK. - -Having never heard any thing of the mode of operation of nitrous oxide, -I breathed gas in a silk bag for some time, and found no effects, but -oppression of respiration. Afterwards Mr. Davy told me that I had been -breathing atmospheric air. - -In a second experiment made without knowing what gas was in the bag, -I had not breathed half a minute, when from the extreme pleasure I -felt, I unconciously removed the bag from my mouth; but when Mr. Davy -offered to take it from me, I refused to let him have it, and said -eagerly, “let me breathe it again, it is highly pleasant! it is the -strongest stimulant I ever felt!“ I was cold when I began to respire, -but had immediately a pleasant glow extending to my toes and fingers. I -experienced from the air a pleasant taste which I can only call sweetly -astringent; it continued for some time: the sense of exhilaration was -lasting. This air Mr. Davy told me was nitrous oxide. - -In another experiment, when I breathed a small dose of nitrous oxide, -the effects were slight, and sometime afterwards I felt an unusual -yawning and languor. - -The last time that I breathed the gas, the feelings were the most -pleasurable I ever experienced; my head appeared light, there was a -great warmth in the back and a general unusual glow; the taste was -distinguishable for some time as in the former experiment. My ideas -were more vivid, and followed the natural order of association. I could -not refrain from muscular action. - - STEPHEN HAMMICK, Junr. - _Sept. 15th._ - - -XII. _Detail of_ DR. BLAKE. - -Dr. Blake inhaled about six quarts of the air, was affected during -the process of respiring it with a slight degree of vertigo, which -was almost immediately succeeded by a thrilling sensation extending -even to the extremities, accompanied by a most happy state of mind and -highly pleasurable ideas. He felt a great propensity to laugh, and -his behaviour in some measure appeared ludicrous to those around him. -Muscular power seemed agreeably increased, the pulse acquired strength -and firmness, but its frequency was somewhat diminished. He perceived -rather an unpleasant taste in the mouth and about the fauces for -some hours afterwards, but in every other respect, his feelings were -comfortable during the remainder of the day. - - _December, 30th._ - To MR. DAVY. - - -XIII. _Detail of_ MR. WANSEY. - -I breathed the gas out of a silk bag, believing it to be nitrous oxide, -and was much surprised to find that it produced no sensations. After -the experiment, Mr. Davy told me it was common air. - -I then breathed a mixture of common air and nitrous oxide. I felt a -kind of intoxication in the middle of the experiment, and stopping to -express this, destroyed any farther effects. - -I now breathed pure nitrous oxide; the effect was gradual, and I at -first experienced fulness in the head, and afterwards sensations so -delightful, that I can compare them to no others, except those which -I felt (being a lover of music) about five years since in Westminster -Abbey, in some of the grand choruses in the Messiah, from the united -powers of 700 instruments of music. I continued exhilarated throughout -the day, slept at night remarkably sound, and experienced when I awoke -in the morning, a recurrence of pleasing sensation. - -In another experiment, the effects was still greater, the pulse was -rendered fuller and quicker, I felt a sense of throbbing in the head -with highly pleasurable thrillings all over the frame. The new feelings -were at last so powerful as to absorb all perception. I distinguished -during and after the experiment, a taste on the tongue, like that -produced by the contact of zinc and silver. - - HENRY WANSEY. - - -XIV. _Detail of_ MR. RICKMAN. - -On inhaling about six quarts, the first altered feeling was a tingling -in the elbows not unlike the effect of a slight electric shock. Soon -afterwards, an involuntary and provoking dizziness as in drunkenness. -Towards the close of the inhalation, this symptom decreased; though -the nose was still involuntary held fast after the air-bag was -removed. The dose was probably an undercharge, as no extraordinary -sensation was felt more than half a minute after the inhalation. - - J. RICKMAN. - - -XV. _Detail of_ MR. LOVELL EDGWORTH. - -My first sensation was an universal and considerable tremor. I then -perceived some giddiness in my head, and a violent dizziness in my -sight; those sensations by degrees subsided, and I felt a great -propensity to bite through the wooden mouth-piece, or the tube of the -bag through which I inspired the air. After I had breathed all the air -that was in the bag, I eagerly wished for more. I then felt a strong -propensity to laugh, and did burst into a violent fit of laughter, and -capered about the room without having the power of restraining myself. -By degrees these feelings subsided, except the tremor which lasted -for an hour after I had breathed the air, and I felt a weakness in my -knees. The principal feeling through the whole of the time, or what -I should call the characteristical part of the effect, was a total -difficulty of restraining my feelings, both corporeal and mental, or in -other words, not having any command of one’self. - - -XVI. _Detail of_ MR. G. BEDFORD. - -I inhaled 6 quarts. Experienced a sensation of fulness in the -extremities and in the face, with a desire and power of expansion of -the lungs very pleasurable. Feelings similar to intoxication were -produced, without being disagreeable. When the bag was taken away, an -involuntary though agreeable laughter took place, and the extremities -were warm. - -In about a quarter of an hour after the above experiment, I inhaled -8 quarts. The warmth and fulness of the face and extremities were -sooner produced during the inspiration. The candle and the persons -about me, assumed the same appearances as took place during the effect -produced by wine, and I could perceive no determinate outline. The -desire and power to expand the lungs was increased beyond that in the -former experiment, and the whole body and limbs seemed dilated without -the sense of tension, it was as if the bulk was increased without -any addition to the specific gravity of the body, which was highly -pleasant. The provocation to laughter was not so great as in the former -experiment, and when the bag was removed, the warmth almost suddenly -gave place to a coldness of the extremities, particularly of the hands -which were the first to become warm during the inspiration. A slight -sensation of fulness not amounting to pain in the head, has continued -for some minutes. After the first experiment, a sensation in the wrists -and elbows took place, similar to that produced by the electric shock. - - G. C. BEDFORD. - _March 30th, 1800._ - - -XVII. _Detail of_ MISS RYLAND. - -After having breathed five quarts of gas, I experienced for a short -time a quickness and difficulty of breathing, which was succeeded by -extreme languor, resembling fainting, without the very unpleasant -sensation with which it is usually attended. It entirely deprived me of -the power of speaking, but not of recollection, for I heard every thing -that was said in the room during the time; and Mr. Davy’s remark “that -my pulse was very quick and full.“ When the languor began to subside, -it was succeeded by restlessness, accompanied by involuntary muscular -motions. I was warmer than usual, and very sleepy for several hours. - - -XVIII. _Letter from_ MR. M. M. COATES. - -I will, as you request, endeavour to describe to you the effect -produced on me last Sunday fe’nnight by the nitrous oxide, and will at -the same time tell you what was the previous state of my mind on the -subject. - -When I sat down to breathe the gas, I believed that it owed much of -its effect to the predisposing agency of the imagination, and had no -expectation of its sensible influence on myself. Having ignorantly -breathed a bag of common air without any effect, my doubts then arose -to positive unbelief. - -After a few inspirations of the nitrous oxide, I felt a fulness in -my head, which increased with each inhalation, until, experiencing -symptoms which I thought indicated approaching fainting, I ceased to -breathe it, and was then confirmed in my belief of its inability to -produce in me any pleasurable sensation. - -But after a few seconds, I felt an immoderate flow of spirits, and an -irresistible propensity to violent laughter and dancing, which, being -fully conscious of the violence of my feelings, and of their irrational -exhibition, I made great but ineffectual efforts to restrain; this was -my state for several minutes. During the rest of the day, I experienced -a degree of hilarity altogether new to me. For six or seven days -afterwards, I seemed to feel most exquisitely at every nerve, and was -much indisposed to my sedentary pursuits; this acute sensibility has -been gradually diminishing; but I still feel somewhat of the effects of -this novel agent. - - Your’s truly, - M. M. COATES. - - To Mr. DAVY. - _June 11th, 1800._ - - -DIVISION III. - - _ABSTRACTS from ADDITIONAL DETAILS.—OBSERVATIONS - on the EFFECTS of NITROUS OXIDE, by Dr. - BEDDOES.—CONCLUSION._ - - -I. _Abstracts from additional Details._ - -The trials related in the following abstracts, have been chiefly made -since the publication of Dr. Beddoes’s Notice. Many of the individuals -breathed the gas from pure curiosity. Others with a disbelief of its -powers. - - * * * * * - -Mr. WYNNE, M. P. breathed five quarts of diluted nitrous oxide, without -any sensation. Six quarts produced fulness in the chest, heat in -the hands and feet, and sense of tension in the fingers, slight but -pleasant sensations. Seven quarts produced no new or different effects. - -Mr. MACKINTOSH several times breathed nitrous oxide. He had sense of -fulness in the head, thrillings, tingling in the fingers, and generally -pleasurable feelings. - -Mr. JOHN CAVE, Junr. from breathing four quarts of nitrous oxide, felt -sensations as from superior wine, and general pleasant feelings. - -Mr. MICHAEL CASTLE, from five quarts, experienced sensations of heat -and thrilling, general spirits heightened considerably as from wine; -afterwards, slight pain in the back of the head. - -Mr. H. CARDWELL, from five quarts, had feelings so pleasurable as -almost to destroy consciousness; almost convulsed with laughter; for a -long time could not think of the feeling without laughing; sensation of -lightness for some time after. - -Mr. JARMAN, from five quarts, great pleasure, laughter, certainly -better spirits, glow in the cheeks which continued long. - -The gentleman who furnished the preceding detail, had heard of -the effects of nitrous oxide, and was prepared to experience new -sensations: I therefore gave him a bag of common air which he respired, -believing it to be nitrous oxide; and was much surprised that no -effects were produced. He then breathed five quarts of nitrous oxide, -and after the experiment, gave this account of his sensations. - -Rev. W. A. CANE, after inhaling the gas, felt the most delicious -sensations accompanied by a thrill through every part of his body. -He did not think it possible so charming an effect could have been -produced. He had heard of the gas; but the result of the experiment far -exceeded his expectations. - -_May 6th_, 1800. - - * * * * * - -Mr. JOSEPH PRIESTLEY from breathing nitrous oxide, generally had -unpleasant fulness of the head and throbbing of the arteries, which -prevented him from continuing the respiration. - -Dr. BEDDOES mentioned in his Notice, that Mr. JOSIAH WEDGWOOD and Mr. -THOMAS WEDGWOOD experienced rather unpleasant feelings from the gas. -Mr. JOSIAH WEDGWOOD has since repeated the trial, the effects were -powerful, but not in the slighted degree pleasant. - -Mr. R. BOULTON and Mr. G. WATT have been much less affected than any -individuals. - -Many other persons have respired the gas, but as their accounts contain -nothing unnoticed in the details, it is useless to particularise them. - -The cases of all the males who have been unpleasantly affected since -we have learnt to prepare the gas with accuracy, are related in this -Section and in the last Division. Those who have been pleasurably -affected after a fair trial and whose cases are not noticed, generally -experienced fulness in the head, heat in the chest, pleasurable -thrillings, and consequent exhilaration. - -To persons who have been unaccustomed to breathe through a tube, we -have usually given common air till they have learnt to respire with -accuracy: and in cases where the form of the mouth has prevented the -lips from being accurately closed on the breathing tube, by the advice -of Mr. Watt, we have used a tin plate conical mouth-piece fixed to -the cheeks, and accurately adapted to the lips; by means of which -precautions, all our later trials have been perfectly conclusive. - - -II. _Of the effects of Nitrous Oxide upon persons inclined to -hysterical and nervous affections._ - -The case of Miss—— N. and other cases, detailed by Dr. Beddoes in his -Notice, seemed to prove that the action of nitrous oxide was capable of -producing hysterical and nervous affections in delicate and irritable -constitutions. - -On this subject, we have lately acquired additional facts. - -Miss E. a young lady who had been subject to hysteric fits, breathed -three quarts of nitrous oxide mingled with much common air, and felt -no effects but a slight tendency to fainting. She then breathed four -quarts of pure nitrous oxide: her first inspirations were deep, her -last very feeble. At the end she dropt the bag from her lips, and -continued for some moments motionless. Her pulse which at the beginning -of the experiment was strong, appeared to me to be at this time, -quicker and weaker. She soon began to move her hands and talked for -some minutes incoherently, as if ignorant of what had passed. In less -than a quarter of an hour, she had recovered, but could give no account -of her sensations. A certain degree of languor continued through the -day. - -A young lady who never had hysterical attacks, wished to breathe the -gas. I informed her of the disagreeable effects it had sometimes -produced, and advised her if she had the slightest tendency to nervous -affection, not to make the trial. She persisted in her resolution. - -To ascertain the influence of imagination, I first gave her a bag of -common air, which she declared produced no effect. I then ordered for -her a quart of nitrous oxide mingled with two quarts of common air; but -from the mistake of the person who prepared it, three quarts of nitrous -oxide were administered with one of common air. She breathed this for -near a minute, and after the experiment, described her sensations as -unpleasant, and said she felt at the moment as if she was dying. The -unpleasant feelings quickly went off, and a few minutes after, she had -apparently recovered her former state of mind. In the course of the -day, however, a violent head-ache came on, and in the evening after she -had taken a medicine which operated violently, hysterical affections -were produced, followed by great debility. They occasionally returned -for many days, and the continued weak and debilitated for a great -length of time. - -Mrs. S. a delicate lady, liable to nervous affections who had heard -of the cases just detailed, chose to breathe the gas. By three quarts -she was thrown into a trance, which lasted for three or four minutes. -On recovering, the could give no account of her feelings, and had some -languor for half an hour afterwards. - -These phænomena have rendered us cautious in administering the gas to -delicate females. In a few instances however, it has been taken by -persons of this class, and even by those inclined to hysterical and -nervous complaints with pleasurable effects. - -Miss L. a young lady who had formerly had hysterical fits, breathed a -quart of nitrous oxide with three quarts of common air without effects. -Two quarts of nitrous oxide with one of common air produced a slight -giddiness; four quarts of nitrous oxide produced a fit of immoderate -laughter, which was succeeded by slight exhilaration, her spirits were -good throughout the day, and no depression followed. - -Miss B. Y—— and Miss S. Y—— both delicate but healthy young ladies, -were affected very pleasantly; each by three quarts of nitrous oxide, -the first time of respiring it. Miss B Y—— continued exhilarated and in -high spirits for some hours after the dose. Miss S. Y—— had a slight -head-ache, which did not go off for some hours. - -Mrs. F. inclined to be hysterical, breathed four quarts of nitrous -oxide mingled with common air. She was giddy and described her feelings -as odd; but had not the slightest languor after the experiment. - - -III. _Observations on the effects of Nitrous Oxide, by_ DR. BEDDOES. - -Neither my notes nor my recollection supply much in addition to what -I formerly stated in the _Notice of Observations at the Pneumatic -Institution_. _Longman._ The gas maintains its first character as -well in its effects on me, as in the benefit it confers on some of -the paralytic, and the injury it does or threatens to the hysterical -and the exquisitely sensible. I find that five or six quarts operate -as powerfully as ever. I seem to make a given quantity go farther by -holding my breath so that the gas may be absorbed in a great degree -without returning into the bag, and therefore, be as little heated -before inspiration as possible.—This may be fancy. - -After innumerable trials, I have never once felt lassitude or -depression[226]. Most commonly I am sensible of a grateful glow _circum -præcordia_. This has continued for hours.—In two or three instances -only has inhalation failed to be followed by pleasurable feeling, it -has never been followed by the contrary. On a few occasions before the -gas was exhausted, I have found it impossible to continue breathing. - -[226] Of the facts on which Brown founded his law of indirect debility, -no prudent man will lose sight either in practising or studying -medicine. They are incontrovertible.—And our new facts may doubtless be -conciliated to the Brunonian doctrine. - -But to suppose that the expenditure of a quality or a substance or a -spirit, and its renewal or accumulation are the general principles of -animal phænomena, seems to me a grievous and baneful error. I believe -it often happens that excitement and excitability increase, and that -they oftener decrease together;—In short, without generalizing in -a manner, of which Brown and similar theorists had no conception, -our notions of the living world will in my opinion, continue to be -as confused as the elements are said to have been in chaos. On some -future occasion, I may presume to point out the region through which I -imagine the path to wind, that will lead the observers of some distant -generation to a point, whence they may enjoy a view of the subtle, busy -and intricate movements of the organic creation as clear as Newton -obtained of the movements of the heavenly masses. - -The pulse at first becomes fuller and stronger. Whenever, after -exposure to a cold wind, the warmth of the room has created a glow in -the cheeks, the gas has increased this to strong flushing—which common -air breathed in the same way, failed to do. - -Several times I have found that a cut which had ceased to be painful -has smarted afresh, and on taking two doses in succession, the smarting -ceased in the interval and returned during the second respiration. I -had no previous expectation of the first smarting. - -The only time I was near rendering myself insensible to present -objects by very carefully breathing several doses in quick succession, -I forcibly exclaimed, TONES!—In fact, besides a general thrilling, -there seemed to be quick and strong alterations in the degree of -illumination of all surrounding objects; and I felt as if composed -of finely vibrating strings. On this occasion, the skin seemed in a -state of constriction and the lips glued to the mouth-piece, and the -mucous membrane of the lungs contracted, but not painfully. However, no -constriction or corrugation of the skin could be seen. I am conscious -of having made a great number of observations while breathing, which I -could never recover. - -Immediately afterwards I have often caught myself walking with a -hurried step and busy in soliloquy. The condition of general sensation -being as while hearing chearful music, or after good news, or a -moderate quantity of wine. - -Mr. John Cave, Junr. and his three friends, as well as others, -compared the effects to Champagne. Most persons have had the idea -of the effect of fermented liquors excited by the gas. It were to be -wished that we had, for a standard of comparison, observations on the -effect of these liquors as diversified and as accurate as we have -obtained concerning the gas; nor would more uniformity in the action -of these substances be observed if the enquiry were strictly pursued. -Opium and spirits seem, in particular states to sicken and distress -in the first instance; how differently does wine at an early hour and -fasting act upon those who are accustomed to take it only after dinner! - -I thought it might be an amusing spectacle to see the different tints -of blood flowing from a wound by a leech in consequence of breathing -different airs. The purple from the nitrous oxide was very evident. -Oxygene, we thought, occasioned a quicker flow and brighter color in -the blood. In another experiment, an inflamed area round the puncture -from a leech applied the day before, was judged by several spectators -to become much more crimson on the respiration of about 20 quarts -of oxygene gas, which possibly acts more powerfully on inflamed -parts.[227] These and many similar experiments, require to be repeated -on the blood of single arteries opened in warm and cold animals. - -[227] After writing this, I was present when an invalid, in whose foot -the gout, after much wandering, had at last fixed, breathed 12 quarts -of oxygene gas. While breathing, he eagerly pointed to the inflamed -leg; and afterwards said he had felt in it a new sensation, somewhat -like tension.—I never had seen oxygene respired where there was so much -local inflammation. - -June 18. After four quarts of oxygene with 6 of nitrous oxide and -then 6 of nitrous oxide alone, violent itching of the wounds made by -the leech; and redness and tumour.—Both had healed, and I did not -expect to feel any thing more from them.—I tried this again with two -doses of nitrous oxide—The yellow halo round one wound changed to -crimson, and there was so much stinging and swelling that I feared -suppuration.—Absorption here was rapid. - -It has appeared to me that I could hold my breath uncommonly long when -respiring oxygene gas mixed with nitrous oxide. While trying this -to-day, (17th June), I thought the sense of smell much more acute after -the nitrous oxide than before I began to respire at all; and then I -felt conscious that this increased acuteness had before repeatedly -occurred—a fact very capable, I apprehend, of a pneumatological -interpretation. - -Time by my feelings has always appeared longer than by a watch. - -I thought of trying to observe whether while I alternately breathed -quantities of nitrous oxide and oxygene gas and common air, I could -observe any difference in the operation of a blister beginning to -bite the skin. It would be of consequence to ascertain the effect -of regulating by compression the flow of blood, while stimulants of -various kinds (and heated bodies among the rest) were applied to or -near the extremities—because in erisipelas and various inflammatory -affections, a ready and pleasant cure might be effected by partial -compression of the arteries going to the diseased part; and a great -improvement in practice thus obtained. - -But I should run into an endless digression, were I to enumerate -possible physiological experiments with artificial airs, or to -speculate on the mechanical improvement of medicine, which at present -as far as mechanical means of affecting the living system are -concerned, is with us in a state that would almost disgrace a nation of -savages. - - -IV. CONCLUSION. - -From the facts detailed in the preceding pages, it appears that -the immediate effects of nitrous oxide upon the living system, are -analogous to those of diffusible stimuli. Both increase the force of -circulation, produce pleasurable feeling, alter the condition of the -organs of sensation, and in their most extensive action destroy life. - -In the mode of operation of nitrous oxide and diffusible stimuli, -considerable differences however, exist. - -Diffusible stimuli act immediately on the muscular and nervous fibre. -Nitrous oxide operates upon them only by producing peculiar changes in -the composition of the blood. - -Diffusible stimuli affect that part of the system most powerfully to -which they are applied, and act on the whole only by means of its -sympathy with that part. Nitrous oxide in combination with the blood, -is universal in its application and action. - -We know very little of the nature of excitement; as however, life -depends immediately on certain changes effected in the blood in -respiration, and ultimately on the supply of certain nutritive matter -by the lymphatics; it is reasonable to conclude, that during the action -of simulating substances, from the increased force of circulation, not -only more oxygene and perhaps nitrogene must be combined with the blood -in respiration,[228] but likewise more fluid nutritive matter supplied -to it in circulation. - -[228] See Dr. Beddoes’s _Considerations_, _part_ 1. _page_ 26. His -observations in the note in the last section, will likewise apply -here.—Is not healthy living action dependant upon a certain equilibrium -between the principles supplied to the blood by the pulmonary veins -from respiration and by the lymphatics from absorption? Does not -sensibility more immediately depend upon respiration? Deprive an -animal under stimulation, of air, and it instantly dies; probably if -absorption could be prevented, it would likewise speedily die. It would -be curious to try whether intoxication from fermented liquors cannot be -prevented by breathing during their operation, an atmosphere deprived -of part of its oxygene. - -By this oxygene and nutritive matter excitability may be kept up: and -exhaustion consequent to excitement only produced, in consequence of a -deficiency of some of the nutritive principles, which are supplied by -absorption. - -When nitrous oxide is breathed, nitrogene (a principle under common -circumstances chiefly carried into the blood by the absorbents in fluid -compounds) is supplied in respiration; a greater quantity of oxygene -is combined with the blood than in common respiration, whilst less -carbonic acid and probably less water are evolved. - -Hence a smaller quantity of nutritive matter is probably required from -the absorbents during the excitement from nitrous oxide, than during -the operation of stimulants; and in consequence, exhaustion from the -expenditure of nutritive matter more seldom occasioned. - -Since Research III. has been printed, I have endeavoured to ascertain -the quantities of nitrogene produced when nitrous oxide is respired -for a considerable time. In one experiment, when I breathed about four -quarts of gas in a glass bell over impregnated water for near a minute, -it was diminished to about two quarts; and the residuum extinguished -flame. - -Now the experiments in Research II. prove that when nitrous oxide is -decomposed by combustible bodies, the quantity of nitrogene evolved is -rather greater in volume than the pre-existing nitrous oxide. Hence -much of the nitrogene taken into the system during the respiration of -nitrous oxide, must be either carried into new combinations, or given -out by the capillary vessels through the skin. - -It would be curious to ascertain whether the quantity of ammoniac in -the saline matters held in solution by the secreted fluids is increased -after the respiration of nitrous oxide. Experiments made upon the -consumption of nitrous oxide mingled with atmospheric air by the -smaller animals, would go far to determine whether any nitrogene is -given out through the skin. - -The various effects of nitrous oxide upon different individuals and -upon the same individuals at different times, prove that its powers are -capable of being modified both by the peculiar condition of organs, and -by the state of general feeling. - -Reasoning from common phænomena of sensation, particularly those -relating to heat, it is probable that pleasurable feeling is uniformly -connected with a moderate increase of nervous action; and that this -increase when carried to certain limits, produces mixed emotion or -sublime pleasure; and beyond those limits occasions absolute pain. - -Comparing the facts in the last division, it is likely that individuals -possessed of high health and little sensibility, will generally be -less pleasurably affected by nitrous oxide than such as have more -sensibility, in whom the emotions will sometimes so far enter the -limits of pain as to become sublime;[229] whilst the nervous action in -such as have exquisite sensibility, will be so much increased as often -to produce disagreeable feeling. - -Modification of the powers of nitrous oxide by mixture of the gas -with oxygene or common air, will probably enable the most delicately -sensible to respire it without danger, and even with pleasurable -effects: heretofore it has been administered to such only in its pure -form or mingled with small quantities of atmospheric air, and in its -pure form even the most robust are unable to respire it with safety for -more than five minutes. - -[229] Sublime emotion with regard to natural objects, is generally -produced by the connection of the pleasure of beauty with the passion -of fear. - -The muscular actions[230] sometimes connected with the feelings -produced by nitrous oxide, seem to depend in a great measure upon the -particular habits of the individual; they will usually be of that kind -which is produced either by common pleasurable feelings or strong -emotions. - -[230] The immortal HARTLEY has demonstrated that all our motions are -originally automatic, and generally produced by the action of tangible -things on the muscular fibre. - -The common actions of adults may be distinguished into two kinds; -voluntary actions, and mixed automatic actions. The first are -produced by ideas, or by ideas connected with passions. The second by -impression, or by pleasure and pain. - -In voluntary action, regular associations of ideas and muscular motions -exist: as when a chemist performs a pre-conceived experiment. - -In mixed automatic actions, the simple motions produced by impression -are connected with series of motions formerly voluntary, but now -produced without the intervention of ideas: as when a person -accustomed to play on the harpsichord, from accidentally striking -a key, is induced to perform the series of motions which produce a -well-remembered tune. - -Evidently the muscular actions produced by nitrous oxide are mixed -automatic motions. - -Hysterical affection is occasioned by nitrous oxide, probably only in -consequence of the strong emotion produced, which destroys the power of -the will, and calls up series of automatic motions formerly connected -with a variety of less powerful but similar feelings. - -The quickness of the operation of nitrous oxide, will probably render -it useful in cases of extreme debility produced by deficiency of -common exciting powers. Perhaps it may be advantageously applied -mingled with oxygene or common air, to the recovery of persons -apparently dead from suffocation by drowning or hanging. - -The only diseases in which nitrous oxide has been hitherto employed, -are those of deficient sensibility.—An account of its agency in -paralytic affections, will be speedily published by Dr. Beddoes. - -As by its immediate operation the tone of the irritable fibre is -increased, and as exhaustion rarely follows the violent muscular -motions sometimes produced by it, it is not unreasonable to expect -advantages from it in cases of simple muscular debility. - -The apparent general transiency of its operation in the pure form -in single doses has been considered as offering arguments against -its power of producing lasting changes in the constitution. It will, -however, be easy to keep up excitement of different degrees of -intensity for a great length of time, either by administering the -unmingled gas in rapid successive doses, or by preserving a permanent -atmosphere, containing different proportions of nitrous oxide and -common air, by means of a breathing chamber.[231] That single doses -nevertheless, are capable of producing permanent effects in some -constitutions, is evident, as well from the hysterical cases as from -some of the details—particularly that of Mr. M. M. Coates. - -[231] See R. IV. Div. I. page 478. - -As nitrous oxide in its extensive operation appears capable of -destroying physical pain, it may probably be used with advantage during -surgical operations in which no great effusion of blood takes place. - -From the strong inclination of those who have been pleasantly affected -by the gas to respire it again, it is evident, that the pleasure -produced, is not lost, but that it mingles with the mass of feelings, -and becomes intellectual pleasure, or hope. The desire of some -individuals acquainted with the pleasures of nitrous oxide for the gas -has been often so strong as to induce them to breathe with eagerness, -the air remaining in the bags after the respiration of others. - -As hydrocarbonate acts as a sedative,[232] and diminishes living action -as rapidly as nitrous oxide increases it, on the common theory of -excitability[233] it would follow, that by differently modifying the -atmosphere by means of this gas and nitrous oxide, we should be in -possession of a regular series of exciting and depressing[234] powers -applicable to every deviation of the constitution from health: but -the common theory of excitability is most probably founded on a false -generalisation. The modifications of diseased action may be infinite -and specific in different organs; and hence out of the power of agents -operating on the whole of the system. - -[232] R. IV. Div. I. page 467. - -[233] That of Brown modified by his disciples. - -[234] Supposing the increase or diminution of living action when -produced by different agents, uniform, similar and differing only in -degree; it would follow, that certain mixtures of hydrocarbonate and -nitrous oxide, or hydrogene and nitrous oxide, ought to be capable of -supporting the life of animals for a much longer time than pure nitrous -oxide. From the experiments in Res. III. Div. I. it appears however, -that this is not the case. - -It would seem, that in life, a variety of different corpuscular changes -are capable of producing phænomena apparently similar; so that in the -science of living action, we are incapable of reasoning concerning -causes from effects. - -Whenever we attempt to combine our scattered physiological facts, we -are stopped by the want of numerous intermediate analogies; and so -loosely connected or so independant of each other, are the different -series of phænomena, that we are rarely able to make probable -conjectures, much less certain predictions concerning the results of -new experiments. - -An immense mass of pneumatological, chemical, and medical information -must be collected, before we shall be able to operate with certainty, -on the human constitution. - -Pneumatic chemistry in its application to medicine, is an art in -infancy, weak, almost useless, but apparently possessed of capabilities -of improvement. To be rendered strong and mature, she must be -nourished by facts, strengthened by exercise, and cautiously directed -in the application of her powers by rational scepticism. - - - - -APPENDIX. - - -No. I. - -_Effects of Nitrous Oxide on Vegetation._ - -In July 1799, I introduced two small plants of spurge into nitrous -oxide, in contact with a little water over mercury; after remaining -in it two days, they preserved their healthy appearance, and I could -not perceive that any gas had been absorbed. I was prevented by an -accident, from keeping them longer in the gas. - -A small plant of mint introduced into nitrous oxide and exposed to -light, in three days became dark olive and spotted with brown; and in -about six days was quite dead.—Another similar plant, kept in the dark -in nitrous oxide, did not alter in color for five days, and at the end -of seven days, was only a little yellower than before. I could not -ascertain whether any gas had been absorbed. - -I introduced into nitrous oxide through water, a healthy budding rose, -thinking that its colors might be rendered brighter by the gas. I was -disappointed, it very speedily faded and died; possibly injured by the -solution of nitrous oxide in water. - -Of two rows of peas just appearing above ground; I watered one with -solution of nitrous oxide in water, and the other with common water -daily, for a fortnight. At the end of this time, I could perceive no -difference in their growth, and afterwards they continued to grow -equally fast. - -I introduced through water into six phials, one of which contained -hydrogene, one oxygene, one common air, one hydrocarbonate, one -carbonic acid, and one nitrous oxide, six similar plants of mint, -their roots being in contact with water and their leaves exposed to -light. - -The plant in carbonic acid began to fade in less than two days, and -in four was dead. That in hydrogene died in less than five days; that -in nitrous oxide did not fade much for the first two days, but on -the third, drooped very much, and was dead at the same time as that -in hydrogene. The plant in oxygene for the first four days, looked -flourishing and was certainly of a finer green than before, gradually -however, its leaves became spotted with black and dropped off one by -one, till at the end of ten days they had all disappeared. At this -time the plant in common air looked sickly and yellow, whilst that in -hydrocarbonate was greener and more flourishing than ever. - -I have detailed these experiments not on account of any important -conclusions that may be drawn from them; but with a view of inducing -others to repeat them, and to examine the changes effected in the -gases. If it should be found by future experiments, that hydrocarbonate -generally increased vegetation, it would throw some light upon the use -of manures, containing putrefying animal and vegetable substances, from -which this gas is perpetually evolved. - -The chemistry of vegetation though immediately connected with -agriculture, the art on which we depend for subsistence, has been but -little investigated. The discoveries of Priestley and Ingenhousz, seem -to prove that it is within the reach of our instruments of experiment. - - -No. II. - -APPROXIMATIONS TO THE _Composition and Weight of the aëriform_ - -_COMBINATIONS of NITROGENE_ - -At temperature 55°, and atmospheric pressure 30. - - +------+-------+--------------+---+------+------+---------+---------+ - | | |100 Cubic In. | |grains| |Nitrogene| Oxygene | - | | +--------------+---+------+------+---------+---------+ - |Nitro-| With | Nitrogene | | 30.04| | | | - | gene | Oxy- | Oxygene | | 35.06| | | | - | | gene +--------------+---+------+ 100 +---------+---------+ - | | |Atmospher. air| w | 31.10|grains| 73.00 | 27.00 | - | | |Nitrous oxide | e | 50.20| are | 63.30 | 36.70 | - | | |Nitrous gas | i | 34.26|com- | 44.05 | 55.95 | - | | |Nitric acid | g | 76.00| posed| 29.50 | 70.50 | - | | | | h | | of +---------+---------+ - | | | | | | |Nitrogene|Hydrogene| - | +-------+--------------+---+------+ +---------+---------+ - | | With | | | | | | | - | | hydro-|Ammoniac | | 18.05| | 80.00 | 20.00 | - | | gene | | | | | | | - +------+-------+--------------+---+------+------+---------+---------+ - - -No. III. - -_Additional Observations._ - -_a._ In Res. 1st. Div. IV. Sect. III. in the analysis of nitrous gas by -pyrophorus, as no absorption took place when the residual nitrogene was -exposed to water, I inferred that if any carbonic acid was formed it -was in quantity so minute, as to be unworthy of notice. A few days ago, -I compleatly decomposed a quantity of nitrous gas by pyrophorus, when -the residual nitrogene was exposed to solution of strontian, the fluid -became slightly clouded; but no perceptible absorption took place. - -_b._ If there was the least probability in any of Dr. Girtanner’s -speculations on the composition of Azote,[235] the experiments on the -exhausted capacity[236] of the lungs in Res. III. might be supposed -inconclusive. But there appears to be no more reason for supposing -that hydrogene is converted into nitrogene by respiration, than for -supposing that it is converted into water, carbonic acid or oxygene; -for all these products are evolved when that gas is respired. From -the comparison of Exp. 1 with Exp. 3, Res. iii. Div. ii. Sec. 4, it -is almost demonstrated that no ascertainable change is effected in -hydrogene by respiration. The experiment of the accurate Scheele in -which hydrogene after being respired thirty times in a bladder wholly -lost its inflammability, may be easily accounted for from its mixture -with the residual gases of the lungs. - -[235] Annales de Chimie, 100; and Mr. Tilloch’s Phil. Magazine. 24. - -[236] I regret much that I could not procure Dr. Menzies’s observations -on Respiration, while I was making the experiments on the capacity of -the lungs: they would probably have saved me some labor. - -About a fortnight ago, I respired, after forced voluntary exhaustion of -my lungs, my nose being accurately closed, three quarts of hydrogene in -a silk bag, at four intervals, for near five minutes. After this it was -highly inflammable, and burnt with a greenish white flame in contact -with the atmosphere; but was not so explosive as before.[237] - -[237] If loosely combined carbon exists in venous blood, hydrogene may -probably dissolve a portion of it when respired and become slightly -carbonated. At least there is as much probability in the supposition -that carbon in loose affinity may combine with hydrogene at 98° as that -it may combine with oxygene. - -_c._ From what we have lately heard of the curious experiments of Mr. -Volta and Mr. Carlisle, it is very probable that the conversion of -nitrous gas into nitrous oxide when exposed to wetted zinc, copper -and tin, in contact with mercury, as described in Res. I. Div. V. may -in some measure depend on the action of the galvanic fluid. Whilst I -was engaged in the experiments on this conversion, Dr. Beddoes[238] -mentioned to me some curious facts noticed by Humboldt and Ritter, -relating to the oxydation of metals by the decomposition of water, -which induced me to examine the phænomena with more attention than I -should have otherwise done.—I recollect observing that some of the -wetted zinc filings in nitrous gas on the side of the jar not in -contact with the surface of mercury, were very slowly oxydated. Whilst -on the surface of the mercury where small globules of that substance -were mingled with the filings of zinc, the decomposition went on much -more rapidly; possibly through the medium of the moisture, a series of -galvanic circles were formed. - -[238] Dr. BEDDOES has since favoured me with the following account of -these facts. - -“Mr. Humboldt (ueber die gereizte Faser I. 473, 1797) quotes part of a -letter from Dr. Ash, in which it is said that _if two finely polished -plates of homogeneous zinc be moistened and laid together, little -effect follows—but if zinc and silver be tried in the same way, the -whole surface of the silver will be covered with oxydated zinc. Lead -and quicksilver act as powerfully on each other, and so do iron and -copper._—Mr. Humboldt (p. 474) says that, in repeating this experiment, -he saw air-bubbles ascend, which he supposes to have been hydrogene gas -from the decomposition of water—When he placed zinc simply on moist -glass, the same phænomena took place, but more slowly and later. The -quantity of oxyd of zinc upon the glass alone was in 20 hours to that -on the silver as one to three. - -In a very ingenious but obscurely written tract by Mr. Ritter, -entitled, _Evidence that the galvanic action exists in organic nature_, -_8vo. Jena, 1800_—The author observes, that the care of Dr. Ash and -Mr. Humboldt that the metals should touch each other in as many points -as possible was superfluous, even if we could grant that two metallic -plates might be made by polishing, to touch in a number of points. -To shew that it was sufficient if by touching in one point only they -should form a compleat galvanic circle, he dropped a single drop of -distilled water upon the bust of a large silver coin. A piece of pure -zinc was placed with its one end on the edge of the coin, while the -other was supported by a bit of glass. The drop of water was neither in -contact with the glass nor with the point at which the metals touched. -The materials were left in this situation for four hours at the -temperature of 68°. On taking them apart, the water had become quite -milky and had half disappeared; and Mr. Ritter actually separated a -quantity of white oxide that had been produced in the experiment. - -The pieces of metal were cleaned and laid together in the same manner, -only that now a piece of paper was put between the metals at their -former point of contact. In four hours first, and afterwards in ten, a -faint ring of oxide only had been produced of which the quantity could -not be estimated, nor could it be separated. In this case, the zinc -had scarce lost any thing of its splendour; in the former it had been -corroded. In many repetitions of the experiment, he found that far more -oxide was formed when the metals touched, than when they were separated -to the slightest distance by an insolating body, even air. - -On exposing these apparatuses with somewhat more water to a -considerable heat for four minutes, the water in the interrupted circle -continued quite clear, while that in the other had become milk-white. - -The same phænomena were presented by other pairs of metals in a degree -proportional to their galvanic activity; viz. by zinc and molybdæna, -zinc and bismuth, zinc and copper, as also with tin and silver, tin -and molybdæna, and lead and silver. The experiment with tin was -particularly decisive, for when in contact with no other metal it was -scarcely at all oxydated by water, though oxydation took place when tin -was brought into contact with silver, and both were connected at the -other end by a drop of water—What therefore took place in Dr. Ash’s -experiment, arose from an aggregation of galvanic circles of different -forms. - -By the foregoing experiments, concludes Mr. Ritter, which though -capable of the most various modifications, uniformly coincide in -their main result, it is abundantly proved that _galvanic circles -can be formed of merely inorganic bodies, by whose completion there -is produced an action which ceases when the circle is opened_. The -manner in which this has been shewn, proves also that _this action can -effectuate sensible modifications in organic bodies_; and the process -by which these modifications have been effected, made it evident that -they _were not consequences of a momentary action of the circle, but -of an action that is kept up while the circle remains entire_; for the -process which brought this action under the cognizance of the senses -went on, while the circle was unbroken, and its figure not brought back -to that of a line. - -It is scarce necessary to observe that the experiments here quoted, are -far from being the only ones on which the above conclusions rest.” - - _T. B._ - - -_d._ In Res. II. Div. I. it is stated, that nitrous oxide during its -solution by common water, expels about ¹/₁₆ of atmospheric air the -volume of the water being unity. - -From the delicate experiments of Dr. Pearson, on the passage of the -electric spark through water, it appears however probable, that much -more than ¹/₁₆ of atmospheric air is sometimes held in solution by that -fluid,[239] possibly the whole of the air is not expelled by nitrous -oxide, owing to some unknown law of saturation by which an equilibrium -of affinity is produced, forming a triple compound. - -[239] Possibly a ratio exists between the solubility of gases in water, -and the solubility of water in gases. It is probable from Mr. Wm. -Henry’s curious experiments on the muriatic acid, that the absolute -quantity of water in _many_ gases, may be ascertained by means of its -decomposition by the electric spark. - - -No. IV. - -DESCRIPTION OF A MERCURIAL AIRHOLDER. - -Suggested by an inspection of Mr. WATT’S Machine for containing -Factitious Airs. - -_By WILLIAM CLAYFIELD_. - - -Several modes of counteracting the pressure of a decreasing column of -mercury having been thought of in conjunction with Mr. W. Cox, the -following was at last adopted as the most simple and effectual. - -Plate 1 Fig. 1, represents a section of the machine, which consists of -a strong glass cylinder A cemented to one of the same kind B, fitted -to the solid block C, into which the glass tube D is cemented for -conveying air into the moveable receiver E. - -The brass axis F, Fig. 2, having a double bearing at _a_, _a_, is -terminated at one end by the wheel G, the circumference of which is -equal to the depth of the receiver, so that it may be drawn to the -surface of the mercury by the cord _b_ in one revolution; to the other -end is fitted the wheel H, over which the balance cord _c_ runs in an -opposite direction in the spiral groove _e_, a front view of the wheel -H is shewn at Fig. 3. - -Having loaded the receiver with the weight I, something heavier than -may be necessary to force it through the mercury, it is balanced by -the small weight K, which hangs from that part of the spiral where the -radius is equal to that of the wheel G, from this point the radius -of the spiral must be increased in such proportion, that in every -part of its circuit, the weight K may be an exact counterpoise to the -airholder. In this way, so little friction will be produced, that -merely plunging the lower orifice of the tube D under mercury contained -in the small vessel L, will be sufficient to overcome every resistance, -and to force the gas discharged from the beak of a retort into the -receiver, where whatever may be its quantity, it will be subjected to -a pressure exactly corresponding to that of the atmosphere. The edge -of the wheel H being graduated, the balance cord _c_ may be made to -indicate its volume. - -Should it at any time be necessary to reduce the pressure to the medium -standard of the barometer, it may easily be done by graduating the -lower end of the tube D, and adding to the weights I or K, as may be -found necessary; the surface of the mercury in the tube pointing out -the increase or diminution. - -The concavity at the top of the internal cylinder is intended to -contain any liquid it may be thought proper to expose to the action of -the gas. - -The upper orifice _f_, with its ground stopper, is particularly useful -in conveying air from the retort _g_, with its curved neck, into the -receiver, without its passing through the tube D. In all cases where a -rapid extrication of gas is expected the retort _g_, should be firmly -luted to the orifice and the weight I, removed from the top of the -receiver, this by diminishing the pressure, will admit the gas to -expand freely in the airholder at the instant of its formation, and -prevent an explosion of the vessels. The same caution must be observed -whenever any inflammation of gas is produced by the electric spark. - -The air may be readily transferred through water or even mercury by the -tube _h_, Fig. 1. - -To prevent an absorption of mercury in case of a condensation taking -place in the retort made use of for generating air, Mr. Davy has -applied the stop-cock _i_, to which the neck is firmly luted. This -stop-cock is likewise of great service in saturating water with acid or -alkaline gases, which may be effected by luting one end of the tube _k_ -to the stop-cock, and plunging the other into the fluid in the small -vessel _l_, cemented at top, and terminating in the bent funnel _m_—the -tube _h_ having been previously removed, and the lower orifice of the -tube D either sunk to a considerable depth in mercury, or closed with a -ground stopper. The bend of the funnel _m_, may be accurately closed by -the introduction of a few lines of mercury. - -The application of the stop-cock _n_, has enabled Mr. Davy to perform -some experiments on respiration with considerable accuracy. - - _Note._ This apparatus was first described in - the third part of Dr. Beddoes’s Considerations; - its relation to Mr. Davy’s experiments with the - improvements it has lately received, may probably be - deemed sufficient to excuse the re-printing it.—The - weight I. Fig. 2, having been omitted in the plate, - the reader must supply the deficiency. - W. C. - - - - -PROPOSALS FOR THE PRESERVATION OF ACCIDENTAL OBSERVATIONS IN MEDICINE. - - -In times beyond the reach of history, the medicinal application of -substances could have arisen from no other source than accident. Among -articles of the materia medica of known origin, we are indebted to -accident for some of the most precious. - -Accident is every day presenting to different individuals the spectacle -of phænomena, arising from uncommon quantities of drugs on the one -hand, and on the other, from uncommon conditions of the system, where -ordinary powers only have been knowingly or recently applied. What is -said of drugs may be extended to natural agents and mental affections. - -From conversation with a variety both of medical practitioners and -unprofessional observers, the author of this proposal is persuaded -that such authentic occurrences only, as have presented themselves to -persons now living would, if they could be brought together, compose -a body of fact, so instructive to the philosopher, and useful to the -physician, that he despairs of finding a term worthy to characterize -it. - -In some cases, the influence of unsuspected powers would be detected. -In others, resources available to the purpose of restoring health in -desperate situations would be directly presented, or could be detected -by a short and easy process of reasoning. Some anomalous observations, -by shewing the absence or agency of contested causes, would perform -the office of _experimenta crucis_—Unusual affections occur of which -an exact account would be among the means of removing from physic its -opprobrious uncertainty: for this uncertainty frequently depends upon -our inability to distinguish the subtler differences in cases which -resemble each other in their grosser features. - -No striking fact can be accurately stated, in conjunction with its -antecedent and concomitant circumstances, without improving our -acquaintance with human nature. Our acquisitions in this most important -branch of knowledge, may be compared to a number of broken series, of -which we have not always more than one or two members. But every new -accession bids fair to fill up some deficiency; and a large supply -would contribute towards connecting series apparently independent, and -working up the whole into one grand all-comprehending chain. - -There are complaints, and those by far too frequent, where no known -process has a claim to the title of _remedial_. Here the whole chance -of preservation depends on the physician’s capacity for bringing -together facts that have heretofore stood remote. But no power of -combination can avail where there are no ideas to combine. - -Every new observation therefore, may be considered as a standard trunk, -sending forth analogies as so many branches crowned with blossoms, some -of which cannot fail to be succeeded by salutary fruits. And were it -not absurd to extend the illustration of so plain a point, it might -be added, that when by the continual interposition of new trunks, -the branches are brought near together, the produce of each will be -ennobled by the action of their respective principles of fecundation. - -Whenever the author has been able to obtain certain information -concerning any unusual appearance in animal nature, it has been his -custom to preserve it; and among his papers he has memorandums which -prove that to our present circumscribed ideas concerning the dose of -medicines may be sometimes imputed failures in practice; that certain -signs are not to be taken in the received signification; and that many -measures are adopted or omitted to the detriment of invalids, because -it is assumed that circumstances are necessarily connected which may -exist separately, or that one given natural operation is inconsistent -with another, to which it may really be synchronous or next in order. - -Assiduous observation of the daily states of the human microcosm will -be the unfailing consequence of attention to its striking phænomena. -Such is the progress of curiosity. Such the origin of all the sciences. -The more uniformly clear the sky under which they tended their flocks, -the less likely were the shepherds of Chaldæa, to found the science of -the stars. And however the disposition to study astronomy might have -been strengthened by the coincidence between the heliacal rising of -Sirius and the overflowing of the Nile, it must, I conceive, have been -awakened by the aspect of meteors and eclipses. - -Whatever minute and authentic information this imperfect statement -may produce, as soon as it shall amount to a certain mass, the author -will present it to the public arranged. He flatters himself that no -correspondent will eke out by supposition the defect of genuine -observation, without clearly distinguishing the one from the other. -He still more confidently hopes that none will be instigated by this -advertisement to exercise his invention in the manner of Psalmanasar -and Chatterton. Whether any literary forgery can be innocent is -questioned—but a forged medical report is a drawn dagger which the -arm of a credulous physician may any day plunge into the heart of his -defenceless patient. The author has heard some inconsiderate wits avow, -that they have transmitted to the venders of quack medicines imaginary -cures, attested by fictitious signatures; and it is not without -apprehension from the propensity of men to display ingenuity and to -relate wonders that he announces the present design. But he shall be on -his guard, and hopes to baffle attempts at imposition. - - THOMAS BEDDOES. - RODNEY-PLACE, Clifton, June 1800. - - -END. - - - - -ERRATA. - - - Page 19 line 15 for _is_ read _are_ - — 35 — 7 — for _principle_ read _principles_ - — 42 — 11 — for _take_ read _takes_ - — 68 Table 5 — for 5,88 read 15,88 - — 94 — 4 — for 1¹/₁₂ read ¹/₁₂. - — 95 — 4 — for 37 read 30,7 - — 96 — 3 — for 38 read ¹/₃₈ - — 105 — 9 — for _exactitude_ read _exactness_ - — 129 — 21 — for 41 read 4,1 - — 132 — 4 — for _into_ read _in_ - — 143 — 13 — for 25 read ,25 - — 186 — 15 — for _by_ read _from_ - — 208 last line — for _abstracted_ read _attracted_ - — 238 — 5 — for _gas_ read _oxide_ - — 259 — 4 — for 12 read 2 - — 283 — 4 — for _potash_ read _iron_ - — 315 — 14 — dele _in_ - — 409 — 15 — for _respiration_ read _expiration_ - — 464 — 10 — for _latter end_ read _end_ - — 543 — 3 — for _exhalation_ read _inhalation_. - - A few literal errors are left to the reader’s correction. - -N. B. The term ignited is sometimes used to signify any temperature -equal to or above a red heat, whether applied to solids, fluids, or -aëriform substances. - -The reasons for the use of the terms nitrogene and nitrous oxide, are -given in Mr. Nicholson’s Journal for January. - - - - - _Speedily will be Published_ - - OBSERVATIONS on the External and Internal Use of - NITROUS ACID. - - Demonstrating its PERMANENT EFFICACY in - VENEREAL COMPLAINTS; - - And extending its use to other dangerous - and painful Diseases. - - COMMUNICATED - By various Practitioners in EUROPE - and ASIA. - - TO - THOMAS BEDDOES, M. D. - - _Of the Publisher may be had, price 1s. 6d._ - - NOTICE of OBSERVATIONS - AT THE PNEUMATIC INSTITUTION, - _By THOMAS BEDDOES, M. D._ - - This Notice contains some trials of nitrous oxide by healthy - persons, not in the present work, and some cases of palsy - successfully treated by that gas. - - _Printed by Biggs and Cottle, St. Augustine’s Back._ - -*** END OF THE PROJECT GUTENBERG EBOOK RESEARCHES CHEMICAL AND -PHILOSOPHICAL *** - -Updated editions will replace the previous one--the old editions will -be renamed. - -Creating the works from print editions not protected by U.S. copyright -law means that no one owns a United States copyright in these works, -so the Foundation (and you!) can copy and distribute it in the -United States without permission and without paying copyright -royalties. Special rules, set forth in the General Terms of Use part -of this license, apply to copying and distributing Project -Gutenberg-tm electronic works to protect the PROJECT GUTENBERG-tm -concept and trademark. 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margin:1em 0'> -This eBook is for the use of anyone anywhere in the United States and -most other parts of the world at no cost and with almost no restrictions -whatsoever. You may copy it, give it away or re-use it under the terms -of the Project Gutenberg License included with this eBook or online -at <a href="https://www.gutenberg.org">www.gutenberg.org</a>. If you -are not located in the United States, you will have to check the laws of the -country where you are located before using this eBook. -</div> - -<p style='display:block; margin-top:1em; margin-bottom:0; margin-left:2em; text-indent:-2em'>Title: Researches Chemical and Philosophical</p> -<p style='display:block; margin-top:0; margin-bottom:1em; margin-left:2em; text-indent:0;'>Chiefly concerning nitrous oxide or dephlogisticated nitrous air and its respiration</p> - -<div style='display:block; margin-top:1em; margin-bottom:1em; margin-left:2em; text-indent:-2em'>Author: Humphry Davy</div> - -<div style='display:block; margin:1em 0'>Release Date: December 16, 2021 [eBook #66955]</div> - -<div style='display:block; margin:1em 0'>Language: English</div> - -<div style='display:block; margin:1em 0'>Character set encoding: UTF-8</div> - -<div style='display:block; margin-left:2em; text-indent:-2em'>Produced by: Tim Lindell and the Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive)</div> - -<div style='margin-top:2em; margin-bottom:4em'>*** START OF THE PROJECT GUTENBERG EBOOK RESEARCHES CHEMICAL AND PHILOSOPHICAL ***</div> - -<hr class="chap x-ebookmaker-drop" /> - -<h1>RESEARCHES,<br />CHEMICAL <span class="smcap">and</span> PHILOSOPHICAL;<br /> -<small>CHIEFLY CONCERNING</small><br /><big>NITROUS OXIDE,</big></h1> - -<p class="center">OR<br />DEPHLOGISTICATED NITROUS AIR,</p> -<p class="center">AND ITS<br />RESPIRATION.</p> - -<p class="f150 space-above2">By HUMPHRY DAVY,</p> - -<p class="center">SUPERINTENDENT OF THE MEDICAL PNEUMATIC<br />INSTITUTION.</p> -<p class="center space-above2">LONDON:</p> - -<p class="center">PRINTED FOR J. JOHNSON, ST. PAUL’S CHURCH-YARD,<br /> -BY BIGGS AND COTTLE, BRISTOL,<br />1800.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p class="f200 space-below2"><b>CONTENTS.</b></p> -</div> - -<table border="0" cellspacing="0" summary="TOC" cellpadding="0" > - <tbody><tr> - <td class="tdl" colspan="2"><span class="smcap">Introduction,</span></td> - <td class="tdr"><a href="#Page_xi">xi.</a></td> - </tr><tr> - <td class="tdc fontsize_150" colspan="3">RESEARCH I.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><i>Into the analysis of</i> <span class="smcap">Nitric Acid</span> - <i>and</i> <span class="smcap">Nitrous Gas</span>, - <i>and the production of</i> <span class="smcap">Nitrous Oxide</span>.</p></td> - </tr><tr> - <td class="tdc fontsize_120" colspan="3">DIVISION I.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><span class="smcap">Experiments</span> <i>and</i> <span class="smcap">Observations</span> - <i>on the composition of</i> <span class="smcap">Nitric Acid</span>, - <i>and on its combinations with</i> <span class="smcap">Water</span> - <i>and</i> <span class="smcap">Nitrous Gas</span>.</p></td> - </tr><tr> - <td class="tdr_top">1.</td> - <td class="tdl_ws1">Preliminaries</td> - <td class="tdr_bott"><a href="#RI_DI_01"> 1</a></td> - </tr><tr> - <td class="tdr_top">2.</td> - <td class="tdl_ws1">Production of aëriform Nitrous Acid</td> - <td class="tdr_bott"><a href="#RI_DI_02"> 3</a></td> - </tr><tr> - <td class="tdr_top">3.</td> - <td class="tdl_ws1">Specific gravity of Gases</td> - <td class="tdr_bott"><a href="#RI_DI_03"> 6</a></td> - </tr><tr> - <td class="tdr_top">4.</td> - <td class="tdl_ws1">Experiment on the formation of Nitrous Acid</td> - <td class="tdr_bott"><a href="#RI_DI_04">11</a></td> - </tr><tr> - <td class="tdr_top">5.</td> - <td class="tdl_ws1">Conclusions</td> - <td class="tdr_bott"><a href="#RI_DI_05">17</a></td> - </tr><tr> - <td class="tdr_top">6.</td> - <td class="tdl_ws1">Experiments on the combination of Nitrous Gas with Nitric Acid</td> - <td class="tdr_bott"><a href="#RI_DI_06">17</a></td> - </tr><tr> - <td class="tdr_top">7.</td> - <td class="tdl_ws1">Additional Experiments</td> - <td class="tdr_bott"><a href="#RI_DI_07">23</a></td> - </tr><tr> - <td class="tdr_top">8.</td> - <td class="tdl_ws1">Conclusions</td> - <td class="tdr_bott"><a href="#RI_DI_08">29</a></td> - </tr><tr> - <td class="tdr_top">9.</td> - <td class="tdl_ws1"><span class="smcap">Mr. Thomson’s</span> Theory of the difference - between Nitric and Nitrous Acid</td> - <td class="tdr_bott"><a href="#RI_DI_09">30</a></td> - </tr><tr> - <td class="tdr_top">10.</td> - <td class="tdl_ws1">Composition of the different Nitrous Acids</td> - <td class="tdr_bott"><a href="#RI_DI_10">36</a></td> - </tr><tr> - <td class="tdr_top">11.</td> - <td class="tdl_ws1">Combination of Nitric Acid with Water</td> - <td class="tdr_bott"><a href="#RI_DI_11">38</a></td> - </tr><tr> - <td class="tdr_top">12.</td> - <td class="tdl_ws1">Of Nitrous Vapor</td> - <td class="tdr_bott"><a href="#RI_DI_12">42</a></td> - </tr><tr> - <td class="tdr_top">13.</td> - <td class="tdl_ws1">Comparison of the results with those of Cavendish and Lavoisier</td> - <td class="tdr_bott"><a href="#RI_DI_13">43</a> - <span class="pagenum" id="Page_iv">[Pg iv]</span></td> - </tr><tr> - <td class="tdc_space-above2 fontsize_120" colspan="3">DIVISION II.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><span class="smcap">Experiments</span> <i>and</i> <span class="smcap">Observations</span> - <i>on the composition of</i> <span class="smcap">Ammoniac</span> <i>and on its combinations - with</i> <span class="smcap">Water</span> <i>and</i> <span class="smcap">Nitric Acid</span>.</p></td> - </tr><tr> - <td class="tdr_top">1.</td> - <td class="tdl_ws1">Analysis of Ammoniac</td> - <td class="tdr_bott"><a href="#RI_DII_01">56</a></td> - </tr><tr> - <td class="tdr_top">2.</td> - <td class="tdl_ws1">Specific gravity of Ammoniac</td> - <td class="tdr_bott"><a href="#RI_DII_02">62</a></td> - </tr><tr> - <td class="tdr_top">3.</td> - <td class="tdl_ws1">Of the quantities of true Ammoniac in Ammoniacal Solutions</td> - <td class="tdr_bott"><a href="#RI_DII_03">65</a></td> - </tr><tr> - <td class="tdr_top">4.</td> - <td class="tdl_ws1">Composition of Nitrate of Ammoniac</td> - <td class="tdr_bott"><a href="#RI_DII_04">71</a></td> - </tr><tr> - <td class="tdr_top">5.</td> - <td class="tdl_ws1">Decomposition of Carbonate of Ammoniac, by Nitrous Acid</td> - <td class="tdr_top"><a href="#RI_DII_05">75</a></td> - </tr><tr> - <td class="tdr_top">6.</td> - <td class="tdl_ws1">Decomposition of Sulphate of Ammoniac by Nitre</td> - <td class="tdr_bott"><a href="#RI_DII_06">77</a></td> - </tr><tr> - <td class="tdr_top">7.</td> - <td class="tdl_ws1">Non-existence of Ammoniacal Nitrites</td> - <td class="tdr_bott"><a href="#RI_DII_07">79</a></td> - </tr><tr> - <td class="tdr_top">8.</td> - <td class="tdl_ws1">Sources of error in Analysis</td> - <td class="tdr_bott"><a href="#RI_DII_08">80</a></td> - </tr><tr> - <td class="tdr_top">9.</td> - <td class="tdl_ws1">Loss in Solutions of Nitrate of Ammoniac during evaporation</td> - <td class="tdr_bott"><a href="#RI_DII_09">83</a></td> - </tr><tr> - <td class="tdc_space-above2 fontsize_120" colspan="3">DIVISION III.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><span class="smcap">Decomposition</span> <i>of</i> <span class="smcap">Nitrate</span> <i>of</i> - <span class="smcap">Ammoniac</span>—<i>Preparation - of</i> <span class="smcap">respirable Nitrous Oxide</span>.</p></td> - </tr><tr> - <td class="tdr_top">1.</td> - <td class="tdl_ws1">Of the heat required for the decomposition of Nitrate of Ammoniac</td> - <td class="tdr_bott"><a href="#RI_DIII_01">84</a></td> - </tr><tr> - <td class="tdr_top">2.</td> - <td class="tdl_ws1">Decomposition of Nitrate of Ammoniac—Production of respirable Nitrous Oxide—its properties</td> - <td class="tdr_bott"><a href="#RI_DIII_02">86</a></td> - </tr><tr> - <td class="tdr_top">3.</td> - <td class="tdl_ws1">Of the Gas remaining after the absorption of Nitrous Oxide by Water</td> - <td class="tdr_bott"><a href="#RI_DIII_03">89</a></td> - </tr><tr> - <td class="tdr_top">4.</td> - <td class="tdl_ws1">Specific Gravity of Nitrous Oxide</td> - <td class="tdr_bott"><a href="#RI_DIII_04">94</a></td> - </tr><tr> - <td class="tdr_top">5.</td> - <td class="tdl_ws1">Analysis of Nitrous Oxide</td> - <td class="tdr_bott"><a href="#RI_DIII_05">95</a></td> - </tr><tr> - <td class="tdr_top">6.</td> - <td class="tdl_ws1">Minute examination of the decomposition of Nitrate of Ammoniac</td> - <td class="tdr_bott"><a href="#RI_DIII_06">101</a></td> - </tr><tr> - <td class="tdr_top">7.</td> - <td class="tdl_ws1">Of the heat produced during the decomposition of Nitrate of Ammoniac</td> - <td class="tdr_bott"><a href="#RI_DIII_07">108</a> - <span class="pagenum" id="Page_v">[Pg v]</span></td> - </tr><tr> - <td class="tdr_top">8.</td> - <td class="tdl_ws1">Decomposition of Nitrate of Ammoniac at high temperatures</td> - <td class="tdr_bott"><a href="#RI_DIII_08">109</a></td> - </tr><tr> - <td class="tdr_top">9.</td> - <td class="tdl_ws1">Speculations on the decompositions of Nitrate of Ammoniac</td> - <td class="tdr_bott"><a href="#RI_DIII_09">113</a></td> - </tr><tr> - <td class="tdr_top">10.</td> - <td class="tdl_ws1">Of the preparation of Nitrous Oxide for experiments on respiration</td> - <td class="tdr_bott"><a href="#RI_DIII_10">117</a></td> - </tr><tr> - <td class="tdc_space-above2 fontsize_120" colspan="3">DIVISION IV.</td> - </tr><tr> - <td class="tdc" colspan="3"><span class="smcap">Experiments</span> <i>and</i> <span class="smcap">Observations</span> - <i>on the composition of</i><span class="smcap">Nitrous Gas</span>, - <i>and on its absorption by different bodies</i>.</td> - </tr><tr> - <td class="tdr_top">1.</td> - <td class="tdl_ws1">Preliminaries</td> - <td class="tdr_bott"><a href="#RI_DIV_01">122</a></td> - </tr><tr> - <td class="tdr_top">2.</td> - <td class="tdl_ws1">Analysis of Nitrous Gas by Charcoal</td> - <td class="tdr_bott"><a href="#RI_DIV_02">126</a></td> - </tr><tr> - <td class="tdr_top">3.</td> - <td class="tdl_ws1">Analysis of Nitrous Gas by Pyrophorus</td> - <td class="tdr_bott"><a href="#RI_DIV_03">132</a></td> - </tr><tr> - <td class="tdr_top">4.</td> - <td class="tdl_ws1">Additional observations on the composition of Nitrous Gas</td> - <td class="tdr_bott"><a href="#RI_DIV_04">134</a></td> - </tr><tr> - <td class="tdr_top">5.</td> - <td class="tdl_ws1">Absorption of Nitrous Gas by Water</td> - <td class="tdr_bott"><a href="#RI_DIV_05">140</a></td> - </tr><tr> - <td class="tdr_top">6.</td> - <td class="tdl_ws1">Absorption of Nitrous Gas by Water of different kinds</td> - <td class="tdr_bott"><a href="#RI_DIV_06">147</a></td> - </tr><tr> - <td class="tdr_top">7.</td> - <td class="tdl_ws1">Absorption of Nitrous Gas by solution of pale green Sulphate of Iron</td> - <td class="tdr_bott"><a href="#RI_DIV_07">152</a></td> - </tr><tr> - <td class="tdr_top">8.</td> - <td class="tdl_ws1">Absorption of Nitrous Gas by solution of green muriate of Iron</td> - <td class="tdr_bott"><a href="#RI_DIV_08">179</a></td> - </tr><tr> - <td class="tdr_top">9.</td> - <td class="tdl_ws1">By Solution of Nitrate of Iron</td> - <td class="tdr_bott"><a href="#RI_DIV_09">187</a></td> - </tr><tr> - <td class="tdr_top">10.</td> - <td class="tdl_ws1">By other metallic Solutions</td> - <td class="tdr_bott"><a href="#RI_DIV_10">189</a></td> - </tr><tr> - <td class="tdr_top">11.</td> - <td class="tdl_ws1">Action of sulphurated Hydrogene on solution - of green sulphate of iron impregnated with Nitrous Gas</td> - <td class="tdr_bott"><a href="#RI_DIV_11">191</a></td> - </tr><tr> - <td class="tdr_top">12.</td> - <td class="tdl_ws1">Additional Observations</td> - <td class="tdr_bott"><a href="#RI_DIV_12">193</a></td> - </tr><tr> - <td class="tdc_space-above2 fontsize_120" colspan="3">DIVISION V.</td> - </tr><tr> - <td class="tdc" colspan="3"><span class="smcap">Experiments</span> <i>and</i> <span class="smcap">Observations</span> <i>on the production of</i> - <span class="smcap">Nitrous Oxide</span> <i>from</i> <span class="smcap">Nitrous Gas</span> - <i>and</i> <span class="smcap">Nitric Acid</span> <i>in different modes</i>.</td> - </tr><tr> - <td class="tdr_top">1.</td> - <td class="tdl_ws1">Preliminaries</td> - <td class="tdr_bott"><a href="#RI_DV_01">197</a> - <span class="pagenum" id="Page_vi">[Pg vi]</span></td> - </tr><tr> - <td class="tdr_top">2.</td> - <td class="tdl_ws1">Conversion of Nitrous Gas into Nitrous Oxide by alkaline sulphites</td> - <td class="tdr_bott"><a href="#RI_DV_02">199</a></td> - </tr><tr> - <td class="tdr_top">3.</td> - <td class="tdl_ws1">By Muriate of Tin</td> - <td class="tdr_bott"><a href="#RI_DV_03">202</a></td> - </tr><tr> - <td class="tdr_top">4.</td> - <td class="tdl_ws1">By Sulphurated Hydrogene</td> - <td class="tdr_bott"><a href="#RI_DV_04">203</a></td> - </tr><tr> - <td class="tdr_top">5.</td> - <td class="tdl_ws1">Decomposition of Nitrous Gas by Nascent Hydrogene</td> - <td class="tdr_bott"><a href="#RI_DV_05">206</a></td> - </tr><tr> - <td class="tdr_top">6.</td> - <td class="tdl_ws1">Miscellaneous Observations</td> - <td class="tdr_bott"><a href="#RI_DV_06">209</a></td> - </tr><tr> - <td class="tdr_top">7.</td> - <td class="tdl_ws1">Recapitulation</td> - <td class="tdr_bott"><a href="#RI_DV_07">211</a></td> - </tr><tr> - <td class="tdr_top">8.</td> - <td class="tdl_ws1">Production of Nitrous Oxide from Metallic Solutions</td> - <td class="tdr_bott"><a href="#RI_DV_08">213</a></td> - </tr><tr> - <td class="tdr_top">9.</td> - <td class="tdl_ws1">Additional Observations relating to the production of Nitrous Oxide</td> - <td class="tdr_bott"><a href="#RI_DV_09">219</a></td> - </tr><tr> - <td class="tdr_top">10.</td> - <td class="tdl_ws1">Decomposition of Aqua regia by platina, - and evolution of a gas analogous to oxygenated muriatic acid, and nitrogene</td> - <td class="tdr_bott"><a href="#RI_DV_10">222</a></td> - </tr><tr> - <td class="tdr_top">11.</td> - <td class="tdl_ws1">Action of the electric spark on a mixture of Nitrogene and Nitrous gas</td> - <td class="tdr_bott"><a href="#RI_DV_11">229</a></td> - </tr><tr> - <td class="tdr_top">12.</td> - <td class="tdl_ws1">General remarks on the production of Nitrous Oxide</td> - <td class="tdr_bott"><a href="#RI_DV_12">231</a></td> - </tr><tr> - <td class="tdc_space-above2 fontsize_150" colspan="3">RESEARCH II.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><i>Into the combinations of</i> - <span class="smcap">Nitrous Oxide</span>, <i>and its decomposition</i>.</p></td> - </tr><tr> - <td class="tdc fontsize_120" colspan="3">DIVISION I.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><span class="smcap">Experiments</span> - <i>and</i> <span class="smcap">Observations</span> <i>on the combinations of</i> - <span class="smcap">Nitrous Oxide</span>.</p></td> - </tr><tr> - <td class="tdr_top">1.</td> - <td class="tdl_ws1">Combination of Water with Nitrous Oxide</td> - <td class="tdr_bott"><a href="#RII_DI_01">235</a></td> - </tr><tr> - <td class="tdr_top">2.</td> - <td class="tdl_ws1">—— of Nitrous Oxide with fluid inflammable bodies</td> - <td class="tdr_bott"><a href="#RII_DI_02">240</a></td> - </tr><tr> - <td class="tdr_top">3.</td> - <td class="tdl_ws1">Action of fluid Acids on Nitrous Oxide</td> - <td class="tdr_bott"><a href="#RII_DI_03">244</a></td> - </tr><tr> - <td class="tdr_top">4.</td> - <td class="tdl_ws1">—— of Saline Solutions</td> - <td class="tdr_bott"><a href="#RII_DI_04">245</a></td> - </tr><tr> - <td class="tdr_top">5.</td> - <td class="tdl_ws1">—— of Gases</td> - <td class="tdr_bott"><a href="#RII_DI_05">248</a></td> - </tr><tr> - <td class="tdr_top">6.</td> - <td class="tdl_ws1">Action of aëriform Nitrous Oxide on the alkalies—History of the - discovery of the combinations of Nitrous Oxide, with the alkalies</td> - <td class="tdr_bott"><a href="#RII_DI_06">254</a> - <span class="pagenum" id="Page_vii">[Pg vii]</span></td> - </tr><tr> - <td class="tdr_top">7.</td> - <td class="tdl_ws1">Combination of Nitrous Oxide with Potash</td> - <td class="tdr_bott"><a href="#RII_DI_07">262</a></td> - </tr><tr> - <td class="tdr_top">8.</td> - <td class="tdl_ws1">Combination of Nitrous Oxide with Soda</td> - <td class="tdr_bott"><a href="#RII_DI_08">268</a></td> - </tr><tr> - <td class="tdr_top">9.</td> - <td class="tdl_ws1">—— —— —— with Ammoniac</td> - <td class="tdr_bott"><a href="#RII_DI_09">269</a></td> - </tr><tr> - <td class="tdr_top">10.</td> - <td class="tdl_ws1">Probability of forming compounds of Nitrous Oxide and the alkaline earths</td> - <td class="tdr_bott"><a href="#RII_DI_10">273</a></td> - </tr><tr> - <td class="tdr_top">11.</td> - <td class="tdl_ws1">Additional Observations</td> - <td class="tdr_bott"><a href="#RII_DI_11">274</a></td> - </tr><tr> - <td class="tdr_top">12.</td> - <td class="tdl_ws1">The properties of Nitrous oxide resemble those of Acids</td> - <td class="tdr_bott"><a href="#RII_DI_12">276</a></td> - </tr><tr> - <td class="tdc_space-above2 fontsize_120" colspan="3">DIVISION II.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><i>Decomposition of</i> - <span class="smcap">Nitrous Oxide</span> <i>by combustible Bodies</i>.</p></td> - </tr><tr> - <td class="tdr_top">1.</td> - <td class="tdl_ws1">Preliminaries</td> - <td class="tdr_bott"><a href="#RII_DII_01">278</a></td> - </tr><tr> - <td class="tdr_top">2.</td> - <td class="tdl_ws1">Conversion of Nitrous Oxide into Nitrous Acid and a gas analogous - to Atmospheric Air by ignition</td> - <td class="tdr_bott"><a href="#RII_DII_02">279</a></td> - </tr><tr> - <td class="tdr_top">3.</td> - <td class="tdl_ws1">Decomposition of Nitrous Oxide by Hydrogene</td> - <td class="tdr_bott"><a href="#RII_DII_03">286</a></td> - </tr><tr> - <td class="tdr_top">4.</td> - <td class="tdl_ws1">—— —— —— by Phosphorus</td> - <td class="tdr_bott"><a href="#RII_DII_04">293</a></td> - </tr><tr> - <td class="tdr_top">5.</td> - <td class="tdl_ws1">—— —— by Phosphorated Hydrogene</td> - <td class="tdr_bott"><a href="#RII_DII_05">300</a></td> - </tr><tr> - <td class="tdr_top">6.</td> - <td class="tdl_ws1">—— by Sulphur</td> - <td class="tdr_bott"><a href="#RII_DII_06">303</a></td> - </tr><tr> - <td class="tdr_top">7.</td> - <td class="tdl_ws1">—— by Sulphurated Hydrogene</td> - <td class="tdr_bott"><a href="#RII_DII_07">306</a></td> - </tr><tr> - <td class="tdr_top">8.</td> - <td class="tdl_ws1">—— by Charcoal</td> - <td class="tdr_bott"><a href="#RII_DII_08">311</a></td> - </tr><tr> - <td class="tdr_top">9.</td> - <td class="tdl_ws1">—— by Hydrocarbonate</td> - <td class="tdr_bott"><a href="#RII_DII_09">313</a></td> - </tr><tr> - <td class="tdr_top">10.</td> - <td class="tdl_ws1"> Combustion of Iron in Nitrous Oxide</td> - <td class="tdr_bott"><a href="#RII_DII_10">316</a></td> - </tr><tr> - <td class="tdr_top">11.</td> - <td class="tdl_ws1">—— of Pyrophorus</td> - <td class="tdr_bott"><a href="#RII_DII_11">318</a></td> - </tr><tr> - <td class="tdr_top">12.</td> - <td class="tdl_ws1">—— of the Taper</td> - <td class="tdr_bott"><a href="#RII_DII_12">319</a></td> - </tr><tr> - <td class="tdr_top">13.</td> - <td class="tdl_ws1">—— of different Compound Bodies</td> - <td class="tdr_bott"><a href="#RII_DII_13">321</a></td> - </tr><tr> - <td class="tdr_top">14.</td> - <td class="tdl_ws1">General Conclusions relating to the decomposition of - Nitrous Oxide, and to its analysis</td> - <td class="tdr_bott"><a href="#RII_DII_14">322</a></td> - </tr><tr> - <td class="tdr_top">15.</td> - <td class="tdl_ws1">Observations on the combinations of Oxygene and Nitrogene</td> - <td class="tdr_bott"><a href="#RII_DII_15">325</a> - <span class="pagenum" id="Page_viii">[Pg viii]</span></td> - </tr><tr> - <td class="tdc_space-above2 fontsize_150" colspan="3">RESEARCH III.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><i>Relating to the</i> <span class="smcap">Respiration</span> <i>of</i> - <span class="smcap">Nitrous Oxide</span> <i>and</i> <span class="smcap">other Gases</span>.</p></td> - </tr><tr> - <td class="tdc fontsize_120" colspan="3">DIVISION I.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><span class="smcap">Experiments</span> <i>and</i> <span class="smcap">Observations</span> <i>on the - effects produced upon Animals by the respiration of</i> <span class="smcap">Nitrous Oxide</span>.</p></td> - </tr><tr> - <td class="tdr_top">1.</td> - <td class="tdl_ws1">Preliminaries</td> - <td class="tdr_bott"><a href="#RIII_DI_01">333</a></td> - </tr><tr> - <td class="tdr_top">2.</td> - <td class="tdl_ws1">On the respiration of Nitrous Oxide by warm-blooded Animals</td> - <td class="tdr_bott"><a href="#RIII_DI_02">336</a></td> - </tr><tr> - <td class="tdr_top">3.</td> - <td class="tdl_ws1">Effects of the respiration of Nitrous Oxide upon Animals, as compared - with those produced by their immersion in Hydrogene and Water</td> - <td class="tdr_bott"><a href="#RIII_DI_03">343</a></td> - </tr><tr> - <td class="tdr_top">4.</td> - <td class="tdl_ws1">Of the changes effected in the organisation of warm-blooded Animals, - by the respiration of Nitrous Oxide</td> - <td class="tdr_bott"><a href="#RIII_DI_04">347</a></td> - </tr><tr> - <td class="tdr_top">5.</td> - <td class="tdl_ws1">Of the respiration of mixtures of Nitrous Oxide and other Gases, - by warm-blooded Animals</td> - <td class="tdr_bott"><a href="#RIII_DI_05">358</a></td> - </tr><tr> - <td class="tdr_top">6.</td> - <td class="tdl_ws1">Recapitulation of facts relating to the respiration of Nitrous Oxide, - by warm-blooded Animals</td> - <td class="tdr_bott"><a href="#RIII_DI_06">360</a></td> - </tr><tr> - <td class="tdr_top">7.</td> - <td class="tdl_ws1">Of the respiration of Nitrous Oxide, by amphibious Animals</td> - <td class="tdr_bott"><a href="#RIII_DI_07">362</a></td> - </tr><tr> - <td class="tdr_top">8.</td> - <td class="tdl_ws1">Effects of Solution of Nitrous Oxide on Fishes</td> - <td class="tdr_bott"><a href="#RIII_DI_08">366</a></td> - </tr><tr> - <td class="tdr_top">9.</td> - <td class="tdl_ws1">Effects of Nitrous Oxide on Insects</td> - <td class="tdr_bott"><a href="#RIII_DI_09">370</a></td> - </tr><tr> - <td class="tdc_space-above2 fontsize_120" colspan="3">DIVISION II.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><i>Of the changes effected in</i> - <span class="smcap">Nitrous Oxide</span> <i>and other Gases, by the Respiration of Animals</i>.</p></td> - </tr><tr> - <td class="tdr_top">1.</td> - <td class="tdl_ws1">Preliminaries</td> - <td class="tdr_bott"><a href="#RIII_DII_01">373</a></td> - </tr><tr> - <td class="tdr_top">2.</td> - <td class="tdl_ws1">Absorption of Nitrous Oxide by Venous Blood</td> - <td class="tdr_bott"><a href="#RIII_DII_02">374</a></td> - </tr><tr> - <td class="tdr_top">3.</td> - <td class="tdl_ws1">Of the changes effected in Nitrous Oxide by Respiration</td> - <td class="tdr_bott"><a href="#RIII_DII_03">388</a></td> - </tr><tr> - <td class="tdr_top">4.</td> - <td class="tdl_ws1">Respiration of Hydrogene</td> - <td class="tdr_bott"><a href="#RIII_DII_04">400</a></td> - </tr><tr> - <td class="tdr_top">5.</td> - <td class="tdl_ws1">Additional Observations and Experiments on the Respiration of Nitrous Oxide</td> - <td class="tdr_bott"><a href="#RIII_DII_05">411</a> - <span class="pagenum" id="Page_ix">[Pg ix]</span></td> - </tr><tr> - <td class="tdr_top">6.</td> - <td class="tdl_ws1">Of the Respiration of Atmospheric Air</td> - <td class="tdr_bott"><a href="#RIII_DII_06">429</a></td> - </tr><tr> - <td class="tdr_top">7.</td> - <td class="tdl_ws1">Respiration of Oxygene</td> - <td class="tdr_bott"><a href="#RIII_DII_07">439</a></td> - </tr><tr> - <td class="tdr_top">8.</td> - <td class="tdl_ws1">Observations on the changes effected in the blood by Atmospheric Air and Oxygene</td> - <td class="tdr_bott"><a href="#RIII_DII_08">445</a></td> - </tr><tr> - <td class="tdr_top">9.</td> - <td class="tdl_ws1">Observations on the Respiration of Nitrous Oxide</td> - <td class="tdr_bott"><a href="#RIII_DII_09">449</a></td> - </tr><tr> - <td class="tdc_space-above2 fontsize_150" colspan="3">RESEARCH IV.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><i>Relating to the</i> <span class="smcap">Effects</span> <i>produced by the</i> - <span class="smcap">Respiration</span> <i>of</i> <span class="smcap">Nitrous Oxide</span> - <i>upon different</i> <span class="smcap">Individuals</span>.</p></td> - </tr><tr> - <td class="tdc fontsize_120" colspan="3">DIVISION I.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><span class="smcap">History</span> <i>of the Discovery</i>.—<span class="smcap">Effects</span> - <i>produced by the Respiration of different</i> <span class="smcap">Gases</span>.</p></td> - </tr><tr> - <td class="tdr_top">1.</td> - <td class="tdl_ws1">Respirability of Nitrous Oxide</td> - <td class="tdr_bott"><a href="#RIV_DI_01">456</a></td> - </tr><tr> - <td class="tdr_top">2.</td> - <td class="tdl_ws1">Effects of Nitrous Oxide</td> - <td class="tdr_bott"><a href="#RIV_DI_02">458</a></td> - </tr><tr> - <td class="tdr_top">3.</td> - <td class="tdl_ws1">General Effects of Nitrous Oxide on the Health</td> - <td class="tdr_bott"><a href="#RIV_DI_03">464</a></td> - </tr><tr> - <td class="tdr_top">4.</td> - <td class="tdl_ws1">Respiration of Hydrogene</td> - <td class="tdr_bott"><a href="#RIV_DI_04">466</a></td> - </tr><tr> - <td class="tdr_top">5.</td> - <td class="tdl_ws1">—— of Nitrogene</td> - <td class="tdr_bott"><a href="#RIV_DI_05">467</a></td> - </tr><tr> - <td class="tdr_top">6.</td> - <td class="tdl_ws1">Effects of Hydrocarbonate</td> - <td class="tdr_bott"><a href="#RIV_DI_06">468</a></td> - </tr><tr> - <td class="tdr_top">7.</td> - <td class="tdl_ws1">—— of Carbonic Acid</td> - <td class="tdr_bott"><a href="#RIV_DI_07">472</a></td> - </tr><tr> - <td class="tdr_top">8.</td> - <td class="tdl_ws1">—— of Oxygene</td> - <td class="tdr_bott"><a href="#RIV_DI_08">473</a></td> - </tr><tr> - <td class="tdr_top">9.</td> - <td class="tdl_ws1">—— of Nitrous Gas</td> - <td class="tdr_bott"><a href="#RIV_DI_09">475</a></td> - </tr><tr> - <td class="tdr_top">10.</td> - <td class="tdl_ws1">Most extensive action of Nitrous Oxide produces no debility</td> - <td class="tdr_bott"><a href="#RIV_DI_10">485</a></td> - </tr><tr> - <td class="tdc_space-above2 fontsize_120" colspan="3">DIVISION II.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><span class="smcap">Details</span> <i>of the Effects produced by the - Respiration of</i> <span class="smcap">Nitrous Oxide</span> <i>upon different - Individuals, furnished by Themselves</i>.</p></td> - </tr><tr> - <td class="tdr_top">1.</td> - <td class="tdl_ws1">Detail of Mr. J. W. Tobin</td> - <td class="tdr_bott"><a href="#RIV_DII_01">497</a></td> - </tr><tr> - <td class="tdr_top">2.</td> - <td class="tdl_ws1">—— of Mr. W. Clayfield</td> - <td class="tdr_bott"><a href="#RIV_DII_02">502</a></td> - </tr><tr> - <td class="tdr_top">3.</td> - <td class="tdl_ws1">Letter from Dr. Kinglake</td> - <td class="tdr_bott"><a href="#RIV_DII_03">503</a> - <span class="pagenum" id="Page_x">[Pg x]</span></td> - </tr><tr> - <td class="tdr_top">4.</td> - <td class="tdl_ws1">Detail of Mr. Southey</td> - <td class="tdr_bott"><a href="#RIV_DII_04">507</a></td> - </tr><tr> - <td class="tdr_top">5.</td> - <td class="tdl_ws1">Letter from Dr. Roget</td> - <td class="tdr_bott"><a href="#RIV_DII_05">509</a></td> - </tr><tr> - <td class="tdr_top">6.</td> - <td class="tdl_ws1">Letter from Mr. James Thomson</td> - <td class="tdr_bott"><a href="#RIV_DII_06">512</a></td> - </tr><tr> - <td class="tdr_top">7.</td> - <td class="tdl_ws1">Detail of Mr. Coleridge</td> - <td class="tdr_bott"><a href="#RIV_DII_07">516</a></td> - </tr><tr> - <td class="tdr_top">8.</td> - <td class="tdl_ws1">—— of Mr. Wedgwood</td> - <td class="tdr_bott"><a href="#RIV_DII_08">518</a></td> - </tr><tr> - <td class="tdr_top">9.</td> - <td class="tdl_ws1">—— of Mr. G. Burnet</td> - <td class="tdr_bott"><a href="#RIV_DII_09">520</a></td> - </tr><tr> - <td class="tdr_top">10.</td> - <td class="tdl_ws1">—— of Mr. T. Pople</td> - <td class="tdr_bott"><a href="#RIV_DII_10">521</a></td> - </tr><tr> - <td class="tdr_top">11.</td> - <td class="tdl_ws1">—— of Mr. Hammick</td> - <td class="tdr_bott"><a href="#RIV_DII_11">522</a></td> - </tr><tr> - <td class="tdr_top">12.</td> - <td class="tdl_ws1">—— of Dr. Blake</td> - <td class="tdr_bott"><a href="#RIV_DII_12">524</a></td> - </tr><tr> - <td class="tdr_top">13.</td> - <td class="tdl_ws1">—— of Mr. Wanfey</td> - <td class="tdr_bott"><a href="#RIV_DII_13">525</a></td> - </tr><tr> - <td class="tdr_top">14.</td> - <td class="tdl_ws1">—— of Mr. Rickman</td> - <td class="tdr_bott"><a href="#RIV_DII_14">526</a></td> - </tr><tr> - <td class="tdr_top">15.</td> - <td class="tdl_ws1">—— of Mr. Lovell Edgworth</td> - <td class="tdr_bott"><a href="#RIV_DII_15">527</a></td> - </tr><tr> - <td class="tdr_top">16.</td> - <td class="tdl_ws1">—— of Mr. G. Bedford</td> - <td class="tdr_bott"><a href="#RIV_DII_16">528</a></td> - </tr><tr> - <td class="tdr_top">17.</td> - <td class="tdl_ws1">—— of Miss Ryland</td> - <td class="tdr_bott"><a href="#RIV_DII_17">530</a></td> - </tr><tr> - <td class="tdr_top">18.</td> - <td class="tdl_ws1">Letter from Mr. M. M. Coates</td> - <td class="tdr_bott"><a href="#RIV_DII_18">530</a></td> - </tr><tr> - <td class="tdc_space-above2 fontsize_120" colspan="3">DIVISION III.</td> - </tr><tr> - <td class="tdc" colspan="3"><p class="neg-indent"><i>Abstracts from additional Details—Observations on - the effects of</i> <span class="smcap">Nitrous Oxide</span>, - <i>by</i> <span class="smcap">Dr. Beddoes</span>—<i>Conclusion</i>.</p></td> - </tr><tr> - <td class="tdr_top">1.</td> - <td class="tdl_ws1">Abstracts from additional details</td> - <td class="tdr_bott"><a href="#RIV_DIII_01">533</a></td> - </tr><tr> - <td class="tdr_top">2.</td> - <td class="tdl_ws1">Of the effects of Nitrous Oxide on delicate females</td> - <td class="tdr_bott"><a href="#RIV_DIII_02">537</a></td> - </tr><tr> - <td class="tdr_top">3.</td> - <td class="tdl_ws1">Observations on the effects of Nitrous Oxide by - <span class="smcap">Dr. Beddoes</span></td> - <td class="tdr_bott"><a href="#RIV_DIII_03">541</a></td> - </tr><tr> - <td class="tdr_top">4.</td> - <td class="tdl_ws1">Conclusion</td> - <td class="tdr_bott"><a href="#RIV_DIII_04">548</a></td> - </tr><tr> - <td class="tdc_space-above2 fontsize_150" colspan="3">APPENDIX.</td> - </tr><tr> - <td class="tdl_top">No. I.</td> - <td class="tdl_ws1">Of the effects of Nitrous Oxide on Vegetables</td> - <td class="tdr_bott"><a href="#APP_I">561</a></td> - </tr><tr> - <td class="tdl_top">No. II.</td> - <td class="tdl_ws1">Table of the Weight and Composition of the combinations of Nitrogene</td> - <td class="tdr_bott"><a href="#APP_II">566</a></td> - </tr><tr> - <td class="tdl_top">No. III.</td> - <td class="tdl_ws1">Additional Observations</td> - <td class="tdr_bott"><a href="#APP_III">567</a></td> - </tr><tr> - <td class="tdl_top">No. IV.</td> - <td class="tdl_ws1">Description of a Mercurial Airholder, and Breathing Machine, - by Mr. <span class="smcap">W. Clayfield</span>. </td> - <td class="tdr_bott"><a href="#APP_IV">573</a></td> - </tr><tr> - <td class="tdl_top">No. V.</td> - <td class="tdl_ws1">Proposals for the Preservation of Accidental Observations - in Medicine. By Dr. <span class="smcap">Beddoes</span>.</td> - <td class="tdr_bott"><a href="#APP_V">577</a></td> - </tr> - </tbody> -</table> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_xi">[Pg xi]</span></p> -<h2 class="nobreak" >INTRODUCTION.</h2> -</div> - -<p class="drop-cap"><span class="smcap">In</span> consequence of the discovery of the -respirability and extraordinary effects of nitrous oxide, or the dephlogisticated nitrous -gas of Dr. Priestley, made in April 1799, in a manner to be particularly described -hereafter,<a id="FNanchor_1" href="#Footnote_1" class="fnanchor">[1]</a> -I was induced to carry on the following investigation concerning its -composition, properties, combinations, and mode of operation on living beings.</p> - -<p>In the course of this investigation, I have met with many difficulties; -some arising from the novel and obscure nature of the subject, and -<span class="pagenum" id="Page_xii">[Pg xii]</span> -others from a want of coincidence in the observations of different -experimentalists on the properties and mode of production of the gas. -By extending my researches to the different substances connected -with nitrous oxide; nitrous acid, nitrous gas and ammoniac; and by -multiplying the comparisons of facts, I have succeeded in removing the -greater number of those difficulties, and have been enabled to give a -tolerably clear history of the combinations of oxygene and nitrogene.</p> - -<p>By employing both analysis and synthesis whenever these methods were -equally applicable, and comparing experiments made under different -circumstances, I have endeavoured to guard against sources of error; -but I cannot flatter myself that I have altogether avoided them. The -physical sciences are almost wholly dependant on the minute observation -and comparison of properties of things not immediately obvious to the -senses; and from the difficulty of discovering every possible mode of -<span class="pagenum" id="Page_xiii">[Pg xiii]</span> -examination, and from the modification of perceptions by the state -of feeling, it appears nearly impossible that all the relations of -a series of phænomena can be discovered by a single investigation, -particularly when these relations are complicated, and many of the -agents unknown. Fortunately for the active and progressive nature -of the human mind, even experimental research is only a method of -approximation to truth.</p> - -<p>In the arrangement of facts, I have been guided as much as possible by -obvious and simple analogies only. Hence I have seldom entered into -theoretical discussions, particularly concerning light, heat, and other -agents, which are known only by isolated effects.</p> - -<p>Early experience has taught me the folly of hasty generalisation. We -are ignorant of the laws of corpuscular motion; and an immense mass of -minute observations concerning the more complicated chemical changes -must be collected, probably before we shall be able to ascertain even -whether we are capable of discovering them. Chemistry in its present -<span class="pagenum" id="Page_xiv">[Pg xiv]</span> -state, is simply a partial history of phænomena, consisting of many -series more or less extensive of accurately connected facts.</p> - -<p>With the most important of these series, the arrangement of the -combinations of oxygene or the antiphlogistic theory discovered by -Lavoisier, the chemical details in this work are capable of being -connected.</p> - -<p>In the present state of science, it will be unnecessary to enter into -discussions concerning the importance of investigations relating to -the properties of physiological agents, and the changes effected in -them during their operation. By means of such investigations, we arrive -nearer towards that point from which we shall be able to view what is -within the reach of discovery, and what must for ever remain unknown to -us, in the phænomena of organic life. They are of immediate utility, by -enabling us to extend our analogies so as to investigate the properties -of untried substances, with greater accuracy and probability of success. -<span class="pagenum" id="Page_xv">[Pg xv]</span></p> - -<p>The <a href="#RES_I">first Research</a> in this work chiefly relates to the -production of nitrous oxide and the analysis of nitrous gas and nitrous acid. -In this there is little that can be properly called mine; and if by -repeating the experiments of other chemists, I have sometimes been able -to make more minute observations concerning phænomena, and to draw -different conclusions, it is wholly owing to the use I have made of -the instruments of investigation discovered by the illustrious fathers -of chemical philosophy,<a id="FNanchor_2" href="#Footnote_2" class="fnanchor">[2]</a> -and so successfully applied by them to the discovery of truth.