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diff --git a/22620-8.txt b/22620-8.txt new file mode 100644 index 0000000..ec3f626 --- /dev/null +++ b/22620-8.txt @@ -0,0 +1,7371 @@ +Project Gutenberg's Researches on Cellulose, by C. F. Cross and E. J. Bevan + +This eBook is for the use of anyone anywhere 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 www.gutenberg.org + + +Title: Researches on Cellulose + 1895-1900 + +Author: C. F. Cross + E. J. Bevan + +Release Date: September 16, 2007 [EBook #22620] + +Language: English + +Character set encoding: ISO-8859-1 + +*** START OF THIS PROJECT GUTENBERG EBOOK RESEARCHES ON CELLULOSE *** + + + + +Produced by Juliet Sutherland, Josephine Paolucci and the +Online Distributed Proofreading Team at http://www.pgdp.net. +(This file was produced from images generously made +available by The Internet Archive/Million Book Project). + + + + + + + + + + +RESEARCHES ON CELLULOSE + +1895-1900 + +BY + +CROSS & BEVAN + +(C. F. CROSS AND E. J. BEVAN) + + +_SECOND EDITION_ + + +LONGMANS, GREEN, AND CO. +39 PATERNOSTER ROW, LONDON +NEW YORK, BOMBAY, AND CALCUTTA + +1907 + +All rights reserved + + * * * * * + +Transcriber's note: + +For Text: A word surrounded by a cedilla such as ~this~ signifies that +the word is bolded in the text. A word surrounded by underscores like +_this_ signifies the word is italics in the text. The italic and bold +markup for single italized letters (such as variables in equations) and +"foreign" abbreviations are deleted for easier reading. + +For numbers and equations: Parentheses have been added to clarify +fractions. Underscores before bracketed numbers in equations denote a +subscript. Superscripts are designated with a caret and brackets, e.g. +11.1^{3} is 11.1 to the third power. Greek letters in equations are +translated to their English version. + +The sections in the Table of Contents are not used in the actual text. +They have been added for clarity. + +Minor typos have been corrected and footnotes moved to the end of the +sections + + * * * * * + + + + + +PREFACE TO SECOND EDITION + + +This edition is a _reprint_ of the first in response to a continuous +demand for the book. The matter, consisting as it does largely of +records, does not call for any revision, and, as a contribution to the +development of theory, any particular interest which it has is +associated with the date at which it was written. + +The volume which has since appeared is the sequel, and aims at an +exposition of the subject "to date". + + + + +PREFACE + + +This volume, which is intended as a supplement to the work which we +published in 1895, gives a brief account of researches which have been +subsequently published, as well as of certain of our own investigations, +the results of which are now for the first time recorded. + +We have not attempted to give the subject-matter the form of a connected +record. The contributions to the study of 'Cellulose' which are noticed +are spread over a large area, are mostly 'sectional' in their aim, and +the only cohesion which we can give them is that of classifying them +according to the plan of our original work. Their subject-matter is +reproduced in the form of a _précis_, as much condensed as possible; of +the more important papers the original title is given. In all cases we +have endeavoured to reproduce the Author's main conclusions, and in most +cases without comment or criticism. + +Specialists will note that the basis of investigation is still in a +great measure empirical; and of this the most obvious criterion is the +confusion attaching to the use of the very word 'Cellulose.' This is due +to various causes, one of which is the curious specialisation of the +term in Germany as the equivalent of 'wood cellulose.' The restriction +of this general or group term has had an influence even in scientific +circles. Another influence preventing the recognition of the obvious +and, as we think, inevitable basis of classification of the 'celluloses' +is the empiricism of the methods of agricultural chemistry, which as +regards cellulose are so far chiefly concerned with its negative +characteristics and the analytical determination of the indigestible +residue of fodder plants. Physiologists, again, have their own views and +methods in dealing with cellulose, and have hitherto had but little +regard to the work of the chemist in differentiating and classifying the +celluloses on a systematic basis. There are many sides to the subject, +and it is only by a sustained effort towards centralisation that the +general recognition of a systematic basis can be secured. + +We may, we hope usefully, direct attention to the conspicuous neglect of +the subject in this country. To the matter of the present volume, +excluding our own investigations, there are but two contributions from +English laboratories. We invite the younger generation of students of +chemistry to measure the probability of finding a working career in +connection with the cellulose industries. They will not find this +invitation in the treatment accorded to the subject in text-books and +lectures. It is probable, indeed, that the impression produced by their +studies is that the industries in coal-tar products largely exceed in +importance those of which the carbohydrates are the basis; whereas the +former are quite insignificant by comparison. A little reflection will +prove that cellulose, starch, and sugar are of vast industrial moment in +the order in which they are mentioned. If it is an open question to +what extent science follows industry, or _vice versa_, it is not open to +doubt that scientific men, and especially chemists, are called in these +days to lead and follow where industrial evolution is most active. There +is ample evidence of activity and great expansion in the cellulose +industries, especially in those which involve the chemistry of the raw +material; and the present volume should serve to show that there is +rapid advance in the science of the subject. Hence our appeal to the +workers not to neglect those opportunities which belong to the days of +small beginnings. + +We have especially to acknowledge the services of Mr. J. F. BRIGGS in +investigations which are recorded on pp. 34-40 and pp. 125-133 of the +text. + + + + +CONTENTS + +THE MATTER OF THIS VOLUME MAY BE DIVIDED INTO THE FOLLOWING SECTIONS + + + PAGE + +INTRODUCTION--DEALING WITH THE SUBJECT IN GENERAL OUTLINE 1 + + +SECTION + +I. GENERAL CHEMISTRY OF THE TYPICAL COTTON CELLULOSE 13 + +II. SYNTHETICAL DERIVATIVES--SULPHOCARBONATES AND ESTERS 27 + +III. DECOMPOSITIONS OF CELLULOSE SUCH AS THROW LIGHT + ON THE PROBLEM OF ITS CONSTITUTION 67 + +IV. CELLULOSE GROUP, INCLUDING HEMICELLULOSES AND + TISSUE CONSTITUENTS OF FUNGI 97 + +V. FURFUROIDS, i.e. PENTOSANES AND FURFURAL-YIELDING + CONSTITUENTS GENERALLY 114 + +VI. THE LIGNOCELLULOSES 125 + +VII. PECTIC GROUP 152 + +VIII. INDUSTRIAL AND TECHNICAL. GENERAL REVIEW 155 + + +INDEX OF AUTHORS 177 + +INDEX OF SUBJECTS 178 + + + + +CELLULOSE + + + + +INTRODUCTION + + +In the period 1895-1900, which has elapsed since the original +publication of our work on 'Cellulose,' there have appeared a large +number of publications dealing with special points in the chemistry of +cellulose. So large has been the contribution of matter that it has been +considered opportune to pass it under review; and the present volume, +taking the form of a supplement to the original work, is designed to +incorporate this new matter and bring the subject as a whole to the +level to which it is thereby to be raised. Some of our critics in +reviewing the original work have pronounced it 'inchoate.' For this +there are some explanations inherent in the matter itself. It must be +remembered that every special province of the science has its systematic +beginning, and in that stage of evolution makes a temporary 'law unto +itself.' In the absence of a dominating theory or generalisation which, +when adopted, gives it an organic connection with the general advance of +the science, there is no other course than to classify the +subject-matter. Thus 'the carbohydrates' may be said to have been in the +inchoate condition, qualified by a certain classification, prior to the +pioneering investigations of Fischer. In attacking the already +accumulated and so far classified material from the point of view of a +dominating theory, he found not only that the material fell into +systematic order and grew rapidly under the stimulus of fruitful +investigation, but in turn contributed to the firmer establishment of +the theoretical views to which the subject owed its systematic new +birth. On the other hand, every chemist knows that it is only the +simpler of the carbohydrates which are so individualised as to be +connoted by a particular formula in the stereoisomeric system. Leaving +the monoses, there is even a doubt as to the constitution of cane sugar; +and the elements of uncertainty thicken as we approach the question of +the chemical structure of starch. This unique product of plant life has +a literature of its own, and how little of this is fully known to what +we may term the 'average chemist' is seen by the methods he will employ +for its quantitative estimation. In one particular review of our work +where we are taken to task for producing 'an aggravating book, inchoate +in the highest degree ... disfigured by an obscurity of diction which +must materially diminish its usefulness' ['Nature,' 1897, p. 241], the +author, who is a well-known and competent critic, makes use of the short +expression in regard to the more complex carbohydrates, 'Above cane +sugar, higher in the series, all is chaos,' and in reference to starch, +'the subject is still enshrouded in mystery.' This 'material' complexity +is at its maximum with the most complex members of the series, which are +the celluloses, and we think accounts in part for the impatience of our +critic. 'Obscurity of diction' is a personal quantity, and we must leave +that criticism to the fates. We find also that many workers whose +publications we notice in this present volume quite ignore the _plan_ of +the work, though they make use of its matter. We think it necessary to +restate this plan, which, we are satisfied, is systematic, and, in fact, +inevitable. Cellulose is in the first instance a _structure_, and the +anatomical relationships supply a certain basis of classification. Next, +it is known to us and is defined by the negative characteristics of +resistance to hydrolytic actions and oxidations. These are dealt with in +the order of their intensity. Next we have the more positive definition +by ultimate products of hydrolysis, so far as they are known, which +discloses more particularly the presence of a greater or less proportion +of furfural-yielding groups. Putting all these together as criteria of +function and composition we find they supply common or general dividing +lines, within which groups of these products are contained. The +classification is natural, and in that sense inevitable; and it not only +groups the physiological and chemical facts, but the industrial also. We +do not propose to argue the question whether the latter adds any cogency +to a scientific scheme. We are satisfied that it does, and we do not +find any necessity to exclude a particular set of phenomena from +consideration, because they involve 'commercial' factors. We have dealt +with this classification in the original work (p. 78), and we discuss +its essential basis in the present volume (p. 28) in connection with the +definition of a 'normal' cellulose. But the 'normal' cellulose is not +the only cellulose, any more than a primary alcohol or an aliphatic +alcohol are the only alcohols. This point is confused or ignored in +several of the recent contributions of investigators. It will suffice to +cite one of these in illustration. On p. 16 we give an account of an +investigation of the several methods of estimating cellulose, which is +full of valuable and interesting matter. The purpose of the author's +elaborate comparative study is to decide which has the strongest claims +to be regarded as the 'standard' method. They appear to have a +preference for the method of Lange--viz. that of heating at high +temperatures (180°) with alkaline hydrates, but the investigation shows +that (as we had definitely stated in our original work, p. 214) this is +subject to large and variable errors. The adverse judgment of the +authors, we may point out, is entirely determined on the question of +aggregate weight or yield, and without reference to the ultimate +composition or constitution of the final product. None of the available +criteria are applied to the product to determine whether it is a +cellulose (anhydride) or a hydrate or a hydrolysed product. After these +alkali-fusion processes the method of chlorination is experimentally +reviewed and dismissed for the reason that the product retains +furfural-yielding groups, which is, from our point of view, a particular +recommendation, i.e. is evidence of the selective action of the chlorine +and subsequent hydrolysis upon the lignone group. As a matter of fact it +is the only method yet available for isolating the cellulose from a +lignocellulose by a treatment which is quantitatively to be accounted +for in every detail of the reactions. It does not yield a 'normal' +cellulose, and this is the expression which, in our opinion, the authors +should have used. It should have been pointed out, moreover, that, as +the cellulose is separated from actual condensed combination with the +lignone groups, it may be expected to be obtained in a hydrated form, +and also not as a homogeneous substance like the normal cotton +cellulose. The product is a cellulose of the second group of the +classification. Another point in this investigation which we must +criticise is the ultimate selection of the Schulze method of prolonged +maceration with nitric acid and a chlorate, followed by suitable +hydrolysis of the non-cellulose derivatives to soluble products. Apart +from its exceptional inconvenience, rendering it quite impracticable in +laboratories which are concerned with the valuation of cellulosic raw +materials for industrial purposes, the attack of the reagent is complex +and ill-defined. This criticism we would make general by pointing out +that such processes quite ignore the specific characteristics of the +non-cellulose components of the compound celluloses. The second division +of the plan of our work was to define these constituents by bringing +together all that had been established concerning them. These groups are +widely divergent in chemical character, as are the compound celluloses +in function in the plant. Consequently there is for each a special +method of attack, and it is a reversion to pure empiricism to expect any +one treatment to act equally on the pectocelluloses, lignocelluloses, +and cutocelluloses. Processes of isolating cellulose are really more +strictly defined as methods of selective and regulated attack of the +groups with which they occur, combined or mixed. A chemist familiar with +such types as rhea or ramie (pectocellulose), jute (lignocellulose), and +raffia (cutocellulose) knows exactly the specific treatment to apply to +each for isolating the cellulose, and must view with some surprise the +appearance at this date of such 'universal prescriptions' as the process +in question. + +The third division of our plan of arrangement comprised the synthetical +derivatives of the celluloses, the sulphocarbonates first, as peculiarly +characteristic, and then the esters, chiefly the acetates, benzoates, +and nitrates. To these, investigators appear to have devoted but little +attention, and the contribution of new matter in the present volume is +mainly the result of our own researches. It will appear from this work +that an exhaustive study of the cellulose esters promises to assist very +definitely in the study of constitutional problems. + +This brings us to the fourth and, to the theoretical chemist, the most +important aspect of the subject, the problem of the actual molecular +structure of the celluloses and compound celluloses. It is herein we are +of opinion that the subject makes a 'law unto itself.' If the +constitution of starch is shrouded in mystery and can only be vaguely +expressed by generalising a complex mass of statistics of its successive +hydrolyses, we can only still more vaguely guess at the distance which +separates us from a mental picture of the cellulose unit. We endeavour +to show by our later investigations that this problem merges into that +of the actual structure of cellulose in the mass. It is definitely +ascertained that a change in the molecule, or reacting unit, of a +cellulose, proportionately affects the structural properties of the +derived compounds, both sulphocarbonates and esters. This is at least an +indication that the properties of the visible aggregates are directly +related to the actual configuration of the chemical units. But it +appears that we are barred from the present discussion of such a problem +in absence of any theory of the solid state generally, but more +particularly of those forms of matter which are grouped together as +'colloids.' + +Cellulose is distinguished by its inherent constructive functions, and +these functions take effect in the plastic or colloidal condition of the +substance. These properties are equally conspicuous in the synthetical +derivatives of the compound. Without reference, therefore, to further +speculations, and not deterred by any apparent hopelessness of solving +so large a problem, it is clear that we have to exhaust this field by +exact measurements of all the constants which can be reduced to +numerical expression. It is most likely that the issue may conflict with +some of our current views of the molecular state which are largely drawn +from a study of the relatively dissociated forms of matter. But such +conflicts are only those of enlargement, and we anticipate that all +chemists look for an enlargement of the molecular horizon precisely in +those regions where the forces of cell-life manifest themselves. + +The _cellulose group_ has been further differentiated by later +investigations. The fibrous celluloses of which the typical members +receive important industrial applications, graduate by insensible stages +into the hemicelluloses which may be regarded as a well-established +sub-group. In considering their morphological and functional +relationships it is evident that the graduation accords with their +structure and the less permanent functions which they fulfil. They are +aggregates of monoses of the various types, chiefly mannose, galactose, +dextrose, &c., so far as they have been investigated. + +Closely connected with this group are the constituents of the tissues of +fungi. The recent researches of Winterstein and Gilson, which are noted +in this present volume, have established definitely that they contain a +nitrogenous group in intimate combination with a carbohydrate complex. +This group is closely related to chitin, yielding glucosamin and acetic +acid as products of ultimate hydrolysis. Special interest attaches to +these residues, as they are in a sense intermediate products between the +great groups of the carbohydrates and proteids (E. Fischer, Ber. 19, +1920), and their further investigation by physiological methods may be +expected to disclose a genetic connection. + +The _lignocelluloses_ have been further investigated. Certain new types +have been added, notably a soluble or 'pectic' form isolated from the +juice of the white currant (p. 152), and the pith-like wood of the +Æschynomene (p. 135). + +Further researches on the typical fibrous lignocellulose have given us a +basis for correcting some of the conclusions recorded in our original +work, and a study of the esters has thrown some light on the +constitution of the complex (p. 130). + +Of importance also is the identification of the hydroxyfurfurals as +constituents of the lignocelluloses generally, and the proof that the +characteristic colour-reactions with phenols (phloroglucinol) may be +ascribed to the presence of these compounds (p. 116). + +The _pectocelluloses_ have not been the subject of systematic chemical +investigation, but the researches of Gilson ('La Cristallisation de la +Cellulose et la Composition Chimique de la Membrane Cellulaire +Végétale,' 'La Revue,' 'La Cellule,' i. ix.) are an important +contribution to the natural history of cellulose, especially in relation +to the 'pectic' constituents of the parenchymatous celluloses. +Indirectly also the researches of Tollens on the 'pectins' have +contributed to the subject in correcting some of the views which have +had a text-book currency for a long period. These are dealt with on p. +151. The results establish that the pectins are rather the soluble +hydrated form of cellulosic aggregates in which acid groups may be +represented; but such groups are not to be regarded as essentially +characteristic of this class of compounds. + +~Furfural-yielding Substances~ (Furfuroids).--This group of plant products +has been, by later investigations, more definitely and exclusively +connected with the celluloses--i.e. with the more permanent of plant +tissues. From the characteristic property of yielding furfural, which +they have in common with the pentoses, they have been assumed to be the +anhydrides of these C_{5} sugars or pentosanes; but the direct evidence +for this assumption has been shown to be wanting. In regard to their +origin the indirect evidences which have accumulated all point to their +formation in the plant from hexoses. Of special interest, in its +bearings on this point, is the direct transformation of levulose into +furfural derivatives, which takes place under the action of condensing +agents. The most characteristic is that produced by the action of +anhydrous hydrobromic acid in presence of ether [Fenton], yielding a +brommethyl furfural + + C_{6}H_{12}O_{6} - 4H_{2}O + HBr = C_{5}H_{3}.O_{2}.CH_{2}Br + +with a Br atom in the methyl group. These researches of Fenton's appear +to us to have the most obvious and direct bearings upon the genetic +relationships of the plant furfuroids and not only _per se_. To give +them their full significance we must recall the later researches of +Brown and Morris, which establish that cane sugar is a primary or direct +product of assimilation, and that starch, which had been assumed to be a +species of universal _matière première_, is probably rather a general +reserve for the elaborating work of the plant. If now the aldose groups +tend to pass over into the starch form, representing a temporary +overflow product of the assimilating energy, it would appear that the +ketose or levulose groups are preferentially used up in the elaboration +of the permanent tissue. We must also take into consideration the +researches of Lobry de Bruyn showing the labile functions of the typical +CO group in both aldoses and hexoses, whence we may conclude that in the +plant-cell the transition from dextrose to levulose is a very simple and +often occurring process. + +We ourselves have contributed a link in this chain of evidence +connecting the furfuroids of the plant with levulose or other +keto-hexose. We have shown that the hydroxyfurfurals are constituents of +the lignocelluloses. The proportion present in the free state is small, +and it is not difficult to show that they are products of breakdown of +the lignone groups. If we assume that such groups are derived ultimately +from levulose, we have to account for the detachment of the methyl +group. This, however, is not difficult, and we need only call to mind +that the lignocelluloses are characterised by the presence of methoxy +groups and a residue which is directly and easily hydrolysed to acetic +acid. Moreover, the condensation need not be assumed to be a simple +dehydration with attendant rearrangement; it may very well be +accompanied or preceded by fixation of oxygen. Leaving out the +hypothetical discussion of minor variations, there is a marked +convergence of the evidence as to the main facts which establish the +general relationships of the furfuroid group. This group includes both +saturated and unsaturated or condensed compounds. The former are +constituents of celluloses, the latter of the lignone complex of the +lignocelluloses. + +The actual production of furfural by boiling with condensing acids is a +quantitative measure of only a portion, i.e. certain members of the +group. The hydroxyfurfurals, not being volatile, are not measured in +this way. By secondary reactions they may yield some furfural, but as +they are highly reactive compounds, and most readily condensed, they are +for the most part converted into complex 'tarry' products. Hence we have +no means, as yet, of estimating those tissue constituents which yield +hydroxyfurfurals; also we have no measure of the furfurane-rings +existing performed in such a condensed complex as lignone. But, chemists +having added in the last few years a large number of facts and +well-defined probabilities, it is clear that the further investigation +of the furfuroid group will take its stand upon a much more adequate +basis than heretofore. On the view of 'furfural-yielding' being +co-extensive with 'pentose or pentosane,' not only were a number of +important facts obscured or misinterpreted, but there was a barrenness +of suggestion of genetic relationships. As the group has been widened +very much beyond these limits, it is clear that if any group term or +designation is to be retained that of 'furfuroid' is 'neutral' in +character, and equally applicable to saturated substances of such widely +divergent chemical character as pentoses, hexosones, glycuronic acid, +and perhaps, most important of all, levulose itself, all of which are +susceptible of condensation to furfural or furfurane derivatives, as +well as to those unsaturated compounds, constituents of plant tissues +which are already furfurane derivatives. + +From the chemical point of view such terms are perhaps superfluous. But +physiological relationships have a significance of their own; and there +is a physiological or functional cohesion marking this group which +calls for recognition, at least for the time, and we therefore propose +to retain the term furfuroid.