</p> - -<p>In the <a href="#RES_II">second Research</a> the combinations and composition -of nitrous oxide are investigated, and an account given of its decomposition -by most of the combustible bodies.</p> - -<p>The <a href="#RES_III">third Research</a> contains observations on the action -<span class="pagenum" id="Page_xvi">[Pg xvi]</span> -of nitrous oxide upon animals, and an investigation of the changes effected -in it by respiration.</p> - -<p>In the <a href="#RES_IV">fourth Research</a> the history of the respirability -and extraordinary effects of nitrous oxide is given, with details of -experiments on its powers made by different individuals.</p> - -<p>I cannot close this introduction, without acknowledging my obligations -to Dr. Beddoes. In the conception of many of the following experiments, -I have been aided by his conversation and advice. They were executed -in an Institution which owes its existence to his benevolent and -philosophic exertions.</p> - -<p class="big-indent"><i>Dowry-Square, Hotwells, Bristol.</i><br /> -<span class="ws4"><i>June 25th, 1800.</i></span></p> - -<hr class="chap x-ebookmaker-drop" /> -<p class="f200"><b>RESEARCH I.</b></p> - -<p class="center"><span class="smcap">concerning the analysis of</span><br /> -<span class="fontsize_150">NITRIC ACID</span> <span class="smcap">and</span> -<span class="fontsize_150">NITROUS GAS</span></p> - -<p class="center"><span class="smcap">and the production of</span><br /> -<span class="fontsize_150">NITROUS OXIDE.</span></p> - -<hr class="chap x-ebookmaker-drop" /> -<div id="PLATE_1" class="figcenter"> - <p class="f150"><i>Pl. I.<br /> MERCURIAL AIRHOLDER and BREATHING MACHINE</i>.</p> - <img src="images/i_001.jpg" alt="" width="600" height="414" /> - <p class="author"><i>Lowry sculpᵗ.</i></p> -</div> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_1">[Pg 1]</span></p> -<h2 id="RES_I" class="nobreak">RESEARCH I.</h2> -</div> - -<p class="f120">INTO THE PRODUCTION AND ANALYSIS OF<br /> -<span class="fontsize_120"> NITROUS OXIDE,</span><br />AND THE AËRIFORM -FLUIDS RELATED TO IT.</p> - -<h3 id="RI_DIV_I">DIVISION I.</h3> - -<p class="neg-indent"><i>EXPERIMENTS and OBSERVATIONS on the composition of</i> -NITRIC ACID, <i>and on its combinations with</i> <span class="smcap">Water</span> -<i>and</i> <span class="smcap">Nitrous Gas</span>.</p> - -<p id="RI_DI_01">I. <span class="smcap"><b><big>T</big></b>hough</span> since -the commencement of Pneumatic Chemistry, no substance has been more the -subject of experiment than Nitrous Acid; yet still the greatest -uncertainty exists with regard to the quantities of the principles -entering into its composition.</p> - -<p>In comparing the experiments of the illustrious Cavendish on the -synthesis of nitrous acid, with those of Lavoisier on the decomposition -of nitre by charcoal, we find a much greater difference in the results -<span class="pagenum" id="Page_2">[Pg 2]</span> -than can be accounted for by supposing the acid formed, and that -decomposed, of different degrees of oxygenation.</p> - -<p>In the most accurate experiment of Cavendish, when the nitrous acid -appeared to be in a state of deoxygenation, 1 of nitrogene combined -with about 2,346 of oxygene.<a id="FNanchor_3" href="#Footnote_3" class="fnanchor">[3]</a> -In an earlier experiment, when the acid was probably fully oxygenated, -the nitrogene employed was to the oxygene nearly as 1 to 2,92.<a id="FNanchor_4" href="#Footnote_4" class="fnanchor">[4]</a></p> - -<p>Lavoisier, from his experiments on the decomposition of nitre, and -combination of nitrous gas and oxygene, concludes, that the perfectly -oxygenated, or what he calls nitric acid, is composed of nearly 1 -nitrogene, with 3,9 of oxygene; and the acid in the last state of -deoxygenation, or nitrous acid, of about 3 oxygene with 1 nitrogene.<a id="FNanchor_5" href="#Footnote_5" class="fnanchor">[5]</a></p> - -<p><span class="pagenum" id="Page_3">[Pg 3]</span> -Great as the difference is between the estimations of these -philosophers, we find differences still greater in the accounts of the -quantities of nitrous gas necessary to saturate a given quantity of -oxygene, as laid down by very accurate experimentalists. On the one -hand, Priestley found 1 of oxygene condensed by 2 of nitrous gas, and -Lavoisier by 1⅞. On the other, Ingenhouz, Scherer, and De la Metherie, -state the quantity necessary to be from 3 to 5.<a id="FNanchor_6" href="#Footnote_6" class="fnanchor">[6]</a> -Humbolt, who has lately investigated Eudiometry with great ingenuity, considers -the mean quantity of nitrous gas necessary to saturate 1 of oxygene, as about -2,55.<a id="FNanchor_7" href="#Footnote_7" class="fnanchor">[7]</a></p> - -<p id="RI_DI_02">II. To reconcile these different results is impossible, -and the immediate connection of the subject with the production of nitrous -oxide, as well as its general importance, obliged me to search for -<span class="pagenum" id="Page_4">[Pg 4]</span> -means of accurately determining the composition of nitrous acid in its -different degrees of oxygenation.</p> - -<p>The first desideratum was to ascertain the nature and composition of a -fluid acid, which by being deprived of, or combined with nitrous gas, -might become a standard of comparison for all other acids.</p> - -<p>To obtain this acid I should have preferred the immediate combination -of oxygene and nitrogene over water by the electric spark, had it -been possible to obtain in this way by a common apparatus sufficient -for extensive examination; but on carefully perusing the laborious -experiments of Cavendish, I gave up all thoughts of attempting it.</p> - -<p>My first experiments were made on the decomposition of nitre, -formed from a known quantity of pale nitrous acid of known specific -gravity, by phosphorus, tin, and charcoal: but in those processes, -unascertainable quantities of nitrous acid, with excess of nitrous gas, -always escaped undecompounded, and from the non-coincidence of results, -<span class="pagenum" id="Page_5">[Pg 5]</span> -where different quantities of combustible substances were employed, I -had reasons for believing that water was generally decomposed.</p> - -<p>Before these experiments were attempted, I had analized nitrous gas -and nitrous oxide, in a manner to be particularly described hereafter; -so that a knowledge of the quantities of nitrous gas and oxygene -entering into the composition of any acid, enabled me to determine the -proportions of nitrogene and oxygene it contained. In consequence of -which I attempted to combine together oxygene and nitrous gas, in such -a manner as to absorb the nitrous acid formed by water, in an apparatus -by which the quantities of the gases employed, and the increase of -weight of the water, might be ascertained; but this process likewise -failed. It was impossible to procure the gases perfectly free from -nitrogene, and during their combination, this nitrogene made to pass -into a pneumatic apparatus communicating with a vessel containing the -water carried over with it, much nitrous acid vapor, of different -composition from the acid absorbed. -<span class="pagenum" id="Page_6">[Pg 6]</span></p> - -<p>After many unsuccessful trials, Dr. Priestley’s experiments on nitrous -vapor<a id="FNanchor_8" href="#Footnote_8" class="fnanchor">[8]</a> -induced me to suppose that oxygene and nitrous gas, made to -combine out of the contact of bodies having affinity for oxygene, would -remain permanently aëriform, and on throwing them separately into an -exhausted glass balloon, I found that this was actually the case; -increase of temperature was produced, and orange colored nitrous acid -gas formed, which after remaining for many days in the globe, at a -temperature below 56°, did not in the slightest degree condense.</p> - -<p>This fact afforded me the means not only of forming a standard acid, -but likewise of ascertaining the specific gravity of nitrous acid in -its aëriform state.</p> - -<p id="RI_DI_03">III. Previous to the experiment, for the purpose of correcting -incidental errors, I was induced to ascertain the specific gravity of -<span class="pagenum" id="Page_7">[Pg 7]</span> -the gases employed, particularly as I was unacquainted with any process -by which the weight of nitrous gas had been accurately determined. Mr. -Kirwan’s estimation, which is generally adopted, being founded upon -the comparison of the loss of weight of a solution of copper in dilute -nitrous acid, with the quantity of gas produced.<a id="FNanchor_9" href="#Footnote_9" class="fnanchor">[9]</a></p> - -<p>The instruments that I made use of for containing and measuring my -gases, were two mercurial airholders graduated to the cubic inch of -Everard, and furnished with stop-cocks.<a id="FNanchor_10" href="#Footnote_10" class="fnanchor">[10]</a></p> - -<p><span class="pagenum" id="Page_8">[Pg 8]</span> -They were weighed in a glass globe, of the capacity of 108 cubic -inches, which with the small glass stop-cock affixed to it, was equal, -when filled with atmospheric air, to 1755 grains. The balance that I -employed, when loaded with a pound, turned with less than one eighth of -a grain.</p> - -<p>Into a mercurial airholder, of the capacity of 200 cubic inches, 160 -cubic inches of nitrous gas were thrown from a solution of mercury in -nitrous acid.</p> - -<p>70 measures of this were agitated for some minutes in a solution of -sulphate of iron,<a id="FNanchor_11" href="#Footnote_11" class="fnanchor">[11]</a> -till the diminution was complete. The nitrogene -remaining hardly filled a measure; and if we suppose with -Humbolt<a id="FNanchor_12" href="#Footnote_12" class="fnanchor">[12]</a> -that a very small portion of it was absorbed with the nitrous gas, the -whole quantity it contained may be estimated at 0,0142, or ¹/₇₀.</p> - -<p><span class="pagenum" id="Page_9">[Pg 9]</span> -75 cubic inches received from the airholder into an exhausted balloon, -increased it in weight 25,5 grains; thermometer being 56°, and -barometer 30,9. And allowing for the small quantity of nitrogene in the -gas, 100 cubic inches of it will weigh 34.3 grains.</p> - -<p>One hundred and thirty cubic inches of oxygene were procured from oxide -of manganese and sulphuric acid, by heat, and received in another -mercurial airholder.</p> - -<p>10 measures of it, mingled with 26 of the nitrous gas, gave, after -the residuum was exposed to solution of sulphate of iron, rather more -than one measure. Hence we may conclude that it contained about 0,1 nitrogene.</p> - -<p>60 cubic inches of it weighed 20,75 grains; and accounting for the -nitrogene contained in these, 100 grains of pure oxygene will weigh -35,09 grains.</p> - -<p>Atmospherical air was decomposed by nitrous gas in excess; and the -residuum washed with solution of sulphate of iron till the Nitrogene -remained pure; 87 cubic inches of it weighed 26,5 grains, thermometer -being 48°, barometer 30,1; 100 will consequently weigh 30,45. -<span class="pagenum" id="Page_10">[Pg 10]</span></p> - -<p>90 cubic inches of the air of the laboratory not deprived of its -carbonic acid, weighed 28,75 grains; thermometer 53, barometer 30: 100 -cubic inches will consequently weigh 31,9.<a id="FNanchor_13" href="#Footnote_13" class="fnanchor">[13]</a> -16 measures of this air, with 16 nitrous gas, of known composition, -diminished to 19. Hence it contained about,26 oxygene.<a id="FNanchor_14" href="#Footnote_14" class="fnanchor">[14]</a></p> - -<p>In comparing my results with those of Lavoisier and Kirwan, the -estimation of the weights of nitrogene and oxygene is very little -different, the corrections for temperature and pressure being made, -from that of those celebrated philosophers. The first makes oxygene to -weigh<a id="FNanchor_15" href="#Footnote_15" class="fnanchor">[15]</a> -34,21, and nitrogene 30,064 per cent; and the last, oxygene -34,<a id="FNanchor_16" href="#Footnote_16" class="fnanchor">[16]</a> and nitrogene 30,5.</p> - -<p><span class="pagenum" id="Page_11">[Pg 11]</span> -The specific gravity of nitrous gas, according to Kirwan, is to that of -common air as 1194 to 1000. Hence it should weigh about 37 grains per -cent. This difference from my estimation is not nearly so great as I -expected to have found it.<a id="FNanchor_17" href="#Footnote_17" class="fnanchor">[17]</a></p> - -<p id="RI_DI_04">IV.<a id="FNanchor_18" href="#Footnote_18" class="fnanchor">[18]</a> -The thermometer in the laboratory standing at 55°, and the -barometer at 30,1, I now proceeded to my experiment. The oxygene that -I employed was of the same composition as that which I had previously -weighed. The nitrous gas contained,0166 nitrogene.</p> - -<p>For the purpose of combining the gases, a glass balloon was procured, -of the capacity of 148 cubic inches, with a glass stop-cock adapted to -it, having its upper orifice tubulated and graduated for the purpose of -containing and measuring a fluid. The whole weight of this globe and -its appendages, when filled with common air, was 2066,5 grains. -<span class="pagenum" id="Page_12">[Pg 12]</span></p> - -<p>It was partially exhausted by the air-pump, and lost in weight just -32 grains. From whence we may conclude that about 15 grains of air -remained in it.</p> - -<p>In this state of exhaustion it was immediately cemented to the -stop-cock of the mercurial airholder, and the communication being made -with great caution, 82 cubic inches of nitrous gas rushed into the -globe, on the outside of which a slight increase of temperature was -perceived, while the gases on the inside appeared of a deep orange.</p> - -<p>Before the common temperature was restored, the communication was -stopped, and the globe removed. The increase of weight was 29,25 -grains; whence it appeared that 1,14 grains of common air, part of -which had been contained in the stop-cocks, had entered with the -nitrous gas.</p> - -<p>Whilst it was cooling, from the accidental loosening of the stopper of -the cock, 3 grains more of common air entered.<a id="FNanchor_19" href="#Footnote_19" class="fnanchor">[19]</a></p> - -<p><span class="pagenum" id="Page_13">[Pg 13]</span> -The communication was now made between the globe and the mercurial -airholder containing oxygene. 64 cubic inches were slowly pressed in, -when the outside of the globe became warmer, and the color on the -inside changed to a very dark orange. As it cooled, 6 cubic inches more -slowly entered; but no new increase of temperature, or change of color -took place.</p> - -<p>The globe being now completely cold, was stopped, removed, and weighed; -it had gained 24,5 grains, from whence it appears that 0,4 grains of -common air contained in the stop-cocks, had entered with the oxygene.<a id="FNanchor_20" href="#Footnote_20" class="fnanchor">[20]</a></p> - -<p>To absorb the nitrous acid gas, 41 grains of water were introduced by -the tube of the stop-cock, which though closed as rapidly as possible, -<span class="pagenum" id="Page_14">[Pg 14]</span> -must have suffered nearly,5 grains of air to enter at the same time, -as the increase of weight was 41,5 grains. The dark orange of the globe -diminished rapidly; it became warm at the bottom, and moist on the -sides. After a few minutes the color had almost wholly disappeared.</p> - -<p>To ascertain the quantity of aëriform fluid absorbed, the globe was -again attached to the mercurial air apparatus, containing 140 cubic -inches of common air. When the communication was made, 51 cubic inches -rushed in, and it gained in weight 16,5 grains.</p> - -<p>A quantity of fluid equal to 54 grains was now taken out of the globe. -On examination it proved to be slightly tinged with green, and occupied -a space equal to that filled by 41,5 grains of water. Its specific -gravity was consequently 1,301.</p> - -<p>To ascertain if any unabsorbed aëriform nitrous acid remained in the -globe, 13 grains of solution of ammonia were introduced in the same -manner as the water, and after some minutes, when the white vapor had -<span class="pagenum" id="Page_15">[Pg 15]</span> -condensed, the communication was again made with the mercurial -airholder containing common air. A minute quantity entered, which could -not be estimated at more than three fourths of an inch, and the globe -was increased in weight about 13,25 grains.<a id="FNanchor_21" href="#Footnote_21" class="fnanchor">[21]</a></p> - -<p>Common air was now thrown into the globe till the residual gases of -the experiment were judged to be displaced; it weighed 2106,5 grains, -that is, 40 grains more than it had weighed when filled with common air -before the experiment.<a id="FNanchor_22" href="#Footnote_22" class="fnanchor">[22]</a></p> - -<p><span class="pagenum" id="Page_16">[Pg 16]</span> -And if from those 40 grains we take 13 for the solution of ammonia -introduced, the remainder, 27, will be the quantity of solution of -nitrous acid in water remaining in the globe, which added to 54, equals -81 grains, the whole quantity formed; but if from this be taken 41 -grains, the quantity of water, the remainder 40 grains, will be the -quantity of nitrous acid gas absorbed in the solution.</p> - -<p>To find the absolute quantity of nitrous acid formed, we must find -the specific gravity of that absorbed; but as during, and after its -absorption, 17 grains of air, equal to 53,2 cubic inches entered, it -evidently filled such a space. 53,2 cubic inches of it consequently -weigh 40 grains, and 100 cubic inches 75,17 grains. Then,75 cubic -inches weigh,56 grains, and this added to 40, makes 40,56 grains, -equal to 53,95 cubic inches, the whole quantity of aëriform nitrous -acid produced.</p> - -<p>But the quantity of nitrous gas entering into this, allowing for the -<span class="pagenum" id="Page_17">[Pg 17]</span> -nitrogene it contained, is 27,6 grains, equal to about 80,5 cubic -inches; and the oxygene is 40,56-27,6 = to 12,96 grains, or 36,9 cubic -inches.</p> - -<p id="RI_DI_05">V. There could exist in this experiment no circumstance connected with -inaccuracy, except the impossibility of very minutely determining -the quantities of common air which entered with the gases from the -stop-cocks. But if errors have arisen from this source, they must be -very inconsiderable; as will appear from a calculation of the specific -gravity of the nitrous acid gas, founded on the volume of the gases -that entered the globe. -<span class="pagenum" id="Page_18">[Pg 18]</span></p> - -<table border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl" colspan="2">The air that remained in the globe</td> - <td class="tdr"> </td> - </tr><tr> - <td class="tdl"><span class="ws2">after exhaustion was 15 grains</span> - <span class="ws2">=</span></td> - <td class="tdl"> 47<a id="FNanchor_23" href="#Footnote_23" class="fnanchor">[23]</a></td> - <td class="tdr">cub. in.</td> - </tr><tr> - <td class="tdl">The nitrous gas introduced was</td> - <td class="tdl"> 82</td> - <td class="tdr"> </td> - </tr><tr> - <td class="tdl">Common air</td> - <td class="tdl"> 13</td> - <td class="tdr"> </td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdl"> 70</td> - <td class="tdr"> </td> - </tr><tr> - <td class="tdl">Common air</td> - <td class="tdl">  1</td> - <td class="tdr"> </td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdl">——</td> - <td class="tdr"> </td> - </tr><tr> - <td class="tdl">Whole quantity of air thrown into the globe </td> - <td class="tdl">213</td> - <td class="tdr"> </td> - </tr><tr> - <td class="tdl">From which subtract its capacity</td> - <td class="tdl">148</td> - <td class="tdr"> </td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdl">——</td> - <td class="tdr"> </td> - </tr><tr> - <td class="tdl">The remainder is</td> - <td class="tdl"> 65</td> - <td class="tdr"> </td> - </tr> - </tbody> -</table> - -<p class="no-indent">And this remainder taken from 80,5 nitrous gas + -36,9 oxygene, leaves 52,4 cubic inches, which is the space occupied by -the nitrous acid gas, and which differs from 53,95 only by 1,55 cubic -inches.</p> - -<p>I ought to have observed, that before this conclusive experiment, -two similar ones had been made. In comparing the results of one of -them, performed with the assistance of my friend, Mr. <span class="smcap">Joseph -Priestley</span>, Dr. <span class="smcap">Priestley’s</span> eldest son, and chiefly -detailed by him in the journal, I find a coincidence greater than could -be even well expected, where the processes are so complex. According to -that experiment, 41,5 grains of nitrous acid gas fill a space equal to -53 cubic inches, and are composed of nearly 29 nitrous gas, and 12,5 oxygene. -<span class="pagenum" id="Page_19">[Pg 19]</span></p> - -<p>We may then conclude, First, that 100 cubic inches of nitrous acid, -such as exists in the<a id="FNanchor_24" href="#Footnote_24" class="fnanchor">[24]</a> -aëriform state saturated with oxygene, at temperature 55°, and -atmospheric pressure 30,1 weigh 75,17 grains.</p> - -<p>Secondly, that 100 grains of it are composed of 68,06 nitrous gas, and -31,94 oxygene. Or assuming what will be hereafter proved, that 100 -parts of nitrous gas consist of 55,95 oxygene, and 44,05 nitrogene, of -29,9 nitrogene, and 70,1 oxygene; or taking away decimals, of 30 of the -one to 70 of the other.</p> - -<p>Thirdly, that 100 grains of pale green solution of nitrous acid in -water, of specific gravity 1,301, are composed of 50,62 water, and 49,38 -acid of the above composition.</p> - -<p id="RI_DI_06">VI. Having thus ascertained the composition of a standard acid, -my next object was to obtain it in a more condensed state, as it was otherwise -<span class="pagenum" id="Page_20">[Pg 20]</span> -impossible to saturate it to its full extent with nitrous gas. But this -I could effect in no other way than by comparing mixtures of known -quantities of water, and acids of different specific gravities and -colors, with the acid of 1,301.</p> - -<p>For the purpose of combining my acids with water, I made use of a -cylinder about 8 inches long, and,3 inches in diameter, accurately -graduated to grain measures, and furnished with a very tight stopper.</p> - -<p>The concentrated acid was first slowly poured into it, and the water -gradually added till the required specific gravity was produced;<a id="FNanchor_25" href="#Footnote_25" class="fnanchor">[25]</a> -the cylinder being closed and agitated after each addition, so as to -produce combination without any liberation of elastic fluid.</p> - -<p><span class="pagenum" id="Page_21">[Pg 21]</span> -After making a number of experiments with acids of different colors -in this advantageous way, I at length found that 90 grains of a deep -yellow acid, of specific gravity 1,5, became, when mingled at 40° with -77,5 grains of water, of specific gravity 1,302, and of a light green -tinge, as nearly as possible resembling that of the standard acid.</p> - -<p>Supposing, then, that these acids contain nearly the same relative -proportions of oxygene and nitrogene, 100 grains of the deep yellow -acid of 1,5, are composed of 91,9 grains true nitrous acid,<a id="FNanchor_26" href="#Footnote_26" class="fnanchor">[26]</a> -and 8,1 grains of water.</p> - -<p>To ascertain the difference between the composition of this acid, -and that of the pale, or nitric acid, of the same specific gravity, -I inserted 150 grains of it into a small cylindrical mattrass of the -capacity of,5 cubic inches, accurately graduated to grain measures, -<span class="pagenum" id="Page_22">[Pg 22]</span> -and connected by a curved tube with the water apparatus. After heat had -been applied to the bottom of the mattrass for a few minutes, the color -of the fluid gradually changed to a deep red, whilst the globules of -gas formed at the bottom of the acid, were almost wholly absorbed in -passing through it. In a short time deep red vapour began to fill the -tube, and being condensed by the water in the apparatus, was converted -into a bright green fluid, at the same time that minute globules of -gas were given out. As the heat applied became more intense, a very -singular phænomenon presented itself; the condensed vapor, increased -in quantity, at length filled the curvature of the tube, and when -expelled, formed itself into dark green spherules, which sunk to the -bottom of the water, rested for a moment, and then resolved themselves -into nitrous gas.<a id="FNanchor_27" href="#Footnote_27" class="fnanchor">[27]</a></p> - -<p>When the acid was become completely pale, it was suffered to cool, and -weighed. It had lost near 15 grains, and was of specific gravity 1,491. -<span class="pagenum" id="Page_23">[Pg 23]</span> -2 cubic inches and quarter of nitrous gas only were collected.</p> - -<p>From this experiment evidently no conclusions could be drawn, as the -nitrous gas had carried over with it much nitrous acid (in the form of -what Dr. Priestley calls nitrous vapor) and was partially dissolved -with it in the water.<a id="FNanchor_28" href="#Footnote_28" class="fnanchor">[28]</a></p> - -<p>To ascertain, then, the difference between the pale and yellow acids, I -was obliged to make use of synthesis, compared with analysis, carried -on in a different mode, by means of the following apparatus.</p> - -<p id="RI_DI_07">VII. To the stop-cock of the upper cylinder of the mercurial airholder, -a capillary tube was adapted, bent so as to be capable of introduction -into an orifice in the stopper of a graduated phial similar to that -employed for mingling acids with water, and sufficiently long to reach -the bottom. With another orifice in the stopper of the phial was -<span class="pagenum" id="Page_24">[Pg 24]</span> -connected a similar tube curved, for the purpose of containing a fluid, -and of increased diameter at the extremity.<a id="FNanchor_29" href="#Footnote_29" class="fnanchor">[29]</a></p> - -<p>50 cubic inches of pure nitrous gas<a id="FNanchor_30" href="#Footnote_30" class="fnanchor">[30]</a> -were thrown into the mercurial apparatus. The graduated phial, -containing 90 grains of nitric acid, of specific gravity 1,5, was -placed on the top of the airholding cylinder, and made to communicate -with it by means of the stop-cock and first tube. Into the second -tube a small quantity of solution of potash was placed. When all the -junctures were carefully cemented, by pressing on the airholder, the -nitrous gas was slowly passed into the phial, and absorbed by the -nitrous acid it contained; whilst the small quantities of nitrogene -evolved, slowly drove forward the solution in the curved tube; from the -height of which, as compared with that of the mercury in the conducing -tube, the pressure on the air in the cylinder was known. -<span class="pagenum" id="Page_25">[Pg 25]</span></p> - -<p>In proportion as the nitrous gas was absorbed, the phial became warm, -and the acid changed color; it first became straw-colored, then pale -yellow, and when about 7½ cubic inches had been combined with it, -bright yellow. It had gained in weight nearly 3 grains, and was become -of specific gravity 1,496.</p> - -<p>This experiment afforded me an approximation to the real difference -between nitric and yellow nitrous acid; and learning from it that -nitric acid was diminished in specific gravity by combination with -nitrous gas, I procured a pale acid of specific gravity 1,504.<a id="FNanchor_31" href="#Footnote_31" class="fnanchor">[31]</a> -After this acid had been combined in the same manner as before, with about 8 -cubic inches of nitrous gas,<a id="FNanchor_32" href="#Footnote_32" class="fnanchor">[32]</a> -it became nearly of specific gravity 1,5, and had gained in weight about 3 grains. -<span class="pagenum" id="Page_26">[Pg 26]</span></p> - -<p>Assuming the accuracy of this experiment as a foundation for -calculation, I endeavoured in the same manner to ascertain the -differences in the composition of the orange colored acids, and the -acids containing still larger proportions of nitrous gas.</p> - -<p>93 grains of the bright yellow acid of 1,5 became, when 6 cubic inches -of gas had been passed through it, orange colored and fuming, whilst -the undissolved gas increased in quantity so much as to render it -impossible to confine it by the solution of potash. When 9 cubic inches -had passed through, it became dark orange. It had gained in weight -2,75 grains, and was become of specific gravity 1,48 nearly. Hence it -was evident that much nitrous gas had passed through it undissolved. -25 cubic inches more of nitrous gas were now slowly sent through it: -it first became of a light olive, then of a dark olive, then of a -muddy green, then of a bright green, and lastly of a blue green. After -its assumption of this color, the gas appeared to pass through it -<span class="pagenum" id="Page_27">[Pg 27]</span> -unaltered, and large globules of fluid, of a darker green than the -rest, remained at the bottom of the cylinder, and when agitated, did -not combine with it. The increase of weight was only 1 grain, and the -acid was of specific gravity 1,474 nearly.</p> - -<p>In this experiment it was evident that the unabsorbed nitrous gas -had carried over with it a considerable quantity of nitrous acid. I -endeavoured to correct the errors resulting from this circumstance, -by connecting the curved tube first with a small water apparatus, and -afterwards with a mercurial apparatus; but when the water apparatus -was used, the greater part of the unabsorbed gas was dissolved with -the nitrous acid it held in solution, by the water; and when mercury -was employed, the nitrous acid that came over was decomposed, and the -quantity of nitrous gas evolved, in consequence increased.</p> - -<p>As it was possible that a small deficiency of weight might arise from -the red vapor given out during the processes of weighing and examining -<span class="pagenum" id="Page_28">[Pg 28]</span> -the acid in the last experiment, 35 cubic inches of nitrous gas were -very slowly passed through 90 grains of pale nitrous acid, of specific -gravity 1,5: it became of similar appearance to that just described, -had gained in weight 6,75 grains, and was become of specific gravity -1,475.</p> - -<p>These experiments did not afford approximations sufficiently accurate -towards the composition of deoxygenated acids, containing more nitrous -gas than the dark orange colored. To obtain them, a solution consisting -of 94,25 grains of blue green, or perfectly nitrated acid, (if we -may be allowed to employ the term), of specific gravity 1,475, was -inserted into a graduated phial, and connected by a curved tube, with -the mercurial airholder; in the conductor of which a small quantity of -water was inserted to absorb the nitrous acid which might be carried -over by the gas. Heat was slowly applied to the phial, and nitrous gas -given out with great rapidity. When 4 cubic inches were collected, the -<span class="pagenum" id="Page_29">[Pg 29]</span> -acid became dark olive, when 9 dark red, when 13 bright orange, and -when 18 pale. It had lost 31 grains, and when completely cool, was -of specific gravity 1,502 nearly. The water in the apparatus was -tinged of a light blue; from whence we may conclude that some of the -nitrous gas was absorbed by it with the nitrous acid: but it will be -hereafter proved that the orange colored acid is the most nitrated acid -capable of combining undecompounded with water, and that the color it -communicates to a large quantity of water, is light blue. If then we -take 6,1 grains, the quantity of gas collected, from 31 the loss, the -remainder is 24,9, which reasoning from the synthetical experiment, -may be supposed to contain nearly 3 cubic inches of nitrous gas. -Consequently, 94,25 grains of dark green acid, of specific gravity -1,475, are composed of nearly 21 cubic inches, or 7,2 grains of nitrous -gas, and 87,05 grains of pale nitrous acid, of 1,504.</p> - -<p id="RI_DI_08">VIII. Comparing the different synthetical and analytical experiments, -we may conclude with tolerable accuracy, that 92,75 grains of bright -<span class="pagenum" id="Page_30">[Pg 30]</span> -yellow, or standard acid of 1,5, are composed of 2,75 grains of nitrous -gas, and 90 grains of nitric acid of 1,504; but 92,75 grains of -standard acid contain 85,23 grains of nitrous acid, composed of about -27,23 of oxygene, and 58, nitrous gas: now from 58, take 2,75, and the -remainder 55,25, is the quantity of nitrous gas contained in 90 grains -of nitric acid of 1,504; consequently, 100 grains of it are composed -of 8,45 water, and 91,55 true acid, containing 61,32 nitrous gas, and -30,23 oxygene; or 27,01 nitrogene, and 64,54 oxygene: and the nitrogene -in nitric acid, is to the oxygene as 1 to 2,389.</p> - -<p id="RI_DI_09">IX. My ingenious friend, Mr. <span class="smcap">James Thomson</span>, -has communicated to me some observations relating to the composition of nitrous acid -(that is, the orange colored acid), from which he draws a conclusion -which is, in my opinion, countenanced by all the facts we are in -possession of, namely, “that it ought not to be considered as a -<span class="pagenum" id="Page_31">[Pg 31]</span> -distinct and less oxygenated state of acid, but simply as nitric or -pale acid, holding in solution, that is, loosely combined with, nitrous -gas.”<a id="FNanchor_33" href="#Footnote_33" class="fnanchor">[33]</a></p> - -<p><span class="pagenum" id="Page_32">[Pg 32]</span> -It is impossible to call any substance a simple acid that is incapable -of entering undecompounded into combination with the alkalies, &c; but -it will appear hereafter that the salts called in the new nomenclature -<i>nitrites</i>, cannot be directly formed. If, indeed, it could be -proved, that the heat produced by the combination of nitrous acid with -salifiable bases, was the only cause of the partial decomposition of -it, and that when this process was effected in such a way as to prevent -increase of temperature, no nitrous gas was liberated, the common theory -<span class="pagenum" id="Page_33">[Pg 33]</span> -might have some foundation; but though dilute phlogisticated nitrous -acid combines<a id="FNanchor_34" href="#Footnote_34" class="fnanchor">[34]</a> -with alkaline solutions without decomposition, yet no excess of nitrous -gas is found in the solid salt: it is either disengaged in proportion -as the water is evaporated, or it absorbs oxygene from the atmosphere, -and becomes nitric acid.</p> - -<p>In proportion as the nitrous acids contain more nitrous gas, so in -proportion do they more readily give it out. From the blue green acid -it is liberated slowly at the temperature of 50°, and from the green -likewise on agitation. The orange coloured and yellow acids do not -require a heat above 200° to free them of their nitrous gas; and all the -<span class="pagenum" id="Page_34">[Pg 34]</span> -colored acids, when exposed to the atmosphere absorb oxygene, and -become by degrees pale.</p> - -<p>If the nitrous vapour, i. e. such as is disengaged during the -<i>denitration</i> of the colored acids, was capable of combining -with the alkalies, it might be supposed a distinct acid, and called -nitrous acid; and the acids of different colors might be considered -simply as compounds of this acid with nitric acid; but it appears to be -nothing more than a solution of nitric acid in nitrous gas, incapable -of condensation, undecompounded, and when decompounded and condensed, -constituting the dark green acid, which is immiscible with water,<a id="FNanchor_35" href="#Footnote_35" class="fnanchor">[35]</a> -and uncombinable with the alkalies.<a id="FNanchor_36" href="#Footnote_36" class="fnanchor">[36]</a></p> - -<p>It seems therefore reasonable, till we are in possession of new lights -on the subject, to consider, with Mr. Thomson, the deoxygenated or -<span class="pagenum" id="Page_35">[Pg 35]</span> -nitrous acids simply as solutions of nitrous gas composed of sulphuric -acid, metallic oxides, and nitrous gas.<a id="FNanchor_37" href="#Footnote_37" class="fnanchor">[37]</a></p> - -<p>Supposing the truth of these principles according to the logic of the -French nomenclature, there is no acid to which the term nitrous acid -<i>ought</i> to be applied; but as it has been used to signify the -acids holding in solution nitrous gas, it is perhaps better still to -apply it to those substances, than to invent for them new names. A -nomenclature, accurately expressing their constituent parts, would be -too complex, and like all other nomenclatures founded upon theory, -liable to perpetual alterations. Their composition is known from their -specific gravity and their colors; hence it is better to denote it -by those physical properties: thus orange nitrous acid, of specific -<span class="pagenum" id="Page_36">[Pg 36]</span> -gravity 1,480, will signify a solution of nitrous gas in nitric acid, -in which the nitric acid is to the nitrous gas, nearly as 87 to 5, and -to the water as 11 to 1.</p> - -<p id="RI_DI_10">X. The estimation of the composition of the yellow and orange -colored nitrous acids given in the following table, may be considered as -tolerably accurate, being deduced from the synthetical experiments -in the sixth section, compared with the analytical ones. But as -in the synthetical experiment, when the acid became green, it was -impossible to ascertain the quantity of nitrous gas that passed through -it unabsorbed, and as in the analysis the quantity of nitrous gas -dissolved by the water at different periods of the experiment could not -be ascertained, the accounts of the composition of the green acids must -be considered only as very imperfect approximations to truth. -<span class="pagenum" id="Page_37">[Pg 37]</span></p> - -<p class="f150"><b>TABLE I.</b></p> - -<div class="blockquot2"> -<p class="center"><i>Containing Approximations to the quantities of -NITRIC ACID, NITROUS GAS, and WATER in NITROUS ACIDS, of different -colors and specific gravities.</i></p> -</div> - -<table border="0" cellspacing="0" summary=" " cellpadding="0" rules="cols" > - <thead><tr> - <th class="tdc bb" colspan="7"> </th> - </tr><tr> - <th class="tdc bb">100 Parts</th> - <th class="tdc bb"> </th> - <th class="tdc bb"> Specific <br />Gravity</th> - <th class="tdc bb"> </th> - <th class="tdc bb"> Nitric <br />Acid</th> - <th class="tdc bb"> Water </th> - <th class="tdc bb"> Nitrous<br />gas</th> - </tr> - </thead> - <tbody><tr> - <td class="tdl">Sol. Nitric Acid</td> - <td class="tdc"> </td> - <td class="tdc">1,504</td> - <td class="tdc"> c </td> - <td class="tdc">91,55</td> - <td class="tdc">8,45</td> - <td class="tdc">— —</td> - </tr><tr> - <td class="tdl">Yellow Nitrous<a id="FNanchor_38" href="#Footnote_38" class="fnanchor">[38]</a> </td> - <td class="tdc"> </td> - <td class="tdc">1,502</td> - <td class="tdc">o</td> - <td class="tdc">90,5 </td> - <td class="tdc">8,3 </td> - <td class="tdc">1,2 </td> - </tr><tr> - <td class="tdl">Bright Yellow</td> - <td class="tdc">  o  </td> - <td class="tdc">1,500</td> - <td class="tdc">n</td> - <td class="tdc">88,94</td> - <td class="tdc">8,10</td> - <td class="tdc">2,96</td> - </tr><tr> - <td class="tdl">Dark Orange</td> - <td class="tdc">f</td> - <td class="tdc">1,480</td> - <td class="tdc">t</td> - <td class="tdc">86,84</td> - <td class="tdc">7,6 </td> - <td class="tdc">5,56</td> - </tr><tr> - <td class="tdl">Light Olive‡</td> - <td class="tdc"> </td> - <td class="tdc">1,479</td> - <td class="tdc">a</td> - <td class="tdc">86,00</td> - <td class="tdc">7,55</td> - <td class="tdc">6,45</td> - </tr><tr> - <td class="tdl">Dark Olive‡</td> - <td class="tdc"> </td> - <td class="tdc">1,478</td> - <td class="tdc">i</td> - <td class="tdc">85,4 </td> - <td class="tdc">7,5 </td> - <td class="tdc">7,1 </td> - </tr><tr> - <td class="tdl">Bright Green‡</td> - <td class="tdc"> </td> - <td class="tdc">1,476</td> - <td class="tdc">n</td> - <td class="tdc">84,8 </td> - <td class="tdc">7,44</td> - <td class="tdc">7,76</td> - </tr><tr> - <td class="tdl">Blue Green<a id="FNanchor_39" href="#Footnote_39" class="fnanchor">[39]</a></td> - <td class="tdc"> </td> - <td class="tdc">1,475</td> - <td class="tdc"> </td> - <td class="tdc">84,6 </td> - <td class="tdc">7,4 </td> - <td class="tdc">8,00</td> - </tr><tr> - <td class="tdl bt" colspan="7">  ‡ = “FOOTNOTE [38]”</td> - </tr> - </tbody> -</table> -<p><span class="pagenum" id="Page_38">[Pg 38]</span></p> -<p class="f150 space-above2"><b>TABLE II.</b></p> - -<div class="blockquot2"> -<p class="center"><i>Binary Proportions of OXYGENE and NITROGENE in -NITRIC and NITROUS ACIDS.</i><a id="FNanchor_40" href="#Footnote_40" class="fnanchor">[40]</a></p> -</div> - -<table border="0" cellspacing="0" summary=" " cellpadding="0" rules="cols" > - <thead><tr> - <th class="tdc bb" colspan="7"> </th> - </tr><tr> - <th class="tdc bb">100 Parts</th> - <th class="tdc bb"> </th> - <th class="tdc bb"> Oxygene </th> - <th class="tdc bb"> Nitrogene </th> - <th class="tdc bb"> </th> - <th class="tdc bb"> Nitrogene </th> - <th class="tdc bb"> Oxygene </th> - </tr> - </thead> - <tbody><tr> - <td class="tdl">Nitric Acid</td> - <td class="tdc">c</td> - <td class="tdc">70,50</td> - <td class="tdc">29,50</td> - <td class="tdc"> </td> - <td class="tdc">1</td> - <td class="tdc">2,389</td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdc">o</td> - <td class="tdc"> </td> - <td class="tdc"> </td> - <td class="tdc"> </td> - <td class="tdc"> </td> - <td class="tdc"> </td> - </tr><tr> - <td class="tdl">Bright yellow Nitrous </td> - <td class="tdc">n</td> - <td class="tdc">70,10</td> - <td class="tdc">29,90</td> - <td class="tdc">Proportions.</td> - <td class="tdc">1</td> - <td class="tdc">2,344</td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdc">t</td> - <td class="tdc"> </td> - <td class="tdc"> </td> - <td class="tdc">Nitrogene.</td> - <td class="tdc"> </td> - <td class="tdc"> </td> - </tr><tr> - <td class="tdl">Orange coloured</td> - <td class="tdc">a</td> - <td class="tdc">69,63</td> - <td class="tdc">30,37</td> - <td class="tdc">Unity.</td> - <td class="tdc">1</td> - <td class="tdc">2,292</td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdc">i</td> - <td class="tdc"> </td> - <td class="tdc"> </td> - <td class="tdc"> </td> - <td class="tdc"> </td> - <td class="tdc"> </td> - </tr><tr> - <td class="tdl">Dark Green</td> - <td class="tdc">n</td> - <td class="tdc">69,08</td> - <td class="tdc">30,92</td> - <td class="tdc"> </td> - <td class="tdc">1</td> - <td class="tdc">2,230</td> - </tr><tr> - <td class="tdc bt" colspan="7"> </td> - </tr> - </tbody> -</table> - -<p id="RI_DI_11">XI. I have before mentioned that dilute nitric acids are incapable -of dissolving so much nitrous gas in proportion to their quantities of -true acid, as concentrated ones. During their absorption of it, they -go through similar changes of color; 330 grains of nitric acid, of -specific gravity 1,36, after 50 cubic inches of gas had been passed -<span class="pagenum" id="Page_39">[Pg 39]</span> -through it, became blue green, and of specific gravity 1,351. It had -gained in weight but 3 grains; and when the nitrous gas was driven from -it by heat into a water apparatus, but 7 cubic inches were collected.<a id="FNanchor_41" href="#Footnote_41" class="fnanchor">[41]</a></p> - -<p>From the diminution of specific gravity of nitric acid by combination -with nitrous gas, and from the smaller attraction of nitric acid for -nitrous gas, in proportion as it is diluted, it is probable that the -nitrated acids, in their combinations with water, do not contract so -much as<a id="FNanchor_42" href="#Footnote_42" class="fnanchor">[42]</a> -nitric acids of the same specific gravities. The affinities -resulting from the small attraction of nitrous gas for water, and its -greater attraction for nitric acid, must be such as to lessen the -affinity of nitric acid and water for each other.</p> - -<p>Hence it would require an infinite number of experiments to ascertain -the real quantities of acid, nitrous gas, and water, contained in the -<span class="pagenum" id="Page_40">[Pg 40]</span> -different diluted nitrous acids; and after these quantities were -determined, they would probably have no important connection with the -chemical arrangement. As yet, our instruments of experiment are not -sufficiently exact to afford us the means of ascertaining the ratio -in which the attraction of nitric acid<a id="FNanchor_43" href="#Footnote_43" class="fnanchor">[43]</a> -for water diminishes in its progress towards saturation.</p> - -<p>The estimations in the following table, of the real quantities of -nitric acid in solutions of different specific gravities, were deduced -from experiments made in the manner described in section VI, except -that the phial employed was longer, narrower, and graduated to half -grains. The temperature, at the time of combination, was from 40° to 46°. -<span class="pagenum" id="Page_41">[Pg 41]</span></p> - -<p class="f150 space-above2"><b>TABLE III.</b></p> - -<div class="blockquot2"> -<p class="center"><i>Of the Quantities of True NITRIC ACID in solutions -of different SPECIFIC GRAVITIES.</i></p> -</div> - -<table border="0" cellspacing="0" summary=" " cellpadding="0" rules="cols" > - <thead><tr> - <th class="tdc bb" colspan="4"> </th> - </tr><tr> - <th class="tdc bb">100 Parts Acid <br />of specific gravity </th> - <th class="tdc bb"> </th> - <th class="tdc bb"> True Acid<a id="FNanchor_44" href="#Footnote_44" class="fnanchor">[44]</a> </th> - <th class="tdc bb"> Water </th> - </tr> - </thead> - <tbody><tr> - <td class="tdc">1,5040</td> - <td class="tdc"> </td> - <td class="tdc">91,55</td> - <td class="tdc">8,45</td> - </tr><tr> - <td class="tdc">1,4475</td> - <td class="tdc">c</td> - <td class="tdc">80,39</td> - <td class="tdc">19,61</td> - </tr><tr> - <td class="tdc">1,4285</td> - <td class="tdc">o</td> - <td class="tdc">71,65</td> - <td class="tdc">28,35</td> - </tr><tr> - <td class="tdc">1,3906</td> - <td class="tdc">n</td> - <td class="tdc">62,96</td> - <td class="tdc">37,04</td> - </tr><tr> - <td class="tdc">1,3551</td> - <td class="tdc">t</td> - <td class="tdc">56,88</td> - <td class="tdc">43,12</td> - </tr><tr> - <td class="tdc">1,3186</td> - <td class="tdc">a</td> - <td class="tdc">52,03</td> - <td class="tdc">47,97</td> - </tr><tr> - <td class="tdc">1,3042</td> - <td class="tdc">i</td> - <td class="tdc">49,04</td> - <td class="tdc">50,96</td> - </tr><tr> - <td class="tdc">1,2831</td> - <td class="tdc">n</td> - <td class="tdc">46,03</td> - <td class="tdc">53,97</td> - </tr><tr> - <td class="tdc">1,2090</td> - <td class="tdc"> </td> - <td class="tdc">45,27</td> - <td class="tdc">54,73</td> - </tr><tr> - <td class="tdc bt" colspan="4"> </td> - </tr> - </tbody> -</table> - -<p id="RI_DI_12"><span class="pagenum" id="Page_42">[Pg 42]</span> -XII. The blue green spherules mentioned in section V. produced by -the condensation of nitrous vapor, and by the combination of nitric -acid with nitrous gas, may be considered as saturated solutions of -nitrous gas in nitric acid. The combinations of nitric acid and nitrous -gas containing a larger proportion of nitrous gas, are incapable of -existing in the fluid state at common temperatures; and, as appears -from the first experiment, an increase of volume takes place during -their formation. They consequently ought to be looked upon as solutions -of nitric acid in nitrous gas, identical with the nitrous vapor of -Priestley.</p> - -<p>From the researches of this great discoverer, we learn that nitrous -vapor is decomposable, both by water and mercury. Hence it is almost -impossible accurately to ascertain its composition. In one of his -experiments,<a id="FNanchor_45" href="#Footnote_45" class="fnanchor">[45]</a> -when more than 130 grains of strong nitrous acid were -<span class="pagenum" id="Page_43">[Pg 43]</span> -exposed for two days to nearly 247 cubic inches of nitrous gas, over -water: about half of the acid was dissolved, and deposited with the gas -in the water.<a id="FNanchor_46" href="#Footnote_46" class="fnanchor">[46]</a></p> - -<p id="RI_DI_13">XIII. In comparing the results of my fundamental experiment on the -composition of nitrous acid, with those of Cavendish, the great -coincidence between them gave me very high satisfaction, as affording -additional proofs of accuracy. If the acid formed in the last -experiment of this illustrious philosopher be supposed analogous to the -light green acid formed in my first experiment, our estimations will be -almost identical.</p> - -<p>Lavoisier’s account of the composition of the nitric and nitrous -acids, has been generally adopted. According to his estimation, these -substances contain a much larger quantity of oxygene than I have -assigned to them. -<span class="pagenum" id="Page_44">[Pg 44]</span></p> - -<p>The fundamental experiments of this great philosopher were made at an -early period of pneumatic chemistry,<a id="FNanchor_47" href="#Footnote_47" class="fnanchor">[47]</a> -on the decomposition of nitre by charcoal; and he considered the -nitrogene evolved, and the oxygene of the carbonic acid produced in -this process, as the component parts of the nitric acid contained in -the nitre.</p> - -<p>I have before mentioned the liberation of nitrous acid, in the -decomposition of nitre by combustible bodies; and I had reasons for -suspecting that this circumstance was not the only source of inaccuracy.</p> - -<p>That my suspicions were well founded, will appear from the following -experiments:</p> - -<p>EXPERIMENT <i>a</i>. I introduced into a strong glass tube, 3 inches -long, and nearly,3 wide, a mixture of 10 grains of pulverised, well -burnt charcoal, and 60 grains of nitre. It was fired by means of -touch-paper, and the tube instantly plunged under a jar filled with dry -<span class="pagenum" id="Page_45">[Pg 45]</span> -mercury. A quantity of gas, clouded with dense white vapor was -collected. When this vapor was precipitated, so that the surface of the -mercury could be seen, it appeared white, as if acted on by nitrous -acid. On introducing a little oxygene into the jar, copious red fumes -appeared.</p> - -<p>EXP. <i>b</i>. A similar mixture was fired<a id="FNanchor_48" href="#Footnote_48" class="fnanchor">[48]</a> -under the jar, the top of the mercury being covered with a small -quantity of red cabbage juice, rendered green by an alkali. This juice, -examined when the vapor was precipitated, was become red, and on -introducing to it a little carbonate of potash, a slight effervescence -took place.</p> - -<p>EXP. <i>c</i>. Five grains of charcoal, and 20 of nitre, were now fired -in the same manner as before, the mercury being covered with a stratum -<span class="pagenum" id="Page_46">[Pg 46]</span> -of water. After the precipitation of the vapor on the introduction of -oxygene, no red fumes were perceived.</p> - -<p>EXP. <i>d</i>. 30 grains of nitre, 5 of charcoal, and five of silicious -earth,<a id="FNanchor_49" href="#Footnote_49" class="fnanchor">[49]</a> -were now mingled and fired. The gas received under mercury -was composed of 18 carbonic acid, and nearly 12 nitrogene.<a id="FNanchor_50" href="#Footnote_50" class="fnanchor">[50]</a> -A little muriatic acid was poured on the residuum in the tube; a slight -effervescence took place.</p> - -<p>EXP. <i>e</i>. The top of the mercury in the jar was now covered with -a little diluted muriatic acid, and a small glass tube filled with a -mixture of 3 grains of charcoal, and 20 nitre. After the deflagration, -the tube itself with the residuum it contained, were thrown into the -jar. The carbonic acid was quickly detached from them by the muriatic -<span class="pagenum" id="Page_47">[Pg 47]</span> -acid, and the whole quantity of gas generated in the process, obtained; -it measured 15 cubic inches.</p> - -<p>4 cubic inches of it exposed to solution of potash, diminished to -1⁴/₁₀; 7 of the remainder, with 8 of oxygene, gave only 12.</p> - -<p>EXP. <i>f</i>. 60 grains of nitre, and 9 of charcoal were fired, the -top of the mercury in the jar being covered with water. After the -deflagration, the tube that had contained them was introduced, and -the carbonic acid contained by the carbonate of potash, disengaged by -muriatic acid. 30 measures of the gases evolved were exposed to caustic -potash; 20 exactly were absorbed, the 10 remaining, with 10 of oxygene, -diminished to 17.</p> - -<p>EXP. <i>g</i>. A mixture of nitre and charcoal were deflagrated over -a little water in the mercurial jar: after the precipitation of the -vapor, the water was absorbed by filtrating paper. This filtrating -paper, heated in a solution of potash, gave a faint smell of ammoniac.</p> - -<p>EXP. <i>h</i>. Water impregnated with the vapor produced in the -<span class="pagenum" id="Page_48">[Pg 48]</span> -deflagration, was heated with quicklime, and presented separately to -three persons accustomed to chemical odors. Two of them instantly -recognised the ammoniacal smell, the other could not ascertain it. -Paper reddened with cabbage juice was quickly turned green by the vapor.</p> - -<p>These experiments are sufficient to shew that the decomposition of -nitre by charcoal is a very complex process, and that the intense -degree of heat produced may effect changes in the substances employed, -which we are unable to estimate.</p> - -<p>The products, instead of being simply carbonic acid, and nitrogene, are -carbonic acid, nitrogene, nitrous acid, probably ammonia, and sometimes -nitrous gas. The nitrous acid is disengaged from the base by the -intense heat. Concerning the formation of the ammonia, it is useless to -reason till we have obtained unequivocal testimonies of its existence; -it may be produced either by the decomposition of the water contained -in the nitre, by the combination of its oxygene with the charcoal, and -<span class="pagenum" id="Page_49">[Pg 49]</span> -of its nascent hydrogene with the nitrogene of the nitric acid; or from -some unknown decomposition of the potash.</p> - -<p>As neither Lavoisier nor Berthollet found nitrous gas produced in -the decomposition of nitre by charcoal, when a water apparatus was -employed; and as it was not uniformly evolved in my experiments, the -most probable supposition is, that it arises from the decomposition of -a portion of the free nitrous acid intensely heated, by the mercury.</p> - -<p>In none of my experiments was the whole of the nitre and charcoal -decomposed, some of it was uniformly thrown with the gases into the -mercurial apparatus. The nitrogene evolved, as far as I could ascertain -by the common tests, was mingled with no inflammable gas.</p> - -<p>If we consider experiment <i>f</i> as accurate, with regard to the -relative quantities of carbonic acid and nitrogene produced, they are -to each other nearly as 20 to 8; that is, allowing 2 for the nitrous -gas, and consequently, reasoning in the same manner as Lavoisier, -concerning the composition of nitric acid, it should be composed -<span class="pagenum" id="Page_50">[Pg 50]</span> -of 1 nitrogene to 3,38 oxygene. But though the quantity of oxygene in -this estimation is far short of that given in his, yet still it is too -much. From whatever source the errors arise, whether from the evolution -of phlogisticated nitrous acid, or the decomposition of water, or the -production of nitrous gas, they all tend to increase the proportion of -the carbonic acid to the nitrogene.</p> - -<p>I am unacquainted with any experiment from which accurate opinions -concerning the different relative proportions of oxygene and nitrogene -in the nitric and nitrous acids could be deduced. Lavoisier’s -calculation is founded on his fundamental experiment, and on the -combination of nitrous gas and oxygene.</p> - -<p>Dr. Priestley’s experiment mentioned in section 12, on the absorption -of nitrous gas by nitrous acid, from which Kirwan<a id="FNanchor_51" href="#Footnote_51" class="fnanchor">[51]</a> -deduces the composition of the differently colored nitrous acids, was made over -<span class="pagenum" id="Page_51">[Pg 51]</span> -water, by which, as is evident from a minute examination of the -facts<a id="FNanchor_52" href="#Footnote_52" class="fnanchor">[52]</a>, -the greater portion of the nitrous gas employed was absorbed.</p> - -<p>XIV. The opinions heretofore adopted respecting the quantities of -real or true acid in solutions of nitrous acid of different specific -gravities, have been founded on experiments made on the nitro-neutral -<span class="pagenum" id="Page_52">[Pg 52]</span> -salts, the most accurate of which are those of Kirwan, Bergman, and -Wenzel. The great difference in the results of these celebrated men, -proves the difficulty of the investigation, and the existence of -sources of error.<a id="FNanchor_53" href="#Footnote_53" class="fnanchor">[53]</a> -Kirwan deduces the composition of the solutions -of nitrous acid in water, from an experiment on the formation of -nitrated soda. In this experiment, 36,05 grains of soda were saturated -by 145 grains of nitrous acid, of specific gravity 1,2754. By a -test experiment, he found the quantity of salt formed to be 85,142 -grains.<a id="FNanchor_54" href="#Footnote_54" class="fnanchor">[54]</a> -Hence he concludes that 100 parts of nitrous acid, of specific gravity -1,5543, contain 73,54 of the strongest, or most concentrated acid.</p> - -<p>Supposing his estimation perfectly true, 100 parts of the aëriform acid -of 55° would be composed of 74,54 of his real acid, and 25,46 water. In -<span class="pagenum" id="Page_53">[Pg 53]</span> -examining, however, one of his later experiments,<a id="FNanchor_55" href="#Footnote_55" class="fnanchor">[55]</a> -we shall find reasons for concluding, that the acid in nitrated soda -cannot contain much less water than the aëriform acid. A solution of -carbonated soda, containing 125 grains of real alkali, was saturated -by 306,2 grains of nitrous acid, of specific gravity 1,416. The -evaporation was carried on in a temperature not exceeding 120°, and -the residuum exposed to a heat of 400° for six hours, at the end of -which time it weighed 308 grains. Now according to my estimation, 306 -grains of nitric acid, of 1,416, should contain 215 true acid; and we -can hardly suppose, but that during the evaporation and consequent long -exposure to heat, some of the nitrated soda was lost with the water.</p> - -<p>Bergman estimates the quantity of water in this salt at 25, and the -acid at 43 per cent; but his real acid was not so concentrated as -Kirwan’s, consequently the nitric acid in nitrated soda should contain -more water than my true acid. -<span class="pagenum" id="Page_54">[Pg 54]</span></p> - -<p>Wenzel, from an experiment on the composition of nitrated soda, -concludes that it contains 37,48 of alkali, and 62,52 of nitrous acid; -and 1000 of this acid, from Kirwan’s calculation, contain 812,6 of his -real acid; consequently, 100 parts of my aëriform acid should contain -93,28 of Wenzel’s acid, and 6,72 of water.</p> - -<p>I saturated with potash 54 grains of solution of nitric acid, of -specific gravity 1,301. Evaporated at about 212°, it produced 66 grains -of nitre. This nitre exposed to a higher temperature, and kept in -fusion for some time, was reduced to 60 grains.</p> - -<p>Now from the table, 54 of 1,301, should contain 26,5 of true acid. But -according to Kirwan’s estimation, 100 parts of dry nitre contain 44<a id="FNanchor_56" href="#Footnote_56" class="fnanchor">[56]</a> -of his real acid, with 4 water; consequently 60 should contain 26,4.</p> - -<p>Again, 90 grains of acid, of specific gravity 1,504, saturated with<span class="pagenum" id="Page_55">[Pg 55]</span> -potash, and treated in the same manner, gave 173 grains of dry nitre. -Consequently, 100 parts of it should contain 47,3 grains of true acid.</p> - -<p>Now Lavoisier<a id="FNanchor_57" href="#Footnote_57" class="fnanchor">[57]</a> allows about 51 of dry acid to 100 grains of nitre, -and Wenzel 52.</p> - -<p>From Berthollet’s<a id="FNanchor_58" href="#Footnote_58" class="fnanchor">[58]</a> experiments, 100 grains of nitre, in their -decomposition by heat, give out nearly 49 grains of gas.<a id="FNanchor_59" href="#Footnote_59" class="fnanchor">[59]</a></p> - -<p>Hence it appears that the aëriform acid, that is, the true acid of my -table, contains rather less water than the acid supposed to exist in nitre. -<span class="pagenum" id="Page_56">[Pg 56]</span></p> - -<h3 id="RI_DIV_II">DIVISION II.</h3> - -<p class="neg-indent space-below1"><i>EXPERIMENTS and OBSERVATIONS on the -composition of AMMONIAC and on its combinations with WATER and NITRIC ACID.</i></p> - -<p id="RI_DII_01" class="f120">I. <i>Analysis of AMMONIAC or VOLATILE ALKALI.</i></p> - -<p class="drop-cap"><span class="smcap">The</span> formation and -decomposition of volatile alkali in many processes, was observed by -Priestley, Scheele, Bergman, Kirwan, and Higgins; but to Berthollet we -owe the discovery of its constituent parts, and their proportions to -each other. These proportions this excellent philosopher deduced from -an experiment on the decomposition of aëriform ammoniac by -the electric spark:<a id="FNanchor_60" href="#Footnote_60" class="fnanchor">[60]</a> -a process in which no apparent source of error exists. -<span class="pagenum" id="Page_57">[Pg 57]</span></p> - -<p>Since, however, his estimations have been made, the proportions of -oxygene and hydrogene in water have been more accurately determined. -This circumstance, as well as the conviction of the impossibility -of too minutely scrutinizing facts, fundamental to a great mass of -reasoning, induced me to make the following experiments.</p> - -<p>A porcelain tube was provided, open at both ends, and well glazed -inside and outside, its diameter being about,5 inches. To one end of -this, a glass tube was affixed, curved for the purpose of communicating -with the water apparatus. With the other end a glass retort was -accurately connected, containing a mixture of perfectly caustic slacked -lime, and muriate of ammoniac.</p> - -<p>The water in the apparatus for receiving the gases had been previously -boiled, to expel the air it might contain, and during the experiment -was yet warm.</p> - -<p>When the tube had been reddened in a furnace adapted to the purpose, -<span class="pagenum" id="Page_58">[Pg 58]</span> -the flame of a spirit lamp was applied to the bottom of the retort. A -great quantity of gas was collected in the water apparatus; of this the -first portions were rejected, and the last transferred to the mercurial trough.</p> - -<p>A small quantity examined, did not at all diminish with nitrous gas, -and burnt with a lambent white flame, in contact with common air.</p> - -<p>2¾ of this gas, equal to 110 grain measures, were fired with 2, equal -to 80, of oxygene, in a detonating tube, by the electric spark. They -were reduced to 2¼, or 90. On introducing to the remainder a solution -of strontian, it became slightly clouded on the top, and an absorption -of some grain measures took place.</p> - -<p>It was evident, then, that in this experiment, charcoal<a id="FNanchor_61" href="#Footnote_61" class="fnanchor">[61]</a> -had been somehow present in the tube; which being dissolved by the nascent -<span class="pagenum" id="Page_59">[Pg 59]</span> -hydrogene, had rendered it slightly carbonated, and in consequence made -the results inconclusive.</p> - -<p>A tube of thick green glass carefully made clean, was now employed, -inclosed in the porcelain tube. Every other precaution was taken to -prevent the existence of sources of error, and the experiment conducted -as before.</p> - -<p>140 grain measures of the gas produced, fired with 120 of oxygene, -left, in two experiments, nearly 110. Solution of strontian placed in -contact with the residuum, did not become clouded, and no absorption -was perceived.</p> - -<p>Now 150 measures of gas were destroyed, and if we take Lavoisier’s -and Meusnier’s estimation of the composition of water, and suppose -the weight of oxygene to be 35 grains, and that of hydrogene 2,6 the -hundred cubic inches; the oxygene employed will be to the hydrogene -as 243 to 576. Put <i>x</i> for the oxygene, and <i>y</i> for the hydrogene. -<span class="pagenum" id="Page_60">[Pg 60]</span></p> - -<div class="blockquot2"> -<p>Then</p> -<p class="f120"> <i>x</i> + <i>y</i> = 150</p> - -<p class="f120 space-below1"><i>x</i> : <i>y</i> :: 243 : 576</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdc"> </td> - <td class="tdc">243<i>y</i></td> - </tr><tr> - <td class="tdc"><i>x</i> =</td> - <td class="tdc_ws1">——</td> - </tr><tr> - <td class="tdc"> </td> - <td class="tdc">576</td> - </tr> - </tbody> -</table> - -<p class="f120 space-above1">819<i>y</i> = 86400</p> - -<p class="f120"><i>y</i> = 105 <i>x</i> = 45</p> - -<p>And</p> -<p class="f120">140 - 105 = 35</p> -</div> - -<p>Consequently, the nitrogene in ammoniac is to the hydrogene as 35: 105 -in volume: and 13,3 grains of ammoniac are composed of 10,6 nitrogene, -(supposing that 100 cubic inches weigh 30,45 grains) and 2,7 hydrogene.</p> - -<p>According to Berthollet, the weight of the nitrogene in ammoniac is -to that of the hydrogene as 121 to 29.<a id="FNanchor_62" href="#Footnote_62" class="fnanchor">[62]</a> -The difference between this estimation and mine is so small as to -be almost unworthy of notice, and arises most probably from the -slight difference between the accounts of Lavoisier and Monge, of the -composition of water, and the different weights assigned to the gases employed. -<span class="pagenum" id="Page_61">[Pg 61]</span></p> - -<p>We may then conclude, that 100 grains of ammoniac are composed of about -80 nitrogene, and 20 hydrogene.</p> - -<p>The decomposition of ammoniac by heat, as well as by the electric -spark, was first discovered by Priestley. In an experiment<a id="FNanchor_63" href="#Footnote_63" class="fnanchor">[63]</a> -when aëriform ammoniac was sent through a heated tube from a caustic -solution of ammoniac in water, this great discoverer observed that an -inflammable gas was produced, though in no great quantity, and that a -fluid blackened by matter, probably carbonaceous, likewise came over.</p> - -<p>In my experiments the whole of the ammoniac appeared to be decomposed; -the quantity of gas generated was immense, and not clouded, as is -usually the case with gases generated at high temperatures. It is -possible, that the larger quantity of water carried over in his -experiment, by its strong attraction for ammoniac in the aëriform -state, might have, in some measure, retarded the decomposition. It is -<span class="pagenum" id="Page_62">[Pg 62]</span> -however, more probable to suppose, that a fissure existed in the -earthen tube he employed, through which a certain quantity of gas -escaped, and coaly matter entered.</p> - -<p>Priestley found that the metallic oxides when strongly heated, -decomposed ammoniac, the metal being revivified and water and nitrogene -produced.<a id="FNanchor_64" href="#Footnote_64" class="fnanchor">[64]</a> -The estimations of the composition of ammoniac that may be deduced from -his experiments on the oxide of lead, differ very little from those -already detailed.</p> - -<p id="RI_DII_02" class="f120 space-above2">II. <i>Specific gravity of Ammoniac.</i></p> - -<p>From the great solubility of ammoniac in water, it is difficult to -ascertain its specific gravity in the same manner as that of a gas -combinable to no great extent with that fluid. It is impossible to -<span class="pagenum" id="Page_63">[Pg 63]</span> -prevent the existence of a small quantity of solution of ammoniac in -the mercurial airholder,<a id="FNanchor_65" href="#Footnote_65" class="fnanchor">[65]</a> -or apparatus containing the gas; and during the diminution of the pressure -of the atmosphere on this solution,<a id="FNanchor_66" href="#Footnote_66" class="fnanchor">[66]</a> -a certain quantity of gas is liberated from it, and hence a source of error.</p> - -<p>To ascertain, then, the weight of ammoniac, I employed an apparatus -similar to that used for the absorption of nitrous gas by nitric acid.</p> - -<p>50 cubic inches of gas were collected in the mercurial airholder, from -the decomposition of muriate of ammoniac by lime; thermometer being -58°, and barometer 29,6.</p> - -<p>100 grains of diluted sulphuric acid were introduced into the small -graduated cylinder, which after being carefully weighed, was made to -<span class="pagenum" id="Page_64">[Pg 64]</span> -communicate with the airholder, the curved tube containing a small -quantity of water. The gas was slowly passed into the fluid, and the -globules wholly absorbed before they reached the top; much increase of -temperature being consequent. When the absorption was compleat, the -phial was increased in weight exactly 9 grains.</p> - -<p>This experiment was repeated three times. The difference of weight, -which was probably connected with alterations of temperature and -pressure, never amounted to more than one sixth of a grain.</p> - -<p>We may then conclude, that at temperature 58°, and atmospheric pressure -29,6, 100 cubic inches of ammoniac weigh 18 grains.</p> - -<p>According to Kirwan, 100 cubic inches of alkaline air<a id="FNanchor_67" href="#Footnote_67" class="fnanchor">[67]</a> -weigh 18,16 grains; barometer 30°, thermometer 61. The difference between -these estimations, the corrections for temperature and pressure being made, -is trifling. -<span class="pagenum" id="Page_65">[Pg 65]</span></p> - -<p id="RI_DII_03" class="f120 space-above2">III. <i>Of the quantities of true -Ammoniac in Aqueous Ammoniacal Solutions, of different specific -gravities.</i></p> - -<p>To ascertain the quantities of ammoniac, such as exists in the aëriform -state, saturated with moisture, in solutions of different specific -gravities, I employed the apparatus for absorption so often mentioned. -Thermometer being 52°, the mercurial airholder was filled with -ammoniacal gas, and the graduated phial, containing 50 grains of pure -water, connected with it. During the absorption of the gas, the phial -became warm. When about 30 cubic inches had been passed through, it was -suffered to cool, and weighed: it had gained 5,25 grains, and the fluid -filled a space equal to that occupied by 57<a id="FNanchor_68" href="#Footnote_68" class="fnanchor">[68]</a> grains of water.</p> - -<p><span class="pagenum" id="Page_66">[Pg 66]</span> -Consequently, 100 grains of solution of ammoniac in water of specific -gravity,9684 contain 9,502 grains of ammoniac.</p> - -<p>The apparatus being adjusted as before, 50 grains of pure water were -now perfectly saturated with ammoniac. They gained in weight 17 -grains, and when perfectly cool, filled a space equal to 74 of water. -Consequently 100 grains of aqueous ammonial solution of specific -gravity,9054 contain 25,37 grams of ammoniac.</p> - -<p>The two solutions were mingled together; but no alteration of -temperature took place. Consequently the resulting specific gravity -might have been found by calculation.</p> - -<p>On mingling a large quantity of caustic solution of ammoniac with ¼ of -its weight of water, of exactly the same temperature, no alteration of -<span class="pagenum" id="Page_67">[Pg 67]</span> -it was perceptible by a sensible thermometer.—Hence the two -experiments<a id="FNanchor_69" href="#Footnote_69" class="fnanchor">[69]</a> -being assumed as data, the intermediate estimations in the following -table, were found by calculation. -<span class="pagenum" id="Page_68">[Pg 68]</span></p> - -<p class="f150"><b>TABLE IV.</b></p> - -<div class="blockquot2"> -<p class="center"><i>Of approximations to the quantities of AMMONIAC, -such as exists in the aëriform state, saturated with water at 52°, in -AQUEOUS AMMONIACAL SOLUTIONS of different specific gravities.</i></p> -</div> - -<table border="0" cellspacing="0" summary=" " cellpadding="0" rules="cols" > - <thead><tr> - <th class="tdc bb" colspan="4"> </th> - </tr><tr> - <th class="tdc bb">100<br />Specific Gravity. </th> - <th class="tdc bb"> </th> - <th class="tdc bb"> Ammoniac. </th> - <th class="tdc bb"> Water. </th> - </tr> - </thead> - <tbody><tr> - <td class="tdc">9054</td> - <td class="tdc"> </td> - <td class="tdc">25,37</td> - <td class="tdc">74,63</td> - </tr><tr> - <td class="tdc">9166</td> - <td class="tdc"> </td> - <td class="tdc">22,07</td> - <td class="tdc">77,93</td> - </tr><tr> - <td class="tdc">9255</td> - <td class="tdc"> </td> - <td class="tdc">19,54</td> - <td class="tdc">80,46</td> - </tr><tr> - <td class="tdc">9326</td> - <td class="tdc">c</td> - <td class="tdc">17,52</td> - <td class="tdc">82,48</td> - </tr><tr> - <td class="tdc">9385</td> - <td class="tdc">o</td> - <td class="tdc">15,88</td> - <td class="tdc">84,12</td> - </tr><tr> - <td class="tdc">9435</td> - <td class="tdc">n</td> - <td class="tdc">14,53</td> - <td class="tdc">85,47</td> - </tr><tr> - <td class="tdc">9476</td> - <td class="tdc">t</td> - <td class="tdc">13,46</td> - <td class="tdc">86,54</td> - </tr><tr> - <td class="tdc">9513</td> - <td class="tdc">a</td> - <td class="tdc">12,40</td> - <td class="tdc">87,60</td> - </tr><tr> - <td class="tdc">9545</td> - <td class="tdc">i</td> - <td class="tdc">11,56</td> - <td class="tdc">88,44</td> - </tr><tr> - <td class="tdc">9573</td> - <td class="tdc">n</td> - <td class="tdc">10,82</td> - <td class="tdc">89,18</td> - </tr><tr> - <td class="tdc">9597</td> - <td class="tdc"> </td> - <td class="tdc">10,17</td> - <td class="tdc">89,83</td> - </tr><tr> - <td class="tdc">9619</td> - <td class="tdc"> </td> - <td class="tdc"> 9,60</td> - <td class="tdc">90,40</td> - </tr><tr> - <td class="tdc">9684</td> - <td class="tdc"> </td> - <td class="tdc"> 9,50</td> - <td class="tdc">90,50</td> - </tr><tr> - <td class="tdc">9639</td> - <td class="tdc"> </td> - <td class="tdc"> 9,09</td> - <td class="tdc">90,91</td> - </tr><tr> - <td class="tdc">9713</td> - <td class="tdc"> </td> - <td class="tdc"> 7,17</td> - <td class="tdc">92,83</td> - </tr><tr> - <td class="tdc bt" colspan="4"> </td> - </tr> - </tbody> -</table> - -<p class="blockquot2">As yet no mode has been discovered for obtaining -gases in a state of absolute dryness; consequently we are ignorant of -the different quantities of water they hold in solution at different -temperatures. As far as we are acquainted with the combinations of -ammoniac, there is no state in which it exists so free from moisture, -as when aëriform, at low temperatures.</p> - -<p><span class="pagenum" id="Page_69">[Pg 69]</span> -That no considerable source of error existed in the two experiments, -is evident from the trifling difference between the estimations of the -quantities of real ammoniac, in the solution of,9684, as found in the -first experiment, and as given by calculation from the last.</p> - -<p>The quantity of ammoniac in a solution of specific gravity not in -the table, may be thus determined—find the difference between the -two specific gravities nearest to it in the table; <i>d</i>, and the -difference between their quantities of alkali, <i>b</i>; likewise the -difference between the given specific gravity and that nearest to it, -<i>c</i>.</p> - -<p class="big-indent">then</p> -<p class="f120"><i>d</i> : <i>b</i> :: <i>c</i> : <i>x</i></p> -<p class="big-indent">and</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdc"> </td> - <td class="tdc"><i>bc</i></td> - </tr><tr> - <td class="tdc"><i>x</i> =</td> - <td class="tdc_ws1">——</td> - </tr><tr> - <td class="tdc"> </td> - <td class="tdc"><i>d</i></td> - </tr> - </tbody> -</table> - -<p>Which, added to the quantity of the lower specific gravity, is the -alkali sought.</p> - -<p>The differences in specific gravity of the solutions of ammoniac at -temperatures between 4O° and 65°<a id="FNanchor_70" href="#Footnote_70" class="fnanchor">[70]</a> -are so trifling as to be hardly ascertainable, by our imperfect instruments, -<span class="pagenum" id="Page_70">[Pg 70]</span> -and consequently are unworthy of notice.</p> - -<p>It is possible at very low temperatures to obtain ammoniacal solutions -of less specific gravity than,9, but they are incapable of being kept -for any length of time under the common pressure of the atmosphere.</p> - -<p id="RI_DII_04" class="f120 space-above2">IV. <i>Combinations of Ammoniac with -Nitric Acid,<br /> Composition of Nitrate of Ammoniac, &c.</i></p> - -<p>200 grains of ammoniacal solution, of specific gravity,9056, were -saturated by 385,5 grains of nitric acid, of specific gravity 1,306. -The combination was effected in a long phial, the nitrous acid added -very slowly, and the phial closed after every addition, to prevent any -evaporation in consequence of the great increase of temperature.<a id="FNanchor_71" href="#Footnote_71" class="fnanchor">[71]</a> -The specific gravity of the solution, when reduced to the common -<span class="pagenum" id="Page_71">[Pg 71]</span> -temperature, was 1,15. Evaporated at a heat of 212°,<a id="FNanchor_72" href="#Footnote_72" class="fnanchor">[72]</a> -it gave 254 grains of salt of fibrous crystalization. This salt was -dissolved in 331 grains of water; the specific gravity of the solution -was 1,148 nearly.</p> - -<p>Hence it was evident that some of the salt had been lost during the -evaporation.</p> - -<p>To find the quantity lost, fibrous nitrate of ammoniac was dissolved -in small quantities in the solution, the specific gravity of which was -examined after every addition of 3 grains. When 16 grains had been -added to it, it became of 1,15.</p> - -<p>Consequently, the solution composed of 200 grains of ammoniacal, and -of 385,5 of nitric acid solution, contained 262 grains of salt of -fibrous crystalization, and of this salt 8 grains were lost during the -evaporation.</p> - -<p>But the alkali in 200 grains of ammoniacal solution of,9056 = 50,5 -grains. And the true nitric acid in 385,5 grains of solution of -1,306 = 190 grains. -<span class="pagenum" id="Page_72">[Pg 72]</span></p> - -<p>Then 262-240,5 = 21,5, the quantity of water.</p> - -<p>And 262 grains of fibrous crystalized nitrate of ammoniac, contain 190 -grains true acid, 50,5 ammoniac, and 21,5 water. And 100 parts contain -72,5 acid. 19,3 ammoniac, and 8,2 water.</p> - -<p>In proportion as the temperature employed for the evaporation of -nitro-ammoniacal solutions, is above or below 212°, so in proportion -does the salt produced contain more or less water than the fibrous -nitrate. But whatever may have been the temperature of evaporation, the -acid and alkali appear always to be in the same proportions to each other.</p> - -<p>Of the salts containing different quantities of water, two varieties -must be particularly noticed. The prismatic nitrate of ammoniac, -produced at the common temperatures of the atmosphere, and containing -its full quantity of water of crystalisation; and the compact nitrate -of ammoniac, either amorphous, or composed of delicately needled -<span class="pagenum" id="Page_73">[Pg 73]</span> -crystals, formed at 300°, and containing but little more water than -exists in nitric acid and ammoniac.</p> - -<p>To discover the composition of the prismatic nitrate of ammoniac, 200 -grains of fibrous salt were dissolved in the smallest possible quantity -of water, and evaporated in a temperature not exceeding 70°. The -greater part of the salt was composed of perfectly formed tetrahædral -prisms, terminated by tetrahædral pyramids. It had gained in weight -about 8,5 grains.</p> - -<p>Consequently 100 grains of prismatic nitrate of ammoniac may be -supposed to contain 69,5 acid, 18,4 ammoniac, and 12,1 water.</p> - -<p>To ascertain the composition of the compact nitrate of ammoniac, I -exposed in a deep porcelain cup, 400 grains of the fibrous salt, in a -temperature below 300°. It quickly became fluid, and slowly gave out -its water without any ebullition, or liberation of gas. When it was -become perfectly dry, it had lost 33 grains. I suspected, that in this -experiment some of the salt had been carried off with the water; to -<span class="pagenum" id="Page_74">[Pg 74]</span> -determine this, I introduced into a small glass retort, 460 grains of -fibrous salt; it was kept at a heat below 320°, in communication with a -mercurial apparatus, in a regulated air-furnace, till it was perfectly -dry: it had lost 23 grains. No gas, except the common air of the retort -came over, and the fluid collected had but a faint taste of nitrate of -ammoniac.</p> - -<p>Though in this experiment I had removed all the fluid retained in the -neck of the retort, still a few drops remained in the head, and on -the sides, which I could not obtain. It was of importance to me to be -accurately acquainted with the composition of the compact salt, and for -that reason I compared these analytical experiments with a synthetical one.</p> - -<p>I saturated 200 grains of solution of ammoniac, of,9056 with acid, -ascertained the specific gravity of the solution, evaporated it at -212°, and fused and dried it at about 300°-260°. It gave 246 grains -of salt, and a solution made of the same specific gravity as that -evaporated, indicated a loss of 9 grains. Consequently, 255 grains of -<span class="pagenum" id="Page_75">[Pg 75]</span> -this salt contain 50,5 grains alkali, 100 grains acid, and 14,5 grains -water.</p> - -<p>We may then conclude, that 100 parts of compact nitrate of ammoniac -contain 74,5 acid, 19,8 alkali, and 5,7 water.</p> - -<p id="RI_DII_05" class="f120 space-above2">V. <i>Decomposition of Carbonate of -Ammoniac by Nitric Acid.</i></p> - -<p>In my first experiments on the production of nitrate of ammoniac, I -endeavoured to ascertain its composition by decompounding carbonate -of ammoniac by nitric acid; and in making for this purpose, the -analysis of carbonate of ammoniac, I discovered that there existed -many varieties of this salt, containing very different proportions of -carbonic acid, alkali, and water; the carbonic acid and water being -superabundant in it, in proportion as the temperature of its formation -was low, and the alkali in proportion as it was high: and not only -that a different salt was formed at every different temperature, but -<span class="pagenum" id="Page_76">[Pg 76]</span> -likewise that the difference in them was so great, that the carbonate -of ammoniac formed at 300° contained more than 50 per cent alkali, -whilst that produced at 60° contained only 20.<a id="FNanchor_73" href="#Footnote_73" class="fnanchor">[73]</a></p> - -<p>I found 210 grains of carbonate of ammoniac, which from comparison with -other salts previously analised, I suspected to contain about 20 or -21 per cent alkali, saturated by 200 grains of nitric acid of 1,504. -But though the carbonate was dissolved in much water, still, from the -smell of the carbonic acid generated, I suspect that a small portion -of the nitric acid was dissolved, and carried off by it. The solution, -evaporated at about 200°, and afterwards exposed to a temperature below -300°, gave 232 grains of compact salt. But reasoning from the quantity -of acid in 200 grains of nitric acid of 1,504, it ought to have given -245. Consequently 13 were lost by evaporation; and this loss agrees -with that in the other experiments. -<span class="pagenum" id="Page_77">[Pg 77]</span></p> - -<p id="RI_DII_06" class="f120 space-above2">VI. <i>Decomposition of -Sulphate of Ammoniac by Nitre.</i></p> - -<p>As a cheap mode of obtaining nitrate of ammoniac, Dr. <span class="smcap">Beddoes</span> -proposed to decompose nitre by sulphate of ammoniac, which is a well -known article of commerce. From synthesis of sulphate of ammoniac, -compared with analysis made in August 1799,<a id="FNanchor_74" href="#Footnote_74" class="fnanchor">[74]</a> -I concluded that 100 grains of prismatic salt were composed of about -18 grains ammoniac, 44 acid, and 38 water; and supposing 100 grains -of nitre to contain 50 acid, 100 grains of sulphate of ammoniac will -require for their decomposition 134 grains of nitre, and form 90,9 -grains of compact nitrate of ammoniac. -<span class="pagenum" id="Page_78">[Pg 78]</span></p> - -<p>To ascertain if the sulphate of potash and nitrate of ammoniac could be -easily separated, I added to a heated saturated solution of sulphate of -ammoniac, pulverised nitre, till the decomposition was complete. After -this decomposition, the solution contained a slight excess of sulphuric -acid, which was combined with lime, and the whole set to evaporate at -a temperature below 250°. As soon as the sulphate of potash began to -crystalise, the solution was suffered to cool, and then poured off from -the crystalised salt, which appeared to contain no nitrate of ammoniac. -After a second evaporation and crystalisation, almost the whole of -the sulphate appeared to be deposited, and the solution of nitrate of -ammoniac was obtained nearly pure: it was evaporated at 212°, and gave -fibrous crystals.</p> - -<p id="RI_DII_07" class="f120 space-above2">VII. <i>Non-existence of Ammoniacal Nitrites.</i></p> - -<p>I attempted in different modes to combine <i>nitrous</i> acids with -ammoniac, so as to form the salts which have been supposed to exist, and -<span class="pagenum" id="Page_79">[Pg 79]</span> -called <i>nitrites</i> of ammoniac; but without success.</p> - -<p>I first decomposed a solution of carbonate of ammoniac by dilute olive -colored acid; but in this process, though no heat was generated, yet -all the nitrous gas appeared to be liberated with the carbonic acid.<a id="FNanchor_75" href="#Footnote_75" class="fnanchor">[75]</a> -I then combined a small quantity of nitrous gas, with a solution of -nitrate of ammoniac. But after evaporating this solution at 70°-80°, -I could not detect the existence of nitrous gas in the solid salt; it -was given out during the evaporation and crystalisation, and formed -into nitrous acid by the oxygene of the atmosphere. I likewise heated -nitrate of ammoniac to different degrees, and partially decomposed it, -to ascertain if in any case the acid was phlogisticated by heat: but in -<span class="pagenum" id="Page_80">[Pg 80]</span> -no experiment could I detect the existence of <i>nitrous</i> acid in -the heated salt, when it had been previously perfectly neutralised.</p> - -<p>When nitrate of ammoniac, indeed, with excess of nitric acid, is -exposed to heat, the superabundant nitric acid becomes phlogisticated, -and is then liberated from the salt, which remains neutral.<a id="FNanchor_76" href="#Footnote_76" class="fnanchor">[76]</a></p> - -<p>We may therefore conclude that nitrous gas has little or no affinity -for solid nitrate of ammoniac, and that no substance exists to which -the name <i>nitrite</i> of ammoniac can with propriety be applied.</p> - -<p id="RI_DII_08" class="f120 space-above2">VIII. <i>Of the sources of error in Analysis.</i></p> - -<p>To compare my synthesis of nitrate of ammoniac with analysis, I -endeavoured to separate the ammoniac and nitric acid from each other, -without decomposition. But in going through the analytical process, I -<span class="pagenum" id="Page_81">[Pg 81]</span> -soon discovered that it was impossible to make it accurate, without -many collateral laborious experiments on the quantities of ammoniac -soluble in water at different temperatures.</p> - -<p>At a temperature above 212°, I decomposed, by caustic slacked lime, -50 grains of compact nitrate of ammoniac in a retort communicating with -the mercurial airholder, the moisture in which had been previously -saturated with ammoniac. 22 cubic inches of gas were collected at 38°, -and from the loss of weight of the retort, it appeared that 13 grains -of solution of ammoniac in water, had been deposited by the gas.</p> - -<p>Now evidently, this solution must have contained much more alkali in -proportion to its water than that of 55°, otherwise the quantity of -ammoniac in 50 grains of salt would hardly equal 8 grains.<a id="FNanchor_77" href="#Footnote_77" class="fnanchor">[77]</a></p> - -<p><span class="pagenum" id="Page_82">[Pg 82]</span></p> - -<p id="RI_DII_09" class="f120 space-above2">IX. <i>Of the loss of Solutions of Nitrate -of Ammoniac<br /> during evaporation.</i></p> - -<p>The most concentrated solution of nitrate of ammoniac capable of -existing at 60°, is of specific gravity 1,304, and contains 33 water, -and 67 fibrous salt, per cent. When this solution is evaporated at -temperatures between 60° and 100, the salt is increased in weight by -the addition of water of crystalisation, and no portion of it is lost.</p> - -<p>During the evaporation of solutions of specific gravity 1,146 and 1,15, -at temperatures below 120°, I have never detected any loss of salt. -When the temperature of evaporation is 212°, the loss is generally from -3 to 4 grains per cent; and when from 230° to the standard of their -ebullition, from 4 to 6 grains. -<span class="pagenum" id="Page_83">[Pg 83]</span></p> - -<p>In proportion as solutions are more diluted, their loss in evaporation -at equal temperatures is greater. -<span class="pagenum" id="Page_84">[Pg 84]</span></p> - -<h3 id="RI_DIV_III">DIVISION III.</h3> - -<p class="neg-indent space-below1"><i>Decomposition of NITRATE of AMMONIAC: preparation of -RESPIRABLE NITROUS OXIDE; its ANALYSIS.</i></p> - -<p id="RI_DIII_01" class="f120">I. <i>Of the heat required for the decomposition -of<br /> NITRATE of AMMONIAC.</i></p> - -<p>The decomposition of nitrate of ammoniac has been supposed by -Cornette<a id="FNanchor_78" href="#Footnote_78" class="fnanchor">[78]</a> -to take place at temperatures below 212°, and its sublimation at 234°.</p> - -<p>Kirwan, from the non-coincidence in the accounts of its composition, -has imagined that it is partially decomposable, even by a heat of -80°.<a id="FNanchor_79" href="#Footnote_79" class="fnanchor">[79]</a></p> - -<p>To ascertain the changes effected by increase of temperature in this -salt, a glass retort was provided, tubulated for the purpose of -<span class="pagenum" id="Page_85">[Pg 85]</span> -introducing the bulb of a thermometer. After it had been made to -communicate with the mercurial airholder, and placed in a furnace, -the heat of which could be easily regulated, the thermometer was -introduced, and the retort filled with the salt, and carefully luted; -so that the appearances produced by different temperatures could be -accurately observed, and the products evolved obtained.</p> - -<p>From a number of experiments made in this manner on different salts, -the following conclusions were drawn.</p> - -<p>1st. Compact, or dry nitrate of ammoniac, undergoes little or no change -at temperatures below 260°.</p> - -<p>2dly. At temperatures between 275° and 300°, it slowly sublimes, -without decomposition, or without becoming fluid.</p> - -<p>3dly. At 320° it becomes fluid, decomposes, and still slowly sublimes; -it neither assuming, or continuing in, the fluid state, without decomposition. -<span class="pagenum" id="Page_86">[Pg 86]</span></p> - -<p>4thly. At temperatures between 340° and 480°, it decomposes rapidly.</p> - -<p>5thly. The prismatic and fibrous nitrates of ammoniac become fluid at -temperatures below 300°, and undergo ebullition at temperatures between -360° and 400°, without decomposition.</p> - -<p>6thly. They are capable of being heated to 430° without decomposition, -or sublimation, till a certain quantity of their water is evaporated.</p> - -<p>7thly. At temperatures above 450° they undergo decomposition, without -previously losing their water of crystalisation.</p> - -<p id="RI_DIII_02" class="f120 space-above1">II. <i>Decomposition of Nitrate of -Ammoniac; production of<br /> respirable Nitrous Oxide; its properties.</i></p> - -<p>200 grains of compact nitrate of ammoniac were introduced into a glass -retort, and decomposed slowly by the heat of a spirit lamp. The first -portions of the gas that came over were rejected, and the last received -<span class="pagenum" id="Page_87">[Pg 87]</span> -in jars containing mercury. No luminous appearance was perceived in -the retort during the process, and almost the whole of the salt was -resolved into fluid and gas. The fluid had a faint acid taste, and -contained some undecompounded nitrate. The gas collected exhibited the -following properties.—</p> - -<p><i>a.</i> A candle burnt in it with a brilliant flame, and crackling -noise. Before its extinction, the white inner flame became surrounded -with an exterior blue one.</p> - -<p><i>b.</i> Phosphorus introduced into it in a state of inflammation, -burnt with infinitely greater vividness than before.</p> - -<p><i>c.</i> Sulphur introduced into it when burning with a feeble blue -flame, was instantly extinguished; but when in a state of active -inflammation (that is, forming sulphuric acid) it burnt with a -beautiful and vivid rose-colored flame.</p> - -<p><i>d.</i> Inflamed charcoal, deprived of hydrogene, introduced into it, -burnt with much greater vividness than in the atmosphere. -<span class="pagenum" id="Page_88">[Pg 88]</span></p> - -<p><i>e.</i> To some fine twisted iron wire a small piece of cork was -affixed: this was inflamed, and the whole introduced into a jar of the -air. The iron burned with great vividness, and threw out bright sparks -as in oxygene.</p> - -<p><i>f.</i> 30 measures of it exposed to water previously boiled, was -rapidly absorbed; when the diminution was complete, rather more than a -measure remained.</p> - -<p><i>g.</i> Pure water saturated with it, gave it out again on -ebullition, and the gas thus produced retained all its former properties.</p> - -<p><i>h.</i> It was absorbed by red cabbage juice; but no alteration of -color took place.</p> - -<p><i>i.</i> Its taste was distinctly sweet, and its odor slight, but -agreeable.</p> - -<p><i>j.</i> It underwent no diminution when mingled with oxygene or -nitrous gas.</p> - -<p>Such were the obvious properties of the <span class="smcap">Nitrous Oxide</span>, or -the gas produced by the decomposition of nitrate of ammoniac in a -<span class="pagenum" id="Page_89">[Pg 89]</span> -temperature not exceeding 440°. Other properties of it will be -hereafter demonstrated, and its affinities fully investigated.</p> - -<p id="RI_DIII_03" class="f120 space-above1">III. <i>Of the gas remaining -after the absorption of<br /> Nitrous Oxide by Water.</i></p> - -<p>In exposing nitrous oxide at different times to rain or spring water, -and water that had been lately boiled, I found that the gas remaining -after the absorption was always least when boiled water was employed, -though from the mode of production of the nitrous oxide, I had reason -to believe that its composition was generally the same.</p> - -<p>This circumstance induced me to suppose that some of the residuum might -be gas previously contained in the water, and liberated from it in -consequence of the stronger affinity of that fluid for nitrous oxide. -But the greater part of it, I conjectured to consist of nitrogene -produced in consequence of a complete decomposition of part of the -acid, by the hydrogene. It was in endeavoring to ascertain the relative -<span class="pagenum" id="Page_90">[Pg 90]</span> -purity of nitrous oxide produced at different periods of the process of -the decomposition of nitrate of ammoniac, that I discovered the true -reason of the appearance of residual gas.</p> - -<p>I decomposed some pure nitrate of ammoniac in a small glass retort; -and after suffering the first portions to escape with the common air, -I caught the remainder in three separate vessels standing in the same -trough, filled with water that had been long boiled, and which at -the time of the experiment was so warm that I could scarcely bear my -hands in it. The different quantities collected gave the same intense -brilliancy to the flame of a taper.</p> - -<p>26 measures of each of them were separately inserted into 3 graduated -cylinders, of nearly the same capacity, over the same boiled water. -As the water cooled, the gas was absorbed by agitation. When the -diminution was complete, the residuum in each cylinder filled, as -nearly as possible, the same space; about two thirds of a measure. -<span class="pagenum" id="Page_91">[Pg 91]</span></p> - -<p>To each of the residuums I added two measures of nitrous gas; they gave -copious red vapor, and after the condensation filled a space rather -less than two measures.</p> - -<p>Hence the residual gas contained more oxygene than common air.</p> - -<p>I now introduced 26 measures of gas from one of the vessels into a -cylinder filled with unboiled spring water of the same kind.<a id="FNanchor_80" href="#Footnote_80" class="fnanchor">[80]</a> -After the absorption was complete, near two measures remained. These added to -two measures of nitrous air, diminished to 2,5 nearly.</p> - -<p>These experiments induced me to believe that the residual gas was not -produced in the decomposition of nitrate of ammoniac, but that it was -wholly liberated from the water.</p> - -<p>To ascertain this point with precision, I distilled a small quantity of -the same kind of water, which had been near an hour in ebullition, into -a graduated cylinder containing mercury. To this I introduced about one -<span class="pagenum" id="Page_92">[Pg 92]</span> -third of its bulk, i. e. 12 measures of nitrous oxide, which had been -carefully generated in the mercurial apparatus. After the absorption, -a small globule of gas only remained, which could hardly have equalled -one fourth of a measure. On admitting to this globule a minute quantity -of nitrous gas, an evident diminution took place.</p> - -<p>Though this experiment proved that in proportion as the water was free -from air, the residuum was less, and though there was no reason to -suppose that the ebullition and distillation had freed the water from -the whole of the air it had held in solution, still I considered a -decisive experiment wanting to determine whether nitrous oxide was the -only gas produced in the slow decomposition of nitrate of ammoniac, or -whether a minute quantity of oxygene was not likewise evolved.