[1] + +~General Experimental Methods.~--In the investigation of the cellulose +group it is clear that methods of ultimate hydrolysis are of first +importance. None are so convenient as those which are based on the +action of sulphuric acid, more or less concentrated (H_{2}SO_{4}.3H_{2}O +- H_{2}SO_{4}H_{2}O). Such methods have been frequently employed in the +investigations noted in this volume. We notice a common deficiency in +the interpretation of the results. It appears to be sufficient to +isolate and identify a crystalline monose, without reference to the +yield or proportion to the parent substance, to establish some main +point in connection with its constitution. On the other hand, it is +clear that in hydrolysing a given cellulose-complex we ought to aim at +complete, i.e. _quantitative, statistics_. The hydrolytic transformation +of starch to dextrins and maltose has been followed in this way, and the +methods may serve as a model to which cellulose transformations should +be approximated. In fact, what is very much wanted is a systematic +re-examination of the typical celluloses in which all the constants of +the terms between the original and the ultimate monose groups shall be +determined. Such constants are similar to those for the starch-dextrose +series, viz. opticity and cupric reduction. Various methods of +fractionation are similarly available, chiefly the precipitation of the +intermediate 'dextrins' by alcohol. + +Where the original celluloses are homogeneous we should thus obtain +transformation series, similarly expressed to those of starch. In the +case of the celluloses which are mixtures, or of complex constitution, +there are various methods of either fractionating the original, or of +selectively attacking particular monoses resulting from the +transformation. By methods which are approximately quantitative a +mixture of groups, such as we have, for instance, in jute cellulose, +could be followed through the several stages of their resolution into +monoses. To put the matter generally, in these colloidal and complex +carbohydrates the ordinary physical criteria of molecular weight are +wanting. Therefore, we cannot determine the relationship of a given +product of decomposition to the parent molecule save by means of a +quantitative mass-proportion. Physical criteria are only of determining +value when associated with such constants as cupric reduction, and +these, again, must be referred to some arbitrary initial weight, such +as, for convenience, 100 parts of the original. + +Instead of adopting these methods, without which, as a typical case, the +mechanism of starch conversions could not have been followed, we have +been content with a purely qualitative study of the analogous series +obtainable from the celluloses under the action of sulphuric acid. A +very important field of investigation lies open, especially to those who +are generally familiar with the methods of studying starch conversions; +and we may hope in this direction for a series of valuable contributions +to the problem of the actual constitution of the celluloses. + +FOOTNOTES: + +[1] In this we are confirmed by other writers. See Tollens, _J. für +Landw._ 1901, p. 27. + + + + +SECTION I. GENERAL CHEMISTRY OF THE TYPICAL COTTON CELLULOSE + + +(p. 3)[2] ~Ash Constituents.~--It is frequently asserted that silica has a +structural function _sui generis_ in the plant skeleton, having a +relationship to the cellulosic constituents of the plant, distinct from +that of the inorganic ash components with which it is associated. It +should be noted that the matter has been specifically investigated in +two directions. In Berl. Ber. 5, 568 (A. Ladenburg), and again in 11, +822 (W. Lange), appear two papers 'On the Nature of Plant Constituents +containing Silicon,' which contain the results of experimental +investigations of equisetum species--distinguished for their +exceptionally high 'ash' with large proportion of silica--to determine +whether there are any grounds for assuming the existence of +silicon-organic compounds in the plant, the analogues of carbon +compounds. The conclusions arrived at are entirely negative. In +reference to the second assumption that the cuticular tissues of cereal +straws, of esparto, of the bamboo, owe their special properties to +siliceous components, it has been shown by direct experiment upon the +former that their rigidity and resistance to water are in no way +affected by cultivation in a silica-free medium. In other words, the +structural peculiarities of the gramineæ in these respects are due to +the physical characteristics chiefly of the (lignified) cells of the +hypodermal tissue, and to the composition and arrangement of the cells +of the cuticle. + +_'Swedish' filter papers_ of modern make are so far freed from inorganic +constituents that the weight of the ash may be neglected in nearly all +quantitative experiments [Fresenius, Ztschr. Anal Chem. 1883, 241]. It +represents usually about 1/1000 mgr. per 1 sq. cm. of area of the paper. + +_The form of an 'ash'_ derived from a fibrous structure, is that of the +'organic' original, more or less, according to its proportion and +composition. The proportion of 'natural ash' is seldom large enough, nor +are the components of such character as to give a coherent ash, but if +in the case of a fibrous structure it is combined or intimately mixed +with inorganic compounds deposited within the fibres from solution, the +latter may be made to yield a perfect skeleton of the fibre after +burning off the organic matter. It is by such means that the mantles +used in the Welsbach system of incandescent lighting are prepared. A +purified cotton fabric--or yarn--is treated with a concentrated solution +of the mixed nitrates of thorium and cerium, and, after drying, the +cellulose is burned away. A perfect and coherent skeleton of the fabric +is obtained, composed of the mixed oxides. Such mantles have fulfilled +the requirements of the industry up to the present time, but later +experiments forecast a notable improvement. It has been found that +artificial cellulose fibres can be spun with solutions containing +considerable proportions of soluble compounds of these oxides. Such +fibres, when knitted into mantles and ignited, yield an inorganic +skeleton of the oxides of homogeneous structure and smooth contour. De +Mare in 1894, and Knofler in 1895, patented methods of preparing such +cellulose threads containing the salts of thorium and cerium, by +spinning a collodion containing the latter in solution. When finally +ignited, after being brought into the suitable mantle form, there +results a structure which proves vastly more durable than the original +Welsbach mantle. The cause of the superiority is thus set forth by V. +H. Lewes in a recent publication (J. Soc. of Arts, 1900, p. 858): 'The +alteration in physical structure has a most extraordinary effect upon +the light-giving life of the mantle, and also on its strength, as after +burning for a few hundred hours the constant bombardment of the mantle +by dust particles drawn up by the rush of air in the chimney causes the +formation of silicates on the surface of the mantle owing to silica +being present in the air, and this seems to affect the Welsbach +structure far more than it does the "Clamond" type, with the result that +when burned continuously the Welsbach mantle falls to so low a pitch of +light emissivity after 500 to 600 hours, as to be a mere shadow of its +former self, giving not more than one-third of its original light, +whilst the Knofler mantle keeps up its light-emitting power to a much +greater extent, and the Lehner fabric is the most remarkable of all. Two +Lehner mantles which have now been burning continuously in my laboratory +for over 3,000 hours give at this moment a brighter light emissivity +than most of the Welsbachs do in their prime.' ...'The new developments +of the Clamond process form as important a step in the history of +incandescent gas lighting as the discoveries which gave rise to the +original mantles.' + +It has further been found that the oxides themselves can be dissolved in +the cellulose alkaline sulphocarbonate (viscose) solution, and +artificial threads have been spun containing from 25 to 30 p.ct. of the +oxides in homogeneous admixture with the cellulose. This method has +obvious advantages over the collodion method both in regard to the +molecular relationship of the oxides to the cellulose and to cheapness +of production. + + +UNTERSUCHUNGEN ÜBER VERSCHIEDENE BESTIMMUNGSMETHODEN DER CELLULOSE. + +H. SURINGAR AND B. TOLLENS (Ztschr. angew. Chem. 1896, No. 23). + +~INVESTIGATION OF METHODS OF DETERMINING CELLULOSE.~ + +_Introduction._--This is an exhaustive bibliography of the subject, +describing also the various methods of cellulose estimation, noted in +historical sequence. First, the Weende 'crude fibre' method (Henneberg) +with modifications of Wattenberg, Holdefleiss, and others is dealt with. +The product of this treatment, viz. 'crude fibre' is a mixture, +containing furfuroids and lignone compounds. Next follows a group of +processes which aim at producing a 'pure cellulose' by eliminating +lignone constituents, for which the merely hydrolytic treatments of the +Weende method are ineffectual. The method of F. Schulze--prolonged +digestion with dilute nitric acid, with addition of chlorate--has been +largely employed, though the composition of the product is more or less +divergent from a 'pure cellulose.' + +Dilute nitric acid at 60-80° (Cross and Bevan) and a dilute mixture of +nitric and sulphuric acids (Lifschutz) have been employed for isolating +cellulose from the lignocelluloses. Hoffmeister modifies the method of +Schulze by substituting hydrochloric acid for the nitric acid. Treatment +with the halogens associated with alkaline processes of hydrolysis is +the basis of the methods of Hugo Muller (bromine water) and Cross and +Bevan (chlorine gas). Lastly, the authors notice the methods based upon +the action of the alkaline hydrates at high temperatures (180°) in +presence of water (Lange), or of glycerin (Gabriel). The process of +heating to 210° with glycerin only (Hönig) yields a very impure and +ill-defined product. + +For comparative investigation of these processes certain celluloses and +cellulosic materials were prepared as follows: + +(a) _'Rag' cellulose._--A chemical filter paper, containing only +cotton and linen celluloses, was further purified by boiling with dilute +acid and dilute alkali. After thorough washing it was air-dried. + +(b) _Wood cellulose._--Pine wood sawdust was treated by digestion for +fourteen days with dilute nitric acid with addition of chlorate +(Schulze). The mass was washed and digested with alkaline lye (1.25 +p.ct. KOH), and exhaustively washed, treated with dilute acetic acid; +again washed, and finally air-dried. + +This product was found to yield 2.3 p.ct. furfural on distillation with +HCl (1.06 sp.gr.). + +(c) _Purified wood._--Pine wood sawdust was treated in succession with +dilute alkalis and acids, in the cold, and with alcohol and ether until +exhausted of products soluble in these liquids and reagents. + +In addition to the above the authors have also employed jute fibre and +raw cotton wool in their investigations. + +They note that the yield of cellulose is in many cases sensibly lowered +by treating the material after drying at the temperature of 100°. The +material for treatment is therefore weighed in the air-dry condition, +and a similar sample weighed off for drying at 100° for determination of +moisture. + +The main results of the experimental investigation are as follows:-- + +_Weende process_ further attacks the purified celluloses as follows: +Wood cellulose losing in weight 8-9 p.ct.; filter paper, 6-7.5 p.ct., +and the latter treated a second time loses a further 4-5 p.ct. It is +clear, therefore, that the process is of purely empirical value. + +_Schulze._--This process gave a yield of 47.6 p.ct. cellulose from pine +wood. The celluloses themselves, treated by the process, showed losses +of 1-3 p.ct. in weight, much less therefore than in the preceding case. + +_Hönig's_ method of heating with glycerin to 210° was found to yield +products very far removed from 'cellulose.' The process may have a +certain value in estimations of 'crude fibre,' but is dismissed from +further consideration in relation to cellulose. + +_Lange._--The purpose of the investigation was to test the validity of +the statement that the celluloses are not attacked by alkaline hydrates +at 180°. Experiments with pine wood yielded a series of percentages for +cellulose varying from 36 to 41; the 'purified wood' gave also variable +numbers, 44 to 49 per cent. It was found possible to limit these +variations by altering the conditions in the later stages of isolating +the product; but further experiments on the celluloses themselves +previously isolated by other processes showed that they were profoundly +and variably attacked by the 'Lange' treatment, wood cellulose losing 50 +per cent. of its weight, and filter paper (cellulose) losing 15 per +cent. Further, a specimen of jute yielded 58 per cent. of cellulose by +this method instead of the normal 78 per cent. It was also found that +the celluloses isolated by the process, when subjected to a second +treatment, underwent a further large conversion into soluble +derivatives, and in a third treatment further losses of 5-10 per cent +were obtained. The authors attach value, notwithstanding, to the process +which they state to yield an 'approximately pure cellulose,' and they +describe a modified method embodying the improvements in detail +resulting from their investigation. + +_Gabriel's_ method of heating with a glycerin solution of alkaline +hydrate is a combination of 'Hönig' and 'Lange.' An extended +investigation showed as in the case of the latter that the +celluloses themselves are more or less profoundly attacked by the +treatment--further that the celluloses isolated from lignocelluloses and +other complex raw materials are much 'less pure' than those obtained by +the Lange process. Thus, notably in regard to furfural yielding +constituents, the latter yield 1-2 p.ct. furfural, whereas _specimens of +'jute cellulose'_ obtained by the Gabriel process were found to yield _9 +to 13 p.ct. furfural_. + +_Cross and Bevan._--Chlorination process yielded in the hands of the +authors results confirming the figures given in 'Cellulose' for yield of +cellulose. Investigation of the products for yield of furfural, gave 9 +p.ct. of this aldehyde showing the presence of celluloses, other than +the normal type. + +_Conclusions._--The subjoined table gives the mean numerical results for +yield of end-product or 'cellulose' by the various methods. In the case +of the 'celluloses' the results are those of the further action of the +several processes on the end-product of a previous process. + + | Methods + | F. Schulze | Weende | Lange | Gabriel | Cross + | | | | | and Bevan +-------------------------------------------------------------------------- +Wood cellulose | 98.51 | 91.52 | 48.22 | 55.93 | -- +Filter paper cellulose | 99.62 | 95.63 | 78.17 | 79.77 | -- +Swedish filter paper | 96.58 | -- | 84.76 | -- | -- +Ordinary filter paper | 98.17 | 93.39 | 86.58 | -- | -- +Cotton ('wool') | 98.38 | 89.98 | 63.96 | 67.88 | -- +Jute | -- | -- | 57.93 | 71.64 | 75.27 +Purified wood | -- | -- |{49.27 | -- | -- + | | |{46.56 | | +Raw wood | 47.60 | -- |{40.82 | -- | -- + | | |{38.87 | | +-------------------------------------------------------------------------- + +The final conclusion drawn from the results is that none of the +processes fulfil the requirements of an ideal method. Those which may +be carried out in a reasonably short time are deficient in two +directions: (1) they yield a 'cellulose' containing more or less +oxycellulose; (2) the celluloses themselves are attacked under the +conditions of treatment, and the end product or cellulose merely +represents a particular and at the same time variable equilibrium, as +between the resistance of the cellulose and the attack of the reagents +employed; this attack being by no means confined to the non-cellulose +constituents. Schulze's method appears to give the nearest approximation +to the 'actual cellulose' of the raw material. + + * * * * * + +(p. 8) ~SOLUTIONS OF CELLULOSE~--(1) ~ZINC CHLORIDE.~--To prepare a +homogeneous solution of cellulose by means of the neutral chloride, a +prolonged digestion at or about 100° with the concentrated reagent is +required. The dissolution of the cellulose is not a simple phenomenon, +but is attended with hydrolysis and a certain degree of condensation. +The latter result is evidenced by the formation of furfural, the former +by the presence of soluble carbohydrates in the solution obtained by +diluting the original solution and filtering from the reprecipitated +cellulose. The authors have observed that in carefully conducted +experiments cotton cellulose may be dissolved in the reagent, and +reprecipitated with a loss of only 1 p.ct. in weight. This, however, is +a 'net' result, and leaves undetermined the degree of hydration of the +recovered cellulose as of hydrolysis of the original to groups of lower +molecular weights. Bronnert finds that a previous hydration of the +cellulose--e.g. by the process of alkaline mercerisation and removal of +the alkali by washing--enables the zinc chloride to effect its +dissolution by digestion in the cold. (U.S. patent, 646,799/1900. See +also p. 59.) + +_Industrial applications._--(a) _Vulcanised fibre_ is prepared by +treating paper with four times its weight of the concentrated aqueous +solution (65-75° B.), and in the resulting gelatinised condition is +worked up into masses, blocks, sheets, &c., of any required thickness. +The washing of these masses to remove the zinc salt is a very lengthy +operation. + +To render the product waterproof the process of nitration is sometimes +superadded [D.R.P. 3181/1878]. Further details of manufacture are given +in Prakt. Handbuch d. Papierfabrikation, p. 1703 [C. Hofmann]. + +(b) _Calico-printing._--The use of the solution as a thickener or +colour vehicle, more especially as a substitute for albumen in pigment +styles, was patented by E. B. Manby, but the process has not been +industrially developed [E.P. 10,466/1894]. + +(c) _Artificial silk._--This is a refinement of the earlier +applications of the solution in spinning cellulose threads for +conversion into carbon filaments for electrical glow-lamps. This section +will be found dealt with on p. 59. + +(p. 13) (2) ~Cuprammonium solution.~--The application of the solution of +cellulose in cuprammonium to the production of a fine filament in +continuous length, 'artificial silk,' has been very considerably studied +and developed in the period 1897-1900, as evidenced by the series of +patents of Fremery and Urban, Pauly, Bronnert, and others. The subject +will also be found dealt with on p. 58. + + * * * * * + +(p. 15) ~Reactions of cellulose with iodine.~--In a recent paper, F. +Mylius deals with the reaction of starch and cellulose with iodine, +pointing out that the blue colouration depends upon the presence of +water and iodides. In absence of the latter, and therefore in presence +of compounds which destroy or absorb hydriodic acid--e.g. iodic +acid--there results a _brown_ addition product. The products in question +have the characteristics of _solid solutions_ of the halogen. (Berl. +Ber. 1895, 390.) + +(24) ~Mercerisation~--Notwithstanding the enormous recent developments in +the industrial application of the mercerising reaction, there have been +no noteworthy contributions to the theoretical aspects of the subject. +The following abstract gives an outline of the scope of an important +technical work on the subject. + + +DIE MERCERISATION DER BAUMWOLLE. + +PAUL GARDNER (Berlin: 1898. J. Springer). + +~THE MERCERISATION OF COTTON.~ + +This monograph of some 150 pages is chiefly devoted to the patent +literature of the subject. The chemical and physical modifications of +the cotton substance under the action of strong alkaline lye, were set +forth by Mercer in 1844-5, and there has resulted from subsequent +investigations but little increase in our knowledge of the fundamental +facts. The treatment was industrially developed by Mercer in certain +directions, chiefly (1) for preparing webs of cloth required to stand +considerable strain, and (2) for producing crêpon effects by local or +topical action of the alkali. But the results achieved awakened but a +transitory interest, and the matter passed into oblivion; so much so, +indeed, that a German patent [No. 30,966] was granted in 1884 to the +Messrs. Depouilly for crêpon effects due to the differential shrinkage +of fabrics under mercerisation, by processes and treatments long +previously described by Mercer. Such effects have had a considerable +vogue in recent years, but it was not until the discovery of the +lustreing effect resulting from the association of the mercerising +actions with the condition of strain or tension of the yarn or fabric +that the industry in 'mercerised' goods was started on the lines which +have led to the present colossal development. The merit of this +discovery is now generally recognised as belonging to Thomas and Prevost +of Crefeld, notwithstanding that priority of patent right belongs to the +English technologist, H. A. Lowe. + +The author critically discusses the grounds of the now celebrated patent +controversy, arising out of the conflict of the claims of German patent +85,564/1895 of the former, and English patent 4452/1890 of the latter. +The author concludes that Lowe's specification undoubtedly describes the +lustreing effect of mercerising in much more definite terms than that of +Thomas and Prevost. These inventors, on the other hand, realised the +effect industrially, which Lowe certainly failed to do, as evidenced by +his allowing the patent to lapse. As an explanation of his failure, the +author suggests that Lowe did not sufficiently extend his observations +to goods made from Egyptian and other long-stapled cottons, in which +class only are the full effects of the added lustre obtained. + +Following these original patents are the specifications of a number of +inventions which, however, are of insignificant moment so far as +introducing any essential variation of the mercerising treatment. + +The third section of the work describes in detail the various mechanical +devices which have been patented for carrying out the treatment on yarn +and cloth. + +The fourth section deals with the fundamental facts underlying the +process and effects summed up in the term 'mercerisation.' These are as +follows:-- + +(a) Although all forms of fibrous celluloses are similarly affected by +strong alkaline solutions, it is only the Egyptian and other +long-stapled cottons--i.e. the goods made from them--which under the +treatment acquire the special high lustre which ranks as 'silky.' Goods +made from American cottons acquire a certain 'finish' and lustre, but +the effects are not such as to have an industrial value--i.e. a value +proportional to the cost of treatment. + +(b) The lustre is determined by exposing the goods to strong tension, +either when under the action of the alkali, or subsequently, but only +when the cellulose is in the special condition of hydration which is the +main chemical effect of the mercerising treatment. + +(c) The degree of tension required is approximately that which opposes +the shrinkage in dimensions, otherwise determined by the action of the +alkali. The following table exhibits the variations of shrinkage of +Egyptian when mercerised without tension, under varying conditions as +regards the essential factors of the treatment--viz. (1) concentration +of the alkaline lye, (2) temperature, and (3) duration of action (the +latter being of subordinate moment):-- + + _______________________________________________________________________ +| | | | | | +| Concentration | | | | | +| of lye (NaOH) | 5°B. | 10°B. | 15°B | 25°B | +| | | | | | | | | | | | +| Duration of | | | | | | | | | | | +| action in | 1 | 10 | 30 | 1 | 10 | 30 | 1 | 10 | 30 | | +| minutes | | | | | | | | | | | +| | | | | | | | | | | | +| Temperatures | Percentage shrinkages (Egyptian yarns) as under:-- | +| as under:-- | | | | | | | | | | | +| 2° | 0 | 0 | 0 | 1 | 1 | 1 | 12.2 | 15.2 | 15.8 | 19.2 | +| 18° | 0 | 0 | 0 | 0 | 0 | 0 | 8.0 | 8.8 | 11.8 | 19.8 | +| 30° | 0 | 0 | 0 | 0 | 0 | 0 | 4.6 | 4.6 | 6.0 | 19.0 | +| 80° | 0 | 0 | 0 | 0 | 0 | 0 | 3.5 | 3.5 | 9.8 | 13.4 | +|_______________|___|____|____|___|____|____|______|______|______|______| + _______________________________________________________________________ +| | | | | +| Concentration | | | | +| of lye (NaOH) | 25°B | 30°B | 35°B | +| | | | | | | | | | +| Duration of | | | | | | | | | +| action in | 10 | 30 | 1 | 10 | 30 | 1 | 10 | 30 | +| minutes | | | | | | | | | +| | | | | | | | | | +| Temperatures | Percentage shrinkages (Egyptian yarns) as under:-- | +| as under:-- | | | | | | | | | +| 2° | 19.8 | 21.5 | 22.7 | 22.7 | 22.7 | 24.2 | 24.5 | 24.7 | +| 18° | 20.1 | 21.0 | 21.2 | 22.0 | 22.3 | 23.5 | 23.8 | 24.7 | +| 30° | 19.5 | 19.0 | 18.5 | 19.5 | 19.8 | 20.7 | 21.0 | 21.1 | +| 80° | 13.7 | 14.2 | 15.0 | 15.1 | 15.5 | 15.0 | 15.2 | 15.4 | +|_______________|______|______|______|______|______|______|______|______| + +The more important general indications of the above results are--(1) The +mercerisation action commences with a lye of 10°B., and increases with +increased strength of the lye up to a maximum at 35°B. There is, +however, a relatively slight increase of action with the increase of +caustic soda from 30-40°B. (2) For optimum action the temperature should +not exceed 15-20°C. (3) The duration of action is of proportionately +less influence as the concentration of the lye increases. As the maximum +effect is attained the action becomes practically instantaneous, the +only condition affecting it being that of penetration--i.e. actual +contact of cellulose and alkali. + +(d) The question as to whether the process of 'mercerisation' involves +chemical as well as physical effects is briefly discussed. The author is +of opinion that, as the degree of lustre obtained varies with the +different varieties of cotton, the differentiation is occasioned by +differences in chemical constitution of these various cottons. The +influence of the chemical factors is also emphasised by the increased +dyeing capacity of the mercerised goods, which effect, moreover, is +independent of those conditions of strain or tension under mercerisation +which determine lustre. It is found in effect that with a varied range +of dye stuffs a given shade is produced with from 10 to 30 p.ct. less +colouring matter than is required for the ordinary, i.e. unmercerised, +goods. + +In reference to the constants of strength and elasticity, Buntrock gives +the following results of observations upon a 40^{5} twofold yarn, five +threads of 50 cm. length being taken for each test(Prometheus, 1897, p. +690): (a) the original yarn broke under a load of 1440 grms.; (b) +after mercerisation without tension the load required was 2420 grms.; +(c) after mercerisation under strain, 1950 grms. Mercerisation, +therefore, increases the strength of the yarn from 30 to 66 p.ct., the +increase being lessened proportionately to the strain accompanying +mercerisation. _Elasticity_, as measured by the extension under the +breaking load, remains about the same in yarns mercerised under strain, +but when allowed to shrink under mercerisation there is an increase of +30-40 p.ct. over the original. + +The _change of form_ sustained by the individual fibres has been studied +by H. Lange [Farberzeitung, 1898, 197-198], whose microphotographs of +the cotton fibres, both in length and cross-section, are reproduced. In +general terms, the change is from the flattened riband of the original +fibre to a cylindrical tube with much diminished and rounded central +canal. The effect of strain under mercerisation is chiefly seen in the +contour of the surface, which is smooth, and the obliteration at +intervals of the canal. Hence the increased transparency and more +complete reflection of the light from the surface, and the consequent +approximation to the optical properties of the silk fibre. + +The work concludes with a section devoted to a description of the +various practical systems of mercerisation of yarns in general practice +in Germany, and an account of the methods adopted in dyeing the +mercerised yarns. + + +RESEARCHES ON MERCERISED COTTON. + +A. FRAENKEL and P. FRIEDLAENDER (Mitt. k.-k. Techn. Gew. Mus., Wien, +1898, 326). + +The authors, after investigation, are inclined to attribute the lustre +of mercerised cotton to the absence of the cuticle, which is destroyed +and removed in the process, partly by the chemical action of the alkali, +and partly by the stretching at one or other stage of the process. The +authors have investigated the action of alcoholic solutions of soda +also. The lustre effects are not obtained unless the action of water is +associated. + +In conclusion, the authors give the following particulars of breaking +strains and elasticity:-- + +-------------------------------------------------------------------------- +Treatment | Experiments | Breaking strain | Elasticity +-------------------------------------------------------------------------- + | | | Elongation + | | Grammes | in mm. + | | | +Cotton unmercerised. | 1 | 360 | 20 + | 2 | 356 | 20 + | 3 | 360 | 22 + | | | +Mercerised with | | | + Soda 35°B. | 1 | 530 | 44 + | 2 | 570 | 40 + | 3 | 559 | 35 + | | | + Alcoholic soda 10 p.ct. | 1 | 645 | 24 + cold | 2 | 600 | 27 + | 3 | 610 | 33 + | | | + Alcoholic soda 10 p.ct. | 5 | 740 | 33 + hot | 2 | 730 | 38 + | 3 | 690 | 30 +-------------------------------------------------------------------------- + +FOOTNOTES: + +[2] This and other similar references are to the matter of the original +volume (1895). + + + + +SECTION II. SYNTHETICAL DERIVATIVES--SULPHOCARBONATES AND ESTERS + + +(p. 25) ~Cellulose sulphocarbonate.~--Further investigations of the +reaction of formation as well as the various reactions of decomposition +of the compound, have not contributed any essential modification or +development of the subject as originally described in the author's first +communications. A large amount of experimental matter has been +accumulated in view of the ultimate contribution of the results to the +general theory of colloidal solutions. But viscose is a complex product +and essentially variable, through its pronounced tendency to progressive +decomposition with reversion of the cellulose to its insoluble and +uncombined condition. The solution for this reason does not lend itself +to exact measurement of its physical constants such as might elucidate +in some measure the progressive molecular aggregation of the cellulose +in assuming spontaneously the solid (hydrate) form. Reserving the +discussion of these points, therefore, we confine ourselves to recording +results which further elucidate special points. + +_Normal and other celluloses._--We may certainly use the sulphocarbonate +reaction as a means of defining a normal cellulose. As already pointed +out, cotton cellulose passes quantitatively through the cycle of +treatments involved in solution as sulphocarbonate and decomposition of +the solution with regeneration as structureless or amorphous cellulose +(hydrate). + +Analysis of this cellulose shows a fall of carbon percentage from 44.4 +to 43.3, corresponding with a change in composition from +C_{6}H_{10}O_{5} to 4C_{6}H_{10}O_{5}.H_{2}O. The partial hydrolysis +affects the whole molecule, and is limited to this effect, whereas, in +the case of celluloses of other types, there is a fractionation of the +mass, a portion undergoing a further hydrolysis to compounds of lower +molecular weight and permanently soluble. Thus in the case of the wood +celluloses the percentage recovered from solution as viscose is from 93 +to 95 p.ct. It is evident that these celluloses are not homogeneous. A +similar conclusion results from the presence of furfural-yielding +compounds with the observation that the hydrolysis to soluble +derivatives mainly affects these derivatives. In the empirical +characterisation of a normal cellulose, therefore, we may include the +property of quantitative regeneration or recovery from its solution as +sulphocarbonate. + +In the use of the word 'normal' as applied to a 'bleached' cotton, we +have further to show in what respects the sulphocarbonate reaction +differentiates the bleached or purified cotton cellulose from the raw +product. The following experiments may be cited: Specimens of American +and Egyptian cottons in the raw state, freed from mechanical, i.e. +non-fibrous, impurities, were treated with a mercerising alkali, and the +alkali-cotton subsequently exposed to carbon disulphide. The product of +reaction was further treated as in the preparation of the ordinary +solution; but in place of the usual solution, structureless and +homogeneous, it was observed to retain a fibrous character, and the +fibres, though enormously swollen, were not broken down by continued +vigorous stirring. After large dilution the solutions were filtered, and +the fibres then formed a gelatinous mass on the filters. After +purification, the residue was dried and weighed. The American cotton +yielded 90.0 p.ct., and the Egyptian 92.0 p.ct. of its substance in the +form of this peculiar modification. The experiment was repeated, +allowing an interval of 24 hours to elapse between the conversion into +alkali-cotton and exposure of this to the carbon disulphide. The +quantitative results were identical. + +There are many observations incidental to chemical treatments of cotton +fabrics which tend to show that the bleaching process produces other +effects than the mere removal of mechanical impurities. In the +sulphocarbonate reaction the raw cotton, in fact, behaves exactly as a +compound cellulose. Whether the constitutional difference between raw +and bleached cotton, thus emphasised, is due to the group of components +of the raw cotton, which are removed in the bleaching process, or to +internal constitutional changes determined by the bleaching treatments, +is a question which future investigation must decide. + +_The normal sulphocarbonate (viscose)._--In the industrial applications +of viscose it is important to maintain a certain standard of composition +as of the essential physical properties of the solution, notably +viscosity. It may be noted first that, with the above-mentioned +exception, the various fibrous celluloses show but slight differences in +regard to all the essential features of the reactions involved. In the +mercerising reaction, or alkali-cellulose stage, it is true the +differences are considerable. With celluloses of the wood and straw +classes there is a considerable conversion into soluble +alkali-celluloses. If treated with water these are dissolved, and on +weighing back the cellulose, after thorough washing, treatment with +acid, and finally washing and drying, it will be found to have lost from +15 to 20 p.ct. in weight. The lower grade of celluloses thus dissolved +are only in part precipitated in acidifying the alkaline solution. On +the other hand, after conversion into viscose, the cellulose when +regenerated re-aggregates a large proportion of these lower grade +celluloses, and the final loss is as stated above, from 5 to 7 p.ct. +only. + +Secondly, it is found that all the conditions obtaining in the +alkali-cellulose stage affect the subsequent viscose reaction and the +properties of the final solution. The most important are obviously the +proportion of alkali to cellulose and the length of time they are in +contact before being treated with carbon disulphide. An excess of +alkali beyond the 'normal' proportion--viz. 2NaOH per 1 mol. +C_{6}H_{10}O_{5}--has little influence upon the viscose reaction, but +lowers the viscosity of the solution of the sulphocarbonate prepared +from it. But this effect equally follows from addition of alkali to the +viscose itself. The alkali-cellulose changes with age; there is a +gradual alteration of the molecular structure of the cellulose, of which +the properties of the viscose when prepared are the best indication. +There is a progressive loss of viscosity of the solution, and a +corresponding deterioration in the structural properties of the +cellulose when regenerated from it--especially marked in the film form. +In regard to viscosity the following observations are typical:-- + + (a) A viscose of 1.8 p.ct. cellulose prepared from an + alkali-cellulose (cotton) fourteen days old. + + (b) Viscose of 1.8 p.ct. cellulose from an alkali-cellulose + (cotton) three days old. + + (c) Glycerin diluted with 1/3 vol. water. + + a b b c + Diluted with + equal vol. + water +Times of flow of equal volumes from 112 321 103 170 + narrow orifice in seconds + +Similarly the cellulose in reverting to the solid form from these +'degraded' solutions presents a proportionate loss of cohesion and +aggregating power expressed by the inferior strength and elasticity of +the products. Hence, in the practical applications of the product where +the latter properties are of first importance, it is necessary to adopt +normal standards, such as above indicated, and to carefully regulate all +the conditions of treatment in each of the two main stages of reaction, +so that a product of any desired character may be invariably obtained. + +Incidentally to these investigations a number of observations have been +made on the alkali-cellulose (cotton) after prolonged storage in closed +vessels. It is well known that starch undergoes hydrolysis in contact +with aqueous alkalis of a similar character to that determined by acids +[Béchamp, Annalen, 100, 365]. The recent researches of Lobry de Bruyn +[Rec. Trav. Chim. 14, 156] upon the action of alkaline hydrates in +aqueous solution on the hexoses have established the important fact of +the resulting mobility of the CO group, and the interchangeable +relationships of typical aldoses and ketoses. It was, therefore, not +improbable that profound hydrolytic changes should occur in the +cellulose molecule when kept for prolonged periods as alkali-cellulose. + +We may cite an extreme case. A series of products were examined after +12-18 months' storage. They were found to contain only 3-5 p.ct. +'soluble carbohydrates'; these were precipitated by Fehling's solution +but without reduction on boiling. They were, therefore, of the cellulose +type. On acidifying with sulphuric acid and distilling, traces only of +volatile acid were produced. It is clear, therefore, that the change of +molecular weight of the cellulose, the disaggregation of the undoubtedly +large molecule of the original 'normal' cellulose--which effects are +immediately recognised in the viscose reactions of such products--are of +such otherwise limited character that they do not affect the +constitution of the unit groups. We should also conclude that the +cellulose type of constitution covers a very wide range of minor +variations of molecular weight or aggregation. + +The resistance of the normal cellulose to the action of alkalis under +these hydrolysing conditions should be mentioned in conjunction with the +observations of Lange, and the results of the later investigations of +Tollens, on its resistance to 'fusion' with alkaline hydrates at high +temperatures (180°). The degree of resistance has been established only +on the empirical basis of weighing the product recovered from such +treatment. The product must be investigated by conversion into typical +cellulose derivatives before we can pronounce upon the constitutional +changes which certainly occur in the process. But for the purpose of +this discussion it is sufficient to emphasise the extraordinary +resistance of the normal cellulose to the action of alkalis, and to +another of the more significant points of differentiation from starch. + +_Chemical constants of cellulose sulphocarbonate (solution)._--In +investigations of the solutions we make use of various analytical +methods, which may be briefly described, noting any results bearing upon +special points. + +_Total alkali._--This constant is determined by titration in the usual +way. The cellulose ratio, C_{6}H_{10}O_{5} : 2NaOH, is within the +ordinary error of observation, 2 : 1 by weight. A determination of alkali +therefore determines the percentage of cellulose. + +_Cellulose_ may be regenerated in various ways--viz. by the action of +heat, of acids, of various oxidising compounds. It is purified for +weighing by boiling in neutral sulphite of soda (2 p.ct. solution) to +remove sulphur, and in very dilute acids (0.33 p.ct. HCl) to decompose +residues of 'organic' sulphur compounds. It may also be treated with +dilute oxidants. After weighing it may be ignited to determine residual +inorganic compounds. + +_Sulphur._--It has been proved by Lindemann and Motten [Bull. Acad. R. +Belg. (3), 23, 827] that the sulphur of sulphocarbonates (as well as of +sulphocyanides) is fully oxidised (to SO_{3}) by the hypochlorites +(solutions at ordinary temperatures). The method may be adapted as +required for any form of the products or by-products of the viscose +reaction to be analysed for _total sulphur_. + +The sulphur present in the form of dithiocarbonates, including the +typical cellulose xanthogenic acid, is approximately isolated and +determined as CS_{2} by adding a zinc salt in excess, and distilling off +the carbon disulphide from a water bath. From freshly prepared solutions +a large proportion of the disulphide originally interacting with the +alkali and cellulose is recovered, the result establishing the general +conformity of the reaction to that typical of the alcohols. On keeping +the solutions there is a progressive interaction of the bisulphide and +alkali, with formation of trithiocarbonates and various sulphides. In +decomposing these products by acid reagents hydrogen sulphide and free +sulphur are formed, the estimation of which presents no special +difficulties. + +In the spontaneous decomposition of the solution a large proportion of +the sulphur resumes the form of the volatile disulphide. This is +approximately measured by the loss in total sulphur in the following +series of determinations, in which a viscose of 8.5 p.ct. strength +(cellulose) was dried down as a thin film upon glass plates, and +afterwards analysed: + +(a) Proportion of sulphur to cellulose (100 pts.) in original. +(b) After spontaneous drying at ordinary temperature. +(c) After drying at 40°C. +(d) As in (c), followed, by 2 hours' heating at 98°. +(e) As in (c), followed by 5 hours' heating at 98°. + + a b c d e + Total sulphur 40.0 25.0 31.0 23.7 10.4 + +The dried product in (b) and (c) was entirely resoluble in water; in +(d) and (e), on the other hand, the cellulose was fully regenerated, +and obtained as a transparent film. + +_Iodine reaction._--Fresh solutions of the sulphocarbonate show a fairly +constant reaction with normal iodine solution. At the first point, where +the excess of iodine visibly persists, there is complete precipitation +of the cellulose as the bixanthic sulphide; and this occurs when the +proportion of iodine added reaches 3I_{2} : 4Na_{2}O, calculated to the +total alkali. + +_Other decompositions._--The most interesting is the interaction which +occurs between the cellulose xanthogenate and salts of ammonia, which is +taken advantage of by C. H. Stearn in his patent process of spinning +artificial threads from viscose. The insoluble product which is formed +in excess of the solution of ammonia salt is free from soda, and +contains 9-10 p.ct. total sulphur. The product retains its solubility in +water for a short period. The solution may be regarded as containing the +ammonium cellulose xanthate. This rapidly decomposes with liberation of +ammonia and carbon disulphide, and separation of cellulose (hydrate). As +precipitated by ammonium-chloride solution the gelatinous thread +contains 15 p.ct. of cellulose, with a sp.gr. 1.1. The process of +'fixing'--i.e. decomposing the xanthic residue--consists in a short +exposure to the boiling saline solution. The further dehydration, with +increase of gravity and cellulose content, is not considerable. The +thread in its final air-dry state has a sp.gr. 1.48. + + * * * * * + +~Cellulose Benzoates.