</p> - -<p>I received the middle part of the product of a decomposition of nitrate -of ammoniac, under a cylinder filled with dry mercury, and introduced -to it some strong solution of ammoniac. After the white cloud produced -<span class="pagenum" id="Page_93">[Pg 93]</span> -by the combination of the ammoniacal vapor with the nitric acid -suspended in the nitrous oxide, had been completely precipitated, I -introduced a small quantity of nitrous gas. No white vapor was produced.</p> - -<p>Now if any gas combinable with nitrous gas had existed in the cylinder, -the quantity of nitrous acid produced, however small, would have -been rendered perceptible by the ammoniacal fumes; for when a minute -globule of common air was admitted into the cylinder, white clouds were -instantly perceptible.</p> - -<p>It seems therefore reasonable to conclude,</p> - -<div class="blockquot"> -<p>1. That the residual gas of nitrous oxide, is air previously contained -in the water, (which in no case can be perfectly freed from it by -ebullition), and liberated by the stronger attraction of that fluid for -nitrous oxide.</p> - -<p>2. That nitrate of ammoniac, at temperatures below 440°, is -decompounded into pure nitrous oxide, and fluid.</p> - -<p>3. That in ascertaining the purity of nitrous oxide from its absorption -by water, corrections ought to be made for the quantity of gas dispelled -<span class="pagenum" id="Page_94">[Pg 94]</span> -from the water. This quantity in common water distilled under mercury -being about ¹/₅₀; in water simply boiled, and used when hot, about -¹/₃₆; and in common spring water, ¹/₁₂.</p> -</div> - -<p id="RI_DIII_04" class="f120 space-above1">IV. <i>Specific gravity of Nitrous Oxide.</i></p> - -<p>To understand accurately the changes taking place during the -decomposition of nitrate of ammoniac, we must be acquainted with the -specific gravity and composition of nitrous oxide.</p> - -<p>90 cubic inches of it, containing about ¹/₃₅ common air, introduced -from the mercurial airholder into an exhausted globe, increased it in -weight 44,75 grains; thermometer being 51°, and atmospheric pressure 30,7.</p> - -<p>106 cubic inches, of similar composition, weighed in like manner, -gave at the same temperature and pressure nearly 52,25 grains; and in -another experiment, when the thermometer was 41°, 53 grains. -<span class="pagenum" id="Page_95">[Pg 95]</span></p> - -<p>So that accounting for the small quantity of common air contained in -the gases weighed, we may conclude, that 100 cubic inches of pure -nitrous oxide weigh 50,1 grains at temperature 50°, and atmospheric -pressure 30,7.</p> - -<p>I was a little surprised at this great specific gravity, particularly -as I had expected, from Dr. Priestley’s observations, to find it less -heavy than atmospherical air. This philosopher supposed, from some -appearances produced by the mixture of it with aëriform ammoniac, that -it was even of less specific gravity than that gas.<a id="FNanchor_81" href="#Footnote_81" class="fnanchor">[81]</a></p> - -<p id="RI_DIII_05" class="f120 space-above1">V. <i>Analysis of Nitrous Oxide.</i></p> - -<p>The nitrous oxide may be analised, either by charcoal or hydrogene; -during the combustion of other bodies in it, small portions of nitrous -acid are generally formed, as will be fully explained hereafter. -<span class="pagenum" id="Page_96">[Pg 96]</span></p> - -<p>The gas that I employed was generated from compact nitrate of ammoniac, -and was in its highest state of purity, as it left a residuum of ¹/₃₈ -only, when absorbed by boiled water.</p> - -<p>10 cubic inches of it were inserted into a jar graduated to,1 cubic -inches, containing dry mercury. Through this mercury a piece of -charcoal which had been deprived of its hydrogene by long exposure -to heat, weighing about a grain, was introduced, while yet warm. No -perceptible absorption of the gas took place.<a id="FNanchor_82" href="#Footnote_82" class="fnanchor">[82]</a></p> - -<p>Thermometer being 46°, the focus of a lens was thrown on the charcoal, -which instantly took fire, and burnt vividly for about a minute, the -gas being increased in volume. After the vivid combustion had ceased, -the focus was again thrown on the charcoal; it continued to burn for -near ten minutes, when the process stopped.</p> - -<p>The gas, when the original pressure and temperature were restored, -filled a space equal to 12,5 cubic inches. -<span class="pagenum" id="Page_97">[Pg 97]</span></p> - -<p>On introducing to it a small quantity of strong solution of -ammoniac<a id="FNanchor_83" href="#Footnote_83" class="fnanchor">[83]</a>, -white vapor was instantly perceived, and after a short time the -reduction was to about 10,1 cubic inches; so that apparently, 2,4 cubic -inches of carbonic acid had been formed. The 10,1 cubic inches of gas -remaining were exposed to water which had been long in ebullition, -and which was introduced whilst boiling, under mercury. After the -absorption of the nitrous oxide by the water, the gas remaining was -equal to 5,3.</p> - -<p>But on combining a cubic inch of pure nitrous oxide with some of the -same water, which had been received under mercury in a separate vessel, -nearly ¹/₂₂ remained. Consequently we may conclude, that 5,1 of a gas -unabsorbable by water, was produced in the combustion.</p> - -<p>This gas extinguished flame, gave no diminution with oxygene, and the -<span class="pagenum" id="Page_98">[Pg 98]</span> -slightest possible with nitrous gas. When an electric spark was -passed through it, mingled with oxygene; no inflammation, or -<i>perceptible</i> diminution took place.<a id="FNanchor_84" href="#Footnote_84" class="fnanchor">[84]</a> -We may consequently conclude that it was nitrogene, mingled with a -minute portion of common air, expelled from the water.</p> - -<p>The charcoal was diminished in bulk to one half nearly, but the loss of -weight could not be ascertained, as its pores were filled with mercury.</p> - -<p>Now 5 cubic inches of nitrous oxide were absorbed by the water, -consequently 5 were decompounded by the charcoal; and these produced -5,1 cubic inches of nitrogene; and by giving their oxygene to the -charcoal, apparently 2,4 of carbonic acid.</p> - -<p>But 5 cubic inches of nitrous oxide weigh 2,5 grains, and 5,1 cubic -inches of nitrogene 1,55; then 2,5-1,55 =,95. -<span class="pagenum" id="Page_99">[Pg 99]</span></p> - -<p>So that reasoning from the relative specific gravities of nitrogene and -nitrous oxide, 2,5 grains of the last are composed of 1,55 nitrogene, -and,95 oxygene.</p> - -<p>But from many experiments made on the specific gravity of carbonic -acid, in August, 1799, I concluded that 100 cubic inches of it weighed -47,5 grains, thermometer being 60,1°, and barometer 29,5. Consequently, -making the necessary corrections, 2,4 cubic inches of it weigh -1,14 grains; and on Lavoisier’s and Guyton’s<a id="FNanchor_85" href="#Footnote_85" class="fnanchor">[85]</a> -estimation of its composition, these 1,13 grains contain 8,2 of oxygene.</p> - -<p>So that, drawing conclusions from the quantity of carbonic acid formed -in this experiment, 2,5 grains of nitrous oxide will be composed of,82 -oxygene, and 1,68 nitrogene.</p> - -<p>The difference between these estimations is considerable, and yet not -more than might have been expected, if we consider the probable sources -of error in the experiment. -<span class="pagenum" id="Page_100">[Pg 100]</span></p> - -<p>1. It is likely that variable minute quantities of hydrogene remain -combined with charcoal, even after it has been long exposed to a red -heat.</p> - -<p>2. It is probable that the nitrogene and carbonic acid produced were -capable of dissolving more water than that held in solution by the -nitrous oxide; and if so, they were more condensed than if saturated -with moisture, and hence the quantity of carbonic acid under-rated.</p> - -<p>We may consequently suppose the estimation founded on the quantity of -nitrogene evolved, most correct; and making a small allowance for the -difference, conclude, that 100 grains of nitrous oxide are composed of -about 37 oxygene, and 63 nitrogene; existing in a much more condensed -state than when in their simple forms.</p> - -<p>The tolerable accuracy of this statement will be hereafter demonstrated -by a number of experiments on the combustion of different bodies in -nitrous oxide, detailed in <a href="#RES_II">Research II</a>. -<span class="pagenum" id="Page_101">[Pg 101]</span></p> - -<p id="RI_DIII_06" class="f120 space-above1">VI. <i>Minute examination -of the decomposition of Nitrate of Ammoniac.</i></p> - -<p>Into a retort weighing 413,75 grains, and of the capacity of 7,5 -cubic inches, 100 grains of pulverised compact nitrate of ammoniac -were introduced. To the neck of this retort was adapted a recipient, -weighing 711 grains, tubulated for the purpose of communicating with -the mercurial airholder, and of the capacity of 8,3 cubic inches.</p> - -<p>Temperature being 50° and atmospheric pressure 30,6, the recipient -was inserted into a vessel of cold water, and made to communicate -with the airholder. The heat of a spirit lamp was then slowly applied -to the retort: the salt quickly began to decompose, and to liquify. -The temperature was so regulated, as to keep up an equable and slow -decomposition.</p> - -<p>During this decomposition, no luminous appearance was perceived in the -<span class="pagenum" id="Page_102">[Pg 102]</span> -retort; the gas that came into the airholder was very little clouded, -and much water condensed in the receiver.</p> - -<p>After the process was finished, the communication between the mercurial -airholder and the recipient was preserved till the common temperature -was restored to the retort.</p> - -<p>The volume of the gas in the cylinder was 85,5 cubic inches. The -absolute quantity of nitrous oxide in those 85,5 cubic inches, it was -difficult to ascertain with great nicety, on account of the common air -previously contained in the vessels.</p> - -<p>45 measures of it, exposed to well boiled water, diminished by -agitation to 8 measures. So that reasoning from the quantity of air, -which should have been expelled from the water by the nitrous oxide, we -may conclude that the 85,5 cubic inches were nearly pure.</p> - -<p>The retort now weighed 419,25 grains, consequently 5,5 grains of salt -remained in it. This salt was chiefly collected about the lower part of -<span class="pagenum" id="Page_103">[Pg 103]</span> -the neck, and contained rather more water than the compact nitrate, as -in some places it was crystalised.</p> - -<p>The recipient with the fluid it contained, weighed 759 grains. It had -consequently gained in weight 48 grains.</p> - -<p>Now the 85,5 cubic inches of nitrous oxide produced, weigh about 42,5 -grains; and this added to 48 and 5,5, = 96 grains; so that about 4 -grains of salt and fluid were lost, probably by being carried over and -deposited by the gas.<a id="FNanchor_86" href="#Footnote_86" class="fnanchor">[86]</a></p> - -<p>As much of the fluid as could be taken out of the recipient, weighed -46 grains, and held in solution much nitrate of ammoniac with -superabundance of acid. This acid required for its saturation, 3⅛ of -carbonate of ammoniac (containing, as well as I could guess), about 20 -per cent alkali.</p> - -<p>The whole solution evaporated, gave 18 grains of compact nitrate of -<span class="pagenum" id="Page_104">[Pg 104]</span> -ammoniac. But reasoning from the quantity of carbonate of ammoniac -employed, the free nitric acid was equal to 2,75 grains, and this must -have formed 3,56 grains of salt. Consequently the salt pre-existing in -the solution was about 14,44 grains.</p> - -<p>But besides the fluid taken out of the recipient, 2 grains remained in -it: let us suppose this, and the 4 grains lost, to contain 2 of salt, -and,6 of free acid.</p> - -<p>Then the undecompounded</p> - -<table border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdr">salt is 5,5 + 14,4 + 2 =</td> - <td class="tdl_ws1">21,9</td> - </tr><tr> - <td class="tdr">The free acid 2,75 + ,6 =</td> - <td class="tdl_ws1"> 3,35</td> - </tr><tr> - <td class="tdl">Gas</td> - <td class="tdl_ws1">42,5</td> - </tr><tr> - <td class="tdl">Water</td> - <td class="tdl_ws1 bb2">32,25</td> - </tr><tr> - <td class="tdr"> </td> - <td class="tdl">100</td> - </tr> - </tbody> -</table> - -<p>Now about 78,1 grains of salt were decompounded, and formed into 42,5 -grains of gas, 3,35 grains acid, and 32,25 grains water.</p> - -<p>But there is every reason to suppose, that in this process, when the -hydrogene of the ammoniac combines with a portion of the oxygene of the -<span class="pagenum" id="Page_105">[Pg 105]</span> -nitric acid to form water, and the nitrogene enters into union with the -nitrogene and remaining oxygene of the nitric acid, to form nitrous -oxide; that water pre-existing in nitric acid and ammoniac, such -as they existed in the aëriform state, is deposited with the water -produced by the new arrangement, and not wholly combined with the -nitrous oxide formed. Hence it is impossible to determine with great -exactness, the quantity of water which was absolutely formed in this -experiment.</p> - -<p>78,1 grains of salt are composed of 15,4 alkali, 58 acid, and 4,7 water.</p> - -<p>And reasoning from the different affinities of water for nitric acid, -ammoniac, and nitrous oxide, it is probable that ammoniac, in its -decomposition, divides its water in such a ratio, between the nitrogene -furnished to the nitrous oxide, and the hydrogene entering into union -with the oxygene of the nitric acid, as to enable us to assume, that -the hydrogene requires for its saturation nearly the same quantity of -oxygene as when in the aëriform state; or that it certainly cannot require less. -<span class="pagenum" id="Page_106">[Pg 106]</span></p> - -<p>But 15,4 alkali contain 3,08 hydrogene, and 12,32 nitrogene;<a id="FNanchor_87" href="#Footnote_87" class="fnanchor">[87]</a> -and 3,08 hydrogene require 17,4 of oxygene to form 20,48 of water.</p> - -<p>Now 32,5 grains of water existed before the experiment; 4,7 grains of -water were contained by the salt decomposed, and 32,5-4,7 = 27,8: and -27,8-20,48, the quantity generated, = 7,52, the quantity existing in -the nitric acid.</p> - -<p>But the nitric acid decomposed is 58ᵍ-3,35 = to 54,7; and 54,7-7,5 -= 47,2, which entered into new combinations. These 47,2 consist of 33,2 -oxygene, and 14, nitrogene. And 33,2-17,4, the quantity employed -to form the water, = 15,8, which combined with 14,0, nitrogene of -the nitric acid, and 12,32 of that of the ammoniac, to form 42,12 of -nitrous oxide. And on this estimation, 100 parts of nitrous oxide would -contain 37,6 oxygene, and 62,4 nitrogene; a computation much nearer the -<span class="pagenum" id="Page_107">[Pg 107]</span> -results of the analysis than could have been expected, particularly as -so many unavoidable sources of error existed in the process.</p> - -<p>The experiment that I have detailed is the most accurate of four, made -on the same quantity of salt. The others were carried on at rather -higher temperatures, in consequence of which, more water and salt were -sublimed with the gas.</p> - -<p>To Berthollet, we owe the discovery of the products evolved during the -slow decomposition of nitrate of ammoniac; but as this philosopher -in his examination of this process, chiefly designed to prove the -existence of hydrogene in ammoniac, he did not ascertain the quantity -of gas produced, or minutely examine its properties; from two of -them, its absorption by water and its capability of supporting the -vivid combustion of a taper, he inferred its identity with the -dephlogisticated nitrous gas of Priestley, and concluded that it was -nitrous gas with excess of pure air.<a id="FNanchor_88" href="#Footnote_88" class="fnanchor">[88]</a></p> - -<p><span class="pagenum" id="Page_108">[Pg 108]</span></p> - -<p id="RI_DIII_07" class="f120 space-above1">VII. <i>Of the heat -produced during the decomposition<br /> of nitrate of ammoniac.</i></p> - -<p>To ascertain whether the temperature of nitrate of ammoniac was -increased or diminished after it had been raised to the point essential -to its decomposition, during the evolution of nitrous oxide and water; -that is, in common language, whether heat was generated or absorbed -in the process; I introduced a thermometer into about 1500 grains of -fibrous nitrate of ammoniac, rendered liquid in a deep porcelain cup. -During the whole of the evaporation, the temperature was about 380°, -the fire being carefully regulated.</p> - -<p>As soon as the decomposition took place, the thermometer began to rise; -in less than a quarter of a minute it was 410°, in two minutes it was 460°.</p> - -<p>The cup was removed from the fire; the decomposition still went on -rapidly, and for about a minute the thermometer was stationary. It then -<span class="pagenum" id="Page_109">[Pg 109]</span> -gradually and slowly fell; in three minutes it was 440°, in five -minutes 420°, in seven minutes 405° in nine minutes 360° and in -thirteen minutes 307°, when the decomposition had nearly ceased, and -the salt began to solidify.</p> - -<p>From this experiment, it is evident that an increase of temperature -is produced by the decomposition of nitrate of ammoniac: though the -capacity of water and nitrous oxide for heat, supposing the truth of -the common doctrine, and reasoning from analogy, must be considerably -greater than that of the salt.</p> - -<p id="RI_DIII_08" class="f120 space-above1">VIII. <i>Of the decomposition -of Nitrate of Ammoniac<br /> at high temperatures, and production of<br /> -Nitrous gas, Nitrogene, Nitrous Acid, and Water.</i></p> - -<p>At an early period of my investigation relating to the nitrous oxide, -I discovered that when a heat above 600° was applied to nitrate of -ammoniac, so that a vivid luminous appearance was produced in the -retort, certain portions of nitrous gas, and nitrogene, were evolved -<span class="pagenum" id="Page_110">[Pg 110]</span> -with the nitrous oxide. But I was for some time ignorant of the -precise nature of this decomposition, and doubtful with regard to -the possibility of effecting it in such a manner as to prevent the -production of nitrous oxide altogether.</p> - -<p>I first attempted to decompose nitrate of ammoniac at high -temperatures, by introducing it into a well coated green glass retort, -having a wide neck, communicating with the pneumatic apparatus, and -strongly heated in an air-furnace. But though in this process a -detonation always took place, and much light was produced, yet still -the greater portion of the gas generated was nitrous oxide; the nitrous -gas and nitrogene never amounting to more than one third of the whole.</p> - -<p>After breaking many retorts by explosions, without gaining any accurate -results, I employed a porcelain tube, curved so as to be capable of -introduction into the pneumatic apparatus, and closed at one end.</p> - -<p>The closed end was heated red, nitrate of ammoniac introduced into it, -<span class="pagenum" id="Page_111">[Pg 111]</span> -and all the latter portions of gas produced in the explosion, received -in the pneumatic apparatus, filled with warm water.</p> - -<p>Three explosions were required to fill a jar of the capacity of 20 -cubic inches. The gas produced in the first, when it came over, was -transparent and dark orange, similar in its appearance to the nitrous -acid gas produced in the first experiment; but it speedily became white -and clouded, whilst a slight diminution of volume took place.</p> - -<p>When the second portion was generated and mingled with the clouded -gas, it again became transparent and yellow for a short time, and then -assumed the same appearance as before.</p> - -<p>The water in the trough, after this experiment, had an acid taste, and -quickly reddened cabbage juice rendered green by an alkali.</p> - -<p>6 cubic inches of the gas produced were exposed to boiled water, but -little or no absorption took place. Hence, evidently, it contained no -nitrous oxide. -<span class="pagenum" id="Page_112">[Pg 112]</span></p> - -<p>They were then exposed to solution of sulphate of iron: the solution -quickly became dark colored, and an absorption of 1,6 took place on -agitation.<a id="FNanchor_89" href="#Footnote_89" class="fnanchor">[89]</a></p> - -<p>The gas remaining instantly extinguished the taper, and was -consequently nitrogene.</p> - -<p>This experiment was repeated, with nearly the same results.</p> - -<p>We may then conclude, that at high temperatures, nitrate of ammoniac is -wholly resolved into water, nitrous acid, nitrous gas, and nitrogene; -whilst a vivid luminous appearance is produced.</p> - -<p>The transparency and orange color produced in the gas that had been -clouded, by new portions of it, doubtless arose from the solution of -the nitric acid and water forming the cloud, in the heated nitrous -vapor produced, so as to constitute an aëriform triple compound; whilst -<span class="pagenum" id="Page_113">[Pg 113]</span> -the cloudiness and absorption subsequent were produced by the -diminished temperature, which destroyed the ternary combination, and -separated the nitrous acid and water from the nitrous gas.</p> - -<p>From the rapidity with which the deflagration of nitrate of ammoniac -proceeds, and from the immense quantity of light produced, it is -reasonable to suppose that a very great increase of temperature takes -place. The tube in which the decomposition has been effected, is always -ignited after the process.</p> - -<p id="RI_DIII_09" class="f120 space-above1">IX. <i>Speculations on the -decompositions of<br /> Nitrate of Ammoniac.</i></p> - -<p>All the phænomena of chemistry concur in proving, that the affinity of -one body, A, for another, B, is not destroyed by its combination with a -third, C, but only modified; either by condensation, or expansion, or -by the attraction of C for B.</p> - -<p>On this principle, the attraction of compound bodies for each other -<span class="pagenum" id="Page_114">[Pg 114]</span> -must be resolved into the reciprocal attractions of their constituents, -and consequently the changes produced in them by variations of -temperature explained, from the alterations produced in the attractions -of those constituents.</p> - -<p>Thus in nitrate of ammoniac, four affinities may be supposed to exist:</p> - -<div class="blockquot"> -<p>1. That of hydrogene for nitrogene, producing ammoniac.</p> - -<p>2. That of oxygene for nitrous gas, producing nitric acid.</p> - -<p>3. That of the hydrogene of ammoniac for the oxygene -of nitric acid.</p> - -<p>4. That of the nitrogene of ammoniac for the nitrous gas -of nitric acid.</p> -</div> - -<p>At temperatures below 300°, the salt, from the equilibrium between -these affinities, preserves its existence.</p> - -<p>Now when its temperature is raised to 400°, the attractions of -<span class="pagenum" id="Page_115">[Pg 115]</span> -hydrogene for nitrogene,<a id="FNanchor_90" href="#Footnote_90" class="fnanchor">[90]</a> -and of nitrous gas for oxygene,<a id="FNanchor_91" href="#Footnote_91" class="fnanchor">[91]</a> -are diminished; whilst the attraction of hydrogene for -oxygene<a id="FNanchor_92" href="#Footnote_92" class="fnanchor">[92]</a> -is increased; and perhaps that of nitrogene for nitrous gas.</p> - -<p>Hence the former equilibrium of affinity is destroyed, and a new one -produced.</p> - -<p>The hydrogene of the ammoniac combines with the oxygene of the nitric -acid to generate water; and the nitrogene of the ammoniac enters into -combination with the nitrous gas to form nitrous oxide: and the water -and nitrous oxide produced, most probably exist in binary combination -in the aëriform state, at the temperature of the decomposition.</p> - -<p>But when a heat above 800° is applied to nitrate of ammoniac, the -attractions of nitrogene and hydrogene for each other, and of oxygene -<span class="pagenum" id="Page_116">[Pg 116]</span> -for nitrous gas,<a id="FNanchor_93" href="#Footnote_93" class="fnanchor">[93]</a> -are still more diminished; whilst that of nitrogene for nitrous gas -is destroyed, and that of hydrogene for oxygene increased to a great -extent: likewise a new attraction takes place; that of nitrous gas for -nitric acid, to form nitrous vapor.<a id="FNanchor_94" href="#Footnote_94" class="fnanchor">[94]</a> -Hence a new arrangement of principles is rapidly produced; the nitrogene of -ammoniac having no affinity for any of the single principles at this -temperature, enters into no binary compound: the oxygene of the nitric -acid forms water with the hydrogene, and the nitrous gas combines -with the nitric acid to form nitrous vapor. All these substances most -probably exist in combination at the temperature of their production; -and at a lower temperature, assume the forms of nitrous acid, nitrous -gas, nitrogene, and water. -<span class="pagenum" id="Page_117">[Pg 117]</span></p> - -<p>I have avoided entering into any discussions concerning the light -and heat produced in this process; because these phænomena cannot be -reasoned upon as isolated facts, and their relation to general theory -will be treated of hereafter.</p> - -<p id="RI_DIII_10" class="f120 space-above1">X. <i>On the preparation -of Nitrous Oxide<br /> for experiments on Respiration.</i></p> - -<p>When compact nitrate of ammoniac is slowly decomposed, the nitrous -oxide produced is almost immediately fit for respiration; but as one -<span class="pagenum" id="Page_118">[Pg 118]</span> -part of the salt begins to decompose before the other is rendered -fluid, a considerable loss is produced by sublimation.</p> - -<p>For the production of large quantities of nitrous oxide, fibrous -nitrate of ammoniac should be employed. This salt undergoes no -decomposition till the greater part of its water is evaporated, and in -consequence at the commencement of that process, is uniformly heated.</p> - -<p>The gas produced from fibrous nitrate, must be suffered to rest at -least for an hour after its generation. At the end of this time it is -generally fit for respiration. If examined before, it will be found -to contain more or less of a white vapor, which has a disagreeable -acidulous taste, and strongly irritates the fauces and lungs. This -vapor, most probably, consists of acid nitrate of ammoniac and water, -which were dissolved by the gas at the temperature of its production, -and afterwards slowly precipitated.</p> - -<p>It is found in less quantity when compact nitrate is employed, -because more salt is sublimed in this process, which being rapidly -precipitated, carries with it the acid and water. -<span class="pagenum" id="Page_119">[Pg 119]</span></p> - -<p>Whatever salt is employed, the last portions of gas produced, generally -contain less vapor, and may in consequence be respired sooner than the first.</p> - -<p>The nitrate of ammoniac should never be decomposed in a metallic -vessel,<a id="FNanchor_95" href="#Footnote_95" class="fnanchor">[95]</a> -nor the gas produced suffered to come in contact with any metallic -surface; for in this case the free nitric acid will be decomposed, and -in consequence, a certain quantity of nitrous gas produced.</p> - -<p>The apparatus that has been generally employed in the medical pneumatic -institution, for the production of nitrous oxide, consists</p> - -<div class="blockquot"> -<p>1. Of a glass retort, of the capacity of two or three quarts, -orificed at the top, and furnished with a ground stopper.</p> - -<p>2. Of a glass tube, conical for the purpose of receiving the -neck of the retort; about ,4 inches wide in the narrowest -part, 4 feet long, curved at the extremity, so as to be -capable of introduction into an airholder, and inclosed by -<span class="pagenum" id="Page_120">[Pg 120]</span> -tin plate to preserve it from injury.</p> - -<p>3. Of airholders of Mr. Watt’s invention, filled with water -saturated with nitrous oxide.</p> - -<p>4. Of a common air-furnace, provided with dampers for the -regulation of the heat.</p> -</div> - -<p>The retort, after the insertion of the salt, is connected with the -tube, carefully luted, and exposed to the heat of the furnace, on a -convenient stand. The temperature is never suffered to be above 500°. -After the decomposition has proceeded for about a minute, so that the -gas evolved from the tube enlarges the flame of a taper, the curved end -is inserted into the airholder, and the nitrous oxide preserved.</p> - -<p>The water thrown out of the airholders in consequence of the -introduction of the gas, is preserved in a vessel adapted for the -purpose, and employed to fill them again; for if common water was to -be employed in every experiment, a great loss of gas would be produced -from absorption. -<span class="pagenum" id="Page_121">[Pg 121]</span></p> - -<p>A pound of fibrous nitrate of ammoniac, decomposed at a heat not above -500°, produces nearly 5 cubic feet of gas; whilst from a pound of -compact nitrate of ammoniac, rarely more than 4,25 cubic feet can be -collected.</p> - -<p>For the production of nitrous oxide in quantities not exceeding 20 -quarts, a mode still more simple than that I have just described may be -employed. The salt may be decomposed by the heat of an argands lamp, or -a common fire, in a tubulated glass retort, of 20 or 30 cubic inches in -capacity, furnished with a long neck, curved at the extremity; and the -gas received in small airholders.</p> - -<p>Thus, if the pleasurable effects, or medical properties of the nitrous -oxide, should ever make it an article of general request, it may be -procured with much less time, labor, and expence,<a id="FNanchor_96" href="#Footnote_96" class="fnanchor">[96]</a> -than most of the luxuries, or even necessaries, of life. -<span class="pagenum" id="Page_122">[Pg 122]</span></p> - -<h3 id="RI_DIV_IV">DIVISION IV.</h3> - -<p class="neg-indent space-below1"><i>EXPERIMENTS and OBSERVATIONS on -the COMPOSITION of NITROUS GAS, and on its ABSORPTION by different bodies.</i></p> - -<p id="RI_DIV_01" class="f120">I. <i>Preliminaries.</i></p> - -<p class="drop-cap"><span class="smcap">In</span> my account of the -composition of nitric acid, in <a href="#RI_DIV_I">Division I</a>. -I gave an estimation of the quantities of oxygene and nitrogene -combined in nitrous gas: I shall now detail the experiments on which -that estimation is founded.</p> - -<p>At an early period of my researches relating to nitrous oxide, from -the observation of the phænomena taking place during the production of -this substance, I had concluded, that the common opinion with regard -to the composition of nitrous gas, was very distant from the truth. I -had indeed analysed nitrous gas, by converting it into nitrous oxide, -<span class="pagenum" id="Page_123">[Pg 123]</span> -before I attempted to ascertain its composition by immediately -separating the constituent principles from each other: and my first -hopes of the possibility of effecting this, were derived from Dr. -Priestley’s experiments on the combustion of pyrophorus in nitrous gas, -and on the changes effected in it, by heated iron and charcoal.</p> - -<p>This great philosopher found, that pyrophorus placed in contact with -nitrous gas, burnt with great vividness, whilst the gas was diminished -in volume to about one half, which generally consisted of nitrogene -and nitrous oxide. He likewise found, iron heated by a lens in nitrous -gas, increased in weight, whilst the gas was diminished about ½, and -converted into nitrogene.<a id="FNanchor_97" href="#Footnote_97" class="fnanchor">[97]</a></p> - -<p>He heated common charcoal, and charcoal of copper,<a id="FNanchor_98" href="#Footnote_98" class="fnanchor">[98]</a> -in nitrous gas by a lens. When common charcoal was employed, the gas was neither -increased or diminished in bulk, but wholly converted into nitrogene; -when charcoal of copper was used, the volume was a little increased, -and the gas remaining consisted of ⁵/₇ nitrogene, and ²/₇ carbonic acid. -<span class="pagenum" id="Page_124">[Pg 124]</span></p> - -<p>In his experiments on the iron and pyrophyrus, the nitrous gas -was evidently decomposed. From the great quantity of nitrogene -produced in those on the charcoal, it seems likely that both the -common charcoal,<a id="FNanchor_99" href="#Footnote_99" class="fnanchor">[99]</a> -and the charcoal of copper employed contained atmospherical air, which -being dispelled by the heat of the lens, was decomposed by the nitrous -gas: indeed, till I made the following experiment, I suspected that the -carbonic acid produced, when the charcoal of copper was employed, arose -from a decomposition of the nitrous acid, formed in this way. -<span class="pagenum" id="Page_125">[Pg 125]</span></p> - -<p>I introduced a piece of well-burnt charcoal, which could hardly have -weighed the eighth of a grain, whilst red hot, under a cylinder filled -with mercury, and admitted to it half a cubic inch of nitrous gas. A -slight absorption took place.</p> - -<p>The sun being very bright, I kept the charcoal in the focus of a -small lens for near a quarter of an hour. At the end of this time -the gas occupied a space nearly as before the experiment, and a very -minute portion of the charcoal had been consumed. On introducing -into the cylinder a small quantity of solution of strontian, a white -precipitation was perceived, and the gas slowly diminished to about -<span class="pagenum" id="Page_126">[Pg 126]</span> -three tenths of a cubic inch. To these three tenths a little common air -was admitted, when very slight red fumes were perceived.</p> - -<p>This experiment convinced me, that the attraction of charcoal for the -oxygene of nitrous gas, at high temperatures, was sufficiently strong -to effect a slow decomposition of it.</p> - -<p>To be more accurately acquainted with this decomposition, and to learn -the quantities of carbonic acid and nitrogene produced from a known -quantity of nitrous gas, I proceeded in the following manner.</p> - -<p id="RI_DIV_02" class="f120 space-above1">II. <i>Analysis of Nitrous Gas by Charcoal.</i></p> - -<p>A quantity of nitrous gas was procured in a water apparatus, from -the decomposition of nitrous acid by mercury. A portion of it was -transferred to the mercurial trough. After the mercury and the jar -had been dried by bibulous paper, 40 measures of this portion were -agitated in a solution of sulphate of iron. The gas remaining after the -<span class="pagenum" id="Page_127">[Pg 127]</span> -absorption was complete, filled about a measure and half; so that the -nitrous gas contained nearly ¹/₂₆ nitrogene.</p> - -<p>Thermometer being 53°, a small piece of well-burnt charcoal, the -weight of which could hardly have equalled a quarter of a grain, -was introduced ignited, into a small cylinder filled with mercury, -graduated to,10 grain measures; to this, 16 measures, equal to 160 -grain m. of nitrous gas, were admitted. An absorption of about one -measure and half took place. When the focus of a lens was thrown on the -charcoal, a slight increase of the gas was produced, from the emission -of that which had been absorbed.</p> - -<p>After the process had been carried on for about a half an hour, the -charcoal evidently began to fume, and to consume very slowly, though no -alteration in the volume of the gas was observed.</p> - -<p>The sun not constantly shining, the progress of the experiment was -now and then stopped: but taking the whole time, the focus could not -have been applied to it for less than four hours. When the process was -<span class="pagenum" id="Page_128">[Pg 128]</span> -finished, the gas was increased in bulk nearly three quarters of a measure.</p> - -<p>A drop of water was introduced into the cylinder, by means of a small -glass tube, on the supposition that the carbonic acid, and nitrogene, -might be capable of holding in solution, more water than that contained -in the nitrous gas decomposed; but no alteration of volume took place.</p> - -<p>When 20 grain measures of solution of pale green<a id="FNanchor_100" href="#Footnote_100" class="fnanchor">[100]</a> -sulphate of iron were introduced into the cylinder, they became rather yellower -than before, but not dark at the edges, as is always the case when nitrous -gas is present. On agitation, a diminution of nearly half a measure was -produced, doubtless from the absorption of some of the carbonic acid by -the solution.</p> - -<p>A small quantity of caustic potash, much more than was sufficient to -decompose the sulphate of iron, was now introduced. A rapid diminution -<span class="pagenum" id="Page_129">[Pg 129]</span> -took place, and the gas remaining filled about 8 measures. This gas was -agitated for some time over water, but no absorption took place. Two -measures of it were then transferred into a detonating cylinder with -two measures of oxygene. The electric spark was puffed through them, -but no diminution was produced. Hence it was nitrogene, mingled with no -ascertainable quantity of hydrogene: consequently little or no water -could have been decomposed in the process.</p> - -<p>Now supposing, for the greater ease of calculation, each of the -measures employed, cubic inches.</p> - -<p>16 of nitrous gas—¹/₂₆ = 15,4 were decomposed, and these weigh, making -the necessary corrections, 5,2; but 7,4 nitrogene were produced, and -these weigh about 2,2. So that reasoning from the relative specific -gravities of nitrous gas and nitrogene, 5,2 grains of nitrous gas will -be composed of 3 oxygene, and 2,2 nitrogene.</p> - -<p>But 8,7 of carbonic acid were produced, which weigh 4,1 grains, and -<span class="pagenum" id="Page_130">[Pg 130]</span> -consist of 2,9 oxygene, and 1,2 charcoal.<a id="FNanchor_101" href="#Footnote_101" class="fnanchor">[101]</a> -Consequently, drawing conclusions from the quantity of carbonic acid formed, -5,2 grains of nitrous gas will consist of 2,9 oxygene, and 2,3 nitrogene.</p> - -<p>The difference in these estimations is much less than could have been -expected; and taking the mean proportions, it would be inferred from them, -that 100 grains of nitrous gas, contain 56,5 oxygene, and 43,5 nitrogene.</p> - -<p>I repeated this experiment with results not very different, except that -the increase of volume was rather greater, and that more unabsorbable -gas remained; which probably depended on the decomposition of a minute -quantity of water, that had adhered to the charcoal in passing through -the mercury.</p> - -<p>As nitrous gas is decomposable into nitrous acid, and nitrogene, by the -electric spark; it occurred to me, that a certain quantity of nitrous -acid might have been possibly produced, in the experiments on the -<span class="pagenum" id="Page_131">[Pg 131]</span> -decomposition of nitrous gas, by the intensely ignited charcoal. To -ascertain this circumstance, I introduced into 12 measures of nitrous -gas, a small piece of charcoal which had been just reddened. The sun -being very bright, the focus of the lens was kept on it for rather more -than an hour and quarter. In the middle of the process it began to fume -and to sparkle, as if in combustion. In three quarters of an hour, the -gas was increased rather more than half a measure; but no alteration of -volume took place afterwards.</p> - -<p>The mercury was not white on the top as is usually the case when -nitrous acid is produced. On introducing into the cylinder a little -pale green sulphate of iron, and then adding prussiate of potash, a -white precipitate only was produced. Now, if the minutest quantity of -nitric acid had been formed, it would have been decomposed by the pale -green oxide of iron, and hence, a visible quantity of prussian blue<a id="FNanchor_102" href="#Footnote_102" class="fnanchor">[102]</a> -produced, as will be fully explained hereafter. -<span class="pagenum" id="Page_132">[Pg 132]</span></p> - -<p id="RI_DIV_03" class="f120 space-above1">III. <i>Analysis of Nitrous Gas by Pyrophorus.</i></p> - -<p>I placed some newly made pyrophorus, about as much as would fill a -quarter of a cubic inch, in a jar filled with dry mercury, and -introduced to it, four cubic inches of nitrous gas, procured from -mercury and nitric acid.</p> - -<p>It instantly took fire and burnt with great vividness for some moments.</p> - -<p>After the combustion had ceased, the gas was diminished about three -quarters of a cubic inch. The remainder was not examined; for the -diminution appeared to go on for some time, after; in an half hour, -when it was compleat, it was to 2 cubic inches. A taper, introduced -into these, burnt with an enlarged flame, blue at the edges; from -whence it appeared, that they were composed of nitrogene and nitrous -oxide.</p> - -<p>I now introduced about half a cubic inch of pyrophorus to two cubic -inches of nitrous gas; the combustion took place, and the gas was -<span class="pagenum" id="Page_133">[Pg 133]</span> -rapidly diminished to one half; and on suffering it to remain five -minutes to one third nearly; which extinguished flame.</p> - -<p>Suspecting that this great diminution was owing to the absorption of -some of the nitrogene formed, by the charcoal of the pyrophorus, I -carefully made a quantity of pyrophorus; employing more than two thirds -of alumn, to one third of sugar.</p> - -<p>To rather more than half of a cubic inch of this, two cubic inches of -nitrous gas, which contained about ¹/₄₀ nitrogene, were admitted. After -the combustion, the gas remaining, <i>apparently</i> filled a space -equal to 1,2 cubic inches; but, as on account of the burnt pyrophyrus -in the jar, it was impossible to ascertain the volume with nicety, it -was carefully and wholly transferred into another jar. It filled a -space equal to 1,15 cubic inches nearly.</p> - -<p>When water was admitted to this gas no absorption took place. It -underwent no diminution with nitrous gas, and a taper plunged into it -was instantly extinguished. We may consequently conclude that it was -nitrogene. -<span class="pagenum" id="Page_134">[Pg 134]</span></p> - -<p>Now 2 cubic inches of nitrous gas weigh,686 grains, and 1,1 of -nitrogene—,05, the quantity previously contained in the gas = to 1,05, -3,19. Hence,686 of nitrous gas would be composed of,367 oxygene, and -,319 nitrogene; and 100 grains would contain 53,4 oxygene, and 46,6 nitrogene.</p> - -<p id="RI_DIV_04" class="f120 space-above1">IV. <i>Additional observations -on the combustion of bodies in Nitrous Gas,<br /> and on its Composition.</i></p> - -<p>Though phosphorus may be fused, and even sublimed, in nitrous gas, -without producing the slightest luminous appearance,<a id="FNanchor_103" href="#Footnote_103" class="fnanchor">[103]</a> -yet when it is introduced into it in a state of active inflammation, it burns with -<span class="pagenum" id="Page_135">[Pg 135]</span> -almost as much vividness as in oxygene.<a id="FNanchor_104" href="#Footnote_104" class="fnanchor">[104]</a> -Hence it is evident, that at the heat of ignition, phosphorus is capable -of attracting the oxygene from the nitrogene of nitrous gas.</p> - -<p>I attempted to analise nitrous gas, by introducing into a known -quantity of it, confined by mercury, phosphorus, in a vessel containing -a minute quantity of oxygene.<a id="FNanchor_105" href="#Footnote_105" class="fnanchor">[105]</a> -The phosphorus was inflamed with an ignited iron wire, by which, at the -moment of the combustion, the vessel containing it was raised from the -mercury into the nitrous gas. But after making in this way, five of six -unsuccessful experiments, I desisted. When the communication between -<span class="pagenum" id="Page_136">[Pg 136]</span> -the vessels was made before the oxygene was nearly combined with -the phosphorus, nitrous acid was formed, which instantly destroyed -the combustion; when, on the contrary, the phosphorus was suffered -to consume almost the whole of the oxygene, it was not sufficiently -ignited when introduced, to decompose the nitrous gas.</p> - -<p>In one experiment, indeed, the phosphorus burnt for a moment in the -nitrous gas; the diminution however was slight, and not more than ¼ of -it was decomposed.</p> - -<p>Sulphur, introduced in a state of vivid inflammation, into nitrous gas, -was instantly extinguished.</p> - -<p>I passed a strong electric shock through equal parts of hydrogene -and nitrous gas, confined by mercury in a detonating tube; but no -inflammation, or perceptible diminution, was produced.</p> - -<p>19,2 grain measures of hydrogene were fired by the electric shock, -with 10 of nitrous oxide, and 6 of nitrous gas; the diminution was to -17; and pale green sulphate of iron admitted to the residuum, was not -<span class="pagenum" id="Page_137">[Pg 137]</span> -discolored. Consequently the nitrous gas was decomposed by the -hydrogene, and as will be hereafter more clearly understood, nearly as -much nitrogene furnished by it, as would have been produced from half -the quantity of nitrous oxide.</p> - -<p>Suspecting that phosphorated hydrogene might inflame with nitrous -gas, I passed the electric spark through 1 measure of phosphorated -hydrogene, and 4 of nitrous gas; but no diminution was perceptible. I -likewise passed the electric spark through 1 of nitrous gas, with 2 of -phosphorated hydrogene, without inflammation.</p> - -<p>Perhaps if I had tried many other different proportions of the gases, I -should have at last discovered one, in which they would have inflamed; -for, as will be seen hereafter, nitrous oxide cannot be decomposed by -the compound combustible gases, except definite quantities are employed.</p> - -<p>From Dr. Priestley’s experiments on iron and pyrophorus, and from the -experiments I have detailed, on charcoal, phosphorus, and hydrogene, it -<span class="pagenum" id="Page_138">[Pg 138]</span> -appears that at certain temperatures, nitrous gas is decomposable by -most of the combustible bodies: even the extinction of sulphur, when -introduced into it in a state of inflammation, depends perhaps, on the -smaller quantity of heat produced by the combustion of this body, than -that of most others.</p> - -<p>The analysis of nitrous gas by charcoal, as affording data for -determining immediately the quantities of oxygene and nitrogene, -ought to be considered as most accurate; and correcting it by mean -calculations derived from the decomposition of nitrous gas by -pyrophorus and hydrogene, and its conversion into nitrous oxide, a -process to be described hereafter, we may conclude, that 100 grains -of nitrous gas are composed of 55,95 oxygene, and 44,05 nitrogene; or -taking away decimals, of 56 oxygene, and 44 nitrogene.</p> - -<p>This estimation will agree very well with the mean proportions that -would be given from Dr. Priestley’s experiments on the decomposition of -<span class="pagenum" id="Page_139">[Pg 139]</span> -nitrous gas by iron; but as he never ascertained the purity of his -nitrous gas,<a id="FNanchor_106" href="#Footnote_106" class="fnanchor">[106]</a> -and probably employed different kinds in different experiments, it is -impossible to fix on any one, from which accurate conclusions can be drawn.</p> - -<p>Lavoisier’s estimation of the quantities of oxygene and nitrogene -entering into the composition of nitrous gas, has been generally -adopted. He supposes 64 parts of nitrous gas to be composed of 43½ of -oxygene, and 20½ of nitrogene.<a id="FNanchor_107" href="#Footnote_107" class="fnanchor">[107]</a></p> - -<p>The difference between this account and mine is very great indeed; -but I have already, in <a href="#RI_DIV_I">Division 1st</a>, pointed -out sources of error in the experiments of this great man, on the -decomposition of nitre by charcoal; which experiments were fundamental, -both to his accounts of the constitution of nitrous acid, and nitrous gas. -<span class="pagenum" id="Page_140">[Pg 140]</span></p> - -<p id="RI_DIV_05" class="f120 space-above1">V. <i>Of the absorption -of Nitrous Gas by Water.</i></p> - -<p>Amongst the properties of nitrous gas noticed by its great discoverer, -is that of absorbability by water.</p> - -<p>In exposing nitrous air to distilled water, Dr. Priestley found a -diminution of the volume of gas, nearly equal to one tenth of the bulk -of the water; and by boiling the water thus impregnated, he procured -again a certain portion of the nitrous gas.</p> - -<p>Humbolt, in his paper on eudiometry, mentions the diminution of -nitrous gas by water. This diminution, he supposes to arise from the -decomposition of a portion of the nitrous gas, by the water, and the -consequent formation of nitrate of ammoniac.<a id="FNanchor_108" href="#Footnote_108" class="fnanchor">[108]</a></p> - -<p><span class="pagenum" id="Page_141">[Pg 141]</span> -I confess, that even before the following experiments were made, I -was but little inclined to adopt this opinion: the small diminution -of nitrous gas by water, and the uniform limits of this diminution, -rendered it extremely improbable. -<span class="pagenum" id="Page_142">[Pg 142]</span></p> - -<p><i>a.</i> To ascertain the quantity of nitrous gas absorbable by pure -water, and the limits of absorption, I introduced into a glass retort -about 5 ounces of water, which had been previously boiled for some -hours. The neck of the retort was inverted in mercury, and the water -made to boil. After a third of it had been distilled, so that no air -could possibly remain in the retort, the remainder was driven over, -and condensed in an inverted jar filled with mercury. To three cubic -inches of this water,<a id="FNanchor_109" href="#Footnote_109" class="fnanchor">[109]</a> -confined in a cylinder graduated to,05 cubic inches, 5 cubic inches -of nitrous gas, containing nearly one thirtieth nitrogene, were -introduced.</p> - -<p>After agitation for near an hour, rather more than ⁴/₂₀ of a cubic inch -appeared to be absorbed; but though the process was continued for near -two hours longer, no further diminution took place.</p> - -<p>The remaining gas was introduced into a tube graduated to,02 cubic -inches. It measured ¹⁴/₅₀; hence ¹¹/₅₀ had been absorbed. -<span class="pagenum" id="Page_143">[Pg 143]</span></p> - -<p>Consequently, 100 cubic inches of pure water are capable of absorbing -11,8 of nitrous gas. In the water thus impregnated with nitrous gas I -could distinguish no peculiar taste;<a id="FNanchor_110" href="#Footnote_110" class="fnanchor">[110]</a> -it did not at all alter the color of blue cabbage juice.</p> - -<p><i>b.</i> To determine if the absorption of nitrous gas was owing, to -a decomposition of it by the water, as Humbolt has supposed, or to a -simple solution; I procured some nitrous gas from nitrous acid and -mercury, containing about one seventieth nitrogene. ,5 cubic inches -of it, mingled with ,25, of oxygene, from sulphuric acid and manganese -left a residuum of,03. 5 cubic inches more were introduced to 3 of -water, procured in the same manner as in the last experiment, in the -same cylinder.<span class="pagenum" id="Page_144">[Pg 144]</span> -After the diminution was complete, the cylinder was transferred in a -small vessel containing mercury, into a water bath, and nearly covered -by the water.</p> - -<p>As the bath was heated, small globules of gas were given out from the -impregnated water, and when it began to boil, the production of gas was -still more rapid. After an hour’s ebullition, the volume of heated gas -was equal to 1,4 cubic inches nearly.</p> - -<p>The cylinder was now taken out of the bath, and quickly rendered cool -by being placed in a water apparatus. At the common temperature the gas -occupied, as nearly as possible, the space of,5 cubic inches: these,5 -mingled with,25 of oxygene, of the same kind as that employed before, -left a residuum nearly equal to,03.</p> - -<p>From this experiment, which was repeated with nearly the same results, -it is evident,</p> - -<div class="blockquot"> -<p>1. That nitrous gas is not decomposable by pure water.</p> - -<p>2. That the diminution of volume of nitrous gas placed -in contact with water, is owing to a simple solution -<span class="pagenum" id="Page_145">[Pg 145]</span> -of it in that fluid.</p> - -<p>3. That at the temperature of 212°, nitrous gas is -incapable of remaining in combination with water.</p> -</div> - -<p>Humbolt’s opinion relating to the decomposition of nitrous gas by -water, is founded upon the disengagement of vapor from distilled water -impregnated with nitrous gas, by means of lime, which became white in -the proximity of the muriatic acid. But this is a very imperfect, and -fallacious test, of the presence of ammoniac. I have this day, April -2, 1800, heated 4 cubic inches of distilled water, impregnated with -nitrous gas, with caustic lime; the vapor certainly became a little -whiter when held over a vessel containing muriatic acid; but the vapor -of distilled water produced precisely the same appearance,<a id="FNanchor_111" href="#Footnote_111" class="fnanchor">[111]</a> -<span class="pagenum" id="Page_146">[Pg 146]</span> -which was owing, most likely, to the combination of the acid with the -aqueous vapor. Indeed, when I added a particle of nitrate of ammoniac, -which might have equalled one twentieth of a grain, to the lime and -impregnated water, the increased whiteness of the vapor was but barely -perceptible, though this quantity of nitrate of ammoniac is much more -considerable than that which could have been formed, even supposing the -nitrous gas decomposed.</p> - -<p id="RI_DIV_06" class="f120 space-above1">VI. <i>Of the absorption -of Nitrous Gas by<br /> Water of different kinds.</i></p> - -<p>In agitating nitrous gas over spring water, the diminution rarely -amounts to more than one thirtieth, the volume of water being taken as -<span class="pagenum" id="Page_147">[Pg 147]</span> -unity. I at first suspected that this great differcnce in the quantity -of gas absorbed by spring water, and pure water, depended on carbonic -acid contained in the last, diminishing the attraction of it for -nitrous gas: but by long boiling a quantity of spring water confined -by mercury, I obtained from it about one twentieth of its bulk of air, -which gave nearly the same diminution with nitrous gas, as atmospheric air.</p> - -<p>This fact induced me to refer the difference of diminution to the -decomposition of the atmospheric air held in solution by the water, -the oxygene of which I supposed to be converted into nitric acid, by -the nitrous gas, whilst the nitrogene was liberated; and hence the -increased residuum.</p> - -<p><i>a.</i> I exposed to pure water, that is, water procured by -distillation under mercury, nitrous gas, containing a known quantity of -nitrogene. After the absorption was complete, I found the same quantity -of nitrogene in the residuum, as was contained in a volume of gas equal -to the whole quantity employed. -<span class="pagenum" id="Page_148">[Pg 148]</span></p> - -<p><i>b.</i> Spring water boiled for some hours, and suffered to cool -under mercury, absorbed a quantity of nitrous gas equal to one -thirteenth of its bulk; which is not much less than that absorbed by -pure water.</p> - -<p><i>c.</i> I exposed to spring water, 10 measures of nitrous gas; the -composition of which had been accurately ascertained; the diminution -was one twenty-eighth, the volume of water being taken as unity. On -placing the residuum in contact with solution of sulphate of iron, -the nitrogene remaining was nearly one twentieth more than had been -contained by the gas before its exposure to water.</p> - -<p><i>d.</i> Distilled water was saturated with common air, by being -agitated for some time in the atmosphere. Nitrous gas placed in contact -with this water, underwent a diminution of ¹/₁₈; the volume of water -being unity. The gas remaining after the absorption contained about one -twenty-seventh nitrogene more than before. -<span class="pagenum" id="Page_149">[Pg 149]</span></p> - -<p><i>e.</i> Nitrous gas exposed to water combined with about one fourth -of its volume of carbonic acid, diminished to ¹/₃₂<a id="FNanchor_112" href="#Footnote_112" class="fnanchor">[112]</a> -nearly. The remainder contained little or no superabundant nitrogene.</p> - -<p>From these observations it appears, that the different degrees of -diminution of nitrous gas by different kinds of water, may depend upon -various causes.</p> - -<p>1. Less nitrous gas will be absorbed by water holding in solution -earthy salts, than by pure water; and in this case the diminution of -the attraction of water for nitrous gas will probably be in the ratio -of the quantities of salt combined with it. <i>a.</i> <i>b.</i></p> - -<p>2. The apparent diminution of nitrous gas in water, holding in solution -atmospheric air, will be less than in pure water, though the absolute -diminution will be greater; for the same portion will be absorbed, -whilst another portion is combined with the oxygene of the atmospheric -<span class="pagenum" id="Page_150">[Pg 150]</span> -air contained in the water; and from the disengagement of the nitrogene -of this air, arises an increased residuum. <i>c.</i> <i>d.</i></p> - -<p>3. Probably in waters containing nitrogene, hydrogene, and other gases, -absorbable only to a slight extent, the apparent diminution will be -less, on account of the disengagement of those gases from the water, by -the stronger affinity of nitrous gas for that fluid.</p> - -<p>4. In water containing carbonic acid, and probably some other acid -gases, the diminution will be small in proportion to the quantity of -gas contained in the water: the affinity of this fluid for nitrous gas -being diminished by its greater affinity for the substance combined -with it. <i>e.</i></p> - -<p>The different diminution of nitrous gas when agitated in different -kinds of water, has been long observed by experimenters on the -constituent parts of the atmosphere, and various solutions have been -given of the phænomenon; the most singular is that of Humbolt.<a id="FNanchor_113" href="#Footnote_113" class="fnanchor">[113]</a> -<span class="pagenum" id="Page_151">[Pg 151]</span> -He supposes that the apparent diminution of nitrous gas is less in spring -water than distilled water, on account of the decomposition of the -carbonate of lime contained in the spring water, by the nitrous acid -formed from the contact of nitrous gas with the water; the carbonic -acid disengaged from this decomposition increasing the residuum.</p> - -<p>This opinion may be confuted without even reference to my observations. -<span class="pagenum" id="Page_152">[Pg 152]</span> -It is, indeed, altogether unworthy of a philosopher, generally acute -and ingenious. He seems to have forgotten that carbonic acid is -absorbable by water.</p> - -<p id="RI_DIV_07" class="f120 space-above1">VII. <i>Of the absorption of -Nitrous Gas, by solution<br /> of pale green Sulphate of Iron.</i></p> - -<p><i>a.</i> The discovery of the exact difference between the sulphates -of iron, is owing to Proust.<a id="FNanchor_114" href="#Footnote_114" class="fnanchor">[114]</a> -According to the ingenious researches of this chemist, there exist -two varieties of sulphate of iron, the green and the red. The oxide -in the green sulphate contains ²⁷/₁₀₀ oxygen. This salt, when pure, -is insoluble in spirit of wine; its solution in water is of a pale -green color; it is not altered by the gallic acid, and affords a white -precipitate with alkaline prussiates.</p> - -<p>The red sulphate of iron is soluble in alcohol and uncrystalizable; its -oxide contains ⁴⁸/₁₀₀ oxygene. It forms a black precipitate with the -gallic acid, and with the alkaline prussiates, a blue one. -<span class="pagenum" id="Page_153">[Pg 153]</span></p> - -<p>The common sulphates of iron generally consist of combinations of these -two varieties in different proportions.</p> - -<p>The green sulphate may be converted into the red by oxygenated muriatic -acid or nitric acid. The common sulphate may be converted into green -sulphate, by agitation in contact with sulphurated hydrogene.</p> - -<p>The green sulphate has a strong affinity for oxygene, it attracts it -from the atmosphere, from oxygenated marine acid, and nitric acid. The -alkalies precipitate from it a pale green oxide, which if exposed to -the atmosphere, rapidly becomes yellow red.</p> - -<p>The red sulphate of iron has no affinity for oxygene, and when -decomposed by the alkalies, gives a red precipitate, which undergoes no -alteration when exposed to the atmosphere.<a id="FNanchor_115" href="#Footnote_115" class="fnanchor">[115]</a></p> - -<p><i>b.</i> The absorption of nitrous gas by a solution of sulphate of -<span class="pagenum" id="Page_154">[Pg 154]</span> -iron, was long ago discovered by Priestley. During this absorption, he -remarked a change of color in the solution, analogous to that produced -by the mixture of it with nitric acid.</p> - -<p>This chemical fact has been lately applied by Humbolt, to the discovery -of the nitrogene generally mingled with nitrous gas.</p> - -<p>Vauquelin and Humbolt have published a memoir, on the causes of the -absorption<a id="FNanchor_116" href="#Footnote_116" class="fnanchor">[116]</a> -of nitrous gas by solution of sulphate of iron. They -saturated an ounce and half of sulphate of iron in solution, with 180 -cubic inches of nitrous gas.</p> - -<p>Thus impregnated it strongly reddened tincture of turnsoyle; when -mingled with sulphuric acid, gave nitric acid vapor; and saturated with -potash, ammoniacal vapor.</p> - -<p>By analysis, it produced as much ammoniac as that contained in 4 grains -of ammoniacal muriate, and a quantity of nitric acid equal to that -<span class="pagenum" id="Page_155">[Pg 155]</span> -existing in 17 grains of nitre. Hence they concluded, that the nitrous -gas and a portion of the water of the solution, had mutually decomposed -each other; the oxygene of the water combining with the oxygene and a -portion of the nitrogene of nitrous gas to form nitric acid; and its -hydrogene uniting with the remaining nitrogene, to generate ammoniac.</p> - -<p>They have taken no notice of the nature of the sulphate of iron -employed, which was most probably the common or mixed sulphate; nor of -the attraction of the oxide of iron in this substance for oxygene.</p> - -<p><i>c.</i> Before I was acquainted with the observations of Proust, the -common facts relating to the oxygenation of vitriol of iron induced -me to suppose, that the attraction of this substance for oxygene was -in some way connected with the process of absorption. The comparison -of the experiments of Humbolt and Vauquelin, with the observations of -Proust, enabled me to discover the true nature of the process.</p> - -<p>I procured a solution of red sulphate of iron, by passing oxygenated -<span class="pagenum" id="Page_156">[Pg 156]</span> -muriatic acid through a solution of common sulphate of iron, till it -gave only a red precipitate, when mingled with caustic potash. To -nitrous gas confined by mercury, a small quantity of this solution was -introduced. On agitation, its color altered to muddy green; but the -absorption that took place was extremely trifling: in half an hour it -did not amount to,2, the volume of the solution being unity, when it -had nearly regained the yellow color.</p> - -<p>I now obtained a solution of green sulphate of iron, by dissolving iron -filings in diluted sulphuric acid. The solution was agitated in contact -with sulphurated hydrogene, and afterwards boiled; when it gave a white -precipitate with prussiate of potash.</p> - -<p>A small quantity of this solution agitated in nitrous gas, quickly -became of an olive brown, and the gas was diminished with great -rapidity; in two minutes, a quantity equal to four times the volume of -the solution, had been absorbed.</p> - -<p>These facts convinced me that the solubility of nitrous gas in common -<span class="pagenum" id="Page_157">[Pg 157]</span> -sulphate of iron, chiefly depended upon the pale green sulphate -contained by it; and that the attraction of one of the constituents of -this substance, the green oxide of iron, for oxygene, was one of the -causes of the phænomenon.</p> - -<p><i>d.</i> Green sulphate of iron rapidly decomposes nitric acid. It was -consequently difficult to conceive how any affinities existing between -nitrous gas, water, and green sulphate of iron, could produce the -nitric acid found in the experiments of Vauquelin and Humbolt.</p> - -<p>To ascertain if the presence of a great quantity of water destroyed the -power of green sulphate of iron to decompose nitric acid, I introduced -into a cubic inch of solution of green sulphate of iron, two drops of -concentrated nitric acid.</p> - -<p>The solution assumed a very light olive color; prussiate of potash -mingled with a little of it, gave a dark green precipitate. Hence the -nitric acid had been evidently decomposed. As no nitrous gas was given -<span class="pagenum" id="Page_158">[Pg 158]</span> -out, which is always the case when nitric acid is poured on crystalised -sulphate of iron, I suspected that a compleat decomposition of the -acid had taken place; but when the solution was heated, a few minute -globules of gas were liberated, and it gradually became slightly clouded.</p> - -<p>Having often remarked that no precipitation is ever produced during the -conversion of green sulphate of iron into red, by oxygenated muriatic -acid, or concentrated nitric acid, I could refer the cloudiness to no -other cause than to the formation of ammoniac.</p> - -<p>To ascertain if this substance had been produced, a quantity of slacked -caustic lime was thrown into the solution. On the application of heat, -the ammoniacal smell was distinctly perceptible, and the vapor held -over orange nitrous acid, gave dense white fumes.</p> - -<p><i>e.</i> When I considered this fact of the decomposition of nitric -acid and water by the solution of green sulphate of iron, and the -change of color effected in it by the absorption of nitrous gas, -exactly analogous to that produced by the decomposition of nitric acid; -<span class="pagenum" id="Page_159">[Pg 159]</span> -I was induced to believe that the nitric acid found in the analysis -of Vauquelin and Humbolt, had been formed by the combination of some -of the nitrous gas thrown into the solution with the oxygene of the -atmosphere: and that the absorbability of nitrous gas, by solution of -green sulphate of iron, was owing to a decomposition produced by the -combination of its oxygene with the green oxide of iron, and of its -nitrogene with the hydrogene disengaged from water, decompounded at -the same time.</p> - -<p>To ascertain this, I procured a quantity of nitrous gas: it was -suffered to remain in contact with water for some hours after its -production. Transferred to the mercurial apparatus, it gave no -white vapor when placed in contact with solution of ammoniac; and -consequently held no nitric acid in solution.</p> - -<p>Into a graduated jar filled with mercury, a cubic inch of concentrated -solution of pure green sulphate of iron was introduced, and 7 cubic -inches of nitrous gas admitted to it. The solution immediately became -<span class="pagenum" id="Page_160">[Pg 160]</span> -dark olive at the edges, and on agitation this color was diffused -through it. In 3 minutes, when near 5¾ cubic inches had been absorbed, -the diminution ceased. The solution was now of a bright olive brown, -and transparent at the edges. After it had rested for a quarter of an -hour, no farther absorption was observed; the color was the same, and -no precipitation could be perceived. A little of it was thrown into a -small glass tube, under the mercury, and examined in the atmosphere. -Its taste was rather more astringent than that of solution of green -sulphate; it did not at all alter the color of red cabbage juice. When -a little of it was poured on the mercury, it soon lost its color, its -taste became acid, and it quickly reddened cabbage juice, even rendered -green by an alkali.</p> - -<p>To the solution remaining in the mercurial jar, a small quantity of -prussiate of potash was introduced, to ascertain if any red sulphate of -iron had been formed; but instead of the production of either a blue, -or a white precipitate, the whole of the solution became opaque, and -chocolate colored. -<span class="pagenum" id="Page_161">[Pg 161]</span></p> - -<p>Surprised at this appearance, I was at first induced to suppose, -that the ammoniac formed by the nitrogene of the nitrous gas and the -hydrogene of the water, had been sufficient to precipitate from the -sulphuric acid, the red oxide of iron produced, and that the color of -the mixture was owing to this precipitation. To dissolve any uncombined -oxide that might exist in the solution, I added a very minute quantity -of diluted sulphuric acid; but little alteration of color was produced. -Hence, evidently, no red oxide had been formed.</p> - -<p>This unexpected result obliged me to theorise a second time, -by supposing that nitrate of ammoniac had been produced, which -by combining with the white prussiate of iron, generated a new -combination. But on mingling together green sulphate of iron, prussiate -of potash, and nitrate of ammoniac in the atmosphere, the mixture -remained perfectly white.</p> - -<p>To ascertain if any nitric acid existed, combined with any of the -bases, in the impregnated solution, I introduced into it an equal bulk -<span class="pagenum" id="Page_162">[Pg 162]</span> -of diluted sulphuric acid: it became rather paler; but no green or blue -tinge was produced.</p> - -<p>That the prussic acid had not been decomposed, was evident from the -bright green produced, when less than a grain of dilute nitric acid was -admitted into the solution.</p> - -<p><i>f.</i> From these experiments it was evident, that no red sulphate -of iron, or nitric acid, and consequently no ammoniac, had been -produced after the absorption of nitrous gas by green sulphate of iron. -And when I compared them with the observations of Priestley, who had -expelled by heat a minute quantity of nitrous gas from an impregnated -solution of common sulphate of iron, and who found common air -phlogisticated by standing in contact with it, I began to suspect that -nitrous gas was simply dissolved in the solution, without undergoing -decomposition.</p> - -<p><i>g.</i> To determine more accurately the nature of the process, I -introduced into a mercurial cylinder 410 grains of solution of green -<span class="pagenum" id="Page_163">[Pg 163]</span> -sulphate of iron, occupying a space nearly equal to a cubic inch and -quarter; it was saturated with nitrous gas, by absorbing 8 cubic -inches. This saturated solution exhibited the same appearance as -the last; and after remaining near an hour untouched, had evidently -deposited no oxide of iron, nor gained any acid properties.</p> - -<p>Into a small mattrass filled with mercury, having a tight stopper -with a curved tube adapted to it, the greater part of this solution -was introduced; judging from the capacity of the mattrass, about 50 -grains of it might have been lost. To prevent common air from coming in -contact with the solution, the stopper was introduced into the mattrass -under the mercury; the curved tube connected with a graduated cylinder -filled with that substance; and the mattrass brought over the side of -the mercurial trough. But in spite of these precautions a large globule -of common air got into the top of the mattrass, from the curvature of -the tube. When the heat of a spirit lamp was applied to the solution, -it gave out gas with great rapidity, and gradually lost its color. When -<span class="pagenum" id="Page_164">[Pg 164]</span> -5 cubic inches were collected it became perfectly pale green, whilst a -yellow red precipitate was deposited on the bottom of the mattrass.</p> - -<p>On pouring a little of the clear solution into prussiate of potash, it -gave only white prussiate of iron.</p> - -<p>But on introducing a particle of sulphuric acid into the solution, -sufficient to dissolve some of the red precipitate, and then pouring -a little of it into a solution of prussiate of potash, it gave a fine -blue prussiate of iron.</p> - -<p>Hence the red precipitate was evidently red yellow oxide of iron.</p> - -<p>I now examined the gas, suspecting that it was nitrous oxide. On -mingling a little of it with atmospheric air, it gave red vapor, and -diminished. Solution of sulphate of iron introduced to the remainder, -almost wholly absorbed it: the small residual globule of nitrogene -could not equal one thirtieth of a cubic inch.</p> - -<p>Consequently it was nitrous gas, nearly pure.</p> - -<p>Caustic potash was now introduced into the solution, till all the -oxide of iron was precipitated. The solution, when heated, gave a strong -<span class="pagenum" id="Page_165">[Pg 165]</span> -smell of ammoniac, and dense white fumes when held over muriatic acid. -It was kept at the heat of ebullition till the evaporation had been -nearly compleated. Sulphuric acid poured upon the residuum gave no -yellow fumes, or nitric acid vapor in any way perceptible; even when -heated and made to boil, there was no indication of the production of -any vapor, except that of the sulphuric acid.</p> - -<p><i>h.</i> This experiment, compared with the others, seemed almost to -prove, that nitrous gas combined with solution of pale green sulphate -of iron, at the common temperature, without decomposition; and that -when the impregnated solution was heated, the greater portion of gas -was disengaged, whilst the remainder was decompounded by the green -oxide of iron; which attracted at the same time oxygene from the -water and the nitrous gas; whilst their other constituent principles, -hydrogene and nitrogene, entered into union as ammoniac.</p> - -<p>Whilst, however, I was reasoning upon this singular chemical change, -<span class="pagenum" id="Page_166">[Pg 166]</span> -as affording presumptive proofs in favor of the exertion of simple -affinities by the constituent parts of compound substances, a doubt -concerning the decomposition of the nitrous gas occurred to me. As -near as I could guess at the quantity of nitrous gas contained by -the impregnated solution, at least ¾ of it must have been expelled -undecompounded.</p> - -<p>More than a quarter of a cubic inch of common air had been present in -the mattrass: the oxygene of this common air must have combined with -the nitrous gas, to form nitric acid. Might not this nitric acid have -been decomposed, and furnished oxygene to the red oxide of iron, and -nitrogene to the small quantity of ammoniac found in the solution, as -in <i>d</i>?</p> - -<p><i>i.</i> I now introduced to a solution of green sulphate confined -by mercury, nitrous gas, perfectly free from nitric acid. When the -solution was saturated, a portion of it was introduced into a small -mattrass filled with dry mercury, in the mercurial trough. The curved -<span class="pagenum" id="Page_167">[Pg 167]</span> -tube was closed by a small cork at the top, and filled with nitrous -gas; it was then adapted to the mattrass, which was raised from the -trough, and the solution thus effectually preserved from the contact of -the atmosphere.</p> - -<p>When the heat of a spirit lamp was applied to the mattrass, it began to -give out gas with great rapidity. After some time the solution lost its -dark color, and became turbid. When the production of nitrous gas had -ceased, it was suffered to cool. A copious red precipitate had fallen -down; which, examined by the same tests as in the last experiment, -proved to be red oxide of iron.</p> - -<p>The solution treated with lime, as before, gave ammoniac; but with -sulphuric acid, not the slightest indications of nitric acid.</p> - -<p><i>k.</i> Having thus procured full evidence of the decomposition of -nitrous gas in the heated solution, in order to gain a more accurate -acquaintance with the affinities exerted, I endeavoured to ascertain -the quantity of nitrous gas decomposed by a given solution, under known -circumstances. -<span class="pagenum" id="Page_168">[Pg 168]</span></p> - -<p>Into a cylinder of the capacity of 20 cubic inches, inverted in -mercury, 1150 grains of solution of green sulphate of iron, of specific -gravity 1,4, were introduced. Nitrous gas was admitted to it, and after -some time 21 cubic inches were absorbed.</p> - -<p>The impregnated solution was thrown into a mattrass, in the same manner -as in the last experiment, and the same precautions taken to preserve -it from the contact of atmospheric air. A quantity was lost during -the process of transferring, which, reasoning from the space occupied -in the mattrass by the remaining portion, as determined by experiment -afterwards, must have amounted nearly to 240 grains.</p> - -<p>The curved tube from the mattrass was now made to communicate with the -mercurial airholder. By the application of heat 12,5 cubic inches -of nitrous gas were collected, after the common temperature had been -restored to the mattrass; which was suffered to remain in communication -with the conducting tube. -<span class="pagenum" id="Page_169">[Pg 169]</span></p> - -<p>The solution was now pale green, that is, of its natural color, and a -considerable quantity of red oxide of iron had been deposited.</p> - -<p>Solid caustic potash was introduced into it, till all the green oxide -of iron had been precipitated, and till the solution rendered green, -red cabbage juice.</p> - -<p>A tube was now accurately connected with the mattrass, bent, and -introduced into a small quantity of diluted sulphuric acid. Nearly half -of the fluid in it was slowly distilled into the sulphuric acid, by -the heat of a spirit lamp. The impregnated acid evaporated at a heat -above 212°, and gave a small quantity of crystalised salt, which barely -amounted to two grains and quarter: it had every property of sulphate -of ammoniac. Sulphuric acid in excess was poured on the residuum, and -the whole distilled by a heat not exceeding 300°, into a small quantity -of water. This water, after the process, tasted strongly of sulphuric -acid; it had no peculiar odor. Tin thrown into it when heated, was not -perceptibly oxydated; mingled with strontitic lime water, it gave a -<span class="pagenum" id="Page_170">[Pg 170]</span> -copious white precipitate, and after the precipitation became almost -tasteless. Hence it evidently contained no nitric acid.</p> - -<p>The 12,5 cubic inches of undecompounded gas that came over were -examined; and accounting for the small quantity of common air -previously contained in the airholder, must have been almost pure.</p> - -<p><i>l.</i> Now supposing 927 grains of the impregnated solution -(including the weight of the nitrous gas), to have been operated upon, -this must have contained about 16,7 cubic inches of nitrous gas. But -12,5 cubic inches escaped undecompounded: hence 4,2 were decomposed; -and these weigh 1,44 grains, and are composed of,8 oxygene, and,64 -nitrogene.<a id="FNanchor_117" href="#Footnote_117" class="fnanchor">[117]</a></p> - -<p>Consequently, the nitrous gas must have furnished,8 of oxygene to the -green oxide of iron.</p> - -<p>But,64 of nitrogene require,15 of hydrogene to form,79 of -ammoniac:<a id="FNanchor_118" href="#Footnote_118" class="fnanchor">[118]</a> -consequently 1 of water was decompounded, and this furnished,85 of -oxygene to the green oxide of iron. -<span class="pagenum" id="Page_171">[Pg 171]</span></p> - -<p>The green oxide of iron contains ²⁷/₁₀₀ oxygene; the red ⁴⁸/₁₀₀. But -the whole quantity of oxygene supplied from the water and nitrous -gas is 0,8 + 0,85 = 1,65; and calculating on the difference of the -composition of the red and green oxide of iron, 5,7 grains of red oxide -must have been deposited, and consequently these would saturate as much -acid as,79 grains of ammoniac, or 4,1 grains of green oxide of iron.<a id="FNanchor_119" href="#Footnote_119" class="fnanchor">[119]</a></p> - -<p>And supposing the ammoniac in sulphate of ammoniac to be to the acid as -1 is to 3,<a id="FNanchor_120" href="#Footnote_120" class="fnanchor">[120]</a> -3.2 grains of sulphate of ammoniac must have been formed, -containing about 2,4 grains acid; and then 6,5 grains of green -sulphate of iron must have been decomposed. -<span class="pagenum" id="Page_172">[Pg 172]</span></p> - -<p>Hence we gain the following equation:</p> - -<table border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdr">6,5 green s.</td> - <td class="tdl_ws1">= 2,41 sul. acid + 4,1 gr. ox. iron.</td> - </tr><tr> - <td class="tdc" colspan="2"><big>+</big></td> - </tr><tr> - <td class="tdr">1,44 nit. gas</td> - <td class="tdl_ws1">= ,64 nitrogene + ,8 oxygene.</td> - </tr><tr> - <td class="tdc" colspan="2"><big>+</big></td> - </tr><tr> - <td class="tdl">1 water</td> - <td class="tdl_ws1">= ,85 oxygene, + ,15 hydrogene,</td> - </tr><tr> - <td class="tdc" colspan="2"><br /><big>equal</big><br /> </td> - </tr><tr> - <td class="tdl">3,2 sul. am.</td> - <td class="tdl_ws1">= 2,41 s. acid + ,64 nit. + ,15 hyd.</td> - </tr><tr> - <td class="tdc" colspan="2"><big>+</big></td> - </tr><tr> - <td class="tdl">5,7 r. ox. iron</td> - <td class="tdl_ws1">= 4,1 gr. ox. iron + 1,6 oxyg.</td> - </tr> - </tbody> -</table> - -<p>Though the estimation of the quantities in this equation must not -be considered as strictly accurate, on account of the degree of -uncertainty that remains concerning the exact numerical expression of -the quantities of the constituents of water, ammoniac, and the other -compound bodies employed; yet as founded on a simple quantity, that is, -the nitrous gas decomposed, it cannot be very distant from the truth.</p> - -<p>The sulphate of ammoniac given by experiment, is considerably less -than that which was really produced; much of it was probably carried -off during the evaporation of the superabundant acid. -<span class="pagenum" id="Page_173">[Pg 173]</span></p> - -<p>The conclusions that may be drawn from this experiment, afford a -striking instance of the importance of the application of the science -of quantity to the chemical changes: for the data being one chemical -fact, the decomposition of a given quantity of nitrous gas by known -agents; the composition of nitrous gas, of water, ammoniac, the oxides -of iron, and sulphate of ammoniac; we are able not only to determine -the quantities of the simple constituents that have entered into new -arrangements, but likewise the composition of two compound bodies, the -green and red sulphates of iron.<a id="FNanchor_121" href="#Footnote_121" class="fnanchor">[121]</a></p> - -<p><i>m.</i> Though from the experiments in <i>e</i> it appeared that no -decomposition of nitrous gas had been produced during or even after its -absorption by solution of sulphate of iron at the common temperature; -<span class="pagenum" id="Page_174">[Pg 174]</span> -yet a suspicion that it might take place slowly, and that indications -of it might be given by deposition, induced me to examine minutely -two impregnated solutions, one of which had been at rest, confined by -mercury, for 19 hours, and the other for 27. In neither of them could I -discover any deposition, or alteration of color, which might denote a change.</p> - -<p>Two cubic inches of oxygene were admitted to half a cubic inch of one -of these solutions. The oxygene was slowly absorbed, and the solution -gradually lost its color.</p> - -<p>To ascertain if during the conversion of the nitrous gas held in -solution by sulphate of iron, into nitric acid, by the oxygene of the -atmosphere at the common temperature, any water was decomposed; I -suffered an impregnated solution, weighing nearly two ounces, to remain -in contact with the atmosphere at 57°-62°, till it was become perfectly -pale. It then had a strong acid taste, effervesced with carbonate of -potash, and gave a blue precipitate with prussiate of potash.—It was -<span class="pagenum" id="Page_175">[Pg 175]</span> -saturated with quicklime, and heated: slight indications of the -presence of ammoniac were perceived.</p> - -<p>As in this experiment the nitric acid had been most probably decomposed -by the green oxide of iron, as in <i>f</i>, I sent oxygenated muriatic -acid through an impregnated solution, till all the green oxide of iron -was converted into red, and all the nitrous gas into nitric acid.</p> - -<p>This solution saturated with potash, and heated, gave no ammoniacal smell.</p> - -<p>From these experiments we may conclude,</p> - -<p>1st. That solution of red sulphate of iron has little or no affinity -for nitrous gas<a id="FNanchor_122" href="#Footnote_122" class="fnanchor">[122]</a>; -and that solution of common sulphate absorbs nitrous gas only in -proportion as it contains green sulphate.</p> - -<p>2dly. That solutions of green sulphate of iron dissolve nitrous gas in -quantities proportionable to their concentration, without effecting any -<span class="pagenum" id="Page_176">[Pg 176]</span> -decomposition of it at common temperatures. And the solubility of -nitrous gas in solution of green sulphate, may be supposed to depend -on an equilibrium of affinity, produced by the following simple -attractions:</p> - -<div class="blockquot"> -<p>1. That of green oxide of iron for the oxygene of nitrous gas and -water.</p> - -<p>2. That of the hydrogene of the water for the nitrogene of the -nitrous gas.</p> - -<p>3. That of the principles of the sulphuric acid, for nitrogene and -hydrogene.</p> -</div> - -<p>3dly. That at high temperatures, that is, from 200° to 300°, the -equilibrium of affinity producing the binary combination between -nitrous gas and solution of green sulphate of iron is destroyed; the -attraction of the green oxide of iron for oxygene being increased; -whilst probably that of nitrogene for hydrogene is diminished. -<span class="pagenum" id="Page_177">[Pg 177]</span></p> - -<p>Hence the nitrous gas is either liberated,<a id="FNanchor_123" href="#Footnote_123" class="fnanchor">[123]</a> -in consequence of the affinity between oxygene and hydrogene, and -oxygene and nitrogene not following the same ratio of alteration on -increased temperature; or decomposed, because at a certain temperature -the green oxide exerts such affinities upon water and nitrous gas, as -to attract oxygene from both of them to form red oxide; whilst the -still existing affinity between the hydrogene of the one, and the -nitrogene of the other, disposes them to combine to form ammoniac.</p> - -<p>4thly. That the change of color produced by introducing nitric acid -to solution of common sulphate of iron, exactly analogous to that -occasioned in it by impregnation with nitrous gas, is owing to the -decomposition of the acid, by the combination of its oxygene with the -<span class="pagenum" id="Page_178">[Pg 178]</span> -green oxide of iron, and of its nitrous gas with the solution.</p> - -<p>5thly. That nitrous gas in combination with solution of green sulphate -of iron, is capable of exerting a strong affinity upon free or loosely -combined oxygene, and of uniting with it to form nitric acid.</p> - -<p><i>n.</i> The products obtained from a solution of sulphate of iron -saturated with nitrous gas, by Vauquelin and Humbolt, and their -consequent mistake with regard to the nature of the process of -absorption,<a id="FNanchor_124" href="#Footnote_124" class="fnanchor">[124]</a> -must have arisen from exposure of their impregnated solution -to the atmosphere.</p> - -<p>Indeed, from the acidity of it, on examination, from the small portion -of ammoniac, and the large quantity of nitric acid obtained, it appears -most probable that the whole of the nitrous gas employed was converted -into nitric acid, by combining with atmospheric oxygene; for no nitric -<span class="pagenum" id="Page_179">[Pg 179]</span> -acid could have been obtained in the mode in which they operated, -unless the green oxide of iron in the solution had been previously -converted into red.</p> - -<p id="RI_DIV_08" class="f120 space-above1">VIII. <i>On the absorption -of Nitrous Gas by<br /> solution of green Muriate of Iron.</i></p> - -<p><i>a.</i> The analogy between the affinities of the constituents of -the muriate and sulphate of iron, induced me to conjecture that they -possessed similar powers of absorbing nitrous gas; and I soon found -that this was actually the case; for on agitating half a cubic inch -of solution of muriated iron, procured by dissolving iron filings -in muriatic acid, in nitrous gas, the gas was absorbed with great -rapidity, whilst the solution assumed a deep and bright brown tinge.</p> - -<p><i>b.</i> Proust,<a id="FNanchor_125" href="#Footnote_125" class="fnanchor">[125]</a> -who as I have before mentioned, supposes the existence of two -<span class="pagenum" id="Page_180">[Pg 180]</span> -oxides of iron only, one containing ²⁷/₁₀₀ oxygene, the other ⁴⁸/₁₀₀, -has assumed, that the muriatic acid, and most other acids as well as -the sulphuric, are capable of combining with these oxides, and of -forming with each of them a distinct salt. He has, however, detailed no -experiments on the muriates of iron.</p> - -<p>As these salts are still more distinct from each other in their -properties than the sulphates, and as these properties are connected -with the phænomenon of the absorption and decomposition of nitrous gas, -I shall detail the observations I have been able to make upon them.</p> - -<p><i>c.</i> When iron filings have been dissolved in pure muriatic acid, -and the solution preserved from the contact of air, it is of a pale -green color, and gives a white precipitate with alkaline prussiates. -The alkalies throw down from it a light green oxide of iron.</p> - -<p>When evaporated, it gives crystals almost white, which are extremely -soluble in water; but insoluble in alcohol. -<span class="pagenum" id="Page_181">[Pg 181]</span></p> - -<p>The solution of green muriate of iron has a great affinity for oxygene, -and attracts it from the atmosphere, from nitric acid, and probably -from oxygenated muriatic acid.</p> - -<p>When red oxide of iron is dissolved in muriatic acid, or when nitric -acid is decomposed by solution of green muriate of iron; the red -muriate of iron is produced. The solution of this salt is of a deep -brown red, its odor is peculiar, and its taste, even in a very diluted -state, highly astringent. It acts upon animal and vegetable matters in -a manner somewhat analogous to the oxygenated muriatic acid, rendering -them yellowish white, or yellow.<a id="FNanchor_126" href="#Footnote_126" class="fnanchor">[126]</a></p> - -<p>Sulphuric acid poured upon it, produces a smell resembling that of -oxygenated muriatic acid. Evaporated at a low temperature, it gives an -uncrystalisable dark, orange colored salt, which is soluble in alcohol, -and when decomposed by the alkalies, gives a red precipitate. With -prussiate of potash it gives prussian blue. -<span class="pagenum" id="Page_182">[Pg 182]</span></p> - -<p>The common muriate of iron consists of different proportions of these -two salts. It may be converted into red muriate by concentrated nitric -acid, or into green by sulphurated hydrogene.</p> - -<p><i>d.</i> To ascertain if solution of red muriate of iron was capable -of absorbing nitrous gas, I introduced into a jar filled with mercury, -a cubic inch of nitrous gas, and admitted to it nearly half a cubic -inch of solution of red muriate of iron. No discoloration took place. -By much agitation, however, an absorption of nearly,2 was produced, -and the solution became of a muddy green. But this change of color, and -probably the absorption, was in consequence of the oxydation of either -the mercury, or some imperfect metals combined with it, by the oxygene -of the red muriate. For I afterwards found, that precisely the same -change of color was produced when a solution was agitated over mercury.</p> - -<p><i>e.</i> I introduced to a cubic inch of concentrated solution of -<span class="pagenum" id="Page_183">[Pg 183]</span> -green muriate of iron, 7 cubic inches of nitrous gas, free from -nitric acid; the solution instantly became colored at the edges, and -on agitation absorbed the gas with much greater rapidity than even -sulphate of iron; in a minute, only a quarter of a cubic inch remained.</p> - -<p>The solution appeared of a very dark brown, but evidently no -precipitation had taken place in it, and the edges, when viewed against -the light, were transparent and puce colored.</p> - -<p>Five cubic inches more of nitrous gas were now dissolved in the -solution. The intensity of the color increased, and after an hour no -deposition had taken place. A little of it was then examined in the -atmosphere; it had a much more astringent taste than the unimpregnated -solution, and effected no change in red cabbage juice. When prussiate -of potash was introduced into it, its color changed to olive brown. A -few drops of the solution, that had accidentally fallen on the mercury, -soon became colorless, and then effervesced with carbonate of potash, -and tasted strongly acid. -<span class="pagenum" id="Page_184">[Pg 184]</span></p> - -<p>The remainder of the impregnated solution, which must have nearly -equalled,75 cubic inches, was introduced into a mattrass, having a -stopper and curved tube, as in the experiments on the solution of -sulphate of iron; great care being taken to preserve it from the -contact of air.</p> - -<p>The mattrass was heated by a spirit lamp, the curved tube being in -communication with a mercurial cylinder. Near 8 cubic inches of nitrous -gas were collected, when the solution became of a muddy yellow. It was -suffered to cool, and examined. A small quantity of yellow precipitate -covered the bottom of the mattrass; the fluid was pellucid, and -light green. A little of it thrown on prussiate of potash, gave a -white precipitate, colored by streaks of light blue. When the yellow -precipitate was partly dissolved by sulphuric acid, a drop of the -solution, mingled with prussiate of potash, gave a deep blue green.</p> - -<p>Hence, evidently, the precipitate was red oxide of iron. -<span class="pagenum" id="Page_185">[Pg 185]</span></p> - -<p>Caustic potash in excess was introduced into the remainder of the -solution, and it was heated. It gave an evident smell of ammoniac, and -dense white fumes, when held over strong phlogisticated nitrous acid.</p> - -<p>When half of it was evaporated, sulphuric acid in excess was poured on -the remainder; muriatic acid was liberated, not perceptibly combined -with any nitric acid.</p> - -<p><i>f.</i> In an experiment that I made to ascertain the quantity of -nitrous gas capable of combining with solution of green muriate of -iron; I found that,75 cubic inches of saturated solution absorbed -about 18 of nitrous gas, which is nearly double the quantity combinable -with an equal portion of the strongest solution of sulphate of iron. -A part of this impregnated solution, heated slowly, gave out more -gas in proportion to the quantity it contained, than the last, and -consequently produced less precipitate; so that I am inclined to -suppose it probable, that at a certain temperature, all the dissolved -nitrous gas may be dispelled from a solution. -<span class="pagenum" id="Page_186">[Pg 186]</span></p> - -<p>From these experiments we may conclude,</p> - -<p>1st. That the solution of green muriate of iron absorbs nitrous gas in -consequence of nearly the same affinities as solution of green sulphate -of iron; its capability of absorbing larger quantities depending -most probably on its greater concentration (that is, on the greater -solubility of the muriate of iron), and perhaps, in some measure, on a -new combining affinity, that of muriatic acid for oxygene.</p> - -<p>2dly. That at certain temperatures nitrous gas is either liberated from -solution of green muriate, or decomposed, by the combination of its -oxygene with green oxide of iron, and of its nitrogene with hydrogene, -produced from water decompounded by the oxide at the same time. -<span class="pagenum" id="Page_187">[Pg 187]</span></p> - -<p id="RI_DIV_09" class="f120 space-above1">IX. <i>Absorption of Nitrous Gas by<br /> -Solution of Nitrate of Iron.</i></p> - -<p><i>a.</i> As well as two sulphates and two muriates of iron, there -exist two nitrates.<a id="FNanchor_127" href="#Footnote_127" class="fnanchor">[127]</a> -When concentrated nitric acid is made to act upon iron, nitrous gas is -disengaged with great rapidity, and with great increase of temperature: -the solution assumes a yellowish tinge, and as the process goes on, a -yellow red oxide is precipitated.</p> - -<p>Nitrate of iron made in this way, gives a bright blue mingled with -prussiate of potash, and decomposed by the alkalies, a red precipitate. -Its solution has little or no affinity for nitrous gas.</p> - -<p><i>b.</i> When very dilute nitric acid, that is, such as of specific -gravity 1,16, is made to oxydate iron, without the assistance of heat, -the solution gives out no gas for some time, and becomes dark olive -brown: when neutralised it gives, decomposed by the alkalies, a light -green precipitate; and mingled with prussiate of potash, pale green -prussiate of iron. -<span class="pagenum" id="Page_188">[Pg 188]</span></p> - -<p>It owes its color to the nitrous gas it holds in solution. By exposure -to the atmosphere it becomes pale, the nitrous gas combined with it -being converted into nitric acid.</p> - -<p>It is then capable of absorbing nitrous gas, and consists of pale -nitrate of iron, mingled with red nitrate.</p> - -<p>I have not yet obtained a nitrate of iron giving only a white -precipitate with prussiate of potash, that is, such as contains -<i>only</i> oxide of iron at its minimum of oxydation; for when pure -green oxide of iron is dissolved by very dilute nitric acid, a small -quantity of the acid is generally decomposed, which is likewise the -case in the decomposition of nitre by green sulphate of iron. The -solutions of nitrate of iron, however, procured in both of these modes, -absorb nitrous gas with rapidity, and by sulphurated hydrogene might -probably be converted into pale nitrate.</p> - -<p>As it is impossible to obtain concentrated solutions of pale nitrate -of iron, chiefly containing green oxide, its powers of absorbing nitrous -<span class="pagenum" id="Page_189">[Pg 189]</span> -gas cannot be compared with the muriatic and sulphuric solutions, -unless they are made of nearly the same specific gravity.</p> - -<p>Nitrous gas is disengaged by heat from the impregnated solution of -nitrate of iron, at the same time that much red oxide of iron is -precipitated. Whether any nitrous gas is decomposed, I have not yet -ascertained; for when unimpregnated pale nitrate of iron is heated, -a part of the acid, and of the water of the solution, is decomposed -by the green oxide of iron;<a id="FNanchor_128" href="#Footnote_128" class="fnanchor">[128]</a> -and in consequence ammoniac, and red nitrate of iron formed, -whilst red oxide is precipitated.</p> - -<p id="RI_DIV_10" class="f120 space-above1">X. <i>Absorption of -Nitrous Gas by other<br /> Metallic Solutions.</i></p> - -<p><i>a.</i> White prussiate of iron in contact with water absorbs nitrous -gas to a great extent, and becomes dark chocolate.<a id="FNanchor_129" href="#Footnote_129" class="fnanchor">[129]</a></p> - -<p><span class="pagenum" id="Page_190">[Pg 190]</span> -<i>b.</i> Concentrated solution of sulphate of tin, <i>probably</i> at -its minimum of oxydation, absorbs one eighth of its bulk of nitrous -gas, and becomes brown, without deposition.</p> - -<p><i>c.</i> Solution of sulphate of zinc absorbs about one tenth of its -volume of nitrous gas, and becomes green.</p> - -<p><i>d.</i> Solution of muriate of zinc<a id="FNanchor_130" href="#Footnote_130" class="fnanchor">[130]</a> -absorbs nearly the same quantity, and becomes orange brown.</p> - -<p><i>e.</i> These are all the metallic substances on which I have -experimented. It is more than probable that there exist others -possessing similar powers of absorbing nitrous gas.</p> - -<p>Whenever the metals capable of decomposing water exist in solutions at -<span class="pagenum" id="Page_191">[Pg 191]</span> -their minimum of oxydation, the affinities exerted by them on nitrous -gas and water, will be such as to produce combination. The powers of -metallic solutions to combine with nitrous gas at common temperatures, -as well as to decompose it at higher temperatures, will probably be -in the ratio of the affinity of the metallic oxides they contain, for oxygene.</p> - -<p id="RI_DIV_11" class="f120 space-above1">XI. <i>The action of -Sulphurated Hydrogene on solution of<br /> Green Sulphate of Iron, -impregnated with Nitrous Gas.</i></p> - -<p><i>a.</i> In an experiment on the absorption of nitrous gas by -solution of green sulphate of iron, I introduced an unboiled solution -of common sulphate, deprived of red oxide of iron by sulphurated -hydrogene, into a jar filled with nitrous gas; the absorption took -place as usual, and nearly six of gas entered into combination, the -volume of the solution being unity. On applying heat to a part of this -impregnated solution, the whole of the nitrous gas it contained -<span class="pagenum" id="Page_192">[Pg 192]</span> -(as nearly as I could guess), was expelled undecompounded, and no yellow -precipitate produced. Prussiate of potash poured into it gave only -white prussiate of iron; and when it was heated with lime, no -ammoniacal smell was perceptible.</p> - -<p>I could refer this phænomenon to no other cause than to the existence -of a small quantity of sulphurated hydrogene in the solution. That this -was the real cause I found from the following experiment.</p> - -<p><i>b.</i> One part of a solution of green sulphate of iron, formed by -the agitation of common sulphate of iron in contact with sulphurated -hydrogene, was boiled for some minutes to expel the small quantity of -gas retained by it undecompounded. It had then no peculiar smell, and -gave a white prussiate of iron with prussiate of potash; the other -part had a faint odor of sulphurated hydrogene, and gave a dirty white -precipitate with prussiate of potash. Nearly equal quantities of each -were saturated with nitrous gas, and heated. The unboiled impregnated -<span class="pagenum" id="Page_193">[Pg 193]</span> -solution gave out all its nitrous gas undecompounded; whilst in the -boiled solution it was partly decomposed, yellow precipitate and -ammoniac being formed.</p> - -<p><i>c.</i> This singular phænomenon of the power of a minute quantity -of sulphurated hydrogene, in preventing the decomposition of nitrous -gas and water, by green oxide of iron, will most probably take place in -other impregnated solutions. It seems to depend on the strong affinity -of the hydrogene of sulphurated hydrogene for oxygene.</p> - -<p id="RI_DIV_12" class="f120 space-above1">XII. <i>Additional Observations.</i></p> - -<p><i>a.</i> For separating nitrous gas from gases absorbable to no great -extent by water; a well boiled solution of green muriate of iron -should be employed. Nitrous gas agitated in this is rapidly absorbed, -and it has no affinity for, or action on, nitrogene, hydrogene, or -hydrocarbonate.</p> - -<p><i>b.</i> Nitrous gas carefully obtained from mercury and nitric acid, -<span class="pagenum" id="Page_194">[Pg 194]</span> -when received under mercury, or boiled water, and absorbed by solution -of green muriate, or sulphate of iron, rarely leaves a residuum of -¹/₂₀₀ of its volume: preserved over common water, and absorbed, the -remainder is generally from ¹/₄₀ to ¹/₉₀, from the nitrogene disengaged -by the decomposition of the common air contained in the water.</p> - -<p><i>c.</i> The nitrous gas carefully obtained from the decomposition of -nitric acid of 1,26, by copper, I have hardly ever found to contain -more than from ¹/₃₀ to ¹/₅₀ nitrogene, when received through common -water: when boiled water is employed, the residuum is nearly the same -as that of nitrous gas obtained from mercury.</p> - -<p><i>d.</i> Consequently the gas from those two solutions may be used -in common. It is more than probable, that the small quantities of -nitrogene generally mingled with nitrous gas from copper and mercury, -arise either from the common air of the vessels in which it was -produced, or that of the water over which it was received. There is no -reason for supposing that it is generated by a complete decomposition of -<span class="pagenum" id="Page_195">[Pg 195]</span> -a portion of the acid.<a id="FNanchor_131" href="#Footnote_131" class="fnanchor">[131]</a></p> - -<p><i>e.</i> Whenever nitrous oxide is mingled with nitrous gas and -nitrogene, it must be separated by well boiled water; and after the -corrections are made for the quantity of air disengaged from the water, -the nitrous gas absorbed by the muriatic solution. -<span class="pagenum" id="Page_196">[Pg 196]</span></p> - -<h3 id="RI_DIV_V">DIVISION V.</h3> - -<p class="neg-indent"><i>EXPERIMENTS and OBSERVATIONS on the production of -NITROUS OXIDE from NITROUS GAS and NITRIC ACID, in different modes.</i></p> - -<p id="RI_DV_01" class="f120">I. <i>Preliminaries.</i></p> - -<p class="no-indent"><i>a.</i></p> -<p class="drop-cap"><span class="smcap">The</span> opinions of -Priestley<a id="FNanchor_132" href="#Footnote_132" class="fnanchor">[132]</a> -and Kirwan,<a id="FNanchor_133" href="#Footnote_133" class="fnanchor">[133]</a> -relating to the causes of the conversion of nitrous gas into nitrous oxide, -were founded on the theory of phlogiston. The first of these philosophers -obtained nitrous oxide by placing nitrous gas in contact with moistened -iron filings, or the alkaline sulphures. The last by exposing it to -sulphurated hydrogene. -<span class="pagenum" id="Page_197">[Pg 197]</span></p> - -<p>The Dutch chemists,<a id="FNanchor_134" href="#Footnote_134" class="fnanchor">[134]</a> -the latest experimentalists on nitrous oxide, have supposed that the -production of this substance depends upon the simple abstraction of -a portion of the oxygene of nitrous gas. They obtained nitrous oxide -by exposing nitrous gas to muriate of tin, to copper in solution of -ammoniac, and likewise by passing it over heated sulphur.</p> - -<p>The diminution of volume sustained by nitrous gas during its conversion -into nitrous oxide, has never been accurately ascertained; it has -generally been supposed to be from two thirds to eight tenths.</p> - -<p><i>b.</i> Nitrous gas may be converted into nitrous oxide in two modes.</p> - -<p>First, by the simple abstraction of a portion of its oxygene, by bodies -possessing a strong affinity for that principle, such as alkaline -sulphites, muriate of tin, and dry sulphures.</p> - -<p>Second, by the combination of a body with a portion both of its -oxygene and nitrogene, such as hydrogene, when either in a nascent -form, or a peculiar state of combination. -<span class="pagenum" id="Page_198">[Pg 198]</span></p> - -<p><i>c.</i> Each of these modes will be distinctly treated of; and to -prevent unnecessary repetitions, I shall give an account of the general -manner in which the following experiments on the conversion of nitrous -gas into nitrous oxide, have been conduced.</p> - -<p>Nitrous gas, the purity of which has been accurately ascertained by -solution of muriate of iron, is introduced into a graduated jar filled -with dry mercury. If a fluid substance is designed for the conversion -of the gas into nitrous oxide, it is heated, to expel any loosely -combined air which might be liberated during the process; and then -carefully introduced into the jar, by means of a small phial. After the -process is finished, and the diminution accurately noted, the nitrous -oxide formed is absorbed by pure water. If any nitrous gas remains, it -is condensed by solution of muriate of iron; other residual gases are -examined by the common tests. The quantity of nitrous oxide dissolved -by the fluid is determined by a comparative experiment; and the -<span class="pagenum" id="Page_199">[Pg 199]</span> -corrections for temperature and pressure being guessed at, the -conclusions drawn.</p> - -<p>If a solid substance is used, rather more nitrous gas than that -designed for the conversion, is introduced into the jar. The substance -is brought in contact with the gas, by being carried under the mercury; -and as a little common air generally adheres to it, a small portion -of the nitrous gas is transferred into a graduated tube, after the -insertion, and its purity ascertained. In other respects the process is -conducted as mentioned above.</p> - -<p id="RI_DV_02" class="f120 space-above1">II. <i>Of the conversion -of Nitrous gas into Nitrous Oxide,<br /> by Alkaline Sulphites.</i></p> - -<p>The alkaline sulphites, particularly the sulphite of potash, convert -nitrous gas into nitrous oxide, with much greater rapidity than any -other bodies.</p> - -<p>At temperature 46°, 16 cubic inches of nitrous gas were converted, in -<span class="pagenum" id="Page_200">[Pg 200]</span> -less than an hour, into 7,8 of nitrous oxide, by about 100 grains of -pulverised sulphite of potash, containing its water of crystalisation. -No sensible increase of temperature was produced during the process, -no water was decomposed, and the quantity of nitrogene remaining after -the experiment, was exactly equal to that previously contained in the -nitrous gas.</p> - -<p>The nitrous oxide produced from nitrous gas by sulphite of potash, has -all the properties of that generated from the decomposition of nitrate -of ammoniac. It gives, as will be seen hereafter, the same products by -analysis. Phosphorus, the taper, sulphur, and charcoal, burn in it with -vivid light. It is absorbable by water, and capable of expulsion from -it unaltered, by heat.</p> - -<p>Nitrous gas is converted into nitrous oxide by the alkaline sulphites -with the same readiness, whether exposed to the light, or deprived of -its influence.</p> - -<p>The solid sulphites act upon nitrous gas much more readily than their -<span class="pagenum" id="Page_201">[Pg 201]</span> -concentrated solutions; they should however always be suffered to -retain their water of crystalisation, or otherwise they attract -moisture from the gas, and render it drier, and in consequence more -condensed than it would otherwise be. In case perfectly dry sulphites -are employed, the gas should be always saturated with moisture after -the experiment, by introducing into the cylinder a drop of water.</p> - -<p>The sulphites, after exposure to nitrous gas, are either found wholly, -or partially, converted into sulphates. Consequently the conversion of -nitrous gas into nitrous oxide by these bodies, simply depends on the -abstraction of a portion of its oxygene; the nitrogene and remaining -oxygene assuming a more condensed state of existence.</p> - -<p>If we reason from the different specific gravities of nitrous oxide -and nitrous gas, as compared with the diminution of volume of nitrous -gas, during its conversion into nitrous oxide, 100 parts of nitrous -gas, supposing the former estimation of the composition of nitrous -<span class="pagenum" id="Page_202">[Pg 202]</span> -oxide given in <a href="#RI_DIV_III">Division III</a>, accurate, -would consist of 54 oxygene, and 46 nitrogene; which is not far from -the true estimation. Or assuming the composition of nitrous gas, as -given in <a href="#RI_DIV_IV">Division IV</a>, it would appear from the -diminution, that 100 parts of nitrous oxide consisted of 38 oxygene, -and 62 nitrogene.</p> - -<p id="RI_DV_03" class="f120 space-above1">III. <i>Conversion of Nitrous Gas -into Nitrous Oxide,<br /> by Muriate of Tin, and dry Sulphures.</i></p> - -<p><i>a.</i> Nitrous gas exposed to dry muriate of tin, is slowly -converted into nitrous oxide: during this process the apparent -diminution is to about one half; but if the products are nicely -examined, and the necessary corrections made, the real diminution of -nitrous gas by muriate of tin, will be the same as by the sulphites; -that is, 100 parts of it will be converted into 48 of nitrous oxide.</p> - -<p>During this conversion, no water is decomposed, and no nitrogene -evolved. Solution of muriate of tin converts nitrous gas into nitrous -oxide; but with much less rapidity than the solid salt. -<span class="pagenum" id="Page_203">[Pg 203]</span></p> - -<p><i>b.</i> Nitrous gas exposed to dry and perfectly well made sulphures, -particularly such as are produced from crystalised alumn<a id="FNanchor_135" href="#Footnote_135" class="fnanchor">[135]</a> -and charcoal not sufficiently inflammable to burn in the atmosphere, is -converted into nitrous oxide by the simple abstraction of a portion of -its oxygene, and consequently undergoes a diminution of ⁵²/₁₀₀.</p> - -<p>It is probable, that all the bodies having strong affinity for oxygene -will, at certain temperatures, convert nitrous gas into nitrous oxide. -Priestley, and the Dutch chemists, effected the change by heated -sulphur. Perhaps nitrous gas sent through a tube heated, but not -ignited, with phosphorus, would be converted into nitrous oxide.</p> - -<p id="RI_DV_04" class="f120 space-above1">IV. <i>Decomposition of Nitrous Gas, -by Sulphurated Hydrogene.</i></p> - -<p><span class="pagenum" id="Page_204">[Pg 204]</span> -<i>a.</i> When nitrous gas and sulphurated hydrogene are mingled -together, a decomposition of them slowly takes place. The gases are -diminished, sulphur deposited, nitrous oxide formed, and signs of the -production of ammoniac<a id="FNanchor_136" href="#Footnote_136" class="fnanchor">[136]</a> -and water perceived.</p> - -<p>In this process no sulphuric, or sulphureous acid is produced; -consequently none of the sulphur is oxydated, and of course the changes -depend upon the combination of the hydrogene of the sulphurated -hydrogene, with different portions of the oxygene and nitrogene of the -nitrous gas, to form water and ammoniac, the remaining oxygene and -nitrogene assuming the form of nitrous oxide.</p> - -<p>This singular exertion of attractions by a simple body, appears -highly improbable a priori, nor did I admit it, till the formation of -ammoniac, and the non-oxygenation of the sulphur, were made evident by -many experiments.</p> - -<p>In those experiments, the diminution of the nitrous gas was not -<span class="pagenum" id="Page_205">[Pg 205]</span> -uniformly the same. It varied from ¹¹/₂₀ to ¹⁴/₂₀. In the most accurate -of them, 5 cubic inches of nitrous gas were converted into 2.2 of -nitrous oxide. Consequently the quantity of ammoniac formed was,047 grains.</p> - -<p>In experiments on the conversion of nitrous gas into nitrous oxide, by -sulphurated hydrogene, the gases should be rendered as dry as possible. -The presence of water considerably retards the decomposition.</p> - -<p><i>b.</i> The sulphures<a id="FNanchor_137" href="#Footnote_137" class="fnanchor">[137]</a> -dissolved in water convert nitrous gas into nitrous oxide. This -decomposition is not, however, produced by the simple abstraction of -oxygene from the nitrous gas to form sulphuric acid. It depends as well -on the decomposition of the sulphurated hydrogene dissolved in the -solution, or liberated from it. In this process sulphur is deposited on -the surface of the fluid, sulphuric acid is formed, and the diminution, -making the necessary corrections, is nearly the same as when free -sulphurated hydrogene is employed. -<span class="pagenum" id="Page_206">[Pg 206]</span></p> - -<p>It is extremely probable that sulphurated hydrogene, in combination -with the alkalies, as well as with water, is capable of being slowly -decomposed by nitrous gas.</p> - -<p id="RI_DV_05" class="f120 space-above1">V. <i>Decomposition of -Nitrous Gas by Nascent Hydrogene.</i></p> - -<p><i>a.</i> When nitrous gas, is exposed to wetted iron filings, a -diminution of its volume slowly takes place; and after a certain time, -it is found converted into nitrous oxide.</p> - -<p>In this process ammoniac<a id="FNanchor_138" href="#Footnote_138" class="fnanchor">[138]</a> -is formed, and the iron partially oxydated. -<span class="pagenum" id="Page_207">[Pg 207]</span></p> - -<p>The water in contact with the iron is decomposed by the combination of -its oxygene with that substance, and of its hydrogene with a portion -of the oxygene and nitrogene of the nitrous gas, to form water and ammoniac.</p> - -<p>That the iron is not oxydated at the expence of the oxygene of the -nitrous gas, appears very probable from the analogy between this -process, and the mutual decomposition of nitrous gas and sulphurated -hydrogene. Besides, dry iron filings effect no change whatever in -nitrous gas, at common temperatures.</p> - -<p>I have generally found about 12 of nitrous gas converted into 5 of -nitrous oxide in this process; which is not very different from the -diminution by sulphurated hydrogene. It takes place equally well in -light and darkness; but more rapidly in warm weather than in cold.</p> - -<p><i>b.</i> Nitrous gas exposed to a large surface of zinc, in contact -with water, is slowly converted into nitrous oxide; at the same time -that ammoniac is generated, and white oxide of zinc formed. This -<span class="pagenum" id="Page_208">[Pg 208]</span> -process appears to depend, like the last, upon the decomposition of -water by the affinities of part of the oxygene and nitrogene of nitrous -gas, for its hydrogene, to form ammoniac and water; and by that of -zinc for its oxygene. Zinc placed in contact with water, and confined -by mercury,<a id="FNanchor_139" href="#Footnote_139" class="fnanchor">[139]</a> -decomposes it at the common temperature. Zinc, when perfectly dry, does -not in the slightest degree act upon nitrous gas.</p> - -<p>I have not been able to determine exactly the diminution of volume of -nitrous gas, during its conversion into nitrous oxide by zinc. In one -experiment 20 measures of nitrous gas, containing about,03 nitrogene, -were diminished to 9, after an exposure of eight days to wetted zinc; -but from an accident, I was not able to ascertain the exact quantity of -nitrous oxide formed.</p> - -<p><i>c.</i> It is probable that most of the imperfect metals will be -found capable of oxydation, by the decomposition of water, when its -<span class="pagenum" id="Page_209">[Pg 209]</span> -hydrogene is attracted by the oxygene and nitrogene of nitrous gas. -I have this day (April 14, 1800), examined two portions of nitrous -gas, one of which had been exposed to copper filings, and the other to -powder of tin, for twenty-three days.</p> - -<p>The gas that had been exposed to copper was diminished nearly two -fifths. The taper burnt in it with an enlarged flame, blue at the -edges. Hence it evidently contained nitrous oxide.</p> - -<p>The nitrous gas in contact with tin had undergone a diminution of one -fourth only, and did not support flame.</p> - -<p id="RI_DV_06" class="f120 space-above1">VI. <i>Miscellaneous Observations -on the conversion<br /> of Nitrous Gas into Nitrous Oxide.</i></p> - -<p><i>a.</i> Dr. Priestley found nitrous gas exposed to a mixture of iron -filings and sulphur, with water, converted after a certain time, into -nitrous oxide. Sulphurated hydrogene is always produced during the -combination of iron and sulphur, when they are in contact with water; -<span class="pagenum" id="Page_210">[Pg 210]</span> -and by the hydrogene of this in the nascent state, the nitrous gas is -most probably decomposed.</p> - -<p><i>b.</i> Green oxide of iron moistened with water, exposed to nitrous -gas, slowly gains an orange tinge, whilst the gas is diminished. -Most likely it is converted into nitrous oxide; but this I have not -ascertained.</p> - -<p><i>c.</i> I exposed nitrous gas, to the following bodies over mercury -for many days, without any diminution, or apparent change in its -properties. Alcohol, saccharine matter, hydrocarbonate, sulphureous -acid, and phosphorus.</p> - -<p><i>d.</i> Crystalised sulphate, and muriate of iron, absorb a small -quantity of nitrous gas, and become dark colored on the outside; but -after this absorption, (which probably depends on their water of -crystalisation,) has taken place, no change is effected in the gas -remaining.</p> - -<p><i>e.</i> The power of iron to decompose water being much increased by -increase of temperature, nitrous gas is converted into nitrous oxide -much more rapidly when placed in contact with a surface of heated iron, -<span class="pagenum" id="Page_211">[Pg 211]</span> -than when exposed to it at common temperatures. During the -decomposition of nitrous gas in this way, ammoniac<a id="FNanchor_140" href="#Footnote_140" class="fnanchor">[140]</a> -is formed.</p> - -<p><i>f.</i> The curious experiments of Rouppe,<a id="FNanchor_141" href="#Footnote_141" class="fnanchor">[141]</a> -on the absorption of gases by charcoal, compared with the phænomena -noticed in this Division, render it probable that hydrogene in a state -of loose combination with charcoal, will be found to convert nitrous -gas into nitrous oxide.</p> - -<p id="RI_DV_07" class="f120 space-above1">VII. <i>Recapitulation of conclusions -concerning the<br /> conversion of Nitrous Gas into Nitrous Oxide.</i></p> - -<p><i>a.</i> Certain bodies having a strong affinity for oxygene, as the -sulphites, dry sulphures, muriate of tin, &c. convert nitrous gas into -nitrous oxide, by simply attracting a portion of its oxygene; whilst -<span class="pagenum" id="Page_212">[Pg 212]</span> -the remaining oxygene enters into combination with the nitrogene, and -they assume a more condensed state of existence.</p> - -<p><i>b.</i> Nitrous gas is converted into nitrous oxide by hydrogene, in -a peculiar state of existence, as in sulphurated hydrogene; and that -by a series of very complex affinities. Both oxygene and nitrogene are -attracted from the nitrous gas by the hydrogene, in such proportions -as to form water and ammoniac, whilst the remaining oxygene and -nitrogene<a id="FNanchor_142" href="#Footnote_142" class="fnanchor">[142]</a> -assume the form of nitrous oxide.</p> - -<p><i>c.</i> Nitrous gas placed in contact with bodies, such as iron and -zinc decomposing water, is converted into nitrous oxide, at the same -time that ammoniac is formed. It is difficult to ascertain the exact -rationale of this process. For either the nascent hydrogene produced by -the decomposition of the water by the metallic substance may combine -<span class="pagenum" id="Page_213">[Pg 213]</span> -with portions of both the oxygene and nitrogene of the nitrous gas; and -thus by forming water and ammoniac, convert it into nitrous oxide. Or -the metallic substance may attract at the same time oxygene from the -water and nitrous gas, whilst the nascent hydrogene of the water seizes -upon a portion of the nitrogene of the nitrous gas to form ammoniac.</p> - -<p>The degree of diminution, and the analogy between this process and the -decomposition of nitrous gas by sulphurated hydrogene, render the first -opinion most probable.</p> - -<p id="RI_DV_08" class="f120 space-above1">VIII. <i>The production -of Nitrous Oxide during the<br /> oxydation of Tin, Zinc, and Iron, -in Nitric Acid.</i></p> - -<p><i>a.</i> Dr. Priestley discovered, that during the solution of -tin, zinc, and iron, in nitric acid, certain portions of nitrous -oxide were produced, mingled with quantities of nitrous gas, and -nitrogene, varying in proportion as the acid employed was more or -less concentrated. -<span class="pagenum" id="Page_214">[Pg 214]</span></p> - -<p>It has long been known that ammoniac is formed during the solution of -tin, zinc, and iron, in diluted nitric acid. Consequently, in these -processes water is decomposed.</p> - -<p>I had designed to investigate minutely these phænomena, so as to -ascertain the quantities of water and acid decompounded, and of the new -products generated. But after going through some experiments on the -oxydation of tin without gaining conclusive results, the labor, and -sacrifice of time they demanded, obliged me to desist from pursuing the -subject, till I had completed more important investigations.</p> - -<p>I shall detail the few observations which have occurred to me, relating -to the production of nitrous oxide from metallic solutions.</p> - -<p><i>b.</i> When tin is dissolved in concentrated nitric acid, such -as of 1.4, nitrous oxide is produced, mingled with generally more -than twice its bulk of nitrous gas. In this process but little free -nitrogene is evolved, and the tin is chiefly precipitated in the form -of a white powder. If the solution, after the generation of these -<span class="pagenum" id="Page_215">[Pg 215]</span> -products, is saturated with lime, and heated, the ammoniacal smell is -distinct.</p> - -<p>When nitric acid of specific gravity 1.24, is made to act upon tin; -in the beginning of the process, nearly equal parts of nitrous gas -and nitrous oxide are produced; as it advances, the proportion of -nitrous oxide to the nitrous gas increases: the largest quantity of -nitrous oxide that I have found in the gas procured from tin is ¾, the -remainder being nitrous gas and nitrogene.</p> - -<p>When tin is oxydated in an acid of less specific gravity than 1.09, the -quantities of gas disengaged are very small, and consist of nitrogene, -mingled with minute portions of nitrous oxide, and nitrous gas.</p> - -<p>Whenever I have saturated solutions of tin in nitric acid of different -specific gravities, with lime, and afterwards heated them, the -ammoniacal smell has been uniformly perceptible, and generally most -distinct when diluted acids have been employed. -<span class="pagenum" id="Page_216">[Pg 216]</span></p> - -<p><i>c.</i> When zinc is dissolved in nitric acid, whatever is its -specific gravity, certain quantities of nitrous oxide are produced.</p> - -<p>Nitric acids of greater specific gravity than 1.2, act upon zinc with -great rapidity, and great increase of temperature. The gases disengaged -from these solutions consist of nitrous gas, nitrous oxide, and -nitrogene; the nitrous oxide rarely equals one third of the whole.</p> - -<p>When nitric acid of 1,104 is made to dissolve zinc, the gas obtained in -the middle of the process consists chiefly of nitrous oxide. From such -a solution I obtained gas which gave a residuum of one sixth only when -absorbed by water. The taper burnt in it with a brilliant flame, and -sulphur with a vivid rose-colored light.</p> - -<p>100 grains of granulated zinc, during their solution in 300 grains -of nitric acid, of 1,43, diluted with 14 times its weight of water, -produced 26 cubic inches of gas. Of this gas ⁷/₃₆ were nitrous, ¹⁷/₃₆36 -nitrous oxide, and the remainder nitrogene. The solution saturated with -lime and heated, gave a distinct smell of ammoniac. -<span class="pagenum" id="Page_217">[Pg 217]</span></p> - -<p><i>d.</i> During the solution of iron in concentrated nitric acid, -the gas given out is chiefly nitrous; it is however generally mingled -with minute quantities of nitrous oxide. When very dilute nitric acids -are made to act upon iron, by the assistance of heat, nitrous oxide -is produced in considerable quantities, mingled with nitrous gas -and nitrogene; the proportions of which are smaller as the process -advances.<a id="FNanchor_143" href="#Footnote_143" class="fnanchor">[143]</a> -The fluid remaining after the oxydation and solution of iron in -nitric acid, always contains ammoniac.</p> - -<p><i>e.</i> As during the solution of tin, zinc, and iron, in nitric -acid, the quantity of acid is diminished in proportion as the process -advances, it is reasonable to suppose that the relative quantities -of the gases evolved are perpetually varying. In the beginning of a -<span class="pagenum" id="Page_218">[Pg 218]</span> -dissolution, the nitrous gas generally predominates, in the middle -nitrous oxide, and at the end nitrogene.</p> - -<p><i>f.</i> During the generation of nitrous gas, nitrous oxide, and -ammoniac, from the decomposition of solution of nitric acid in water, -by tin, zinc, and iron, very complex attractions must exist between -the constituents of the substances employed. The acid and the water -are decomposed at the same time, and in proportions different as the -solution is more concentrated, by the combination of their oxygene with -the metallic body.</p> - -<p>The nitrous gas is produced by the combination of the metal with -³²/₁₀₀ of the oxygene of the acid. The nitrous oxide is most probably -generated by the decomposition of a portion of the nitrous gas -disengaged, by the nascent hydrogene of the water decompounded; some -of it may be possibly formed from a more complete decomposition of the acid.</p> - -<p>The production of ammoniac may arise, probably from two causes; from -<span class="pagenum" id="Page_219">[Pg 219]</span> -the decomposition of the nitrous gas by the combination of the nascent -hydrogene of the water, with portions of its oxygene and nitrogene at -the same time; and from the union of hydrogene with nascent nitrogene -liberated in consequence of a complete decomposition of part of the -acid.</p> - -<p id="RI_DV_09" class="f120 space-above1">IX. <i>Additional Observations -on the production<br /> of Nitrous Oxide.</i></p> - -<p><i>a.</i> When nitric acid is combined with muriatic acid, or -sulphuric acid,<a id="FNanchor_144" href="#Footnote_144" class="fnanchor">[144]</a> -the quantities of nitrous oxide produced from its decomposition by tin, -zinc, and iron, are rather increased than diminished. The nitrous oxide -obtained from these solutions is, however, never sufficiently pure for -physiological experiments. It is always mingled with either nitrous -gas, nitrogene, or hydrogene, and sometimes with all of them. -<span class="pagenum" id="Page_220">[Pg 220]</span></p> - -<p><i>b.</i> From the solutions of bismuth, nickel, lead, and copper, in -diluted nitric acid, I have never obtained any perceptible quantity -of nitrous oxide: the gas produced is nitrous, mingled with different -portions of nitrogene. Antimony and mercury, during their solution in -aqua regia, give out only nitrous gas.</p> - -<p>Probably none of the metallic bodies, except those that decompose -water at temperatures below ignition, will generate nitrous oxide from -nitric acid. On cobalt and manganese I have never had an opportunity of -experimenting: manganese will probably produce nitrous oxide.</p> - -<p><i>c.</i> During the solution of vegetable matters<a id="FNanchor_145" href="#Footnote_145" class="fnanchor">[145]</a> -in nitric acid, by heat, very minute portions of nitrous oxide are -sometimes produced, always however mingled with large quantities of -nitrous gas, and carbonic acid.</p> - -<p>When nitric acid is decompounded by ether, fixed oils, volatile oils, -or alcohol, towards the end of the process small quantities of nitrous -<span class="pagenum" id="Page_221">[Pg 221]</span> -oxide are produced, and sometimes sufficiently pure to support the -flame of the taper.<a id="FNanchor_146" href="#Footnote_146" class="fnanchor">[146]</a></p> - -<p><i>d.</i> When green oxide of iron is dissolved in nitric acid, nitrous -oxide is produced, mingled with nitrogene and nitrous gas.</p> - -<p><i>e.</i> During the conversion of green sulphate, or green muriate -of iron into red, by the decomposition of dilute nitric acid, nitrous -oxide is formed, mingled with different proportions of nitrous gas and -nitrogene.</p> - -<p><i>f.</i> When solution of green nitrate of iron is heated, a part of -the acid is decomposed, red oxide is precipitated, red nitrate formed, -and impure nitrous oxide evolved.</p> - -<p><i>g.</i> When iron is introduced into a solution of nitrate of copper, -the copper is precipitated in its metallic state, whilst nitrous oxide, -mingled with small portions of nitrogene, is produced.<a id="FNanchor_147" href="#Footnote_147" class="fnanchor">[147]</a></p> - -<p>Both zinc and tin precipitate copper in its metallic form from solution -<span class="pagenum" id="Page_222">[Pg 222]</span> -in the nitric acid. During these precipitations, certain quantities of -nitrous oxide are generated, mingled however with larger quantities of -nitrogene than that produced from decomposition by iron. In all these -processes ammoniac is formed, and water consequently decomposed.</p> - -<p>The decomposition of water and nitric acid, during the precipitation -of copper from solution of nitrate of copper, by tin, zinc, and iron, -depends upon the strong affinity of those metals for oxygene, and their -powers of combining with a larger quantity of it than copper.</p> - -<p id="RI_DV_10" class="f120 space-above1">X. <i>Decomposition of -Aqua Regia by Platina, and<br /> evolution of a Gas analogous to -Oxygenated<br /> Muriatic Acid, and Nitrogene.</i></p> - -<p><i>a.</i> De la Metherie, in his essay on different airs, has asserted -that the gas produced by the solution of platina in nitro-muriatic -acid, is identical with the dephlogisticated nitrous gas of Priestly. -<span class="pagenum" id="Page_223">[Pg 223]</span> -He calls it nitrous gas with excess of pure air, and affirms that it -diminishes, both with nitrous gas and common air.</p> - -<p><i>b.</i> I introduced into a vessel containing 30 grains of platina, -2050 grains of aqua regia, composed of equal parts, by weight, of -concentrated nitric acid of 1,43, and muriatic acid of 1,16. At the -common temperature, that is, 49°, no action between the acid and -platina appeared to take place. On the application of the heat of a -spirit lamp, the solution gradually became yellow red, and gas was -given out with rapidity. Some of this gas received in a jar filled -with warm water, appeared of a bright yellow color. On agitation, -the greater part of it was absorbed by the water, and the remainder -extinguished flame. When it was received over mercury, it acted upon it -with great rapidity, and formed on the surface a white crust.</p> - -<p>As the process of solution advanced, the color of the acid changed -to dark red, at the same time that the production of gas was much -increased; more than 40 cubic inches were soon collected in the water apparatus. -<span class="pagenum" id="Page_224">[Pg 224]</span></p> - -<p>Different portions of the gas were examined, it exhibited the following -properties:</p> - -<div class="blockquot"> -<p>1. Its color was orange red,<a id="FNanchor_148" href="#Footnote_148" class="fnanchor">[148]</a> -and its smell exactly resembled that of oxygenated muriatic acid.</p> - -<p>2. When agitated in boiled water, it was rapidly absorbed, leaving a -residuum of rather more than one twelfth.</p> - -<p>3. The taper burnt in it with increased brilliancy, the flame being -long, and deep red at the edges.</p> - -<p>4. Iron introduced into it ignited, burnt with a dull red light.</p> - -<p>5. Green vegetables exposed to it were instantly rendered white.</p> - -<p>6. It underwent no diminution, mingled with atmospheric air.</p> - -<p>7. When mingled with nitrous gas, it gave dense red vapor, and rapid -diminution.</p> -</div> - -<p><span class="pagenum" id="Page_225">[Pg 225]</span> -<i>c.</i> From the exhibition of these properties, it was evident that -the gas produced during the solution of platina in aqua regia, chiefly -consisted of oxygenated muriatic acid, or of a gas highly analogous to -it. It was, however, difficult to conceive how a body, by combining -with a portion of the oxygene of nitro-muriatic acid, could produce -from it oxygenated muriatic acid, apparently mingled with very small -portions of any other gas.</p> - -<p><i>d.</i> To ascertain whether any permanent gas was produced during -the ebullition of aqua regia, of the same composition as that used for -the solution of the platina; I kept a large quantity of it boiling for -some time, in communication with the water apparatus; the gas generated -appeared to be wholly nitro-muriatic, and was absorbed as fast as -produced, by the water.</p> - -<p><i>e.</i> To determine whether any nitrous oxide was mingled with the -peculiar gas, as well as the nature and quantity of the unabsorbable -gas, nitrous gas was gradually added to 21 cubic inches of the gas -<span class="pagenum" id="Page_226">[Pg 226]</span> -produced from a new solution, till the diminution was complete: the gas -remaining equalled 2,3 cubic inches; it was unabsorbable by water, and -extinguished flame.</p> - -<p>In another experiment, when the last portions of gas from a solution -were carefully received in water previously boiled, 12 cubic inches -agitated in water left a residuum of 1.3; whilst the same quantity -decomposed by nitrous gas, containing,02 nitrogene, left about 1.5.</p> - -<p>Hence it appeared that the aëriform products of the solution consisted -of the peculiar gas analogous to oxygenated muriatic acid, and of a -small quantity of nitrogene.</p> - -<p><i>f.</i> Consequently a portion of the nitric acid of the aqua regia -had been decomposed; but if it had given oxygene both to the platina -and muriatic acid, the quantity of nitrogene evolved ought to have been -much more considerable.</p> - -<p><i>g.</i> To ascertain if any water had been decomposed, and the -nitrogene condensed in the solution by its hydrogene, to form ammoniac, -I saturated a solution with lime, and heated it, but no ammoniacal -smell was perceived. -<span class="pagenum" id="Page_227">[Pg 227]</span></p> - -<p><i>h.</i> To determine if any nitrogene had entered into chemical -combination with muriatic acid and oxygene, so as to form an aëriform -triple compound, analogous in its properties to oxygenated muriatic -acid, I exposed some of the gas to mercury, expecting that this -substance, by combining with its oxygene, would effect a complete -decomposition; and this was actually the case: for the gas was at -first rapidly diminished, and the mercury became oxydated; its volume, -however, soon increased; and the residual gas appeared to be nitrous, -mingled with much nitrogene. The exact proportions of each, from an -accident, I could not determine.</p> - -<p>This experiment was inconclusive, because the nitro-muriatic acid -suspended in the peculiar gas, from which it can probably be never -perfectly freed, acted in common with it upon the mercury, and produced -nitrous gas: and this nitrous gas, at the moment of its production, -formed nitrous acid by combining with the oxygene of the peculiar gas; -<span class="pagenum" id="Page_228">[Pg 228]</span> -and the nitrous acid generated<a id="FNanchor_149" href="#Footnote_149" class="fnanchor">[149]</a> -was again decomposed by the mercury; and hence nitrous gas evolved, -and possibly some nitrogene.</p> - -<p><i>i.</i> Peculiar circumstances prevented me at this time from -completely investigating the subject. It remains doubtful whether -the gas consists simply of highly oxygenated muriatic acid and -nitrogene,<a id="FNanchor_150" href="#Footnote_150" class="fnanchor">[150]</a> -produced by the decomposition of nitric acid from the -coalescing affinities of platina and muriatic acid for oxygene; -or whether it is composed of a <i>peculiar</i> gas, analogous to -oxygenated muriatic acid, and nitrogene, generated from some unknown -affinities.<a id="FNanchor_151" href="#Footnote_151" class="fnanchor">[151]</a></p> - -<p><span class="pagenum" id="Page_229">[Pg 229]</span></p> - -<p id="RI_DV_11" class="f120 space-above1">XI. <i>On the action of -the Electric Spark on a mixture<br /> of Nitrogene and Nitrous Gas.</i></p> - -<p><span class="pagenum" id="Page_230">[Pg 230]</span> -Thinking it possible that nitrous gas and nitrogene might be made to -combine by the action of the electric spark, so as to form nitrous -oxide, I introduced 20 grain measures of each of them into a small -detonating tube, graduated to grains, standing over mercury, and -containing a very small quantity of cabbage juice rendered green by an -alkali. After electric sparks had been passed through the gases for an -hour and half, they were diminished to about 32, and the cabbage juice -was slightly reddened. On introducing about 10 measures of hydrogene, -and passing the electric spark through the whole, no inflammation or -diminution was perceptible. Hence the condensation most probably arose -wholly from the formation of nitrous acid,<a id="FNanchor_152" href="#Footnote_152" class="fnanchor">[152]</a> -by the more intimate union of the oxygene of nitrous gas with some of -its nitrogene, as in the experiments of Priestley. -<span class="pagenum" id="Page_231">[Pg 231]</span></p> - -<p>As the nascent nitrogene, in the decomposition of nitrate of ammoniac, -combines with a portion of oxygene and nitrogene, to form nitrous -oxide; it is probable that nitrous oxide may be produced during the -passage of nitrous gas and ammoniac through a heated tube.</p> - -<p id="RI_DV_12" class="f120 space-above1">XII. <i>General Remarks.</i></p> - -<p>There are no reasons for supposing that nitrous oxide is formed in -any of the processes of nature; and the nice equilibrium of affinity by -which it is constituted, forbids us to hope for the power of composing -it from its simple principles. We must be content to produce it, either -directly or indirectly, from the decomposition of nitric acid. And as -in the decomposition of nitrate of ammoniac, not only all the nitrogene -of the nitric acid enters into the composition of the nitrous oxide -produced, but likewise that of the ammoniac, this process is by far the -cheapest, as well as the most expeditious. A mode of producing ammoniac -<span class="pagenum" id="Page_232">[Pg 232]</span> -at little expence, has been proposed by Mr. Watt. Condensed in the -sulphuric acid, it can be easily made to combine with nitric acid, -from the decomposition of nitre by double affinity. And thus, if the -hopes which the experiments at the end of those researches induce us to -indulge, do not prove fallacious, a substance which has been heretofore -almost exclusively appropriated to the destruction of mankind, may -become, in the hands of philosophy, a means of producing health and -pleasurable sensation.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_233">[Pg 233]</span></p> -<h2 id="RES_II" class="nobreak">RESEARCH II.</h2> -<p><span class="pagenum" id="Page_234">[Pg 234]</span></p> -</div> - -<p class="f120">INTO THE COMBINATIONS OF NITROUS OXIDE,<br /> AND ITS -DECOMPOSITION BY<br /> COMBUSTIBLE BODIES.</p> - -<p><span class="pagenum" id="Page_235">[Pg 235]</span></p> - -<h3 id="RII_DIV_I">DIVISION I.</h3> - -<p class="neg-indent"><i>EXPERIMENTS and OBSERVATIONS on the -COMBINATIONS of NITROUS OXIDE.</i></p> - -<p id="RII_DI_01" class="f120">I. <i>Combination of Water with Nitrous Oxide.</i></p> - -<p><i>a.</i> The discoverer of nitrous oxide first observed its solubility -in water; and it has since been noticed by different experimentalists.</p> - -<p>Dr. Priestley found that water dissolved about one half of its bulk -of nitrous oxide, and that at the temperature of ebullition, this -substance was incapable of remaining in combination with it.<a id="FNanchor_153" href="#Footnote_153" class="fnanchor">[153]</a></p> - -<p><span class="pagenum" id="Page_236">[Pg 236]</span> -<i>b.</i> I introduced to 9 cubic inches of pure water, i. e. water -distilled under mercury, 7 cubic inches of nitrous oxide, which -had been obtained over mercury, from the decomposition of nitrate -of ammoniac, and in consequence was perfectly pure. After they had -remained together for 11 hours, temperature being 46°, during which -time they were frequently agitated, the gas remaining was 2,3; -consequently 4,7 cubic inches had been absorbed. And then, 100 cubic -inches, = 25300 grains of water, will absorb 54 cubic inches, = 27 -grains, of nitrous oxide.</p> - -<p><i>c.</i> The taste of water impregnated with nitrous oxide, is -distinctly sweetish; it is softer than common water, and, in my -opinion, much more agreeable to the palate. It produces no alteration -in vegetable blues, and effects no change of color in metallic solutions.</p> - -<p><i>d.</i> Thinking that water impregnated with nitrous oxide might -probably produce some effects when taken into the stomach, by giving -<span class="pagenum" id="Page_237">[Pg 237]</span> -out its gas, I drank, in June, 1799, about 3 ounces of it, but without -perceiving any effects.</p> - -<p>A few days ago, considering this quantity as inadequate, I took at two -draughts nearly a pint, fully saturated; and at this time Mr. Joseph -Priestley drank the same quantity.</p> - -<p>We neither of us perceived any remarkable effects.</p> - -<p>Since that time I have drank near three pints of it in the course of a -day. In this instance it appeared to act as a diuretic, and I imagined -that it expedited digestion. As a matter of taste, I should always -prefer it to common water.</p> - -<p><i>e.</i> Two cubic inches of pure water, that had been made to absorb -about 1,1 cubic inches of nitrous oxide; when kept for some time in -ebullition, and then rapidly cooled, produced nearly 1 of gas. Sulphur -burnt in this gas with a vivid rose-colored flame.</p> - -<p>In another experiment, in which the gas was expelled by heat from -impregnated water, and absorbed again after much agitation on cooling; -<span class="pagenum" id="Page_238">[Pg 238]</span> -the residuum was hardly perceptible, and most likely depended upon some -gas which had adhered to the mercury, and was liberated during the -ebullition. Hence it appears that nitrous oxide is expelled unaltered -from its aqueous solution by heat.</p> - -<p><i>f.</i> I have before mentioned, <a href="#RI_DIV_III">Division III</a>, -that nitrous oxide, during its combination with spring water, expels the common -air dissolved in it. This common air generally amounts to one sixteenth, -the volume of the water being unity. A correction on account of this -circumstance must be made for the apparent deficiency of diminution, -and for the common air mingled in consequence, with nitrous oxide -during its absorption by common water.</p> - -<p><i>g.</i> Water impregnated with nitrous gas absorbed nitrous oxide; -but the residual gas was much greater than that of common water, and -gave red fumes with atmospheric air. Nitrous gas agitated for a long -while over water highly impregnated with nitrous oxide, was not in the -slightest degree diminished, in one experiment indeed it was rather -<span class="pagenum" id="Page_239">[Pg 239]</span> -increased; doubtless from the liberation of some nitrous oxide from the -water by the agitation.</p> - -<p><i>h.</i> Nitrous oxide kept in contact with aqueous solution of -sulphurated hydrogene and often agitated, was not in the slightest -degree diminished.</p> - -<p>Sulphurated hydrogene, introduced into a solution of nitrous oxide, was -rapidly absorbed, and as the process advanced, the nitrous oxide was -given out.</p> - -<p><i>i.</i> Water impregnated with carbonic acid, possessed no action -upon nitrous oxide, and did not in the slightest degree absorb it. When -carbonic acid was introduced to an aqueous solution of nitrous oxide; -the aëriform acid was absorbed, and the nitrous oxide liberated.</p> - -<p><i>k.</i> From these observations it appears that nitrous oxide has -less affinity for water, than even the weaker acids, sulphurated -hydrogene and carbonic acid; as indeed one might have conjectured a -priori from its degree of solubility: likewise that it has a stronger -attraction for water than the gases not possessed of acid or alkaline -<span class="pagenum" id="Page_240">[Pg 240]</span> -properties; it expelling from water nitrous gas, oxygene, and common -air; probably hydrocarbonate, hydrogene, and nitrogene.</p> - -<p id="RII_DI_02" class="f120 space-above1">II. <i>Combinations of -Nitrous Oxide with<br /> Fluid Inflammable Bodies.</i></p> - -<p><i>a.</i> Vitriolic ether absorbs nitrous oxide in much larger -quantities than water.</p> - -<p>A cubic inch of ether, at temperature 52°, combined with a cubic inch -and seven tenths of nitrous oxide.</p> - -<p>Ether thus impregnated was not at all altered in its appearance; its -smell was precisely the same, but the taste appeared less pungent, and -more agreeable. Nitrous oxide is liberated unaltered from ether at a -very low temperature, that is, at about the boiling point of this fluid.</p> - -<p>For expelling nitrous oxide from impregnated ether, and for -ascertaining in general the quantity of gases combined with fluids, I -have lately made use of a very simple method, which it may not be amiss -to describe. -<span class="pagenum" id="Page_241">[Pg 241]</span></p> - -<p>The impregnated fluid is introduced into a small thin tube, graduated -to,05 cubic inches, through mercury. The quantity of fluid should -never equal more than a fifth or sixth of the capacity of the tube.</p> - -<p>The lower part of the tube is adapted to an orifice in the shelf of -the mercurial apparatus, so as to make an angle of about 40° with the -surface of the mercury.</p> - -<p>The flame of a small spirit lamp is then applied to that part of the -tube containing the fluid; and after the expulsion of the gas from it, -the heat is raised so as to drive out the fluid through the orifice of -the tube. Thus the liberated gas is preserved in a state proper for -accurate examination.</p> - -<p>Impregnated ether, during its combination with water, gives out the -greater part of its nitrous oxide. During the liberation of nitrous -oxide from ether, by its combination with water, a very curious -phænomenon takes place.</p> - -<p>If the water employed is colored, so that it may be seen in a stratum -<span class="pagenum" id="Page_242">[Pg 242]</span> -distinct from the impregnated ether, at the point of contact a number -of small spherules of fluid will be perceived, apparently repulsive -both to water and ether; these spherules become gradually covered -with minute globules of gas, and as this gas is liberated from their -surfaces, they gradually disappear.</p> - -<p><i>b.</i> Alcohol dissolves considerable quantities of nitrous oxide.</p> - -<p>2 cubic inches of alcohol, at 52°, combined with 2,4 cubic inches of -nitrous oxide. The alcohol thus impregnated had a taste rather sweeter -than before, but in other physical properties was not perceptibly altered.</p> - -<p>Nitrous oxide is incapable of remaining in combination with this fluid -at the temperature of ebullition; it is liberated from it unaltered by heat.</p> - -<p>Impregnated alcohol, during its combination with water, gives out the -greater part of its combined nitrous oxide: on mingling the two fluids -together, at the point of contact the alcohol becomes covered with an -infinite number of small globules of gas, which continue to be generated -<span class="pagenum" id="Page_243">[Pg 243]</span> -during the whole of the combination, and in passing through the fluid -render it almost opaque.</p> - -<p><i>c.</i> The essential oils absorb nitrous oxide to a greater extent -than either alcohol or ether.</p> - -<p>,5 cubic inches of oil of carui combined with 1,2 cubic inches of -nitrous oxide at 51°. The color of the oil thus impregnated was rather -paler than before.</p> - -<p>Nitrous oxide is expelled unaltered from impregnated oil of carui, -by heat.</p> - -<p>1 of oil of turpentine absorbed nearly 2 of nitrous oxide, at 57°. Its -properties were not sensibly altered from this combination, and the gas -was expelled from it undecompounded, by heat.</p> - -<p><i>d.</i> As well as the essential oils, the fixed oils dissolve -nitrous oxide at low temperatures, whilst at high temperatures they do -not remain in combination.</p> - -<p>1 of olive oil absorbed, at 61°, 1,2 of nitrous oxide, but without -undergoing any apparent physical change. -<span class="pagenum" id="Page_244">[Pg 244]</span></p> - -<p id="RII_DI_03" class="f120 space-above1">III. <i>Action of -Fluid Acids on Nitrous Oxide.</i></p> - -<p><i>a.</i> Nitrous oxide exposed to concentrated sulphuric acid, -undergoes no change, and suffers no diminution, that may not be -accounted for from the abstraction of a portion of its water by the -acid.</p> - -<p><i>b.</i> Nitrous oxide is scarcely at all soluble in nitrous acid, -and exposed to that substance, undergoes no alteration.</p> - -<p><i>c.</i> Muriatic acid, of specific gravity 1,14 absorbs about a third -of its bulk of nitrous oxide. It suffers no apparent change in its -properties from being thus impregnated, and the gas is again given out -from it on the application of heat.</p> - -<p><i>d.</i> Acetic acid absorbs nearly one third of its bulk of nitrous oxide.</p> - -<p><i>e.</i> Aqua regia, that is, the nitro-muriatic acid, absorbs a very -minute portion of nitrous oxide.</p> - -<p><i>f.</i> Nitrous oxide was exposed to a new compound acid, consisting -of oxygenated muriatic acid, and sulphuric acid, which I discovered in -<span class="pagenum" id="Page_245">[Pg 245]</span> -July, 1799, and of which an account will be shortly published; but it -was neither absorbed or altered.</p> - -<p>I have before mentioned that the aqueous solutions of sulphurated -hydrogene and carbonic acid, neither dissolve or alter nitrous oxide.</p> - -<p id="RII_DI_04" class="f120 space-above1">IV. <i>Action of Saline Solutions, -and other Substances,<br /> on Nitrous Oxide.</i></p> - -<p><i>a.</i> Nitrous oxide exposed to concentrated solution of green -sulphate of iron, at 58°, underwent no perceptible diminution; not even -after it had been suffered to remain in contact with it for half an hour.</p> - -<p><i>b.</i> It underwent diminution of nearly,2 when agitated in contact -with a solution of red sulphate of iron, the volume of the solution -being unity.</p> - -<p><i>c.</i> Solution of green sulphate of iron, fully impregnated with -nitrous gas, did not in the slightest degree absorb nitrous oxide, and -appeared to have no action upon it. -<span class="pagenum" id="Page_246">[Pg 246]</span></p> - -<p><i>d.</i> Solution of green muriate of iron, whether impregnated with -nitrous gas, or unimpregnated, has no affinity for, or action upon, -nitrous oxide.</p> - -<p><i>e.</i> Solution of red muriate of iron in alcohol, absorbed nearly -one fifth of its bulk, of nitrous oxide.</p> - -<p><i>f.</i> Solution of prussiate of potash absorbed nearly one third of -its volume, of nitrous oxide, which was again expelled from it by heat.</p> - -<p><i>g.</i> Solution of nitrate of copper appeared to have no affinity -for nitrous oxide.</p> - -<p><i>h.</i> Concentrated solution of nitrate of ammoniac, at 58°, -absorbed one eighth of its bulk of nitrous oxide.</p> - -<p><i>i.</i> Solutions of alkaline sulphures absorb nitrous oxide in -quantities proportionable to the water they contain; it is expelled -from them unaltered by heat. None of the hydro-sulphures dissolve more -than half their bulk of nitrous oxide.</p> - -<p><i>k.</i> Concentrated solutions of the sulphites possess little or no -<span class="pagenum" id="Page_247">[Pg 247]</span> -action on nitrous oxide; diluted solutions absorb it in small quantities.</p> - -<p><i>l.</i> Concentrated solution of muriate of tin absorbs about one -eighth of nitrous oxide; more dilute solutions absorb larger quantities.</p> - -<p>From these observations we learn, that neutro-saline solutions in -general, have very feeble attractions for nitrous oxide; and as -solutions of green muriate, and sulphate of iron, whether free from -nitrous gas, or impregnated with it, possess no action upon nitrous -oxide, nitrous gas may be separated from this substance by those -solutions with greater facility than nitrous oxide can be separated -from nitrous gas, by water or alcohol.</p> - -<p>Charcoal absorbs nitrous oxide as well as all other gases; and it -is disengaged from it by heat.</p> - -<p>I have as yet found no other solid body, not possessed of alkaline -properties, capable of absorbing nitrous oxide in any state of -existence.</p> - -<p>The bodies possessing the strongest affinity for oxygene, the dry -sulphites, muriate of tin, the common sulphures, white prussiate of -<span class="pagenum" id="Page_248">[Pg 248]</span> -potash, and green oxide of iron, do not in the slightest degree act on -nitrous oxide at common temperatures.</p> - -<p id="RII_DI_05" class="f120 space-above1">V. <i>Action of different -Gases on Nitrous Oxide.</i></p> - -<p><i>a.</i> 12 measures of muriatic acid gas were mingled with 7 measures -of nitrous oxide at 56°. After remaining together for a minute, they -filled a space equal to 19½ measures. When water was introduced to -them, the muriatic acid was absorbed much more slowly than if it had -been unmingled.</p> - -<p>In another experiment, when the gases were saturated with water, 9 -measures of each of them, when mingled and suffered to remain in -contact for a quarter of an hour, filled a space nearly equal to 19; -and after the muriatic acid had been absorbed by potash, the nitrous -oxide remained unaltered in its properties.</p> - -<p>From the expansion, it appears most probable that aëriform muriatic -acid, and nitrous oxide, have a certain affinity for each other, and -<span class="pagenum" id="Page_249">[Pg 249]</span> -that they combine when mingled together; for in the last experiment, -the increase of volume cannot be accounted for by supposing that -nitrous oxide undergoes less change of volume than muriatic acid, -by aëriform combination with water, and that the expansion depended -upon the solution of some of its combined water by the muriatic acid. -That muriatic acid and nitrous oxide have a slight affinity for each -other, likewise appears from the absorption of nitrous oxide by aqueous -solution of muriatic acid.</p> - -<p>Thinking that nitrous oxide might attract muriatic acid from its -solution in water, I exposed a minute quantity of fluid muriatic acid -to nitrous oxide; but no alteration of volume took place in the gas.</p> - -<p><i>b.</i> 6 measures of nitrous oxide were mingled with 11 measures of -sulphureous acid, saturated with water; after remaining at rest for six -minutes, they filled a space nearly equal to 18 measures. Exposed to -water, the sulphureous acid was absorbed, but not nearly so rapidly as -<span class="pagenum" id="Page_250">[Pg 250]</span> -when in a free state. Sulphur burnt with a vivid flame in the residual -nitrous oxide. 7 measures of sulphureous acid were now mingled with -8 of nitrous oxide. They filled a space nearly equal to 15¾, and no -farther expansion took place afterwards.</p> - -<p>From these experiments it appears probable that sulphureous acid, and -nitrous oxide, have some affinity for each other.</p> - -<p><i>c.</i> 11 measures of carbonic acid were mingled with 8 of nitrous -oxide; they filled a space nearly equal to 19 measures. On exposing -the mixture to caustic potash, the carbonic acid was absorbed, and the -nitrous oxide remained pure. Hence it appears that carbonic acid and -nitrous oxide do not combine with each other.</p> - -<p><i>d.</i> Oxygenated muriatic acid, and nitrous oxide, were mingled in -a water apparatus: there was a slight appearance of condensation; but -this was most probably owing to absorption by the water; on agitation, -the oxygenated muriatic acid was absorbed, and the greater part of the -nitrous oxide remained unaltered. -<span class="pagenum" id="Page_251">[Pg 251]</span></p> - -<p><i>e.</i> Sulphurated hydrogene and nitrous oxide, mingled together, -neither expanded or contracted; exposed to solution of potash, the -acid<a id="FNanchor_154" href="#Footnote_154" class="fnanchor">[154]</a> -only was absorbed.</p> - -<p><i>f.</i> 10 measures of nitrous gas were admitted to 12 of nitrous -oxide at 59°. They filled a space equal to 22, and after remaining -together for an hour, had undergone no change. Solution of muriate of -iron absorbed the nitrous gas without affecting the nitrous oxide.</p> - -<p><i>g.</i> Nitrous oxide was successively mingled with oxygene, -atmospheric air, hydrocarbonate, phosphorated hydrogene, hydrogene, -and nitrogene, at 57°; it appeared to possess no action on any of them, -and was separated by water, the gases remaining unaltered.</p> - -<p><i>h.</i> As nitrous oxide was soluble in ether, alcohol, and the other -inflammable fluids, it was reasonable to suppose that its affinity for -<span class="pagenum" id="Page_252">[Pg 252]</span> -those bodies would enable them to unite with it in the aëriform state. -At the suggestion of Dr. Beddoes I made the following experiment:</p> - -<p>To 12 measures of nitrous oxide, at 54°, I introduced a single drop of -ether; the gas immediately began to expand, and in four minutes filled -a space equal to sixteen measures and a quarter. When an inflamed taper -was plunged into the gas thus holding ether in solution, a light blue -flame slowly passed through it.</p> - -<p>A considerable diminution of temperature is most probably produced, -from the great expansion of nitrous oxide during its combination with -ether.</p> - -<p>A drop of alcohol was admitted to 14 measures of nitrous oxide. In five -minutes, the gas filled a space equal to fifteen and a third; but no -farther diminution took place afterwards.</p> - -<p>A minute quantity of oil of turpentine was introduced to 14 measures -of nitrous oxide; it filled, in 4 minutes, a space rather less than -14; and no farther change took place afterwards. Most likely this -contraction arose from the precipitation of the water dissolved in the -<span class="pagenum" id="Page_253">[Pg 253]</span> -gas by the stronger affinity of the oil for nitrous oxide. To ascertain -with certainty if any oil had been dissolved by the gas, I introduced -into it a small quantity of ammoniac. It immediately became slightly -clouded, most probably from the formation of soap, by the combination -of the dissolved oil with the ammoniac.</p> - -<p>From these experiments we learn, that when nitrous oxide is mingled -with either carbonic acid, oxygene, common air, hydrocarbonate, -sulphurated hydrogene, hydrogene, or nitrogene, they may be separated -from each other without making any allowance for contraction or -expansion; but if a mixture of either muriatic acid, or sulphureous -acid gas, with nitrous oxide, is experimented upon; in the absorption -of the acid by alkalies, the apparent volume of gas condensed will be -less than the real one, by a quantity equal to the sum of expansion -from combination. Consequently a correction must be made on account of -this circumstance.</p> - -<p>Though alcohol, ether, essential oils, and the fluid inflammable -<span class="pagenum" id="Page_254">[Pg 254]</span> -bodies in general, dissolve nitrous oxide with much greater rapidity -than water, yet as we are not perfectly acquainted with their action on -unabsorbable gases, it is better to employ water for separating nitrous -oxide from these substances; particularly as that fluid is more or less -combined with all gases, and as we are acquainted with the extent of -its action upon them.</p> - -<p>By pursuing the subject of the solution of essential oils in gases, -we may probably discover a mode of obtaining them in a state of -absolute dryness. For if other gases as well as nitrous oxide, have a -stronger affinity for oils than for water, water most probably will -be precipitated from them during their solution of oils; and after -their saturation with oil, it is likely that they are capable of being -deprived of that substance by ammoniac.</p> - -<p id="RII_DI_06" class="f120 space-above1">VI. <i>Action of aëriform -Nitrous Oxide in the Alkalies.<br /> History of the discovery of the -combinations<br />of Nitrous Oxide with the Alkalies.</i></p> - -<p><span class="pagenum" id="Page_255">[Pg 255]</span> -<i>a.</i> When nitrous oxide in a free state is exposed to the solid -caustic alkalies and alkaline earths, at common temperatures, it is -neither absorbed nor acted upon; when it is placed in contact with -solutions of them in water, a small quantity is dissolved; but this -combination appears to depend on the water of the solution, for the gas -can be expelled unaltered, at the temperature of ebullition.</p> - -<p><i>b.</i> Caustic potash was exposed to nitrous oxide for 13 hours: -the diminution was not to one fiftieth, and this slight condensation most -probably depended upon its combination with the water of the gas.</p> - -<p>Concentrated solution of potash absorbed a fourth of its bulk of -nitrous oxide. When the impregnated solution was heated, globules of -gas were given out from it rapidly; but the quantity collected was too -small to examine.</p> - -<p>Soda, whether solid or in solution, exhibited exactly the same -phænomena with nitrous oxide. The solution of soda absorbed near a -quarter of its bulk of gas. -<span class="pagenum" id="Page_256">[Pg 256]</span></p> - -<p><i>c.</i> 11 measures of ammoniacal gas were mingled with 8 measures of -nitrous oxide over dry mercury, both of the gases being saturated with -water. No change of appearance was produced by the mixture, and they -filled, after two minutes, a space equal to 19. On the introduction -of a little water, the ammoniac was absorbed, and the nitrous oxide -remained unaltered, for it was dissolved by water as rapidly as if it -had never been mingled with ammoniac.<a id="FNanchor_155" href="#Footnote_155" class="fnanchor">[155]</a></p> - -<p>7 measures of nitrous oxide, exposed to 6 measures of solution of -ammoniac in water, was in an hour diminished to 4½ nearly. When the -solution was heated over mercury, permanent gas was produced, which -was unabsorbable by a minute quantity of water, and soluble in a large -quantity; consequently it was nitrous oxide. -<span class="pagenum" id="Page_257">[Pg 257]</span></p> - -<p><i>d.</i> Nitrous oxide was exposed to dry caustic strontian; it -underwent a diminution of nearly one fortieth, which most likely was -owing to the combination of the strontian with its water.</p> - -<p>11 measures of nitrous oxide were agitated in contact with 8 of -strontian lime water: nearly 4 measures were absorbed. The impregnated -solution exposed to heat, rapidly gave out its gas; 3 measures were -soon collected, which mingled with a small quantity of hydrogene, and -inflamed by the taper, gave a smart detonation.</p> - -<p><i>e.</i> Nitrous oxide exposed to lime and argil, both wet and dry, -was not in the slightest degree acted upon.</p> - -<p>From these experiments it is evident that nitrous oxide in the aëriform -state cannot be combined either with the alkalies, or the alkaline -earths. That a combination may be effected between nitrous oxide and -these substances, it must be presented to them, in the <i>nascent -state</i>.</p> - -<p>The salts composed of the alkalies and nitrous oxide, are not -<span class="pagenum" id="Page_258">[Pg 258]</span> -analogous to any other compound substances, being possessed of very -singular properties. Before these properties are detailed, it may not -be amiss to give an account of the accidental way in which I discovered -the mode of combination.</p> - -<p>In December, 1799, designing to make a very delicate experiment, with -a view to ascertain if any water was decomposed during the conversion -of nitrous gas into nitrous oxide, by sulphite of potash, I exposed -200 grains of crystalised sulphite of potash, containing great -superabundance of alkali, to 14 cubic inches of nitrous gas, containing -one eighteenth nitrogene. The alkali was employed to preserve any -ammoniac that might be formed, in the free state, as it would otherwise -combine with sulphureous acid.<a id="FNanchor_156" href="#Footnote_156" class="fnanchor">[156]</a></p> - -<p>The volume of gas diminished with great rapidity; in two hours and ten -<span class="pagenum" id="Page_259">[Pg 259]</span> -minutes it was reduced to 6⁴/₅, which I considered as the limit of -diminution. Accidentally, however, suffering it to remain for three -hours longer, I was much surprised by finding that not quite 2 cubic -inches remained, which consisted of nitrous oxide, mingled with the -nitrogene that existed before the experiment.</p> - -<p>In accounting theoretically for this phænomenon, different suppositions -necessarily presented themselves.</p> - -<p>1st, It was possible, that though sulphite of potash, and potash, -separately possessed no action on free nitrous oxide, yet in -combination they might exert such affinities upon it as either to -absorb it, or make it enter into new combinations.</p> - -<p>2dly. It was more probable that the caustic potash, though incapable -of condensing aëriform nitrous oxide, was yet possessed of a strong -affinity for it when in the <i>nascent state</i>, and that the nitrous -oxide condensed in the experiment had been combined in this state with -the free alkali. -<span class="pagenum" id="Page_260">[Pg 260]</span></p> - -<p>To ascertain if the compound of potash and sulphite of potash with -sulphate, was capable of acting upon nitrous oxide, I suffered a -quantity of this substance to remain in contact with the gas for near a -day: no change whatever took place.</p> - -<p>To determine whether the diminution of nitrous oxide depended upon its -absorption in the nascent state, by the peculiar compound of potash and -sulphite of potash, or if it was simply owing to the alkali.</p> - -<p>I mingled a solution of sulphite of potash with caustic soda; the -salt, after being evaporated at a low temperature, was exposed to -nitrous gas. The nitrous oxide formed was absorbed, but in rather less -quantities than when alkaline sulphite of potash was employed.</p> - -<p>Hence it was evident that the alkali was the agent that had condensed -the nitrous oxide in those experiments, for soda is incapable of -combining either with sulphate, or sulphite of potash.</p> - -<p>To ascertain whether any change in the constitution of the nitrous -<span class="pagenum" id="Page_261">[Pg 261]</span> -oxide had been produced by the condensation, I introduced a small -quantity of sulphite of potash, with excess of alkali, that had -absorbed nitrous oxide, into a long and thin cylindrical tube filled -with mercury; and inclining it at an angle of 35° with the plane of the -mercury, applied the heat of a spirit lamp to that part of the tube -containing the salts; when the glass became very hot, gas was given out -with rapidity; in less than a minute the tube was full. This gas was -transfered into another tube, and examined; it proved to be nitrous -oxide in its highest state of purity;<a id="FNanchor_157" href="#Footnote_157" class="fnanchor">[157]</a> -for a portion of it absorbed by common water, left no more than a -residuum of ¹/₁₅, and sulphur burnt in it with a vivid rose-colored flame.</p> - -<p>Being now satisfied that the alkalies were capable of combining with -nitrous oxide; to investigate with precision the nature of these new -compounds, I proceeded in the following manner. -<span class="pagenum" id="Page_262">[Pg 262]</span></p> - -<p id="RII_DI_07" class="f120 space-above1">VII. <i>Combination of -Nitrous Oxide with Potash.</i></p> - -<p><i>a.</i> Into a solution of sulphite of potash, which had been made by -passing sulphureous acid gas from a mercurial airholder into caustic -potash dissolved in water, I introduced 17 grains of dry potash. The -whole evaporated at a low temperature, gave 143 grains of salt. This -salt was not <i>wholly</i> composed of sulphite of potash and potash; -it contained as well, a minute quantity of carbonate, and sulphate of -potash, formed during the evaporation.<a id="FNanchor_158" href="#Footnote_158" class="fnanchor">[158]</a></p> - -<p>120 grains of it finely pulverised, and retaining the water of -crystalisation, were exposed to 15 cubic inches of nitrous gas, over -mercury. The nitrous gas diminished with great rapidity, and in three -<span class="pagenum" id="Page_263">[Pg 263]</span> -hours a cubic inch and nine tenths only remained, which consisted of -nearly one third nitrous oxide, and two thirds nitrogene that had -pre-existed in the nitrous gas. The increase of weight of the salt -could not be determined, as some of it was lost by adhering to the -vessel in which the combination was effected, and to the mercury. It -presented no distinct series of crystalisations, even when examined -by the magnifier; rendered green vegetable blues, and its taste was -very different from that of the remaining quantity of salt that had -been exposed to the atmosphere. A portion of it strongly heated over -mercury, gave out gas with great rapidity, which had all the properties -of the purest nitrous oxide.</p> - -<p>When water was poured upon some of it, no gas was given out, and the -whole was equably and gradually dissolved. Alcohol, as well as ether, -appeared incapable of dissolving any part of it.</p> - -<p>When muriatic acid was introduced into it, confined by mercury, a -rapid effervescence took place. Part of the gas disengaged was -<span class="pagenum" id="Page_264">[Pg 264]</span> -sulphureous acid, and carbonic acid; the remainder was nitrous oxide.</p> - -<p><i>b.</i> I made a number of experiments upon salts procured in the -manner I have just described, with a view to obtain the compound of -nitrous oxide and potash, free from admixture of other salts.</p> - -<p>When the mixed salt was boiled in alcohol or ether, no part of it -appeared to be dissolved. Finding that little or no gas was given out -during the ebullition of concentrated solutions of the mixed salts, -I attempted to separate the sulphate, sulphite, and carbonate of -potash, from the combination of nitrous oxide and potash, by successive -evaporations and crystalisations. But though in this way it was nearly -freed from sulphate of potash, yet the extreme and nearly equal -solubility of the other salts, prevented me from completely separating -them from each other.</p> - -<p>By exposing, however, very finely pulverised sulphite of potash, -mingled with alkali, for a great length of time to nitrous gas, it was -<span class="pagenum" id="Page_265">[Pg 265]</span> -almost wholly converted into sulphate; and after the separation of -this solution, evaporation, and crystalisation, at a low temperature, -I obtained the new combination, mingled with very little carbonate of -potash, and still less of sulphite.</p> - -<p>The minute quantity of sulphite chiefly appeared in very small -crystals; distinct from the mass of salt, which possessed no regular -crystalisation, and was almost wholly composed of the new compound, -intimated mingled with a little carbonate. The new compound, as nearly -as I could estimate from the quantity of nitrous oxide absorbed, -consisted of about 3 alkali, to 1 of nitrous oxide, by weight.</p> - -<p>It exhibited the following properties:</p> - -<div class="blockquot"> -<p>1. Its taste was caustic, and possessed of a pungency different from -either potash or carbonate of potash.</p> - -<p>2. It rendered vegetable blues green, which might possibly depend upon -the carbonate of potash mixed with it.</p> - -<p>3. Pulverised charcoal mingled with a few grains of it, and inflamed, -<span class="pagenum" id="Page_266">[Pg 266]</span> -burnt with flight scintillations. Projected into zinc in a state of -fusion, a slight inflammation was produced.</p> - -<p>4. When either sulphuric, muriatic, or nitric acid was introduced to -it under mercury, it gave out nitrous oxide, mingled with a little -carbonic acid.</p> - -<p>5. Thrown into a solution of sulphurated hydrogene, gas was disengaged -from it, but in quantities too minute to be examined.</p> - -<p>6. When carbonic acid was thrown into a solution of it in water, gas -was disengaged; on examination it proved to be nitrous oxide.</p> - -<p>7. A concentrated solution of it kept in ebullition in a cylinder, -confined by mercury, gave out a few globules of gas, which were too -minute to be examined, and probably consisted of common air previously -contained in the water.</p> -</div> - -<p><i>c.</i> In the experiments made to ascertain these properties all -the salt was expended, otherwise I should have endeavoured to ascertain -what quantity of gas would have been liberated by heat from a given -<span class="pagenum" id="Page_267">[Pg 267]</span> -weight; and likewise what would have been the effects of admixture -of it with oil. When some of the mixed salt was mingled with oil of -turpentine, part of it was dissolved, and the fluid became white; but -no gas was given out. On this coarse experiment, however, I cannot -place much dependance. If the combination of nitrous oxide and potash -is capable of combining with oil without decomposition, barytes and -strontian<a id="FNanchor_159" href="#Footnote_159" class="fnanchor">[159]</a> -will probably separate the oil from it, and thus it may -possibly be obtained in a state of purity.</p> - -<p>In a rough experiment made on the conversion of nitrous gas into -nitrous oxide, by concentrated solution of sulphite of potash with -excess of alkali, very little of the nitrous oxide was absorbed. Hence -it is probable that water lessens the affinity of potash for nascent -nitrous oxide. -<span class="pagenum" id="Page_268">[Pg 268]</span></p> - -<p id="RII_DI_08" class="f120 space-above1">VIII. <i>Combination of -Nitrous Oxide with Soda.</i></p> - -<p>The union of nitrous oxide with soda is effected in the same manner -as with potash. The alkali, mingled by solution and evaporation, with -either sulphite of soda, or of potash, is exposed to nitrous gas; the -nitrous oxide is condensed by it at the moment of generation, and the -combination effected.</p> - -<p>As far as I have been able to observe, nitrous oxide is not absorbed to -so great an extent by soda, as potash.</p> - -<p>I have not yet been able to obtain the combination of nitrous -oxide with soda in its pure state. To the attainment of this end, -difficulties identical with those noticed in the last section present -themselves. It is extremely difficult to procure the soda perfectly -free from carbonic acid, and though by using sulphite of potash -the sulphate formed is easily separated, yet still evaporation and -<span class="pagenum" id="Page_269">[Pg 269]</span> -crystalisation will not disengage the sulphite and carbonate from the -new compound.</p> - -<p>The compound of soda and nitrous oxide, mingled with a little sulphite -and carbonate of soda, was rapidly soluble, both in warm and cold -water, without effervescence. Its solution, heated to ebullition, gave -out no gas. The taste of the solid salt was caustic, and more acrid -than that of the mixture of carbonate and sulphite of soda. When cast -upon zinc in fusion, it burnt with a white flame. When heated to 400° -or 500°, it gave out nitrous oxide with rapidity. Nitrous oxide was -expelled from it by the sulphuric, muriatic, and carbonic acids, <i>I -believe</i>, by sulphurated hydrogene.<a id="FNanchor_160" href="#Footnote_160" class="fnanchor">[160]</a></p> - -<p id="RII_DI_09" class="f120 space-above1">IX. <i>Combination of -Nitrous Oxide with Ammoniac.</i></p> - -<p><span class="pagenum" id="Page_270">[Pg 270]</span> -I attempted to effect this combination by converting nitrous gas into -nitrous oxide, by sulphite of ammoniac, wetted with strong solution of -caustic ammoniac; but without success; for the whole of the nitrous -oxide produced remained in a free state.</p> - -<p>When I exposed sulphite of potash, mingled by solution and evaporation -with highly alkaline carbonate of ammoniac,<a id="FNanchor_161" href="#Footnote_161" class="fnanchor">[161]</a> -to nitrous gas, the diminution was nearly one fourth more than if pure -sulphite of potash had been employed. Hence it appears most likely that -ammoniac is capable of combination with nitrous oxide in the nascent state.</p> - -<p>In the experiments on the conversion of nitrous gas into nitrous oxide, -by nascent hydrogene, and by sulphurated hydrogene, <a href="#RI_DIV_V">Res. I. Divis. V</a>. -<span class="pagenum" id="Page_271">[Pg 271]</span> -probably the water formed at the same time with the ammoniac and -nitrous oxide, prevented them from entering into combination; -<i>possibly</i> the peculiar compound was formed, but in quantities so -minute as not to be distinguished from simple ammoniac;<a id="FNanchor_162" href="#Footnote_162" class="fnanchor">[162]</a> -for even the existence of ammoniac in these processes, is but barely perceptible.</p> - -<p>If it should be proved by future experiments, that in the decomposition -of nitrous gas by nascent hydrogene, a peculiar compound of nitrous -oxide, water and ammoniac, is formed, it will afford proofs in favor of -the doctrine of predisposing affinity;<a id="FNanchor_163" href="#Footnote_163" class="fnanchor">[163]</a> -for then this decomposition might be supposed to depend upon the -disposition of oxygene, hydrogene and nitrogene to assume the states -of combination in which they might form a triple compound, of water, -nitrous oxide, and ammoniac. -<span class="pagenum" id="Page_272">[Pg 272]</span></p> - -<p>Nitrous oxide might probably be made to combine with ammoniac by -exposing a mixture of nitrous gas and aëriform ammoniac, to the -sulphites.</p> - -<p>It is probable that nitrous oxide may be combined with ammoniac, -by means of double affinity. Perhaps sulphate of ammoniac and the -combination of potash with nitrous oxide mingled together in solution, -would be converted into sulphate of potash and the compound of nitrous -oxide, and ammoniac. -<span class="pagenum" id="Page_273">[Pg 273]</span></p> - -<p id="RII_DI_10" class="f120 space-above1">X. <i>Probability of forming -Compounds of Nitrous Oxide<br /> and the Alkaline Earths.</i></p> - -<p>I attempted to combine nitrous oxide with lime and strontian, by -exposing sulphites of lime and strontian with excess of earth, to -nitrous gas; but this process did not succeed: the diminution took -place so slowly as to destroy all hopes of gaining any results in -a definite time. Sulphite of potash is decomposable by barytes, -strontian, and lime;<a id="FNanchor_164" href="#Footnote_164" class="fnanchor">[164]</a> -consequently it was impossible to employ this substance to effect the -combination.</p> - -<p>As the dry sulphures, when well made, convert nitrous gas into nitrous -oxide, it is probable that the union of the earths with nascent nitrous -oxide may be effected by exposing nitrous gas to their sulphures, -containing an excess of earth. -<span class="pagenum" id="Page_274">[Pg 274]</span></p> - -<p>Perhaps the combination of nitrous oxide with strontian may be effected -by introducing the combination of potash and nitrous oxide into -strontian lime water.</p> - -<p>It is probable that nitrous oxide may be combined with clay and -magnesia, by exposing these bodies, mingled with sulphite of potash or -soda, to nitrous gas.</p> - -<p id="RII_DI_11" class="f120 space-above1">XI. <i>Additional Observations -on the combinations<br /> of Nitrous Oxide with the Alkalies.</i></p> - -<p>A desire to complete physiological investigations relating to nitrous -oxide, has hitherto prevented me from pursuing to a greater extent, the -experiments on the combination of this substance with the alkalies, &c. -As soon as an opportunity occurs, I purpose to resume the subject.</p> - -<p>The observations detailed in the foregoing sections are sufficient -to show that nitrous oxide is capable of entering into intimate union -with the fixed alkalies: and as the compounds formed by this union are -<span class="pagenum" id="Page_275">[Pg 275]</span> -insoluble in alcohol, decomposable by the acids, and heat, and -possessed of peculiar properties, they ought to be considered as a new -class of saline substances.</p> - -<p>If it is thought proper, on a farther investigation of their -properties, to signify them by specific names, they may, according to -the usually adopted fashion of nomenclature, be called <i>nitroxis</i>: -thus the <i>nitroxi of potash</i> would signify the salt formed by the -combination of nitrous oxide with potash.</p> - -<p>Future experiments must determine the different affinities of nitrous -oxide for the alkalies, and alkaline earths.</p> - -<p>With regard to the uses of these new compounds it is difficult to -form a guess. When they are obtained pure, and fully saturated with -nitrous oxide, on account of the low temperature at which their gas is -liberated, they will probably constitute detonating compounds. From -their facility of decomposition by the weaker acids, they may possibly -be used medicinally, if ever the evolution of nitrous oxide in the -stomach should be found beneficial in diseases. -<span class="pagenum" id="Page_276">[Pg 276]</span></p> - -<p id="RII_DI_12" class="f120 space-above1">XII. <i>The properties -of Nitrous Oxide resemble those of Acids.</i></p> - -<p>If we were inclined to generalise, and to place nitrous oxide among -a known class of bodies, its properties would certainly induce us -to consider it as more analogous to the acids than to any other -substances; for it is capable of uniting with water and the alkalies, -and is insoluble in most of the acids. It differs, however, from the -stronger acids, in not possessing the sour taste,<a id="FNanchor_165" href="#Footnote_165" class="fnanchor">[165]</a> -and the power of reddening vegetable blues: and from both the stronger -and weaker acids, in not being combinable when in a perfectly free -<span class="pagenum" id="Page_277">[Pg 277]</span> -state, at common temperatures, with the alkalies. If it should be -proved by future experiments, that condensation by cold gave it the -capability of immediately forming neutro-saline compounds with the -alkalies; it ought to be considered as the weakest of the acids. -Till those experiments are made, its extraordinary chemical and -physiological properties are sufficient to induce us to consider it as -a body <i>sui generis</i>.</p> - -<p>It is a singular fact that nitrous gas, which contains in its -composition a quantity of oxygene so much greater than nitrous oxide, -should nevertheless possess no acid properties. It is uncombinable with -alkalies, very little soluble in water, and absorbable by the acids. -<span class="pagenum" id="Page_278">[Pg 278]</span></p> - -<h3 id="RII_DIV_II">DIVISION II.</h3> - -<p class="neg-indent"><i>On the DECOMPOSITION of NITROUS OXIDE by -COMBUSTIBLE BODIES. Its ANALYSIS. OBSERVATIONS on the different -combinations of OXYGENE and NITROGENE.</i></p> - -<p id="RII_DII_01" class="f120">I. <i>Preliminaries.</i></p> - -<p class="drop-cap"><span class="smcap">From</span> the phænomena mentioned -in <a href="#RI_DIV_III">Res. I. Divis. III</a>.<a id="FNanchor_166" href="#Footnote_166" class="fnanchor">[166]</a> -it appears that the combustible bodies burn in nitrous oxide at certain -temperatures. The experiments in this Division were instituted for the -purpose of investigating the precise nature of these combustions, with -a view of ascertaining exactly the composition of nitrous oxide.</p> - -<p>It will be seen hereafter that very high temperatures are required for -<span class="pagenum" id="Page_279">[Pg 279]</span> -the decomposition of nitrous oxide, by most of the combustible bodies, -and that in this process heat and light are produced to a very great -extent. These agents alone are possessed of a considerable power of -action on nitrous oxide; of which it is necessary to give an account, -that we may be able to understand the phænomena in the following sections.</p> - -<p id="RII_DII_02" class="f120 space-above1">II. <i>Conversion of Nitrous Oxide -into Nitrous Acid,<br /> and a Gas analogous to Atmospheric Air, by Ignition.</i></p> - -<p><i>a.</i> Dr. Priestley asserts, that nitrous oxide exposed for -a certain time to the action of the electric spark, is rendered -immiscible with water, and capable of diminution with nitrous gas, -without suffering any alteration of volume; and likewise that the -same changes are effected in it by exposure to ignited incombustible -bodies.<a id="FNanchor_167" href="#Footnote_167" class="fnanchor">[167]</a></p> - -<p><span class="pagenum" id="Page_280">[Pg 280]</span> -The Dutch chemists state, that the electric spark passed through -nitrous oxide, occasions a small diminution of its volume, and that the -gas remaining is analogous to common air.<a id="FNanchor_168" href="#Footnote_168" class="fnanchor">[168]</a> -They conclude that this change depends on the separation of its -constituent parts, oxygene and nitrogene, from each other.</p> - -<p>None of these chemists have suspected the production of nitrous acid in -this process.</p> - -<p><i>b.</i> Nitrous oxide undergoes no change whatever from the simple -action of light. I exposed some of it, confined by mercury, for many -days to this agent, often passing through it concentrated rays by -means of a small lens. When examined it appeared, as well as I could -estimate, of the same degree of purity as at the beginning of the experiment.</p> - -<p><i>c.</i> A temperature below that of ignition effects no alteration in -the constitution of nitrous oxide. I passed nitrous oxide from a retort -<span class="pagenum" id="Page_281">[Pg 281]</span> -containing decomposing nitrate of ammoniac, through a green glass -tube, strongly heated in an air-furnace, but not suffered to undergo -ignition. The gas, received in a water apparatus exhibited the same -properties as the purest nitrous oxide; some of it absorbed by water, -left a residuum of not quite one thirteenth.</p> - -<p><i>d.</i> The action of the electric spark for a long while continued, -converts nitrous oxide into a gas analogous to atmospheric air, and -nitrous acid.</p> - -<p>I passed about 150 strong shocks from a small Leyden phial, through 7 -ten grain measures of pure nitrous oxide. After this it filled a space -rather less than six measures: the mercury was rendered white on the -top, as if it had been acted on by nitric acid. Six measures of nitrous -gas mingled with the residual gas of the experiment, over mercury -covered by a little water, gave red fumes, and rapid diminution. In -five minutes the volume of the gases nearly equalled ten. Thermometer -in this experiment was 58°. -<span class="pagenum" id="Page_282">[Pg 282]</span></p> - -<p>Electric sparks were passed for an hour and half through 7 ten grain -measures of nitrous oxide over mercury covered with a little red -cabbage juice, previously saturated with nitrous oxide, and rendered -green by an alkali. After the process the gas filled a space equal -to rather more than six measures and half, and the juice was become -of a pale red. The gas was introduced into a small tube filled with -pure water, and agitated; no absorption was perceptible: 7 measures -of nitrous gas added to it gave red fumes, and after six minutes a -diminution to 9¼ nearly. 6½ measures of common air from the garden, -with 7 of nitrous gas, gave exactly 9.</p> - -<p>In this experiment it was evident that nitrous oxide was converted -into a gas analogous to atmospheric air, at the same time that an acid -was formed. There could be little doubt but that this was the nitrous -acid. To ascertain it, however, with greater certainty, the electric -spark was passed through 6 measures of nitrous oxide, over a little -<span class="pagenum" id="Page_283">[Pg 283]</span> -solution of green sulphate of iron, confined by mercury. As the process -went on, the color of the solution became rather darker. When the -diminution was complete, a little prussiate of iron was added to the -solution. A precipitate of pale blue prussiate of potash was produced.</p> - -<p><i>c.</i> Nitrous oxide was passed from decomposing nitrate of -ammoniac, through a porcelain tube well glazed inside and outside, -strongly ignited in an air-furnace, and communicating with the water -apparatus. The gas collected was rendered opaque by dense red vapor. -It appeared wholly unabsorbable by water. After the precipitation of -its vapor, a candle burnt in it with nearly the same brilliancy as in -atmospheric air. 20 measures of it that had been agitated in water -immediately after its production, mingled with 40 measures of nitrous -gas, diminished to about 47.5; whereas 20 measures that had remained -unagitated for some time after their generation, introduced to the same -quantity of nitrous gas, gave nearly 49. 20 measures of atmospheric -air, with 40 of the same nitrous gas, were condensed to 46. -<span class="pagenum" id="Page_284">[Pg 284]</span></p> - -<p>The water with which the gas had been in contact, was strongly acid. A -little of it poured into a solution of green sulphate of iron, and then -mingled with prussian alkali, produced a green precipitate. Hence the -acid it contained was evidently nitrous.</p> - -<p>That no source of error could have existed in this experiment from -fissure in the tube, I proved, by sending water through it whilst -ignited, after the process, from the same retort in which the nitrate -of ammoniac had been decomposed; a few globules of air only were -produced, not equal to one tenth of the volume of the water boiled, and -which were doubtless previously contained in it.</p> - -<p>I have repeated this experiment two or three times, with similar -results; whenever the air was agitated in water immediately after its -production, it gave <i>almost</i> the same diminution with nitrous gas -as common air; when, on the contrary, it has been suffered to remain -for some time in contact with the phlogisticated nitrous acid suspended -<span class="pagenum" id="Page_285">[Pg 285]</span> -in it, the condensation has been less with nitrous gas by five or -six hundred parts. Hence I am inclined to believe, that if it were -possible to condense all the nitrous acid formed, immediately after -its generation, so as to prevent it from absorbing oxygene from the -permanent gas, this gas would be found identical with the air of the -atmosphere.</p> - -<p>The changes effected by fire on nitrous oxide are not analogous to -those produced by it in other bodies; for the power of this agent seems -generally <i>uniform</i>, either in wholly separating the constituent -principles of bodies from each other, or in making them enter into more -intimate union.<a id="FNanchor_169" href="#Footnote_169" class="fnanchor">[169]</a></p> - -<p>It is a singular phænomenon, that whilst it condenses one part of the -oxygene and nitrogene of nitrous oxide, in the form of nitrous acid; it -<span class="pagenum" id="Page_286">[Pg 286]</span> -should cause the remainder to expand, in the state of atmospheric air. -Does not this fact afford an inference in favor of the <i>chemical</i> -composition of atmospheric air?</p> - -<p id="RII_DII_03" class="f120 space-above1">III. <i>Decomposition of -Nitrous Oxide by Hydrogene,<br /> at the temperature of Ignition.</i></p> - -<p>In the following experiments on the decomposition of nitrous oxide -by hydrogene, the gases were carefully generated in the mercurial -apparatus, and their purity ascertained by the tests mentioned in -<a href="#RES_I">Research I</a>. They were measured in small tubes -graduated to grains, and then transferred into the detonating tube, -which was eight tenths of an inch in diameter, and graduated to ten -grain measures.</p> - -<p>The space occupied by the gases being noted after the inflammation by -the electric shock, green muriate of iron, and prussiate of potash, -were successively introduced, to ascertain if any nitrous acid had been -formed. The absorption, if any took place, was marked, and the gases -<span class="pagenum" id="Page_287">[Pg 287]</span> -transferred into a narrow grain measure tube, and their bulk and -composition accurately ascertained.