~--These derivatives have been further studied by the +authors. The conditions for the formation of the monobenzoate +[C_{6}H_{9}O_{4}.O.CO.Ph] are very similar to those required for the +sulphocarbonate reaction. The fibrous cellulose (cotton), treated with a +10 p.ct. solution NaOH, and subsequently with benzoyl chloride, gives +about 50 p.ct. of the theoretical yield of monobenzoate. Converted by 20 +p.ct. solution NaOH into alkali-cellulose, and with molecular +proportions as below, the following yields were obtained:-- + + Calc. for + Monobenzoate +(a) C_{6}H_{10}O_{5} : 2.0-2.5 NaOH : C_{6}H_{5}.COCl-- 150.8} + }164.0 +(b) C_{6}H_{10}O_{5} : 2.0-2.5 NaOH : 1.5 mol. C_{6}H_{5}COCl 159.0} + +An examination of (a) showed that some dibenzoate (about 7 p.ct.) had +been formed. The product () was exhaustively treated with cuprammonium +solution, to which it yielded about 20 p.ct. of its weight, which was +therefore unattacked cellulose. + +Under conditions as above, but with 2.5 mol. C_{6}H_{5}COCl, a careful +comparison was made of the behaviour of the three varieties of cotton, +which were taken in the unspun condition and previously fully bleached +and purified. + + ___________________________________________________________________ +| | | | | +| | Sea Island | Egyptian | American | +|________________________________|____________|__________|__________| +| | | | | +| Aggregate yield of benzoate | 153 | 148 | 152 | +| Moisture in air dry state | 5.28 | 5.35 | 5.15 | +| Proportion of dibenzoate p.ct. | 8.30 | 13.70 | 9.4 | +| Yield of cellulose by | 58.0 | 54.0 | 58.3 | +| saponification | | | | +|________________________________|____________|__________|__________| + +It appears from these results that the benzoate reaction may proceed to +a higher limit (dibenzoate) in the case of Egyptian cotton. This would +necessarily imply a higher limit of 'mercerisation,' under equal +conditions of treatment with the alkaline hydrate. It must be noted that +in the conversion of the fibrous cellulose into these (still) fibrous +monobenzoates, there are certain mechanical conditions imported by the +structural features of the ultimate fibres. For the elimination of the +influence of this factor a large number of quantitative comparisons will +be necessary. The above results are therefore only cited as typical of a +method of comparative investigation, more especially of the still open +questions of the cause of the superior effects in mercerisation of +certain cottons (see p. 23). It is quite probable that chemical as well +as structural factors co-operate in further differentiating the cottons. + +Further investigation of the influence upon the benzoate reaction, of +increase of concentration of the soda lye, used in the preliminary +alkali cellulose reaction, from 20 to 33 p.ct. NaOH, established (1) +that there is no corresponding increase in the benzoylation, and (2) +that this ester reaction and the sulphocarbonate reaction are closely +parallel, in that the degree and limit of reaction are predetermined by +the conditions of formation of the alkali cellulose. + +_Monobenzoate_ prepared as above described is resistant to all solvents +of cellulose and of the cellulose esters, and is therefore freed from +cellulose by treatment with the former, and from the higher benzoate by +treatment with the latter. Several of these, notably pyridine, phenol +and nitrobenzene, cause considerable swelling and gelatinisation of the +fibres, but without solution. + +_Structureless celluloses_ of the 'normal' type, and insoluble therefore +in alkaline lye, treated under similar conditions to those described +above for the fibrous celluloses, yield a higher proportion of +dibenzoate. The following determinations were made with the cellulose +(hydrate) regenerated from the sulphocarbonate:-- + +Mol. proportions of reagents Yield Dibenzoate p.ct. +C_{6}H_{10}O_{5} : 2NaOH : 2BzCl 145 34.7 + [Caustic soda at 10 per cent. NaOH] + +C_{6}H_{10}O_{5} : 4NaOH : 2BzCl 162 62.7 + [Caustic soda at 20 per cent. NaOH] + +_Limit of reaction._--The cellulose in this form having shown itself +more reactive, it was taken as the basis for determining the maximum +proportion of OH groups yielding to this later reaction. The systematic +investigations of Skraup [Monatsh. 10, 389] have determined that as +regards the interacting groups the molecular proportions 1 OH : 7 NaOH : +5 BzCl, ensure complete or maximum esterification. The maximum of OH +groups in cellulose being 4, the reagents were taken in the proportion +C_{6}H_{10}O_{5} : 4 [7 NaOH : 5 BzCl]. The yield of crude product, after +purifying as far as possible from the excess of benzoic acid, was 240 +p.ct. [calculated for dibenzoate 227 p.ct.]. On further investigating +the crude product by treatment with solvents, it was found to have still +retained benzoic acid. There was also present a proportion of only +partially attacked cellulose (monobenzoate). The soluble benzoate +amounted to 90 p.ct. of the product. It may be generally concluded that +the dibenzoate represents the normal maximum but that with the hydrated +and partly hydrolysed cellulose molecule, as obtained by regeneration +from the sulphocarbonate, other OH groups may react, but they are only a +fractional proportion in relation to the unit group C_{6}H_{10}O_{5}. In +this respect again there is a close parallelism between the +sulphocarbonate and benzoyl-ester reactions. + +_The dibenzoate_, even when prepared from the fibrous celluloses, is +devoid of structure, and its presence in admixture with the fibrous +monobenzoate is at once recognised as it constitutes a structureless +incrustation. Under the microscope its presence in however minute +proportion is readily observed. As stated it is soluble in certain of +the ordinary solvents of the cellulose esters, e.g. chloroform, acetic +acid, nitrobenzene, pyridine, and phenol. It is not soluble in ether or +alcohol. + +_Hygroscopic moisture of benzoates._--The crude monobenzoate retains +5.0-5.5 p.ct. moisture in the air-dry condition. After removal of the +residual cellulose this is reduced to 3.3 p.ct. under ordinary +atmospheric conditions. The purified dibenzoates retain 1.6 p.ct. under +similar conditions. + +_Analysis of benzoates._--On saponification of these esters with +alcoholic sodium hydrate, anomalous results are obtained. The acid +numbers, determined by titration in the usual way, are 10-20 p.ct. in +excess of the theoretical, the difference increasing with the time of +boiling. Similarly the residual cellulose shows a deficiency of 5-9 +p.ct. + +It is by no means improbable that in the original ester reaction there +is a constitutional change in the cellulose molecule causing it to break +down in part under the hydrolysing treatment with formation of acid +products. This point is under investigation. Normal results as regards +acid numbers, on the other hand, are obtained by saponification with +sodium ethylate in the cold, the product being digested with the +half-saturated solution for 12 hours in a closed flask. + +The following results with specimens of mono- and dibenzoate, purified, +as far as possible, may be cited: + + Combustion results Saponification results + Calc. C_{6}H_{5}.COOH Calc. Cellulose Calc. +Monobenzoate C 56.60 58.65} + H 5.06 5.26} 46.0 45.9 58.0 60.8 + +Dibenzoate C 63.10 64.86} + H 3.40 4.86} 65.5 66.6 34.3 40.3 + +The divergence of the numbers, especially for the dibenzoate, in the +case of the hydrogen, and yield of cellulose on hydrolysis are +noteworthy. They confirm the probability of the occurrence of secondary +changes in the ester reactions. + +_Action of nitrating acid upon the benzoates._--From the benzoates above +described, mixed nitro-nitric esters are obtained by the action of the +mixture of nitric and sulphuric acids. The residual OH groups of the +cellulose are esterified and substitution by an NO_{2} group takes place +in the aromatic residue, giving a mixed nitric nitrobenzoic ester. The +analysis of the products points to the entrance of 1 NO_{2} group in the +benzoyl residue in either case; in the cellulose residue 1 OH readily +reacts. Higher degrees of nitration are attained by the process of +solution in concentrated nitric acid and precipitation by pouring into +sulphuric acid. In describing these mixed esters we shall find it +necessary to adopt the C_{12} unit formula. + +In analysing these products we have employed the Dumas method for _total +nitrogen_. For the O.NO_{2} groups we have found the nitrometer and the +Schloesing methods to give concordant results. For the NO_{2} groups it +was thought that Limpricht's method, based upon reduction with stannous +chloride in acid solution (HCl), would be available. The quantitative +results, however, were only approximate, owing to the difficulty of +confining the reduction to the NO_{2} groups of the nitrobenzoyl +residue. By reduction with ammonium sulphide the O.NO_{2} groups were +entirely removed as in the case of the cellulose nitrates; the NO_{2} +was reduced to NH_{2} and there resulted a cellulose amidobenzoate, +which was diazotised and combined with amines and phenols to form yellow +and red colouring matters, the reacting residue remaining more or less +firmly combined with the cellulose. + +_Cellulose dinitrate-dinitrobenzoate, and cellulose +trinitrate-dinitrobenzoate._--On treating the fibrous benzoate--which is +a dibenzoate on the C_{12} basis--with the acid mixture under the usual +conditions, a yellowish product is obtained, with a yield of 140-142 +p.ct. The nitrobenzoate is insoluble in ether alcohol, but is soluble in +acetone, acetic acid, and nitrobenzene. In purifying the product the +former solvent is used to remove any cellulose nitrates. To obtain the +maximum combination with nitroxy-groups, the product was dissolved in +concentrated nitric acid, and the solution poured into sulphuric acid. + +The following analytical results were obtained (a) for the product +obtained directly from the fibrous benzoate and purified as indicated, +(b) for the product from the further treatment of (a) as described: + + Found Calc. for + (a) (b) Dinitrate Trinitrate + dinitrobenzoate dinitrobenzoate +Total Nitrogen 7.84 8.97 7.99 9.24 +O.NO_{2} " 5.00 5.45 4.00 5.54 +NO_{2} (Aromatic) 2.84 3.52 3.99 3.70 + +With the two benzoyl groups converted into nitro-benzoyl in each +product, the limit of the ester reaction with the cellulose residue is +reached at the third OH group. + +The nitrogen in the amidobenzoate resulting from the reduction with +ammonium sulphide was 4.5 p.ct.--as against 5.0 p.ct. calculated. The +moisture retained by the fibrous nitrate--nitrobenzoate--in the air-dry +state was found to be 1.97 p.ct. + +The product from the structureless dibenzoate or tetrabenzoate on the +C_{12} formula, was prepared and analysed with the following results: + + Calc. for + Mononitrate tetranitrobenzoate +Total Nitrogen 6.76 7.25 +O.NO_{2} " 1.30 1.45 +NO_{2} " (Aromatic) 5.46 5.80 + +The results were confirmed by the yield of product, viz. 131 p.ct. as +against the calculated 136 p.ct. They afford further evidence of the +generally low limit of esterification of the cellulose molecule. From +the formation of a 'normal' tetracetate--i.e. octacetate of the C_{12} +unit--we conclude that 4/5 of the oxygen atoms are hydroxyl oxygen. Of +the 8 OH groups five only react in the mixed esters described above, and +six only in the case of the simple nitric esters. The ester reactions +are probably not simple, but accompanied by secondary reactions within +the cellulose molecule. + + * * * * * + +(p. 34) ~Cellulose Acetates.~--In the first edition (p. 35) we have +committed ourselves to the statement that 'on boiling cotton with acetic +anhydride and sodium acetate no reaction occurs.' This is erroneous. The +error arises, however, from the somewhat vague statements of +Schutzenberger's researches which are current in the text-books [e.g. +Beilstein, 1 ed. p. 586] together with the statement that reaction only +occurs at elevated temperatures (180°). As a matter of fact, reaction +takes place at the boiling temperature of the anhydride. We have +obtained the following results with bleached cotton: + + Yield Calc. for Monoacetate + C_{6}H_{7}O_{4}O.C_{2}H_{3}O + +Ester reaction 121 p.ct. 125 p.ct. + + {Cellulose 79.9 79.9 +Saponification { + {Acetic acid 29.9 29.4 + +This product is formed without apparent structural alteration of the +fibre. It is entirely insoluble in all the ordinary solvents of the +higher acetates. Moreover, it entirely resists the actions of the +special solvents of cellulose--e.g. zinc chloride and cuprammonium. The +compound is in other respects equally stable and inert. The hygroscopic +moisture under ordinary atmospheric conditions is 3.2 p.ct. + +_Tetracetate._--This product is now made on the manufacturing scale: it +has yet to establish its industrial value. + + +NITRIRUNG VON KOHLENHYDRATEN. + +W. WILL und P. LENZE (Berl. Ber., 1898, 68). + +~NITRATES OF CARBOHYDRATES.~ + +(p. 38) The authors have studied the nitric esters of a typical series +of the now well-defined carbohydrates--pentoses, hexoses, both aldoses +and ketoses--bioses and trioses, the nitrates being prepared under +conditions designed to produce the highest degree of esterification. +Starch, wood, gum, and cellulose were also included in the +investigations. The products were analysed and their physical properties +determined. They were more especially investigated in regard to +temperatures of decomposition, which were found to lie considerably +lower than that of the cellulose nitrates. They also show marked and +variable instability at 50° C. A main purpose of the inquiry was to +throw light upon a probable cause of the instability of the cellulose +nitrates, viz. the presence of nitrates of hydrolysed products or +carbohydrates of lower molecular weight. + +The most important results are these: + +_Monoses._--The _aldoses_ are fully esterified, in the pentoses 4 OH, in +the hexoses 5 OH groups reacting. The pentose nitrates are comparatively +stable at 50°; the hexose nitrates on the other hand are extremely +unstable, showing a loss of weight of 30-40 p.ct. when kept 24 hours at +this temperature. + +Xylose is differentiated by tending to pass into an anhydride form +(C_{5}H_{10}O_{5}-H_{2}O) under this esterification. When treated in +fact with the mixed acids, instead of by the process usually adopted by +the authors of solution in nitric acid and subsequent addition of the +sulphuric acid, it is converted into the dinitrate +C_{5}H_{6}O_{2}.(NO_{3})_{2}. + +_Ketoses_ (C_{6}).--These are sharply differentiated from the corresponding +aldoses by giving _tri_nitrates C_{6}H_{7}O_{2}(NO_{3})_{3} instead +of _penta_nitrates, the remaining OH groups probably undergoing internal +condensation. The products are, moreover, _extremely stable_. It is also +noteworthy that levulose gave this same product, the trinitrate of the +anhydride (levulosan) by both methods of nitration (_supra_). + +_The bisaccharides or bioses_ all give the octonitrates. The degree of +instability is variable. Cane-sugar gives a very unstable nitrate. The +lactose nitrate is more stable. Thus at 50° it loses only 0.7 p.ct. in +weight in eight days; at 75° it loses 1 p.ct. in twenty-four hours, but +with a rapid increase to 23 p.ct. in fifty-four hours. The maltose +octonitrate melts (with decomposition) at a relatively high temperature, +163°-164°. At 50°-75° it behaves much like the lactose nitrate. + +_Trisaccharide._--Raffinose yielded the product + + C_{18}H_{21}O_{5}.(NO_{3})_{11}. + +_Starch_ yields the hexanitrate (C_{12}) by both methods of nitration. +The product has a high melting and decomposing point, viz. 184°, and +when thoroughly purified is quite stable. It is noted that a yield of +157 p.ct. of this nitrate was obtained, and under identical conditions +cellulose yielded 170 p.ct. + +_Wood gum_, from beech wood, gave a tetranitrate (C_{10} formula) +insoluble in all the usual solvents for this group of esters. + +The authors point out in conclusion that the conditions of instability +and decomposition of the nitrates of the monose-triose series are +exactly those noted with the cellulose nitrates as directly prepared and +freed from residues of the nitrating acids. They also lay stress upon +the superior stability of the nitrates of the anhydrides, especially of +the ketoses. + + +NITRATED CARBOHYDRATES AS FOOD MATERIAL FOR MOULDS. + +THOMAS BOKORNY (Chem. Zeit., 1896, 20, 985-986). + +(p. 38) Cellulose trinitrate (nitrocellulose) will serve as a food +supply for moulds when suspended in distilled water containing the +requisite mineral matter and placed in the dark. The growth is rapid, +and a considerable quantity of the vegetable growth accumulates round +the masses of cellulose nitrate, but no growth is observed if mineral +matter is absent. Cellulose itself cannot act as a food supply, and it +seems probable that if glycerol is present cellulose nitrate is no +longer made use of. + + +NITRATION OF CELLULOSE, HYDROCELLULOSE, AND OXYCELLULOSE. + +LEO VIGNON (Compt. rend., 1898, 126, 1658-1661). + +(p. 38) Repeated treatment of cellulose, hydrocellulose, and +oxycellulose with a mixture of sulphuric and nitric acids in large +excess, together with successive analyses of the compounds produced, +showed that the final product of the reaction corresponded, in each +case, with the fixation of 11 NO groups by a molecule containing 24 +atoms of carbon. On exposure to air, nitrohydrocellulose becomes yellow +and decomposes; nitro-oxycellulose is rather more stable, whilst +nitrocellulose is unaffected. The behaviour of these nitro-derivatives +with Schiff's reagent, Fehling's solution, and potash show that all +three possess aldehydic characters, which are most marked in the case of +nitro-oxycellulose. The latter also, when distilled with hydrochloric +acid, yields a larger proportion of furfuraldehyde than is obtained from +nitrocellulose and nitrohydrocellulose. + + * * * * * + +~CELLULOSE NITRATES-EXPLOSIVES.~ + +(p. 38) The uses of the cellulose nitrates as a basis for explosives are +limited by their fibrous character. The conversion of these products +into the structureless homogeneous solid or semi-solid form has the +effect of controlling their combustion. The use of nitroglycerin as an +agent for this purpose gives the curious result of the admixture of two +high or blasting explosives to produce a new explosive capable of +extended use for military purposes. The leading representatives of this +class of propulsive explosives, or 'smokeless powders' are ballistite +and cordite, the technology of which will be found fully discussed in +special manuals of the subject. Since the contribution of these +inventions to the development of cellulose chemistry does not go beyond +the broad, general facts above mentioned, we must refer the reader for +technical details to the manuals in question. + +There are, however, other means of arriving at structureless cellulose +nitrates. One of these has been recently disclosed, and as the results +involve chemical and technical points of novelty, which are dealt with +in a scientific communication, we reproduce the paper in question, +viz.:-- + + +A RE-INVESTIGATION OF THE CELLULOSE NITRATES. + +A. LUCK and C. F. CROSS (J. Soc. Chem. Ind., 1900). + +The starting-point of these investigations was a study of the nitrates +obtained from the structureless cellulose obtained from the +sulphocarbonate (viscose). This cellulose in the form of a fine meal was +treated under identical conditions with a sample of pure cotton +cellulose, viz. digested for 24 hours in an acid mixture containing in +100 parts HNO_{3}--24 : H_{2}SO_{4}--70 : H_{2}O--6: the proportion of +acid to cellulose being 60 : 1--. After careful purification the +products were analysed with the following results: + + Soluble in + Nitrogen Ether alcohol + +Fibrous nitrate 13.31 4.3 p.ct. +Structureless nitrate 13.35 5.6 " + +Examined by the 'heat test' (at 80°) and the 'stability test' (at 135°) +they exhibited the usual instability, and in equal degrees. Nor were the +tests affected by exhaustive treatment with ether, benzene, and alcohol. +From this it appears that the process of solution as sulphocarbonate and +regeneration of the cellulose, though it eliminates certain constituents +of an ordinary bleached cellulose, which might be expected to cause +instability, has really no effect in this direction. It also appears +that instability may be due to by-products of the esterification process +derived from the cellulose itself. + +The investigation was then extended to liquids having a direct solvent +action on these higher nitrates, more especially acetone. It was +necessary, however, to avoid this solvent action proper, and having +observed that dilution with water in increasing proportions produced a +graduated succession of physical changes in the fibrous ester, we +carried out a series of treatments with such diluted acetones. +Quantities of the sample (A), purified as described, but still unstable, +were treated each with five successive changes of the particular liquid, +afterwards carefully freed from the acetone and dried at 40°C. The +products, which were found to be more or less disintegrated, were then +tested by the ordinary heat test, stability test, and explosion test, +with the results shown in the table on next page. + +In this series of trials the sample 'A' was used in the condition of +pulp, viz. as reduced by the process of wet-beating in a Hollander. A +similar series was carried out with the guncotton in the condition in +which it was directly obtained from the ester reaction. The results were +similar to above, fully confirming the progressive character of the +stabilisation with increasing proportions of acetone. These results +prove that washing with the diluted acetone not only rendered the +nitrate perfectly stable, but that the product was more stable than that +obtained by the ordinary process of purification, viz. long-continued +boiling and washing in water. We shall revert to this point after +briefly dealing with the associated phenomenon of structural +disintegration. This begins to be well marked when the proportion of +acetone exceeds 80 p.ct. The optimum effect is obtained with mixtures of +90 to 93 acetone and 10 to 7 water (by volume). In a slightly diluted +acetone of such composition, the guncotton is instantly attacked, the +action being quite different from the gelatinisation which precedes +solution in the undiluted solvent. The fibrous character disappears, and +the product assumes the form of a free, bulky, still opaque mass, which +rapidly sinks to the bottom of the containing vessel. The disintegration +of the bulk of the nitrate is associated with + + __________________________________________________________________________ +| | | | | | +| | Proportions by volume | | | | +| |________________________| Temperature | Heat | Heat | +| | | | of | Test | Test | +| | Acetone | Water | Explosion | 80° | 134° | +|___________________|______________|_________|_____________|_______|_______| +| | | | | | | +| __| | | Deg. | Mins. | Mins. | +| | 20 | 80 | 137 | 3 | 4 | +| | 30 | 70 | 160 | 3 | 4 | +| | 40 | 60 | 180 | 7 | 18 | +| | | | | | No | +| | | | | | fumes | +| | | | | | after | +| From 'A' sample. | 50 | 50 | 187.5 | 55 | 100 | +| | 60 | 40 | 187 | 45 | 100 | +| | 70 | 30 | 185 | 45 | 100 | +| | 80 | 20 | | 50 | 100 | +| __| 92 | 8 | 185 | 50 | 100 | +| | Structure- | | | | | +| | less powder. | | | | | +| " 'B' sample __| 50 | 50 | 183 | 35 | 100 | +| " 'C' sample | Ordinary service | 185 | 10 | 41 | +| | guncotton | | | | +|___________________|______________|_________|_____________|_______|_______| + +a certain solvent action, and on adding an equal bulk of water, the +dissolved nitrate for the most part is precipitated, at the same time +that the undissolved but disintegrated and swollen product undergoes +further changes in the direction of increase of hardness and density. +The product being now collected on a filter, freed from acetone by +washing with water and dried, is a hard and dense powder the fineness of +which varies according to the attendant conditions of treatment. With +the main product in certain cases there is found associated a small +proportion of nitrate retaining a fibrous character, which may be +separated by means of a fine sieve. On examining such a residue, we +found it to contain only 5.6 p.ct. N, and as it was insoluble in strong +acetone, it may be regarded as a low nitrate or a mixture of such with +unaltered