</p> - -<p><i>b.</i> The hydrogene employed was procured from water by means of -zinc and sulphuric acid. 50 grain measures of it fired by the electric -spark, with 30 grain measures of oxygene containing one eleventh -nitrogene, gave a residuum of about 4. Nitrous gas mingled with those -4, indicated the presence of rather less than 1 of unconsumed oxygene. -In another experiment 23 of it, with 20 of the same oxygene left rather -more than 6 residuum.</p> - -<p>The nitrous oxide was apparently pure, for it left a remainder of about -,05 only, when absorbed by common water.</p> - -<p><i>c.</i> 30 of hydrogene were fired with 40 of nitrous oxide; the -concussion was very great, and the light given out bright red; no -perceptible quantity of nitrous acid was formed; the residual gas -filled a space equal to 52. No part of it was absorbable by water, it -gave no diminution with nitrous gas, when it was mingled with a little -<span class="pagenum" id="Page_288">[Pg 288]</span> -oxygene, and again acted on by the electric spark, an inflammation and -slight diminution was produced.</p> - -<p><i>d.</i> 33 of hydrogene were fired with 35 of nitrous oxide: nitrous -acid was produced in very minute quantity; the gas that remained was -not absorbable by water, and filled a space equal to 37 grains. Nitrous -gas mingled with these, underwent a very slight diminution.</p> - -<p><i>e.</i> 46 hydrogene were fired with 46 nitrous oxide. The quantity -of nitrous acid formed was just sufficient to tinge the white prussiate -of potash. The gases filled a space equal to 49, gave no perceptible -diminution with nitrous gas, and did not inflame with oxygene.</p> - -<p><i>f.</i> 40 hydrogene were fired with 39 nitrous oxide; no perceptible -quantity of nitrous acid was formed. The residual gas filled a space -equal to 41; was unabsorbable by water, underwent no diminution when -mingled with nitrous gas; or when acted on by the electric spark in -contact with oxygene.</p> - -<p><i>g.</i> 20 hydrogene were fired with 64 nitrous oxide; after -<span class="pagenum" id="Page_289">[Pg 289]</span> -detonation the expansion of the gases was greater in this experiment -than any of the preceding ones; dense white fumes were observed in -the cylinder, and a slow contraction of volume took place. After a -little green muriate of iron had been admitted, the gases filled a -space equal to 73: prussiate of potash mingled with the muriate, gave a -deeper blue than in any of the preceding experiments. The residual gas -was unabsorbable by water: 65 of it, mingled with 65 of nitrous gas, -diminished to 93; whilst 65 of common air, with 65 of nitrous gas, gave 84.</p> - -<p><i>h.</i> 8 of hydrogene were fired with 54 of nitrous oxide; the same -phænomena as were observed in the last experiment took place; nitrous -acid was formed; after the absorption of which the residual gas filled -a space equal to 55. 50 of this, with an equal quantity of nitrous gas, -diminished to 76. In these processes the temperatures were from 56° to 61°.</p> - -<p>These experiments are selected as the most accurate of nearly fifty, -<span class="pagenum" id="Page_290">[Pg 290]</span> -made on the inflammation of different quantities of nitrous oxide and -hydrogene.</p> - -<p>As Mr. Keir found muriatic acid in the fluid, produced by the -inflammation of oxygene and hydrogene in closed vessels, in Dr. -Priestley’s experiments, I preserved the residual gas of about 3 cubic -inches of nitrous oxide, that had been detonated at different times -with less than a cubic inch and half of hydrogene; but solution of -nitrate of silver was not clouded when agitated in this gas, nor when -introduced into the detonating tube in which the inflammation had been -made.</p> - -<p>From these experiments we learn that nitrous oxide is decomposable at -the heat of ignition, by hydrogene, in a variety of proportions.</p> - -<p>When the quantity of hydrogene very little exceeds that of the nitrous -oxide, both of the gates disappear, water is produced, no nitrous acid -is formed, and the volume of nitrogene evolved is rather greater than -that of the nitrous oxide decomposed. -<span class="pagenum" id="Page_291">[Pg 291]</span></p> - -<p>When the quantity of hydrogene is less than that of the nitrous oxide, -water, nitrous acid, oxygene and nitrogene, are generated in different -proportions; one part of the nitrous oxide is most probably wholly -decomposed by the hydrogene, and the other part converted into nitrous -acid and atmospheric air, in consequence of the ignition.</p> - -<p>From experiments <i>c</i>, <i>d</i>, and <i>e</i>, the composition of -nitrous oxide may be deduced. In experiment <i>d</i>, 39 of nitrous -oxide were decomposed by 40 of hydrogene, and converted into 41 of nitrogene.</p> - -<p>Now from <i>b</i> it appears that 40 of hydrogene require for their -condensation about 20.8 of oxygene in volume; so that founding the -estimation upon the quantity of hydrogene consumed, 100 parts of -nitrous oxide would consist nearly of 63.1 of nitrogene, and 36.9 of -oxygene. But 41 of nitrogene weigh 12.4, <a href="#RI_DIV_I">Res. I. Div. I</a>. -Consequently, deducing the composition of nitrous oxide from the quantity of nitrogene -evolved, 100 parts of it would consist of 63.5 nitrogene, and 36.5 oxygene. -<span class="pagenum" id="Page_292">[Pg 292]</span></p> - -<p>These estimations are very little different from those which may be -deduced from the other experiments, and the coincidence is in favor of -their accuracy.</p> - -<p>From the following experiment it appears that the temperature required -for the decomposition of nitrous oxide by hydrogene must be higher -than that which is necessary to produce the inflammation of hydrogene -with oxygene. I introduced into small tubes filled with equal parts of -nitrous oxide and hydrogene, standing on a surface of mercury, iron -wires ignited to different degrees, from the dull red to the vivid -white heat. The gases were always inflamed by the white and vivid -red heats; but never by the dull red heat, though the last uniformly -inflamed mixtures of oxygene and hydrogene, and atmospheric air and -hydrogene.</p> - -<p>Dr. Priestley<a id="FNanchor_170" href="#Footnote_170" class="fnanchor">[170]</a> -first detonated together nitrous oxide and hydrogene; his experiment was -<span class="pagenum" id="Page_293">[Pg 293]</span> -repeated by the Dutch chemists, who found that when a small quantity of -hydrogene was employed, the nitrous oxide was partially converted into -a gas analogous to common air. Their estimation of its composition, -which is not far removed from the truth, was founded on this -phænomenon.<a id="FNanchor_171" href="#Footnote_171" class="fnanchor">[171]</a></p> - -<p id="RII_DII_04" class="f120 space-above1">IV. <i>Decomposition of -Nitrous Oxide by Phosphorus.</i></p> - -<p><i>a.</i> Phosphorus introduced into pure nitrous oxide at common -temperatures, is not at all luminous. It is capable of being fused, -and even sublimed in it, without undergoing acidification, and without -effecting any alteration in its composition.</p> - -<p>About 2 grains of phosphorus were fused, and gradually sublimed, in 2 -cubic inches of pure nitrous oxide, over mercury, by the heat of a -<span class="pagenum" id="Page_294">[Pg 294]</span> -burning lens. No alteration was produced in the volume of gas, and a -portion of it absorbed by water, left a residuum of one twelfth only.</p> - -<p>Phosphorus was sublimed in pure nitrous oxide over mercury, in a dark -room, by an iron heated <i>nearly</i> to ignition; but no luminous -appearance was perceptible, nor was any gas decomposed.</p> - -<p><i>b.</i> Phosphorus decomposes nitrous oxide at the temperature of -ignition, with greater or less rapidity, according to the degree of -heat. We have already seen, that when phosphorus in active inflammation -is introduced into nitrous oxide, it burns with intensely vivid light.</p> - -<p>Phosphorus was sublimed by a heated wire in a jar filled with nitrous -oxide, standing over warm mercury. In this state of sublimation an iron -heated dull red was introduced to it by being rapidly passed through -the mercury; a light blue flame surrounded the wire, and disappeared as -soon as it ceased to be red.</p> - -<p>To phosphorus sublimed as before, in nitrous oxide, over warm mercury, -<span class="pagenum" id="Page_295">[Pg 295]</span> -a thick wire ignited to whiteness was introduced; a terrible detonation -took place, and the jar was shattered in pieces.</p> - -<p>By employing thick conical jars,<a id="FNanchor_172" href="#Footnote_172" class="fnanchor">[172]</a> -containing only a small quantity of nitrous oxide, I effected the -detonation several times with safety; but on account of the great -expansion of the elastic products, the jar was generally either raised -from the mercury, or portions of gas were thrown out of it. Hence I -was unable to ascertain the exact changes produced by this mode of -decomposition.</p> - -<p><i>c.</i> As my first attempts to ascertain the constitution of nitrous -oxide were made on its decomposition by phosphorus, I employed many -<span class="pagenum" id="Page_296">[Pg 296]</span> -different modes of partially igniting this substance in it over -mercury, so as to produce a combustion without explosion.</p> - -<p>The first method adopted was inflammation by means of oxygenated -muriate of potash. A small particle of oxygenated muriate of potash was -inserted into the phosphorus to be burnt. On the application of a wire, -moderately hot, to the point of insertion, the salt was decomposed by -the phosphorus, and sufficient fire generated and partially applied -by the slight explosion, to produce the combustion of the phosphorus, -without the previous sublimation of any part of it.</p> - -<p>The second way employed was the ignition of a part of the phosphorus, -by means of the combustion of a small portion of tinder of cotton,<a id="FNanchor_173" href="#Footnote_173" class="fnanchor">[173]</a> -or paper, in contact with it, by the burning glass.</p> - -<p>The third, and most successful mode, was by introducing into the -<span class="pagenum" id="Page_297">[Pg 297]</span> -graduated jar containing the nitrous oxide, the phosphorus in a small -tube containing oxygene, so balanced as to swim on the surface of the -mercury, without communicating with the nitrous oxide. The phosphorus -was fired in the oxygene with an ignited iron wire, by which at the -moment of combustion, the tube containing it was raised into the -nitrous oxide, and thus the inflammation continued.</p> - -<p><i>d.</i> In different experiments, made with accuracy, I found that -the whole of a quantity of nitrous oxide was never decomposable by -ignited phosphorus; the combustion always stopped when the nitrous -oxide remaining was to the nitrogene evolved as about 1 to 5; likewise -that the volume of nitrogene produced was rather less than that of -the nitrous oxide decomposed, and that this deficiency arose from the -formation of nitrous acid by the intense ignition produced during the -process.</p> - -<p>Of one experiment I shall give a detail.</p> - -<p>Temperature being 48°, two cubic inches of pure nitrous oxide, which -<span class="pagenum" id="Page_298">[Pg 298]</span> -had been generated over mercury, were introduced into a jar of the -capacity of 9 cubic inches, graduated to,1 cubic inches, and much -enlarged at the base. A grain of phosphorus was inserted into a small -vessel about one third of an inch long, and half an inch in diameter, -containing about 15 grain measures of very pure oxygene; this vessel, -which swam on the surface of the mercury, was carefully introduced -into the jar containing the nitrous oxide. The phosphorus was fired by -means of a heated wire, and before the oxygene was wholly consumed, the -vessel containing it elevated into the nitrous oxide. The combustion -was extremely vivid and rapid. After the atmospheric temperature was -restored, the gas was rendered opaque by dense white vapor. When this -had been precipitated, and the small vessel removed from the jar, the -gas filled a space nearly equal to 1.9 cubic inches. On introducing to -it a little solution of green muriate of iron, and prussiate of potash, -green prussiate of iron was produced: hence, evidently, nitrous acid -had been formed. -<span class="pagenum" id="Page_299">[Pg 299]</span></p> - -<p>On the admission of pure water, an absorption of rather more than,3 -took place.</p> - -<p>The 16 measures remaining underwent no perceptible diminution with -nitrous gas; the taper plunged into them was instantly extinguished.</p> - -<p>To ascertain if the phosphoric acid produced in the experiments made -under mercury did not in some measure prevent the decomposition of -the whole of the nitrous oxide by the phosphorus, I introduced into a -mixture of 5 nitrogene and 1 nitrous oxide, ignited phosphorus: but it -was immediately extinguished.<a id="FNanchor_174" href="#Footnote_174" class="fnanchor">[174]</a></p> - -<p>The Dutch Chemists found that phosphorus might be fused in nitrous -oxide without being luminous. They assert that phosphorus in a state of -inflammation, introduced into this gas, was immediately extinguished; -though when taken out into the atmosphere, it again burnt of its own -accord.<a id="FNanchor_175" href="#Footnote_175" class="fnanchor">[175]</a> -It is difficult to account for their mistake. -<span class="pagenum" id="Page_300">[Pg 300]</span></p> - -<p id="RII_DII_05" class="f120 space-above1">V. <i>Decomposition of -Nitrous Oxide by<br /> Phosphorated Hydrogene.</i></p> - -<p><i>a.</i> It has been mentioned in <a href="#RII_DIV_I">Res. II. Div. I</a>. -that phosphorated hydrogene and nitrous oxide posses no action on each other, at -atmospheric temperatures.</p> - -<p>Phosphorated hydrogene mingled with nitrous oxide, is capable of being -inflamed by the electric spark, or by ignition.</p> - -<p><i>b. E.</i> 1. 10 grain measures of phosphorated hydrogene, carefully -produced by means of phosphorus and solution of caustic alkali, were -mingled with 52 measures of nitrous oxide. The electric spark passed -through them, produced a vivid inflammation. The elastic products were -clouded with dense white vapor, and after some minutes filled a space -nearly equal to 60. On the introduction of water, no absorption took -place. When 43 of nitrous gas were admitted, the whole diminished to 70. -<span class="pagenum" id="Page_301">[Pg 301]</span></p> - -<p><i>E.</i> 2. 25 of nitrous oxide were fired with 10 of phosphorated -hydrogene, by the electric spark. After detonation<a id="FNanchor_176" href="#Footnote_176" class="fnanchor">[176]</a> -they filled a space exactly equal to 25. On the admission of solution of green -sulphate of iron, and prussiate of potash, no blue or green precipitate -was produced. On the introduction of water, no diminution was -perceived. 25 of nitrous gas mingled with them, gave exactly 50.</p> - -<p><i>E.</i> 3. 10 of nitrous oxide, mingled with 20 of phosphorated -hydrogene, could not be inflamed.</p> - -<p>25 of nitrous oxide, with 20 phosphorated hydrogene, inflamed. The -gas after detonation, was rendered opaque by dense white vapor, and -filled a space nearly equal to 45. No absorption took place when -water was introduced. On admitting a little oxygene no white fumes, -or diminution, was perceived. The electric spark passed through the -mixture, produced an explosion, with great diminution.</p> - -<p><i>c.</i> From <i>E.</i> 1 it appears, that when a small quantity of -<span class="pagenum" id="Page_302">[Pg 302]</span> -phosphorated hydrogene is inflamed with nitrous oxide, both the -phosphorus and hydrogene are consumed; whilst the superabundant -nitrous oxide, is converted into nitrous acid and atmospheric air, -by the ignition; or a certain quantity is partially decomposed into -atmospheric air by the combination of a portion of its oxygene with the -combustible gas.</p> - -<p>From <i>E.</i> 2 we learn, that when the phosphorated hydrogene -and nitrous oxide are to each other as 25 to 10 nearly, they both -disappear, whilst nitrogene is evolved, and water and phosphoric acid -produced. Reasoning concerning the composition of nitrous oxide from -this experiment, we should conclude that it was composed of about 38 -oxygene, and 62 nitrogene.</p> - -<p>The result of <i>E.</i> 3 is interesting; we are taught from it that -the affinity of phosphorus for the oxygene of nitrous oxide is stronger -than that of hydrogene, at the temperature of ignition; so that when -phosphorated hydrogene is mingled with a quantity of nitrous oxide, not -containing sufficient oxygene to burn both its constituent parts, the -phosphorus only is consumed, whilst the hydrogene is liberated. -<span class="pagenum" id="Page_303">[Pg 303]</span></p> - -<p>In repeating the experiments with phosphorated hydrogene that had -remained for some hours in the mercurial apparatus, I did not gain -exactly the same results; for a larger quantity of it was required to -decompose the nitrous oxide, than in the former experiments; doubtless -from its having deposited a portion of its phosphorus. They confirm, -however, the above mentioned conclusions.</p> - -<p>In the course of experimenting, I passed the electric spark, for -a quarter of an hour, through about 60 measures of phosphorated -hydrogene. It underwent no alteration of volume. Phosphorus was -apparently precipitated from it, and it had wholly lost its power of -inflaming, in contact with common air. -<span class="pagenum" id="Page_304">[Pg 304]</span></p> - -<p id="RII_DII_06" class="f120 space-above1">VI. <i>Decomposition of -Nitrous Oxide by Sulphur.</i></p> - -<p>From the phænomena before mentioned,<a id="FNanchor_177" href="#Footnote_177" class="fnanchor">[177]</a> -relating to the combustion of sulphur in nitrous oxide, it was evident -that this gas was only decomposable by it, at a much higher temperature -than common air.</p> - -<p>I introduced into sulphur in contact with nitrous oxide, over mercury -heated to 112°-114°, a wire intensely ignited. It lost much of its heat -in passing through the mercury, but still appeared red in the vessel. -The sulphur rapidly fused, and sublimed without being at all luminous. -This experiment was repeated five or six times, but in no instance -could the combustion of sulphur, by means of the ignited wire, be -effected.</p> - -<p>I inflamed sulphur in nitrous oxide in the same manner as phosphorus; -namely, by introducing it into the small vessel filled with oxygene, -and igniting it by means of the heated wire. In these experiments the -sulphur burnt with a vivid rose-colored light, and much sulphuric, with -a little sulphureous acid, was formed.</p> - -<p>Experimenting in this way I was never, however, able to decompose more -<span class="pagenum" id="Page_305">[Pg 305]</span> -than one third of the quantity of nitrous oxide employed; not only the -nitrogene evolved, but likewise the sulphuric and sulphureous acids -produced, stopping the combustion.</p> - -<p>I found that sulphur in a state of vivid inflammation, when introduced -into a mixture of one fourth nitrogene, and three fourths nitrous -oxide, burnt with a flame very much enlarged, and of a vivid rose -color. In one third nitrogene, and two thirds nitrous oxide, it burnt -feebly with a yellow flame. In equal parts of nitrous oxide and -nitrogene, it was instantly extinguished.</p> - -<p>Sulphur burnt feebly, with a light yellow flame, when introduced -ignited into a mixture of 5 nitrous gas, and 6 nitrous oxide. In one -third nitrous oxide, and two thirds nitrous gas, it was instantly -extinguished. From many circumstances, I am inclined to believe that -sulphur is incapable, at any temperature, of slowly decomposing nitrous -oxide, so as to burn in it with a blue flame, forming sulphureous acid -<span class="pagenum" id="Page_306">[Pg 306]</span> -alone. It appears to attract oxygene from it only when intensely -ignited, so as to form chiefly sulphuric acid, and that with great -rapidity, and vivid inflammation.</p> - -<p id="RII_DII_07" class="f120 space-above1">VII. <i>Decomposition -of Nitrous Oxide by<br /> Sulphurated Hydrogene.</i></p> - -<p><i>a.</i> Though nitrous oxide and sulphurated hydrogene do not act -upon each other at common temperatures, yet they undergo a mutual -decomposition when mingled together in certain proportions, and ignited -by the electric spark.</p> - -<p>From more than twenty experiments made on the inflammation of -sulphurated hydrogene in nitrous oxide, I select the following as the -most conclusive and accurate. The temperature at which they were made -was from 41° to 49°.</p> - -<p><i>b.</i> <i>E.</i> 1. About 35 measures of nitrous oxide were fired -with 10 of sulphurated hydrogene; the expansion during inflammation was -very great, and the flame sky-blue. Immediately after, the gases filled -a space equal to 48 nearly. White fumes were then formed, and they -<span class="pagenum" id="Page_307">[Pg 307]</span> -gradually contracted to 40. On the admission of a little strontian -lime water, a slight absorption took place, with white precipitation; -and the volume occupied by the residual gas nearly equalled 37. On -admitting nitrous gas to these, no perceptible diminution took place.</p> - -<p><i>E.</i> 2. 20 sulphurated hydrogene, with 25 nitrous oxide, could not -be inflamed.</p> - -<p>30 nitrous oxide, with 22 sulphurated hydrogene, could not be inflamed.</p> - -<p>35 nitrous oxide, with 20 sulphurated hydrogene, inflamed with vivid -blue light, and great expansion. After the explosion, the gases filled -exactly the same space as before the experiment; no white fumes were -perceived, and no farther contraction occurred. On the addition of -strontian lime water, a copious precipitation, with diminution, took -place; and the residual gas filled a space nearly equal to 35½.</p> - -<p><i>E.</i> 3. 47 nitrous oxide, and 14 sulphurated hydrogene, inflamed. -After the explosion, the gases filled a space nearly equal to 65; -then white fumes formed, and they gradually diminished to 52. On the -<span class="pagenum" id="Page_308">[Pg 308]</span> -introduction of muriate of strontian, a copious white precipitate was -produced; and on the addition of water, no further absorption took -place. To the residual 52, about 20 of nitrous gas were added; they -filled together a space equal to about 67.</p> - -<p><i>c.</i> In none of the experiments made on the inflammation of -sulphurated hydrogene and nitrous oxide, could I ascertain with -certainty the precipitation of sulphur. In one or two processes the -detonating tube was rendered a little white at the points of contact -with the mercury; but this was most probably owing to the oxydation -of the mercury, either by the heated sulphuric acid formed, or from -nitrous acid produced by the ignition. The presence of nitrous acid I -could not ascertain in these processes by my usual tests, because the -combustion of sulphur over white prussiate of iron, converts it into -light green.</p> - -<p>When I introduced an inflamed taper into about 3 parts of sulphurated -hydrogene, and 2 parts of nitrous oxide, in which proportions they -<span class="pagenum" id="Page_309">[Pg 309]</span> -could not have been fired by the electric spark, a blue flame passed -through them, and much sulphur was deposited on the sides of the -vessel. But this sulphur most probably owed its formation to the -decomposition of a portion of sulphurated hydrogene not burnt, by the -sulphureous acid formed from the combustion of the other portion.</p> - -<p>We may then conclude with probability, that sulphurated hydrogene -and nitrous oxide will not decompose each other, when acted on by the -electric spark, unless their proportions are such as to enable the -whole of the sulphurated hydrogene to be decomposed, so that both of -its constituents may become oxygenated, by attracting oxygene from the -nitrous oxide: likewise, that when the sulphurated hydrogene is at its -<i>maximum</i> of inflammation, the hydrogene and sulphur form with -the whole of the oxygene of nitrous oxide, water and sulphureous acid; -<i>E.</i> 2: whereas at its <i>minimum</i> they produce water, and -chiefly, <i>perhaps</i> wholly, sulphuric acid; at the same time that -the nitrous oxide partially decomposed, is converted into nitrogene, -<span class="pagenum" id="Page_310">[Pg 310]</span> -and a gas analogous to atmospheric air, or into nitrogene, nitrous -acid, and atmospheric air. <i>E.</i> 1. <i>E.</i> 3.</p> - -<p>By pursuing those experiments, and using larger quantities of gas, -we may probably be able to ascertain from them with accuracy, the -composition of sulphuric and sulphureous acids.</p> - -<p>I own I was disappointed in the results, for I expected to have been -able to ascertain from them, the relative affinities of sulphur, and -hydrogene for the oxygene of nitrous oxide, at the temperature of -ignition. I conjectured that nitrous oxide, mingled with excess of -sulphurated hydrogene, would have been decomposed, and one of the -principles of it evolved unaltered, as was the case with phosphorated -hydrogene.</p> - -<p>If we estimate the composition of nitrous oxide from the quantity -of nitrogene produced in <i>E.</i> 2, it is composed of about 61 -nitrogene, and 39 oxygene. -<span class="pagenum" id="Page_311">[Pg 311]</span></p> - -<p id="RII_DII_08" class="f120 space-above1">VIII. <i>Decomposition of -Nitrous Oxide by Charcoal.</i></p> - -<p>An account of the analysis of nitrous oxide by charcoal is given -in <a href="#RI_DIV_III">Res. I. Div. III</a>. I have lately made two -experiments on the combustion of charcoal in nitrous oxide, in which -every precaution was taken to prevent the existence of sources of -error. Of one of these I shall give a detail.</p> - -<p><i>E.</i> Temperature being 51°, about a grain of charcoal, which -had been exposed for some hours to a red heat, was introduced whilst -ignited, under mercury, and transferred into a graduated jar, containing -3 cubic inches of pure nitrous oxide, standing over dry mercury.</p> - -<p>The focus of a burning lens was thrown on the charcoal; it instantly -inflamed, and burnt with great vividness for near a minute, the gas -being much expanded. The focus was continually applied to it for ten -minutes, when the process appeared at an end. The gases, when the -<span class="pagenum" id="Page_312">[Pg 312]</span> -common temperature and pressure were restored, filled a space equal to -4,2 cubic inches.</p> - -<p>On introducing into them a few grain measures of solution of green -muriate of iron, for the double purpose of saturating them with -moisture, and ascertaining if any nitrous acid had been formed, no -change of volume took place; and prussiate of potash gave with the -muriate a white precipitate only.</p> - -<p>On the admission of a small quantity of concentrated solution of -caustic potash, a diminution of the gas slowly took place; when it was -complete the volume equalled about 3.05 cubic inches. By agitation -in well boiled water, about,9 of these were absorbed; the remainder -appeared to be pure nitrogene.</p> - -<p>The difference between the estimation founded upon the nitrogene -evolved, and that deduced from the carbonic acid generated in this -experiment, is not nearly so great as in that <a href="#RI_DIV_III">Res. I. Div. III</a>. -Taking about the mean proportions, we should conclude that nitrous oxide was -composed of about 38 oxygene, and 62 nitrogene. -<span class="pagenum" id="Page_313">[Pg 313]</span></p> - -<p>Charcoal burnt with greater vividness than in common air, in a mixture -of one third nitrogene and two thirds nitrous oxide. In equal parts -of nitrous oxide and nitrogene, its light was barely perceptible. -In one third nitrous oxide, and two thirds nitrogene, it was almost -immediately extinguished.</p> - -<p>As charcoal burns vividly in nitrous gas, when it has been previously -ignited to whiteness, I introduced it into a mixture of equal parts of -nitrous oxide and nitrous gas; it burnt with a deep and bright red.</p> - -<p id="RII_DII_09" class="f120 space-above1">IX. <i>Decomposition of -Nitrous Oxide<br /> by Hydrocarbonate.</i></p> - -<p>Nitrous oxide, and hydrocarbonate, possess no action on each other, -except at high temperatures. When mingled in certain proportions, and -exposed to the electric shock, a new arrangement of their principles -takes place.</p> - -<p><i>E.</i> 1. Temperature being 53°, 35 of nitrous oxide, mingled with -<span class="pagenum" id="Page_314">[Pg 314]</span> -15 of hydrocarbonate, were fired by the electric spark; the -inflammation was very vivid, and the light produced, bright red. After -the explosion, the space occupied by the gases equalled about 60. On -the admission of solution of strontian, a copious white precipitate was -produced, and the gas diminished by agitation, to rather more than 35. -When 36 of nitrous gas were added to these, white fumes appeared and -the whole diminished to 62. When a little muriatic acid was poured on -the white precipitate from the solution of strontian, gas was evolved -from it, and it was gradually dissolved.</p> - -<p><i>E.</i> 2. 22 nitrous oxide were inflamed with 20 hydrocarbonate; -after the explosion, they filled a space equal to 45; when strontian -lime water was introduced, white precipitation took place, and the -diminution was to 31.</p> - -<p>To these 31, 14 of nitrous oxide were admitted, and the electric spark -passed through them; an inflammation took place: carbonic acid was -<span class="pagenum" id="Page_315">[Pg 315]</span> -formed, after the absorption of which, the gas remaining filled a space -equal to 43, and did not diminish with nitrous gas.</p> - -<p>The hydrocarbonate employed in these experiments, was procured from -alcohol by means of sulphuric acid. In another set of experiments made -with less accuracy, the same general results were obtained. Whenever -hydrocarbonate inflamed with nitrous oxide, both its constituents were -oxygenated; in all cases carbonic acid was formed, and in no instance -free hydrogene evolved, or charcoal precipitated.</p> - -<p>In the decomposition of nitrous oxide by hydrocarbonate, the residual -nitrogene is less than in other combustions. This circumstance I am -unable to explain.</p> - -<p>Reasoning from analogy, there can be little doubt, but that when -hydrocarbonate is inflamed with excess of nitrous oxide, it will be -only partially decompounded, or converted into nitrogene, nitrous acid, -and atmospheric air.</p> - -<p>The Dutch Chemists have asserted, that charcoal does not burn in -nitrous oxide, except in consequence of the previous decomposition of -<span class="pagenum" id="Page_316">[Pg 316]</span> -the gas by the hydrogene always contained in this substance; and -likewise, that when hydrocarbonate and nitrous oxide were mingled -together, and fired by the electric spark, the hydrogene only was -burnt, whilst the charcoal was precipitated.</p> - -<p>It is difficult to account for these numerous mistakes. Their theory of -the <i>non-respirability</i> of nitrous oxide was founded upon them. -They supposed that the chief use of respiration was to deprive the -blood of its superabundant carbon, by the combination of atmospheric -oxygene with that principle; and that nitrous oxide was highly fatal to -life, because it was incapable of de-carbonating the blood<a id="FNanchor_178" href="#Footnote_178" class="fnanchor">[178]</a>!!</p> - -<p id="RII_DII_10" class="f120 space-above1">X. <i>Combustion of Iron -in Nitrous Oxide.</i></p> - -<p>I introduced into a jar of the capacity of 20 cubic inches, containing -11 cubic inches of nitrous oxide, over mercury, a small quantity of -<span class="pagenum" id="Page_317">[Pg 317]</span> -fine iron wire twisted together, and having affixed to it a particle -of cork. On throwing the focus of a burning glass on the cork, it -instantly inflamed, and the fire was communicated to the wire, which -burnt with great vividness for some moments, projecting brilliant white -sparks. After it had ceased to burn the gas was increased in volume -rather more than three tenths of an inch. The nitrous acid tests were -introduced, but no acid appeared to have been formed. On exposing the -gas to water, near 4,2 cubic inches were absorbed: the 7,1 remaining -appeared to be pure nitrogene.</p> - -<p>From this experiment it is evident that iron at the temperature of -ignition, is capable of decomposing nitrous oxide; likewise that it -is incapable of burning in it when it contains more than three fifths -nitrogene.</p> - -<p>I attempted to inflame zinc in nitrous oxide, in the same way as iron; -but without success. By keeping the focus of a burning glass upon -some zinc filings, in a small quantity of nitrous oxide, I converted -a little of the zinc into white oxide, and consequently decomposed a -portion of the gas. -<span class="pagenum" id="Page_318">[Pg 318]</span></p> - -<p id="RII_DII_11" class="f120 space-above1">XI. <i>Combustion of -Pyrophorus in Nitrous Oxide.</i></p> - -<p>Pyrophorus, which inflames in nitrous gas, and atmospheric air, at or -even below 40°, requires for its combustion in nitrous oxide a much -higher temperature. It will not burn in it, or alter it, even at 212°.</p> - -<p>I have often inflamed pyrophorus in nitrous oxide over mercury, by -means of a wire strongly heated, but not ignited. The light produced -by the ignition of pyrophorus in nitrous oxide is white, like that -produced by it in oxygene: in nitrous gas it is red.</p> - -<p>When pyrophorus burns out in nitrous oxide, a little increase of the -volume of gas is produced. Strontian lime water agitated in this gas -becomes clouded; but the quantity of carbonic acid formed is extremely -minute. I have never made any delicate experiments on the combustion of -pyrophorus in nitrous oxide. -<span class="pagenum" id="Page_319">[Pg 319]</span></p> - -<p id="RII_DII_12" class="f120 space-above1">XII. <i>Combustion of -the Taper in Nitrous Oxide.</i></p> - -<p>It has been noticed by different experimentalists, that the taper burns -with a flame considerably enlarged in nitrous oxide: sometimes with a -vivid light and crackling noise, as in oxygene; at other times with a -white central flame, surrounded by a feeble blue one.</p> - -<p>My experiments on the combustion of the taper in nitrous oxide, were -chiefly made with a view to ascertain the cause of the double flame.</p> - -<p>When the inflamed taper is introduced into pure nitrous oxide, it burns -at first with a brilliant white light, and sparkles as in oxygene. As -the combustion goes on, the brilliancy of the flame diminishes; it -gradually lengthens, and becomes surrounded with a pale blue cone of -light, from the apex of which much unburnt charcoal is thrown off, in -the form of smoke. The flame continues double to the end of the process. -<span class="pagenum" id="Page_320">[Pg 320]</span></p> - -<p>When the residual gases are examined after combustion, much nitrous -acid is found suspended in them; and they are composed of carbonic -acid, nitrogene, and about one fourth of undecompounded nitrous oxide.</p> - -<p>The double flame depends upon the nitrous acid formed by the ignition; -for it can be produced by plunging the taper into common air containing -nitrous acid vapor, or into a mixture of nitrous oxide and nitrogene, -through which nitrous acid has been diffused. It is never perceived in -the combustion of the taper, till much nitrous acid is formed.</p> - -<p>In attempting to respire some residual gas of nitrous oxide, in which -a taper had burnt out, I found it so highly impregnated with nitrous -acid, as to disable me from even taking it into my mouth.</p> - -<p>The taper burns in a mixture of equal parts nitrous oxide and -nitrogene, at first with a flame nearly the same as that of a candle in -common air; white. Before its extinction the interior white flame, and -exterior blue flame, are perceived. -<span class="pagenum" id="Page_321">[Pg 321]</span></p> - -<p>The taper is instantly extinguished in a mixture of one fourth nitrous -oxide, and three fourths nitrogene.</p> - -<p>In a mixture of equal parts nitrous oxide and nitrous gas, the taper -burns at first with nearly as much brilliancy as in pure nitrous oxide; -gradually the double and feeble flame is produced.</p> - -<p id="RII_DII_13" class="f120 space-above1">XIII. <i>On the Combustion -of different<br /> Compound Bodies in Nitrous Oxide.</i></p> - -<p>All the solid and fluid compound inflammable bodies on which I have -experimented, burn in nitrous oxide, at high temperatures. Wood, -cotton, and paper, are easily inflamed in it by the burning glass. -During their combustion, nitrous acid is always formed, carbonic acid, -and water produced, and nitrogene evolved, rather less in bulk than the -nitrous oxide decomposed.</p> - -<p>I have already mentioned that alcohol and ether are soluble in nitrous -oxide. When an ignited body is introduced into the solution of alcohol, -<span class="pagenum" id="Page_322">[Pg 322]</span> -or ether in nitrous oxide, a slight explosion takes place.</p> - -<p id="RII_DII_14" class="f120 space-above1">XIV. <i>General Conclusions -relating to the Decomposition<br /> of Nitrous Oxide, and to its Analysis.</i></p> - -<p>From what has been said in the preceding sections, it appears that -the inflammable bodies, in general, require for their combustion in -nitrous oxide, much higher temperatures than those at which they burn -in atmospheric air, or oxygene.</p> - -<p>When intensely heated they decompose it, with the production of much -heat and light, and become oxygenated.</p> - -<p>During the combustion of solid or fluid bodies, producing flame, in -nitrous oxide, nitrous acid is generated, most probably from a new -arrangement of principles, analogous to those observed in Sect. II, by -the ignition of that part of the gas not in contact with the burning -substance. Likewise when nitrous oxide in excess is decomcomposed by -<span class="pagenum" id="Page_323">[Pg 323]</span> -inflammable gases, nitrous acid, and sometimes a gas analogous to -common air, is produced, doubtless from the same cause.</p> - -<p>Pyrophorus is the only body that inflames in nitrous oxide, below the -temperature of ignition.</p> - -<p>Phosphorus burns in it with the blue flame, probably forming with its -oxygene only phosphoreous acid at the dull red heat, and with the -intensely vivid flame, producing phosphoric acid at the white heat.</p> - -<p>Hydrogene, charcoal, sulphur, iron, and the compound inflammable -bodies, decompose it only at heats equal to, or above, that of -ignition: <i>probably</i> each a different temperature.</p> - -<p>From the phænomena in Sect. V. it appears, that at the temperature of -intense ignition, phosphorus has a stronger affinity for the oxygene of -nitrous oxide than hydrogene; and reasoning from the different degrees -of combustibility of the inflammable bodies, in mixtures of nitrous -<span class="pagenum" id="Page_324">[Pg 324]</span> -oxide and nitrogene, and from other phænomena, we may conclude with -probability, that at about the white heat, the affinity of the -combustible bodies for oxygene takes place in the following order. -Phosphorus, hydrogene, charcoal,<a id="FNanchor_179" href="#Footnote_179" class="fnanchor">[179]</a> -iron, sulphur, &c.</p> - -<p>This order of attraction is very different from that obtaining at the -red heat; in which temperature charcoal and iron have a much stronger -affinity for oxygene than either phosphorus or hydrogene.<a id="FNanchor_180" href="#Footnote_180" class="fnanchor">[180]</a></p> - -<p>The smallest quantity of oxygene given in the different analyses of -nitrous oxide just detailed, is thirty five hundred parts; the greatest -proportion is thirty-nine.</p> - -<p>Taking the mean estimations from the most accurate experiments, we may -<span class="pagenum" id="Page_325">[Pg 325]</span> -conclude that 100 grains of the known ponderable matter of nitrous -oxide, consist of about 36,7 oxygene, and 63,3 nitrogene; or taking -away decimals, of 37 oxygene to 63 nitrogene; which is identical with -the estimation given in <a href="#RES_I">Research I</a>.</p> - -<p id="RII_DII_15" class="f120 space-above1">XV. <i>Observations on -the combinations of<br /> Oxygene and Nitrogene.</i></p> - -<p>During the decompositions of the combinations of oxygene and nitrogene -by combustible bodies, a considerable momentary expansion of the acting -substances, and the bodies in contact with them is generally produced, -connected with increased temperature; whilst light is often generated -to a great extent.</p> - -<p>Of the causes of these phænomena we are at present ignorant. Our -knowledge of them must depend upon the discovery of the precise nature -of heat and light, and of the laws by which they are governed. The -application of general hypotheses to isolated facts can be of little -utility; for this reason I shall at present forbear to enter into any -<span class="pagenum" id="Page_326">[Pg 326]</span> -discussions concerning those agents, which are imperceptible to the -senses, and known only by solitary effects.</p> - -<p>Analysis and synthesis clearly prove that oxygene and nitrogene -constitute the known ponderable matter of atmospheric air, nitrous -oxide, nitrous gas, and nitric acid.</p> - -<p>That the oxygene and nitrogene of atmospheric air exist in chemical -union, appears almost demonstrable from the following evidences.</p> - -<p>1st. The equable diffusion of oxygene and nitrogene through every part -of the atmosphere, which can hardly be supposed to depend on any other -cause than an affinity between these principles.<a id="FNanchor_181" href="#Footnote_181" class="fnanchor">[181]</a></p> - -<p><span class="pagenum" id="Page_327">[Pg 327]</span> -2dly. The difference between the specific gravity of atmospheric -air, and a mixture of 27 parts oxygene and 73 nitrogene, as found by -calculation; a difference apparently owing to expansion in consequence -of combination.</p> - -<p>3dly. The conversion of nitrous oxide into nitrous acid, and a gas -analogous to common air, by ignition.</p> - -<p>4thly. The solubility of atmospheric air undecompounded in water.</p> - -<p><span class="smcap">Atmospheric Air</span>, then, may be considered as -the least intimate of the combinations of nitrogene and oxygene.</p> - -<p>It is an elastic fluid, permanent at all known temperatures, consisting -of,73 nitrogene, and,27 oxygene. It is decomposable at certain -temperatures, by most of the bodies possessing affinity for oxygene. It -is soluble in about thirty times its bulk of water, and as far as we -<span class="pagenum" id="Page_328">[Pg 328]</span> -are acquainted with its affinities, incapable of combining with most of -the simple and compound substances. 100 cubic inches of it weigh about -31 grains at 55° temperature, and 30 atmospheric pressure.</p> - -<p><span class="smcap">Nitrous Oxide</span> is a gas unalterable in its constitution, -at temperatures below ignition. It is composed of oxygene and nitrogene, -existing <i>perhaps</i> in the most intimate union which those -substances are capable of assuming.<a id="FNanchor_182" href="#Footnote_182" class="fnanchor">[182]</a> -Its properties approach to those of acids. It is decomposable by the -combustible bodies at very high temperatures, is soluble in double -its volume of water, and in half its bulk of most of the inflammable -fluids. It is combinable with the alkalies, and capable of forming -with them peculiar salts. 100 grains of it are composed of about 63 -nitrogene, and 37 oxygene. 100 cubic inches of it weigh 50 grains, at -55° temperature, and 30 atmospheric pressure. -<span class="pagenum" id="Page_329">[Pg 329]</span></p> - -<p><span class="smcap">Nitrous Gas</span> is composed of about,56 oxygene, and,44 -nitrogene, in intimate union. It is soluble in twelve times its bulk -of water, and is combinable with the acids, and certain metallic -solutions; it is possessed of no acid properties, and is decomposable -by most of the bodies that attract oxygene strongly, at high -temperatures. 100 cubic inches of it weigh about 34 grains, at the mean -temperature and pressure.</p> - -<p><span class="smcap">Nitric Acid</span> is a substance permanently aëriform at common -temperatures, composed of about 1 nitrogene, to 2,3 oxygene. It is -soluble to a great extent in water, and combinable with the alkalies, -and nitrous gas. It is decomposable by most of the combustible bodies, -at certain temperatures. 100 cubic inches of it weigh, at the mean -temperature and pressure, nearly 76 grains. -<span class="pagenum" id="Page_330">[Pg 330]</span></p> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_331">[Pg 331]</span></p> -<h2 id="RES_III" class="nobreak">RESEARCH III.</h2> -</div> - -<p class="f120">RELATING TO THE RESPIRATION OF NITROUS OXIDE, AND OTHER GASES.</p> - -<h3 id="RIII_DIV_I">DIVISION I.</h3> - -<p class="neg-indent"><i>EXPERIMENTS and OBSERVATIONS on the EFFECTS produced -upon ANIMALS by the RESPIRATION of NITROUS OXIDE.</i></p> -<p><span class="pagenum" id="Page_332">[Pg 332]</span></p> - -<p id="RIII_DI_01" class="f120">I. <i>Preliminaries.</i></p> - -<p class="drop-cap"><span class="smcap">The</span> term -<i>respirable</i>, in its physiological application, has been -differently employed. Some times by the respirability of a gas has been -meant, its power of supporting life for a great length of time, when -repeatedly applied to the blood in the lungs. At other times all gases -have been considered as respirable, which were capable of introduction -into the lungs by voluntary efforts, without any relation to their vitality.</p> -<p><span class="pagenum" id="Page_333">[Pg 333]</span></p> - -<p>In the last sense the word respirable is most properly employed. In -this sense it is used in the following sections. -<span class="pagenum" id="Page_334">[Pg 334]</span></p> - -<p>Non-respirable gases are those, which when applied to the external -organs of respiration, stimulate the muscles of the epiglottis in inch -a way as to keep it perfectly close on the glottis; thus preventing -the smallest particle of gas from entering into the bronchia, in spite -of voluntary exertions; such are carbonic acid, and acid gases in -general.<a id="FNanchor_183" href="#Footnote_183" class="fnanchor">[183]</a></p> - -<p>Of respirable gases, or those which are capable of being taken into the -lungs by voluntary efforts.</p> - -<p>One only has the power of uniformly supporting life;—atmospheric air. -Other gases, when respired, sooner or later produce death; but in -different modes.</p> - -<p>Some, as nitrogene and hydrogene, effect no positive change in the -<span class="pagenum" id="Page_335">[Pg 335]</span> -venous blood. Animals immersed in these gases die of a disease produced -by privation of atmospheric air, analogous to that occasioned by their -submersion in water, or non-respirable gases.</p> - -<p>Others, as the different varieties of hydrocarbonate, destroy life by -producing some positive change<a id="FNanchor_184" href="#Footnote_184" class="fnanchor">[184]</a> -in the blood, which probably immediately renders it incapable of -supplying the nervous and muscular fibres with principles essential to -sensibility and irritability.</p> - -<p>Oxygene, which is capable of being respired for a much greater length -of time than any other gas, except common air, finally destroys life; -first producing changes in the blood, connected with new living -action.<a id="FNanchor_185" href="#Footnote_185" class="fnanchor">[185]</a></p> - -<p>After experiments, to be detailed hereafter, made upon myself and -others, had proved that nitrous oxide was respirable, and capable of -<span class="pagenum" id="Page_336">[Pg 336]</span> -supporting life for a longer time than any of the gases, except -atmospheric air and oxygene, I was anxious to ascertain the effects of -it upon animals, in cases where its action could be carried to a full -extent; and to compare the changes occasioned by it in their organs, -with those produced by other powers.</p> - -<p id="RIII_DI_02" class="f120 space-above1">II. <i>On the respiration -of Nitrous Oxide<br /> by warm-blooded Animals.</i></p> - -<p>The nitrous oxide employed in the following experiments, was procured -from nitrate of ammoniac, and received in large jars, filled with water -previously saturated with the gas. The animal was introduced into the -jar, by being carried under the water; after its introduction, the jar -was made to rest on a shelf, about half an inch below the surface of -the water; and the animal carefully supported, so as to prevent his -mouth from resting in the water.</p> - -<p>This mode of experimenting, either under water or mercury, is -<span class="pagenum" id="Page_337">[Pg 337]</span> -absolutely necessary, to ascertain with accuracy the effects of -pure gases on living beings. In some experiments that I made on the -respiration of nitrous oxide, by animals that were plunged into jars -of it opened in the atmosphere, and immediately closed after their -introduction, the unknown quantities of common air carried in, were -always sufficient to render the results perfectly inaccurate.</p> - -<p>Animals suffer little or nothing by being passed through water.</p> - -<p>That the phænomena in these experiments might be more accurately -observed, two or three persons were always present at the time of their -execution, and an account of them was noted down immediately after.</p> - -<p><i>a.</i> A stout and healthy young cat, of four or five months old, -was introduced into a large jar of nitrous oxide. For ten or twelve -moments he remained perfectly quiet, and then began to make violent -motions, throwing himself round the jar in every direction. In two -minutes he appeared quite exhausted, and sunk quietly to the bottom of -<span class="pagenum" id="Page_338">[Pg 338]</span> -the jar. On applying my hand to the thorax, I found that the heart beat -with extreme violence; on feeling about the neck, I could distinctly -perceive a strong and quick pulsation of the carotids. In about three -minutes the animal revived, and panted very much; but still continued -to lie on his side. His inspirations then became longer and deeper, and -he sometimes uttered very feeble cries. In four minutes the pulsations -of the heart appeared quicker and feebler. His inspirations were at -long intervals, and very irregular; in five minutes the pulse was -hardly perceptible; he made no motions, and appeared wholly senseless. -After five minutes and quarter he was taken out, and exposed to the -atmosphere before a warm fire. In a few seconds he began to move, and -to take deep inspirations. In five minutes he attempted to rise on his -legs; but soon fell again, the extremities being slightly convulsed. -In eight or nine minutes he was able to walk, but his motions were -staggering and unequal, the right leg being convulsed, whilst the other -<span class="pagenum" id="Page_339">[Pg 339]</span> -was apparently stiff and immoveable; in about half an hour he was -almost completely recovered.</p> - -<p><i>b.</i> A healthy kitten, of about six weeks old, was introduced -into nitrous oxide. She very soon began to make violent exertions, -and in less than a minute fell to the bottom of the receiver, as if -apoplectic. At this moment, applying my hand to her side, I felt the -heart beating with great violence. She continued gasping, with long -inspirations, for three minutes and half; at the end of five minutes -and half she was taken out completely dead.</p> - -<p><i>c.</i> Another kitten of the same breed was introduced into nitrous -oxide, the day after. She exhibited the same phænomena, and died in it -in about five minutes and half.</p> - -<p><i>d.</i> A small dog that had accidentally met with a dislocation of -the vertebræ of the loins, and was in great pain, as manifested by his -moaning and whining, was introduced into a large jar of nitrous oxide. -He immediately became quiet, and lay on his side in the jar, breathing -very deeply. In four minutes his respiration became noisy, and his eyes -<span class="pagenum" id="Page_340">[Pg 340]</span> -sparkled very much. I was not able to apply my hand to the thorax. In -five minutes he appeared senseless, and in seven minutes was perfectly dead.</p> - -<p><i>e.</i> A strong rabbit, of ten or twelve months old, was introduced -into nitrous oxide. He immediately began to struggle very much, and in -a minute fell down senseless: in two minutes the legs became convulsed, -and his inspirations were deep and noisy: in less than five minutes he -appeared perfectly dead.</p> - -<p><i>f.</i> A rabbit of a month old introduced into nitrous oxide, became -senseless in less than a minute; the pulsations of the heart were very -strong at this moment: they gradually became weaker, and in three -minutes and half the animal was dead.</p> - -<p><i>g.</i> Another rabbit of the same breed, after being rendered -senseless in nitrous oxide in a minute and half, was taken out. He soon -became convulsed; in a minute began to breathe quickly; in two minutes -attempted to rise, but staggered, and fell again on his side. His hinder -<span class="pagenum" id="Page_341">[Pg 341]</span> -legs were paralytic for near five minutes. In twenty he had almost recovered.</p> - -<p><i>h.</i> A middle sized guinea-pig was much convulsed, after being in -nitrous oxide for a minute. In two minutes and half he was senseless. -Taken out at this period, he remained for some minutes by the side of -a warm fire, without moving; his fore legs then became convulsed; his -hind legs were perfectly paralytic. In this state he continued, without -attempting to rise or move, for near an hour, when he died.</p> - -<p><i>i.</i> A large and old guinea-pig died in nitrous oxide, exhibiting -the same phænomena as the other animals, in about five minutes and -quarter. A young one was killed in three minutes and half.</p> - -<p><i>j.</i> A small guinea-pig, after breathing nitrous oxide for a -minute and half, was taken out, and placed before a warm fire. He was -for a few minutes a little convulsed; but in a quarter of an hour got -quite well, and did not relapse.</p> - -<p><i>k.</i> A large mouse introduced into nitrous oxide, was for a few -<span class="pagenum" id="Page_342">[Pg 342]</span> -seconds very active. In half a minute he fell down senseless; in a -minute and quarter he appeared perfectly dead.</p> - -<p><i>l.</i> A mouse taken out of nitrous oxide, after being in it for -half a minute, continued convulsed for some minutes, but finally recovered.</p> - -<p><i>m.</i> A young hen was introduced into a vessel filled with nitrous -oxide. She immediately began to struggle very much; fell on her breast -in less than half a minute, and in two minutes was quite dead.</p> - -<p><i>n.</i> A goldfinch died in nitrous oxide in less than a minute.</p> - -<p>In each of these experiments a certain absorption of the gas was always -perceived, the water rising in the jar during the respiration of the -animal. From them we learn</p> - -<p>1st. That nitrous oxide is destructive when respired for a certain time -to the warm-blooded animals, apparently previously exciting them to a -great extent.</p> - -<p>2dly. That when its operation is stopped before compleat exhaustion is -brought on, the healthy living action is capable of being gradually -reproduced, by enabling the animal to respire atmospheric air. -<span class="pagenum" id="Page_343">[Pg 343]</span></p> - -<p>3dly. That exhaustion and death is produced in the small animals by -nitrous oxide sooner than in the larger ones, and in young animals of -the same species, in a shorter time than in old ones, as indeed Dr. -Beddoes had conjectured a priori would be the case.</p> - -<p>Most of the animals destroyed in these experiments were examined after -death; the appearances in their organs were peculiar. To prevent unnecessary -repetitions, an account of them will be given in the fourth section.</p> - -<p id="RIII_DI_03" class="f120 space-above1">III. <i>Effects of the respiration -of Nitrous Oxide upon animals,<br /> as compared with those produced by their -immersion<br /> in Hydrogene and Water.</i></p> - -<p>Before the following experiments were made, a number of circumstances -had convinced me that nitrous oxide acted on animals by producing some -positive change in their blood, connected with new living action of the -irritable and sensitive organs, and terminating in their death. -<span class="pagenum" id="Page_344">[Pg 344]</span></p> - -<p>To ascertain however, the difference between the effects of this gas -and those of hydrogene and non-respirable gases, I proceeded in the -following way.</p> - -<p><i>a.</i> Of two healthy rabbits of about two months old, of the same -breed, and nearly of the same size.</p> - -<p>One was introduced into nitrous oxide. In a half a minute, it had -fallen down apparently senseless. On applying my hand to the thorax, -the action of the heart appeared at first, very quick and strong, it -gradually became weaker, and in two minutes and half, the animal was -taken out quite dead.</p> - -<p>The other was introduced into a jar of pure hydrogene through water. -He immediately began to struggle very much, and in a quarter of a -minute fell on his side. On feeling the thorax, the pulsations of the -heart appeared very quick and feeble, they gradually diminished; his -breathing became momentarily shorter, and in rather more than three -quarters of a minute, he was taken out dead. Dr. Kinglake was present at -<span class="pagenum" id="Page_345">[Pg 345]</span> -this experiment, and afterwards dissected both of the animals.</p> - -<p><i>b.</i> Of two similar rabbits of the same breed, nearly three -months old. One was introduced into nitrous oxide, and after being -rendered senseless by the respiration of it for nearly a minute and -half, was exposed to the atmosphere, before a warm fire. He recovered -gradually, but was occasionally convulsed, and had a paralysis of one -of his hinder legs for some minutes: in an hour he was able to walk. -The other, after being immerged in hydrogene for near half a minute, -was restored to the atmosphere apparently inanimate. In less than a -minute he began to breathe, and to utter a feeble noise; in two minutes -was able to walk, and in less than three minutes appeared perfectly -recovered.</p> - -<p><i>c.</i> A kitten of about two months old, was introduced into a jar -of nitrous oxide, at the same time that another of the same breed was -plunged under a jar of water. They both struggled very much. The animal -<span class="pagenum" id="Page_346">[Pg 346]</span> -in the nitrous oxide fell senseless before that under water had ceased -to struggle, and to throw out air from its lungs. In two minutes and -three quarters, the animal under water was quite dead: it was taken -out and exposed to heat and air, but did not shew the slightest signs -of life. At the end of three minutes and half, the animal in nitrous -oxide began to gasp, breathing very slowly; at four minutes and three -quarters it was yet alive; at the end of five minutes and quarter it -appeared perfectly dead. It was taken out, and did not recover.</p> - -<p>From these experiments it was evident, that animals lived at least -twice as long in nitrous oxide as in hydrogene or water. Consequently -from this circumstance alone, there was every reason to suppose that -their death in nitrous oxide could not depend on the simple privation -of atmospheric air; but that it was owing to some peculiar changes -effected in the blood by the gas. -<span class="pagenum" id="Page_347">[Pg 347]</span></p> - -<p id="RIII_DI_04" class="f120 space-above1">IV. <i>Of the changes effected -in the Organisation of<br /> warm-blooded Animals, by the respiration<br /> -of Nitrous Oxide.</i></p> - -<p>The external appearance of animals that have been destroyed in nitrous -oxide, is very little different from that of those killed by privation -of atmospheric air. The fauces and tongue appear of a dark red, and the -eyes are dull, and a little protruded. Their internal organs, however, -exhibit a very peculiar change. The lungs are pale brown red, and -covered here and there with purple spots; the liver is of a very bright -red, and the muscular fibre in general dark. Both the auricles and -ventricles of the heart are filled with blood. The auricles contract -for minutes after the death of the animal. The blood in the left -ventricle, and the aorta, is of a tinge between purple and red, whilst -that in the right ventricle is of a dark color, rather more purple than -the venous blood. But these appearances, and their causes, will be -better understood after the following comparative observations are read. -<span class="pagenum" id="Page_348">[Pg 348]</span></p> - -<p><i>a.</i> Of two similar rabbits, about eight months old, one A, was -killed by exposure for near six minutes to nitrous oxide, the other, B, -was destroyed by a blow on the head.</p> - -<p>They were both opened as speedily as possible. The lungs of B were -pale, and uniform in their appearance; this organ in A was redder, and -every where marked with purple spots. The liver of A was of a dark and -bright red, that of B of a pale red brown. The diaphragm of B, when -cut, was strongly irritable; that of A rather darker, and scarce at all -contractile. All the cavities of the heart contracted for more than 50 -minutes in B. The auricles contracted for near 25 minutes with force -and velocity in A: but the ventricles were almost inactive. The vena -cava, and the right auricle, in A, were filled with blood, apparently a -shade darker than in B. The blood in the left auricle, and the aorta, -appeared in A of a purple, a shade brighter than that of the venous -blood. In the left auricle of B it was red.</p> - -<p>I opened the head of each, but not without injuring the brains, so that -<span class="pagenum" id="Page_349">[Pg 349]</span> -I was unable to make any accurate comparison. The color of the brain in -A appeared rather darker than in B.</p> - -<p><i>b.</i> Two rabbits, C and D, were destroyed, C by immersion in -nitrous oxide, D in hydrogene: they were both dissected by Dr. -Kinglake. The blood in the pulmonary vein and the left auricle of C was -of a different tinge, from that in D more inclined to purple red. The -membrane of the lungs in C was covered with purple spots, that of D was -pale and uniform in its appearance. The brain in C was rather darker -than in D; but there was no perceptible effusion of blood into the -ventricles either in D or C. The liver in C was of a brighter red than -in health, that in D rather paler.</p> - -<p><i>c.</i> In the last experiment, the comparative irritability of the -ventricles and auricles of the heart and the muscular fibre in the -two animals, had not been examined. That these circumstances might be -<span class="pagenum" id="Page_350">[Pg 350]</span> -noticed, two rabbits, E and F were killed; E under water in about a -minute, and F in nitrous oxide in three minutes. They were immediately -opened, and after a minute, the appearance of the heart, and organs of -respiration observed.</p> - -<p>Both the right and left ventricles of the heart in F contracted but -very feebly; the auricles regularly and quickly contracted; the aorta -appeared perfectly full of blood. In E, a feeble contraction of the -left sinus venosus and auricle was observed; the left ventricle did not -contract: the right contracted, but more slowly than in F. In a few -minutes, the contractions of the ventricles in F had ceased, whilst -the auricles contracted as strongly and quickly as before. The blood -in the pulmonary veins of F was rather of a redder purple than in E; -the difference of the blood in the vena cava was hardly perceptible, -perhaps it was a little more purple in F. The membranous substance of -the lungs in F was spotted with purple as from extravasated blood, -whilst that in E was pale. The brain in F was darker than in E. On -opening the ventricles no extravasation of blood was perceptible. The -<span class="pagenum" id="Page_351">[Pg 351]</span> -auricles of the heart in F contracted strongly for near twenty minutes, -and then gradually their motion became less frequent; in twenty-eight -minutes it had wholly ceased. The right auricle and ventricle in E, -occasionally contracted for half an hour. The livers of both animals -were similar when they were first opened, of a dark red; that of F -preserved its color for some time when exposed to the atmosphere; -whilst that of E almost immediately became paler under the same -circumstances.</p> - -<p>The peristaltic motion continued for nearly an equal time in both -animals.</p> - -<p><i>d.</i> The sternum of a young rabbit was removed so that the heart -and lungs could be perceived, and he was introduced into a vessel -filled with nitrous oxide; the blood in the pulmonary veins gradually -became more purple, and the heart appeared to beat quicker than before, -all the muscles contracting with great force. After he had been in -<span class="pagenum" id="Page_352">[Pg 352]</span> -about a minute, spots began to appear on the lungs, though the -contractions of the heart became quicker and weaker; in three minutes -and half he was quite dead; after death the ventricles contracted very -feebly, though the contractions of the auricles were as strong almost -after the end of five minutes as at first. This animal was passed -through water saturated with nitrous oxide; possibly this fluid had -some effect on his organs.</p> - -<p>Besides these animals, many others, as guinea-pigs, mice and birds, -were dissected after being destroyed in nitrous oxide; in all of them -the same general appearance was observed. Their muscular fibre almost -always appeared less irritable than that of animals destroyed, by -organic læsion of part of the nervous system, in the atmosphere. The -ventricles of the heart in general, contracted feebly and for a very -short time; whilst the auricles continued to act for a great length of -time. The lungs were dark in their appearance, and always suffused here -and there with purple; the blood in the pulmonary veins when slightly -<span class="pagenum" id="Page_353">[Pg 353]</span> -observed, appeared dark, like venous blood, but when minutely examined, -was evidently much more purple. The blood in the vena cava, was darker -than that in the pulmonary veins. The cerebrum was dark.</p> - -<p>In a late experiment, I thought I perceived a slight extravasation of -blood in one of the ventricles of the brain in a rabbit destroyed in -nitrous oxide; but as this appearance had not occurred in the animals -I had examined before, or in those dissected by Dr. Kinglake, and Mr. -King, Surgeon, I am inclined to refer it to an accidental cause. At my -request, Mr. Smith, Surgeon, examined the brain of a young rabbit that -had been killed in his presence in nitrous oxide; he was of opinion -that no effusion of blood into the ventricles had taken place.</p> - -<p>In comparing the external appearance of the crural nerves in two -rabbits that had been dissected by Dr. Kinglake, having been destroyed -one in hydrogene, the other in nitrous oxide, we could perceive no -perceptible difference. -<span class="pagenum" id="Page_354">[Pg 354]</span></p> - -<p>It deserves to be noticed, that whenever the gall bladder and the -urinary bladder have been examined in animals destroyed in nitrous -oxide, they have been always distended with fluid; which is hardly ever -the case in animals killed by privation of atmospheric air.</p> - -<p>In the infancy of my experiments on the action of nitrous oxide upon -animals, I thought that it rendered the venous blood less coagulable; -but this I now find to be a mistake. The blood from the pulmonary -veins of animals killed in nitrous oxide, does not sensibly differ in -this respect from the arterial blood of those destroyed in hydrogene, -and both become vermilion nearly in the same time when exposed to the -atmosphere.</p> - -<p>In describing the various shades of color of the blood in the preceding -observations on the different dissected animals, the poverty of the -language of color, has obliged me to adopt terms, which I fear will -hardly convey to the mind of the reader, distinct notions of the -differences observable by minute examination in the venous and arterial -<span class="pagenum" id="Page_355">[Pg 355]</span> -blood of animals that die of privation of atmospheric air, and of those -destroyed by the action of nitrous oxide. This difference can only be -observed in the vessels by means of a strong light; it may however be -easily noticed in the fluid blood by the introduction of it from the -arteries or veins at the moment of their incision, between two polished -surfaces of white glass,<a id="FNanchor_186" href="#Footnote_186" class="fnanchor">[186]</a> -so closely adapted to each other, as to prevent the blood from coming -in contact with the atmosphere.</p> - -<p>Having four or five times had an opportunity of bleeding people in -the arm for trifling complaints, I have always received the blood in -phials, filled with various gases, in a mode to be described hereafter. -Venous blood agitated in nitrous oxide, compared with similar blood in -common air, hydrogene, and nitrogene, was always darker and more purple -<span class="pagenum" id="Page_356">[Pg 356]</span> -than the first, and much brighter and more florid than the two last, -which were not different in their color from venous blood, received -between two surfaces of glass. It will be seen hereafter, that the -coagulum of venous blood is rendered more purple when exposed to -nitrous oxide, whilst the gas is absorbed; likewise that blood altered -by nitrous oxide, is capable of being again rendered vermilion, by -exposure to the air.</p> - -<p>The appearances noticed in the above mentioned experiments, in the -lungs of animals destroyed in nitrous oxide, are similar to those -observed by Dr. Beddoes, in animals that had been made to breathe -oxygene for a great length of time.</p> - -<p>There were many reasons for supposing that the large purple spots -in the lungs of animals destroyed in nitrous oxide, were owing to -extravasation of venous blood from the capillary vessels; their coats -being broken by the highly increased arterial action. To ascertain -<span class="pagenum" id="Page_357">[Pg 357]</span> -whether these phænomena existed at a period of the action of nitrous -oxide, when the animal was recoverable by exposure to the atmosphere.</p> - -<p>I introduced a rabbit of six months old, into a vessel of nitrous -oxide, and after a minute, when it had fallen down apparently -apoplectic, plunged him wholly under water; he immediately began to -struggle, and what surprised me very much, died in less than a minute -after submersion. On opening the thorax, the blood in the pulmonary -veins was nearly of the color of that in animals that have been simply -drowned. The lungs were here and there, marked with a few points; -but there were no large purple spots, as in animals that have been -wholly destroyed in nitrous oxide: the right side of the heart only -contracted. In this experiment, the excitement from the action of the -gas was probably carried to such an extent, as to produce indirect -debility. There are reasons for supposing, that animals after having -been excited to but a small extent by the respiration of nitrous oxide, -will live under water for a greater length of time, than animals -previously made to breathe common air. -<span class="pagenum" id="Page_358">[Pg 358]</span></p> - -<p id="RIII_DI_05" class="f120 space-above1">V. <i>Of the respiration of -mixtures of Nitrous Oxide,<br /> and other gases, by warm-blooded Animals.</i></p> - -<p><i>a.</i> A rabbit of near two months old, was introduced into a -mixture of equal parts hydrogene and nitrous oxide through water. He -immediately began to struggle; in a minute fell on his side; in three -minutes gasped, and made long inspirations; and in four minutes and -half, was dead. On dissection, he exhibited the same appearances as -animals destroyed in nitrous oxide.</p> - -<p><i>b.</i> A large and strong mouse was introduced into a mixture of -three parts hydrogene to one part nitrous oxide. He immediately began -to struggle very much, in half a minute, became convulsed, and in about -a minute, was quite dead.</p> - -<p><i>c.</i> Into a mixture of one oxygene, and three nitrous oxide, a -small guinea-pig was introduced. He immediately began to struggle, and -in two minutes reposed on his side, breathing very deeply. He made -<span class="pagenum" id="Page_359">[Pg 359]</span> -afterwards no violent muscular motion; but lived quietly for near -fourteen minutes: at the end of which time, his legs were much -convulsed. He was taken out, and recovered.</p> - -<p><i>d.</i> A mouse lived apparently without suffering, for near ten -minutes, in a mixture of 1 atmospheric air, and 3 nitrous oxide, at the -end of eleven minutes he began to struggle, and in thirteen minutes -became much convulsed.</p> - -<p><i>e.</i> A cat of three months old, lived for seventeen minutes, -in a very large quantity of a mixture of 1 atmospheric air, and 12 -nitrous oxide. On her first introduction she was very much agitated -and convulsed, in a minute and half she fell down as if apoplectic, -and continued breathing very deeply during the remainder of the time, -sometimes uttering very feeble cries. When taken out, she appeared -almost inanimate, but on being laid before the fire, gradually began to -breathe and move; being for some time, like most of the animals that -have recovered after breathing nitrous oxide, convulsed on one side, -and paralytic the other. -<span class="pagenum" id="Page_360">[Pg 360]</span></p> - -<p><i>f.</i> A goldfinch lived for near five minutes in a mixture of equal -parts nitrous oxide and oxygene, without apparently suffering. Taken -out, he appeared faint and languid, but finally recovered.<a id="FNanchor_187" href="#Footnote_187" class="fnanchor">[187]</a></p> - -<p id="RIII_DI_06" class="f120 space-above1">VI. <i>Recapitulation of -facts relating to<br /> the respiration of Nitrous Oxide,<br /> -by warm-blooded Animals.</i></p> - -<p>1. Warm-blooded animals die in nitrous oxide infinitely sooner than in -common air or oxygene; but not nearly in so short a time as in gases -incapable of effecting positive changes in the venous blood, or in -non-respirable gases.</p> - -<p>2. The larger animals live longer in nitrous oxide than the smaller -<span class="pagenum" id="Page_361">[Pg 361]</span> -ones, and young animals die in it sooner than old ones of the same species.</p> - -<p>3. When animals, after breathing nitrous oxide, are removed from it -before compleat exhaustion has taken place, they are capable of being -restored to health under the action of atmospheric air.</p> - -<p>4. Peculiar changes are effected in the organs of animals by the -respiration of nitrous oxide. In animals destroyed by it, the arterial -blood is purple red, the lungs are covered with purple spots, both the -hollow and compact muscles are <i>apparently</i> very inirritable, and -the brain is dark colored.</p> - -<p>5. Animals are destroyed by the respiration of mixtures of nitrous -oxide and hydrogene nearly in the same time as by pure nitrous oxide; -they are capable of living for a great length of time in nitrous oxide -mingled with very minute quantities of oxygene or common air.</p> - -<p>These facts will be reasoned upon in the next division. -<span class="pagenum" id="Page_362">[Pg 362]</span></p> - -<p id="RIII_DI_07" class="f120 space-above1">VII. <i>Of the -respiration of Nitrous Oxide<br /> by amphibious Animals.</i></p> - -<p>As from the foregoing experiments, it appeared that the nitrous oxide -destroyed warm-blooded animals by increasing the living action of -their organs to such an extent, as finally to exhaust their -irritability and sensibility; it was reasonable to conjecture that the -cold-blooded animals, possessed of voluntary power over respiration, -would so regulate the quantity of nitrous oxide applied to the blood -in their lungs as to bear its action for a great length of time. This -conjecture was put to the test of experiment; the following facts will -prove its error.</p> - -<p><i>a.</i> Of two middle sized water-lizards, one was introduced into -a small jar filled with nitrous oxide, over moist mercury, by being -passed through the mercury; the other was made to breathe hydrogene, by -being carried into it in the same manner.</p> - -<p>The lizard in nitrous oxide, in two or three minutes, began to make -<span class="pagenum" id="Page_363">[Pg 363]</span> -violent motions, appeared very uneasy, and rolled about the jar in -every direction, sometimes attempting to climb to the top of it. The -animal in hydrogene was all this time very quiet, and crawled about the -vessel without being apparently much affected. At the end of twelve -minutes, the lizard in nitrous oxide was lying on his back seemingly -dead; but on agitating the jar he moved a little; at the end of fifteen -minutes he did not move on agitation, and his paws were resting on his -belly. He was now taken out stiff and apparently lifeless, but after -being exposed to the atmosphere for three or four minutes, took an -inspiration, and moved his head a little; he then raised the end of his -tail, though the middle of it was still stiff and did not bend when -touched. His four legs remained close to his side, and were apparently -useless; but on pricking them with the point of a lancet, they became -convulsed. After being introduced into shallow water, he was able to -crawl in a quarter of an hour, though his motions were very irregular. -<span class="pagenum" id="Page_364">[Pg 364]</span> -In an hour he was quite well. The animal in hydrogene appeared to have -suffered very little in three quarters of an hour, and had raised -himself against the side of the jar. At the end of an hour he was taken -out, and very soon recovered.</p> - -<p><i>b.</i> Some hours after, the same lizards were again experimented -upon. That which had been inserted into hydrogene in the last -experiment, being now inserted into nitrous oxide.</p> - -<p>This lizard was apparently lifeless in fourteen minutes, having tumbled -and writhed himself very much during the first ten minutes. Taken out -after being in twenty-five minutes, he did not recover. The other -lizard lived in hydrogene for near an hour and quarter, taken out after -an hour and twenty minutes, he was dead.</p> - -<p>These animals were both opened, but the viscera of the nitrous oxide -lizard were so much injured by the knife, that no accurate comparison -of them with those of the other could be made, I thought that the lungs -appeared rather redder. -<span class="pagenum" id="Page_365">[Pg 365]</span></p> - -<p><i>c.</i> Of two similar large water-lizards, one was introduced into -a vessel standing over mercury, wholly filled with water that had been -long boiled and suffered to cool under mercury.</p> - -<p>The animal very often rose to the top of the jar as, if in search -of air, during the first half hour; but shewed no other signs of -uneasiness. At the end of three quarters of an hour, he became very -weak, and appeared scarcely able to swim in the water. Taken out at the -end of fifty minutes, he recovered.</p> - -<p>The other was inserted into nitrous oxide. After much struggling, -he became senseless in about fifteen minutes, and lay on his back. -Taken out at the end of twenty minutes, he remained for a long time -motionless and stiff, but in a quarter of an hour, began to move some -of his limbs.</p> - -<p>From these experiments, we may conclude, that water-lizards, and most -probably the other amphibious animals, die in nitrous oxide in a much -shorter time than in hydrogene or pure water; consequently their death -<span class="pagenum" id="Page_366">[Pg 366]</span> -in it cannot depend on the simple privation of atmospheric air.</p> - -<p>At the season of the year in which this investigation was carried on, I -was unable to procure frogs or toads. This I regret very much.</p> - -<p>Supposing that cold-blooded animals die in nitrous oxide from positive -changes effected in their blood by the gas, it would be extremely -interesting to notice the apparent alterations taking place in their -organs of respiration and circulation during its action, which -could easily be done, the membranous substance of their lungs being -transparent. The increase or diminution of the irritability of their -muscular fibre, might be determined by comparative galvanic experiments.</p> - -<p id="RIII_DI_08" class="f120 space-above1">VIII. <i>Effects of -solution of nitrous oxide<br /> in water on Fishes.</i></p> - -<p><i>a.</i> A small flounder was introduced into a vessel filled with -solution of nitrous oxide in water over mercury. He remained at rest -<span class="pagenum" id="Page_367">[Pg 367]</span> -for ten minutes and then began to move about the jar in different -directions. In a half an hour he was apparently dying, lying on his -side in the water. He was now taken out, and introduced into a vessel -filled with water saturated with common air, he very soon recovered.</p> - -<p><i>b.</i> Of two large thornbacks,<a id="FNanchor_188" href="#Footnote_188" class="fnanchor">[188]</a> -equally brisk and lively. One, A, was introduced into a jar containing -nearly 3 cubic inches of water, saturated with nitrous oxide, and which -previous to its impregnation had been long boiled; the other, B, was -introduced into an equal quantity of water which had been deprived of -air by distillation through mercury.</p> - -<p>A, appeared very quiet for two or three minutes, and then began to move -up and down in the jar, as if agitated. In eight minutes his motions -became very irregular, and he darted obliquely from one side of the jar -<span class="pagenum" id="Page_368">[Pg 368]</span> -to the other. In twelve minutes, he became still, and moved his gills -very slowly. In fifteen minutes he appeared dead. After sixteen minutes -he was taken out, but shewed no signs of life.</p> - -<p>B was very quiet for four minutes and half. He then began to move -about the jar. In seven minutes he had fallen on his back, but still -continued to move his gills. In eleven minutes he was motionless; taken -out after thirteen minutes, he did not recover.</p> - -<p><i>c.</i> Of two thornbacks, one, C was introduced into about an ounce -of boiled water in contact with hydrogene, standing over mercury. The -other, D, was introduced into well boiled water saturated with nitrous -oxide, and standing in contact with it over mercury. C lived near -thirteen minutes, and died without being previously much agitated. D -was apparently motionless, after having the same affections as A in the -last experiment, in sixteen minutes. At the end of this time he was -taken out and introduced into common water. He soon began to move his -<span class="pagenum" id="Page_369">[Pg 369]</span> -gills, and in less than a quarter of an hour was so far recovered as to -be able to swim.</p> - -<p>The last experiment was repeated on two smaller thornbacks; that in the -aqueous solution of nitrous oxide lived near seventeen minutes, that in -the water in contact with hydrogene, about fifteen and half.</p> - -<p>The experiments in <a href="#RI_DIV_III">Res. I. Div. 3</a>, prove -the difficulty, and indeed almost impossibility of driving from water -by boiling, the whole of the atmospheric air held in solution by it; -they likewise show that nitrous oxide by its strong affinity for water, -is capable of expelling air from that fluid after no more can be -procured from it by ebullition.</p> - -<p>Hence, if water saturated with nitrous oxide had no positive effects -upon fishes; they ought to die in it much sooner than in water deprived -of air by ebullition. From their living in it rather longer;<a id="FNanchor_189" href="#Footnote_189" class="fnanchor">[189]</a> -we may conclude, that they are destroyed not by privation of atmospheric -air, but from some positive change effected in their blood by the gas. -<span class="pagenum" id="Page_370">[Pg 370]</span></p> - -<p>A long while ago, from observing that the gills of fish became rather -of a lighter red during their death, in the atmosphere; I conjectured -that the disease of which they died, was probably hyperoxygenation -of the blood connected with highly increased animal heat. For not -only is oxygene presented to their blood in much larger quantities in -atmospheric air than in its aqueous solution; but likewise, to use -common language, in a state in which it contains much more <i>latent -heat</i>. Without however laying any stress on this supposition, I -had the curiosity to try whether thornbacks would live longest in -atmospheric air or nitrous oxide. In one experiment, they appeared to -die in them nearly in the same time. In another, the fish in nitrous -oxide lived nearly half as long again as that in atmospheric air.</p> - -<p id="RIII_DI_09" class="f120 space-above1">IX. <i>Effects of -Nitrous Oxide on Insects.</i></p> - -<p><span class="pagenum" id="Page_371">[Pg 371]</span> -The winged insects furnished with breathing holes, become motionless -in nitrous oxide very speedily; being however possessed of a certain -voluntary power over respiration, they sometimes recover, after having -been exposed to it for some minutes, under the action of atmospheric air.</p> - -<p>A butterfly was introduced into a small jar, filled with pure nitrous -oxide, over mercury, He struggled a little during the first two or -three seconds; in about seven seconds, his legs became convulsed, and -his wings were wrapt round his body; in about half a minute he was -senseless; taken out after six minutes, he did not recover.</p> - -<p>Another butterfly introduced into hydrogene, became convulsed in about -a quarter of a minute, was senseless in twenty seconds, and taken out -after five minutes, did not revive.</p> - -<p>A large drone, after being in nitrous oxide for a minute and a quarter, -was taken out senseless. After being for some time exposed to the -atmosphere, he began to move, and at last rose on his wings. For some -time, however, he was unable to fly in a straight line; and often after -<span class="pagenum" id="Page_372">[Pg 372]</span> -describing circles in the air, fell to the ground as if giddy.</p> - -<p>A large fly, became motionless in nitrous oxide after being convulsed, -in about half a minute. Another was rendered senseless in hydrogene, in -less than a quarter of a minute.</p> - -<p>A fly introduced into hydrocarbonate, dropt immediately senseless; -taken out after about a quarter of a minute, he recovered; but like the -fly that had lived after exposure to nitrous oxide, was for some time -vertiginous.</p> - -<p>Flies live much longer under water, alcohol, or oil, than in -non-respirable gases, or gases incapable of supporting life. A certain -quantity of air always continues attached in the fluid to the fine -hairs surrounding their breathing holes, sufficient to support life for -a short time.</p> - -<p>Snails and earth-worms, live in nitrous oxide a long while, they die in -it however, much sooner than in water or hydrogene; probably from the -same causes as the amphibious animals. -<span class="pagenum" id="Page_373">[Pg 373]</span></p> - -<h3 id="RIII_DIV_II">DIVISION II.</h3> - -<p class="neg-indent"><i>Of the CHANGES effected in NITROUS OXIDE, and other -GASES, by the RESPIRATION of ANIMALS.</i></p> - -<p id="RIII_DII_01" class="f120">I. <i>Preliminaries.</i></p> - -<p class="drop-cap"><span class="smcap">As</span> soon as I had -discovered that nitrous oxide was respirable, and possessed of -extraordinary powers of action on living beings, I was anxious to -be acquainted with the changes effected in it by the venous blood. -To investigate these changes, appeared at first a simple problem; I -soon however found that it involved much preliminary knowledge of -the chemical properties and affinities of nitrous oxide. After I had -<span class="pagenum" id="Page_374">[Pg 374]</span> -ascertained by experiments detailed in the preceding Researches, the -composition of this gas its combinations, and the physical changes -effected by it in living beings, I began my enquiry relating to the -mode of its operation.</p> - -<p>Finding that the residual gas of nitrous oxide after it had been -breathed for some time in silk bags, was chiefly nitrogene, I at first -conjectured that nitrous oxide was decomposed in respiration in the -same manner as atmospheric air, and its oxygene only combined with the -venous blood; the following experiments soon however convinced me of my -error.</p> - -<p id="RIII_DII_02" class="f120 space-above1">II. <i>Absorption of -Nitrous Oxide by venous blood.<br /> Changes effected in the blood -by different Gases.</i></p> - -<p><i>a.</i> Though the laws of the coagulability of the blood are -unknown, yet we are certain that at the moment of coagulation, a -perfectly new arrangement of its principles takes place; consequently, -their powers of combination must be newly modified. The affinities of -<span class="pagenum" id="Page_375">[Pg 375]</span> -living blood can only be ascertained during its circulation in the -vessels of animals. At the moment of effusion from those vessels, -it begins to pass through a series of changes, which first produce -coagulation, and finally its compleat decomposition.</p> - -<p>Consequently, the action of fluid blood upon gates out of the vessels, -will be more analogous to that of circulating blood in proportion as it -is more speedily placed in contact with them.</p> - -<p><i>b.</i> To ascertain the changes effected in nitrous oxide by fluid -venous blood.</p> - -<p>A jar, six inches long and half an inch wide, graduated to,05 -cubic inches, having a tight stopper adapted to it, was filled with -nitrogene, which is a gas incapable of combining with, and possessing -no power of a action upon venous blood. A large orifice was made in -the vein of a tolerably healthy man, and the stopper removed from the -jar, which was brought in contact with the arm so as to receive the -blood, and pressed close against the skin, in such a way as to leave an -<span class="pagenum" id="Page_376">[Pg 376]</span> -orifice just sufficient for the escape of the nitrogene, as the blood -flowed in. When the jar was full, it was closed, and carried to the -pneumatic apparatus, the mercury of which had been previously a little -warmed. A small quantity of the blood was transferred into another -jar to make room for the gas. The remaining quantity equalled exactly -two cubic inches; to this was introduced as speedily as possible, -eleven measures equal to,55 cubic inches of nitrous oxide, which -left a residuum of ¹/₃₂ only, when absorbed by boiled water, and was -consequently, perfectly pure. On agitation, a rapid diminution of the -gas took place.</p> - -<p>In the mass of blood which was opaque, but little change of color could -be perceived; but that portion of it diffused over the sides of the -jar, was evidently of a brighter purple than the venous blood.</p> - -<p>It was agitated for two or three minutes, and then suffered to rest; in -eight minutes it had wholly coagulated; a small quantity of serum had -separated, and was diffused over the coagulum. This coagulum was dark; -<span class="pagenum" id="Page_377">[Pg 377]</span> -but evidently of a more purple tinge than that of venous blood; no gas -had apparently been liberated during its formation.</p> - -<p>The nitrous oxide remaining, was not quite equal to seven measures; -hence, at least four measures of it had been absorbed.</p> - -<p>To ascertain the nature of the residuum, it was necessary to transfer -it into another vessel, but this I found very difficult to accomplish, -on account of the coagulated blood. By piercing through the coagulum -and removing part of it by means of curved iron forceps, I at last -contrived to introduce about 4½ measures of the gas into a small -cylinder, graduated to,25 cubic inches, in which it occupied of -course, nearly 9 measures; when a little solution of strontian was -admitted to these, it became very slightly clouded; but the absorption -that took place did not more than equal half its bulk. Consequently, -the quantity of carbonic acid evolved from the blood, or formed, must -have been extremely minute. -<span class="pagenum" id="Page_378">[Pg 378]</span></p> - -<p>On the introduction of pure water, a rapid absorption of the gas took -place, and after agitation, not quite 3 measures remained. These did -not <i>perceptibly</i> diminish with nitrous gas; their quantity was -too small to be examined by any other test; but there is reason to -suppose that they were chiefly composed of nitrogene.</p> - -<p>From this experiment, it appeared that nitrous oxide is absorbed when -placed in contact with venous blood; at the same time, that a very -minute quantity of carbonic acid and probably nitrogene is produced.</p> - -<p><i>c.</i> In another similar experiment when nearly half a cubic inch -of nitrous oxide was absorbed by about a cubic inch and three quarters -of fluid blood, the residual gas did not equal more than ⅛, the -quantity absorbed being taken as unity. This fact induced me to suppose -that the absorption of nitrous oxide by venous blood, was owing to a -simple solution of the gas in that fluid, analogous to its solution in -water or alcohol.</p> - -<p>To ascertain if nitrous oxide could be expelled from blood impregnated -<span class="pagenum" id="Page_379">[Pg 379]</span> -with it, by heat; I introduced to 2 cubic inches of fluid blood taken -from the medial vein, about,6 cubic inches of nitrous oxide. After -agitation, in seven minutes nearly,4 were absorbed. In ten minutes, -after the blood had completely coagulated, the cylinder containing it, -was transferred in contact with mercury, into a vessel of solution of -salt in water; this solution was heated and made to boil. During its -ebullition, the whole of the blood became either white or pale brown, -and formed a solid coherent mass; whilst small globules of gas were -given out from it. In a few minutes, about,25 of gas had collected. -After the vessel had cooled, I attempted to transfer this gas into -a small graduated jar in the mercurial apparatus, but in vain; the -mass in the jar was so solid and tough, that I could not remove it. -By transferring it to the water apparatus, I succeeded in displacing -enough of the coagulum to suffer the water to come in contact with -the gas; an absorption of nearly half of it took place; hence, -<i>I conjecture</i>, that nitrous oxide had been given out by the -impregnated blood. -<span class="pagenum" id="Page_380">[Pg 380]</span></p> - -<p><i>d</i>. Some fresh dark coagulum of venous blood, was exposed to -nitrous oxide. A very slight alteration of color took place at the -surface of the blood, perceptible only in a strong light, and a minute -quantity of gas was absorbed. A taper burnt in the remaining gas as -brilliantly as before, hence, it had apparently suffered no alteration.</p> - -<p><i>e</i>. To compare the physical changes effected in the venous -blood by nitrous oxide, with those produced by other gases, I made -the following experiments.—I filled a large phial, containing near -14 cubic inches, with blood from the vein of the arm of a man, and -immediately transferred it to the mercurial apparatus. Different -portions of it were thrown into small graduated cylinders, filled with -the following gases: nitrogene, nitrous gas, common air, oxygene, -nitrous oxide, carbonic acid, and hydrocarbonate.</p> - -<p>The blood in each of them was successively agitated till it began to -coagulate; and making allowances for the different periods of agitation, -<span class="pagenum" id="Page_381">[Pg 381]</span> -there was no marked difference in the times of coagulation.</p> - -<p>The color of the coagulum in every part of the cylinder, containing -nitrogene, was the same very dark red. When it was agitated so as to -tinge the sides of the jar, it appeared exactly of the color of venous -blood received between two surfaces of glass; no perceptible absorption -of the gas had taken place.</p> - -<p>The blood in nitrous gas was dark, and much more purple on the top than -that in nitrogene. When agitated so as to adhere to the jar as a thin -surface, this purple was evidently deep and bright. An absorption of -rather more than ⅛ of the volume of gas had taken place.</p> - -<p>The blood in oxygene and atmospheric air, were of a much brighter -tinge than that in any of the other gases. On the top, the color was -vermilion, but no perceptible absorption had taken place.</p> - -<p>The coagulum in nitrous oxide, when examined in the mass was dark, -and hardly distinguishable in its color from venous blood; but when -<span class="pagenum" id="Page_382">[Pg 382]</span> -minutely noticed at the surface where it was covered with serum, and in -its diffusion over the sides of the jar, it appeared of a fine purple -red, a tinge brighter than the blood in nitrous gas. An absorption had -taken place in this cylinder, more considerable than in any of the others.</p> - -<p>In carbonic acid, the coagulum was of a brown red, much darker than the -venous blood, and a slight diminution of gas had taken place.</p> - -<p>In the hydrocarbonate,<a id="FNanchor_190" href="#Footnote_190" class="fnanchor">[190]</a> -the blood was red, a shade darker than the oxygenated blood, and a very slight -diminution of the gas<a id="FNanchor_191" href="#Footnote_191" class="fnanchor">[191]</a> -was perceptible.</p> - -<p><i>f.</i> To human blood that had been saturated with nitrous oxide -whilst warm and constantly agitated for four or five minutes, to -prevent its uniform coagulation, oxygene was introduced; the red purple -<span class="pagenum" id="Page_383">[Pg 383]</span> -on the surface of it, immediately changed to vermilion; and on -agitation, this color was diffused through it. On comparing the tinge -with that of oxygenated blood, no perceptible difference could be -observed. No change of volume of the oxygene introduced, had taken -place; and consequently, no nitrous oxide had been evolved from the -blood.</p> - -<p><i>g.</i> Blood, impregnated with nitrous gas, was exposed to oxygene; -but after agitation in it for many minutes, no change of its dark -purple tinge could be observed, though a slight diminution of the -oxygene appeared to take place.</p> - -<p><i>h.</i> Blood that had been rendered vermilion in every part by long -agitation in atmospheric air, the coagulum of which was broken and -diffused with the coagulable lymph through the serum, was exposed to -nitrous oxide; for some minutes no perceptible change of color took -place; but by agitation for two or three hours, it evidently affirmed a -purple tinge, whilst a a slight absorption of gas took place. It never -<span class="pagenum" id="Page_384">[Pg 384]</span> -however, became nearly so dark as venous blood that had been exposed to -nitrous oxide.</p> - -<p><i>i.</i> Blood, oxygenated in the same manner as in the last -experiment, the coagulum of which had been broken, was exposed to -nitrous gas. The surface of it immediately became purple, and by -agitation for a few minutes, this color was diffused through it. A -slight diminution of the gas was observed. On comparing the tinge with -that of venous blood that had been previously exposed to nitrous gas, -there was no perceptible difference.</p> - -<p><i>k.</i> Blood exposed to oxygenated muriatic acid is wholly altered -in its constitution and physical properties, as has been often noticed; -the coagulum becomes black in some parts, and brown and white in -others. Venous blood, after agitation in hydrogene or nitrogene, -oxygenates when exposed to the atmosphere in the same manner as simple -venous blood. I had the curiosity to try whether venous blood exposed -to hydrogene, would retain its power of being oxygenated longer than -<span class="pagenum" id="Page_385">[Pg 385]</span> -blood saturated with nitrous oxide: for this purpose some similar black -coagulum was agitated for some time in two phials, one filled with -hydrogene, the other with nitrous oxide. They were then suffered to -rest for three days at a temperature from about 56° to 63°. After being -opened, no offensive smell was perceived in either of them, the blood -in hydrogene was rather darker than at the time of their exposure, -whilst that in nitrous oxide was of a brighter purple. On being -agitated for some time in the atmosphere, the blood in nitrous oxide -became red, but not of so bright a tinge as oxygenated venous blood. -The color of the blood in hydrogene did not at all alter.</p> - -<p><i>l.</i> To ascertain whether impregnation with nitrous oxide -accelerated or retarded the putrefaction of the blood; I exposed venous -blood in four phials, the first filled with hydrocarbonate, the second -with hydrogene; the third with atmospheric air, and the fourth with -nitrous oxide. Examined after a fortnight, the blood in hydrogene and -<span class="pagenum" id="Page_386">[Pg 386]</span> -common air were both black, and stunk very much; that in hydrocarbonate -was red, and perfectly sweet; that in nitrous oxide appeared purple and -had no disagreeable smell.</p> - -<p>In a second experiment, when blood was exposed for three weeks to -hydrocarbonate and nitrous oxide, that in nitrous oxide was darker than -before and stunk a little; that in hydrocarbonate was still perfectly -sweet. The power of hydrocarbonate to prevent the putrefaction of -animal matters, was long ago noticed by Mr. Watt.</p> - -<p><i>m.</i> Having accidentally cut one of my fingers so as to lay bare a -little muscular fibre, I introduced it whilst bleeding into a bottle of -nitrous oxide; the blood that trickled from the wound evidently became -much more purple; but the pain was neither alleviated or increased. -When however, the finger was taken out of the nitrous oxide and exposed -to the atmosphere, the wound smarted more than it had done before. -After it had ceased to bleed, I inserted it through water into a vessel -of nitrous gas; but it did not become more painful than before. -<span class="pagenum" id="Page_387">[Pg 387]</span></p> - -<p>From all these observations, we may conclude,</p> - -<div class="blockquot"> -<p>1st. That when nitrous oxide is agitated in fluid venous blood, a -certain portion of the gas is absorbed; whilst the color of the blood -changes from dark red to red purple.</p> - -<p>2dly. That during the absorption of nitrous oxide by the venous -blood, minute portions of nitrogene and carbonic acid are produced, -either by evolution from the blood, or from a decomposition of part of -the nitrous oxide.</p> - -<p>3dly. That venous blood impregnated with nitrous oxide is capable of -oxygenation; and vice versa; that oxygenated blood may be combined with -nitrous oxide.</p> -</div> - -<p>When blood separated into coagulum and serum, is exposed to nitrous -oxide, it is most probable that the gas is chiefly absorbed by the -serum. That nitrous oxide however is capable of acting upon the -coagulum, is evident from <i>d.</i> In the fluid blood, as we shall see -hereafter, nitrous oxide is absorbed by the attractions of the whole compound. -<span class="pagenum" id="Page_388">[Pg 388]</span></p> - -<p id="RIII_DII_03" class="f120 space-above1">III. <i>Of the changes effected -in Nitrous Oxide<br /> by Respiration.</i></p> - -<p>To ascertain whether the changes effected in nitrous oxide by the -circulating blood acting through the moist coats of the pulmonary -veins of living animals, were highly analogous to those produced in -it by fluid venous blood removed from the vessels, I found extremely -difficult.</p> - -<p>I have before observed, that when animals are made to respire nitrous -oxide, a certain absorption of the gas always takes place; but the -smaller animals, the only ones that can be experimented upon in the -mercurial apparatus, die in nitrous oxide so speedily and occasion so -slight a diminution of gas, that I judged it useless to attempt to -analise the residuum of their respiration, which supports flame as well -as pure nitrous oxide, and is chiefly absorbable by water.</p> - -<p>In the infancy of my researches, I often respired nitrous oxide in a -<span class="pagenum" id="Page_389">[Pg 389]</span> -large glass bell, furnished with a breathing tube and stop-cock, and -poised in water saturated with the gas.</p> - -<p>In two or three experiments in which the nostrils being closed after -the exhaustion of the lungs, the gas was inspired from the bell and -respired into it, a considerable diminution was perceived, and by the -test of lime water some carbonic acid appeared to have been formed; but -on account of the absorption of this carbonic acid by the impregnated -water, and the liberation of nitrous oxide from it, it was impossible -to determine with the least accuracy, the quantities of products after -respiration.</p> - -<p>About this time likewise, I often examined the residuum of nitrous -oxide, after it had been respired in silk bags. In these experiments -when the gas had been breathed for a long time, a considerable -diminution of it was observed, and the remainder extinguished flame and -gave a very slight diminution with nitrous gas. But the great quantity -of this remainder as well as other phænomena, convinced me that though -<span class="pagenum" id="Page_390">[Pg 390]</span> -the oiled silk was apparently air-tight when dry, under slight -pressure, yet during the action of respiration, the moist and warm gas -expired, penetrated through it, whilst common air entered through the -wetted surface.</p> - -<p>To ascertain accurately, the changes effected in nitrous oxide by -respiration, I was obliged to make use of the large mercurial airholder -mentioned in <a href="#RES_I">Research I</a>. of the capacity of 200 -cubic inches. The upper cylinder of it was accurately balanced so as -to be constantly under the pressure of the atmosphere. To an aperture -in it, a stop-cock having a very large orifice was adapted, curved -and flattened at its upper extremity, so as to form an air-tight -mouth-piece.</p> - -<p>By accurately closing the nose, and bringing the lips tight on the -mouth-piece, after a few trials I was able to breathe oxygene or common -air in this machine for two minutes or two minutes and half, without -any other uneasy feeling than that produced by the inclination of the -neck and chest towards the cylinder. The power of uniformly exhausting -<span class="pagenum" id="Page_391">[Pg 391]</span> -the lungs and fauces to the same extent, I did not acquire till after -many experiments. At last, by preserving exactly the same posture -after exhaustion of the lungs before the inspiration of the gas to be -experimented upon, and during its compleat expiration, I found that I -could always retain nearly the same quantity of gas in the bronchial -vessels and fauces; the difference in the volume expired at different -times, never amounting to a cubic inch and half.</p> - -<p>By connecting the conducting pipe of the mercurial airholder, during -the respiration of the gas, with a small trough of mercury by means of -a curved tube, it became a perfect and excellent breathing machine. -For by exerting a certain pressure on the airholding cylinder, it was -easy to throw a quantity of gas after every inspiration or expiration, -into tubes filled with mercury standing in the trough. In these tubes -it could be accurately analised, and thus the changes taking place at -different periods of the process ascertained.</p> - -<p>Whenever I breathed pure nitrous oxide in the mercurial airholder, -<span class="pagenum" id="Page_392">[Pg 392]</span> -after a compleat voluntary exhaustion of my lungs, the pleasurable -delirium was very rapidly produced, and being obliged to stoop on the -cylinder, the determination of blood to my head from the increased -arterial action in less than a minute became so great, as often to -deprive me of voluntary power over the muscles of the mouth. Hence, I -could never rely on the accuracy of any experiment, in which the gas -had been respired for more than three quarters of a minute.</p> - -<p>I was able to respire the gas with great accuracy for more than half -a minute; it at first, rather increasing than diminishing the power -of volition; but even in this short time, very strong sensations -were always produced, with sense of fulness about the head, somewhat -alarming; a feeling which hardly ever occurs to me when the gas is -breathed in the natural posture.</p> - -<p>In all the numerous experiments that I made on the respiration of -nitrous oxide in this way, a very considerable diminution of gas always -took place; and the diminution was generally apparently greater to the -eye during the first four or five inspirations. -<span class="pagenum" id="Page_393">[Pg 393]</span></p> - -<p>The residual gas of an experiment was always examined in the following -manner. After being transferred through mercury into a graduated -cylinder, a small quantity of concentrated solution of caustic potash -was introduced to it, and suffered to remain in contact with it for -some hours; the diminution was then noted, and the quantity of gas -absorbed by the potash, judged to be carbonic acid. To the remainder, -twice its bulk of pure water was admitted. After agitation and rest for -four or five hours, the absorption by this was noticed, and the gas -absorbed considered as nitrous oxide. The residual unabsorbable gas -was mingled over water with twice its bulk of nitrous gas; and by this -means, its composition, whether it consisted wholly of nitrogene, or of -nitrogene mingled with small quantities of oxygene, ascertained.</p> - -<p>From a number of experiments made at different times on the respiration -of nitrous oxide, I select the following as the most accurate. -<span class="pagenum" id="Page_394">[Pg 394]</span></p> - -<p>E. 1. At temperature 54°, I breathed 102 cubic inches of nitrous oxide, -which contained near ¹/₅₀ common air, for about half a minute, seven -inspirations and seven expirations being made. After every expiration, -an evident diminution of gas was perceived; and when the last full -expiration was made, it filled a space equal to 62 cubic inches.</p> - -<p>These 62 cubic inches analised, were found to consist of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Carbonic acid</td> - <td class="tdr_ws1">3,2</td> - </tr><tr> - <td class="tdl">Nitrous oxide<span class="ws2"> </span></td> - <td class="tdr_ws1">29,0</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">4,1</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1 bb">25,7</td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdr_ws1 bb2">62,0</td> - </tr><tr> - <td class="tdl"></td> - <td class="tdr_ws1"></td> - </tr> - </tbody> -</table> - -<p>Hence, accounting for the two cubic inches of common air previously -mingled with the nitrous oxide, 71 cubic inches had disappeared in this -experiment.</p> - -<p>In the last respirations, the quantity of gas was so much diminished, -as to prevent the full expansion of the lungs; and hence the apparent -<span class="pagenum" id="Page_395">[Pg 395]</span> -diminution was very much less after the first four inspirations.</p> - -<p>E. 2. At temperature 47°, I breathed 182 cubic inches of nitrous oxide, -mingled with 2½ cubic inches of atmospheric air, which previously -existed in the airholder, for near 40 seconds; having in this time -made 8 respirations. The diminution after the first full inspiration, -appeared to a by-stander nearly uniform. When the last compleat -expiration was made, the gas filled a space equal to 128 cubic inches, -the common temperature being restored. These 128 cubic inches analised, -were found to consist of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Carbonic acid</td> - <td class="tdr_ws1">5,25</td> - </tr><tr> - <td class="tdl">Nitrous oxide<span class="ws2"> </span></td> - <td class="tdr_ws1">88,75</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">5,00</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">29,00</td> - </tr> - </tbody> -</table> - -<p>Consequently, in this experiment, 93,25 cubic inches of nitrous oxide -had disappeared.</p> - -<p>In each of these experiments, the cylinder was covered with condensed -<span class="pagenum" id="Page_396">[Pg 396]</span> -watry vapor exactly in the same manner as if common air had been -breathed in it. It ought to be observed that, E. 1. was made in the -morning, four hours and half after a moderate breakfast; whereas, E. -2. was made but an hour and quarter after a plentiful dinner; at which -near three fourths of a pint of table-beer had been drank.</p> - -<p>From these experiments we learn, that nitrous oxide is rapidly absorbed -by the venous blood, through the moist coats of the pulmonary veins. -But as after a compleat voluntary exhaustion of the lungs, much -residual air must remain in the bronchial vessels and fauces, as -appears from their incapability of compleatly collapsing, it is evident -that the gas expired after every inspiration of nitrous oxide mast be -mingled with different quantities of the residual gas of the lungs;<a id="FNanchor_192" href="#Footnote_192" class="fnanchor">[192]</a> -whilst after a complete expiration, much of the unabsorbed nitrous -oxide must remain as residual gas in the lungs. Now when a complete -<span class="pagenum" id="Page_397">[Pg 397]</span> -expiration is made after the breathing of atmospheric air, it is -evident that the residual gas of the lungs consists of nitrogene,<a id="FNanchor_193" href="#Footnote_193" class="fnanchor">[193]</a> -mingled with small portions of oxygene and carbonic acid. And these are -the only products found after the respiration of nitrous oxide.</p> - -<p>To ascertain whether these products were partially produced, during -the process of respiration, as I was inclined to believe from the -experiments in the last section, or whether they were wholly the -residual gases of the lungs, I found extremely difficult.</p> - -<p>I at first thought of breathing nitrous oxide immediately after my -lungs had been filled with oxygene; and to compare the products -remaining after the full expiration, with those produced after a full -expiration of pure oxygene; but on the supposition that oxygene and -nitrous oxide, when applied together to the venous blood, must effect -<span class="pagenum" id="Page_398">[Pg 398]</span> -changes in it different from either of them separately, the idea was -relinquished.</p> - -<p>I attempted to inspire nitrous oxide, after having made two -inspirations and a complete expiration of hydrogene; but in this -experiment the effects of the hydrogene were so debilitating, and the -consequent stimulation by the nitrous oxide so great, as to deprive -me of sense. After the first three inspirations, I lost all power of -standing, and fell on my back, carrying in my lips the mouth-piece -separated from the cylinder, to the great alarm of Mr. Patrick Dwyer, -who was noting the periods of inspiration.</p> - -<p>Though experiments on successive inspirations of pure nitrous oxide -might go far to determine whether or no any nitrogene, carbonic acid -and oxygene were products of respiration, yet I distinctly saw that it -was impossible in this way to ascertain their quantities, supposing -them produced, unless I could first determine the capacity of my lungs; -and the different proportions of the gases remaining in the bronchial -<span class="pagenum" id="Page_399">[Pg 399]</span> -vessels after a compleat expiration, when atmospheric air had been -respired.</p> - -<p>In some experiments (that I made on the respiration of hydrogene, -with a view to determine whether carbonic acid was <i>produced</i> by -the combination of carbon loosely combined in the venous blood, with -the oxygene respired, or whether it was simply <i>given out</i> as -excrementitious by this blood) I found, without however being able to -solve the problem I had proposed to myself, that in the respiration of -pure hydrogene, little or no alteration of volume took place; and that -the residual gas was mingled with some nitrogene, and a little oxygene -and carbonic acid.</p> - -<p>From the comparison of these facts with those noticed in the last -section and in R. III. Div. I. there was every reason to suppose -that hydrogene was not absorbed or altered when respired: but only -mingled with the residual gases of the lungs. Hence, by making a full -expiration of atmospheric air, and afterwards taking six or seven -<span class="pagenum" id="Page_400">[Pg 400]</span> -respirations of hydrogene in the mercurial airholder, and then making -a compleat expiration, I conjectured that the residual gas and the -hydrogene would be so mingled, as that nearly the same proportions -should remain in the bronchial vessels, as in the airholder. By -ascertaining these proportions and calculating from them, I hoped to be -able to ascertain with tolerable exactness, the capacity of my fauces -and bronchia, as well as the composition of the gas remaining in them, -after a complete expiration of common air.</p> - -<p id="RIII_DII_04" class="f120 space-above1">IV. <i>Respiration -of Hydrogene.</i></p> - -<p>The hydrogene that I employed, was procured from the decomposition of -water by means of clean iron filings and diluted sulphuric and muriatic -acids. It was breathed in the same manner as nitrous oxide, in the -large mercurial airholder.</p> - -<p>After a compleat voluntary exhaustion of my lungs in the usual posture, -<span class="pagenum" id="Page_401">[Pg 401]</span> -I found great difficulty in breathing hydrogene for so long as half a -minute, so as to make a compleat expiration of it. It produced uneasy -feelings in the chest, momentary loss of muscular power, and sometimes -a transient giddiness.</p> - -<p>In some of the experiments that I made; on account of the giddiness, -the results were rendered inconclusive, by my removing my mouth from -the mouth-piece after expiration, before the assistant could turn the -stop-cock.</p> - -<p>The purity of the hydrogene was ascertained immediately before the -experiment by the test of nitrous gas, and by detonation with oxygene -or atmospheric air; generally 12 measures of atmospheric air were fired -with 4 of the hydrogene, and if the diminution was to ten or a little -more, the gas was judged to be pure.</p> - -<p>After the experiment, when the compleat expiration had been made and -the common temperature restored; the volume of the gas was noticed, -and then a small quantity of it thrown into the mercurial apparatus by -means of the conducting tube, to be examined. The carbonic acid was -<span class="pagenum" id="Page_402">[Pg 402]</span> -separated by from it by means of solution of potash or strontian; the -quantity of oxygene it contained, was ascertained by means of nitrous -gas of known composition; the superabundant nitrous gas was absorbed -by solution of muriate of iron; and the proportions of hydrogene -and nitrogene in the remaining gas, discovered by inflammation with -atmospheric air or oxygene in the detonating tube by the electric spark.</p> - -<p><i>a.</i> The two following experiments made upon quantities of -hydrogene, equal to those of the nitrous oxide respired in the -experiments in the last section, are given as the most accurate of five.</p> - -<p>E. 1. I respired at 59° 102 cubic inches of hydrogene apparently pure, -for rather less than half a minute, making in this time seven quick -respirations.</p> - -<p>After the complete expiration, when the common temperature was -restored, the gas occupied a space equal to 103 cubic inches nearly. -These analised were found to consist of -<span class="pagenum" id="Page_403">[Pg 403]</span></p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Carbonic acid</td> - <td class="tdr_ws1">4,0</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">3,7</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">17,3</td> - </tr><tr> - <td class="tdl">Hydrogene</td> - <td class="tdr_ws1 bb">78,0</td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdr_ws1">103,0</td> - </tr> - </tbody> -</table> - -<p>Now as in this experiment, the gas was increased in bulk only a cubic -inch; supposing that after the compleat expiration the gas in the -lungs, bronchia and fauces was of nearly similar composition with -that in the airholder, and that no hydrogene had been absorbed by the -blood, it would follow that 24 cubic inches of hydrogene remained in -the internal organs of respiration, and consequently, by the rule of -proportion, about 7,8 of the mixed residual gas of the common air. -And then the whole quantity of residual gas of the lungs, supposing -the temperature 59°, would have been 31,8 cubic inches; but as its -temperature was nearly that of the internal parts of the body, 98°, it -<span class="pagenum" id="Page_404">[Pg 404]</span> -must have filled a greater space; calculating from the experiments of -Guyton and Vernois,<a id="FNanchor_194" href="#Footnote_194" class="fnanchor">[194]</a> about 37,5<a id="FNanchor_195" href="#Footnote_195" class="fnanchor">[195]</a> -cubic inches.</p> - -<p>From the increase of volume, it would appear that a minute quantity -of gas had been generated during the respiration, and this was, as we -shall see hereafter, most probably carbonic acid.<a id="FNanchor_196" href="#Footnote_196" class="fnanchor">[196]</a> -Likewise there is reason to suppose, that a little of the residual oxygene must -have been absorbed. Making allowances for those circumstances, it would -follow, that the 37,5 cubic inches of gas remaining in my lungs, after -a compleat expiration of atmospheric air at animal heat 98°, equal to -31,8 cubic inches at 59°, were composed of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">21,9</td> - </tr><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">4,9</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1 bb">5,0</td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdr_ws1">31,8</td> - </tr> - </tbody> -</table> - -<p><span class="pagenum" id="Page_405">[Pg 405]</span> -E. 2. I respired for near a half a minute in the mercurial airholder at -61°, 182 cubic inches of hydrogene; having made during this time, six -long inspirations. After the last expiration, the gas filled a space -nearly equal to 184 cubic inches, and analised, was found to consist of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">4,8</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">4,6</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">21,0</td> - </tr><tr> - <td class="tdl">Hydrogene</td> - <td class="tdr_ws1 bb">153,6</td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdr_ws1">184,0</td> - </tr> - </tbody> -</table> - -<p>Now in this experiment, reasoning in the same manner as before, 28,4 -cubic inches of hydrogene must have remained in the lungs, and likewise -5,5 of the atmospheric residual gas. Consequently, the whole residual -gas was nearly equal to 34 cubic inches at 61°, which at 98° would -become about 40,4 cubic inches. And reasoning as before, it would -appear from this experiment, that the quantity of gas remaining in my -<span class="pagenum" id="Page_406">[Pg 406]</span> -lungs after a compleat voluntary respiration, equalled at 98, about 40 -cubic inches, and at 61°, 34 nearly: making the necessary corrections; -that after common air had been breathed, these 34 cubic inches -consisted of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">4,1</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">5,5</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">24,4</td> - </tr> - </tbody> -</table> - -<p><i>b.</i> It would have been possible to prove the truth of the -postulate on which the experiments were founded, by respiring common -air or oxygene after the compleat expiration of the hydrogene, for the -same time as the hydrogene was respired and in equal quantities.</p> - -<p>For if portions of hydrogene were found in the airholder equal to those -of the residual gases in the two experiments, it would prove that a -<i>uniform</i> mixture of residual gas with the gas inspired, was -produced by the respiration. That this mixture must have taken place, -appeared, however, so evident from analogous facts, that I judged the -experimental proof unnecessary.</p> - -<p>Indeed, as most gases, though of different specific gravities, when -<span class="pagenum" id="Page_407">[Pg 407]</span> -brought in contact with each other, assume some sort of union, it -is more than probable, that gas inspired into the lungs, from being -placed in contact with the residual gas on such an extensive surface, -must instantly mingle with it. Hence, possibly one deep inspiration -and compleat expiration of the whole of a quantity of hydrogene, will -be sufficient to determine the capacity of the lungs after compleat -voluntary exhaustion, and the nature of the residual air.</p> - -<p>That two inspirations are sufficient, appears probable from the -following experiment.</p> - -<p>E. 3. After a compleat voluntary expiration of common air, I made two -deep inspirations of 141 cubic inches of hydrogene. After the compleat -expiration, they filled a space equal to rather more than 142 cubic -inches, and analised, were found to consist of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">3,1</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">4,5</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">18,8</td> - </tr><tr> - <td class="tdl">Hydrogene</td> - <td class="tdr_ws1 bb">115,6</td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdr_ws1">142,0</td> - </tr> - </tbody> -</table> - -<p><span class="pagenum" id="Page_408">[Pg 408]</span> -Now calculating on the exhausted capacity of my lungs from this -experiment, supposing uniform mixture, they would contain after -expiration of common air, about 30,7 cubic inches at 58°, equal to 36 -at 98°, composed of about</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">20,9</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">5,8</td> - </tr><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1 bb">4,0</td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdr_ws1">30,7</td> - </tr> - </tbody> -</table> - -<p>One should suppose a priori that in this experiment much less of the -residual oxygene of the lungs must have been absorbed, than in Expts. 1 -and 2; yet there is no very marked difference in the portions evolved. -That a tolerably accurate mixture took place, appears from the quantity -of nitrogene. The smaller quantity of carbonic acid is an evidence in -favour of its evolution from the venous blood.</p> - -<p><i>c.</i> It is reasonable to suppose that the pressure upon the -residual gas of the exhausted lungs, must be nearly equal to that of -the atmosphere. But as aqueous vapour is perpetually given out by the -<span class="pagenum" id="Page_409">[Pg 409]</span> -exhalents, and perhaps evolved from the moist coats of the pulmonary -vessels, it is likely that the residual gas is not only fully saturated -with moisture at 98°, but likewise impregnated with uncombined vapor; -and hence its volume enlarged beyond the increment of expansion of -temperature.</p> - -<p>Considering all these circumstances, and calculating from the mean -of the three experiments on the composition of the residual gas, I -concluded,</p> - -<p>1st. That the exhausted capacity of my lungs was equal to about 41 -cubic inches.</p> - -<p>2dly. That the gas contained in my bronchial vessels and fauces, after -a compleat expiration of atmospheric air, was equal to about 32 cubic -inches, its temperature being reduced to 55°.</p> - -<p>3dly. That these 32 cubic inches were composed of about</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">23,0</td> - </tr><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">4,1</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">4,9</td> - </tr> - </tbody> -</table> - -<p><span class="pagenum" id="Page_410">[Pg 410]</span> -<i>d.</i> In many experiments made in the mercurial airholder on the -capacity of my lungs under different circumstances, I found that I -threw out of my lungs by a full forced expiration at temperatures from -58° to 62°</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl"> </td> - <td class="tdr_ws1"><b>cub. in.</b></td> - <td class="tdr_ws1"><b>cub. in.</b></td> - </tr><tr> - <td class="tdl">After a full voluntary inspiration, from<span class="ws2"> </span></td> - <td class="tdr_ws1">189 to</td> - <td class="tdr_ws1">191 </td> - </tr><tr> - <td class="tdl">After a natural inspiration, from</td> - <td class="tdr_ws1">78 to</td> - <td class="tdr_ws1">79 </td> - </tr><tr> - <td class="tdl">After a natural expiration, from</td> - <td class="tdr_ws1">67 to</td> - <td class="tdr_ws1">68 </td> - </tr> - </tbody> -</table> - -<p>So that making the corrections for temperature, it would appear, that -my lungs in a state of voluntary inspiration, contained about 254 -cubic inches; in a state of natural inspiration about 135; in a state -of natural expiration, about 118; and in a state of forced expiration -41.<a id="FNanchor_197" href="#Footnote_197" class="fnanchor">[197]</a></p> - -<p>As the exhausted capacity as well as impleted capacity of the internal -organs of respiration must be different in different individuals, -<span class="pagenum" id="Page_411">[Pg 411]</span> -according as the forms and size of their thorax, fauces, and bronchia -are different, it would be almost useless to endeavour to ascertain a -standard capacity. It is however probable, that a ratio exists between -the quantities of air inspired in the natural and forced inspiration, -those expired in the natural and forced expiration, and the whole -capacity of the lungs. If this ratio were ascertained, a single -experiment on the natural inspiration and expiration of common air, -would enable us to ascertain the quantity of residual gas in the lungs -of any individual after a compleat forced expiration.<a id="FNanchor_198" href="#Footnote_198" class="fnanchor">[198]</a></p> - -<p id="RIII_DII_05" class="f120 space-above1">V. <i>Additional observations -and experiments<br /> on the Respiration of Nitrous Oxide.</i></p> - -<p><i>a.</i> Having thus ascertained the capacity of my lungs, and the -composition of the residual gas of expiration, I proceeded to reason -<span class="pagenum" id="Page_412">[Pg 412]</span> -concerning the experiments in section III, on the respiration of -nitrous oxide.</p> - -<p>In Exp. I. nearly 100 cubic inches of nitrous oxide, making the -corrections on account of the common air, were respired for half a -minute. In this time, they were reduced to 62 cubic inches, which -consisted of 3,2 carbonic acid, 29 nitrous oxide, 4,1 oxygene, and 25,7 -nitrogene.</p> - -<p>But, as appears from the last section, there existed in the lungs -before the inspiration of the nitrous oxide, about 32 cubic inches of -gas, consisting of 23 nitrogene, 4,1 carbonic acid, and 4,9 oxygene, -temperature being reduced to 59°. This gas must have been perfectly -mingled with the nitrous oxide during the experiment; and consequently, -the residual gas in the lungs after the experiment, was of the same -composition as that in the airholder.</p> - -<p>Supposing it as before, to be about 32 cubic inches: from the rule -of proportion, they will be composed of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Nitrous oxide</td> - <td class="tdr_ws1">14,7</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">13,3</td> - </tr><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">1,9</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">2,1</td> - </tr> - </tbody> -</table> - -<p><span class="pagenum" id="Page_413">[Pg 413]</span> -And the whole quantity of gas in the lungs and the airholder, supposing -the temperature 59°, will equal 94 cubic inches, which are composed of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Nitrous oxide</td> - <td class="tdr_ws1">43,7</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">39,0</td> - </tr><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">5,2</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1 bb">6,1</td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdr_ws1">94  </td> - </tr> - </tbody> -</table> - -<p>But before the experiment, the gas in the lungs and airholder equalled -134 cubic inches, and these, reckoning for the common air, were -composed of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Nitrous oxide</td> - <td class="tdr_ws1">100  </td> - </tr><tr> - <td class="tdl">Nitrogene,</td> - <td class="tdr_ws1">24,3</td> - </tr><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">4,1</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">5,6</td> - </tr> - </tbody> -</table> - -<p>Hence, it appears, that 56,3 cubic inches of nitrous oxide were -absorbed in this experiment, and 13,7 of nitrogene produced, either by -<span class="pagenum" id="Page_414">[Pg 414]</span> -evolution from the blood, or decomposition of the nitrous oxide. The -quantities of carbonic acid and oxygene approach so near to those -existing after the respiration of hydrogene, that there is every reason -to believe that no portion of them was produced in consequence of the -absorption, or decomposition of the nitrous oxide.</p> - -<p><i>b.</i> In Exp. 2, calculating in the same manner, before the first -inspiration, a quantity of gas equal to 216,5 cubic inches at 47°, -existed in the lungs and airholder, and these 216,5 cubic inches were -composed of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Nitrous oxide,</td> - <td class="tdr_ws1">182,0</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">24,9</td> - </tr><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">4,1</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1 bb">5,5</td> - </tr><tr> - <td class="tdl"> </td> - <td class="tdr_ws1">216,5</td> - </tr> - </tbody> -</table> - -<p>After the compleat expiration, 160 cubic inches remained in the lungs -and airholder, which was composed of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Nitrous oxide</td> - <td class="tdr_ws1">110,6</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">36,3</td> - </tr><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">6,8</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">6,3</td> - </tr> - </tbody> -</table> - -<p><span class="pagenum" id="Page_415">[Pg 415]</span> -Hence, it appears, that 71,4 cubic inches of nitrous oxide were -absorbed in this experiment, and about 12 of nitrogene produced. The -quantity of carbonic acid and oxygene is rather greater than that which -existed in the experiments on hydrogene.</p> - -<p><i>c.</i> From these estimations, I learned that a small quantity -of nitrogene was produced during the absorption of nitrous oxide in -respiration. It remained to determine, whether this nitrogene owed its -production to evolution from the blood, or to the decomposition of a -portion of the nitrous oxide.</p> - -<p>Analogical evidences were not in favour of the hypothesis of -decomposition. It was difficult to suppose that a body requiring the -temperature of ignition for its decomposition by the most inflammable -bodies, should be partially absorbed and partially decompounded at 98°, -by a fluid apparently possessed of uniform attractions.</p> - -<p>It was more easy to believe, that from the immense quantity of -nitrogene taken into the blood in nitrous oxide; the system soon became -<span class="pagenum" id="Page_416">[Pg 416]</span> -overcharged with this principle, which not being wholly expended in new -combinations during living action, was liberated in the aëriform state -by the exhalents, or through the moist coats of the veins.</p> - -<p>Now if the last rationale were true, it would follow, that the -quantity of nitrogene produced in respiration, ought to be increased -in proportion as a greater quantity of nitrous oxide entered into -combination with the blood.</p> - -<p><i>d.</i> To ascertain whether this was the case, I made after full -voluntary exhaustion of my lungs, one full voluntary inspiration and -expiration of 108 cubic inches of nitrous oxide. After this, it filled -a space nearly equal to 99 cubic inches. The quantities of carbonic -acid and oxygene in these were not determined; but by the test of -absorption by water, they appeared to contain only 18 nitrogene; which -is very little more than should have been given from the residual gas -of the lungs.</p> - -<p>In a second experiment, I made two respirations of 108 cubic inches of -<span class="pagenum" id="Page_417">[Pg 417]</span> -nitrous oxide nearly pure. The diminution was to 95. On analysing -these 95, I found to my great surprise, that they contained only 17 -nitrogene. Hence, I could not but suspect some source of error in the -process.</p> - -<p>I now introduced into a strong new silk bag, the sides of which were -in perfect contact, about 8 quarts of nitrous oxide. From the mode of -introduction, this nitrous oxide must have been mingled with a little -common air, not however sufficient to disturb the results.</p> - -<p>I then adapted a cork cemented to a long curved tube to my right -nostril; the tube was made to communicate with the water apparatus; and -the left nostril being accurately closed, and the mouth-piece of the -silk bag tightly adapted to the lips, I made a full expiration of the -common air of my lungs, inspired nitrous oxide from the bag, and by -carefully closing the mouth-piece with my tongue, expired it through -the curved tube into the water apparatus. In this way, I made nine -respirations of nitrous oxide. The expired gas of the first respiration -<span class="pagenum" id="Page_418">[Pg 418]</span> -was not preserved; but part of the gas of the second, third, fifth, -seventh and ninth, were caught in seperate graduated cylinders. The -second, analised by absorption, consisted of about 29 absorbable gas, -which must have been chiefly nitrous oxide; and 17 unabsorbable gas, -which must have been chiefly nitrogene; and the third of 22 absorbable -gas, and 8 unabsorbable. The fifth was composed of 27 to 6; the seventh -of 23 to 7, and the ninth of 26 to 11.</p> - -<p><i>e.</i> Though the results of these experiments were not so -conclusive as could be wished; yet, comparing them with those of the -experiments in section III. it seemed reasonable to conclude, that -the production of nitrogene was increased, in proportion as the blood -became more fully impregnated with nitrous oxide.</p> - -<p>From this conclusion, compared with the phænomenon noticed in section -2, and in Div. I. section 4, I am induced to believe that the -production of nitrogene during the respiration of nitrous oxide, is not -owing to the decomposition of part of the nitrous oxide, in the aëriform -<span class="pagenum" id="Page_419">[Pg 419]</span> -state <i>immediately</i> by the attraction of the red particles of -venous blood for its oxygene; but that it is rather owing to a new -arrangement produced in the principles of the impregnated blood, during -circulation; from which, becoming supersaturated with nitrogene, it -gives it out through the moist coats of the vessels.</p> - -<p>For if any portion of nitrous oxide were decomposed immediately by the -red particles of the blood, one should conjecture, that the quantity of -nitrogene produced, ought to be greater during the first inspirations, -before these particles became fully combined with condensed oxygene. -If on the contrary, the whole of the nitrogene and oxygene of the -nitrous oxide were both combined with the blood, and carried through -the pulmonary veins and left chamber of the heart to the arteries; -then, supposing the oxygene chiefly expended in living action, whilst -the nitrogene was only partially consumed in new combinations, it would -follow, that the venous blood of animals made to breathe nitrous oxide, -<span class="pagenum" id="Page_420">[Pg 420]</span> -hyper-saturated with nitrogene, must be different from common venous -blood; and this we have reason to believe from the phænomena in Div. I. -section 4, is actually the case.</p> - -<p><i>f.</i> Besides the nitrogene generated during the respiration -of nitrous oxide, we have noticed the evolution of other products, -carbonic acid,<a id="FNanchor_199" href="#Footnote_199" class="fnanchor">[199]</a> -and water.</p> - -<p>Now as nearly equal quantities of carbonic acid are produced, whether -hydrogene or nitrous oxide is respired, provided the process is carried -on for the same time; there is every reason to believe, as we have said -before, that no part of the carbonic acid produced, is generated from the -immediate decomposition of nitrous oxide by carbon existing in the blood.</p> - -<p>Consequently, in these experiments, it must be either evolved from the -venous blood; or formed, by the slow combination of the oxygene of the -residual air of respiration with the charcoal of the blood. -<span class="pagenum" id="Page_421">[Pg 421]</span></p> - -<p>But if it was produced by the decomposition of residual atmospheric -air, it would follow, that its volume must be much less than that of -the oxygene of the residual air, which had disappeared; for some of -this oxygene must have been <i>absorbed</i> by the blood, and during -the conversion of oxygene into carbonic acid by charcoal, a slight -diminution of volume is produced.</p> - -<p>In the experiments when nitrous oxide and hydrogene were respired for -about half a minute, the medium quantity of carbonic acid produced, was -5,6 cubic inches nearly.</p> - -<p>Now we will assume, that the quantity of carbonic acid produced, is -in the ratio of the oxygene diminished; and there is every reason to -believe, that in the expiration of atmospheric air, the expired air and -the residual air are nearly of the same composition.</p> - -<p>Hence, no more carbonic acid can remain in the lungs or be produced -from the residual gas after the compleat expiration of common air, than -<span class="pagenum" id="Page_422">[Pg 422]</span> -that which can be generated from a volume of atmospheric air equal to -the residual gas of the lungs.</p> - -<p>The residual gas of the lungs, after compleat expiration, equals at -55°, 32 cubic inches, and 32 cubic inches of common air contain 8.6 -cubic inches of oxygene.</p> - -<p>But in the experiments on the respiration of hydrogene, not only -5.6 cubic inches of carbonic acid were produced, but more than 4 of -residual oxygene remained unabsorbed.</p> - -<p>Hence it appears impossible that all the carbonic acid evolved from the -lungs during the respiration of nitrous oxide or hydrogene could have -been produced by the combination of charcoal in the venous blood with -residual atmospheric oxygene: there is consequently every reason to -believe that it is wholly or partially liberated from the venous blood -through the moist coats of the vessels.</p> - -<p><i>g.</i> The water carried out of the lungs in solution by the expired -gas of nitrous oxide, could neither have been wholly or partially -<span class="pagenum" id="Page_423">[Pg 423]</span> -formed by the decomposition of nitrous oxide. The coats of the vessels -in the lungs, and indeed in the whole internal surface of the body, are -always covered with moisture, and the solution of part of this moisture -by the inspired heated gas, and its deposition by the expired gas, are -sufficient causes for the appearance of the phænomenon.</p> - -<p>There are no reasons for supposing that any of the residual atmospheric -oxygene is immediately combined with fixed or nascent hydrogene, or -hydrocarbonate, in the venous blood at 98°, by slow combustion, and -consequently none for supposing that water is immediately formed in -respiration.</p> - -<p>The evolution of water from the vessels in the lungs, is almost certain -from numerous analogies.</p> - -<p><i>h.</i> As from the experiments in section II. it appeared that -nitrous oxide was capable of being combined with oxygenated blood, -and vice versa, blood impregnated with nitrous oxide capable of -oxygenation; I was curious to ascertain what changes would be effected -<span class="pagenum" id="Page_424">[Pg 424]</span> -in nitrous oxide when it was respired, mingled with atmospheric air or -oxygene. For this purpose, without making a very delicate experiment, -I breathed in the large mercurial airholder about 112 cubic inches of -nitrous oxide, mingled with 44 of common air, for near half a minute, -in the usual mode. The gas, after expiration, filled a space nearly -equal to 119. I did not exactly ascertain the composition of the -residual gas; it supported flame rather better than common air, and -after the nitrous oxide was absorbed, gave much less diminution with -nitrous gas than atmospheric air.</p> - -<p><i>i.</i> I breathed a mixture of four quarts of nitrous oxide with -three quarts of hydrogene, in a dry silk bag, for near a minute; -an evident diminution was produced; but on account of the mode of -experimenting it was impossible to determine the quantity of nitrous -oxide absorbed, or the exact nature of the products. When a taper was -introduced into a little of the residual gas, it inflamed with a very -<span class="pagenum" id="Page_425">[Pg 425]</span> -feeble explosion. Now a mixture of 4 parts nitrous oxide and 3 -hydrogene, detonates when inflamed with very great violence.</p> - -<p><i>k.</i> Nitrous oxide can be respired without danger by the human -animal for a much longer time than that required for the death of the -smaller quadrupeds in it.</p> - -<p>I have breathed it two or three times in a considerable state of -purity, in a dry silk bag, for four minutes and quarter and four -minutes and half: some diseased individuals have respired it for -upwards of five minutes.</p> - -<p>In the infancy of my experiments, from general appearances, I thought -that the proportion of nitrous oxide absorbed in respiration was -greater in the first inspirations than the last; but this I have since -found to be a mistake. In the last respirations the apparent absorption -is indeed less; but this is on account of the increased evolution of -nitrogene from the blood. When nitrous oxide is respired for a long -time, the last inspirations are always fuller and quicker than the -first; but the consumption by the same individual is nearly in the -<span class="pagenum" id="Page_426">[Pg 426]</span> -ratio of the time of respiration. Three quarts, i. e. about 174 cubic -inches, are consumed so as to be unfit for respiration, by an healthy -individual with lungs of moderate capacity, in about a minute and -quarter; six quarts, or 348 cubic inches, last generally for two -minutes and half or two minutes and three quarters; eight quarts, or -464 cubic inches, for more than three minutes and half; and twelve, or -696 cubic inches, for nearly five.</p> - -<p>The quantities of nitrous oxide absorbed by the same individual, will, -as there is every reason to suppose, be different under different -circumstances, and will probably be governed in some measure by the -state of the health. It is reasonable to suppose, that the velocity of -the circulation must have a considerable influence on the absorption -of nitrous oxide; probably in proportion as it is greater a larger -quantity of gas will be consumed in equal times.</p> - -<p>I am inclined from two or three experiments, to believe that nitrous -oxide is absorbed more rapidly after hearty meals or during stimulation -<span class="pagenum" id="Page_427">[Pg 427]</span> -from wine or spirits, than at other times. As its absorption appears to -depend on a simple solution in the venous blood; probably diminution of -temperature will increase its capability of being absorbed.</p> - -<p><i>l.</i> The quantities of nitrous oxide absorbed by different -individuals, will probably be governed in some measure by the size -of their lungs and the surface of the blood vessels, all other -circumstances being the same.</p> - -<p>From the observations that I have been able to make on the absorption -of nitrous oxide, as compared with the capacity of the lungs, the range -of the consumption of different individuals does not extend to more -than a pint, or 30 cubic inches at the maximum dose.</p> - -<p>We may therefore conclude, that the medium consumption of nitrous oxide -by the respiration of different individuals, is not far from two cubic -inches, or about a grain every second, or 120 cubic inches, or 60 -grains every minute.</p> - -<p><i>m.</i> When nitrous oxide is breathed in tight silk bags, towards -the end of the experiment as the internal surface becomes moist, as I -<span class="pagenum" id="Page_428">[Pg 428]</span> -have before mentioned, a certain quantity of common air penetrates -through it and becomes mixed with the residual gas of the experiment; -but this quantity is always too small to destroy any of the effects of -the nitrous oxide. The residual gas of the common air, the nitrogene -and carbonic acid produced in the process, and the residuum of the -admitted atmospheric air, hardly ever amount after the experiment, -to one half of the volume of the nitrous oxide absorbed. There is -consequently, a perfect propriety in successively inspiring and -expiring the whole of a given quantity of nitrous oxide, till it is -nearly consumed. In the respiration of nitrous oxide as the gas is -absorbed and not decomposed, little will be gained in effect, by -perpetually inspiring and expiring new portions, whilst an immense -quantity of gas will be idly wasted, and this circumstance, considering -the expence of the substance, is of importance. -<span class="pagenum" id="Page_429">[Pg 429]</span></p> - -<p id="RIII_DII_06" class="f120 space-above1">VI. <i>On the respiration -of Atmospheric Air.</i></p> - -<p>Having thus ascertained the absorption of nitrous oxide in respiration, -and the evolution of nitrogene and carbonic acid from the lungs during -its absorption: considering atmospheric air as a compound in which -principles identical with those in nitrous oxide existed, though in -different quantities and looser combination, I was anxious to compare -the changes effected in this gas by respiration, with those produced in -nitrous oxide and oxygene; particularly as they are connected with the -health and life of animals.</p> - -<p>The ingenious experiments of Lavoisier and Goodwyn, prove the -consumption of oxygene in respiration, and the production of carbonic -acid. From many experiments on the respiration of common air, Dr. -Priestly suspected that a certain portion of nitrogene, as well as -oxygene, was absorbed by the venous blood. -<span class="pagenum" id="Page_430">[Pg 430]</span></p> - -<p><i>b.</i> In the following experiments on the respiration of -atmospheric air in the mercurial airholder; the composition of the -gas before inspiration and after expiration, was ascertained in the -following manner.</p> - -<p>Forty measures of it were agitated over mercury in solution of caustic -potash, and suffered to remain in contact with it for two or three -hours. The diminution was noted, and the gas absorbed judged to be -carbonic acid. Twenty measures of the gas, freed from carbonic acid, -were mingled with thirty of nitrous gas, in a tube of,5 inches -diameter; they were not agitated,<a id="FNanchor_200" href="#Footnote_200" class="fnanchor">[200]</a> -but suffered to rest for an hour or an hour and half, when the volume -occupied by them was noticed: and 50-<i>m</i> the volume occupied, -divided by 3 considered as the oxygene <i>x</i>, and 20-<i>x</i> -considered as the nitrogene.</p> - -<p><span class="pagenum" id="Page_431">[Pg 431]</span> -<i>c.</i> To ascertain the changes effected in atmospheric air by -single inspirations,</p> - -<p>I made, after a compleat voluntary exhaustion of my lungs, at -temperature 61°, one inspiration and expiration of 141 cubic inches of -atmospheric air. After expiration, they filled a space equal to 139 -cubic inches nearly. These 139 cubic inches analised were found to -consist of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">101</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">32</td> - </tr><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">6</td> - </tr> - </tbody> -</table> - -<p>The 141 cubic inches before inspiration, were composed of 103 -nitrogene, 1 carbonic acid and 37 oxygene. The time taken to perform -the inspiration and full expiration, was nearly a quarter of a minute.</p> - -<p>I repeated this experiment seven or eight times, and the quantity of -oxygene absorbed was generally from 5 to 6 cubic inches, the carbonic -acid formed from 5 to 5,5, and the quantity of nitrogene apparently -diminished by from 1 to 3 cubic inches. -<span class="pagenum" id="Page_432">[Pg 432]</span></p> - -<p>E. 2. I made, after a voluntary expiration of common air, one -inspiration and full expiration of 100 cubic inches of atmospheric air. -It was diminished nearly to 98¾ or 99 cubic inches, and analised, was -found to consist of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">71,7</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">22,5</td> - </tr><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">4,5</td> - </tr> - </tbody> -</table> - -<p>This experiment I likewise repeated four or five times, with very -little difference of result, and there always seemed to be a small -diminution of nitrogene. I made no corrections on account of the -residual air of the lungs in these processes, because there was every -reason to suppose that it was always of similar composition.</p> - -<p><i>c.</i> Before I could ascertain whether similar changes were -effected in atmospheric air, by natural inspirations as by forced ones, -I was obliged to practise respiration in the mercurial airholder, by -differing the conducting tube to communicate with the atmosphere till I -had attained the power of breathing in it naturally, without labor or -<span class="pagenum" id="Page_433">[Pg 433]</span> -attention; I then found by a number of experiments, that I took into my -lungs at every natural inspiration, about 13 cubic inches of air, and -that I threw out of my lungs at every expiration,<a id="FNanchor_201" href="#Footnote_201" class="fnanchor">[201]</a> -rather less than this quantity; about 12¾ cubic inches.</p> - -<p>The mean composition of the 13 cubic inches of air inspired, was</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl"> </td> - <td class="tdr_ws1"><b>cub. in.</b></td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">9,5</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">3,4</td> - </tr><tr> - <td class="tdl">Carbonic acid</td> - <td class="tdr_ws1">0,1</td> - </tr> - </tbody> -</table> - -<p>That of the 12,7 of air expired</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">9,3</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">2,2</td> - </tr><tr> - <td class="tdl">Carbonic acid<span class="ws2"> </span></td> - <td class="tdr_ws1">1,2</td> - </tr> - </tbody> -</table> - -<p>These results I gained from more than 20 experiments, so that I could -not possibly entertain any doubt of this accuracy.</p> - -<p>I found, by making a person observe my respirations when I was -<span class="pagenum" id="Page_434">[Pg 434]</span> -inattentive to the process, that I made about 26 or 27 natural -inspirations in a minute. So that calculating from the above -estimations, it would follow, that 31,6 cubic inches of oxygene were -consumed, and 5,2 inches of nitrogene lost in respiration every minute, -whilst 26,6 cubic inches of carbonic acid were produced.</p> - -<p>To collect the products of a great number of natural expirations so -as to ascertain whether their composition corresponded with the above -accounts, I proceeded in the following manner.</p> - -<p>I fastened my lips tight on the mouth-piece of the exhausted airholder, -and suffering my nostrils to remain open, inspired naturally through -them, throwing the expired air through my mouth into the airholder.</p> - -<p>In many experiments, I found that in about a half a minute, I made in -this way 14 or 15 expirations. The mean quantity of air collected was -171 cubic inches, and consisted of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl"> </td> - <td class="tdr_ws1"><b>cub. in.</b></td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">128</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">29</td> - </tr><tr> - <td class="tdl">Carbonic acid</td> - <td class="tdr_ws1">14</td> - </tr> - </tbody> -</table> - -<p><span class="pagenum" id="Page_435">[Pg 435]</span> -Comparing these results with the former ones, we find the mean -quantities of air respired in equal terms rather less; but the -proportions of carbonic acid, nitrogene and oxygene in the respired -air, nearly identical.</p> - -<p><i>e.</i> To ascertain the changes effected in a given quantity of -atmospheric air by continued respirations, I breathed after a compleat -expiration, at temperature 63°, 161 cubic inches of air for near a -minute, making in this time, 19 deep inspirations. After the compleat -expiration, which was very carefully made, the gas filled a space -nearly equal to 152 cubic inches, so that 9 cubic inches of gas had -disappeared.</p> - -<p>The 152 cubic inches analised, were found to consist of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl"> </td> - <td class="tdr_ws1"><b>cub. in.</b></td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">111,6</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">23, </td> - </tr><tr> - <td class="tdl">Carbonic acid,</td> - <td class="tdr_ws1">17,4</td> - </tr> - </tbody> -</table> - -<p>The 161 cubic inches before inspiration, were composed of</p> - -<p><span class="pagenum" id="Page_436">[Pg 436]</span></p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl"> </td> - <td class="tdr_ws1"><b>cub. in.</b></td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">117,0</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">42,4</td> - </tr><tr> - <td class="tdl">Carbonic acid</td> - <td class="tdr_ws1">1,6</td> - </tr> - </tbody> -</table> - -<p>But the residual gas in the lungs before the experiment, was of -different composition from that remaining in the lungs after the -experiment. Making corrections on account of this circumstance, as in -section IV. it appears that about 5,1 of nitrogene were absorbed in -respiration, 23,9 of oxygene consumed, and 12 of carbonic acid produced.</p> - -<p>I repeated this experiment three times; in each experiment the -diminution after respiration, was nearly the same; and the residual -gas making the necessary allowances, of similar composition. So that -supposing the existence of no source of error in the experiments from -which the quantity and composition of the residual gas of the lungs -were estimated in section IV. the absorption of nitrogene by the venous -blood, appears almost demonstrated. -<span class="pagenum" id="Page_437">[Pg 437]</span></p> - -<p><i>f.</i> To compare the changes effected in atmospheric air by -respiration of the smaller quadrupeds, with those in the experiments -just detailed, I introduced into a jar of the capacity of 20 cubic -inches filled with mercury in the mercurial trough, 15 cubic inches of -atmospheric air which had been deprived of its carbonic acid by long -exposure, to solution of potash.</p> - -<p>Temperature being 64°, a healthy small mouse was quickly passed under -the mercury into the jar, and suffered to rest on a very thin bit of -cheese, which was admitted immediately after.</p> - -<p>He continued for near 40 minutes without apparently suffering, -occasionally raising himself on his hind legs. At the end of 50 -minutes, he was lying on his side, and in 55 minutes was apparently -dying. He was now carefully taken out through the mercury by the tail, -and exposed before the fire, where he soon recovered. After the cheese -had been carefully removed, the gas in the jar filled a space nearly -<span class="pagenum" id="Page_438">[Pg 438]</span> -equal to 14 cubic inches; so that a diminution of a cubic inch had -taken place. These 14 cubic inches analised, were found to consist of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl"> </td> - <td class="tdr_ws1"><b>cub. in.</b></td> - </tr><tr> - <td class="tdl">Carbonic acid </td> - <td class="tdr_ws1">2,0</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">1,4</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">10,6</td> - </tr> - </tbody> -</table> - -<p>The 15 cubic inches before the experiment, consisted of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl"> </td> - <td class="tdr_ws1"><b>cub. in.</b></td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">4</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">11</td> - </tr> - </tbody> -</table> - -<p>Hence it appeared, that 2,6 cubic inches of oxygene had been consumed, -2 cubic inches of carbonic acid produced, and about 0,4 of nitrogene lost.</p> - -<p>The relation between the quantities of oxygene consumed in this -experiment, and the carbonic acid produced, are nearly the same as -that of those in the experiments just detailed; but the quantity of -nitrogene lost is much smaller. -<span class="pagenum" id="Page_439">[Pg 439]</span></p> - -<p id="RIII_DII_07" class="f120 space-above1">VII. <i>Respiration of Oxygene.</i></p> - -<p>The gases before and after respiration, were analised in these -experiments in the manner described in the last section, except that 3 -of nitrous gas were always employed to one of oxygene.</p> - -<p>E. I. At temperature 53°, after a full forced respiration, I respired -in the mercurial airholder, for half a minute, 102 cubic inches of -oxygene, making seven very long and deep inspirations. After the -compleat expiration, the gases filled a space equal to 93 cubic inches; -these 93 cubic inches analised, were found to consist of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl"> </td> - <td class="tdr_ws1"><b>cub. in.</b></td> - </tr><tr> - <td class="tdl">Carbonic acid </td> - <td class="tdr_ws1">5,9</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">33,8</td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">53,3</td> - </tr> - </tbody> -</table> - -<p>The 102 cubic inches before the experiment, were composed of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl"> </td> - <td class="tdr_ws1"><b>cub. in.</b></td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">78</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">24</td> - </tr> - </tbody> -</table> - -<p><span class="pagenum" id="Page_440">[Pg 440]</span> -The residual gas in the lungs before the experiment, was 32 cubic -inches, and composed of about 23 nitrogene, 4,1 carbonic acid, and 4,9 -oxygene, <a href="#RIII_DII_04">Section IV</a>. The residual gas after -expiration, was composed of 18,2 oxygene, 2 carbonic acid, and 11,8 nitrogene.</p> - -<p>Hence the whole of the gas in the lungs and airholder before -inspiration, was 134 cubic inches, composed of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl"> </td> - <td class="tdr_ws1"><b>cub. in.</b></td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">82,9</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">47,0</td> - </tr><tr> - <td class="tdl">Carbonic acid </td> - <td class="tdr_ws1">4,1</td> - </tr> - </tbody> -</table> - -<p>And after respiration, 125 cubic inches, consisting of</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl"> </td> - <td class="tdr_ws1"><b>cub. in.</b></td> - </tr><tr> - <td class="tdl">Oxygene</td> - <td class="tdr_ws1">71,5</td> - </tr><tr> - <td class="tdl">Nitrogene</td> - <td class="tdr_ws1">45,6</td> - </tr><tr> - <td class="tdl">Carbonic acid </td> - <td class="tdr_ws1">7,9</td> - </tr> - </tbody> -</table> - -<p>So that comparing the quantities, it appears, that 11,4 of oxygene and -1,4 of nitrogene, were consumed in this experiment, and 3,8 of carbonic -acid produced. -<span class="pagenum" id="Page_441">[Pg 441]</span></p> - -<p>I was much surprised at the small quantity of oxygene that had been -consumed in this experiment. This quantity was less than that expended -during the respiration of atmospheric air for half a minute: the -portion of carbonic acid evolved was likewise smaller. I could detect -no source of inaccuracy, and it was difficult to suppose that the -greater depth and fulness of the inspirations could make any difference.</p> - -<p>E. 2. I now respired at the same temperature, after a full expiration, -162 cubic inches of gas, composed of 133 oxygene and 20 nitrogene for -two minutes, imitating as much as possible, the natural respiration. -After the experiment, they filled a space equal to 123 cubic inches. -And when the analysis and calculations had been made as in the last -experiment, it appeared that 57 cubic inches of oxygene, and 2 of -nitrogene had been absorbed, whilst 21 cubic inches of carbonic acid -had been formed. -<span class="pagenum" id="Page_442">[Pg 442]</span></p> - -<p>Now from the estimations in the last section, it appears that 63 cubic -inches of oxygene are consumed, and about 52 cubic inches of carbonic -acid produced every two minutes during the natural respiration of -common air. So that supposing the experiment accurate, 6 cubic inches -of oxygene less are absorbed, and 30 cubic inches less of carbonic acid -produced every minute, when oxygene nearly pure is respired, than when -atmospheric air is respired.</p> - -<p>Both these experiments were made in the morning, at a time when I was -in perfect health; so that there could be apparently no source of error -from accidental circumstances.</p> - -<p>The uncommon and unexpected nature of the results, made me however, -very sceptical concerning them; and before I would draw any inferences, -I resolved to ascertain the comparative consumption of atmospheric air -and oxygene by the smaller quadrupeds, for which purpose, I made the -following experiment.</p> - -<p>E. 3. Of two strong and healthy small mice, apparently of the same -breed, and exactly similar. -<span class="pagenum" id="Page_443">[Pg 443]</span></p> - -<p>One was introduced into a jar containing 10 cubic inches and half of -oxygene, and 3 cubic inches of nitrogene, and made to rest on a bit of -cheese.</p> - -<p>The other was introduced into a jar containing fifteen cubic inches and -half of atmospheric air, and made to rest in the same manner on cheese.</p> - -<p>The mouse in oxygene began apparently to suffer in about half an hour, -and occasionally panted very much; in about an hour he lay down on his -side as if dying. The jars were often agitated, that the gases might be -well mingled.</p> - -<p>The mouse in atmospheric air became very feeble in 40 minutes, and at -the end of 50 minutes was taken out through the mercury alive, but -unable to stand.</p> - -<p>The mouse in oxygene was taken out in the same manner after an hour and -quarter, alive, but motionless, and breathing very deeply.</p> - -<p>The gas in the jars was examined. That in the oxygene jar filled a -<span class="pagenum" id="Page_444">[Pg 444]</span> -space exactly equal to 12,7 cubic inches, and analised, was found to -consist of 1,7 carbonic acid, 2,6 of nitrogene, and 8,4 of oxygene. So -that absolutely, 2,1 cubic inches of oxygene and,4 of nitrogene had -been consumed, and 1,7 of carbonic acid produced.</p> - -<p>The gas in the atmospheric air jar was diminished nearly to 14,4, -and consisted of 2,1 carbonic acid, 1,4 oxygene; and 10,9 nitrogene. -So that 2,7 of oxygene and,5 of nitrogene, had been consumed by the -mouse; and 2,1 of carbonic acid produced.</p> - -<p>Hence it appears, that the mouse in atmospheric air consumed nearly -one third more oxygene and produced nearly one fourth more carbonic -acid in respiration in 55 minutes, than the other in an hour and -quarter in oxygene. And if we consider the perpetual diminution of the -oxygene of the atmospheric air; from which at last it became almost -incapable of supporting the life of the animal; we may conclude, that -<span class="pagenum" id="Page_445">[Pg 445]</span> -the quantity of oxygene consumed by it, had the air been perpetually -renovated, would have been much more considerable.</p> - -<p>I design very shortly, to repeat these experiments, and to make others -on the comparative consumption of oxygene and atmospheric air, by the -larger quadrupeds. Whatever may be the results, I hope to be able to -ascertain from them, why pure oxygene is incapable of supporting life.</p> - -<p id="RIII_DII_08" class="f120">VIII. <i>Observations on the changes effected -in the blood, by<br /> atmospheric air and oxygene.</i></p> - -<p>From the experiments of Mr. Cigna and Dr. Priestley,<a id="FNanchor_202" href="#Footnote_202" class="fnanchor">[202]</a> -it appears that the coagulum of the venous blood becomes florid at its -surface when exposed to the atmosphere, though covered and defended -from the immediate contact of air by a very thick stratum of serum. -<span class="pagenum" id="Page_446">[Pg 446]</span></p> - -<p>Hence it is evident, that serum is capable of dissolving either the -whole compound atmospheric air, or the oxygene of it.</p> - -<p>Supposing what indeed is most probable from numerous analogies, that it -dissolves the whole compound; it would follow, that the coloring of the -coagulum of blood under serum, depended upon the decomposition of the -atmospheric air condensed in the serum, the oxygene<a id="FNanchor_203" href="#Footnote_203" class="fnanchor">[203]</a> -of it combining with the red particles, and the nitrogene either -remaining dissolved in the fluid, or being liberated through it into -the atmosphere.</p> - -<p>Now the circulating blood consists of red particles, floating in and -diffused through serum and coagulable lymph. -<span class="pagenum" id="Page_447">[Pg 447]</span></p> - -<p>In natural respiration, the red particles are rendered of a brighter -tinge during the passage of the blood through the pulmonary veins. And -as we have seen in the last sections, during respiration atmospheric -air is decomposed; all the oxygene of it consumed, <i>apparently</i> -a small portion of the nitrogene lost, and a considerable quantity of -carbonic acid produced.</p> - -<p>It seems therefore reasonable to suppose, that the whole compound -atmospheric air passing through the moist coats of the vessels is first -dissolved by the serum of the venous blood, and in its condensed state, -decomposed by the affinity of the red particles for its oxygene; the -greater part of the nitrogene being liberated unaltered; but a minute -portion of it possibly remaining condensed in the serum and coagulable -lymph, and passing with them into the left chamber of the heart.</p> - -<p>From the experiments on the respiration of nitrous oxide and hydrogene, -it appears that a certain portion of the carbonic acid produced in -<span class="pagenum" id="Page_448">[Pg 448]</span> -respiration, is evolved from the venous blood; but as a much greater -quantity is generated during the respiration of common air and oxygene, -than during that of hydrogene in equal times, it is not impossible but -that some portion of it may be formed by the combination of charcoal in -the red particles with the oxygene dissolved in the serum; but this can -only be determined by farther experiments.</p> - -<p>Supposing that no part of the water evolved in solution by the expired -gas of common air is formed immediately in respiration, it will follow -that a very considerable quantity of oxygene must be constantly -<i>combined</i> with the red particles, even allowing the consumption -of a certain portion of it to form carbonic acid; for the carbonic acid -evolved, rarely amounts to more than three fourths of the volume of the -oxygene consumed.</p> - -<p>Perhaps the serum of the blood is capable of dissolving a larger -quantity of atmospheric air than of pure oxygene. On this supposition, -it would be easy to explain the smaller consumption of oxygene in the -experiments in the last section. -<span class="pagenum" id="Page_449">[Pg 449]</span></p> - -<p id="RIII_DII_09" class="f120 space-above1">IX. <i>Observations on -the respiration<br />of Nitrous Oxide.</i></p> - -<p>The experiments in the <a href="#RIII_DIV_I">first Division</a> -of this Research, prove that nitrous oxide when respired by animals, -produces peculiar changes in their blood and in their organs, first -connected with increased living action; but terminating in death.</p> - -<p>From the experiments in this Division, it appears, that nitrous oxide -is rapidly absorbed by the circulating venous blood, and of course its -condensed oxygene and nitrogene distributed in the blood over the whole -of the system.</p> - -<p>Concerning the changes effected in the principles of the impregnated -blood during circulation and its action upon the nervous and muscular -fibre; it is useless to reason in the present state of our knowledge.</p> - -<p>It would be easy to form theories referring the action of blood -impregnated with nitrous oxide, to its power of supplying the nervous -<span class="pagenum" id="Page_450">[Pg 450]</span> -and muscular fibre with such proportions of condensed nitrogene, -oxygene and light or etherial fluid, as enabled them more rapidly -to pass through those changes which constitute their life: but such -theories would be only collections of terms derived from known -phænomena and applied by loose analogies of language to unknown things.</p> - -<p>We are unacquainted with the composition of dead organised matter; and -new instruments of experiment and new modes of research must be found, -before we can ascertain even our capabilities of discovering the laws -of life. -<span class="pagenum" id="Page_451">[Pg 451]</span></p> - -<hr class="chap x-ebookmaker-drop" /> -<p> <span class="pagenum" id="Page_452">[Pg 452]</span></p> - -<div class="chapter"> -<p><span class="pagenum" id="Page_453">[Pg 453]</span></p> -<h2 id="RES_IV" class="nobreak">RESEARCH IV.</h2> -</div> - -<p class="f120">RELATING TO THE EFFECTS PRODUCED BY<br /> THE RESPIRATION OF NITROUS OXIDE.</p> - -<h3 id="RIV_DIV_I">DIVISION I.</h3> - -<p class="neg-indent space-below1"><i>HISTORY of the DISCOVERY.—Effects -produced by the RESPIRATION of different GASES.</i></p> - -<p class="drop-cap"><span class="smcap">A short</span> time after I began the study of Chemistry, -in March 1798, my attention was directed to the dephlogisticated nitrous gas of -Priestley, by Dr. Mitchill’s Theory of Contagion.<a id="FNanchor_204" href="#Footnote_204" class="fnanchor">[204]</a></p> - -<p>The fallacy of this Theory was soon demonstrated, by a few coarse -experiments made on small quantities of the gas procured from zinc and -<span class="pagenum" id="Page_454">[Pg 454]</span> -diluted nitrous acid. Wounds were exposed to its action, the bodies of -animals were immersed in it without injury; and I breathed it mingled -in small quantities with common air, without remarkable effects. An -inability to procure it in sufficient quantities, prevented me at -this time, from pursuing the experiments to any greater extent. I -communicated an account of them to Dr. Beddoes.</p> - -<p>In 1799, my situation in the Medical Pneumatic Institution, made it my -duty to investigate the physiological effects of the aëriform fluids, -the properties of which presented a chance of useful agency. At this -period I recommenced the investigation.</p> - -<p>A considerable time elapsed before I was able to procure the gas in a -state of purity, and my first experiments were made on the mixtures of -nitrous oxide, nitrogene and nitrous gas, which are produced during -metallic solutions.</p> - -<p>In the beginning of March, I prepared a large quantity of impure -nitrous oxide from the nitrous solution of zinc. Of this I often -<span class="pagenum" id="Page_455">[Pg 455]</span> -breathed the quantities of a quart and two quarts generally mingled -with more than equal parts of oxygene or common air. In the most -decisive of those trials, its effects appeared to be depressing, and -I imagined that it produced a tendency to fainting: the pulse was -certainly rendered slower under its operation.</p> - -<p id="RIV_DI_01">At this time, Mr. Southey respired it in an highly diluted state; it -occasioned a slight degree of giddiness, and considerably diminished -the quickness of his pulse.</p> - -<p>Mr. C. Coates likewise respired it highly diluted, with similar effects.</p> - -<p>In April, I obtained nitrous oxide in a state of purity, and -ascertained many of its chemical properties. Reflections upon these -properties and upon the former trials, made me resolve to endeavour -to inspire it in its pure form, for I saw no other way in which its -respirability, or powers could be determined.<a id="FNanchor_205" href="#Footnote_205" class="fnanchor">[205]</a></p> - -<p><span class="pagenum" id="Page_456">[Pg 456]</span> -I was aware of the danger of this experiment. It certainly would never -have been made if the hypothesis of Dr. Mitchill had in the least -influenced my mind. I thought that the effects might be possibly -depressing and painful, but there were many reasons which induced me -to believe that a single inspiration of a gas apparently possessing -no immediate action on the irritable fibre, could neither destroy or -materially injure the powers of life.</p> - -<p>On April 11th, I made the first inspiration of pure nitrous oxide; -it passed through the bronchia without stimulating the glottis, and -produced no uneasy feeling in the lungs.</p> - -<p>The result of this experiment, proved that the gas was respirable, and -induced me to believe that a farther trial of its effects might be made -without danger.</p> - -<p>On April 16th, Dr. Kinglake being accidentally present, I breathed -three quarts of nitrous oxide from and into a silk bag for more than -half a minute, without previously closing my nose or exhausting my lungs. -<span class="pagenum" id="Page_457">[Pg 457]</span></p> - -<p>The first inspirations occasioned a slight degree of giddiness. This -was succeeded by an uncommon sense of fulness of the head, accompanied -with loss of distinct sensation and voluntary power, a feeling -analogous to that produced in the first stage of intoxication; but -unattended by pleasurable sensation. Dr. Kinglake, who felt my pulse, -informed me that it was rendered quicker and fuller.</p> - -<p>This trial did not satisfy me with regard to its powers; comparing it -with the former ones I was unable to determine whether the operation -was stimulant or depressing.</p> - -<p>I communicated the result to Dr. Beddoes, and on April the 17th, he was -present, when the following experiment was made.</p> - -<p>Having previously closed my nostrils and exhausted my lungs, I breathed -four quarts of nitrous oxide from and into a silk bag. The first -feelings were similar to those produced in the last experiment; but -in less than half a minute, the respiration being continued, they -<span class="pagenum" id="Page_458">[Pg 458]</span> -diminished gradually, and were succeeded by a sensation analogous to -gentle pressure on all the muscles, attended by an highly pleasurable -thrilling, particularly in the chest and the extremities. The objects -around me became dazzling and my hearing more acute. Towards the last -inspirations, the thrilling increased, the sense of muscular power -became greater, and at last an irresistible propensity to action was -indulged in; I recollect but indistinctly what followed; I know that my -motions were various and violent.</p> - -<p id="RIV_DI_02">These effects very soon ceased after respiration. In ten minutes, -I had recovered my natural state of mind. The thrilling in the extremities, -continued longer than the other sensations.<a id="FNanchor_206" href="#Footnote_206" class="fnanchor">[206]</a></p> - -<p>This experiment was made in the morning; no languor or exhaustion was -consequent, my feelings throughout the day were as usual, and I passed -the night in undisturbed repose. -<span class="pagenum" id="Page_459">[Pg 459]</span></p> - -<p>The next morning the recollections of the effects of the gas were -very indistinct, and had not remarks written immediately after the -experiment recalled them to my mind, I should have even doubted of -their reality. I was willing indeed to attribute some of the strong -emotion to the enthusiasm, which I supposed must have been necessarily -connected with the perception of agreeable feelings, when I was -prepared to experience painful sensations. Two experiments however, -made in the course of this day, with sceptism, convinced me that the -effects were solely owing to the specific operation of the gas.</p> - -<p>In each of them I breathed five quarts of nitrous oxide for rather a -longer time than before. The sensations produced were similar, perhaps -not quite so pleasurable; the muscular motions were much less violent.</p> - -<p>Having thus ascertained the powers of the gas, I made many experiments -to ascertain the length of time for which it might be breathed with -<span class="pagenum" id="Page_460">[Pg 460]</span> -safety, its effects on the pulse, and its general effects on the health -when often respired.</p> - -<p>I found that I could breathe nine quarts of nitrous oxide for three -minutes, and twelve quarts for rather more than four. I could never -breathe it in any quantity, so long as five minutes. Whenever its -operation was carried to the highest extent, the pleasurable thrilling -at its height about the middle of the experiment, gradually diminished, -the sense of pressure on the muscles was lost; impressions ceased to be -perceived; vivid ideas passed rapidly through the mind, and voluntary -power was altogether destroyed, so that the mouth-piece generally dropt -from my unclosed lips.</p> - -<p>Whenever the gas was in a high state of purity, it tasted distinctly -sweet to the tongue and palate, and had an agreeable odor. I often -thought that it produced a feeling somewhat analogous to taste, in -its application to my lungs. In one or two experiments, I perceived a -distinct sense of warmth in my chest. -<span class="pagenum" id="Page_461">[Pg 461]</span></p> - -<p>I never felt from it any thing like oppressive respiration: my -inspirations became deep in proportion as I breathed it longer; -but this phænomenon arose from increased energy of the muscles of -respiration, and from a desire of increasing the pleasurable feelings.</p> - -<p>Generally when I breathed from six to seven quarts, muscular motions -were produced to a certain extent; sometimes I manifested my pleasure -by stamping or laughing only; at other times, by dancing round the room -and vociferating.</p> - -<p>After the respiration of small doses, the exhilaration generally lasted -for five or six minutes only. In one or two experiments when ten quarts -had been breathed for near four minutes, an exhilaration and a sense of -slight intoxication lasted for two or three hours.</p> - -<p>On May 3d. To ascertain whether the gas would accelerate or retard the -progress of sleep, I breathed at about 8 o’clock in the evening, 25 -quarts of nitrous oxide, in quantities of six at a time, allowing but -short intervals between each dose. The feelings were much less -<span class="pagenum" id="Page_462">[Pg 462]</span> -pleasurable than usual, and during the consumption of the two last -doses, almost indifferent; indeed the gas was breathed rather too soon -after its production and contained some suspended acid vapour which -stimulated the lungs so as to induce coughing.</p> - -<p>After the experiments, for the first time I was somewhat depressed and -debilitated; my propensity to sleep however, came on at the usual hour, -and as usual was indulged in, my repose was sound and unbroken.</p> - -<p>Between May and July, I habitually breathed the gas, occasionally three -or four times a day for a week together; at other periods, four or five -times a week only.</p> - -<p>The doses were generally from six to nine quarts; their effects -appeared undiminished by habit, and were hardly ever exactly similar. -Sometimes I had the feelings of intense intoxication, attended with but -little pleasure; at other times, sublime emotions connected with highly -vivid ideas; my pulse was generally increased in fulness, but rarely in velocity. -<span class="pagenum" id="Page_463">[Pg 463]</span></p> - -<p>The general effects of its operation upon my health and state of mind, -are extremely difficult of description; nor can I well discriminate -between its agency and that of other physical and moral causes.</p> - -<p>I slept much less than usual, and previous to sleep, my mind was long -occupied by visible imagery. I had a constant desire of action, a -restlessness, and an uneasy feeling about the præcordia analogous to -the sickness of hope.</p> - -<p>But perhaps these phænomena in some measure depended on the interest -and labour connected with the experimental investigation relating -to the production of nitrous oxide, by which I was at this time -incessantly occupied.</p> - -<p>My appetite was as usual, and my pulse not materially altered. -Sometimes for an hour after the inspiration of the gas, I experienced -a species of mental indolence<a id="FNanchor_207" href="#Footnote_207" class="fnanchor">[207]</a> -pleasing rather than otherwise, and never ending in listlessness. -<span class="pagenum" id="Page_464">[Pg 464]</span></p> - -<p id="RIV_DI_03">During the last week in which I breathed it -uniformly, I imagined that I had increased sensibility of touch: my -fingers were pained by any thing rough, and the tooth edge produced -from slighter causes than usual. I was certainly more irritable, and -felt more acutely from trifling circumstances. My bodily strength was -rather diminished than increased.</p> - -<p>At the end of July, I left off my habitual course of respiration; -but I continued occasionally to breathe the gas, either for the sake -of enjoyment, or with a view of ascertaining its operation under -particular circumstances.</p> - -<p>In one instance, when I had head-ache from indigestion, it was -immediately removed by the effects of a large dose of gas; though it -afterwards returned, but with much less violence. In a second instance, -a slighter degree of head-ache was wholly removed by two doses of gas.</p> - -<p>The power of the immediate operation of the gas in removing intense -physical pain, I had a very good opportunity of ascertaining. -<span class="pagenum" id="Page_465">[Pg 465]</span></p> - -<p>In cutting one of the unlucky teeth called dentes sapientiæ, I -experienced an extensive inflammation of the gum, accompanied with -great pain, which equally destroyed the power of repose, and of -consistent action.</p> - -<p>On the day when the inflammation was most troublesome, I breathed -three large doses of nitrous oxide. The pain always diminished after -the first four or five inspirations; the thrilling came on as usual, -and uneasiness was for a few minutes, swallowed up in pleasure. As the -former state of mind however returned, the state of organ returned -with it; and I once imagined that the pain was more severe after the -experiment than before.</p> - -<p>In August, I made many experiments with a view of ascertaining whether -any analogy existed between the sensible effects of the different gases -which are sooner or later fatal to life when respired, and those of -nitrous oxide. -<span class="pagenum" id="Page_466">[Pg 466]</span></p> - -<p id="RIV_DI_04">I respired four quarts of Hydrogene<a id="FNanchor_208" href="#Footnote_208" class="fnanchor">[208]</a> -nearly pure produced from zinc and muriatic acid, for near a minute, -my lungs being previously exhausted and my nostrils carefully closed. -The first six or seven inspirations produced no sensations whatever; -in half a minute, I perceived a disagreeable oppression of the chest, -which obliged me to respire very quickly; this oppression gradually -increased, till at last the pain of suffocation compelled me to leave -off breathing. I felt no giddiness during or after the experiment; my -pulse was rendered feebler and quicker; and a by-stander informed me -that towards the last, my cheeks became purple.</p> - -<p>In a second experiment, when the hydrogene was procured from iron and -diluted sulphuric acid, I was unable to respire it for so long as three -quarters of a minute; a transient giddiness and muscular debility -were produced, the pulse was rendered very feeble, and the pain of -suffocation was greater than before.</p> - -<p id="RIV_DI_05">I breathed three quarts of Nitrogene mingled with a very small -portion of carbonic acid, for near a minute. It produced no alteration in my -<span class="pagenum" id="Page_467">[Pg 467]</span> -sensations for the first twenty seconds; then the painful sense -of suffocation gradually came on, and increased rapidly in the -last quarter of the minute, so as to oblige me to desist from the -experiment. My pulse was rendered feebler and quicker. I felt no -affection whatever in the head.</p> - -<p id="RIV_DI_06">Mr. Watt’s observations on the respiration of diluted Hydrocarbonate -by men, and Dr. Beddoes’s experiments on the destruction of animals by -pure hydrocarbonate, proved that its effects were highly deleterious.</p> - -<p>As it destroyed life apparently by rendering the muscular fibre -inirritable without producing any previous excitement, I was anxious -to compare its sensible effects with those of nitrous oxide, which at -this time I believed to destroy life by producing the highest possible -excitement, ending in læsion of organisation.</p> - -<p>In the first experiment, I breathed for near a minute, three quarts of -hydrocarbonate mingled with nearly two quarts of atmospheric air.<a id="FNanchor_209" href="#Footnote_209" class="fnanchor">[209]</a> -It produced a slight giddiness and pain in the head, and a momentary loss -<span class="pagenum" id="Page_468">[Pg 468]</span> -of voluntary power: my pulse was rendered much quicker and feebler. -These effects however, went off in five minutes, and I had no return of -giddiness.</p> - -<p>Emboldened by this trial, in which the feelings were not unlike those -I experienced in the first experiments on nitrous oxide, I resolved to -breathe pure hydrocarbonate.</p> - -<p>For this purpose, I introduced into a silk bag, four quarts of gas -nearly pure, which was carefully produced from the decomposition of -water by charcoal an hour before, and which had a very strong and -disagreeable smell.</p> - -<p>My friend, Mr. James Tobin, Junr. being present, after a forced -exhaustion of my lungs, the nose being accurately closed, I made -three inspirations and expirations of the hydrocarbonate. The first -inspiration produced a sort of numbness and loss of feeling in the -chest and about the pectoral muscles. After the second inspiration, -I lost all power of perceiving external things, and had no distinct -<span class="pagenum" id="Page_469">[Pg 469]</span> -sensation except a terrible oppression on the chest. During the -third expiration, this feeling disappeared, I seemed sinking into -annihilation, and had just power enough to drop the mouth-piece from -my unclosed lips. A short interval must have passed during which I -respired common air, before the objects about me were distinguishable. -On recollecting myself, I faintly articulated, “<i>I do not think -I shall die</i>.” Putting my finger on the wrist, I found my pulse -thread-like and beating with excessive quickness.</p> - -<p>In less than a minute, I was able to walk, and the painful oppression -on the chest directed me to the open air.</p> - -<p>After making a few steps which carried me to the garden, my head -became giddy, my knees trembled, and I had just sufficient voluntary -power to throw myself on the grass. Here the painful feeling of the -chest increased with such violence as to threaten suffocation. At this -moment, I asked for some nitrous oxide. Mr. Dwyer brought me a mixture -of oxygene and nitrous oxide. I breathed this for a minute, and -<span class="pagenum" id="Page_470">[Pg 470]</span> -<i>believed</i> myself relieved. In five minutes, the painful feelings -began gradually to diminish. In an hour they had nearly disappeared, -and I felt only excessive weakness and a slight swimming of the head. -My voice was very feeble and indistinct. This was at two o’clock in the -afternoon.</p> - -<p>I afterwards walked slowly for about half an hour, with Mr. Tobin, -Junr. and on my return, was so much stronger and better, as to believe -that the effects of the gas had disappeared; though my pulse was 120 -and very feeble. I continued without pain for near three quarters of an -hour; when the giddiness returned with such violence as to oblige me -to lie on the bed; it was accompanied with nausea, loss of memory, and -deficient sensation. In about an hour and half, the giddiness went off, -and was succeeded by an excruciating pain in the forehead and between -the eyes, with transient pains in the chest and extremities. -<span class="pagenum" id="Page_471">[Pg 471]</span> -Towards night these affections gradually diminished. At ten,<a id="FNanchor_210" href="#Footnote_210" class="fnanchor">[210]</a> -no disagreeable feeling except weakness remained. I slept sound, and -awoke in the morning very feeble and very hungry. No recurrence of the -symptoms took place, and I had nearly recovered my strength by the evening.</p> - -<p>I have been minute in the account of this experiment because it -proves, that hydrocarbonate acts as a sedative, i. e. that it -produces diminution of vital action, and debility, without previously -exciting. There is every reason to believe, that if I had taken four -or five inspirations instead of three, they would have destroyed life -immediately without producing any painful sensation. Perhaps most of -the uneasy feelings after the experiment, were connected with the -return of the healthy condition of organs.<a id="FNanchor_211" href="#Footnote_211" class="fnanchor">[211]</a></p> - -<p id="RIV_DI_07"><span class="pagenum" id="Page_472">[Pg 472]</span> -About a week after this experiment, I attempted to respire Carbonic -acid, not being at the time acquainted with the experiments of Rosier.</p> - -<p>I introduced into a silk bag four quarts of well washed carbonic acid -produced from carbonate of ammoniac<a id="FNanchor_212" href="#Footnote_212" class="fnanchor">[212]</a> -by heat, and after a compleat voluntary exhaustion of my lungs, -attempted to inspire it. It tasted strongly acid in the mouth and -fauces, and produced a sense of burning at the top of the uvula. In -vain I made powerful voluntary efforts to draw it into the windpipe; -at the moment that the epiglottis was raised a little, a painful -stimulation was induced, so as to close it spasmodically on the -glottis; and thus in repeated trials I was prevented from taking a -single particle of carbonic acid into my lungs. -<span class="pagenum" id="Page_473">[Pg 473]</span></p> - -<p>I tried to breathe a mixture of two quarts of common air and three of -carbonic acid, without success; it stimulated the epiglottis nearly in -the same manner as pure carbonic acid, and was perfectly non-respirable.