cellulose. Confirming this we found that the product passing +through the sieve showed an increase of nitrogen to 13.43 p.ct. from the +13.31 p.ct. in the original. Tested by the heat test (50 minutes) and +stability test (no fumes after 100 minutes), we found the products to +have the characteristics previously noticed. + +It is clear, therefore, that this specifically regulated action of +acetone produces the effects (a) of disintegration, and (b) +stabilisation. It remains to determine whether the latter effect was +due, as might be supposed, to the actual elimination of a compound or +group of compounds present in the original nitrate, and to be regarded +as the effective cause of instability. It is to be noted first that as a +result of the treatment with the diluted acetone and further dilution +after the specific action is completed, collecting the disintegrated +product on a filter and washing with water, the loss of weight sustained +amounts to 3 to 4 p.ct. This loss is due, therefore, to products +remaining dissolved in the filtrate--that is to say, in the much diluted +acetone. These filtrates are in fact opalescent from the presence of a +portion of nitrate in a colloidal (hydrated) form. On distilling off the +acetone, a precipitation is determined. The precipitates are nitrates of +variable composition, analysis showing from 9 to 12 p.ct. of nitric +nitrogen. The filtrate from these precipitates containing only +fractional residues of acetone still shows opalescence. On +long-continued boiling a further precipitation is determined, the +filtrates from which are clear. It was in this final clear filtrate that +the product assumed to cause the instability of the original nitrate +would be present. The quantity, however, is relatively so small that we +have only been able to obtain and examine it as residue from evaporation +to dryness. An exhaustive qualitative examination established a number +of negative characteristics, with the conclusion that the products were +not direct derivatives of carbohydrates nor aromatic compounds. On the +other hand the following positive points resulted. Although the original +diluted acetone extract was neutral to test papers, yet the residue was +acid in character. It contained combined nitric groups, fused below 200° +giving off acid vapours, and afterwards burning with a smoky flame. On +adding lead acetate to the original clear solution, a well-marked +precipitation was determined. The lead compounds thus isolated are +characteristic. They have been obtained in various ways and analysed. +The composition varies with the character of the solution in which the +lead compound is formed. Thus in the opalescent or milky solutions in +which a proportion of cellulose nitrate is held in solution or +semi-solution by the acetone still present, the lead acetate causes a +dense coagulation. The precipitates dried and analysed showed 16-20 +p.ct. PbO and 11-9 p.ct. N. It is clear that the cellulose nitrates are +associated in these precipitates with the lead salts of the acid +compounds in question. When the latter are obtained from clear +solutions, i.e. in absence of cellulose nitrates, they contain 60-63 +p.ct. PbO and 3.5 p.ct. N (obtained as NO). + +In further confirmation of the conclusion from these results, viz. that +the nitrocelluloses with no tendency to combine with PbO are associated +with acid products or by-products of the ester reaction combining with +the oxide, the lead reagent was allowed to react in the presence of 90 +p.ct. acetone. Water was added, the disintegrated mass collected, washed +with dilute acetic acid, and finally with water. Various estimations of +the PbO fixed in this way have given numbers varying from 2 to 2.5 p.ct. +Such products are perfectly stable. This particular effect of +stabilisation appears, therefore, to depend upon the combination of +certain acid products present in ordinary nitrocelluloses with metallic +oxides. In order to further verify this conclusion, standard specimens +of cellulose nitrates have been treated with a large number of metallic +salts under varying conditions of action. It has been finally +established (1) that the effects in question are more particularly +determined by treatment with salts of lead and zinc, and (2) that the +simplest method of treatment is that of boiling the cellulose nitrates +with dilute aqueous solutions of salts of these metals, preferably the +acetates. The following results may be cited, obtained by boiling a +purified 'service' guncotton (sample C) with a 1 p.ct. solution of lead +acetate and of zinc acetate respectively. After boiling 60 minutes the +nitrates were washed free from the soluble metallic salts, dried and +tested. + + __________________________________________________ +| | | | +| | Heat Test | Heat Test | +| | at 80° | at 134° | +|__________________________|___________|___________| +| | | | +| Original sample C | 10 | 41 | +|Treated with lead acetate | 67 | 45 | +| " zinc " | 91 | 45 | +|__________________________|___________|___________| + +In conclusion we may briefly resume the main points arrived at in these +investigations. + +_Causes of instability of cellulose nitrates._--The results of our +experiments so far as to the causes of instability in cellulose nitrates +may be summed up as follows:-- + +(1) Traces of free nitrating acids, which can only occur in the finished +products through careless manufacture, will undoubtedly cause +instability, indicated strongly by the ordinary heat test at 80°, and to +a less extent by the heat test at 134°. + +(2) Other compounds exist in more intimate association with the +cellulose nitrates causing instability which cannot be removed by +exhaustive washing with either hot or cold water, by digestion in cold +dilute alkaline solutions such as sodium carbonate, or by extracting +with ether, alcohol, benzene, &c.; these compounds, however, are soluble +in the solvents of highly nitrated cellulose such as acetone, acetic +ether, pyridine, &c., even when these liquids are so diluted with water +or other non-solvent liquids to such an extent that they have little or +no solvent action upon the cellulose nitrate itself. These solutions +containing the bodies causing instability are neutral to test paper, but +become acid upon evaporation by heating. (This probably explains the +presence of free acid when guncotton is purified by long-continued +boiling in water without any neutralising agent being present.) + +(3) The bodies causing instability are products or by-products of the +original ester reaction, acid bodies containing nitroxy-groups, but +otherwise of ill-defined characteristics. They combine with the oxides +of zinc or lead, giving insoluble compounds. They are precipitated from +their solutions in diluted acetone upon the addition of soluble salts of +these metals. + +(4) Cellulose nitrates are rendered stable either by eliminating these +compounds, or by combining them with the oxides of lead or zinc whilst +still in association with cellulose nitrates. + +(5) Even the most perfectly purified nitrocellulose will slowly +decompose with formation of unstable acid products by boiling for a long +time in water. This effect is much more apparent at higher temperatures. + +_Dense structureless or non-fibrous cellulose nitrates_ can be +industrially prepared (1) by nitrating the amorphous forms of cellulose +obtained from its solution as sulphocarbonate (viscose). The cellulose +in this condition reacts with the closest similarity to the original +fibrous cellulose; the products are similar in composition and +properties, including that of instability. + +(2) By treating the fibrous cellulose nitrates with liquid solvents of +the high nitrate diluted with non-solvent liquids, and more especially +water. The optimum effect is a specific disintegration or breaking down +of their fibrous structure quite distinct from the gelatinisation which +precedes solution in the undiluted solvent, and occurring within narrow +limits of variation in the proportion of the diluting and non-solvent +liquid--for industrial work the most convenient solution to employ is +acetone diluted with about 10 p.ct. of water by volume. + +The industrial applications of these results are the basis of English +patents 5286 (1898), 18,868 (1898), 18,233 (1898), Luck and Cross (this +Journal, 1899, 400, 787). + +The structureless guncotton prepared as above described is of quite +exceptional character, and entirely distinct from the ordinary fibrous +nitrate or the nitrate prepared by precipitation from actual solution in +an undiluted solvent.[3] By the process described, the nitrate is +obtained at a low cost in the form of a very fine, dense, structureless, +white powder of great purity and stability, entirely free from all +mechanical impurities. The elimination of these mechanical impurities, +and also to a very great extent of coloured compounds contained in the +fibrous nitrate, makes the product also useful in the manufacture of +celluloids, artificial silk, &c., whilst its very dense form gives it a +great advantage over ordinary fibrous guncotton for use in shells and +torpedoes, and for the manufacture of gelatinised gunpowders, &c. It can +be compressed with ease into hard masses; and experiments are in +progress with a view of producing from it, in admixture with 'retaining' +ingredients, a military explosive manufactured by means of ordinary +black gunpowder machinery and processes. + +_Manufacture of sporting powder._--The fact that the fibrous structure +of ordinary guncotton or other cellulose nitrate can be completely or +partially destroyed by treatment with diluted acetone and without +attendant solution, constitutes a process of value for the manufacture +of sporting powder having a base of cellulose nitrate of any degree of +nitration. The following is a description of the hardening process. + +'Soft grains' are manufactured from ordinary guncotton or other +cellulose nitrate either wholly or in combination with other +ingredients, the process employed being the usual one of revolving in a +drum in the damp state and sifting out the grains of suitable size after +drying. These grains are then treated with diluted acetone, the degree +of dilution being fixed according to the hardness and bulk of the +finished grain it is desired to produce (J. Soc. Chem. Ind., 1899, 787). +Owing to the wide limits of dilution and corresponding effect, the +process allows of the production of either a 'bulk' or a 'condensed' +powder. + +We prefer to use about five litres of the liquid to each one kilo. of +grain operated upon, as this quantity allows of the grains being freely +suspended in the liquid upon stirring. The grains are run into the +liquid, which is then preferably heated to the boiling-point for a few +minutes whilst the whole is gently stirred. Under this treatment the +grains assume a more or less rounded gelatinous condition according to +the strength of the liquid. There is, however, no solution of the +guncotton and practically no tendency of the grains to cohere. Each +grain, however, is acted upon _throughout_ and perfectly _equally_. +After a few minutes' treatment, water is gradually added, when the +grains rapidly harden. They are then freed from acetone and certain +impurities by washing with water, heating, and drying. The process is of +course carried out in a vessel provided with any means for gentle +stirring and heating, and with an outlet for carrying off the +volatilised solvent which is entirely recovered by condensation, the +grains parting with the acetone with ease. + +_Stabilising cellulose nitrates._--The process is of especial value in +rendering stable and inert the traces of unstable compounds which always +remain in cellulose nitrate after the ordinary boiling and washing +process. It is of greatest value in the manufacture of collodion cotton +used for the preparation of gelatinous blasting explosives and all +explosives composed of nitroglycerin and cellulose nitrates. Such +mixtures seem peculiarly liable to decomposition if the cellulose +nitrate is not of exceptional stability (J. Soc. Chem. Ind., 1899, +787). + + +EMPLOI DE LA CELLULOSE POUR LA FABRICATION DE FILS BRILLANTS IMITANT LA +SOIE. + +E. BRONNERT (1) (Rev. Mat. Col., 1900, September, 267). + +V. ~USE OF CELLULOSE IN THE MANUFACTURE OF IMITATIONS OF SILK +(LUSTRA-CELLULOSE).~ + +(p. 45) _Introduction._--The problem of spinning a continuous thread of +cellulose has received in later years several solutions. Mechanically +all resolve themselves into the preparation of a structureless filtered +solution of cellulose or a cellulose derivative, and forcing through +capillary orifices into some medium which either absorbs or decomposes +the solvent. The author notes here that the fineness and to a great +extent the softness of the product depends upon the dimensions of the +capillary orifice and concentration of the solution. The technical idea +involved in the spinning of artificial fibres is an old one. Réaumur (2) +forecast its possibility, Audemars of Lausanne took a patent as early as +1855 (3) for transforming nitrocellulose into fine filaments which he +called 'artificial silk.' The idea took practical shape only when it +came to be used in connection with filaments for incandescent lamps. In +this connection we may mention the names of the patentees:--Swinburne +(4), Crookes, Weston (5), Swan (6), and Wynne and Powell (7). These +inventors prepared the way for Chardonnet's work, which has been +followed since 1888 with continually increasing success. + +At this date the lustra-celluloses known may be divided into four +classes. + +1. 'Artificial silks' obtained from the nitrocelluloses. + +2. 'Lustra-cellulose' made from the solution of cellulose in +cuprammonium. + +3. 'Lustra-cellulose' prepared from the solution of cellulose in +chloride of zinc. + +4. 'Viscose silks,' by the decomposition of sulphocarbonate of cellulose +(Cross and Bevan). + +GROUP 1. The early history of the Chardonnet process is discussed and +some incidental causes of the earlier failures are dealt with. The +process having been described in detail in so many publications the +reader is referred to these for details. [See Bibliography, (1) and (2), +(3) and (4).] The denitrating treatment was introduced in the period +1888-90 and of course altogether changed the prospects of the industry; +not only does it remove the high inflammability, but adds considerably +to softness, lustre, and general textile quality. In Table I will be +found some important constants for the nitrocellulose fibre; also the +fibre after denitration and the comparative constants for natural silk. + +TABLE 1. + + _______________________________________________________________________ +| | | | +| | Tenacity | Elasticity | +| | (grammes) | (% elongation) | +|__________________________________________|___________|________________| +| | | | +| Nitrocellulose according to Chardonnet | | | +| German Patent No. 81,599 | 150 | 23 | +| The same after denitration | 110 | 8 | +| Denitrated fibre moistened with water | 25 | -- | +| Nitrocellulose: Bronnert's German Patent | | | +| No. 93,009 | 125 | 28 | +| The same after denitration (dry) | 115 | 13 | +| The same after denitration (wetted) | 32 | -- | +| Natural silk | 300 | 18 | +|__________________________________________|___________|________________| + + 1. Tenacity is the weight in grammes required to break the + thread. + + 2. Elasticity is the elongation per cent. at breaking. + + The numbers are taken for thread of 100 deniers (450 metres of + 0.05 grammes = 1 denier). It must be noted that according to + the concentration of the solution and variations in the process + of denitration the constants for the yarn are subject to very + considerable variation. + +In regard to the manufacture a number of very serious difficulties have +been surmounted. First, instead of drying the nitrated cellulose, which +often led to fires, &c., it was found better to take it moist from the +centrifugal machine, in which condition it is dissolved (5). It was +next found that with the concentrated collodion the thread could be spun +direct into the air, and the use of water as a precipitant was thus +avoided. + +With regard to denitration which is both a delicate and disagreeable +operation: none of the agents recommended to substitute the sulphydrates +have proved available. Of these the author mentions ferrous chloride +(6), ferrous chloride in alcohol (7), formaldehyde (8), +sulphocarbonates. The different sulphydrates (9) have very different +effects. The calcium compound tends to harden and weaken the thread. The +ammonia compound requires great care and is costly. The magnesium +compound works rapidly and gives the strongest thread. Investigations +have established the following point. In practice it is not necessary to +combine the saponification of cellulose ester with complete reduction of +the nitric acid split off. The latter requires eight molecules of +hydrogen sulphide per one molecule tetranitrocellulose, but with +precautions four molecules suffice. It is well known that the +denitration is nearly complete, traces only of nitric groups surviving. +Their reactions with diphenylamine allow a certain identification of +artificial silks of this class. Various other inventors, e.g. Du Vivier +(10), Cadoret (11), Lehner (12), have attempted the addition of other +substances to modify the thread. These have all failed. Lehner, who +persisted in his investigations, and with success, only attained this +success, however, by leaving out all such extraneous matters. Lehner +works with 10 p.ct. solutions; Chardonnet has continually aimed at +higher concentration up to 20 p.ct. Lehner has been able very much to +reduce his pressures of ejection in consequence; Chardonnet has had to +increase up to pressures of 60 k. per cm. and higher. The latter +involves very costly distributing apparatus. Lehner made next +considerable advance by the discovery of the fact that the addition of +sulphuric acid to the collodion caused increase of fluidity (13), which +Lehner attributes to molecular change. Chardonnet found similar results +from the addition of aldehyde and other reagents (14), but not such as +to be employed for the more concentrated collodions. The author next +refers to his discoveries (15) that alcoholic solutions of a number of +substances, organic and inorganic, freely dissolve the lower cellulose +nitrates. The most satisfactory of these substances is chloride of +calcium (16). It is noted that acetate of ammonia causes rapid changes +in the solution, which appear to be due to a species of hydrolysis. The +result is sufficiently remarkable to call for further investigation. The +chloride of calcium, it is thought possible, produces a direct +combination of the alcohol with a reactive group of the nitrocellulose. +The fluidity of this solution using one mol. CaCl_{2} per 1 mol. +tetranitrate (17) reaches a maximum in half an hour's heating at +60°-70°C. The fluidity is increased by starting from a cotton which has +been previously mercerised. After nitration there is no objection to a +chlorine bleach. Chardonnet has found on the other hand that in +bleaching before nitration there is a loss of spinning quality in the +collodion. The author considers that the new collodion can be used +entirely in place of the ordinary ether-alcohol collodion. With regard +to the properties of the denitrated products they fix all basic colours +without mordant and may be regarded as oxycellulose therefore. The +density of the thread is from 1.5 to 1.55. The thread of 100 deniers +shows a mean breaking strain of 120 grammes with an elasticity of 8-12 +p.ct. The cardinal defect of these fibres is their property of +combination with water. Many attempts have been made to confer +water-resistance (18), but without success. Strehlenert has proposed the +addition of formaldehyde (19), but this is without result (20). In +reference to these effects of hydration, the author has made +observations on cotton thread, of which the following table represents +the numerical results: + + Breaking Strain + Mean of 20 experiments + +Skein of bleached cotton without treatment 825 +Skein of bleached cotton without treatment, but wetted 942 +Ditto after conversion into hexanitrate, dry 884 +The above, wetted 828 +The cotton denitrated from above, dry 529 +The cotton denitrated as above and wetted 206 + +The author considers that other patents which have been taken for +spinning nitrocellulose are of little practical account (21) and (22). +The same conclusion also applies to the process of _Langhans_, who +proposes to spin solutions of cellulose in sulphuric acid (23) (24) and +mixtures of sulphuric acid and phosphoric acid. + +GROUP 2. _Lustra-cellulose._--Thread prepared by spinning solutions of +cellulose in cuprammonium. + +This product is made by the Vereinigte Glanzstoff-Fabriken, Aachen, +according to a series of patents under the names of H. Pauly, M. Fremery +and Urban, Consortium mulhousien pour la fabrication de fils brillants, +E. Bronnert, and E. Bronnert and Fremery and Urban (1). The first patent +in this direction was taken by Despeissis in 1890 (2). It appears this +inventor died shortly after taking the patent (3) The matter was later +developed by Pauly (4) especially in overcoming the difficulty of +preparing a solution of sufficient concentration. (It is to be noted +that Pauly's patents rest upon a very slender foundation, being +anticipated in every essential detail by the previous patent of +Despeissis.) For this very great care is required, especially, first, +the condition of low temperature, and, secondly, a regulated proportion +of copper and ammonia to cellulose. The solution takes place more +rapidly if the cellulose has been previously oxidised. Such cellulose +gives an 8 p.ct. solution, and the thread obtained has the character of +an oxycellulose, specially seen in its dyeing properties. The best +results are obtained, it appears, by the preliminary mercerising +treatment and placing the alkali cellulose in contact with copper and +ammonia. (All reagents employed in molecular proportions.) The author +notes that the so-called hydrocellulose (Girard) (5) is almost insoluble +in cuprammonium, as is starch. It is rendered soluble by alkali +treatment. + +GROUP 3. _Lustra-cellulose_ prepared by spinning a solution of cellulose +in concentrated chloride of zinc. + +This solution has been known for a long time and used for making +filaments for incandescent lamps. The cellulose threads, however, have +very little tenacity. This is no doubt due to the conditions necessary +for forming the solution, the prolonged digestion causing powerful +hydrolysis (1). Neither the process of Wynne and Powell (2) nor that of +Dreaper and Tompkins (3), who have endeavoured to bring the matter to a +practical issue, are calculated to produce a thread taking a place as a +textile. The author has described in his American patent (4) a method of +effecting the solution in the cold, viz. again by first mercerising the +cellulose and washing away the caustic soda. This product dissolves in +the cold and the solution remains unaltered if kept at low temperature. +Experiments are being continued with these modifications of the process, +and the author anticipates successful results. The modifications having +the effect of maintaining the high molecular weight of the cellulose, it +would appear that these investigations confirm the theory of Cross and +Bevan that the tenacity of a film or thread of structureless regenerated +cellulose is directly proportional to the molecular weight of the +cellulose, i.e. to its degree of molecular aggregation (5). + +GROUP 4. 