</p> - -<p>I found that a mixture of three quarts of carbonic acid with seven of -common air was respirable, I breathed it for near a minute. At the -time, it produced a slight degree of giddiness, and an inclination to -sleep. These effects however, very rapidly disappeared after I had -ceased to breathe,<a id="FNanchor_213" href="#Footnote_213" class="fnanchor">[213]</a> -and no other affections followed.</p> - -<p>During the course of experiments on nitrous oxide, I several times -breathed Oxygene procured from manganese by heat, for from three to -five minutes. -<span class="pagenum" id="Page_474">[Pg 474]</span></p> - -<p>In respiring eight or ten quarts; for the first two or three minutes -I could perceive no effects. Towards the end, even when I breathed -very slowly, my respiration became oppressed, and I felt a sensation -analogous to that produced by the want of fresh air; though but little -of the oxygene had been consumed.</p> - -<p id="RIV_DI_08">In one experiment when I breathed from and into a bag containing 20 -quarts of oxygene for near six minutes; Dr. Kinglake felt my pulse, -and found it not altered in velocity, but rather harder than before. I -perceived no effects but those of oppression on the chest<a id="FNanchor_214" href="#Footnote_214" class="fnanchor">[214]</a>.</p> - -<p id="RIV_DI_09"><span class="pagenum" id="Page_475">[Pg 475]</span> -Having observed in my experiments upon venous blood, that Nitrous gas -rendered that fluid of a purple tinge, very like the color generated -in it by nitrous oxide; and finding no painful effects produced by -the application of nitrous gas to the bare muscular fibre, I began to -imagine that this gas might be breathed with impunity, provided it were -possible in any way to free the lungs of common air before inspiration, -so as to prevent the formation of nitrous acid.</p> - -<p>On this supposition, during a fit of enthusiasm produced by the -respiration of nitrous oxide, I resolved to endeavour to breathe -Nitrous gas.</p> - -<p>114 cubic inches of nitrous gas were introduced into the large -<span class="pagenum" id="Page_476">[Pg 476]</span> -mercurial airholder; two small silk bags of the capacity of seven -quarts were filled with nitrous oxide.</p> - -<p>After a forced exhaustion of my lungs, my nose being accurately closed, -I made three inspirations and expirations of nitrous oxide in one -of the bags, to free my lungs as much as possible from atmospheric -oxygene; then, after a full expiration of the nitrous oxide, I -transferred my mouth from the mouth-piece of the bag to that of the -airholder, and turning the stop-cock, attempted to inspire the nitrous -gas.—In passing through my mouth and fauces, it tasted astringent and -highly disagreeable; it occasioned a sense of burning in the throat, -and produced a spasm of the epiglottis so painful as to oblige me to -desist instantly from attempts to inspire it. After moving my lips from -the mouth-piece, when I opened them to inspire common air, aëriform -nitrous acid was instantly formed in my mouth, which burnt the tongue -and palate, injured the teeth, and produced an inflammation of the -mucous membrane which lasted for some hours. -<span class="pagenum" id="Page_477">[Pg 477]</span></p> - -<p>As after the respiration of nitrous oxide in the experiments in the -last Research, a small portion of the residual atmospheric air remained -in the lungs, mingled with the gas, after forced expiration; it is -most probable that a minute portion of nitrous acid was formed in this -experiment, when the nitrous gas was taken into the mouth and fauces, -which might produce its stimulating properties. If so, perhaps I owe my -life to the circumstance; for supposing I had taken an inspiration of -nitrous gas, and even that it had produced no positive effects, it is -highly improbable, that by breathing nitrous oxide, I should have freed -my lungs from it, so as to have prevented the formation of nitrous acid -when I again inspired common air. I never design again to attempt so -rash an experiment.</p> - -<p>In the beginning of September I often respired nitrous oxide mingled -with different proportions of common air or oxygene. The effects -produced by the diluted gas were much less violent than those produced -<span class="pagenum" id="Page_478">[Pg 478]</span> -by pure nitrous oxide. They were generally pleasant: the thrilling was -not often perceived, but a sense of exhilaration was almost constant.</p> - -<p>Between September and the end of October, I made but few experiments -on respiration, almost the whole of my time being devoted to chemical -experiments on the production and analysis of nitrous oxide.</p> - -<p>At this period my health being somewhat injured by the constant labour -of experimenting, and the perpetual inhalation of the acid vapours of -the laboratory, I went into Cornwall; where new associations of ideas -and feelings, common exercise, a pure atmosphere, luxurious diet and -moderate indulgence in wine, in a month restored me to health and vigor.</p> - -<p>Nov. 27th. Immediately after my return, being fatigued by a long -journey, I respired nine quarts of nitrous oxide, having been precisely -thirty-three days without breathing any. The feelings were different -from those I had experienced in former experiments. After the first six -<span class="pagenum" id="Page_479">[Pg 479]</span> -or seven inspirations, I gradually began to lose the perception of -external things, and a vivid and intense recollection of some former -experiments passed through my mind, so that I called out “<i>what an -amazing concatenation of ideas!</i>” I had no pleasurable feeling -whatever, I used no muscular motion, nor did I feel any disposition -to it; after a minute, when I made the note of the experiment, all -the uncommon sensations had vanished; they were succeeded by a slight -soreness in one of the arms and in the leg: in three minutes these -affections likewise disappeared.</p> - -<p>From this experiment I was inclined to suppose that my newly acquired -health had diminished my susceptibility to the effects of the gas. -About ten days after, however, I had an opportunity of proving the -fallacy of this supposition.</p> - -<p>Immediately after a journey of 126 miles, in which I had no sleep the -preceding night, being much exhausted, I respired seven quarts of gas -for near three minutes. It produced the usual pleasurable effects, and -<span class="pagenum" id="Page_480">[Pg 480]</span> -slight muscular motion. I continued exhilarated for some minutes -afterwards: but in half an hour found myself neither more or less -exhausted than before the experiment. I had a great propensity to sleep.</p> - -<p>I repeated the experiment four or five times in the following week, -with similar effects. My susceptibility was certainly not diminished. I -even thought that I was more affected than formerly by equal doses.</p> - -<p>Though, except in one instance, when indeed the gas was impure, I had -experienced no decisive exhaustion after the excitement from nitrous -oxide, yet still I was far from being satisfied that it was unanalogous -to stimulants in general.—No experiment had been made in which the -excitement from nitrous oxide had been kept up for so great a length of -time and carried to so great an extent as that in which it is uniformly -succeeded by excessive debility under the agency of other powers.</p> - -<p>It occurred to me, that supposing nitrous oxide to be a stimulant of -the common class, it would follow that the debility produced in -<span class="pagenum" id="Page_481">[Pg 481]</span> -consequence of excessive stimulation by a known agent, ought to be -<i>increased</i> after excitement from nitrous oxide.<a id="FNanchor_215" href="#Footnote_215" class="fnanchor">[215]</a></p> - -<p>To ascertain whether this was the case, I made on December 23d, at -four P. M. the following experiment. I drank a bottle of wine in -large draughts in less than eight minutes. Whilst I was drinking, -I perceived a sense of fulness in the head, and throbbing of the -arteries, not unanalogous to that produced in the first stage of -nitrous oxide excitement. After I had finished the bottle, this fulness -increased, the objects around me became dazzling, the power of distinct -articulation was lost, and I was unable to walk steadily. At this -moment the sensations were rather pleasurable than otherwise, the sense -of fulness in the head soon however increased so as to become painful, -<span class="pagenum" id="Page_482">[Pg 482]</span> -and in less than an hour I sunk into a state of -insensibility.<a id="FNanchor_216" href="#Footnote_216" class="fnanchor">[216]</a></p> - -<p>In this situation I must have remained for two hours or two hours and half.</p> - -<p>I was awakened by head-ache and painful nausea. The nausea continued -even after the contents of the stomach had been ejected. The pain in -the head every minute increased; I was neither feverish or thirsty; my -bodily and mental debility were excessive, and the pulse feeble and quick.</p> - -<p>In this state I breathed for near a minute and half five quarts of gas, -which was brought to me by the operator for nitrous oxide; but as it -produced no sensations whatever, and apparently rather increased my -debility, I am almost convinced that it was from some accident, either -common air, or very impure nitrous oxide. -<span class="pagenum" id="Page_483">[Pg 483]</span></p> - -<p>Immediately after this trial, I respired 12 quarts of oxygene for near -four minutes. It produced no alteration in my sensations at the time; -but immediately after I imagined that I was a little exhilarated.</p> - -<p>The head-ache and debility still however continuing with violence, I -examined some nitrous oxide which had been prepared in the morning, and -finding it very pure, respired seven quarts of it for two minutes and half.</p> - -<p>I was unconscious of head-ache after the third inspiration; the usual -pleasurable thrilling was produced, voluntary power was destroyed, and -vivid ideas rapidly passed through my mind; I made strides across the -room, and continued for some minutes much exhilarated. Immediately -after the exhilaration had disappeared, I felt a slight return of the -head-ache; it was connected with transient nausea. After two minutes, -when a small quantity of acidified wine had been thrown from the -stomach, both the nausea and head-ache disappeared; but languor and -depression not very different in degree from those existing before the -<span class="pagenum" id="Page_484">[Pg 484]</span> -experiment, succeeded. They however, gradually went off before bed -time. I slept sound the whole of the night except for a few minutes, -during which I was kept awake by a trifling head-ache. In the morning, -I had no longer any debility. No head-ache or giddiness came on after I -had arisen, and my appetite was very great.</p> - -<p>This experiment proved, that debility from intoxication was not -increased by excitement from nitrous oxide. The head-ache and -depression, it is probable, would have continued longer if it had not -been administered. Is it not likely that the slight nausea following -the effects of the gas was produced by new excitability given to the -stomach?</p> - -<p id="RIV_DI_10">To ascertain with certainty, whether the most extensive action -of nitrous oxide compatible with life, was capable of producing debility, -I resolved to breathe the gas for such a time and in such quantities, -as to produce excitement equal in duration and superior in intensity to -that occasioned by high intoxication from opium or alcohol. -<span class="pagenum" id="Page_485">[Pg 485]</span></p> - -<p>To habituate myself to the excitement, and to carry it on gradually.</p> - -<p>On December 26th, I was inclosed in an air-tight breathing-box,<a id="FNanchor_217" href="#Footnote_217" class="fnanchor">[217]</a> -of the capacity of about 9 cubic feet and half, in the presence of Dr. Kinglake.</p> - -<p>After I had taken a situation in which I could by means of a curved -thermometer inserted under the arm, and a stop-watch, ascertain the -alterations in my pulse and animal heat, 20 quarts of nitrous oxide -were thrown into the box.</p> - -<p>For three minutes I experienced no alteration in my sensations, though -immediately after the introduction of the nitrous oxide the smell and -taste of it were very evident.<a id="FNanchor_218" href="#Footnote_218" class="fnanchor">[218]</a></p> - -<p><span class="pagenum" id="Page_486">[Pg 486]</span> -In four minutes I began to feel a slight glow in the cheeks, and a -generally diffused warmth over the chest, though the temperature of the -box was not quite 50°. I had neglected to feel my pulse before I went -in; at this time it was 104 and hard, the animal heat was 98°. In ten -minutes the animal heat was near 99°, in a quarter of an hour 99.5°, -when the pulse was 102, and fuller than before.</p> - -<p>At this period 20 quarts more of nitrous oxide were thrown into the -box, and well-mingled with the mass of air by agitation.</p> - -<p>In 25 minutes the animal heat was 100°, pulse 124. In 30 minutes, -20 quarts more of gas were introduced.</p> - -<p>My sensations were now pleasant; I had a generally diffused warmth -without the slightest moisture of the skin, a sense of exhilaration -similar to that produced by a small dose of wine, and a disposition to -muscular motion and to merriment.</p> - -<p>In three quarters of an hour the pulse was 104, and animal heat not -<span class="pagenum" id="Page_487">[Pg 487]</span> -99,5°, the temperature of the chamber was 64°. The pleasurable feelings -continued to increase, the pulse became fuller and slower, till in -about an hour it was 88, when the animal heat was 99°.</p> - -<p>20 quarts more of air were admitted. I had now a great disposition to -laugh, luminous points seemed frequently to pass before my eyes, my -hearing was certainly more acute and I felt a pleasant lightness and -power of exertion in my muscles. In a short time the symptoms became -stationary; breathing was rather oppressed, and on account of the great -desire of action, rest was painful.</p> - -<p>I now came out of the box, having been in precisely an hour and quarter.</p> - -<p>The moment after, I began to respire 20 quarts of unmingled nitrous -oxide. A thrilling extending from the chest to the extremities was -almost immediately produced. I felt a sense of tangible extension -highly pleasurable in every limb; my visible impressions were dazzling -and apparently magnified, I heard distinctly every sound in the room -<span class="pagenum" id="Page_488">[Pg 488]</span> -of my situation.<a id="FNanchor_219" href="#Footnote_219" class="fnanchor">[219]</a> -By degrees as the pleasurable and was perfectly aware sensations -increased, I lost all connection with external things; trains of vivid -visible images rapidly passed through my mind and were connected with -words in such a manner, as to produce perceptions perfectly novel. -I existed in a world of newly connected and newly modified ideas. I -theorised; I imagined that I made discoveries. When I was awakened -from this semi-delirious trance by Dr. Kinglake, who took the bag from -my mouth, Indignation and pride were the first feelings produced by -the sight of the persons about me. My emotions were enthusiastic and -sublime; and for a minute I walked round the room perfectly regardless -of what was said to me. As I recovered my former state of mind, I felt -an inclination to communicate the discoveries I had made during the -experiment. I endeavoured to recall the ideas, they were feeble and -indistinct; one collection of terms, however, presented -<span class="pagenum" id="Page_489">[Pg 489]</span> -itself: and with the most intense belief and prophetic manner, I -exclaimed to Dr. Kinglake, “<i>Nothing exists but thoughts!—the -universe is composed of impressions, ideas, pleasures and pains!</i>”</p> - -<p>About three minutes and half only, had elapsed during this experiment, -though the time as measured by the relative vividness of the -recollected ideas, appeared to me much longer.</p> - -<p>Not more than half of the nitrous oxide was consumed. After a minute, -before the thrilling of the extremities had disappeared, I breathed the -remainder. Similar sensations were again produced; I was quickly thrown -into the pleasurable trance, and continued in it longer than before. -For many minutes after the experiment, I experienced the thrilling -in the extremities, the exhilaration continued nearly two hours. For -a much longer time I experienced the mild enjoyment before described -connected with indolence; no depression or feebleness followed. I ate -my dinner with great appetite and found myself lively and disposed to -action immediately after. I passed the evening in executing experiments. -<span class="pagenum" id="Page_490">[Pg 490]</span> -At night I found myself unusually cheerful and active; and the hours -between eleven and two, were spent in copying the foregoing detail -from the common-place book and in arranging the experiments. In bed -I enjoyed profound repose. When I awoke in the morning, it was with -consciousness of pleasurable existence, and this consciousness more or -less, continued through the day.</p> - -<p>Since December, I have very often breathed nitrous oxide. My -susceptibility to its power is rather increased than diminished. I -find six quarts a full dose, and I am rarely able to respire it in any -quantity for more than two minutes and half.</p> - -<p>The mode of its operation is somewhat altered. It is indeed very -different at different times.</p> - -<p>I am scarcely ever excited into violent muscular action, the emotions -are generally much less intense and sublime than in the former -experiments, and not often connected with thrilling in the extremities. -<span class="pagenum" id="Page_491">[Pg 491]</span></p> - -<p>When troubled with indigestion, I have been two or three times -unpleasantly affected after the excitement of the gas. Cardialgia, -eructations and unpleasant fulness of the head were produced.</p> - -<p>I have often felt very great pleasure when breathing it alone, in -darkness and silence, occupied only by ideal existence. In two or three -instances when I have breathed it amidst noise, the sense of hearing -has been painfully affected even by moderate intensity of sound. The -light of the sun has sometimes been disagreeably dazzling. I have once -or twice felt an uneasy sense of tension in the cheeks and transient -pains in the teeth.</p> - -<p>Whenever I have breathed the gas after excitement from moral or -physical causes, the delight has been often intense and sublime.</p> - -<p>On May 5th, at night, after walking for an hour amidst the scenery -of the Avon, at this period rendered exquisitely beautiful by bright -<span class="pagenum" id="Page_492">[Pg 492]</span> -moonshine; my mind being in a state of agreeable feeling, I respired -six quarts of newly prepared nitrous oxide.</p> - -<p>The thrilling was very rapidly produced. The objects around me were -perfectly distinct, and the light of the candle not as usual dazzling. -The pleasurable sensation was at first local and perceived in the -lips and about the cheeks. It gradually however, diffused itself -over the whole body, and in the middle of the experiment was for a -moment so intense and pure as to absorb existence. At this moment, and -not before, I lost consciousness; it was however, quickly restored, -and I endeavoured to make a by-stander acquainted with the pleasure -I experienced by laughing and stamping. I had no vivid ideas. The -thrilling and the pleasurable feeling continued for many minutes; -I felt two hours afterwards, a slight recurrence of them, in the -intermediate state between sleeping and waking; and I had during the -whole of the night, vivid and agreeable dreams. I awoke in the morning -with the feeling of restless energy, or that desire of action connected -<span class="pagenum" id="Page_493">[Pg 493]</span> -with no definite object, which I had often experienced in the course of -experiments in 1799.</p> - -<p>I have two or three times since respired nitrous oxide under similar -circumstances; but never with equal pleasure.</p> - -<p>During the last fortnight, I have breathed it very often; the effects -have been powerful and the sensations uncommon; but pleasurable only in -a slight degree.</p> - -<p>I ought to have observed that a desire to breathe the gas is always -awakened in me by the sight of a person breathing, or even by that of -an air-bag or an airholder.</p> - -<p>I have this day, June 5th, respired four large doses of gas. The -first two taken in the morning acted very powerfully; but produced -no thrilling or other pleasurable feelings. The effects of the third -breathed immediately after a hearty dinner were pleasant, but neither -intense or intoxicating. The fourth was respired at night in darkness -and silence after the occurrence of a circumstance which had produced -<span class="pagenum" id="Page_494">[Pg 494]</span> -some anxiety. This dose affected me powerfully and pleasantly; a slight -thrilling in the extremities was produced; an exhiliration continued -for some time, and I have had but little return of uneasiness. 11 P. M.</p> - -<p>From the nature of the language of feeling, the preceding detail -contains many imperfections; I have endeavoured to give as accurate an -account as possible of the strange effects of nitrous oxide, by making -use of terms standing for the most similar common feelings.</p> - -<p>We are incapable of recollecting pleasures and pains of sense.<a id="FNanchor_220" href="#Footnote_220" class="fnanchor">[220]</a> -It is impossible to reason concerning them, except by means of terms which -have been associated with them at the moment of their existence, and -which are afterwards called up amidst trains of concomitant ideas. -<span class="pagenum" id="Page_495">[Pg 495]</span></p> - -<p>When pleasures and pains are new or connected with new ideas, they can -never be intelligibly detailed unless associated during their existence -with terms standing for analogous feelings.</p> - -<p>I have sometimes experienced from nitrous oxide, sensations similar to -no others, and they have consequently been indescribable. This has been -likewise often the case with other persons. Of two paralytic patients -<span class="pagenum" id="Page_496">[Pg 496]</span> -who were asked what they felt after breathing nitrous oxide, the first -answered, “<i>I do not know how, but very queer.</i>” The second said, -“<i>I felt like the sound of a harp.</i>” Probably in the one case, no -analogous feelings had ever occurred. In the other, the pleasurable -thrillings were similar to the sensations produced by music; and hence, -they were connected with terms formerly applied to music. -<span class="pagenum" id="Page_497">[Pg 497]</span></p> - -<h3 id="RIV_DIV_II">DIVISION II.</h3> - -<p class="neg-indent"><i>DETAILS of the EFFECTS produced by the RESPIRATION -of NITROUS OXIDE upon different INDIVIDUALS furnished by THEMSELVES.</i></p> - -<p class="drop-cap"><span class="smcap">The</span> experiments -related in the following details, were made in the Medical Pneumatic -Institution.</p> - -<p>Abstracts from many of them have been published by -Dr. Beddoes.<a id="FNanchor_221" href="#Footnote_221" class="fnanchor">[221]</a></p> - -<div class="blockquot2"> -<p id="RIV_DII_01" class="f120 space-above1">I. <i>Detail of</i> -<span class="smcap">Mr. J. W. Tobin</span>.</p> - -<p>Having seen the remarkable effects produced on Mr. Davy, by breathing -nitrous oxide, the 18th of April; I became desirous of taking some. -<span class="pagenum" id="Page_498">[Pg 498]</span></p> - -<p>A day or two after I breathed 2 quarts of this gas, returning it back -again into the same bag, after two or three in inspirations, breathing -became difficult, and I occasionally admitted common air into my -lungs. While the respiration was continued, my sensations became more -pleasant. On taking the bag from my mouth, I staggered a little, but -felt no other effect.</p> - -<p>On the second time of making the experiment, I took nearly four quarts, -but still found it difficult to continue breathing long, though the air -which was left in the bag was far from being impure.</p> - -<p>The effects however, in this case, were more striking than in the -former. Increased muscular action was accompanied by very pleasurable -feelings, and a strong desire to continue the inspiration. On removing -the bag from my mouth, I laughed, staggered, and attempted to speak, -but stammered exceedingly, and was utterly unable to pronounce some -words. My usual state of mind, however, soon returned.</p> - -<p>On the 29th, I again breathed four quarts. The pleasant feelings -<span class="pagenum" id="Page_499">[Pg 499]</span> -produced at first, urged me to continue the inspiration with great -eagerness. These feelings however, went off towards the end of the -experiment, and no other effects followed. The gas had probably been -breathed too long, as it would not support flame. I then proposed to -Mr. Davy, to inhale the air by the mouth from one bag, and to expire -it from the nose into another. This method was pursued with less than -three quarts, but the effects were so powerful as to oblige me to take -in a little common air occasionally. I soon found my nervous system -agitated by the highest sensations of pleasure, which are difficult of -description; my muscular powers were very much increased, and I went on -breathing with great vehemence, not from a difficulty of inspiration, -but from an eager avidity for more air. When the bags were exhausted -and taken from me, I continued breathing with the same violence, then -suddenly starting from the chair, and vociferating with pleasure, -I made towards those that were present, as I wished they should -<span class="pagenum" id="Page_500">[Pg 500]</span> -participate in my feelings. I struck gently at Mr. Davy and a stranger -entering the room at the moment, I made towards him, and gave him -several blows, but more in the spirit of good humour than of anger. I -then ran through different rooms in the house, and at last returned -to the laboratory somewhat more composed; my spirits continued much -elevated for some hours after the experiment, and I felt no consequent -depression either in the evening or the day following, but slept as -soundly as usual.</p> - -<p>On the 5th of May, I again attempted to breathe nitrous oxide, but -it happened to contain suspended nitrous vapour which rendered it -non-respirable.</p> - -<p>On the 7th, I inspired 7 quarts of pure gas mingled with an equal -quantity of common air, the sensations were pleasant, and my muscular -power much increased.</p> - -<p>On the 8th, I inspired five quarts without any mixture of common air, -but the effects were not equal to those produced the day before; Indeed -there were reasons for supposing that the gas was impure. -<span class="pagenum" id="Page_501">[Pg 501]</span></p> - -<p>On the 18th, I breathed nearly six quarts of the pure nitrous oxide. It -is not easy to describe my sensations; they were superior to any thing -I ever before experienced. My step was firm, and all my muscular powers -increased. My senses were more alive to every surrounding impression; -I threw myself into several theatrical attitudes, and traversed the -laboratory with a quick step; my mind was elevated to a most sublime -height. It is giving but a faint idea of the feelings to say, that they -resembled those produced by a representation of an heroic scene on the -stage, or by reading a sublime passage in poetry when circumstances -contribute to awaken the finest sympathies of the soul. In a few -minutes the usual state of mind returned. I continued in good spirits -for the rest of the day, and slept soundly.</p> - -<p>Since the 18th of May, I have very often breathed nitrous oxide. In -the first experiments when pure, its effects were generally similar to -those just described. -<span class="pagenum" id="Page_502">[Pg 502]</span></p> - -<p>Lately I have seldom experienced vivid sensations. The pleasure -produced by it is slight and tranquil, I rarely feel sublime emotions -or increased muscular power.</p> - -<p class="author"><span class="smcap">J. W. Tobin.</span></p> -<p><i>October, 1799.</i></p> - -<hr class="chap x-ebookmaker-drop" /> - -<p id="RIV_DII_02" class="f120 space-above1">II. <i>Detail of</i> -<span class="smcap">Mr. Wm. Clayfield</span>.</p> - -<p>The first time that I breathed the nitrous oxide, it produced feelings -analogous to those of intoxication. I was for some time unconscious of -existence, but at no period of the experiment experienced agreeable -sensations, a momentary nausea followed it; but unconnected with -languor or head-ache.</p> - -<p>After this I several times respired the gas, but on account of the -fulness in the head and apparent throbbing of the arteries in the -brain,<a id="FNanchor_222" href="#Footnote_222" class="fnanchor">[222]</a> -always desisted to breathe before the full effects were -produced. In two experiments however, when by powerful voluntary -efforts I succeeded in breathing a large quantity of gas for some -<span class="pagenum" id="Page_503">[Pg 503]</span> -minutes, I had highly pleasurable thrillings in the extremities, and -such increase of muscular power, as to be obliged to exert my limbs -with violence. After these experiments, no languor or depression followed.</p> - -<p class="author"><span class="smcap">William Clayfield.</span></p> - -<hr class="chap x-ebookmaker-drop" /> - -<p id="RIV_DII_03" class="f120 space-above1">III. <i>Letter from</i> -<span class="smcap">Dr. Kinglake</span>.</p> - -<p>In compliance with your desire, I will endeavour to give you a faithful -detail of the effects produced on my sensations by the inhalation of -nitrous oxide.</p> - -<p>My first inspiration of it was limited to four quarts, diluted with an -equal quantity of atmospheric air. After a few inspirations, a sense of -additional freedom and power (call it energy if you please) agreeably -pervaded the region of the lungs; this was quickly succeeded by an -almost delirious but highly pleasurable sensation in the brain, which -was soon diffused over the whole frame, imparting to the muscular power -at once an encreased disposition and tone for action; but the mental -<span class="pagenum" id="Page_504">[Pg 504]</span> -effect of the excitement was such as to absorb in a sort of -intoxicating placidity, and delight, volition, or rather the power -of voluntary motion. These effects were in a greater or less degree -protracted during about five minutes, when the former state returned, -with the difference however of feeling more cheerful and alert, for -several hours after.</p> - -<p>It seemed also to have had the further effect of reviving rheumatic -irritations in the shoulder and knee-joints, which had not been -previously felt for many months. No perceptible change was induced in -the pulse either at or subsequent to the time of inhaling the gas.</p> - -<p>The effects produced by a second trial of its powers, were more -extensive, and concentrated on the brain. In this instance, nearly six -quarts undiluted, were accurately and fully inhaled. As on the former -occasion, it immediately proved agreeably respirable, but before the -whole quantity was quite exhausted, its agency was exerted so strongly -on the brain, as progressively to suspend the senses of seeing, -hearing, feeling, and ultimately the power of volition itself. At this -<span class="pagenum" id="Page_505">[Pg 505]</span> -period, the pulse was much augmented both in force and frequency; -slight convulsive twitches of the muscles of the arms were also -induced; no painful sensation, nausea, or languor, however, either -preceded, accompanied, or followed this state, nor did a minute elapse -before the brain rallied, and resumed its wonted faculties, when -a sense of glowing warmth extending over the system, was speedily -succeeded by a re-instatement of the equilibrium of health.</p> - -<p>The more permanent effects were (as in the first experiment) an -invigorated feel of vital power, improved spirits, transient -irritations in different parts, but not so characteristically rheumatic -as in the former instance.</p> - -<p>Among the circumstances most worthy of regard in considering the -properties and administration of this powerful aërial agent, may be -ranked, the fact of its being (contrary to the prevailing opinion<a id="FNanchor_223" href="#Footnote_223" class="fnanchor">[223]</a>) -both highly respirable, and salutary, that it impresses the brain -<span class="pagenum" id="Page_506">[Pg 506]</span> -and system at large with a more or less strong and durable degree -of pleasurable sensation, that unlike the effect of other violently -exciting agents, no sensible exhaustion or diminution of vital power -accrues from the exertions of its stimulant property, that its most -excessive operation even, is neither permanently nor transiently -debilitating; and finally, that it fairly promises under judicious -application, to prove an extremely efficient remedy, as well in the -vast tribe of diseases originating from deficient irritability and -sensibility, as in those proceeding from morbid associations, and -modifications, of those vital principles. -<span class="pagenum" id="Page_507">[Pg 507]</span></p> - -<p>If you should deem any thing contained in this cursory narrative -capable of subserving in any degree the practical advantages likely to -result from your scientific and valuable investigation of the genuine -properties of the nitrous oxide, it is perfectly at your disposal.</p> - -<p class="author">I am<span class="ws10"> </span><br />Your sincere friend,<span class="ws2"> </span><br /> -<span class="smcap">Robert Kinglake</span>.</p> - -<p><i>Bristol, June 14th, 1799.</i><br /> -<span class="ws2"> </span>To <span class="smcap">Mr. Davy</span>.</p> - -<hr class="chap x-ebookmaker-drop" /> - -<p id="RIV_DII_04" class="f120 space-above1">IV. <i>Detail of</i> -<span class="smcap">Mr. Southey</span>.</p> - -<p>In breathing the nitrous oxide, I could not distinguish between the -first feelings it occasioned and an apprehension of which I was unable -to divest myself. My first definite sensation was a dizziness, a -fulness in the head, such as to induce a fear of falling. This was -momentary. When I took the bag from my mouth, I immediately laughed. -<span class="pagenum" id="Page_508">[Pg 508]</span> -The laugh was involuntary but highly pleasurable, accompanied by -a thrill all through me; and a tingling in my toes and fingers, a -sensation perfectly new and delightful. I felt a fulness in my chest -afterwards; and during the remainder of the day, imagined that my taste -and hearing were more than commonly quick. Certain I am that I felt -myself more than usually strong and chearful.</p> - -<p>In a second trial, by continuing the inhalation longer, I felt a thrill -in my teeth; and breathing still longer the third time, became so full -of strength as to be compelled to exercise my arms and feet.</p> - -<p>Now after an interval of some months, during which my health has been -materially impaired, the nitrous oxide produces an effect upon me -totally different. Half the quantity affects me, and its operation is -more violent; a slight laughter is first induced,<a id="FNanchor_224" href="#Footnote_224" class="fnanchor">[224]</a> -and a desire to continue the inhalation, which is counteracted by fear from -<span class="pagenum" id="Page_509">[Pg 509]</span> -the rapidity of respiration; indeed my breath becomes so short and quick, -that I have no doubt but the quantity which I formerly breathed, would -now destroy me. The sensation is not painful, neither is it in the -slightest degree pleasurable.</p> - -<p class="author"><span class="smcap">Robert Southey.</span></p> - -<hr class="chap x-ebookmaker-drop" /> - -<p id="RIV_DII_05" class="f120 space-above1">V. <i>Letter from</i> -<span class="smcap">Dr. Roget</span>.</p> - -<p>The effect of the first inspirations of the nitrous oxide was that of -making me vertiginous, and producing a tingling sensation in my hands -and feet: as these feelings increased, I seemed to lose the sense of -my own weight, and imagined I was sinking into the ground. I then felt -a drowsiness gradually steal upon me, and a disinclination to motion; -even the actions of inspiring and expiring were not performed without -effort: and it also required some attention of mind to keep my nostrils -<span class="pagenum" id="Page_510">[Pg 510]</span> -closed with my fingers. I was gradually roused from this torpor by -a kind of delirium, which came on so rapidly that the air-bag dropt -from my hands. This sensation increased for about a minute after I had -ceased to breathe, to a much greater degree than before, and I suddenly -lost sight of all the objects around me, they being apparently obscured -by clouds, in which were many luminous points, similar to what is often -experienced on rising suddenly and stretching out the arms, after -sitting long in one position.</p> - -<p>I felt myself totally incapable of speaking, and for some time lost all -consciousness of where I was, or who was near me. My whole frame felt -as if violently agitated: I thought I panted violently: my heart seemed -to palpitate, and every artery to throb with violence; I felt a singing -in my ears; all the vital motions seemed to be irresistibly hurried on, -as if their equilibrium had been destroyed, and every thing was running -headlong into confusion. My ideas succeeded one another with extreme -rapidity, thoughts rushed like a torrent through my mind, as if their -<span class="pagenum" id="Page_511">[Pg 511]</span> -velocity had been suddenly accelerated by the bursting of a barrier -which had before retained them in their natural and equable course. -This state of extreme hurry, agitation, and tumult, was but transient. -Every unnatural sensation gradually subsided; and in about a quarter of -an hour after I had ceased to breathe the gas, I was nearly in the same -state in which I had been at the commencement of the experiment.</p> - -<p>I cannot remember that I experienced the least pleasure from any of -these sensations. I can however, easily conceive, that by frequent -repetition I might reconcile myself to them, and possibly even receive -pleasure from the same sensations which were then unpleasant.</p> - -<p>I am sensible that the account I have been able to give of my feelings -is very imperfect. For however calculated their violence and novelty -were to leave a lasting impression on the memory, these circumstances -were for that very reason unfavourable to accuracy of comparison with -sensations already familiar. -<span class="pagenum" id="Page_512">[Pg 512]</span></p> - -<p>The nature of the sensations themselves, which bore greater resemblance -to a half delirious dream than to any distinct state of mind capable -of being accurately remembered, contributes very much to increase the -difficulty. And as it is above two months since I made the experiment, -many of the minuter circumstances have probably escaped me.</p> - -<p class="author">I remain,<span class="ws3"> </span><br /> -Yours, &c.  <br /> - -<span class="smcap">P. Roget.</span></p> - -<p>To <span class="smcap">Mr. Davy</span>.</p> - -<hr class="chap x-ebookmaker-drop" /> - -<p id="RIV_DII_06" class="f120 space-above1">VI. <i>Letter from</i> -<span class="smcap">Mr. James Thomson</span>.</p> - -<p>The first time I respired nitrous oxide, the experiment was made -under a strong impression of fear, and the quantity I breathed not -sufficient, as you informed me, to produce the usual effect. I did not -note very accurately my sensations. I remember I experienced a slight -degree of vertigo after the third or fourth inspiration; and breathed -with increased vigor, my inspirations being much deeper and more -<span class="pagenum" id="Page_513">[Pg 513]</span> -vehement than ordinary. I was enabled the next time I made the -experiment, to attend more accurately to my sensations, and you have -the observations I made on them at the time.</p> - -<p>After the fourth inspiration, I experienced the same increased action -of the lungs, as in the former case. My inspirations became uncommonly -full and strong, attended with a thrilling sensation about the chest, -highly pleasurable, which increased to such a degree as to induce a fit -of involuntary laughter, which I in vain endeavoured to repress. I felt -a slight giddiness which lasted for a few moments only. My inspirations -now became more vehement and frequent; and I inhaled the air with an -avidity strongly indicative of the pleasure I received. That peculiar -thrill which I had at first experienced at the chest, now pervaded -my whole frame; and during the two or three last inspirations, was -attended with a remarkable tingling in my fingers and toes. My feelings -at this moment are not to be described: I felt a high, an extraordinary -<span class="pagenum" id="Page_514">[Pg 514]</span> -degree of pleasure, different from that produced by wine, being -divested of all its gross accompaniments, and yet approaching nearer to -it than to any other sensation I am acquainted with.</p> - -<p>I am certain that my muscular strength was for a time much increased. -My disposition to exert it was such as I could not repress, and the -satisfaction I felt in any violent exertion of my legs and arms is -hardly to be conceived. These vivid sensations were not of long -duration; they diminished insensibly, and in little more than a quarter -of an hour I could perceive no difference between the state I was then -in, and that previous to the respiration of the air.</p> - -<p>The observations I made on repeating the experiment, do not differ from -the preceding, except in the circumstance of the involuntary laughter, -which I never afterwards experienced, though I breathed the air several -times; and in the following curious fact, which, as it was dependent on -circumstances, did not always occur.</p> - -<p>Having respired the same quantity of air as usual, and with precisely -<span class="pagenum" id="Page_515">[Pg 515]</span> -the same effects, I was surprised to find myself affected a few minutes -afterwards with the recurrence of a pain in my back and knees, which I -had experienced the preceding day from fatigue in walking. I was rather -inclined to deem this an accidental coincidence than an effect of the -air; but the same thing constantly occurring whenever I breathed the -air, shortly after suffering pain either from fatigue, or any other -accidental cause, left no doubt on my mind as to the accuracy of the -observation.</p> - -<p>I have now given you the substance of the notes I made whilst the -impressions were strong on my mind. I cannot add any thing from -recollection that will at all add to the accuracy of this account, or -assist those who have not respired this air, in forming a clearer idea -of its extraordinary effects. It is extremely difficult to convey to -others by means of words, any idea of particular sensations, of which -they have had no experience. It can only be done by making use of such -terms as are expressive of sensations that resemble them, and in these -<span class="pagenum" id="Page_516">[Pg 516]</span> -our vocabulary is very defective. To be able at all to comprehend -the effects of nitrous oxide, it is necessary to respire it, and -after that, we must either invent new terms to express these new and -particular sensations, or attach new ideas to old ones, before we can -communicate intelligibly with each other on the operation of this -extraordinary gas.</p> - -<p class="author">I am &c.<span class="ws5"> </span><br /><span class="smcap">James Thomson.</span></p> -<p><i>London, Sept. 21, 1799.</i></p> -<p>To <span class="smcap">Mr. Davy</span>.</p> - -<hr class="chap x-ebookmaker-drop" /> - -<p id="RIV_DII_07" class="f120 space-above1">VII. <i>Detail of</i> -<span class="smcap">Mr. Coleridge</span>.</p> - -<p>The first time I inspired the nitrous oxide, I felt an highly -pleasurable sensation of warmth over my whole frame, resembling that -which I remember once to have experienced after returning from a walk -in the snow into a warm room. The only motion which I felt inclined to -make, was that of laughing at those who were looking at me. My eyes -<span class="pagenum" id="Page_517">[Pg 517]</span> -felt distended, and towards the last, my heart beat as if it were -leaping up and down. On removing the mouth-piece the whole sensation -went off almost instantly.</p> - -<p>The second time, I felt the same pleasurable sensation of warmth, but -not I think, in quite so great a degree. I wished to know what effect -it would have on my impressions; I fixed my eye on some trees in the -distance, but I did not find any other effect except that they became -dimmer and dimmer, and looked at last as if I had seen them through -tears. My heart beat more violently than the first time. This was after -a hearty dinner.</p> - -<p>The third time I was more violently acted on than in the two former. -Towards the last, I could not avoid, nor indeed felt any wish to avoid, -beating the ground with my feet; and after the mouth-piece was removed, -I remained for a few seconds motionless, in great extacy.</p> - -<p>The fourth time was immediately after breakfast. The few first -inspirations affected me so little that I thought Mr. Davy had given me -<span class="pagenum" id="Page_518">[Pg 518]</span> -atmospheric air: but soon felt the warmth beginning about my chest, and -spreading upward and downward, so that I could feel its progress over -my whole frame. My heart did not beat so violently; my sensations were -highly pleasurable, not so intense or apparently local, but of more -unmingled pleasure than I had ever before experienced.<a id="FNanchor_225" href="#Footnote_225" class="fnanchor">[225]</a></p> - -<p class="author"><span class="smcap">S. T. Coleridge.</span></p> - -<hr class="chap x-ebookmaker-drop" /> - -<p id="RIV_DII_08" class="f120 space-above1">VIII. <i>Detail of</i> -<span class="smcap">Mr. Wedgwood</span>.</p> - -<p>July 23, I called on Mr. Davy at the Medical Institution, who asked -me to breathe some of the nitrous oxide, to which I consented, being -rather a sceptic as to its effects, never having seen any person -affected. I first breathed about six quarts of air which proved to be -only common atmospheric air, and which consequently produced no effect. -<span class="pagenum" id="Page_519">[Pg 519]</span></p> - -<p>I then had 6 quarts of the oxide given me in a bag undiluted, and -as soon as I had breathed three or four respirations, I felt myself -affected and my respiration hurried, which effect increased rapidly -until I became as it were entranced, when I threw the bag from me and -kept breathing on furiously with an open mouth and holding my nose -with my left hand, having no power to take it away though aware of -the ridiculousness of my situation. Though apparently deprived of all -voluntary motion, I was sensible of all that passed, and heard every -thing that was said; but the most singular sensation I had, I feel it -impossible accurately to describe. It was as if all the muscles of the -body were put into a violent vibratory motion; I had a very strong -inclination to make odd antic motions with my hands and feet. When the -first strong sensations went off, I felt as if I were lighter than the -atmosphere, and as if I was going to mount to the top of the room. I -had a metallic taste left in my mouth, which soon went off.</p> - -<p>Before I breathed the air, I felt a good deal fatigued from a very long -<span class="pagenum" id="Page_520">[Pg 520]</span> -ride I had had the day before, but after breathing, I lost all sense of fatigue.</p> - -<hr class="chap x-ebookmaker-drop" /> -<p id="RIV_DII_09" class="f120 space-above1">IX. <i>Detail of</i> -<span class="smcap">Mr. George Burnet</span>.</p> - -<p>I had never heard of the effects of the nitrous oxide, when I breathed -six quarts of it. I felt a delicious tremor of nerve, which was -rapidly propagated over the whole nervous system. As the action of -inhaling proceeds, an irresistible <i>appetite</i> to repeat it is -excited. There is now a general swell of sensations, vivid, strong, -and inconceivably pleasurable. They still become more vigorous and -glowing till they are communicated to the brain, when an ardent flush -overspreads the face. At this moment the tube inserted in the air-bag -was taken from my mouth, or I must have fainted in extacy.</p> - -<p>The operation being over, the strength and turbulence of my sensations -subsided. To this succeeded a state of feeling uncommonly serene and -<span class="pagenum" id="Page_521">[Pg 521]</span> -tranquil. Every nerve being gently agitated with a lively enjoyment. -It was natural to expect that the effect of this experiment, would -eventually prove debilitating. So far from this I continued in a state -of high excitement the remainder of the day after two o’clock, the -time of the experiment, and experienced a flow of spirits not merely -chearful, but unusually joyous.</p> - -<p class="author"><span class="smcap">George Burnet.</span></p> - -<hr class="chap x-ebookmaker-drop" /> -<p id="RIV_DII_10" class="f120 space-above1">X. <i>Detail of</i> -<span class="smcap">Mr. T. Pople</span>.</p> - -<p>A disagreeable sensation as if breaking out into a profuse -perspiration, tension of the tympanum, cheeks and forehead; almost -total loss of muscular power; afterwards increased powers both of -body and mind, very vivid sensations and highly pleasurable. Those -pleasant feelings were not new, they were felt, but in a less degree, -on ascending some high mountains in Glamorganshire.</p> - -<p>On taking it the second time, there was a disagreeable feeling about -<span class="pagenum" id="Page_522">[Pg 522]</span> -the face. In a fewseconds, the feelings became pleasurable; all the -faculties absorbed by the fine pleasing feelings of existence without -consciousness; an involuntary burst of laughter.</p> - -<p class="author"><span class="smcap">Thomas Pople.</span></p> - -<hr class="chap x-ebookmaker-drop" /> -<p id="RIV_DII_11" class="f120 space-above1">XI. <i>Detail of</i> -<span class="smcap">Mr. Hammick</span>.</p> - -<p>Having never heard any thing of the mode of operation of nitrous oxide, -I breathed gas in a silk bag for some time, and found no effects, but -oppression of respiration. Afterwards Mr. Davy told me that I had been -breathing atmospheric air.</p> - -<p>In a second experiment made without knowing what gas was in the bag, I -had not breathed half a minute, when from the extreme pleasure I felt, -I unconciously removed the bag from my mouth; but when Mr. Davy offered -to take it from me, I refused to let him have it, and said eagerly, -“let me breathe it again, it is highly pleasant! it is the strongest -<span class="pagenum" id="Page_523">[Pg 523]</span> -stimulant I ever felt!“ I was cold when I began to respire, but had -immediately a pleasant glow extending to my toes and fingers. I -experienced from the air a pleasant taste which I can only call sweetly -astringent; it continued for some time: the sense of exhilaration was -lasting. This air Mr. Davy told me was nitrous oxide.</p> - -<p>In another experiment, when I breathed a small dose of nitrous oxide, -the effects were slight, and sometime afterwards I felt an unusual -yawning and languor.</p> - -<p>The last time that I breathed the gas, the feelings were the most -pleasurable I ever experienced; my head appeared light, there was a -great warmth in the back and a general unusual glow; the taste was -distinguishable for some time as in the former experiment. My ideas -were more vivid, and followed the natural order of association. I could -not refrain from muscular action.</p> - -<p class="author"><span class="smcap">Stephen Hammick</span>, Junr.</p> -<p><i>Sept. 15th.</i> -<span class="pagenum" id="Page_524">[Pg 524]</span></p> - -<hr class="chap x-ebookmaker-drop" /> -<p id="RIV_DII_12" class="f120 space-above1">XII. <i>Detail of</i> -<span class="smcap">Dr. Blake</span>.</p> - -<p>Dr. Blake inhaled about six quarts of the air, was affected during -the process of respiring it with a slight degree of vertigo, which -was almost immediately succeeded by a thrilling sensation extending -even to the extremities, accompanied by a most happy state of mind and -highly pleasurable ideas. He felt a great propensity to laugh, and -his behaviour in some measure appeared ludicrous to those around him. -Muscular power seemed agreeably increased, the pulse acquired strength -and firmness, but its frequency was somewhat diminished. He perceived -rather an unpleasant taste in the mouth and about the fauces for -some hours afterwards, but in every other respect, his feelings were -comfortable during the remainder of the day.</p> - -<p><i>December, 30th.</i></p> -<p>To <span class="smcap">Mr. Davy</span>. -<span class="pagenum" id="Page_525">[Pg 525]</span></p> - -<hr class="chap x-ebookmaker-drop" /> -<p id="RIV_DII_13" class="f120 space-above1">XIII. <i>Detail of</i> -<span class="smcap">Mr. Wansey</span>.</p> - -<p>I breathed the gas out of a silk bag, believing it to be nitrous oxide, -and was much surprised to find that it produced no sensations. After -the experiment, Mr. Davy told me it was common air.</p> - -<p>I then breathed a mixture of common air and nitrous oxide. I felt a -kind of intoxication in the middle of the experiment, and stopping to -express this, destroyed any farther effects.</p> - -<p>I now breathed pure nitrous oxide; the effect was gradual, and I at -first experienced fulness in the head, and afterwards sensations so -delightful, that I can compare them to no others, except those which -I felt (being a lover of music) about five years since in Westminster -Abbey, in some of the grand choruses in the Messiah, from the united -<span class="pagenum" id="Page_526">[Pg 526]</span> -powers of 700 instruments of music. I continued exhilarated throughout -the day, slept at night remarkably sound, and experienced when I awoke -in the morning, a recurrence of pleasing sensation.</p> - -<p>In another experiment, the effects was still greater, the pulse was -rendered fuller and quicker, I felt a sense of throbbing in the head -with highly pleasurable thrillings all over the frame. The new feelings -were at last so powerful as to absorb all perception. I distinguished -during and after the experiment, a taste on the tongue, like that -produced by the contact of zinc and silver.</p> - -<p class="author"><span class="smcap">Henry Wansey.</span></p> - -<hr class="chap x-ebookmaker-drop" /> -<p id="RIV_DII_14" class="f120 space-above1">XIV. <i>Detail of</i> -<span class="smcap">Mr. Rickman</span>.</p> - -<p>On inhaling about six quarts, the first altered feeling was a tingling -in the elbows not unlike the effect of a slight electric shock. Soon -afterwards, an involuntary and provoking dizziness as in drunkenness. -Towards the close of the inhalation, this symptom decreased; though the -<span class="pagenum" id="Page_527">[Pg 527]</span> -nose was still involuntary held fast after the air-bag was removed. The -dose was probably an undercharge, as no extraordinary sensation was -felt more than half a minute after the inhalation.</p> - -<p class="author"><span class="smcap">J. Rickman.</span></p> - -<hr class="chap x-ebookmaker-drop" /> -<p id="RIV_DII_15" class="f120 space-above1">XV. <i>Detail of</i> -<span class="smcap">Mr. Lovell Edgworth</span>.</p> - -<p>My first sensation was an universal and considerable tremor. I then -perceived some giddiness in my head, and a violent dizziness in my -sight; those sensations by degrees subsided, and I felt a great -propensity to bite through the wooden mouth-piece, or the tube of the -bag through which I inspired the air. After I had breathed all the air -that was in the bag, I eagerly wished for more. I then felt a strong -propensity to laugh, and did burst into a violent fit of laughter, and -capered about the room without having the power of restraining myself. -By degrees these feelings subsided, except the tremor which lasted -for an hour after I had breathed the air, and I felt a weakness in my -knees. The principal feeling through the whole of the time, or what I -<span class="pagenum" id="Page_528">[Pg 528]</span> -should call the characteristical part of the effect, was a total -difficulty of restraining my feelings, both corporeal and mental, or in -other words, not having any command of one’self.</p> - -<hr class="chap x-ebookmaker-drop" /> -<p id="RIV_DII_16" class="f120 space-above1">XVI. <i>Detail of</i> -<span class="smcap">Mr. G. Bedford</span>.</p> - -<p>I inhaled 6 quarts. Experienced a sensation of fulness in the -extremities and in the face, with a desire and power of expansion of -the lungs very pleasurable. Feelings similar to intoxication were -produced, without being disagreeable. When the bag was taken away, an -involuntary though agreeable laughter took place, and the extremities -were warm.</p> - -<p>In about a quarter of an hour after the above experiment, I inhaled 8 -quarts. The warmth and fulness of the face and extremities were sooner -produced during the inspiration. The candle and the persons about me, -assumed the same appearances as took place during the effect produced -<span class="pagenum" id="Page_529">[Pg 529]</span> -by wine, and I could perceive no determinate outline. The desire and -power to expand the lungs was increased beyond that in the former -experiment, and the whole body and limbs seemed dilated without -the sense of tension, it was as if the bulk was increased without -any addition to the specific gravity of the body, which was highly -pleasant. The provocation to laughter was not so great as in the former -experiment, and when the bag was removed, the warmth almost suddenly -gave place to a coldness of the extremities, particularly of the hands -which were the first to become warm during the inspiration. A slight -sensation of fulness not amounting to pain in the head, has continued -for some minutes. After the first experiment, a sensation in the wrists -and elbows took place, similar to that produced by the electric shock.</p> - -<p class="author"><span class="smcap">G. C. Bedford.</span></p> -<p><i>March 30th, 1800.</i> -<span class="pagenum" id="Page_530">[Pg 530]</span></p> - -<hr class="chap x-ebookmaker-drop" /> -<p id="RIV_DII_17" class="f120 space-above1">XVII. <i>Detail of</i> -<span class="smcap">Miss Ryland</span>.</p> - -<p>After having breathed five quarts of gas, I experienced for a short -time a quickness and difficulty of breathing, which was succeeded by -extreme languor, resembling fainting, without the very unpleasant -sensation with which it is usually attended. It entirely deprived me of -the power of speaking, but not of recollection, for I heard every thing -that was said in the room during the time; and Mr. Davy’s remark “that -my pulse was very quick and full.“ When the languor began to subside, -it was succeeded by restlessness, accompanied by involuntary muscular -motions. I was warmer than usual, and very sleepy for several hours.</p> - -<hr class="chap x-ebookmaker-drop" /> -<p id="RIV_DII_18" class="f120 space-above1">XVIII. <i>Letter from</i> -<span class="smcap">Mr. M. M. Coates</span>.</p> - -<p>I will, as you request, endeavour to describe to you the effect -produced on me last Sunday fe’nnight by the nitrous oxide, and will at -<span class="pagenum" id="Page_531">[Pg 531]</span> -the same time tell you what was the previous state of my mind on the subject.</p> - -<p>When I sat down to breathe the gas, I believed that it owed much of -its effect to the predisposing agency of the imagination, and had no -expectation of its sensible influence on myself. Having ignorantly -breathed a bag of common air without any effect, my doubts then arose -to positive unbelief.</p> - -<p>After a few inspirations of the nitrous oxide, I felt a fulness in -my head, which increased with each inhalation, until, experiencing -symptoms which I thought indicated approaching fainting, I ceased to -breathe it, and was then confirmed in my belief of its inability to -produce in me any pleasurable sensation.</p> - -<p>But after a few seconds, I felt an immoderate flow of spirits, and an -irresistible propensity to violent laughter and dancing, which, being -fully conscious of the violence of my feelings, and of their irrational -exhibition, I made great but ineffectual efforts to restrain; this was -<span class="pagenum" id="Page_532">[Pg 532]</span> -my state for several minutes. During the rest of the day, I experienced -a degree of hilarity altogether new to me. For six or seven days -afterwards, I seemed to feel most exquisitely at every nerve, and was -much indisposed to my sedentary pursuits; this acute sensibility has -been gradually diminishing; but I still feel somewhat of the effects of -this novel agent.</p> - -<p class="author">Your’s truly,<span class="ws2"> </span><br /> -<span class="smcap">M. M. Coates</span>.</p> - -<p>To Mr. <span class="smcap">Davy</span>.<br /> -<span class="ws2"> </span><i>June 11th, 1800.</i> -<span class="pagenum" id="Page_533">[Pg 533]</span></p> -</div> - -<hr class="chap x-ebookmaker-drop" /> -<h3 id="RIV_DIV_III">DIVISION III.</h3> - -<p class="neg-indent space-below1"><i>ABSTRACTS from ADDITIONAL DETAILS.—OBSERVATIONS -on the EFFECTS of NITROUS OXIDE, by Dr. BEDDOES.—CONCLUSION.</i></p> - -<p id="RIV_DIII_01" class="f120">I. <i>Abstracts from additional Details.</i></p> - -<p>The trials related in the following abstracts, have been chiefly made -since the publication of Dr. Beddoes’s Notice. Many of the individuals -breathed the gas from pure curiosity. Others with a disbelief of its powers.</p> - -<hr class="tb" /> - -<p>Mr. <span class="smcap">Wynne</span>, M. P. breathed five quarts of diluted nitrous -oxide, without any sensation. Six quarts produced fulness in the chest, -heat in the hands and feet, and sense of tension in the fingers, slight -but pleasant sensations. Seven quarts produced no new or different effects. -<span class="pagenum" id="Page_534">[Pg 534]</span></p> - -<p>Mr. <span class="smcap">Mackintosh</span> several times breathed nitrous oxide. He had -sense of fulness in the head, thrillings, tingling in the fingers, and -generally pleasurable feelings.</p> - -<p>Mr. <span class="smcap">John Cave</span>, Junr. from breathing four quarts of nitrous -oxide, felt sensations as from superior wine, and general pleasant -feelings.</p> - -<p>Mr. <span class="smcap">Michael Castle</span>, from five quarts, experienced sensations -of heat and thrilling, general spirits heightened considerably as from -wine; afterwards, slight pain in the back of the head.</p> - -<p>Mr. <span class="smcap">H. Cardwell</span>, from five quarts, had feelings so pleasurable -as almost to destroy consciousness; almost convulsed with laughter; for -a long time could not think of the feeling without laughing; sensation -of lightness for some time after.</p> - -<p>Mr. <span class="smcap">Jarman</span>, from five quarts, great pleasure, laughter, -certainly better spirits, glow in the cheeks which continued long. -<span class="pagenum" id="Page_535">[Pg 535]</span></p> - -<p>The gentleman who furnished the preceding detail, had heard of -the effects of nitrous oxide, and was prepared to experience new -sensations: I therefore gave him a bag of common air which he respired, -believing it to be nitrous oxide; and was much surprised that no -effects were produced. He then breathed five quarts of nitrous oxide, -and after the experiment, gave this account of his sensations.</p> - -<p>Rev. <span class="smcap">W. A. Cane</span>, after inhaling the gas, felt -the most delicious sensations accompanied by a thrill through every part of -his body. He did not think it possible so charming an effect could -have been produced. He had heard of the gas; but the result of the -experiment far exceeded his expectations.</p> - -<p><i>May 6th</i>, 1800.</p> - -<hr class="tb" /> - -<p>Mr. <span class="smcap">Joseph Priestley</span> from breathing nitrous oxide, generally -had unpleasant fulness of the head and throbbing of the arteries, which -prevented him from continuing the respiration. -<span class="pagenum" id="Page_536">[Pg 536]</span></p> - -<p>Dr. <span class="smcap">Beddoes</span> mentioned in his Notice, that Mr. <span class="smcap">Josiah -Wedgwood</span> and Mr. <span class="smcap">Thomas Wedgwood</span> experienced rather -unpleasant feelings from the gas. Mr. <span class="smcap">Josiah Wedgwood</span> has -since repeated the trial, the effects were powerful, but not in the -slighted degree pleasant.</p> - -<p>Mr. <span class="smcap">R. Boulton</span> and Mr. <span class="smcap">G. Watt</span> -have been much less affected than any individuals.</p> - -<p>Many other persons have respired the gas, but as their accounts contain -nothing unnoticed in the details, it is useless to particularise them.</p> - -<p>The cases of all the males who have been unpleasantly affected since -we have learnt to prepare the gas with accuracy, are related in this -Section and in the last <a href="#RIV_DIV_I">Division</a>. Those who -have been pleasurably affected after a fair trial and whose cases are -not noticed, generally experienced fulness in the head, heat in the -chest, pleasurable thrillings, and consequent exhilaration.</p> - -<p>To persons who have been unaccustomed to breathe through a tube, we -have usually given common air till they have learnt to respire with -<span class="pagenum" id="Page_537">[Pg 537]</span> -accuracy: and in cases where the form of the mouth has prevented the -lips from being accurately closed on the breathing tube, by the advice -of Mr. Watt, we have used a tin plate conical mouth-piece fixed to the -cheeks, and accurately adapted to the lips; by means of which -precautions, all our later trials have been perfectly conclusive.</p> - -<p id="RIV_DIII_02" class="f120 space-above1">II. <i>Of the effects of -Nitrous Oxide upon persons<br /> inclined to hysterical and nervous affections.</i></p> - -<p>The case of Miss—— N. and other cases, detailed by Dr. Beddoes -in his Notice, seemed to prove that the action of nitrous oxide was -capable of producing hysterical and nervous affections in delicate and -irritable constitutions.</p> - -<p>On this subject, we have lately acquired additional facts.</p> - -<p>Miss E. a young lady who had been subject to hysteric fits, breathed -three quarts of nitrous oxide mingled with much common air, and felt no -<span class="pagenum" id="Page_538">[Pg 538]</span> -effects but a slight tendency to fainting. She then breathed four -quarts of pure nitrous oxide: her first inspirations were deep, her -last very feeble. At the end she dropt the bag from her lips, and -continued for some moments motionless. Her pulse which at the beginning -of the experiment was strong, appeared to me to be at this time, -quicker and weaker. She soon began to move her hands and talked for -some minutes incoherently, as if ignorant of what had passed. In less -than a quarter of an hour, she had recovered, but could give no account -of her sensations. A certain degree of languor continued through the day.</p> - -<p>A young lady who never had hysterical attacks, wished to breathe the -gas. I informed her of the disagreeable effects it had sometimes -produced, and advised her if she had the slightest tendency to nervous -affection, not to make the trial. She persisted in her resolution. -<span class="pagenum" id="Page_539">[Pg 539]</span></p> - -<p>To ascertain the influence of imagination, I first gave her a bag of -common air, which she declared produced no effect. I then ordered for -her a quart of nitrous oxide mingled with two quarts of common air; but -from the mistake of the person who prepared it, three quarts of nitrous -oxide were administered with one of common air. She breathed this for -near a minute, and after the experiment, described her sensations as -unpleasant, and said she felt at the moment as if she was dying. The -unpleasant feelings quickly went off, and a few minutes after, she had -apparently recovered her former state of mind. In the course of the -day, however, a violent head-ache came on, and in the evening after she -had taken a medicine which operated violently, hysterical affections -were produced, followed by great debility. They occasionally returned -for many days, and the continued weak and debilitated for a great -length of time.</p> - -<p>Mrs. S. a delicate lady, liable to nervous affections who had heard of -<span class="pagenum" id="Page_540">[Pg 540]</span> -the cases just detailed, chose to breathe the gas. By three quarts she -was thrown into a trance, which lasted for three or four minutes. On -recovering, the could give no account of her feelings, and had some -languor for half an hour afterwards.</p> - -<p>These phænomena have rendered us cautious in administering the gas to -delicate females. In a few instances however, it has been taken by -persons of this class, and even by those inclined to hysterical and -nervous complaints with pleasurable effects.</p> - -<p>Miss L. a young lady who had formerly had hysterical fits, breathed a -quart of nitrous oxide with three quarts of common air without effects. -Two quarts of nitrous oxide with one of common air produced a slight -giddiness; four quarts of nitrous oxide produced a fit of immoderate -laughter, which was succeeded by slight exhilaration, her spirits were -good throughout the day, and no depression followed. -<span class="pagenum" id="Page_541">[Pg 541]</span></p> - -<p>Miss B. Y—— and Miss S. Y—— both delicate but healthy young -ladies, were affected very pleasantly; each by three quarts of nitrous oxide, -the first time of respiring it. Miss B Y—— continued exhilarated and -in high spirits for some hours after the dose. Miss S. Y—— had a -slight head-ache, which did not go off for some hours.</p> - -<p>Mrs. F. inclined to be hysterical, breathed four quarts of nitrous -oxide mingled with common air. She was giddy and described her feelings -as odd; but had not the slightest languor after the experiment.</p> - -<p id="RIV_DIII_03" class="f120 space-above1">III. <i>Observations on -the effects of Nitrous Oxide,<br /> by</i> <span class="smcap">Dr. Beddoes</span>.</p> - -<p>Neither my notes nor my recollection supply much in addition to what -I formerly stated in the <i>Notice of Observations at the Pneumatic -Institution</i>. <i>Longman.</i> The gas maintains its first character -<span class="pagenum" id="Page_542">[Pg 542]</span> -as well in its effects on me, as in the benefit it confers on some of -the paralytic, and the injury it does or threatens to the hysterical -and the exquisitely sensible. I find that five or six quarts operate -as powerfully as ever. I seem to make a given quantity go farther by -holding my breath so that the gas may be absorbed in a great degree -without returning into the bag, and therefore, be as little heated -before inspiration as possible.—This may be fancy.</p> - -<p>After innumerable trials, I have never once felt lassitude or -<span class="pagenum" id="Page_543">[Pg 543]</span> -depression<a id="FNanchor_226" href="#Footnote_226" class="fnanchor">[226]</a>. -Most commonly I am sensible of a grateful glow <i>circum -præcordia</i>. This has continued for hours.—In two or three instances -only has inhalation failed to be followed by pleasurable feeling, it -has never been followed by the contrary. On a few occasions before the -gas was exhausted, I have found it impossible to continue breathing.</p> - -<p>The pulse at first becomes fuller and stronger. Whenever, after -exposure to a cold wind, the warmth of the room has created a glow in -the cheeks, the gas has increased this to strong flushing—which common -air breathed in the same way, failed to do.</p> - -<p>Several times I have found that a cut which had ceased to be painful -has smarted afresh, and on taking two doses in succession, the smarting -ceased in the interval and returned during the second respiration. I -had no previous expectation of the first smarting. -<span class="pagenum" id="Page_544">[Pg 544]</span></p> - -<p>The only time I was near rendering myself insensible to present -objects by very carefully breathing several doses in quick succession, -I forcibly exclaimed, <span class="allsmcap">TONES</span>!—In fact, besides -a general thrilling, there seemed to be quick and strong alterations in the -degree of illumination of all surrounding objects; and I felt as if -composed of finely vibrating strings. On this occasion, the skin seemed -in a state of constriction and the lips glued to the mouth-piece, -and the mucous membrane of the lungs contracted, but not painfully. -However, no constriction or corrugation of the skin could be seen. -I am conscious of having made a great number of observations while -breathing, which I could never recover.</p> - -<p>Immediately afterwards I have often caught myself walking with a -hurried step and busy in soliloquy. The condition of general sensation -being as while hearing chearful music, or after good news, or a -moderate quantity of wine.</p> - -<p>Mr. John Cave, Junr. and his three friends, as well as others, compared -<span class="pagenum" id="Page_545">[Pg 545]</span> -the effects to Champagne. Most persons have had the idea of the effect -of fermented liquors excited by the gas. It were to be wished that we -had, for a standard of comparison, observations on the effect of these -liquors as diversified and as accurate as we have obtained concerning -the gas; nor would more uniformity in the action of these substances be -observed if the enquiry were strictly pursued. Opium and spirits seem, -in particular states to sicken and distress in the first instance; how -differently does wine at an early hour and fasting act upon those who -are accustomed to take it only after dinner!</p> - -<p>I thought it might be an amusing spectacle to see the different tints -of blood flowing from a wound by a leech in consequence of breathing -different airs. The purple from the nitrous oxide was very evident. -Oxygene, we thought, occasioned a quicker flow and brighter color in -the blood. In another experiment, an inflamed area round the puncture -from a leech applied the day before, was judged by several spectators -<span class="pagenum" id="Page_546">[Pg 546]</span> -to become much more crimson on the respiration of about 20 quarts of -oxygene gas, which possibly acts more powerfully on inflamed parts.<a id="FNanchor_227" href="#Footnote_227" class="fnanchor">[227]</a> -These and many similar experiments, require to be repeated on the blood -of single arteries opened in warm and cold animals.</p> - -<p>It has appeared to me that I could hold my breath uncommonly long when -respiring oxygene gas mixed with nitrous oxide. While trying this -to-day, (17th June), I thought the sense of smell much more acute after -the nitrous oxide than before I began to respire at all; and then I -felt conscious that this increased acuteness had before repeatedly -<span class="pagenum" id="Page_547">[Pg 547]</span> -occurred—a fact very capable, I apprehend, of a pneumatological -interpretation.</p> - -<p>Time by my feelings has always appeared longer than by a watch.</p> - -<p>I thought of trying to observe whether while I alternately breathed -quantities of nitrous oxide and oxygene gas and common air, I could -observe any difference in the operation of a blister beginning to -bite the skin. It would be of consequence to ascertain the effect -of regulating by compression the flow of blood, while stimulants of -various kinds (and heated bodies among the rest) were applied to or -near the extremities—because in erisipelas and various inflammatory -affections, a ready and pleasant cure might be effected by partial -compression of the arteries going to the diseased part; and a great -improvement in practice thus obtained.</p> - -<p>But I should run into an endless digression, were I to enumerate -possible physiological experiments with artificial airs, or to -speculate on the mechanical improvement of medicine, which at present -<span class="pagenum" id="Page_548">[Pg 548]</span> -as far as mechanical means of affecting the living system are concerned, -is with us in a state that would almost disgrace a nation of savages.</p> - -<p id="RIV_DIII_04" class="f120 space-above1">IV. <span class="smcap">Conclusion.</span></p> - -<p>From the facts detailed in the preceding pages, it appears that -the immediate effects of nitrous oxide upon the living system, are -analogous to those of diffusible stimuli. Both increase the force of -circulation, produce pleasurable feeling, alter the condition of the -organs of sensation, and in their most extensive action destroy life.</p> - -<p>In the mode of operation of nitrous oxide and diffusible stimuli, -considerable differences however, exist.</p> - -<p>Diffusible stimuli act immediately on the muscular and nervous fibre. -Nitrous oxide operates upon them only by producing peculiar changes in -the composition of the blood. -<span class="pagenum" id="Page_549">[Pg 549]</span></p> - -<p>Diffusible stimuli affect that part of the system most powerfully to -which they are applied, and act on the whole only by means of its -sympathy with that part. Nitrous oxide in combination with the blood, -is universal in its application and action.</p> - -<p>We know very little of the nature of excitement; as however, life -depends immediately on certain changes effected in the blood in -respiration, and ultimately on the supply of certain nutritive matter -by the lymphatics; it is reasonable to conclude, that during the action -of simulating substances, from the increased force of circulation, not -only more oxygene and perhaps nitrogene must be combined with the blood -in respiration,<a id="FNanchor_228" href="#Footnote_228" class="fnanchor">[228]</a> -but likewise more fluid nutritive matter supplied to it in circulation. -<span class="pagenum" id="Page_550">[Pg 550]</span></p> - -<p>By this oxygene and nutritive matter excitability may be kept up: and -exhaustion consequent to excitement only produced, in consequence of a -deficiency of some of the nutritive principles, which are supplied by -absorption.</p> - -<p>When nitrous oxide is breathed, nitrogene (a principle under common -circumstances chiefly carried into the blood by the absorbents in fluid -compounds) is supplied in respiration; a greater quantity of oxygene -is combined with the blood than in common respiration, whilst less -carbonic acid and probably less water are evolved.</p> - -<p>Hence a smaller quantity of nutritive matter is probably required from -the absorbents during the excitement from nitrous oxide, than during -the operation of stimulants; and in consequence, exhaustion from the -expenditure of nutritive matter more seldom occasioned. -<span class="pagenum" id="Page_551">[Pg 551]</span></p> - -<p>Since <a href="#RES_III">Research III</a>. has been printed, I have -endeavoured to ascertain the quantities of nitrogene produced when -nitrous oxide is respired for a considerable time. In one experiment, -when I breathed about four quarts of gas in a glass bell over -impregnated water for near a minute, it was diminished to about two -quarts; and the residuum extinguished flame.</p> - -<p>Now the experiments in <a href="#RES_II">Research II</a>. prove that -when nitrous oxide is decomposed by combustible bodies, the quantity -of nitrogene evolved is rather greater in volume than the pre-existing -nitrous oxide. Hence much of the nitrogene taken into the system -during the respiration of nitrous oxide, must be either carried into -new combinations, or given out by the capillary vessels through the skin.</p> - -<p>It would be curious to ascertain whether the quantity of ammoniac in -the saline matters held in solution by the secreted fluids is increased -after the respiration of nitrous oxide. Experiments made upon the -<span class="pagenum" id="Page_552">[Pg 552]</span> -consumption of nitrous oxide mingled with atmospheric air by the -smaller animals, would go far to determine whether any nitrogene is -given out through the skin.</p> - -<p>The various effects of nitrous oxide upon different individuals and -upon the same individuals at different times, prove that its powers are -capable of being modified both by the peculiar condition of organs, and -by the state of general feeling.</p> - -<p>Reasoning from common phænomena of sensation, particularly those -relating to heat, it is probable that pleasurable feeling is uniformly -connected with a moderate increase of nervous action; and that this -increase when carried to certain limits, produces mixed emotion or -sublime pleasure; and beyond those limits occasions absolute pain.</p> - -<p>Comparing the facts in the last division, it is likely that individuals -possessed of high health and little sensibility, will generally be -less pleasurably affected by nitrous oxide than such as have more -sensibility, in whom the emotions will sometimes so far enter the limits -<span class="pagenum" id="Page_553">[Pg 553]</span> -of pain as to become sublime;<a id="FNanchor_229" href="#Footnote_229" class="fnanchor">[229]</a> -whilst the nervous action in such as have exquisite sensibility, will -be so much increased as often to produce disagreeable feeling.</p> - -<p>Modification of the powers of nitrous oxide by mixture of the gas -with oxygene or common air, will probably enable the most delicately -sensible to respire it without danger, and even with pleasurable -effects: heretofore it has been administered to such only in its pure -form or mingled with small quantities of atmospheric air, and in its -pure form even the most robust are unable to respire it with safety for -more than five minutes. -<span class="pagenum" id="Page_554">[Pg 554]</span></p> - -<p>The muscular actions<a id="FNanchor_230" href="#Footnote_230" class="fnanchor">[230]</a> -sometimes connected with the feelings produced by nitrous oxide, -seem to depend in a great measure upon the particular habits of the -individual; they will usually be of that kind which is produced either -by common pleasurable feelings or strong emotions.</p> - -<p>Hysterical affection is occasioned by nitrous oxide, probably only in -consequence of the strong emotion produced, which destroys the power of -the will, and calls up series of automatic motions formerly connected -with a variety of less powerful but similar feelings.</p> - -<p>The quickness of the operation of nitrous oxide, will probably render -it useful in cases of extreme debility produced by deficiency of common -<span class="pagenum" id="Page_555">[Pg 555]</span> -exciting powers. Perhaps it may be advantageously applied mingled with -oxygene or common air, to the recovery of persons apparently dead from -suffocation by drowning or hanging.</p> - -<p>The only diseases in which nitrous oxide has been hitherto employed, -are those of deficient sensibility.—An account of its agency in -paralytic affections, will be speedily published by Dr. Beddoes.</p> - -<p>As by its immediate operation the tone of the irritable fibre is -increased, and as exhaustion rarely follows the violent muscular -motions sometimes produced by it, it is not unreasonable to expect -advantages from it in cases of simple muscular debility.</p> - -<p>The apparent general transiency of its operation in the pure form -in single doses has been considered as offering arguments against -its power of producing lasting changes in the constitution. It will, -however, be easy to keep up excitement of different degrees of -intensity for a great length of time, either by administering the -<span class="pagenum" id="Page_556">[Pg 556]</span> -unmingled gas in rapid successive doses, or by preserving a permanent -atmosphere, containing different proportions of nitrous oxide and -common air, by means of a breathing chamber.<a id="FNanchor_231" href="#Footnote_231" class="fnanchor">[231]</a> -That single doses nevertheless, are capable of producing permanent -effects in some constitutions, is evident, as well from the hysterical -cases as from some of the details—particularly that of Mr. M. M. -Coates.</p> - -<p>As nitrous oxide in its extensive operation appears capable of -destroying physical pain, it may probably be used with advantage during -surgical operations in which no great effusion of blood takes place.</p> - -<p>From the strong inclination of those who have been pleasantly affected -by the gas to respire it again, it is evident, that the pleasure -produced, is not lost, but that it mingles with the mass of feelings, -and becomes intellectual pleasure, or hope. The desire of some -individuals acquainted with the pleasures of nitrous oxide for the gas -<span class="pagenum" id="Page_557">[Pg 557]</span> -has been often so strong as to induce them to breathe with eagerness, -the air remaining in the bags after the respiration of others.</p> - -<p>As hydrocarbonate acts as a sedative,<a id="FNanchor_232" href="#Footnote_232" class="fnanchor">[232]</a> -and diminishes living action as rapidly as nitrous oxide increases it, on the common theory of -excitability<a id="FNanchor_233" href="#Footnote_233" class="fnanchor">[233]</a> -it would follow, that by differently modifying the -atmosphere by means of this gas and nitrous oxide, we should be in -possession of a regular series of exciting and depressing<a id="FNanchor_234" href="#Footnote_234" class="fnanchor">[234]</a> -powers applicable to every deviation of the constitution from health: but -the common theory of excitability is most probably founded on a false -generalisation. The modifications of diseased action may be infinite -and specific in different organs; and hence out of the power of agents -operating on the whole of the system. -<span class="pagenum" id="Page_558">[Pg 558]</span></p> - -<p>Whenever we attempt to combine our scattered physiological facts, we -are stopped by the want of numerous intermediate analogies; and so -loosely connected or so independant of each other, are the different -series of phænomena, that we are rarely able to make probable -conjectures, much less certain predictions concerning the results of -new experiments.</p> - -<p>An immense mass of pneumatological, chemical, and medical information -must be collected, before we shall be able to operate with certainty, -on the human constitution. -<span class="pagenum" id="Page_559">[Pg 559]</span></p> - -<p>Pneumatic chemistry in its application to medicine, is an art in -infancy, weak, almost useless, but apparently possessed of capabilities -of improvement. To be rendered strong and mature, she must be nourished -by facts, strengthened by exercise, and cautiously directed in the -application of her powers by rational scepticism. -<span class="pagenum" id="Page_560">[Pg 560]</span></p> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_561">[Pg 561]</span></p> -<h2 class="nobreak">APPENDIX.</h2> -</div> - -<p id="APP_I" class="f120">No. I.</p> - -<p class="center"><i>Effects of Nitrous Oxide on Vegetation.</i></p> - -<p class="drop-cap"><span class="smcap">In</span> July 1799, I -introduced two small plants of spurge into nitrous oxide, in contact -with a little water over mercury; after remaining in it two days, they -preserved their healthy appearance, and I could not perceive that any -gas had been absorbed. I was prevented by an accident, from keeping -them longer in the gas.</p> - -<p>A small plant of mint introduced into nitrous oxide and exposed to -light, in three days became dark olive and spotted with brown; and in -about six days was quite dead.—Another similar plant, kept in the dark -<span class="pagenum" id="Page_562">[Pg 562]</span> -in nitrous oxide, did not alter in color for five days, and at the end -of seven days, was only a little yellower than before. I could not -ascertain whether any gas had been absorbed.</p> - -<p>I introduced into nitrous oxide through water, a healthy budding rose, -thinking that its colors might be rendered brighter by the gas. I was -disappointed, it very speedily faded and died; possibly injured by the -solution of nitrous oxide in water.</p> - -<p>Of two rows of peas just appearing above ground; I watered one with -solution of nitrous oxide in water, and the other with common water -daily, for a fortnight. At the end of this time, I could perceive no -difference in their growth, and afterwards they continued to grow -equally fast.</p> - -<p>I introduced through water into six phials, one of which contained -hydrogene, one oxygene, one common air, one hydrocarbonate, one -carbonic acid, and one nitrous oxide, six similar plants of mint, their -<span class="pagenum" id="Page_563">[Pg 563]</span> -roots being in contact with water and their leaves exposed to light.</p> - -<p>The plant in carbonic acid began to fade in less than two days, and -in four was dead. That in hydrogene died in less than five days; that -in nitrous oxide did not fade much for the first two days, but on -the third, drooped very much, and was dead at the same time as that -in hydrogene. The plant in oxygene for the first four days, looked -flourishing and was certainly of a finer green than before, gradually -however, its leaves became spotted with black and dropped off one by -one, till at the end of ten days they had all disappeared. At this -time the plant in common air looked sickly and yellow, whilst that in -hydrocarbonate was greener and more flourishing than ever.</p> - -<p>I have detailed these experiments not on account of any important -conclusions that may be drawn from them; but with a view of inducing -others to repeat them, and to examine the changes effected in the -<span class="pagenum" id="Page_564">[Pg 564]</span> -gases. If it should be found by future experiments, that hydrocarbonate -generally increased vegetation, it would throw some light upon the use -of manures, containing putrefying animal and vegetable substances, from -which this gas is perpetually evolved.</p> - -<p>The chemistry of vegetation though immediately connected with -agriculture, the art on which we depend for subsistence, has been but -little investigated. The discoveries of Priestley and Ingenhousz, seem -to prove that it is within the reach of our instruments of experiment. -<span class="pagenum" id="Page_565">[Pg 565]</span></p> - -<p id="APP_II" class="f120 space-above1">No. II.</p> - -<p class="center">APPROXIMATIONS TO THE<br /> <i>Composition and Weight of the aëriform</i></p> - -<p class="center"><i>COMBINATIONS of NITROGENE</i></p> - -<p class="center">At temperature 55°, and atmospheric pressure 30.</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" rules="cols" > - <thead><tr> - <th class="tdc bb2" colspan="8"> </th> - </tr><tr> - <th class="tdc"><span class="ws3"> </span></th> - <th class="tdc"> </th> - <th class="tdc bb"> 100 Cubic In. </th> - <th class="tdc bb"><span class="ws2"> </span></th> - <th class="tdc bb"> grains </th> - <th class="tdc"> </th> - <th class="tdc bb"> Nitrogene </th> - <th class="tdc bb"> Oxygene </th> - </tr> - </thead> - <tbody><tr> - <td class="tdc">N</td> - <td class="tdc bb" rowspan="7">With<br />oxygene</td> - <td class="tdl_ws1">Nitrogene</td> - <td class="tdc"> </td> - <td class="tdc">30.04</td> - <td class="tdc" rowspan="9">100<br />grains<br />are<br /> composed <br />of</td> - <td class="tdc"> </td> - <td class="tdc"> </td> - </tr><tr> - <td class="tdc">i</td> - <td class="tdl_ws1 bb">Oxygene</td> - <td class="tdc bb"> </td> - <td class="tdc bb">35.06</td> - <td class="tdc bb"> </td> - <td class="tdc bb"> </td> - </tr><tr> - <td class="tdc">t</td> - <td class="tdl_ws1">Atmospher. air </td> - <td class="tdc">w</td> - <td class="tdc">31.10</td> - <td class="tdc">73.00</td> - <td class="tdc">27.00</td> - </tr><tr> - <td class="tdc">r</td> - <td class="tdl_ws1">Nitrous oxide</td> - <td class="tdc">e</td> - <td class="tdc">50.20</td> - <td class="tdc">63.30</td> - <td class="tdc">36.70</td> - </tr><tr> - <td class="tdc">o</td> - <td class="tdl_ws1">Nitrous gas</td> - <td class="tdc">i</td> - <td class="tdc">34.26</td> - <td class="tdc">44.05</td> - <td class="tdc">55.95</td> - </tr><tr> - <td class="tdc">g</td> - <td class="tdl_ws1">Nitric acid</td> - <td class="tdc">g</td> - <td class="tdc">76.00</td> - <td class="tdc bb">29.50</td> - <td class="tdc bb">70.50</td> - </tr><tr> - <td class="tdc">e</td> - <td class="tdl_ws1 bb"> </td> - <td class="tdc bb">h</td> - <td class="tdc bb"> </td> - <td class="tdc bb"><b>Nitrogene</b></td> - <td class="tdc bb"><b>Hydrogene</b></td> - </tr><tr> - <td class="tdc">n</td> - <td class="tdc" rowspan="2">With<br /> hydrogene </td> - <td class="tdl_ws1" rowspan="2">Ammoniac</td> - <td class="tdc"> </td> - <td class="tdc">18.05</td> - <td class="tdc">80.00</td> - <td class="tdc">20.00</td> - </tr><tr> - <td class="tdc">e</td> - <td class="tdc"> </td> - <td class="tdc"> </td> - <td class="tdc"> </td> - <td class="tdc"> </td> - </tr><tr> - <td class="tdc bt" colspan="8"> </td> - </tr> - </tbody> -</table> - -<p><span class="pagenum" id="Page_566">[Pg 566]</span></p> - -<p id="APP_III" class="f120 space-above1">No. III.</p> - -<p class="center"><i>Additional Observations.</i></p> - -<p><i>a.</i> In <a href="#RI_DIV_03">Res. 1st. Div. IV. Sect. III</a>. -in the analysis of nitrous gas by pyrophorus, as no absorption took -place when the residual nitrogene was exposed to water, I inferred that -if any carbonic acid was formed it was in quantity so minute, as to be -unworthy of notice. A few days ago, I compleatly decomposed a quantity -of nitrous gas by pyrophorus, when the residual nitrogene was exposed -to solution of strontian, the fluid became slightly clouded; but no -perceptible absorption took place.</p> - -<p><i>b.</i> If there was the least probability in any of Dr. Girtanner’s -speculations on the composition of Azote,<a id="FNanchor_235" href="#Footnote_235" class="fnanchor">[235]</a> -the experiments on the exhausted capacity<a id="FNanchor_236" href="#Footnote_236" class="fnanchor">[236]</a> -of the lungs in Res. III. might be supposed inconclusive. But there -<span class="pagenum" id="Page_567">[Pg 567]</span> -appears to be no more reason for supposing that hydrogene is converted -into nitrogene by respiration, than for supposing that it is converted -into water, carbonic acid or oxygene; for all these products are -evolved when that gas is respired. From the comparison of Exp. 1 with -Exp. 3, <a href="#RIII_DII_04">Res. iii. Div. ii. Sec. 4</a>, it is -almost demonstrated that no ascertainable change is effected in -hydrogene by respiration. The experiment of the accurate Scheele in -which hydrogene after being respired thirty times in a bladder wholly -lost its inflammability, may be easily accounted for from its mixture -with the residual gases of the lungs.</p> - -<p>About a fortnight ago, I respired, after forced voluntary exhaustion of -my lungs, my nose being accurately closed, three quarts of hydrogene in -a silk bag, at four intervals, for near five minutes. After this it was -highly inflammable, and burnt with a greenish white flame in contact -with the atmosphere; but was not so explosive as before.<a id="FNanchor_237" href="#Footnote_237" class="fnanchor">[237]</a></p> - -<p><span class="pagenum" id="Page_568">[Pg 568]</span> -<i>c.</i> From what we have lately heard of the curious experiments of -Mr. Volta and Mr. Carlisle, it is very probable that the conversion of -nitrous gas into nitrous oxide when exposed to wetted zinc, copper and -tin, in contact with mercury, as described in <a href="#RI_DIV_V">Res. I. Div. V</a>. -may in some measure depend on the action of the galvanic fluid. Whilst I was -engaged in the experiments on this conversion, Dr. Beddoes<a id="FNanchor_238" href="#Footnote_238" class="fnanchor">[238]</a> -mentioned to me some curious facts noticed by Humboldt and Ritter, relating -to the oxydation of metals by the decomposition of water, which induced -me to examine the phænomena with more attention than I should have -otherwise done.—I recollect observing that some of the wetted zinc -<span class="pagenum" id="Page_569">[Pg 569]</span> -filings in nitrous gas on the side of the jar not in contact with the -surface of mercury, were very slowly oxydated. Whilst on the surface -<span class="pagenum" id="Page_570">[Pg 570]</span> -of the mercury where small globules of that substance were mingled with -the filings of zinc, the decomposition went on much more rapidly; -<span class="pagenum" id="Page_571">[Pg 571]</span> -possibly through the medium of the moisture, a series of galvanic -circles were formed.</p> - -<p><i>d.