'Viscose' silks obtained by spinning solutions of xanthate of +cellulose. + +In 1892, Cross and Bevan patented the preparation of a new and curious +compound of cellulose, the thiocarbonate (1) (2) (3). Great hopes were +based upon this product at the time of its discovery. It was expected +to yield a considerable industrial and financial profit and also to +contribute to the scientific study of cellulose. The later patents of C. +H. Stearn (4) describe the application of viscose to the spinning of +artificial silk. The viscose is projected into solutions of chloride of +ammonium and washed in a succession of saline solutions to remove the +residual sulphur impurities. The author remarks that though it has a +certain interest to have succeeded in making a thread from this compound +and thus adding another to the processes existing for this purpose, he +is not of opinion that it shows any advance on the lustra-cellulose (2) +and (3). He also considers that the bisulphide of carbon, which must be +regarded as a noxious compound, is a serious bar to the industrial use +of the process, and for economic work he considers that the regeneration +of ammonia from the precipitating liquors is necessary and would be as +objectionable as the denitration baths in the collodion process. The +final product not being on the market he does not pronounce a finally +unfavourable opinion. + +The author and the Vereinigte Glanzstoff-Fabriken after long +investigation have decided to make nothing but the lustra-cellulose (2) +and (3). A new factory at Niedermorschweiler, near Mulhouse, is +projected for this last production. + + +BIBLIOGRAPHY + +_Introduction_ + +(1) Bull. de la Soc. industr. de Mulhouse, 1900. + +(2) Réaumur, Mémoire pour servir à l'histoire des insectes, 1874, 1, p. +154. + +(3) English Pat. No. 283, Feb. 6, 1855. + +(4) Swinburne, Electrician, 18, 28, 1887, p. 256. + +(5) Weston (Swinburne), Electrician, 18, 1887, p. 287. Eng. Pat. No. +22866, Sept. 12, 1882. + +(6) German Pat. No. 3029. English Pat. No. 161780, April 28, 1884 +(Swan). + +(7) Wynne-Powell, English Pat. No. 16805, Dec. 22, 1884. + + +_Group I_ + +(1) German Pat No. 38368, Dec. 20, 1885. German Pat. No. 46125, March 4, +1888. German Pat. No. 56331, Feb. 6, 1890. German Pat. No. 81599, Oct. +11, 1893. German Pat. No. 56655, April 23, 1890. French Pat. No. 231230, +June 30, 1893. + +(2) Industrie textile, 1899, 1892. Wyss-Noef, Zeitschrift für angewandte +Chemie, 1899, 30, 33. La Nature, Jan. 1, 1898, No. 1283. Revue générale +des sciences, June 30, 1898. + +(3) German Pat. No. 46125, March 4, 1888. German Pat. No. 56655, April +23, 1890. + +(4) Swan, English Pat. 161780, June 28, 1884. See also Béchamp, Dict. de +Chimie de Wurtz. + +(5) German Pat. No. 81599, Oct 11, 1893. + +(6) Béchamp, art. Cellulose, Dict. de Chimie de Wurtz, p. 781. + +(7) Chardonnet, addit. March 3, 1897, to the French Pat. 231230, May 30, +1893. + +(8) Knofler, French Pat. 247855, June 1, 1895. German Pat. 88556, March +28, 1894. + +(9) Béchamp, art. Cellulose, Dict. de Chimie de Wurtz. Blondeau, Ann. +Chim. et Phys. (3), 1863, 68, p. 462. + +(10) Revue industrielle, 1890, p. 194. German Pat. 52977, March 7, 1889. + +(11) French Pat. 256854, June 2, 1896. + +(12) German Pat. 55949, Nov. 9, 1889. German Pat. 58508, Sept. 16, 1890. +German Pat. 82555, Nov. 15, 1894. + +(13) German Pat. 58508, Sept. 16, 1900. + +(14) French Pat. 231230, June 30, 1893. + +(15) German Pat. 93009, Nov. 19, 1895. French Pat. 254703, March 12, +1896. English Pat. 6858, March 28, 1896. + +(16) American Pat. 573132, Dec. 15, 1896. + +(17) This proportion is the most advantageous, and furnishes the best +liquid collodions that can be spun. + +(18) French Pat. 259422, Sept. 3, 1896. + +(19) English Pat. 22540, 1896. + +(20) Application for German Pat. not granted, 4933 IV. 296, Mar. 16, +1897. + +(21) German Pat. 96208, Feb. 10, 1897. Addit. Pat. 101844 and 102573, +Dec. 10, 1897. + +(22) Oberle et Newbold, French Pat. 25828, July 22, 1896. Granquist, +Engl. applic. 2379, Nov. 28, 1899. + +(23) German Pat. 72572, June 17, 1891. + +(24) Voy. Stern, Ber., 28, ch. 462. + + +_Group II_ + +(1) German Pat. 98642, Dec. 1, 1897 (Pauly). French Pat. 286692, March +10, 1899, and addition of October 14, 1899 (Fremery and Urban). French +Pat. 286726, March 11, 1899, and addition of December 4, 1899. German +Pat. 111313, March 16, 1899 (Fremery and Urban). English Pat. 18884, +Sept. 19, 1899 (Bronnert). English Pat. 13331, June 27, 1899 (Consort. +mulhousien). + +(2) French Pat. 203741, Feb. 12, 1890. + +(3) The actual lapse of this patent is due to the death of Despeissis +shortly after it was taken. + +(4) Without questioning the good faith of Pauly, it is nevertheless a +fact that the original patent remains as a document, and therefore that +the value of the Pauly patents is very questionable. + +(5) Girard, Ann. Chim. et Phys, 1881 (5), 24, p. 337-384. + + +_Group III_ + +(1) Cross and Bevan, Cellulose, 1895, p. 8. + +(2) English Pat. 16805, Dec. 22, 1884. + +(3) English Pat. 17901, July 30, 1897. + +(4) Bronnert, American Pat. 646799, April 3, 1900. + +(5) Cross and Bevan, Cellulose, 1895, p. 12. + + +_Group IV_ + +(1) English Pat. 8700, 1892. German Pat. 70999, Jan. 13, 1893. + +(2) English Pat. 4713, 1896. German Pat. 92590, Nov. 21, 1896. + +(3) Comptes rendus (loc. cit.). Berichte, c. 9, 65a. + +(4) English Pat. 1020, 1898. German Pat. 108511, Oct. 18, 1898. + + +~Artificial Silk--Lustra-cellulose.~ + +C. F. CROSS and E. J. BEVAN (J. Soc. Chem. Ind., 1896, 317). + +The object of this paper is mainly to correct current statements as to +the artificial or 'cellulose silks' being explosive or highly +inflammable (ibid., 1895, 720). A specimen of the 'Lehner' silk was +found to retain only 0.19 p.ct. total nitrogen, showing that the +denitration is sufficiently complete to dispose of any suggestion of +high inflammability. + +The product yielded traces only of furfural; on boiling with a 1 p.ct. +solution of sodium hydrate, the loss of weight was 9.14 p.ct.; but the +solution had no reducing action on Fehling's solution. The product in +denitration had therefore reverted completely to a cellulose (hydrate), +no oxy-derivative being present. + + * * * * * + +The authors enter a protest against the term 'artificial silk' as +applied to these products, and suggest 'lustra-cellulose.' + + +DIE KÜNSTLICHE SEIDE-IHRE HERSTELLUNG, EIGENSCHAFTEN UND VERWENDUNG. + +CARL SÜVERN, Berlin, 1900, J. Springer. + +~ARTIFICIAL SILK--ITS PRODUCTION, PROPERTIES, AND APPLICATIONS.~ + +This work of some 130 pages is an important monograph on the subject of +the preparation of artificial cellulose threads--so far as the technical +elements of the problems involved are discussed and disclosed in the +patent literature. The first section, in fact, consists almost +exclusively of the several patent specifications in chronological order +and ranged under the sub-sections: (a) The Spinning of Nitrocellulose +(collodion); (b) The Spinning of other Solutions of Cellulose; (c) +The Spinning of Solutions of the Nitrogenous Colloids. + +In the second section the author deals with the physical and chemical +proportions of the artificial threads. + +_Chardonnet 'silk'_ is stated to have a mean diameter of 35µ, but with +considerable variations from the mean in the individual fibres; equally +wide variations in form are observed in cross-section. The general form +is elliptical, but the surface is marked by deep striæ, and the +cross-section is therefore of irregular outline. This is due to +irregular conditions of evaporation of the solvents, the thread being +'spun' into the air from cylindrical orifices of regulated dimensions. +Chardonnet states that when the collodion is spun into alcohol the +resultant thread is a perfect cylinder (Compt. rend. 1889, 108, 962). +The strength of the fibre is variously stated at from 50-80 p.ct. that +of 'boiled off' China tram; the true elasticity is 4-5 p.ct., the +elongation under the breaking strain 15-17 p.ct. The sp.gr. is 1.49, +i.e. 3-5 p.ct. in excess of boiled off silk. + +_Lehner 'silk'_ exhibits the closest similarity to the Chardonnet +product. In cross-section it is seen to be more regular in outline, and +a round, pseudo-tubular form prevails, due to the conditions of +shrinkage and collapse of the fibre in parting with the solvents, and in +then dehydrating. The constants for 'breaking strain,' both in the +original and moistened condition, for elasticity, &c., are closely +approximate to those for the Chardonnet product. + +_Pauly 'silk'._--The form of the ultimate fibres is much more regular +and the contour of the cross-section is smooth. The product shows more +resistance to moisture and to alkaline solutions. + +_Viscose 'silk'_ is referred to in terms of a communication appearing in +'Papier-Zeitung,' 1898, 2416. + + In the above section the following publications are referred + to: Chardonnet, 'Compt. rend.,' 1887, 105, 900; and 1889, 108, + 962; Silbermann, 'Die Seide,' 1897, v. 2, 143; Herzog, + 'Farber-Zeitung,' 1894/5, 49-50; Thiele, ibid. 1897, 133; O. + Schlesinger, 'Papier-Zeitung,' 1895, 1578-81, 1610-12. + + +_Action of Reagents upon Natural and Artificial Silks._ + +1. _Potassium hydrate_ in solution of maximum concentration dissolves +the silks proper, (a) China silk on slight warming, (b) Tussah silk +on boiling. The cellulose 'silks' show swelling with discolouration, but +the fibrous character is not destroyed even on boiling. + +2. _Potassium hydrate_ 40 p.ct. China silk dissolves completely at +65°-85°; Tussah silk swells considerably at 75° and dissolves at +100°-120°. The cellulose 'silks' are attacked with discolouration; at +140° (boiling-point of the solution) there is progressive solvent +action, but the action is incomplete. The Pauly product is most +resistant. + +3. _Zinc chloride_, 40 p.ct. solution. Both the natural silks and +lustra-celluloses are attacked at 100°, and on raising the temperature +the further actions are as follows: China silk is completely dissolved +at 110-120°; Tussah silk at 130-135°; the collodion products at +140-145°; the Pauly product was again most resistant, dissolving at +180°. + +4. _Alkaline cupric oxide_ (glycerin) solution was prepared by +dissolving 10 grs. of the sulphate in 100 c.c. water, adding 5 grs. +glycerin and 10 c.c. of 40 p.ct. KOH. In this solution the China silk +dissolved at the ordinary temperature; Tussah silk and the +lustra-celluloses were not appreciably affected. + +5. _Cuprammonium solution_ was prepared by dissolving the precipitated +cupric hydrate in 24 p.ct. ammonia. In this reagent also the China silk +dissolved, and the Tussah silk as well as the lustra-celluloses +underwent no appreciable change. + +6. _An ammoniacal solution of nickel oxide_ was prepared by dissolving +the precipitated hydrated oxide in concentrated ammonia. The China silk +was dissolved by this reagent; Tussah silk and the lustra-celluloses +entirely resisted its action. + +7. _Fehling's solution_ is a solvent of the natural silks, but is +without action on the lustra-celluloses. + +8. _Chromic acid_--20 p.ct. CrO_{3}--solution dissolves both the natural +silks and the lustra-celluloses at the boiling temperature of the +solution. + +9. _Millon's reagent_, at the boiling solution, colours the natural +silks violet: the lustra-celluloses give no reaction. + +10. _Concentrated nitric acid_ attacks the natural silks powerfully in +the cold; the lustra-celluloses dissolve on heating. + +11. _Iodine solution_ (I in KI) colours the China silk a deep brown, +Tussah a pale brown; the celluloses from collodion are coloured at first +brown, then blue. The Pauly product, on the other hand, does not react. + +12. _Diphenylamine sulphate._--A solution of the base in concentrated +sulphuric acid colours the natural silks a brown; the collodion 'silks' +give a strong blue reaction due to the presence of residual +nitro-groups. The Pauly product is not affected. + +13. _Brucin sulphate_ in presence of concentrated sulphuric acid colours +the natural silks only slightly (brown); the collodion 'silks' give a +strong red colouration. The Pauly product again is without reaction. + +14. _Water._--The natural silks do not soften in the mouth as do the +lustra-celluloses. + +15. _Water of condition_ was determined by drying at 100°; the following +percentages resulted (a). The percentages of water (b) taken up from +the atmosphere after forty-three hours' exposure were: + + (a) (b) + China (raw) silk 7.97 2.24 + Tussah silk 8.26 5.00 + + Lustra-celluloses: + + Chardonnet (Besançon) 10.37 5.64 + " Spreitenbach 11.17 5.77 + Lehner 10.71 5.97 + Pauly 10.04 6.94 + +16. _Behaviour on heating at 200°._--After two hours' heating at this +temperature the following changes were noted: + + China silk Much discoloured (brown). + Tussah silk Scarcely affected. + +Lustra-celluloses: + + Chardonnet Converted into a blue-black charcoal, retaining the + Lehner form ofthe fibres. + + Pauly A bright yellow-brown colouration, without carbonisation. + +17. The _losses of weight_ accompanying these changes and calculated per +100 parts of fibre dried at 100° were: + + China silk 3.18 + Tussah silk 2.95 + +Lustra-celluloses: + + Chardonnet 33.70 + Lehner 26.56 + Pauly 1.61 + +18. _Inorganic constituents._--Determinations of the total ash gave for +the first five of the above, numbers varying from 1.0 to 1.7 p.ct. The +only noteworthy point in the comparison was the exceptionally small ash +of the Pauly product, viz. 0.096 p.ct. + +19. _Total nitrogen._--The natural silks contain the 16-17 p.ct. N +characteristic of the proteids. The lustra-celluloses contain 0.05-0.15 +p.ct. N which in those spun from collodion is present in the form of +nitric groups. + +The points of chemical differentiation which are established by the +above scheme of comparative investigation are summed up in tabular form. + +_Methods of dyeing._--The lustra-celluloses are briefly discussed. The +specific relationship of these forms of cellulose to the colouring +matters are in the main those of cotton, but they manifest in the +dye-bath the somewhat intensified attraction which characterises +mercerised cotton, or more generally the cellulose hydrates. + +_Industrial applications_ of the lustra-celluloses are briefly noticed +in the concluding section of the book. + +FOOTNOTES: + +[3] With these products it is easy to observe that they have a definite +fusion point 5°-10° below the temperature of explosion. + + + + +SECTION III. DECOMPOSITIONS OF CELLULOSE SUCH AS THROW LIGHT ON THE +PROBLEM OF ITS CONSTITUTION + + +UEBER CELLULOSE. + +G. BUMCKE und R. WOLFFENSTEIN (Berl. Ber., 1899, 2493). + +(p. 54) _Theoretical Preface._--The purpose of these investigations is +the closer characterisation of the products known as 'oxycellulose' and +'hydracellulose,' which are empirical aggregates obtained by various +processes of oxidation and hydrolysis; these processes act concurrently +in the production of the oxycelluloses. The action of hydrogen peroxide +was specially investigated. An oxycellulose resulted possessing strongly +marked aldehydic characteristics. The authors commit themselves to an +explanation of this paradoxical result, i.e. the production of a body +of strongly 'reducing' properties by the action of an oxidising agent +upon the inert cellulose molecule (? aggregate) as due to the +_hydrolytic_ action of the peroxide: following Wurster (Ber. 22, 145), +who similarly explained the production of reducing sugars from cane +sugar by the action of the peroxide. + +The product in question is accordingly termed _hydralcellulose_. By the +action of alkalis this is resolved into two bodies of alcoholic +(cellulose) and acid ('acid cellulose') characteristics respectively. +The latter in drying passes into a lactone. The acid product is also +obtained from cellulose by the action of alkaline lye (boiling 30 p.ct. +NaOH) and by solution in Schweizer's reagent. + +It is considered probable that the cellulose nitrates are hydrocellulose +derivatives, and experimental evidence in favour of this conclusion is +supplied by the results of 'nitrating' the celluloses and their oxy- and +hydro- derivatives. Identical products were obtained. + +_Experimental investigations._--The filter paper employed as 'original +cellulose,' giving the following numbers on analysis: + + C 44.56 44.29 44.53 44.56 + H 6.39 6.31 6.46 6.42 + +was exposed to the action of pure distilled H_{2}O_{2} at 4-60 p.ct. +strength, at ordinary temperatures until disintegrated: a result +requiring from nineteen to thirty days. The series of products gave the +following analytical results: + + C 43.61 43.61 43.46 43.89 44.0 43.87 43.92 43.81 + H 6.00 6.29 6.28 6.26 6.13 6.27 6.24 6.27 + +results lying between the requirements of the formulæ: + + 5 C_{6}H_{10}O_{5}.H_{2}O and 8 C_{6}H_{10}O_{5}.H_{2}O. + +Hydrazones were obtained with 1.7-1.8 p.ct. N. Treated with caustic soda +solution the hydrazones were dissolved in part: on reprecipitation a +hydrazone of unaltered composition was obtained. The original product +shows therefore a uniform distribution of the reactive CO- groups. + +The hydralcellulose boiled with Fehling's solution reduced 1/12 of the +amount required for an equal weight of glucose. + +Digested with caustic soda solution it yielded 33 p.ct. of its weight of +the soluble 'acid cellulose.' This product was purified and analysed +with the following result: C 43.35 H 6.5. For the direct production of +the 'acid' derivative, cellulose was boiled with successive quantities +of 30 p.ct. NaOH until _dissolved_. It required eight treatments of one +hour's duration. On adding sulphuric acid to the solutions the product +was precipitated. Yield 40 p.ct. Analyses: + + C 43.8 43.8 43.7 + H 6.2 6.2 6.3 + +The cellulose reprecipitated from solution in Schweizer's reagent gave +similar analytical results: + + C 43.9 43.8 44.0 + H 6.5 6.3 6.4 + +_Conversion into nitrates._--The original cellulose, hydral- and acid +cellulose were each treated with 10 times their weight of HNO_{3} of +1.48 sp.gr. and heated at 85° until the solution lost its initial +viscosity. + +The products were precipitated by water and purified by solution in +acetone from which two fractions were recovered, the one being +relatively insoluble in ethyl alcohol. The various nitrates from the +several original products proved to be of almost identical composition, + + C 32.0 H 4.2 N 8.8 + +with a molecular weight approximately 1350. The conclusion is that +these products are all derivatives of a 'hydralcellulose' +6C_{6}H_{10}O_{5}H_{2}O. + + +FORMATION OF FURFURALDEHYDE FROM CELLULOSE, OXYCELLULOSE, AND +HYDROCELLULOSE. + +By LEO VIGNON (Compt. rend., 1898, 126, 1355-1358). + +(p. 54) Hydrocellulose, oxycellulose, and 'reduced' cellulose, the last +named being apparently identical with hydrocellulose, were obtained by +heating carefully purified cotton wool (10 grams) in water (1,000 c.c.), +with (1) 65 c.c. of hydrochloric acid (1.2 sp.gr.), (2) 65 c.c. of +hydrochloric acid and 80 grams of potassium chlorate, (3) 65 c.c. of +hydrochloric acid and 50 grams of stannous chloride. From these and some +other substances, the following percentage yields of furfuraldehyde were +obtained: Hydrocellulose, 0.854; oxycellulose, 2.113; reduced cellulose, +0.860; starch, 0.800; bleached cotton, 1.800; oxycellulose, prepared by +means of chromic acid, 3.500. Two specimens of oxycellulose were +prepared by treating cotton wool with hydrochloric acid and potassium +chlorate (A), and with sulphuric acid and potassium dichromate (B), and +25 grams of each product digested with aqueous potash. Of the product A, +16.20 grams were insoluble in potash, 2.45 grams were precipitated on +neutralisation of the alkaline solution, and 6.35 grams remained in +solution, whilst B yielded 11.16 grams of insoluble matter, 1.42 grams +were precipitated by acid, and 12.42 grams remained in solution. The +percentage yields of furfuraldehyde obtained from these fractions were +as follows: A, insoluble, 0.86; precipitated, 4.35; dissolved, 1.10. B, +insoluble, 0.76; precipitated, 5.11; dissolved, 1.54. It appears, from +the foregoing results, that the cellulose molecule, after oxidation, is +easily decomposed by potash, the insoluble and larger portion having all +the characters of the original cellulose, whilst the soluble portion is +of an aldehydic nature, and contains a substance, precipitable by acids, +which yields a relatively large amount of furfuraldehyde. + + +UNTERSUCHUNGEN ÜBER DIE OXYCELLULOSE. + +O. V. FABER und B. TOLLENS (Berl. Ber., 1899, 2589). + +~Investigations of Oxycellulose.~ + +(p. 61) The author's results are tersely summed up in the following +conclusions set forth at the end of the paper: The oxycelluloses are +mixtures of cellulose and a derivative oxidised compound which contains +one more atom O than cellulose (cellulose = C_{6}H_{10}O_{5}), and for +which the special designation _Celloxin_ is proposed. + +Celloxin may be formulated C_{8}H_{6}O_{6} or C_{6}H_{10}O_{6}, of which +the former is the more probable. + +The various oxycelluloses may be regarded as containing one celloxin +group to 1-4 cellulose groups, according to the nature of the original +cellulose, and the degree of oxidation to which subjected. These groups +are in chemical union. + +Celloxin has not been isolated. On boiling the oxycelluloses with +lime-milk it is converted into isosaccharinic and dioxybutyric acids. +The insoluble residue from the treatment is cellulose. + +The following oxycelluloses were investigated: + +A. _Product of action of nitric acid upon pine wood_ (Lindsey and +Tollens, Ann. 267, 366).--The oxycelluloses contained + +1 mol celloxin: {2 mol. cellulose on 6 hours' heating + {3 mol. cellulose on 3 hours' heating + +with a ratio H : O = 1 : 9 and 1 : 8.7 respectively: they yielded 7 +p.ct. furfural. + +B. _By action of bromine in presence of water and_ CaCO_{3} _upon +cotton_.--Yield, (air-dry) 85 p.ct. Empirical composition +C_{12}H_{20}O_{11} = C_{6}H_{10}O_{5}.C_{6}H_{10}O_{6}: yielded furfural +1.7 p.ct. + +C. _Cotton and nitric acid at_ 100°, two and a half hours (Cross and +Bevan).--Yield, 70 p.ct. Composition + + 4 C_{6}H_{10}O_{5}.C_{6}H_{8}O_{6} + +yielded furfural 2.3 p.ct. + +D. _Cotton and nitric acid at_ 100° (four hours).--A more highly +oxidised product resulted, viz. 3 C_{6}H_{10}O_{5}.C_{6}H_{8}O_{6}: +yielded furfural 3.2 p.ct. + +_By-products of oxidation._--The liquors from B were found to contain +saccharic acid: the acid from C and B contained a dibasic acid which +appeared to be tartaric acid. + +The isolation of (1) isosaccharinic and (2) dioxybutyric acid from the +products of digestion of the oxycelluloses with lime-milk at 100° was +effected by the separation of their respective calcium salts, (1) by +direct crystallisation, (2) by precipitation alcohol after separation of +the former. + + +CELLULOSES, HYDRO- AND OXYCELLULOSES, AND CELLULOSE ESTERS. + +L. VIGNON (Bull. Soc. Chim., 1901 [3], 25, 130). + +(a) _Oxycelluloses from cotton, hemp, flax, and ramie._--The +comparative oxidation of these celluloses, by treatment with HClO_{3} +at 100°, gave remarkably uniform results, as shown by the following +numbers, showing extreme variations: yields, 68-70 p.ct.; hydrazine +reaction, N fixed 1.58-1.69; fixation of basic colouring matters +(relative numbers), saffranine, 100-200, methylene blue, 100-106. The +only points of difference noted were (1) hemp is somewhat more resistant +to the acid oxidation; (2) the cotton oxycellulose shows a somewhat +higher (25 p.ct.) cupric reduction. + +(b) _'Saccharification' of cellulose, cellulose hydrates, and +hydrocellulose._--The products were digested with dilute hydrochloric +acid six hours at 100°, and the cupric reduction of the soluble products +determined and calculated to dextrose. + + 100 grms. of gave reducing products equal to Dextrose + +Purified cotton 3.29 + " Hydrocellulose 9.70 +Cotton mercerised (NaOH 30° B.) 4.39 +Cotton mercerised (NaOH 40° B.) 3.51 +Cellulose reprecipitated from cuprammonium 4.39 +Oxycellulose 14.70 +Starch 98.6 + +These numbers show that cellulose may be hydrated both by mercerisation +and solution, without affecting the constitutional relationships of the +CO groups. The results also differentiate the cellulose series from +starch in regard to hydrolysis. + +(c) _Cellulose and oxycellulose nitrates._--The nitric esters of +cellulose have a strong reducting action on alkaline copper solutions. +The author has studied this reaction quantitatively for the esters both +of cellulose and oxycellulose, at two stages of 'nitration,' represented +by 8.2-8.6 p.ct. and 13.5-13.9 p.ct. total nitrogen in the +ester-products, respectively. The results are expressed in terms (c.c.) +of the cupric reagent (Pasteur) reduced per 100 grs. compared with +dextrose (=17767). + + Cellulose maximum nitration (13.5 p.ct. N) 3640 + Oxycellulose maximum nitration (13.9 p.ct. N) 3600 + Cellulose minimum nitration (8.19 p.ct. N) 3700 + Oxycellulose minimum nitration (8.56 p.ct. N) 3620 + +The author concludes that, since the reducing action is independent of +the degree of nitration, and is the same for cellulose and the +oxycelluloses, the ester reaction in the case of the normal cellulose is +accompanied by oxidation, the product being an oxycellulose ester. + +_Products of 'denitration'._--The esters were treated with ferrous +chloride in boiling aqueous solution. The products were oxycelluloses, +with a cupric reduction equal to that of an oxycellulose directly +prepared by the action of HClO_{3}. On the other hand, by treatment with +ammonium sulphide at 35°-40° 'denitrated' products were obtained without +action on alkaline copper solutions. + + +OXYCELLULOSES AND THE MOLECULAR WEIGHT OF CELLULOSE. + +H. NASTUKOFF (Berl. Ber. 33 [13] 2237). + +(p. 61) The author continues his investigations of the oxidation of +cellulose. [Compare Bull. Mulhouse, 1892.] The products described were +obtained by the action of hypochlorites and permanganates upon Swedish +filter paper (Schleicher and Schüll). + +4. _Oxidation by hypochlorites._--(1) The cellulose was digested 24 hrs. +with 35 times its weight of a filtered solution of bleaching power of +4°B.; afterwards drained and exposed for 24 hrs. to the atmosphere. +These treatments were then repeated. After washing, treatment with +dilute acetic acid and again washing, the product was treated with a 10 +p.ct. NaOH solution. The oxycellulose was precipitated from the +filtered solution: yield 45 p.ct. The residue when purified amounted to +30 p.ct. of the original cellulose, with which it was identical in all +essential properties. + +The oxycellulose, after purification, dried at 110°, gave the following +analytical numbers: + + C 43.64 43.78 43.32 43.13 + H 6.17 6.21 5.98 6.08 + +Its compound with phenylhydrazine (_loc. cit._) gave the following +analytical numbers: + + N 0.78 0.96 0.84 + +(2) The reagents were as in (1), but the conditions varied by passing a +stream of carbonic acid gas through the solution contained in a flask, +until Cl compounds ceased to be given off. The analysis of the purified +oxycellulose gave C 43.53, H 6.13. + +(3) The conditions were as in (2), but a much stronger hypochlorite +solution--viz. 12°B.--was employed. The yield of oxycellulose +precipitated from solution in soda lye (10 p.ct. NaOH) was 45 p.ct. +There was only a slight residue of unattacked cellulose. The analytical +numbers obtained were: + + Oxycellulose C 43.31 43.74 43.69 + " H 6.47 6.42 6.51 + ________________________ + + Phenylhydrazine compound N 0.62 0.81 + +B. _Oxidation by permanganate_ (KMnO_{4}). (1) The cellulose 16 grms. +was treated with 1100 c.c. of a 1 p.ct. solution of KMnO_{4} in +successive portions. The MnO_{2} was removed from time to time by +digesting the product with a dilute sulphuric acid (10 p.ct. +H_{2}SO_{4}). The oxycellulose was purified as before, yield 40 p.ct. +Analytical numbers: + + Oxycellulose C 42.12 42.9 + " H 6.20 6.11 + ________________________ + + Phenylhydrazine compound N 1.35 1.08 1.21 + +(2) The cellulose (16 grms.) was digested 14 days with 2500 c.c. of 1 +p.ct. KMnO_{4} solution. The purified oxycellulose was identical in all +respects with the above: yield 40 p.ct. C 42.66, H 6.19. + +(3) The cellulose (16 grms.) was heated in the water-bath with 1600 c.c. +of 15 p.ct. H_{2}SO_{4} to which were added 18 grms. KMnO_{4}. The yield +and composition of the oxycellulose was identical with the above. It +appears from these results that the oxidation with hypochlorites acids 1 +atom of O to 4-6 of the unit groups C_{6}H_{10}O_{5}; and the oxidation +with permanganate 2 atoms O per 4-6 units of C_{6}H_{10}O_{5}. The +molecular proportion of N in the phenylhydrazine residue combining is +fractional, representing 1 atom O, i.e. 1 CO group reacting per 4 +C_{36}H_{60}O_{31} and 6 C_{24}H_{49}O_{21} respectively, assuming the +reaction to be a hydrazone reaction. + +Further investigations of the oxycelluloses by treatment with (a) +sodium amalgam, (b) bromine (water), and (c) dilute nitric acid at +110°, led to no positive results. + +By treatment with alcoholic soda (NaOH) the products were resolved into +a soluble and insoluble portion, the properties of the latter being +those of a cellulose (hydrate). + +_Molecular weight of cellulose and oxycellulose._--The author endeavours +to arrive at numbers expressing these relations by converting the +substances into acetates by Schutzenberger's method, and observing the +boiling-points of their solution in nitrobenzene. + + +FERMENTATION OF CELLULOSE + +V. OMELIANSKI (Compt. Rend., 1897, 125, 1131-1133). + +Pure paper was allowed to ferment in the presence of calcium carbonate +at a temperature of 35° for 13 months. The products obtained from +3.4743 grams of paper were: acids of the acetic series, 2.2402 grams; +carbonic anhydride, 0.9722 grams; and hydrogen, 0.0138 gram. The acids +were chiefly acetic and butyric acid, the ratio of the former to the +latter being 1.7 : 1. Small quantities of valeric acid, higher alcohols, +and odorous products were formed. + +The absence of methane from the products of fermentation is remarkable, +but the formation of this gas seems to be due to a special organism +readily distinguishable from the ferment that produces the fatty acids. +This organism is at present under investigation. + + * * * * * + +(p. 75) ~Constitution of Cellulose.~--It may be fairly premised that the +problem of the constitution of cellulose cannot be solved independently +of that of molecular aggregation. We find in effect that the structural +properties of cellulose and its derivatives are directly connected with +their constitution. So far we have only a superficial perception of this +correlation. We know that a fibrous cellulose treated with acids or +alkalis in such a way that only hydrolytic changes can take place is +converted into a variety of forms of very different structural +characteristics, and these products, while still preserving the main +chemical characteristics of the original, show when converted into +derivatives by simple synthesis, _e.g._ esters and sulphocarbonates, a +corresponding differentiation of the physical properties of these +derivatives, from the normal standard, and therefore that the new +reacting unit determines a new physical aggregate. Thus the +sulphocarbonate of a 'hydrocellulose' is formed with lower proportions +of alkaline hydrate and carbon disulphide, gives solutions of relatively +low viscosity, and, when decomposed to give a film or thread of the +regenerated cellulose, these are found to be deficient in strength and +elasticity. Similarly with the acetate. The normal acetate gives +solutions of high viscosity, films of considerable tenacity, and when +those are saponified the cellulose is regenerated as an unbroken film. +The acetates of hydrolysed celluloses manifest a retrogradation in +structural and physical properties, proportioned to the degree of +hydrolysis of the original. + +We may take this opportunity of pointing out that the celluloses not +only suggest with some definiteness the connection of the structural +properties of visible aggregates--that is, of matter in the mass--with +the configuration of the chemical molecule or reacting unit, but supply +unique material for the actual experimental investigation of the +problems involved. Of all the 'organic' colloids cellulose is the only +one which can be converted into a variety of derivative forms, from each +of which a regular solid can be produced in continuous length and of any +prescribed dimensions. Thus we can compare the structural properties of +cellulose with those of its hydrates, nitrates, acetates, and benzoates, +in terms of measurements of breaking strain, extensibility, elasticity. +Investigations in this field are being prosecuted, but the results are +not as yet sufficiently elaborated for reduction to formulæ. One +striking general conclusion is, however, established, and that is that +the structural properties of cellulose are but little affected by +esterification and appear therefore to be a function of the special +arrangement of the carbon atoms, i.e. of the molecular constitution. +Also it is established that the molecular aggregate which constitutes a +cellulose is of a resistant type, and undoubtedly persists in the +solutions of the compounds. + +It may be urged that it is superfluous to import these questions of +mass-aggregation into the problem of the chemical constitution of +cellulose. But we shall find that the point again arises in attempting +to define the reacting unit, which is another term for the molecule. In +the majority of cases we rely for this upon physical measurements; and +in fact the purely chemical determination of such quantities is +inferential. Attempts have been made to determine the molecular weights +of the cellulose esters in solution, by observations of depression of +solidifying and boiling-points. But the numbers have little value. The +only other well-defined compound is the sulphocarbonate. It has been +pointed out that, by successive precipitations of this compound, there +occurs a continual aggregation of the cellulose with dissociation of the +alkali and CS residues and it has been found impossible to assign a +limit to the dissociation, i.e. to fix a point at which the transition +from soluble sulphocarbonate to insoluble cellulose takes place. + +On these grounds it will be seen we are reduced to a somewhat +speculative treatment of the hypothetical ultimate unit group, which is +taken as of C_{6} dimensions. + +As there has been no addition of experimental facts directly +contributing to the solution of the problem, the material available for +a discussion of the probabilities remains very much as stated in the +first edition, pp. 75-77. It is now generally admitted that the +tetracetate _n_ [C_{6}H_{6}O.(OAc)_{4}] is a normal cellulose ester; +therefore that four of the five O atoms are hydroxylic. The fifth is +undoubtedly carbonyl oxygen. The reactions of cellulose certainly +indicate that the CO- group is ketonic rather than aldehydic. Even when +attacked by strong sulphuric acid the resolution proceeds some +considerable way before products are obtained reducing Fehling's +solution. This is not easily reconcilable with any polyaldose formula. +Nor is the resistance of cellulose to very severe alkaline treatments. +The probability may be noted here that under the action of the alkaline +hydrates there occurs a change of configuration. Lobry de Bruyn's +researches on the change of position of the typical CO- group of the +simple hexoses, in presence of alkalis, point very definitely in this +direction. It is probable that in the formation of alkali cellulose +there is a constitutional change of the cellulose, which may in effect +be due to a migration of a CO- position within the unit group. Again +also we have the interesting fact that structural changes accompany the +chemical reaction. It is surprising that there should have been no +investigation of these changes of external form and structure, otherwise +than as mass effects. We cannot, therefore, say what may be the +molecular interpretation of these effects. It has not yet been +determined whether there are any intrinsic volume changes in the +cellulose substance itself: and as regards what changes are determined +in the reacting unit or molecule, we can only note a fruitful subject +for future investigation. _A priori_ our views of the probable changes +depend upon the assumed constitution of the unit group. If of the +ordinary carbohydrate type, formulated with an open chain, there is +little to surmise beyond the change of position of a CO- group. But +alternative formulæ have been proposed. Thus the tetracetate is a +derivative to be reckoned with in the problem. It is formed under +conditions which preclude constitutional changes within the unit groups. +The temperature of the main reaction is 30°-40°, the reagents are used +but little in excess of the quantitative proportions, and the yields are +approximately quantitative. If now the derivative is formed entirely +without the hydrolysis the empirical formula C_{6}H_{6}O.(OAc)_{4} +justifies a closed-ring formula for the original viz. +CO<[CHOH]_{4}>CH_{2}; and the preference for this formula depends upon +the explanation it affords of the aggregation of the groups by way of +CO-CH_{2} synthesis. + +The exact relationship of the tetracetate to the original cellulose is +somewhat difficult to determine. The starting-point is a cellulose +hydrate, since it is the product obtained by decomposition of the +sulphocarbonate. The degree of _hydrolysis_ attending the cycle of +reactions is indicated by the formula 4 C_{6}H_{10}O_{5}.H_{2}O. It has +been already shown that this degree of hydrolysis does not produce +molecular disaggregation. If this hydrate survived the acetylation it +would of course affect the empirical composition, i.e. chiefly the +carbon percentage, of the product. It may be here pointed out that the +extreme variation of the carbon in this group of carbohydrate esters is +as between C_{14}H_{20}O_{10} (C = 48.3 p.ct.) and C_{14}H_{18}O_{9} (C += 50.8 p.ct.) i.e. a tetracetate of C_{6}H_{12}O_{6} and +C_{6}H_{10}O_{5} respectively. In the fractional intermediate terms it +is clear that we come within the range of ordinary experimental errors, +and to solve this critical point by way of ultimate analysis must +involve an extended series of analyses with precautions for specially +minimising and quantifying the error. The determination of the acetyl by +saponification is also subject to an error sufficiently large to +preclude the results being applied to solve the point. While, therefore, +we must defer the final statement as to whether the tetracetate is +produced from or contains a partly hydrolysed cellulose molecule, it is +clear that at least a large proportion of the unit groups must be +acetylated in the proportion C_{6}H_{6}O.(OAc)_{4}. + +It has been shown that by the method of Franchimont a higher proportion +of acetyl groups can be introduced; but this result involves a +destructive hydrolysis of the cellulose: the acetates are not +derivatives of cellulose, but of products of hydrolytic decomposition. + +It appears, therefore, that with the normal limit of acetylation at the +tetracetate the aggregation of the unit groups must depend upon the CO- +groups and a ring formula of the general form CO<[CHOH]_{4}>CH_{2} is +consistent with the facts. + +Vignon has proposed for cellulose the constitutional formula + + O------CH + | | \ + | O \[CHOH]_{3} + | | / + CH_{2}-CH/ + +with reference to the highest nitrate, and the decomposition of the +nitrate by alkalis with formation of hydroxypyruvic acid. While these +reactions afford no very sure ground for deductions as to constitutional +relationships, it certainly appears that, if the aldose view of the unit +group is to be retained, this form of the anhydride contains suggestions +of the general tendency of the celluloses on treatment with condensing +acids to split off formic acid in relatively large quantity [Ber. 1895, +1940]; the condensation of the oxycelluloses to furfural; the +non-formation of the normal hydroxy-dicarboxylic acids by nitric acid +oxidations. Indirectly we may point out that any hypothesis which +retains the polyaldose view of cellulose, and so fails to differentiate +its constitution from that of starch, has little promise of progress. +The above formula, moreover, concerns the assumed unit group, with no +suggestion as to the mode of aggregation in the cellulose complex. Also +there is no suggestion as to how far the formula is applicable to the +celluloses considered as a group. In extending this view to the +oxycelluloses, Vignon introduces the derived oxidised group + + CHO.(CHOH)_{3}.CH . CO + |_O__| + +--of which one is apportioned to three or four groups of the cellulose +previously formulated: these groups in condensed union together +constitute an oxycellulose. + +These views are in agreement with the experimental results obtained by +Faber and Tollens (p. 71). They regard the oxycelluloses as compounds of +'celloxin' C_{6}H_8{O}_{6} with 1-4 mols. unaltered cellulose; and the +former they particularly refer to as a lactone of glycuronic acid. But +on boiling with lime they obtain dioxybutyric and isosaccharinic acids; +both of which are not very obviously related to the compounds formulated +by Vignon. We revert with preference to a definitely ketonic formula, +for which, moreover, some farther grounds remain to be mentioned. In the +systematic investigation of the nitric esters of the carbohydrates (p. +41) Will and Lenze have definitely differentiated the ketoses from the +aldoses, as showing an internal condensation accompanying the ester +reaction. Not only are the OH groups taking part in the latter +consequently less by two than in the corresponding aldoses, but the +nitrates show a much increased stability. This would give a simple +explanation of the well-known facts obtaining in the corresponding +esters of the normal cellulose. We may note here that an important item +in the quantitative factors of the cellulose nitric ester reaction has +been overlooked: that is, the yield calculated to the NO_{3} groups +fixed. The theoretical yields for the higher nitrates are + + Yield p.ct. N p.ct. + of cellulose of nitrate + Pentanitrate 169 12.7 + Hexanitrate 183 14.1 + +From such statistics as are recorded the yields are not in accordance +with the above. There is a sensible deficiency. Thus Will and Lenze +record a yield of 170 p.ct. for a product with 13.8 p.ct. N, indicating +a deficiency of about 10 p.ct. As the by-products soluble in the acid +mixture are extremely small, the deficiency represents approximately the +water split off by an internal reaction. In this important point the +celluloses behave as ketoses. + +In the lignocelluloses the condensed constituents of the complex are of +well-marked ketonic, i.e. quinonic, type. In 'nitrating' the +lignocelluloses this phenomenon of internal condensation is much more +pronounced (see p. 131). As the reaction is mainly confined to the +cellulose of the fibre, we have this additional evidence that the +typical carbonyl is of ketonic function. It is still an open question +whether the cellulose constituents of the lignocelluloses are +progressively condensed--with progress of 'lignification'--to the +unsaturated or lignone groups. There is much in favour of this view, +the evidence being dealt with in the first edition, p. 180. The +transition from a cellulose-ketone to the lignone-ketone involves a +simple condensation without rearrangement; from which we may argue back +to the greater probability of the ketonic structure of the cellulose. We +must note, however, that the celluloses of the lignocelluloses are +obtained as residues of various reactions, and are not homogeneous. They +yield on boiling with condensing acids from 6 to 9 p.ct. furfural. It is +usual to regard furfural as invariably produced from a pentose residue. +But this interpretation ignores a number of other probable sources of +the aldehyde. It must be particularly remembered that lævulose is +readily condensed (a) to a methylhydroxyfurfural + +C_{6}H_{1}O_{6} - 3H_{2}O = C_{6}H_{6}O_{3} = C_{5}(OH).H_{2}.(CH_{3})O_{2} + +and (b) by HBr, with further loss of OH, as under: + +C_{6}H_{12}O_{6} - 4H_{2}O + HBr = C_{5}H_{3}(CH_{2}Br)O + +and generally the ketoses are distinguished from the aldoses by their +susceptibility to condensation. Such condensation of lævulose has been +effected by two methods: (a) by heating the concentrated aqueous +solution with a small proportion of oxalic acid at 3 atm. pressure +[Kiermayer, Chem. Ztg. 19, 100]; (b) by the action of hydrobromic acid +(gas) in presence of anhydrous ether; the actual compound obtained being +the omega-brommethyl derivative [Fenton, J. Chem. Soc. 1899, 423]. + +This latter method is being extended to the investigation of typical +celluloses, and the results appear to confirm the view that cellulose +may be of ketonic constitution. + +The evidence which is obtainable from the synthetical side of the +question rests of course mainly upon the physiological basis. There are +two points which may be noted. Since the researches of Brown and Morris +(J. Chem. Soc. 1893, 604) have altered our views of the relationships of +starch and cane sugar to the assimilation process, and have placed the +latter in the position of a primary product with starch as a species of +overflow and reserve product, it appears that lævulose must play an +important part in the elaboration of cellulose. Moreover, A. J. Brown, +in studying the cellulosic cell-collecting envelope produced by the +_Bacterium xylinum_, found that the proportion of this product to the +carbohydrate disappearing under the action of the ferment was highest in +the case of lævulose. These facts being also taken into consideration +there is a concurrence of suggestion that the typical CO group in the +celluloses is of ketonic character. That the typical cotton cellulose +breaks down finally under the action of sulphuric acid to dextrose +cannot be held to prove the aldehydic position of the carbonyls in the +unit groups of the actual cellulose molecule or aggregate. + +We again are confronted with the problem of the aggregate and as to how +far it may affect the constitution of the unit groups. That it modifies +the functions or reactivity of the ultimate constituent groups we have +seen from the study of the esters. Thus with the direct ester reactions +the normal fibrous cellulose (C_{6}H_{16}O_{5}) yields a monoacetate, +dibenzoate, and a trinitrate respectively under conditions which +determine, with the simple hexoses and anhydrides, the maximum +esterification, i.e. all the OH groups reacting. If the OH groups are of +variable function, we should expect the CO groups _a fortiori_ to be +susceptible of change of function, i.e. of position within the unit +groups. + +But as to how far this is a problem of the constitution or phases of +constitution of the unit groups or of the aggregate under reaction we +have as yet no grounds to determine. + +The subjoined communication, appearing after the completion of the MS. +of the book, and belonging to a date subsequent to the period intended +to be covered, is nevertheless included by reason of its exceptional +importance and special bearing on the constitutional problem above +discussed. + + +~THE ACTION OF HYDROGEN BROMINE ON CARBOHYDRATES.~[4] + +H. J. H. FENTON and MILDRED GOSTLING (J. Chem. Soc., 1901, 361). + +The authors have shown in a previous communication (Trans., 1898, 73, +554) that certain classes of carbohydrates when acted upon at the +ordinary temperature with dry hydrogen bromide in ethereal solution give +an intense and beautiful purple colour.