</i> In <a href="#RII_DIV_I">Res. II. Div</a>. I. it is stated, -that nitrous oxide during its solution by common water, expels about -¹/₁₆ of atmospheric air the volume of the water being unity. -<span class="pagenum" id="Page_572">[Pg 572]</span></p> - -<p>From the delicate experiments of Dr. Pearson, on the passage of the -electric spark through water, it appears however probable, that much -more than ¹/₁₆ of atmospheric air is sometimes held in solution by that -fluid,<a id="FNanchor_239" href="#Footnote_239" class="fnanchor">[239]</a> -possibly the whole of the air is not expelled by nitrous oxide, owing -to some unknown law of saturation by which an equilibrium of affinity -is produced, forming a triple compound. -<span class="pagenum" id="Page_573">[Pg 573]</span></p> - -<p id="APP_IV" class="f120 space-above1">No. IV.</p> - -<p class="f120">DESCRIPTION OF A MERCURIAL AIRHOLDER.</p> - -<p class="center">Suggested by an inspection of Mr. <span class="smcap">Watt’s</span> Machine for -containing Factitious Airs.</p> - -<p class="f120"><i>By WILLIAM CLAYFIELD</i>.</p> - -<p class="drop-cap"><span class="smcap">Several</span> modes of -counteracting the pressure of a decreasing column of mercury having -been thought of in conjunction with Mr. W. Cox, the following was at -last adopted as the most simple and effectual.</p> - -<p><a href="#PLATE_1">Plate 1 Fig. 1</a>, represents a section of the -machine, which consists of a strong glass cylinder A cemented to one of -the same kind B, fitted to the solid block C, into which the glass tube -D is cemented for conveying air into the moveable receiver E.</p> - -<p>The brass axis <a href="#PLATE_1">F, Fig. 2</a>, having a double bearing at <i>a</i>, -<i>a</i>, is terminated at one end by the wheel G, the circumference of -which is equal to the depth of the receiver, so that it may be drawn to -the surface of the mercury by the cord <i>b</i> in one revolution; to -<span class="pagenum" id="Page_574">[Pg 574]</span> -the other end is fitted the wheel H, over which the balance cord -<i>c</i> runs in an opposite direction in the spiral groove <i>e</i>, a -front view of the wheel H is shewn at <a href="#PLATE_1">Fig. 3</a>.</p> - -<p>Having loaded the receiver with the weight I, something heavier than -may be necessary to force it through the mercury, it is balanced by -the small weight K, which hangs from that part of the spiral where the -radius is equal to that of the wheel G, from this point the radius -of the spiral must be increased in such proportion, that in every -part of its circuit, the weight K may be an exact counterpoise to the -airholder. In this way, so little friction will be produced, that -merely plunging the lower orifice of the tube D under mercury contained -in the small vessel L, will be sufficient to overcome every resistance, -and to force the gas discharged from the beak of a retort into the -receiver, where whatever may be its quantity, it will be subjected to a -pressure exactly corresponding to that of the atmosphere. The edge of -the wheel H being graduated, the balance cord <i>c</i> may be made to -indicate its volume. -<span class="pagenum" id="Page_575">[Pg 575]</span></p> - -<p>Should it at any time be necessary to reduce the pressure to the medium -standard of the barometer, it may easily be done by graduating the -lower end of the tube D, and adding to the weights I or K, as may be -found necessary; the surface of the mercury in the tube pointing out -the increase or diminution.</p> - -<p>The concavity at the top of the internal cylinder is intended to -contain any liquid it may be thought proper to expose to the action of -the gas.</p> - -<p>The upper orifice <i>f</i>, with its ground stopper, is particularly -useful in conveying air from the retort <i>g</i>, with its curved neck, -into the receiver, without its passing through the tube D. In all cases -where a rapid extrication of gas is expected the retort <i>g</i>, -should be firmly luted to the orifice and the weight I, removed from -the top of the receiver, this by diminishing the pressure, will admit -the gas to expand freely in the airholder at the instant of its -formation, and prevent an explosion of the vessels. The same caution -must be observed whenever any inflammation of gas is produced by the -electric spark.</p> - -<p>The air may be readily transferred through water or even mercury by the -tube <i>h</i>, <a href="#PLATE_1">Fig. 1</a>. -<span class="pagenum" id="Page_576">[Pg 576]</span></p> - -<p>To prevent an absorption of mercury in case of a condensation taking -place in the retort made use of for generating air, Mr. Davy has -applied the stop-cock <i>i</i>, to which the neck is firmly luted. This -stop-cock is likewise of great service in saturating water with acid -or alkaline gases, which may be effected by luting one end of the tube -<i>k</i> to the stop-cock, and plunging the other into the fluid in the -small vessel <i>l</i>, cemented at top, and terminating in the bent -funnel <i>m</i>—the tube <i>h</i> having been previously removed, -and the lower orifice of the tube D either sunk to a considerable depth -in mercury, or closed with a ground stopper. The bend of the funnel -<i>m</i>, may be accurately closed by the introduction of a few lines -of mercury.</p> - -<p>The application of the stop-cock <i>n</i>, has enabled Mr. Davy to -perform some experiments on respiration with considerable accuracy.</p> - -<p class="blockquot"> <i>Note.</i> This apparatus was first described -in the third part of Dr. Beddoes’s Considerations; its relation to Mr. -Davy’s experiments with the improvements it has lately received, may -probably be deemed sufficient to excuse the re-printing it.—The -weight I. <a href="#PLATE_1">Fig. 2</a>, having been omitted in the -plate, the reader must supply the deficiency.</p> - -<p class="author">W. C.</p> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p id="APP_V"><span class="pagenum" id="Page_577">[Pg 577]</span></p> -<p class="f150"><b>PROPOSALS</b></p> -<p class="center">FOR THE PRESERVATION OF</p> -<p class="f120"><b>ACCIDENTAL OBSERVATIONS</b></p> -<p class="center">IN</p> -<p class="f120"><b>MEDICINE.</b></p> -</div> - -<p class="drop-cap"><span class="smcap">In</span> times beyond the -reach of history, the medicinal application of substances could have -arisen from no other source than accident. Among articles of the -materia medica of known origin, we are indebted to accident for some of -the most precious.</p> - -<p>Accident is every day presenting to different individuals the spectacle -of phænomena, arising from uncommon quantities of drugs on the one -hand, and on the other, from uncommon conditions of the system, where -ordinary powers only have been knowingly or recently applied. What is -said of drugs may be extended to natural agents and mental affections.</p> - -<p>From conversation with a variety both of medical practitioners and -unprofessional observers, the author of this proposal is persuaded -that such authentic occurrences only, as have presented themselves to -persons now living would, if they could be brought together, compose -a body of fact, so instructive to the philosopher, and useful to the -physician, that he despairs of finding a term worthy to characterize it. -<span class="pagenum" id="Page_578">[Pg 578]</span></p> - -<p>In some cases, the influence of unsuspected powers would be detected. -In others, resources available to the purpose of restoring health in -desperate situations would be directly presented, or could be detected -by a short and easy process of reasoning. Some anomalous observations, -by shewing the absence or agency of contested causes, would perform the -office of <i>experimenta crucis</i>—Unusual affections occur of which -an exact account would be among the means of removing from physic its -opprobrious uncertainty: for this uncertainty frequently depends upon -our inability to distinguish the subtler differences in cases which -resemble each other in their grosser features.</p> - -<p>No striking fact can be accurately stated, in conjunction with its -antecedent and concomitant circumstances, without improving our -acquaintance with human nature. Our acquisitions in this most important -branch of knowledge, may be compared to a number of broken series, of -which we have not always more than one or two members. But every new -accession bids fair to fill up some deficiency; and a large supply -would contribute towards connecting series apparently independent, and -working up the whole into one grand all-comprehending chain.</p> - -<p>There are complaints, and those by far too frequent, where no known -process has a claim to the title of <i>remedial</i>. Here the whole -chance of preservation depends on the physician’s capacity for bringing -together facts that have heretofore stood remote. But no power of -combination can avail where there are no ideas to combine.</p> - -<p>Every new observation therefore, may be considered as a standard trunk, -sending forth analogies as so many branches crowned with blossoms, some -of which cannot fail to be succeeded by salutary fruits. And were it -not absurd to extend the illustration of so plain a point, it might be -<span class="pagenum" id="Page_579">[Pg 579]</span> -added, that when by the continual interposition of new trunks, the -branches are brought near together, the produce of each will be -ennobled by the action of their respective principles of fecundation.</p> - -<p>Whenever the author has been able to obtain certain information -concerning any unusual appearance in animal nature, it has been his -custom to preserve it; and among his papers he has memorandums which -prove that to our present circumscribed ideas concerning the dose of -medicines may be sometimes imputed failures in practice; that certain -signs are not to be taken in the received signification; and that many -measures are adopted or omitted to the detriment of invalids, because -it is assumed that circumstances are necessarily connected which may -exist separately, or that one given natural operation is inconsistent -with another, to which it may really be synchronous or next in order.</p> - -<p>Assiduous observation of the daily states of the human microcosm will -be the unfailing consequence of attention to its striking phænomena. -Such is the progress of curiosity. Such the origin of all the sciences. -The more uniformly clear the sky under which they tended their flocks, -the less likely were the shepherds of Chaldæa, to found the science of -the stars. And however the disposition to study astronomy might have -been strengthened by the coincidence between the heliacal rising of -Sirius and the overflowing of the Nile, it must, I conceive, have been -awakened by the aspect of meteors and eclipses.</p> - -<p>Whatever minute and authentic information this imperfect statement -may produce, as soon as it shall amount to a certain mass, the author -will present it to the public arranged. He flatters himself that -no correspondent will eke out by supposition the defect of genuine -<span class="pagenum" id="Page_580">[Pg 580]</span> -observation, without clearly distinguishing the one from the other. -He still more confidently hopes that none will be instigated by this -advertisement to exercise his invention in the manner of Psalmanasar -and Chatterton. Whether any literary forgery can be innocent is -questioned—but a forged medical report is a drawn dagger which the -arm of a credulous physician may any day plunge into the heart of his -defenceless patient. The author has heard some inconsiderate wits avow, -that they have transmitted to the venders of quack medicines imaginary -cures, attested by fictitious signatures; and it is not without -apprehension from the propensity of men to display ingenuity and to -relate wonders that he announces the present design. But he shall be on -his guard, and hopes to baffle attempts at imposition.</p> - -<p class="author">THOMAS BEDDOES.</p> -<p><span class="smcap">Rodney-Place</span>, Clifton, June 1800.</p> - -<hr class="r5" /> - -<p class="f150"><b>END.</b></p> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<h2 class="nobreak">ERRATA.</h2> -</div> - -<table border="0" cellspacing="0" summary="ERRATA" cellpadding="0" > - <tbody><tr> - <td class="tdc">Page</td> - <td class="tdr"> 19</td> - <td class="tdl_ws1">line 15</td> - <td class="tdl_ws1">for <i>is</i> read <i>are</i></td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">35</td> - <td class="tdl_ws1">—   7 —</td> - <td class="tdl_ws1">for <i>principle</i> read <i>principles</i></td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">42</td> - <td class="tdl_ws1">—  11 —</td> - <td class="tdl_ws1">for <i>take</i> read <i>takes</i></td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">68</td> - <td class="tdl"> Table 5 —</td> - <td class="tdl_ws1">for 5,88 read 15,88</td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">94</td> - <td class="tdl_ws1">—   4 —</td> - <td class="tdl_ws1">for 1¹/₁₂ read ¹/₁₂.</td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">95</td> - <td class="tdl_ws1">—   4 —</td> - <td class="tdl_ws1">for 37 read 30,7</td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">96</td> - <td class="tdl_ws1">—   3 —</td> - <td class="tdl_ws1">for 38 read ¹/₃₈</td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">105</td> - <td class="tdl_ws1">—   9 —</td> - <td class="tdl_ws1">for <i>exactitude</i> read <i>exactness</i></td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">129</td> - <td class="tdl_ws1">—  21 —</td> - <td class="tdl_ws1">for 41 read 4,1</td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">132</td> - <td class="tdl_ws1">—   4 —</td> - <td class="tdl_ws1">for <i>into</i> read <i>in</i></td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">143</td> - <td class="tdl_ws1">—  13 —</td> - <td class="tdl_ws1">for 25 read ,25</td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">186</td> - <td class="tdl_ws1">—  15 —</td> - <td class="tdl_ws1">for <i>by</i> read <i>from</i></td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">208</td> - <td class="tdl"> last line —</td> - <td class="tdl_ws1">for <i>abstracted</i> read <i>attracted</i></td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">238</td> - <td class="tdl_ws1">—   5 —</td> - <td class="tdl_ws1">for <i>gas</i> read <i>oxide</i></td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">259</td> - <td class="tdl_ws1">—   4 —</td> - <td class="tdl_ws1">for 12 read 2</td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">283</td> - <td class="tdl_ws1">—   4 —</td> - <td class="tdl_ws1">for <i>potash</i> read <i>iron</i></td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">315</td> - <td class="tdl_ws1">—  14 —</td> - <td class="tdl_ws1">dele <i>in</i></td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">409</td> - <td class="tdl_ws1">—  15 —</td> - <td class="tdl_ws1">for <i>respiration</i> read <i>expiration</i></td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">464</td> - <td class="tdl_ws1">—  10 —</td> - <td class="tdl_ws1">for <i>latter end</i> read <i>end</i></td> - </tr><tr> - <td class="tdc">—</td> - <td class="tdr">543</td> - <td class="tdl_ws1">—   3 —</td> - <td class="tdl_ws1">for <i>exhalation</i> read <i>inhalation</i>.</td> - </tr><tr> - <td class="tdc bt" colspan="4">A few literal errors are left to the reader’s correction.</td> - </tr> - </tbody> -</table> - -<div class="blockquot2"> -<p class="space-above1">N. B. The term ignited is sometimes used to -signify any temperature equal to or above a red heat, whether applied -to solids, fluids, or aëriform substances.</p> - -<p>The reasons for the use of the terms nitrogene and nitrous oxide, are -given in Mr. Nicholson’s Journal for January.</p> -</div> - -<hr class="chap x-ebookmaker-drop" /> - -<p class="center space-below2"><i>Speedily will be Published</i></p> - -<p class="center">OBSERVATIONS on the External and Internal Use of</p> -<p class="f120">NITROUS ACID.</p> - -<p class="center">Demonstrating its PERMANENT EFFICACY in</p> -<p class="f120 space-above2">VENEREAL COMPLAINTS;</p> - -<p class="center">And extending its use to other dangerous<br /> -and painful Diseases.</p> - -<p class="center space-above2">COMMUNICATED<br /> -By various Practitioners in <span class="smcap">Europe</span> and <span class="smcap">Asia</span>.</p> - -<p class="f120"><small>TO</small><br />THOMAS BEDDOES, M. D.</p> -<hr class="r5" /> - -<p class="center space-above2"><i>Of the Publisher may be had, price 1s. 6d.</i></p> - -<p class="f150">NOTICE of OBSERVATIONS</p> -<p class="center">AT THE PNEUMATIC INSTITUTION,</p> -<p class="center space-below2"><i>By THOMAS BEDDOES, M. D.</i></p> - -<div class="blockquot2"> -<p class="neg-indent">This Notice contains some trials of nitrous oxide -by healthy persons, not in the present work, and some cases of palsy -successfully treated by that gas.</p> -</div> - -<hr class="chap x-ebookmaker-drop" /> - -<p class="center space-below2"><i>Printed by Biggs and Cottle, St. Augustine’s Back.</i></p> - -<hr class="full" /> - -<div class="footnotes space-above2"> -<p class="f150"><b>Footnotes:</b></p> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_1" href="#FNanchor_1" class="label">[1]</a> -A short account of this discovery has been given in Dr. Beddoes’s -Notice of some Observations made at the Pneumatic Institution, and in -Mr. Nicholson’s Phil. Journal for May and December 1799.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_2" href="#FNanchor_2" class="label">[2]</a> -Cavendish, Priestley, Black, Lavoisier, Scheele, Kirwan, -Guyton, Berthollet, &c.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_3" href="#FNanchor_3" class="label">[3]</a> -Phil. Trans. v. 78, p. 270.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_4" href="#FNanchor_4" class="label">[4]</a> -Phil. Trans. v. 75 p. 381.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_5" href="#FNanchor_5" class="label">[5]</a> -Elem. Kerr’s Trans. page 76, and 216, and Mem. des Sav. -Etrang. tom. 7, page 629.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_6" href="#FNanchor_6" class="label">[6]</a> -Ingenhouz sur les Vegetaux, pag. 205. De la Metherie. -Essai sur differens Airs, pag. 252.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_7" href="#FNanchor_7" class="label">[7]</a> -Annales de Chimie, tome 28, p. 168.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_8" href="#FNanchor_8" class="label">[8]</a> -Experiments and Observations, Vol. iii. last edition, page 105, &c.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_9" href="#FNanchor_9" class="label">[9]</a> -When copper is dissolved in dilute nitrous acid, certain -quantities of nitrogene are generally produced, likewise the -nitrous gas carries off in solution some nitrous acid.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_10" href="#FNanchor_10" class="label">[10]</a> -This airholder, considered as a pneumatic instrument, is -of greater importance, and capable of a more extensive application than -any other. It was invented by Mr. <span class="smcap">W. Clayfield</span>, and in its -form is analogous to Mr. <span class="smcap">Watt’s</span> hydraulic bellows, consisting -of a glass bell playing under the pressure of the atmosphere, in a -space between two cylinders filled with mercury. A particular account -of it will be given in the <a href="#APP_IV">appendix</a>.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_11" href="#FNanchor_11" class="label">[11]</a> -This absorption will be hereafter particularly treated of.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_12" href="#FNanchor_12" class="label">[12]</a> -Annales de Chimie. Tome xviii. page 139.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_13" href="#FNanchor_13" class="label">[13]</a> -A table of the specific gravities of these gases, and -other gases, hereafter to be mentioned, reduced to a barometrical -and thermometrical standard, will be given in the <a href="#APP_II">appendix</a>.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_14" href="#FNanchor_14" class="label">[14]</a> -40 measures, exposed to solution of potash, gave an absorption of not -quite a quarter of a measure: hence it contained an inconsiderable -quantity of carbonic acid.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_15" href="#FNanchor_15" class="label">[15]</a> -Traité Elementaire.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_16" href="#FNanchor_16" class="label">[16]</a> -Essai sur le phlogistique, page 30.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_17" href="#FNanchor_17" class="label">[17]</a> -The diminution of the specific gravity of the gas from the -quantity of nitrogene evolved in his experiment, probably destroyed, in -some measure, the source of error from the nitrous acid carried over.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_18" href="#FNanchor_18" class="label">[18]</a> -Experiment I.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_19" href="#FNanchor_19" class="label">[19]</a> -That no greater contraction took place depended on the solution of the -nitrous acid formed in the nitrous gas; a phænomenon to be explained -hereafter.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_20" href="#FNanchor_20" class="label">[20]</a> -I judged it expedient always to ascertain the quantity -of air in the stop-cocks by weight, as it was impossible to join them -so as to have always an equal capacity. The upper tubes of the two -stop-cocks not joined, contained nearly an inch and half.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_21" href="#FNanchor_21" class="label">[21]</a> -That is, by the solution of ammonia, and air.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_22" href="#FNanchor_22" class="label">[22]</a> -The following is an account of the increase and diminution -of weight of the globe, as it was noted in the journal.</p> - -<table border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdl">Globe filled with common air</td> - <td class="tdr">gr. 2066,5 </td> - </tr><tr> - <td class="tdl">After exhaustion</td> - <td class="tdr">2034,5 </td> - </tr><tr> - <td class="tdl">After introduction of nitrous gas, 82 cubic inches</td> - <td class="tdr">2064,25</td> - </tr><tr> - <td class="tdl">After the accidental admission of common air</td> - <td class="tdr">2067,25</td> - </tr><tr> - <td class="tdl">After the admission of oxygene</td> - <td class="tdr">2091,75</td> - </tr><tr> - <td class="tdl">—— —— 41 grains of water</td> - <td class="tdr">2133,25</td> - </tr><tr> - <td class="tdl">—— —— 51 cubic inches of air</td> - <td class="tdr">2149,75</td> - </tr><tr> - <td class="tdl">Taken out 54 grains of solution</td> - <td class="tdr">2095,75</td> - </tr><tr> - <td class="tdl">Introduced 13 grains of ammoniacal solution</td> - <td class="tdr">2109,25</td> - </tr><tr> - <td class="tdl">After introduction of common air</td> - <td class="tdr">2106,5 </td> - </tr> - </tbody> -</table> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_23" href="#FNanchor_23" class="label">[23]</a> -Decimals are omitted, because the excess of the two first -numbers is exactly corrected by the deficiency of the last.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_24" href="#FNanchor_24" class="label">[24]</a> -As is evident from the superabundant quantity of oxygene -thrown into the globe.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_25" href="#FNanchor_25" class="label">[25]</a> -The weight of the acid poured into the cylinder being known, its -specific gravity was known from the space it occupied in the phial. -The weight of water being likewise known, the specific gravity of the -solution, when the common temperature was produced, was given by the -condensation.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_26" href="#FNanchor_26" class="label">[26]</a> -That is, such as it exists in the aëriform state at 55°. -From the strong affinity of nitrous acid for water, we may suppose that -this acid gas contains a larger proportion of it than the other gases.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_27" href="#FNanchor_27" class="label">[27]</a> -This appearance will be explained hereafter.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_28" href="#FNanchor_28" class="label">[28]</a> -This phænomenon will be particularly explained hereafter.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_29" href="#FNanchor_29" class="label">[29]</a> -The outline only of this apparatus is given here, as far as was -necessary to make the experiment intelligible; a detailed account of -it, and of its general application, will be given in the <a href="#APP_IV">appendix</a>.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_30" href="#FNanchor_30" class="label">[30]</a> -That is, from nitrous acid and mercury.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_31" href="#FNanchor_31" class="label">[31]</a> -A pale acid of 1.52, by being converted into yellow acid, -became nearly of specific gravity 15,1.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_32" href="#FNanchor_32" class="label">[32]</a> -It is impossible to ascertain the quantity of gas absorbed -to more than a quarter of a cubic inch, as the first portions of -nitrous gas thrown into the graduated cylinder are combined with the -oxygene of the common air in it, to form nitrous acid, and hence the -slight excess of weight.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_33" href="#FNanchor_33" class="label">[33]</a> -In a letter to me, dated Oct. 28, 1799, after giving an -account of some experiments on the phlogistication of nitric acid -by heat and light, he says, “It was from an attentive examination -of the manner in which the nitric acid was phlogisticated in these -experiments, that I was confirmed in the suspicion I had long before -entertained, of the real difference between the <i>nitrous</i> -and <i>nitric</i> acids. It is not enough to shew that in the -<i>nitrous</i> acid, (that is, the nitric holding nitrous gas in -solution), the proportion of oxygene in the whole compound is less than -that entering into the composition of the nitric acid, and that it is -therefore less oxygenated. By the same mode of reasoning we might prove -that water, by absorbing carbonic acid gas, became less oxygenated, -which is absurd. Should any one attempt to prove (which will be -necessary to substantiate the generally received doctrine) that the -oxygene of the nitrous gas combines with the oxygene of the acid, and -the nitrogene, in like manner, so that the resulting acid, when nitrous -gas is absorbed by nitric acid, is a binary combination of oxygene -and nitrogene, he would find it somewhat more difficult than he at -first imagined; it appears to me impossible. It is much more consonant -with experiment to suppose that nitrous acid is nothing more than -nitric acid holding nitrous gas in solution, which might in conformity -to the principles of the French nomenclature, be called nitrate of -nitrogene. The difficulty, and in some cases the impossibility, of -forming nitrites, arises from the weak affinity which nitrous gas -has for nitric acid, compared with that of other substances; and -the decomposition of nitrous acid (that is, nitrate of nitrogene) -by an alkaline or metallic substance, is perfectly analogous to the -decomposition of any other nitrate, the nitrous gas being displaced by -the superior affinity of the alkali for the acid.</p> - -<p>“Agreeable to this theory, the salts denominated <i>nitrites</i> are in -fact triple salts, or ternary combinations of nitric acid, nitrous gas, -and salifiable bases.”</p> - -<p>This theory is perfectly new to me. Other Chemists to whom I have -mentioned it, have likewise considered it as new. Yet in a subsequent -letter Mr. Thomson mentions that he had been told of the belief of a -similar opinion among the French Chemists.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_34" href="#FNanchor_34" class="label">[34]</a> -In some experiments made on the nitrites of potash, and of ammoniac, -before I was well acquainted with the composition of nitric acid, I -found that a light olive-colored acid of 1,28, was capable of being -saturated by weak solutions of potash and ammoniac, without losing any -nitrous gas; but after the evaporation of the neutralised solution, -at very low temperatures, the salts in all their properties resembled <i>nitrates</i>.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_35" href="#FNanchor_35" class="label">[35]</a> -As is evident from the curious appearance of the dark -green spherules, repulsive both to water, and light green acid.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_36" href="#FNanchor_36" class="label">[36]</a> -That is, undecompounded.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_37" href="#FNanchor_37" class="label">[37]</a> -The existence of these bodies will be hereafter proved.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_38" href="#FNanchor_38" class="label">[38]</a> -The blue green acid is not homogeneal in its composition, -it is composed of the blue green spherules and the bright green acid. -The blue green spherules are of greater specific gravity than the dark -green acid, probably because they contain little or no water.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_39" href="#FNanchor_39" class="label">[39]</a> -The composition of the acids thus marked, is given from calculations.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_40" href="#FNanchor_40" class="label">[40]</a> - Nitrous gas contains 44,05 Nitrogene, and 55,95 Oxygene, -as has been said before.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_41" href="#FNanchor_41" class="label">[41]</a> -A great portion of it, of course, dissolved in the water -with the nitrous acid carried over.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_42" href="#FNanchor_42" class="label">[42]</a> -Their changes of volume, corresponding to changes of -temperature, most probably, are likewise different.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_43" href="#FNanchor_43" class="label">[43]</a> -Probably in the ratio of the square of the quantity of water united to it.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_44" href="#FNanchor_44" class="label">[44]</a> -The quantities of Oxygene and Nitrogene in any solution, may be thus -found—— Let A = the true acid, X the oxygene, and Y the -nitrogene.</p> - -<p>Then</p> - -<table border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdc"> </td> - <td class="tdc">238 A</td> - <td class="tdc"> </td> - <td class="tdc">A</td> - </tr><tr> - <td class="tdc">X =</td> - <td class="tdc_ws1">———</td> - <td class="tdc">and Y =</td> - <td class="tdc_ws1">———</td> - </tr><tr> - <td class="tdc"> </td> - <td class="tdc">239</td> - <td class="tdc"> </td> - <td class="tdc">239</td> - </tr> - </tbody> -</table> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_45" href="#FNanchor_45" class="label">[45]</a> -Experiments and Observations; last edition, vol. 1, page 384.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_46" href="#FNanchor_46" class="label">[46]</a> -Nitrous gas, holding in solution nitrous acid, is more readily absorbed -by water than when in its pure form, from being presented to it in a -more condensed state in the green acid, formed by the contact of water -and nitrous vapor.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_47" href="#FNanchor_47" class="label">[47]</a> -Mem. des Savans Etrangers, v. xi. 226. Vide Kirwan sur le -phlogistique pag. 110.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_48" href="#FNanchor_48" class="label">[48]</a> - In this experiment, as well as in the last, some of the -mixture was thrown into the jar undecompounded.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_49" href="#FNanchor_49" class="label">[49]</a> -To detach the potash from the carbonic acid.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_50" href="#FNanchor_50" class="label">[50]</a> -This nitrogene contained a little nitrous gas, as it gave red fumes -when exposed to the air. The free nitrous acid was decomposed by the -mercury, as it was not covered with water.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_51" href="#FNanchor_51" class="label">[51]</a> -Essay on phlogiston.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_52" href="#FNanchor_52" class="label">[52]</a> -Dr. Priestley says, “Having filled a phial containing exactly the -quantity of four pennyweights of water, with strong, pale, yellow -spirit of nitre, with its mouth quite close to the top of a large -receiver standing in water, I carefully drew out almost all the common -air, and then filled it with nitrous air; and as this was absorbed, -I kept putting in more and more, till in less than two days it had -completely absorbed 130 ounce measures. Presently after this process -began, the surface of the acid assumed a deep orange color, and when 20 -or 30 ounce measures of air were absorbed, it became green at the top: -this green descended lower and lower, till it reached the bottom of the -phial. Towards the end of the process, the evaporation was perceived to -be very great, and when I took it out, the quantity was found to have -diminished to one half. Also it had become, by means of this process, and -the evaporation together, exceeding weak, and was rather blue than green.”</p> - -<p><i>Experiments and Observations</i>, vol. 1, p. 384. Last edition.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_53" href="#FNanchor_53" class="label">[53]</a> -See Mr. Keir’s excellent observations on this subject. Chem. Dict. Art. Acid.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_54" href="#FNanchor_54" class="label">[54]</a> -Irish Transactions, vol. 4, p. 34.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_55" href="#FNanchor_55" class="label">[55]</a> -Addit. Obs. pag. 74.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_56" href="#FNanchor_56" class="label">[56]</a> -Additional Observations, page 70.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_57" href="#FNanchor_57" class="label">[57]</a> -Elements, pag. 103, Kerr’s Translation.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_58" href="#FNanchor_58" class="label">[58]</a> -Mem. Acad. 1787.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_59" href="#FNanchor_59" class="label">[59]</a> -As well as oxygene and nitrogene, Mr. Watt’s experiments -prove that much phlogisticated nitrous acid is produced.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_60" href="#FNanchor_60" class="label">[60]</a> -Journal de Physique, 1786. Tom. 2, pag. 176.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_61" href="#FNanchor_61" class="label">[61]</a> -Though the tube had never been used, and was apparently clean and dry -on the inside, it must have contained something in the form of dust, -capable of furnishing either hydrocarbonate, or charcoal.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_62" href="#FNanchor_62" class="label">[62]</a> -Journal de Physique, 1786, t. 2, 177.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_63" href="#FNanchor_63" class="label">[63]</a> -Phil. Trans. vol. 79, page 294.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_64" href="#FNanchor_64" class="label">[64]</a> -Vol. 2, page 398.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_65" href="#FNanchor_65" class="label">[65]</a> -Ammoniac generated at a temperature above that of the atmosphere, -always deposits ammoniacal solution during its reduction to the common -temperature.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_66" href="#FNanchor_66" class="label">[66]</a> -By the introduction of aëriform ammoniac into the exhausted globe.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_67" href="#FNanchor_67" class="label">[67]</a> -Additional Observations, page 107.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_68" href="#FNanchor_68" class="label">[68]</a> -It is necessary in these experiments, that the greatest care be -observed in the introduction and extraction of the capillary tube. If -it is introduced dry, there will be a source of error from the moisture -adhering to it when taken out. I therefore always wetted it before its -introduction, and took care that no more fluid adhered to it after the -experiment, than before.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_69" href="#FNanchor_69" class="label">[69]</a> -Previous to those experiments, I had made a number of others on the -combination of ammoniac with water.—My design was, to ascertain -the diminution of specific gravity for every three grains of ammoniac -absorbed; but this I found impossible. The capillary tube, when -taken out of the phial, always carried with it a minute portion of -the solution, which partially evaporated before it could be again -introduced; and thus the sources of error increased in proportion to -the number of examinations.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_70" href="#FNanchor_70" class="label">[70]</a> -The expansion from increase of temperature is probably -great in proportion to the quantity of ammoniac in the solution.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_71" href="#FNanchor_71" class="label">[71]</a> -From the combination.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_72" href="#FNanchor_72" class="label">[72]</a> -I had before proved that at this temperature the salt -neither decomposed nor sublimed.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_73" href="#FNanchor_73" class="label">[73]</a> -A particular account of the experiments from which these -facts were deduced, was printed in September, and will appear -in the first volume of the <i>Researches</i>.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_74" href="#FNanchor_74" class="label">[74]</a> -And which will be published, with an account of its perfect -decomposition at a high temperature, in the <i>Researches</i>.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_75" href="#FNanchor_75" class="label">[75]</a> -When nitrous gas exists in neutro-saline solutions, they -are always colored more or less intensely, from yellow to -olive, in proportion to the quantity combined with them.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_76" href="#FNanchor_76" class="label">[76]</a> -Hence a nitrate of ammoniac with excess of acid, when -exposed to heat, first becomes yellow, and then white.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_77" href="#FNanchor_77" class="label">[77]</a> -The accounts given by different chemists of the composition of nitrate -of ammoniac, are extremely discordant; they have been chiefly deduced -from decompositions of carbonate of ammoniac (the varieties of which -have been heretofore unknown) by nitrous acids of unknown degrees of -nitration. Hence they are particularly erroneous with regard to the -alkaline part. Wenzel supposes it to be 32 per cent, and Kirwan 24. -<i>Addit. Observ.</i> pag. 120.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_78" href="#FNanchor_78" class="label">[78]</a> -Mem. Par. 1783. See Irish Trans. vol. 4.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_79" href="#FNanchor_79" class="label">[79]</a> -Addit. Obs. pag. 120.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_80" href="#FNanchor_80" class="label">[80]</a> -Two measures of air dispelled from this water by boiling, -mingled with 2 of nitrous gas, diminished to 2,4 nearly.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_81" href="#FNanchor_81" class="label">[81]</a> -Experiments and Observations, vol. 2, pag. 89. Last Edition.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_82" href="#FNanchor_82" class="label">[82]</a> -A minute quantity, however, must have been absorbed, and -given out again when the charcoal was heated.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_83" href="#FNanchor_83" class="label">[83]</a> -Strong solution of ammoniac has no attraction for nitrous oxide.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_84" href="#FNanchor_84" class="label">[84]</a> -The gas was examined by those tests in order to prove that -no water had been decomposed.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_85" href="#FNanchor_85" class="label">[85]</a> -See the curious paper of this excellent philosopher, on -the combustion of the diamond, in which he proves that charcoal -is, in fact, oxide of diamond. Annales de Chimie, xxxi.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_86" href="#FNanchor_86" class="label">[86]</a> -This was actually the case; for on examining the conducting tube the -day after the experiment, some minute crystals of prismatic nitrate of -ammoniac were perceived in it.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_87" href="#FNanchor_87" class="label">[87]</a> -Owing part of their weight to an unknown quantity of water.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_88" href="#FNanchor_88" class="label">[88]</a> -Mem. de Paris. 1785, and Journal de Physique, 1786, page 175.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_89" href="#FNanchor_89" class="label">[89]</a> -The absorption of nitrous gas by sulphate of iron, &c. -will be treated of in the next division.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_90" href="#FNanchor_90" class="label">[90]</a> -As is evident from the decomposition of ammoniac by heat.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_91" href="#FNanchor_91" class="label">[91]</a> -Nitric acid is phlogisticated by heat, as appears from Dr. -Priestley’s experiments. Vol. 3, p. 26.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_92" href="#FNanchor_92" class="label">[92]</a> -As is evident from the increase of temperature required -for the formation of water.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_93" href="#FNanchor_93" class="label">[93]</a> -For ammoniac and nitrous oxide are both decomposed at the -red heat, and oxygene given out from nitric acid when it is passed -through a heated tube.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_94" href="#FNanchor_94" class="label">[94]</a> -Whenever nitrous acid is produced at high temperatures, it is always -highly phlogisticated, provided it has not been long in contact with -oxygene. When Dr. Priestley passed nitric acid through a tube heated -red, he procured much oxygene, and phlogisticated acid; and the water -in the apparatus employed was fully impregnated with nitrous air. Hence -it would appear, that heat diminishes the attraction between oxygene -and nitrous gas, and increases the affinity of nitrous gas for nitrous -acid. Mr. <span class="smcap">James Thomson</span>, whose theory of the -Nitrous Acid I have already mentioned, from some experiments on the -phlogistication of Nitric Acid by heat, which he has communicated to -me, concludes with great justness, that a portion of the acid is always -completely decomposed in this process: the oxygene liberated, and the -nitrous gas combined with the remaining acid.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_95" href="#FNanchor_95" class="label">[95]</a> -Except it be gold or platina.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_96" href="#FNanchor_96" class="label">[96]</a> -A pound of nitrate of ammoniac costs about 5s. 10d. This -pound, properly decomposed, produces rather more than 34 moderate doses -of air; so that the expence of a dose is about 2d. What fluid stimulus -can be procured at so cheap a rate?</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_97" href="#FNanchor_97" class="label">[97]</a> -Experiments and Observations, vol. II. pag. 50. Last Edition.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_98" href="#FNanchor_98" class="label">[98]</a> -That is, charcoal produced by the decomposition of -spirits of wine. Vol. II. pag. 39.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_99" href="#FNanchor_99" class="label">[99]</a> -Dr. Priestley says, “having heated iron in nitrous air, I proceeded -to heat in the same air, a piece of charcoal not long after it had -been subjected to a strong heat covered with sand. The sun not -shining immediately, after the charcoal was introduced into the -vessel of air, through the mercury by which it was confined, part -of the air was absorbed; but on heating the charcoal, the quantity -was increased. Having continued the progress as long as I thought -necessary, I examined the air and found it to be about as much as -the original quantity of nitrous air; but it was all phlogisticated -air extinguishing a candle and having no mixture of fixed air in -it.”—Experiments and Observations, Vol. II, page 39.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_100" href="#FNanchor_100" class="label">[100]</a> -That is, sulphate of iron containing oxide of iron, in the -first degree of oxygenation.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_101" href="#FNanchor_101" class="label">[101]</a> -That is, carbon, or oxide of diamond.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_102" href="#FNanchor_102" class="label">[102]</a> -That is, blue prussiate of iron.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_103" href="#FNanchor_103" class="label">[103]</a> -No luminous appearance is produced when phosphorus is introduced into -<i>pure</i> nitrous gas. It has been often observed, that phosphorus is -luminous in nitrous gas, that has not been long in contact with water -after its production. This phænomenon, I suspect, depends either on the -decomposition of the nitric acid held in solution by the nitrous gas; -or on the combination of the phosphorus with oxygene loosely adhering -to the binary aëriform compound of nitric acid and nitrous gas. I -have not yet examined if nitrous gas can be converted into nitrous -oxide by long exposure to heated phosphorus: it appears, however, very -probable.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_104" href="#FNanchor_104" class="label">[104]</a> -Perhaps this fact has been noticed before; I have not, -however, met with it in any chemical work.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_105" href="#FNanchor_105" class="label">[105]</a> -This mode of inflaming bodies in gases, not capable -of supporting combustion at low temperatures, will be -particularly described hereafter.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_106" href="#FNanchor_106" class="label">[106]</a> -Elements English Trans. edit. i. pag. 216.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_107" href="#FNanchor_107" class="label">[107]</a> -Experiments and Observations, Vol. II. pag. 40, 2d. Ed.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_108" href="#FNanchor_108" class="label">[108]</a> -He says, “On a observé, (depuis qu’on travaille sur -le pureté de l’air) que le gaz nitreux, secoué avec l’eau, en -souffre une diminution de volume. Quelques physiciens attribuent -ce changement à une vraie absorption, à une dissolution du gaz -nitreux dans l’eau; d’autres à l’air contenu dans les interstices de -tous les fluides. Le cit. Vanbreda, à Delft, a fait des recherches -très-exactes sur l’influence des eaux de pluie et de puit, sur les -nombres eudiométriques; et les belles expériences du cit. Hassenfratz, -sur l’abondance d’oxygène, contenue dans les eaux de neige et de -pluie, sont supposer que l’air des interstices de l’eau joue un rôle -important dans l’absorption du gaz nitreux. En comparant ces effets -avec les phénomènes observé dans la decomposition du sulfate de fer, -nous supposâmes, le cit. Tassaert et moi, que le simple contact du gaz -nitreux avec l’eau distillée pourroit bien causer une décomposition de -ce dernier. Nous examinâmes soigneusement une petite quantité d’eau -distillée, secouée avec beaucoup de gas nitreux trés-pur, et nous -trouvâmes, au moyen de la terre calcaire, et l’acide muriatique, qu’il -s’y forme du <i>nitrate d’ammoniaque</i>. L’eau se décompose en cette -opération, par un double affinité de l’oxygene pour le gaz nitreux, -et de l’hydrogène pour l’azote; il se forme de l’acide nitrique et de -l’<i>ammoniaque</i>; et, quoique la quantité du dernier paroisse trop -petite pour en évaluer exactment la quantité, son existence cependant -se manifeste, (à ne pas sans douter) par le dégagement des vapeurs, -qui blanchissent dans la proximité de l’acide muriatique. Voilá un -fait bien frappant que la composition d’une substance alcaline par le -contact d’une acide, et de l’eau.”</p> -<p class="author">Annales de Chimie, t. xxviii. pag. 153.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_109" href="#FNanchor_109" class="label">[109]</a> -Which was certainly as free from air as it ever can be obtained.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_110" href="#FNanchor_110" class="label">[110]</a> -Dr. Priestley found distilled water, saturated with nitrous air, -to acquire an astringent taste and pungent smell. In some unboiled -impregnated pump water, I once thought that I perceived a subacid -taste; but it was extremely slight, and probably owing to nitrous acid -formed by the union of the oxygene of the common air in the water, with -some of the nitrous gas.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_111" href="#FNanchor_111" class="label">[111]</a> -As carbonic acid and ammoniac are both products of animalisation, is -it not probable that our common waters particularly those in, and -near towns and cities, contain carbonate of ammoniac? If so, this -salt will always exist in them after distillation. In the experiments -on carbonate of ammoniac, to which I have often alluded, I found, in -distilling a solution of this salt in water, that before half of the -water had passed into the recipient, the carbonate of ammoniac had -sublimed; so that the distilled solution was much stronger than before, -whilst the water remaining in the retort was tasteless. Will this -supposition at all explain Humbolt’s mistake?</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_112" href="#FNanchor_112" class="label">[112]</a> -The water still being unity.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_113" href="#FNanchor_113" class="label">[113]</a> -He says “100 parties de gaz nitreux, (à 0.14 d’azote) secouées avec -l’eau distillée, récemment cuite, diminuent en volume de 0.11, ou 0.12. -Ce même gaz, en contact avec l’eau de puits, ne perd que 0.02. La -cause de cette différence de 0.9, ou 0.10, ne doit pas être attribuée -ni à l’impurité de l’air atmosphérique, contenu dans les interstices -de l’eau, ni à la décomposition de cette eau même. Elle n’est -qu’apparente; car l’acide nitrique, qui se forme par le contact du gaz -nitreux avec l’eau de puits, en décompose le carbonate de chaux. Il se -dégage de l’acide carbonique, qui, en augmentant le volume du residu, -rend l’absorption du gaz nitreux moins sensible. Pour déterminer la -quantité de cet acide carbonique, je lavai le résidu avec de l’eau de -chaux. Dans un grand nombre d’expériences, le volume diminua de 0.09, -ou 0.07. Il faut en conduire que l’eau de puits absorbe réellement 9 + -2, ou 7 + 2 parties de gas nitreux, c’est-à-dire, à peu-près la même -quantité que l’eau distillée.”</p> -<p class="author">Annales De Chimie, xxviii. pag. 154.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_114" href="#FNanchor_114" class="label">[114]</a> -Nicholson’s Phil. Jour. No. 1, p. 453.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_115" href="#FNanchor_115" class="label">[115]</a> -I have been able to make these observations on the -sulphates of iron, most of them after Proust.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_116" href="#FNanchor_116" class="label">[116]</a> -Annales de Chimie, vol. xxviii. pag. 182.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_117" href="#FNanchor_117" class="label">[117]</a> -<a href="#RI_DV_05">Division IV. Section 5.</a></p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_118" href="#FNanchor_118" class="label">[118]</a> -<a href="#RI_DII_01">Division II. Section 1</a>.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_119" href="#FNanchor_119" class="label">[119]</a> -No precipitation takes place during the conversion of -solution of green sulphate into red; and the acid appears saturated.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_120" href="#FNanchor_120" class="label">[120]</a> -Division II, Section 6.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_121" href="#FNanchor_121" class="label">[121]</a> -According to the estimation in the equation, 6.5 of dry green sulphate -of iron contain 4.1 green oxide of iron, and 2.4 of Kirwan’s real -sulphuric acid; and 8.1 red sulphate of iron, contain 2.4 acid, and 5.7 -red oxide of iron.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_122" href="#FNanchor_122" class="label">[122]</a> -The muddy green color produced in a solution of red sulphate of iron -agitated in nitrous gas, depended upon impurities in the mercury. I -have since found, that when the solution is completely oxygenated, the -diminution is barely perceptible.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_123" href="#FNanchor_123" class="label">[123]</a> -Perhaps the liberation of nitrous gas from the solution takes place -at a lower temperature than its decomposition. I have always observed -that the quantity of yellow precipitate is greater when the solution -is rapidly made to boil. Were it possible to heat it to a certain -temperature at once, probably a compleat decomposition would take place.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_124" href="#FNanchor_124" class="label">[124]</a> -Annales de Chimie. T. 38, pag. 187.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_125" href="#FNanchor_125" class="label">[125]</a> -Annales de Chimie, xxiii. pag. 85; or Nicholson’s Phil. Journal vol. i. pag. 45.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_126" href="#FNanchor_126" class="label">[126]</a> -Probably by giving them oxygene; whereas the green muriate and sulphate -blacken animal substances; most likely by abstracting from them oxygene.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_127" href="#FNanchor_127" class="label">[127]</a> -The existence of green nitrate was not suspected by Proust.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_128" href="#FNanchor_128" class="label">[128]</a> -In this process nitrous oxide is sometimes given out, as -will be seen hereafter.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_129" href="#FNanchor_129" class="label">[129]</a> -Hence we learn why no nitrous gas is disengaged when impregnated -solution of sulphate of iron is decomposed by prussiate of potash, as -in Div. IV. Sec. vii.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_130" href="#FNanchor_130" class="label">[130]</a> -In both of these solutions the metal is at its minimum of oxydation. -The absorption of a small quantity of nitrous gas by white vitriol was -observed by Priestley.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_131" href="#FNanchor_131" class="label">[131]</a> -Humbolt, who is the first philosopher that has applied the solution of -sulphate of iron to ascertain the purity of nitrous gas, asserts that -he uniformly found nitrous gas obtained from solution of copper in -nitrous acid, to contain from six tenths to one tenth nitrogene.</p> -<p class="author">Annales de Chimie, vol. xxviii. pag. 147.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_132" href="#FNanchor_132" class="label">[132]</a> -Vol. ii. pag. 55.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_133" href="#FNanchor_133" class="label">[133]</a> -Phil. Trans. vol. lxxvi. pag. 133.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_134" href="#FNanchor_134" class="label">[134]</a> -Journal de Physique, tom. xliii. 323.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_135" href="#FNanchor_135" class="label">[135]</a> -That is, alumn containing sulphate of potash.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_136" href="#FNanchor_136" class="label">[136]</a> -The production of ammoniac in this process was observed by -Kirwan and Austin.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_137" href="#FNanchor_137" class="label">[137]</a> -Solution of sulphure of strontian, or barytes, should be used. During -the conversion of nitrous gas into nitrous oxide by those bodies, -a thin film is deposited on the surface of the solution. This film -examined, is found to consist of sulphur and sulphate. Possibly the -nitrous gas is wholly decomposed by the hydrogene of the sulphurated -hydrogene in the solution, whilst the sulphate is produced from water -decompounded by the sulphur to form more gas for the saturation of the -hydro-sulphure.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_138" href="#FNanchor_138" class="label">[138]</a> -As was first observed by Priestley and Austin, and as I -have proved by many experiments.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_139" href="#FNanchor_139" class="label">[139]</a> -As I have found by experiment.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_140" href="#FNanchor_140" class="label">[140]</a> -As was observed by Milner. Nitrous gas passed over heated zinc, -or tin, I doubt not will be found converted into nitrous oxide.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_141" href="#FNanchor_141" class="label">[141]</a> -Annales de Chimie, xxxii. p. 3.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_142" href="#FNanchor_142" class="label">[142]</a> -The decomposition and recomposition of water, in this -process, are analogous to some of the phænomena observed -by the ingenious Mrs. Fulhame.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_143" href="#FNanchor_143" class="label">[143]</a> -From one of Dr. Priestley’s experiments, it appears that hydrogene gas -is sometimes disengaged during the solution of iron in very dilute -nitric acid by heat. This phænomenon has never occurred to me.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_144" href="#FNanchor_144" class="label">[144]</a> -As was discovered by Priestley, and the Dutch Chemists.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_145" href="#FNanchor_145" class="label">[145]</a> -Such as the leaves, bark, and wood, of trees.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_146" href="#FNanchor_146" class="label">[146]</a> -As I have observed after Priestley.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_147" href="#FNanchor_147" class="label">[147]</a> -As was discovered by Priestly.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_148" href="#FNanchor_148" class="label">[148]</a> -This deep color depended, in some measure, upon the nitro-muriatic -vapor suspended in it. I have since observed that it is more intense in -proportion as the heat employed for the production of the gas has been -stronger. The natural color of the peculiar gas is deep yellow.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_149" href="#FNanchor_149" class="label">[149]</a> -The decomposition of aëriform nitrous acid by mercury, was first noted -by Priestley; vol. iii. pag. 101. This decomposition I have often had -occasion to observe. In reading Humbolt’s paper on eudiometry, Annales -de Chimie, xxviii, pag. 150, I was not a little surprised to find that -he takes no notice of this fact. He seems to suppose that nitrous acid -can remain aëriform, and even be condensed, in contact with mercury, -without alteration. He says, “In mingling 100 parts of atmospheric -air with 100 of nitrous air, the air immediately became red, but all -the acid produced remained aëriform; and after eighteen hours some -<i>drops</i> only of acid were formed, which <i>swam</i> upon themercury.”</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_150" href="#FNanchor_150" class="label">[150]</a> -Lavoisier has said concerning aqua regia, “In solutions -of metals in this acid, as in all other acids, the metals are first -oxydated, by attracting a part of the oxygene from the compound -radical. This occasions the disengagement of a particular species of -gas not hitherto described, which may be called nitro-muriatic gas. -It has a very disagreeable smell, and is fatal to animal life when -respired; it attacks iron, and causes it to rust; it is absorbed in -considerable quantities by water.” Elem. Eng. 237.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_151" href="#FNanchor_151" class="label">[151]</a> -I have no doubt but that the gas procured from the solution of gold in -aqua regia, is analogous to that produced from platina.</p> - -<p>Some very uncommon circumstances are attendant on the solution of -platina:</p> - -<p>1st. The immense quantity of acid required for the solution of a minute -quantity of platina.</p> - -<p>2d. The great quantity of gas produced during the solution of this -minute quantity.</p> - -<p>3d. The intense red color of the solution, and its perfectly acid -properties after it ceases to act upon the metal.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_152" href="#FNanchor_152" class="label">[152]</a> -For if nitrous oxide had been formed, it would have been -decomposed by the hydrogene.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_153" href="#FNanchor_153" class="label">[153]</a> -Experiments and observations, vol. ii. pag. 81.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_154" href="#FNanchor_154" class="label">[154]</a> -The experiments of Berthollet have clearly proved the -perfect acidity of this substance.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_155" href="#FNanchor_155" class="label">[155]</a> -The Dutch chemists have asserted, that mixture with ammoniac prevents -the absorption of nitrous oxide by water, either wholly or partially. -Journal de Physique, t. xliii. part ii. pag. 327. It is difficult to -account for their mistake.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_156" href="#FNanchor_156" class="label">[156]</a> -Sulphureous acid saturates more potash than sulphuric acid, so that -most probably during the conversion of sulphite of potash into -sulphate, portions of sulphureous acid are disengaged.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_157" href="#FNanchor_157" class="label">[157]</a> -Hence we learn that sulphite of potash, when strongly heated, does not -decompose nitrous oxide, even in the <i>nascent state</i>.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_158" href="#FNanchor_158" class="label">[158]</a> -See the excellent memoir of Fourcroy and Vauquelin on the sulphureous -acid, and its combinations. Annales de Chimie, ii, 54. Or Nicholson’s -Phil. Journal, vol. i, pag. 313.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_159" href="#FNanchor_159" class="label">[159]</a> -Unless the sum of affinity of the potash, oil, nitrous oxide, and -earths, should be inch as to enable the nitrous oxide to combine with -the earth, whilst the oil and alkali remained in combination, & c.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_160" href="#FNanchor_160" class="label">[160]</a> -For when a little of the mixed salt was introduced into a solution -of sulphurated hydrogene, globules of gas were given out during the -solution.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_161" href="#FNanchor_161" class="label">[161]</a> -Carbonate of ammoniac formed at a high temperature, containing near -60 per cent alkali, and capable of combining with small quantities of -acids without giving out its carbonic acid. Of this salt a particular -account will be given in the experiments on the ammoniacal salts, which -I have often mentioned in the course of this work.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_162" href="#FNanchor_162" class="label">[162]</a> -It may not be amiss to mention some appearances taking place in the -decomposition of nitrous gas by sulphurated hydrogene, though it is -useless to theorise concerning them. The sulphur deposited is at -first yellow; as the process proceeds, it becomes white, and in some -instances I have suspected a diminution of it.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_163" href="#FNanchor_163" class="label">[163]</a> -Predisposing affinity, the existence of which at first consideration it -is difficult to admit, may be easily accounted for by <i>supposing</i> -the attractions of the simple principles of compound substances. And -this doctrine will apply in all instances where the constitution of -bodies is known. Predisposing affinity ought not to be considered as -the affinity of <i>non-existing</i> bodies for each other; but as the -mutual affinity of their simple principles, disposing them to assume -new arrangements.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_164" href="#FNanchor_164" class="label">[164]</a> -See the above mentioned elaborate memoir of Fourcroy and Vauquelin.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_165" href="#FNanchor_165" class="label">[165]</a> -The different persons who have respired nitrous oxide -have, as will be seen hereafter, given different accounts of the -taste; the greater number have called it sweet, some metallic. One -of my friends, in a letter to me dated Nov. 13, 1799, containing a -detail of some experiments made on the respiration of nitrous oxide, -at Birmingham, denotes the taste of it by the term “sweetish faintly -acidulous.” To me the taste both of the gas and of its solution in -water, has always appeared faintly sweetish.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_166" href="#FNanchor_166" class="label">[166]</a> -Section 2.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_167" href="#FNanchor_167" class="label">[167]</a> -Vol. ii. pag. 91.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_168" href="#FNanchor_168" class="label">[168]</a> -Journal de Physique, tom. xliii, part ii. pag. 330. They effected -the same change by passing it through a heated tube. Dr. Priestley -had published an account of similar experiments more than two years before.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_169" href="#FNanchor_169" class="label">[169]</a> -On the one hand, it decomposes ammoniac into hydrogene and nitrogene, -whilst on the other, it converts free oxygene and nitrogene into -nitrous acid. It likewise converts nitrous gas into nitrous acid and -nitrogene. Till we are more accurately acquainted with the nature of -heat, light, and electricity, we shall probably be unable to explain -these phænomena.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_170" href="#FNanchor_170" class="label">[170]</a> -Vol. ii. pag. 83.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_171" href="#FNanchor_171" class="label">[171]</a> -Journal de Physique, tom. xliii. part 2, pag. 331. They supposed it -to consist of about 37,5 oxygene, and 62,5 nitrogene. The nearness of -this account to the truth is singular, when we consider that they were -neither acquainted with the specific gravity of nitrous oxide, nor with -the production of nitrous acid in this experiment.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_172" href="#FNanchor_172" class="label">[172]</a> -Experiments on the detonation of nitrous oxide with phosphorus in this -way require great attention. The detonating jar should be very conical; -the nitrous oxide employed should never equal more than one eighth of -the capacity of the jar. The wire for the inflammation must be very -thick, and curved so as to be easily introduced into the jar. When -ignited, it must be instantaneously passed through the heated mercury -into the jar.</p> - -<p>Perhaps the electric spark might be advantageously applied for -detonating phosphoric vapor with nitrous oxide.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_173" href="#FNanchor_173" class="label">[173]</a> -It will be seen hereafter that these bodies are easily -inflamed in nitrous oxide.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_174" href="#FNanchor_174" class="label">[174]</a> -Phosphorus burnt feebly with a white flame in a mixture of -4 nitrogene and 1 nitrous oxide.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_175" href="#FNanchor_175" class="label">[175]</a> -Journal de Physique, xliii. 328.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_176" href="#FNanchor_176" class="label">[176]</a> -In this experiment, as in the last, dense white vapor was produced.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_177" href="#FNanchor_177" class="label">[177]</a> -<a href="#RI_DIII_02">Res. I. Div. III. S. II.</a></p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_178" href="#FNanchor_178" class="label">[178]</a> -Journal de Physique, xliii. 334.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_179" href="#FNanchor_179" class="label">[179]</a> -As is proved by the decomposition of oxide of iron and -sulphuric acid by charcoal, at that temperature.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_180" href="#FNanchor_180" class="label">[180]</a> -Hydrogene at or about the red heat, appears to attract oxygene stronger -than phosphorus. See Dr. Priestley’s experiments, vol. i. page 262.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_181" href="#FNanchor_181" class="label">[181]</a> -That attraction must be called chemical, which enables bodies of -different specific gravities to unite in such a manner as to produce a -compound, in every part of which the constituents are found in the same -proportions to each other. Atmospheric air, examined after having been -at perfect rest in closed vessels, for a great length of time, contains -in every part the same proportions of oxygene and nitrogene; whereas -if no affinity existed between these principles, following the laws -of specific gravity, they ought to separate; the oxygene forming the -inferior, the nitrogene the superior stratum.</p> - -<p>The supposition of the <i>chemical</i> composition of atmospheric air, -has been advanced by many philosophers. The two first evidences have -been often noticed.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_182" href="#FNanchor_182" class="label">[182]</a> -For it is unalterable by those bodies which are capable -of attracting oxygene from nitrous gas and nitrous acid, -at common temperatures.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_183" href="#FNanchor_183" class="label">[183]</a> -See the curious experiments of Rosier, Journal de Physique, 1786, -vol. 1, pag. 419.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_184" href="#FNanchor_184" class="label">[184]</a> -As appears from the experiments of Dr. Beddoes; likewise -those of Mr. Watt.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_185" href="#FNanchor_185" class="label">[185]</a> -As appears from the experiments of Lavoisier and Dr. Beddoes; -and as will be seen hereafter.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_186" href="#FNanchor_186" class="label">[186]</a> -The colour of common venous blood, examined in this way, resembles that -of the paint called by colour-men red ochre; that of blood saturated -with nitrous oxide, approaches to the tinge of lake.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_187" href="#FNanchor_187" class="label">[187]</a> -Small birds suffer much from cold when introduced into gases through -water. In this experiment, the goldfinch was immediately inserted -into a large mouthed phial, filled with the gases, and opened in the atmosphere.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_188" href="#FNanchor_188" class="label">[188]</a> -I use the popular name. This fish is very common in every part of -England; it is nearly of the same size and color as the minnow, and is -distinguished from it by two small bony excresences at the origin of -the belly. It is extremely susceptible.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_189" href="#FNanchor_189" class="label">[189]</a> -A priori I expected that fishes, like amphibious animals would -have been very quickly destroyed by the action of nitrous oxide.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_190" href="#FNanchor_190" class="label">[190]</a> -The hydrocarbonate employed, was procured from alcohol, -by means of sulphuric acid. This gas contains more carbon, -than hydrocarbonate from water and charcoal.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_191" href="#FNanchor_191" class="label">[191]</a> -The curious fact of the reddening of venous blood by -hydrocarbonate, was discovered by Dr. Beddoes.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_192" href="#FNanchor_192" class="label">[192]</a> -By lungs, I mean in this place, all the internal organs of respiration.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_193" href="#FNanchor_193" class="label">[193]</a> -Because these products are formed during the respiration -of common air.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_194" href="#FNanchor_194" class="label">[194]</a> -Annales de Chimie, vol. 1, page 279.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_195" href="#FNanchor_195" class="label">[195]</a> -This is only an imperfect approximation; the ratio of the increase of -expansibility of gases to the increase of temperature, has not yet been -ascertained. It is probable that the expansibility of gases is altered -by their mixture.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_196" href="#FNanchor_196" class="label">[196]</a> -For there is no reason to suppose the production of nitrogene.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_197" href="#FNanchor_197" class="label">[197]</a> -This capacity is most probably below the medium, my chest is narrow, -measuring in circumference, but 29 inches, and my neck rather long and -slender.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_198" href="#FNanchor_198" class="label">[198]</a> -Dr. Goodwyn in his excellent work on the connexion of life with -respiration, has detailed some experiments on the capacity of the lungs -after natural expiration. He makes the medium capacity about 109 cubic -inches, which agrees very well with my estimation.—page 27.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_199" href="#FNanchor_199" class="label">[199]</a> -The oxygene as we have before noticed, most probably -wholly existed in the residual gas.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_200" href="#FNanchor_200" class="label">[200]</a> -When they are agitated, a greater proportion of nitrous gas is -absorbed, condensed in the nitric acid by the water; and to find the -oxygene,</p> - -<table class="fontsize_120" border="0" cellspacing="0" summary=" " cellpadding="0" > - <tbody><tr> - <td class="tdc"> </td> - <td class="tdc">(50 - <i>m</i>)</td> - <td class="tdc">(50 - <i>m</i>)</td> - </tr><tr> - <td class="tdc"><i>x</i> =</td> - <td class="tdc"> ———— or </td> - <td class="tdc">————</td> - </tr><tr> - <td class="tdc"> </td> - <td class="tdc">(3,4)</td> - <td class="tdc">(3,5)</td> - </tr> - </tbody> -</table> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_201" href="#FNanchor_201" class="label">[201]</a> -The diminution of air by single inspirations, was -particularly noticed by Dr. Goodwyn.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_202" href="#FNanchor_202" class="label">[202]</a> -Dr. Priestley found that it likewise became florid at the surface when -covered by milk; but that it underwent little or no alteration of color -under water and most other fluids.—Vol. 3. p. 372.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_203" href="#FNanchor_203" class="label">[203]</a> -There are many analogous decompositions. Dr. Priestley noticed (and -I have often made the observation) that green oxide of iron, or the -precipitate from pale green sulphate of iron by caustic alkali, became -red at the surface, when covered by a thick stratum of water. In my -experiments on the green muriate and sulphate of iron, I observed that -part of some dark oxide of iron which was at the bottom of a trough -of water 9 inches deep, became red at the surface nearly in the same -time as another portion of the same precipitation that was exposed to -the atmosphere. This oxygenation must depend upon the decomposition of -atmospheric air constantly dissolved by the water.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_204" href="#FNanchor_204" class="label">[204]</a> -Dr. Mitchill attempted to prove from some phænomena connected with -contagious diseases, that dephlogisticated nitrous gas which he -called oxide of septon, was the principle of contagion, and capable -of producing the most terrible effects when respired by animals in -the minutest quantities or even when applied to the skin or muscular fibre.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_205" href="#FNanchor_205" class="label">[205]</a> -I did not attempt to experiment upon animals, because they die nearly -in equal times in non-respirable gases, and gases incapable of -supporting life and possessed of no action on the venous blood.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_206" href="#FNanchor_206" class="label">[206]</a> -Dr. Beddoes has given some account of this experiment, in his Notice -of some observations made at the Medical Pneumatic Institution. It was -noticed in Mr. Nicholson’s Phil. Journal for May 1799.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_207" href="#FNanchor_207" class="label">[207]</a> -Mild physical pleasure is perhaps always destructive to action. Almost -all our powerful voluntary actions, arise either from hope, fear, or -desire; and the most powerful from desire, which is an emotion produced -by the coalescence of hope or ideal pleasure with physical pain.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_208" href="#FNanchor_208" class="label">[208]</a> -Pure hydrogene has been often respired by different Philosophers, -particularly by Scheele, Fontana, and the adventurous and unfortunate Rosier.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_209" href="#FNanchor_209" class="label">[209]</a> -I believe it had never been breathed before by any -individual, in a state so little diluted.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_210" href="#FNanchor_210" class="label">[210]</a> -I ought to observe, that between eight and ten, I took by -the advice of Dr. Beddoes, two or three doses of diluted nitric acid.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_211" href="#FNanchor_211" class="label">[211]</a> -By whatever cause the exhaustion of organs is produced, pain is almost -uniformly connected with their returning health. Pain is rarely ever -perceived in limbs debilitated by fatigue till after they have been -for some hours at rest. Pain is uniformly connected with the recovery -from the debility induced by typhus, often with the recovery from that -produced by the stimulation of opium and alcohol.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_212" href="#FNanchor_212" class="label">[212]</a> -Carbonic acid is produced in this way in a high state of -purity, and with great readiness.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_213" href="#FNanchor_213" class="label">[213]</a> -Carbonic acid possesses no action on arterial blood. Hence perhaps, its -slight effects when breathed mingled with large quantities of common -air. Its effects are very marked upon venous blood! If it were thrown -forcibly into the lungs of animals, the momentary application of it to -the pulmonary venous blood would probably destroy life.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_214" href="#FNanchor_214" class="label">[214]</a> -In a conversation with Mr. Watt, relating to the powers of gases, -that excellent philosopher told me he had for some time entertained -a suspicion, that the effects attributed to oxygene produced from -manganese by heat, in some measure depended upon nitrous acid suspended -in the gas, formed during ignition by the union of some of the oxygene -of the manganese with nitrogene likewise condensed in it.</p> - -<p>In the course of experiments on nitrous acid, detailed in <a href="#RES_I">Research I</a>. -made in September, October, and December, 1799, I several times -experienced a severe oppression on the chest and difficulty of -respiration, not unanalogous to that produced by oxygene, but much more -violent, from breathing an atmosphere loaded with nitrous acid vapour. -This fact seemed to confirm Mr. Watt’s suspicion. I confess, however, -that I have never been able to detect any smell of nitrous acid, either -by means of my own organs or those of others, during the production -of oxygene; when the gas is suffered to pass into the atmosphere. The -oxygene breathed in the experiments detailed in the text, had been for -some days in contact with water.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_215" href="#FNanchor_215" class="label">[215]</a> -In the same manner as the debility from intoxication by -two bottles of wine is increased by a third.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_216" href="#FNanchor_216" class="label">[216]</a> -I ought to observe that my usual drink is water, that I had been little -accustomed to take wine or spirits, and had never been compleatly -intoxicated but once before in the course of my life. This will account -for the powerful effects of a single bottle of wine.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_217" href="#FNanchor_217" class="label">[217]</a> -The plan of this box was communicated by Mr. Watt. An account of -it will be detailed in the <i>Researches</i>.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_218" href="#FNanchor_218" class="label">[218]</a> -The nitrous oxide was too diluted to act much; it was -mingled with near 32 times its bulk of atmospheric air.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_219" href="#FNanchor_219" class="label">[219]</a> -In all these experiments after the first minute, my cheeks -became purple.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_220" href="#FNanchor_220" class="label">[220]</a> -Physical pleasure and pain generally occur connected with a compound -impression, i. e. an organ and some object. When the idea left by the -compound impression, is called up by being linked accidentally to some -other idea or impression, no recurrence, or the slightest possible, -of the pleasure or pain in any form will take place. But when the -compound impression itself exists <i>without</i> the physical pleasure -or pain, it will awaken ideal or intellectual pleasure or pain, i. e. -hope or fear. So that physical pleasure and pain are to hope and fear, -what impressions are to ideas. For instance, assuming no accidental -association, the child does not fear the fire before he is burnt. When -he puts his finger to the fire he feels the physical pain of burning, -which is connected with a visible compound impression, the fire and his -finger. Now when the compound idea of the fire and his finger, left by -the compound impression are called up by his mother, saying, “<i>You -have burnt your finger</i>,” nothing like fear or the pain of burning -is connected with it. But when the finger is brought near the fire, i. -e. when the compound impression again exists, the ideal pain of burning -or the passion of fear is awakened, and it becomes connected with those -very actions which removed the finger from the fire.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_221" href="#FNanchor_221" class="label">[221]</a> -Notice of some Observations made at the Medical Pneumatic Institution.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_222" href="#FNanchor_222" class="label">[222]</a> -In some of these experiments, hearing was rendered more acute.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_223" href="#FNanchor_223" class="label">[223]</a> -Dr. Mitchill (an American Chemist) has erroneously supposed its full -admission to the lungs, in its concentrated state, to be incompatible -with animal life, and that in a more diluted form it operates as a -principal agent in the production of contagious diseases, &c. -This gratuitous position is thus unqualifiedly affirmed. “If a full -inspiration of gaseous oxyd be made, there will be a sudden extinction -of life; and this accordingly accounts for the fact related by Russel -(History of Aleppo, p. 232.) and confirmed by other observers, of many -persons falling down dead suddenly, when struck with the contagion of -the plague.”</p> - -<p>Vide Remarks on the Gaseous Oxyd of Azote, by Samuel Latham Mitchill, M. D.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_224" href="#FNanchor_224" class="label">[224]</a> -In the former experiments, Mr. Southey generally respired -six quarts, now he is unable to consume two.</p> - -<p>In an experiment made since this paper was drawn up, the effect was -rather pleasurable.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_225" href="#FNanchor_225" class="label">[225]</a> -The doses in these experiments were from five to seven quarts.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_226" href="#FNanchor_226" class="label">[226]</a> -Of the facts on which Brown founded his law of indirect debility, no -prudent man will lose sight either in practising or studying medicine. -They are incontrovertible.—And our new facts may doubtless be -conciliated to the Brunonian doctrine.</p> - -<p>But to suppose that the expenditure of a quality or a substance or a -spirit, and its renewal or accumulation are the general principles of -animal phænomena, seems to me a grievous and baneful error. I believe -it often happens that excitement and excitability increase, and that -they oftener decrease together;—In short, without generalizing in a -manner, of which Brown and similar theorists had no conception, our -notions of the living world will in my opinion, continue to be as -confused as the elements are said to have been in chaos. On some future -occasion, I may presume to point out the region through which I -imagine the path to wind, that will lead the observers of some distant -generation to a point, whence they may enjoy a view of the subtle, busy -and intricate movements of the organic creation as clear as Newton -obtained of the movements of the heavenly masses.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_227" href="#FNanchor_227" class="label">[227]</a> -After writing this, I was present when an invalid, in whose foot the -gout, after much wandering, had at last fixed, breathed 12 quarts of -oxygene gas. While breathing, he eagerly pointed to the inflamed leg; -and afterwards said he had felt in it a new sensation, somewhat like -tension.—I never had seen oxygene respired where there was so -much local inflammation.</p> - -<p>June 18. After four quarts of oxygene with 6 of nitrous oxide and -then 6 of nitrous oxide alone, violent itching of the wounds made by -the leech; and redness and tumour.—Both had healed, and I did not -expect to feel any thing more from them.—I tried this again with two -doses of nitrous oxide—The yellow halo round one wound changed to -crimson, and there was so much stinging and swelling that I feared -suppuration.—Absorption here was rapid.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_228" href="#FNanchor_228" class="label">[228]</a> -See Dr. Beddoes’s <i>Considerations</i>, <i>part</i> 1. <i>page</i> -26. His observations in the note in the last section, will likewise -apply here.—Is not healthy living action dependant upon a certain -equilibrium between the principles supplied to the blood by the -pulmonary veins from respiration and by the lymphatics from absorption? -Does not sensibility more immediately depend upon respiration? Deprive -an animal under stimulation, of air, and it instantly dies; probably if -absorption could be prevented, it would likewise speedily die. It would -be curious to try whether intoxication from fermented liquors cannot be -prevented by breathing during their operation, an atmosphere deprived -of part of its oxygene.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_229" href="#FNanchor_229" class="label">[229]</a> -Sublime emotion with regard to natural objects, is generally produced -by the connection of the pleasure of beauty with the passion of fear.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_230" href="#FNanchor_230" class="label">[230]</a> -The immortal <span class="smcap">Hartley</span> has demonstrated that -all our motions are originally automatic, and generally produced by the -action of tangible things on the muscular fibre.</p> - -<p>The common actions of adults may be distinguished into two kinds; -voluntary actions, and mixed automatic actions. The first are -produced by ideas, or by ideas connected with passions. The second by -impression, or by pleasure and pain.</p> - -<p>In voluntary action, regular associations of ideas and muscular motions -exist: as when a chemist performs a pre-conceived experiment.</p> - -<p>In mixed automatic actions, the simple motions produced by impression -are connected with series of motions formerly voluntary, but now -produced without the intervention of ideas: as when a person -accustomed to play on the harpsichord, from accidentally striking -a key, is induced to perform the series of motions which produce a -well-remembered tune.</p> - -<p>Evidently the muscular actions produced by nitrous oxide are mixed -automatic motions.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_231" href="#FNanchor_231" class="label">[231]</a> -See R. IV. Div. I. page 478.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_232" href="#FNanchor_232" class="label">[232]</a> -R. IV. Div. I. page 467.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_233" href="#FNanchor_233" class="label">[233]</a> -That of Brown modified by his disciples.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_234" href="#FNanchor_234" class="label">[234]</a> -Supposing the increase or diminution of living action when produced -by different agents, uniform, similar and differing only in degree; -it would follow, that certain mixtures of hydrocarbonate and nitrous -oxide, or hydrogene and nitrous oxide, ought to be capable of -supporting the life of animals for a much longer time than pure nitrous -oxide. From the experiments in <a href="#RIII_DIV_I">Res. III. Div. I</a>. -it appears however, that this is not the case.</p> - -<p>It would seem, that in life, a variety of different corpuscular changes -are capable of producing phænomena apparently similar; so that in the -science of living action, we are incapable of reasoning concerning -causes from effects.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_235" href="#FNanchor_235" class="label">[235]</a> -Annales de Chimie, 100; and Mr. Tilloch’s Phil. Magazine. 24.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_236" href="#FNanchor_236" class="label">[236]</a> -I regret much that I could not procure Dr. Menzies’s observations on -Respiration, while I was making the experiments on the capacity of the -lungs: they would probably have saved me some labor.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_237" href="#FNanchor_237" class="label">[237]</a> -If loosely combined carbon exists in venous blood, hydrogene may -probably dissolve a portion of it when respired and become slightly -carbonated. At least there is as much probability in the supposition -that carbon in loose affinity may combine with hydrogene at 98° as that -it may combine with oxygene.</p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_238" href="#FNanchor_238" class="label">[238]</a> -Dr. <span class="smcap">Beddoes</span> has since favoured me with -the following account of these facts.</p> - -<p>“Mr. Humboldt (ueber die gereizte Faser I. 473, 1797) quotes part -of a letter from Dr. Ash, in which it is said that <i>if two finely -polished plates of homogeneous zinc be moistened and laid together, -little effect follows—but if zinc and silver be tried in the same way, -the whole surface of the silver will be covered with oxydated zinc. -Lead and quicksilver act as powerfully on each other, and so do iron -and copper.</i>—Mr. Humboldt (p. 474) says that, in repeating this -experiment, he saw air-bubbles ascend, which he supposes to have been -hydrogene gas from the decomposition of water—When he placed zinc -simply on moist glass, the same phænomena took place, but more slowly -and later. The quantity of oxyd of zinc upon the glass alone was in 20 -hours to that on the silver as one to three.</p> - -<p>In a very ingenious but obscurely written tract by Mr. Ritter, -entitled, <i>Evidence that the galvanic action exists in organic -nature</i>, <i>8vo. Jena, 1800</i>—The author observes, that the care -of Dr. Ash and Mr. Humboldt that the metals should touch each other -in as many points as possible was superfluous, even if we could grant -that two metallic plates might be made by polishing, to touch in a -number of points. To shew that it was sufficient if by touching in one -point only they should form a compleat galvanic circle, he dropped a -single drop of distilled water upon the bust of a large silver coin. -A piece of pure zinc was placed with its one end on the edge of the -coin, while the other was supported by a bit of glass. The drop of -water was neither in contact with the glass nor with the point at which -the metals touched. The materials were left in this situation for four -hours at the temperature of 68°. On taking them apart, the water had -become quite milky and had half disappeared; and Mr. Ritter actually -separated a quantity of white oxide that had been produced in the experiment.</p> - -<p>The pieces of metal were cleaned and laid together in the same manner, -only that now a piece of paper was put between the metals at their -former point of contact. In four hours first, and afterwards in ten, a -faint ring of oxide only had been produced of which the quantity could -not be estimated, nor could it be separated. In this case, the zinc -had scarce lost any thing of its splendour; in the former it had been -corroded. In many repetitions of the experiment, he found that far more -oxide was formed when the metals touched, than when they were separated -to the slightest distance by an insolating body, even air.</p> - -<p>On exposing these apparatuses with somewhat more water to a -considerable heat for four minutes, the water in the interrupted circle -continued quite clear, while that in the other had become milk-white.</p> - -<p>The same phænomena were presented by other pairs of metals in a degree -proportional to their galvanic activity; viz. by zinc and molybdæna, -zinc and bismuth, zinc and copper, as also with tin and silver, tin -and molybdæna, and lead and silver. The experiment with tin was -particularly decisive, for when in contact with no other metal it was -scarcely at all oxydated by water, though oxydation took place when -tin was brought into contact with silver, and both were connected at -the other end by a drop of water—What therefore took place in Dr. -Ash’s experiment, arose from an aggregation of galvanic circles of -different forms.</p> - -<p>By the foregoing experiments, concludes Mr. Ritter, which though -capable of the most various modifications, uniformly coincide in -their main result, it is abundantly proved that <i>galvanic circles -can be formed of merely inorganic bodies, by whose completion there -is produced an action which ceases when the circle is opened</i>. The -manner in which this has been shewn, proves also that <i>this action -can effectuate sensible modifications in organic bodies</i>; and the -process by which these modifications have been effected, made it -evident that they <i>were not consequences of a momentary action of -the circle, but of an action that is kept up while the circle remains -entire</i>; for the process which brought this action under the -cognizance of the senses went on, while the circle was unbroken, and -its figure not brought back to that of a line.</p> - -<p>It is scarce necessary to observe that the experiments here quoted, are -far from being the only ones on which the above conclusions rest.”</p> - -<p class="author"><i>T. B.</i></p> -</div> - -<div class="footnote"><p class="no-indent"> -<a id="Footnote_239" href="#FNanchor_239" class="label">[239]</a> -Possibly a ratio exists between the solubility of gases in water, and -the solubility of water in gases. It is probable from Mr. Wm. Henry’s -curious experiments on the muriatic acid, that the absolute quantity -of water in <i>many</i> gases, may be ascertained by means of its -decomposition by the electric spark.</p> -</div> -</div> - -<div class="transnote bbox space-above2"> -<p class="f120 space-above1">Transcriber’s Notes:</p> -<hr class="r5" /> -<p class="indent">The cover image was created by the transcriber, and is in the public domain.</p> -<p class="indent">Ancient spellings were not corrected.</p> -<p class="indent">Typographical and punctuation errors have been silently corrected.</p> -<p class="indent">The text usually uses a comma to designate a decimal point, although - a period is used in some instances.</p> -<p class="indent">The changes mentioned in the ERRATA have been applied to the text.</p> -</div> - -<div style='display:block; margin-top:4em'>*** END OF THE PROJECT GUTENBERG EBOOK RESEARCHES CHEMICAL AND PHILOSOPHICAL ***</div> -<div style='text-align:left'> - -<div style='display:block; margin:1em 0'> -Updated editions will replace the previous one—the old editions will -be renamed. -</div> - -<div style='display:block; margin:1em 0'> -Creating the works from print editions not protected by U.S. copyright -law means that no one owns a United States copyright in these works, -so the Foundation (and you!) can copy and distribute it in the United -States without permission and without paying copyright -royalties. 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