[5] It was further shown (Trans., +1899, 75, 423) that this purple substance, when neutralised with sodium +carbonate and extracted with ether, yields golden-yellow prisms of +omega-brommethylfurfural, + + CH:C.CH_{2}Br + | | + | O + | | + CH:C.CHO. + +This reaction is produced by lævulose, sorbose, cane sugar, and inulin, +an intense colour being given within an hour or two. Dextrose, maltose, +milk sugar, galactose, and the polyhydric alcohols give, if anything, +only insignificant colours, and these only after long standing. The +authors therefore suggested that the reaction might be employed as a +means of distinguishing these classes of carbohydrates, the rapid +production of the purple colour being indicative of _ketohexoses_, or of +substances which produce these by hydrolysis. + +By relying only on the production of the purple colour, however, a +mistake might possibly arise, owing to the fact that _xylose_ gives a +somewhat similar colour after standing for a few hours. Hence, the +observations should be confirmed by isolation of the crystals of +brommethylfurfural. No trace of this substance is obtained from the +xylose product. + +In order to identify the substance, the ether extract, after +neutralisation, is allowed to evaporate to a syrup, and crystallisation +promoted either by rubbing with a glass rod, or by the more certain and +highly characteristic method of 'sowing' with the most minute trace of +omega-brommethylfurfural, when crystals are almost instantly formed. +These are recrystallised from ether, or a mixture of ether and light +petroleum, and further identified by the melting-point (59.5-60.5°), +and, if considered desirable, by estimation of the bromine. + +It is now found, so reactive is the bromine atom in this compound, that +the estimation may be accurately made by titration with silver nitrate +according to Volhard's process, the crystals for this purpose being +dissolved in dilute alcohol: + +0.1970 gram required 10.5 c.c. _N_/10 AgNO_{3}. Br = 42.63 +p.ct., calculated 42.32 p.ct. + +This method of applying hydrogen bromide in ethereal solution is, of +course, unsuitable for investigations where a higher temperature has to +be employed, or where long standing is necessary, since, under such +circumstances, the ether itself is attacked. Wishing to make +investigations under these conditions, the authors have tried several +solvents, and, at present, find that chloroform is best suited to the +purpose. In each of the following experiments, 10 grms. of the +substance were covered with 250 c.c. of chloroform which had been +saturated at 0° with dry hydrogen bromide. The mixture was contained in +an accurately stoppered bottle, firmly secured with an iron clamp, and +heated in a water-bath to about the boiling temperature for two hours. +After standing for several hours, the mixture was treated with sodium +carbonate (first anhydrous solid, and afterwards a few drops of strong +solution), filtered, and the solution dried over calcium chloride. Most +of the chloroform was then distilled off, and the remaining solution +allowed to evaporate to a thick syrup in a weighed dish. + +The product was then tested for omega-brommethylfurfural by 'sowing' +with the most minute trace of the substance, as described above. It was +then warmed on a water-oven, kept in a vacuum desiccator over solid +paraffin, and the weight estimated. When necessary, the product was +recrystallised from ether, and further identified by the tests +mentioned. The following results were obtained: + + Weight of + crude residue. +Swedish filter paper 3.0 crystallised at once by 'sowing.' +Ordinary cotton 3.3 " " +Mercerised cotton 2.1 " " +Straw cellulose[6] 2.3 " " +Lævulose 2.2 " " +Inulin 1.3 " " +Potato starch 0.37 " " +Cane sugar 0.85 " " +Dextrose 0.33 uncrystallisable. +Milk sugar 0.37 " +Glycogen 0.34 " +Galactose 0.34 " + +The products from _dextrose_, _milk sugar_, and _galactose_ absolutely +refused to crystallise even when extracted with ether and again +evaporated, or by 'sowing,' stirring, &c. + +The _glycogen_ product deposited a very small amount of crystalline +matter on standing, but the quantity was too minute for examination; +moreover, it refused altogether to crystallise in contact with the +aldehyde. It may fairly be stated, therefore, that these last four +substances give absolutely negative results as regards the formation of +omega-brommethylfurfural; if any is formed, its quantity is altogether +too small to be detected. + +The specimen of _starch_ examined was freshly prepared from potato, and +purified by digestion for twenty-four hours each with _N_/10 KOH, _N_/4 +HCl, and strong alcohol; it was then washed with water and allowed to +dry in the air. It will be seen that this substance gave a positive +result, but that the yield was extremely small, and might yet be due to +impurity. Considering the importance of the behaviour of starch, for the +purpose of drawing general conclusions from these observations, it was +thought advisable to make further experiments with specimens which could +be relied upon, and also to investigate the behaviour of dextrin. This +the authors have been enabled to do upon a series of specimens specially +prepared by C. O'Sullivan, and thus described by him: + + 1. Rice starch, specially purified by the permanganate method. + + 2. Wheat starch " " " + + 3. Oat starch, contains traces of oil, washed with dilute KOH + and dilute HCl. + + 4. Pea starch, first crop, washed with alkali, acid (HCl), and + strong alcohol. + + 5. Natural dextrin, D = 3.87, alpha_{D} = 194.7; K = 0.95, (c + 2.628). + + 6. alpha-Dextrin, C equation purified without fermentation, 30 + precipitations with alcohol (Trans., 1879, 35, 772). + +The examination of these specimens was conducted on a smaller scale, but +under the same conditions as before, _one gram_ of the substance being +treated with 12.5 c.c. of the saturated chloroform solution and heated +in sealed tubes for two hours as above. The results were as follows: + + Weight of + crude residue. +1. Rice starch 0.046 crystallised at once by 'sowing.' +2. Wheat starch 0.044 " " +3. Oat starch 0.049 " " +4. Pea starch 0.064 " " +5. Natural dextrin 0.088 " " +6. alpha-Dextrin 0.055 " " + +The results may therefore be summarised as follows:--Treated under these +particular conditions all forms of cellulose give large yields of +omega-brommethylfurfural, some varieties giving as much as 33 per cent. +Lævulose, inulin, and cane sugar give yields varying from 22 to 8.5 per +cent.; various starches give small yields (average about 4.5 per cent.); +and dextrins 5 to 8 per cent., whereas dextrose, milk sugar, and +galactose give, apparently, none at all. + +The yields represent the solid crystalline residue; this when purified +by recrystallisation gives, probably, about three-quarters of its weight +of pure crystals. (In the case of dextrose, &c., the yields represent +the weight of syrup.) + +These numbers, however, by no means represent the maximum yields +obtainable, owing to the comparatively slight solubility of hydrogen +bromide in chloroform. The process was conducted in the above manner +only for the sake of uniform comparison. The ether method previously +described gives much larger yields; for example, 12 grms. of inulin +treated with only 60 c.c. of the saturated ether gave 2.5 grms. of +substance. For the purpose of obtaining larger yields, other methods are +being investigated. + +The facts recorded above, taken in conjunction with those given in our +previous communications, appear to point definitely to the following +general conclusions. First, that the various forms of _cellulose_ +contain one or more groups or nuclei identical with that contained in +_lævulose_, and that such groups constitute the main or essential part +of the molecule. Secondly, that similar groupings are contained in +_starches_ and _dextrins_, but that the proportion of such groupings +represents a relatively small part of the whole structure. + +The nature of this grouping is, according to the generally accepted +constitution of _lævulose_, the six-carbon chain with a ketonic group: + + C·C·C·C·C·C + || . + O + +But the results might, on the other hand, be considered indicative of +the anhydride or 'lacton' grouping, which Tollens suggested for +lævulose: + + C·C·C·C·C·C + \ / + \ / . + O + +The latter very simply represents the formation of +omega-brommethylfurfural from lævulose,[7] + + ------O----- + | H H | + | | | | + OH·C-----C---C---C--C-----CH_{2}·OH + H_{2} OH OH OH H + +giving + + H H + HC·C:C·C:C·CH_{2}Br + || \ / , + O \ / + O + + +although by a little further 'manipulation' of the symbols the change +could, of course, be represented by reference to the ketonic formula. + + +~The Ketonic Constitution of Cellulose.~ + +C. F. CROSS and E. J. BEVAN (J. Chem. Soc., 1901, 366). + +In this paper the authors discuss more fully the theoretical bearings of +the observations of Fenton and Gostling, the two papers being +simultaneously communicated. The paper is mainly devoted to a review of +the antecedent evidence, chemical and physiological, and to a general +summing up in favour of the view that cellulose is a polyketose +(anhydride). + + * * * * * + +(p. 79) ~Composition of the Seed Hair of Eriodendron~ (~Anf.~)--Some +interest attaches to the results of an analytical investigation which we +have made of this silky floss. There is little doubt that cotton is +entirely exceptional in its characteristics: both in structure and +chemical composition it fails to show any adaptation to what we may +regard as the _more obvious_ functions of a seed hair--which certainly +do not demand either structural strength or chemical resistance. The +following numbers determined for the kapok differentiate it widely from +the cottons: + + Ash, 1.3; moisture, 9.3; alkaline hydrolysis (loss) (a) 16.7, + (b) 21.8. Cellulose, by chlorination, &c., 71.1. + +In reacting with chloride it shows the presence of unsaturated groups, +similar to the lignone of the woods. This was confirmed by a +well-marked reaction with ferric ferricyanide with increase of weight +due to the fixation of the blue cyanide. + +But the most characteristic feature is the high yield of furfural on +boiling with condensing acids. The following numbers were determined: + + Total furfural from original fibre 14.84 + In residue from alkali hydrolysis 11.5 + In cellulose isolated by Cl method 10.4 + +Treated with sulphuric acids of concentration, (a) 92.1 grs. +H_{2}SO_{4} per 100 c.c., (b) 105.8 grs. per 100 c.c., the fibres +dissolve, and diluted immediately after complete solution it was +resolved into + + (a) (b) + +Reprecipitated fraction 68.7 43.7 +Soluble fraction yielding furfural 13.2 14.3 + +By these observations it is established that the furfuroids are of the +cellulose type and behave very much as the furfuroids of the cereal +celluloses. + +This group of seed hairs invites exhaustive investigation. The furfuroid +constituents are easily isolated, and as they constitute at least +one-third of the fibre substance it is especially from this point of +view that they invite study. + + +RECHERCHES SUR L'OXYCELLULOSE. + +L. VIGNON. + +~Résumé of investigations (1898-1900) of Oxycellulose, published as a +brochure~ (Rey, Lyon, 1900). + +(a) A typical oxycellulose prepared from cotton cellulose by the +action of HClO_{3} (HCl + KClO_{3}) in dilute solution at 100° for one +hour gave the following numbers: + + C H O +Elementary composition 43.55 6.03 50.42 + + Oxycellulose Original cellulose + Analysis by Lange's method + Soluble in KOH (at 180°) 87.6 12.0 + Insoluble in KOH (at 180°) 12.4 88.0 + + Oxycellulose Original cellulose + Heat of combustion 4124-4133 4190-4224 +Heat evolved in contact with 50 times wt.} + normal KOH per 100 grms. } 1.3 cal. 0.74 cal. + + Oxycellulose Cellulose +Absorption of colouring } Saffranine 0.7 0.0 +matters at 100° per 100 grms. } Methylene blue 0.6 0.2 + +(b) _Yield of furfural from cellulose, oxy- and +hydro-cellulose._--From the hydrocelluloses variously prepared the +author obtains 0.8 p.ct. furfural; from bleached cotton 1.8 p.ct.; and +from the oxycelluloses variously prepared 2.0-3.5 p.ct. The 'furfuroid' +is relatively more soluble in alkaline solutions (KOH) in the cold. The +insoluble residue is a normal cellulose. + +(c) _Nitrates of cellulose, oxy- and hydro-cellulose._--Treated with +the usual acid mixture (H_{2}SO_{4} 3 p., HNO_{3} 1 p.) under conditions +for maximum action, the resulting esters showed uniformly a fixation of +11.0 NO_{2} groups per unit mol. of C_{24}. The oxycellulose nitrate +was treated directly with dilute solution of potassium hydrate in the +cold. From the products of decomposition the author obtained the osazone +of hydroxypyruvic acid [Will, Ber. 24, 400]. + +(d) _Osazones of the oxycelluloses._--Oxycelluloses prepared by +various methods are found to fix varying proportions of phenylhydrazine +(residue), viz. from 3.4-8.5 p.ct. of the cellulose derivative reacting, +corresponding with, i.e. calculated from, the nitrogen determined in the +products (0.87-2.2 p.ct.). The reaction is assumed to be that of osazone +formation. + +The author has also established a relation between the phenylhydrazine +fixed and the furfural which the substance yields on boiling with +condensing acids. This is illustrated by the subjoined series of +numbers: + + Phenylhydrazine Furfural + Fixed p.ct. formed p.ct. +Cotton (bleached) 1.73 1.60 +Oxycellulose (HClO_{3}) 7.94 2.09 + " (HClO) 3.37 1.79 + " (CrO_{3}) (1) 7.03 3.00 + " (CrO_{3}) (2) 7.71 3.09 + " (CrO_{3}) (3) 8.48 3.50 + +(e) _Constitution of cellulose and oxycellulose._--The results of +these investigations are generalised as regards cellulose (C_6) by the +constitutional formula + + CH--CH_{2} + / | | + (CHOH)_{3} O | + \ | | + CH--O . + +The oxycelluloses contain the characteristic group + + COH + / + (CHOH)_{3} + \ + CH--CO + \ / + O + +in union with varying proportions of residual cellulose. + + +QUANTITATIVE SEPARATION OF CELLULOSE-LIKE CARBOHYDRATES IN VEGETABLE +SUBSTANCES. + +WILHELM HOFFMEISTER (Landw. Versuchs-Stat., 1897, 48, 401-411). + +To separate the hemicelluloses, celluloses, and the constituents of +lignin without essential change, the substance, after being freed from +fat, is extracted with dilute hydrochloric acid and ammonia, and the +residue frequently agitated for a day or two with 5-6 p.ct. caustic soda +solution. It is then diluted, the extract poured off, neutralised with +hydrochloric acid, treated with sufficient alcohol, and the +hemicellulose filtered, dried, and weighed. The residue from the soda +extract is washed on a filter with hot water, and extracted with +Schweizer's reagent. + +When the final residue (lignin) is subjected to prolonged extraction +with boiling dilute ammonia (a suitable apparatus is described, with +sketch) until the ammonia is no longer coloured, a residue is obtained +which mostly dissolves in Schweizer's reagent, and on repeating the +process the residue is found to consist largely of mineral matter. The +dissolved cellulose-like substances often contain considerable amounts +of pentosanes. + +According to the nature of the substance, the extraction with ammonia +may take weeks, or months, or even longer; the ammonia extracts of hard +woods (as lignum vitæ) and of cork are dark brown, and give an odour of +vanilla when evaporated down. The residues, which are insoluble in +water, but redissolve in ammonia, have the properties of humic acids. +Other vegetable substances, when extracted, yielded, besides humic +acids, a compound, C_{6}H_{7}O_{2}, soluble in alcohol and chloroform, +but insoluble in water, ether, and benzene; preparations from different +sources melted between 200° and 210°. + +FOOTNOTES: + +[4] The original paper is reproduced with slight alterations. + +[5] This purple colour would appear to be due to a highly dissociable +compound of omega-brommethylfurfural with hydrogen bromide. The aldehyde +gives yellow or colourless solutions in various solvents, which are +turned purple by a sufficient excess of hydrogen bromide. Dilution, or +addition of water, at once discharges the colour. + +[6] Other forms of cellulose were also examined--for example, pinewood +cellulose--and the substances separated from solution as thiocarbonate +(powder and film). All of these gave good yields of +omega-brommethylfurfural. + +[7] The change is empirically represented as + +C_{6}H_{12}O_{6} + HBr - 4H_{2}O = C_{6}H_{5}O_{2}Br. + + + + +SECTION IV. CELLULOSE GROUP, INCLUDING HEMICELLULOSES AND TISSUE +CONSTITUENTS OF FUNGI + + +VERSUCHE ZUR BESTIMMUNG DES GEHALTS EINIGER PFLANZEN UND PFLANZENTEILE +AN ZELLWANDBESTANDTEILEN AN HEMICELLULOSEN UND AN CELLULOSE. + +A. KLEIBER (Landw. Vers.-Stat., 1900, 54, 161). + +~ON THE DETERMINATION OF CELL-WALL CONSTITUENTS, HEMICELLULOSES AND +CELLULOSE IN PLANTS AND PLANT TISSUES.~ + +In a preliminary discussion the author critically compares the results +of various of the methods in practice for the isolation and estimation +of cellulose. The method of F. Schulze [digestion with dil. HNO_{3} with +KClO_{3}--14 days, and afterwards treating the product with ammonia, +&c.] is stated to be the 'best known' (presumably the most widely +practised); W. Hoffmeister's modification of the above, in which the +nitric acid is replaced by hydrochloric acid (10 p.ct. HCl) is next +noted as reducing the time of digestion from 14 days to 1-2 days, and +giving in many cases higher yields of cellulose. The methods of treating +with the halogens, viz. bromine water (H. Müller), chlorine gas (Cross +and Bevan), and chlorine water, are dismissed with a bare mention, +apparently on the basis of the conclusions of Suringar and Tollens +(_q.v._). The method of Lange, the basis of which is a 'fusion' with +alkaline hydrates at 180°, and the modified method of Gabriel, in which +the 'fusion' with alkali takes place in presence of glycerin, are +favourably mentioned. + +These methods were applied to a range of widely different raw materials +to determine, by critical examination of the products, both as regards +yield and composition, what title these latter have to be regarded as +'pure cellulose.' + +This portion of the investigation is an extension of that of Suringar +and Tollens, these latter confining themselves to celluloses of the +'normal' groups, i.e. textile and paper-making celluloses. The present +communication is a study of the tissue and cell-wall constituents of the +following types:-- + + 1. Green plants of false oat grass (_Arrhenatherium, E._). + 2. Green plants of lucerne (_Medicago sativa_). + 3. Leaves of the ash (_Fraxinus_). + 4. Leaves of the walnut (_Juglans_). + 5. Roots of the purple melic grass (_Molinia cærulea_). + 6. Roots of dandelion (_Taraxacum officinale_). + 7. Roots of comfrey. + 8. Coffee berries. + 9. Wheat bran. + +These raw materials were treated for the quantitative estimation of +cellulose by the method of Lange (b), Hoffmeister (c), and Schulze +(d), and the numbers obtained are referred for comparison to the +corresponding yields of 'crude fibre' (Rohfaser) by the standard method +(a). + +As a first result the author dismisses Lange's method as hopeless: the +results in successive determinations on the same materials showing +variations up to 60 p.ct. The results by c and d are satisfactorily +concordant: the yields of cellulose are higher than of 'crude fibre.' +This is obviously due to the conservation of 'hemicellulose' products, +which are hydrolysed and dissolved in the treatments for 'crude fibre' +estimation. A modified method was next investigated, in which the +process of digestion with acid chloroxy- compounds (c and d) was +preceded by a treatment with boiling dilute acid. The yields of +cellulose by this method (e) are more uniform, and show less +divergence from the numbers for 'crude fibre.' + +The author's numerical results are given in a series of tables which +include determinations of proteids and ash constituents, and the +corresponding deductions from the crude weight in calculating to 'pure +cellulose.' The subjoined extract will illustrate these main lines of +investigation. + + ___________________________________________________________ +| | | | +| | Crude Fibre | Pure Cellulose | +| |_____________|____________________________| +| | | | | +| Raw Material | Weende | Hoffmeister | Hoffmeister, | +| | Method. | Method. | modified by | +| | (a) | (c) | Author. | +| | | | (e) | +|________________|_____________|_____________|______________| +| | | | | +| Oat grass | 30.35 | 34.9 | 31.5 | +| Lucerne | 25.25 | 28.7 | 20.5 | +| Leaves of ash | 13.05 | 15.4 | 13.8 | +| Roots of melic | 21.60 | 29.1 | 21.4 | +| Coffee beans | 18.30 | 35.1 | 23.3 | +| Bran | 8.2 | 19.3 | 9.3 | +|________________|_____________|_____________|______________| + +The final conclusion drawn from these results is that the method of +Hoffmeister yields a product containing variable proportions of +hemicelluloses. These are eliminated by boiling with a dilute acid (1.25 +p.ct. H_{2}SO_{4}), which treatment may be carried out on the raw +material--i.e. before exposure to the acid chlorate, or on the crude +cellulose as ordinarily isolated. + +~Determination of Tissue-constituents.~--By the regulated action of +certain solvents applied in succession, it appears that such +constituents of the plant-complex can be removed as have no organic +connection with the cellular skeleton: the residue from such treatments, +conversely, fairly represents the true tissue-constituents. The author +employs the method of digestion with cold dilute alkaline solutions +(0.15 to 0.5 p.ct. NaOH), followed by exhaustive washing with cold and +hot water, afterwards with cold and hot alcohol, and finally with ether. + +The residue is dried and weighed as crude product. When necessary, the +proportions of ash and proteid constituents are determined and deducted +from the 'crude product' which, thus corrected, may be taken as +representing the 'carbohydrate' tissue constituents. + +~Determination of Hemicelluloses.~--By the process of boiling with dilute +acids (1.25 p.ct. H_{2}SO_{4}) the hemicelluloses are attacked--i.e. +hydrolysed and dissolved. The action of the acid though selective is, of +course, not exclusively confined to these colloidal carbohydrates. The +proteid and mineral constituents are attacked more or less, and the +celluloses themselves are not entirely resistant to the action. The loss +due to the latter may be neglected, but in calculating the hemicellulose +constants from the gross loss the proteids and mineral constituents +require to be taken into account in the usual way. + + +QUANTITATIVE SEPARATION OF HEMICELLULOSE, CELLULOSE, AND LIGNIN. +PRESENCE OF PENTOSANES IN THESE SUBSTANCES. + +WILHELM HOFFMEISTER (Landw. Versuchs-Stat, 1898, 50, 347-362). + +(p. 88) The separation of the cellulose-like carbohydrates of sunflower +husks is described. + +In order to ascertain the effect of dilute ammonia on the cellulose +substances of lignin, a dried 5 p.ct. caustic soda extract was extracted +successively with 1, 2, 3, and 4 p.ct. sodium hydroxide solution. Five +grams of the 2 p.ct. extract were then subjected to the action of +ammonia vapour; the cellulose did not completely dissolve in six weeks. +Cellulose insoluble in caustic soda (32 grms.) was next extracted with +ammonia, in a similar manner, for 10 days, dried, and weighed. 30.46 +grms. remained, which, when treated with 5 p.ct. aqueous caustic soda, +yielded 0.96 grm. (3 per cent.) of hemicellulose. + +When cellulose is dissolved in Schweizer's solution, the residue is, by +repeated extraction with aqueous sodium hydroxide, completely converted +into the soluble form. On evaporating the ammonia from the Schweizer's +extract, at the ordinary temperature and on a water-bath respectively, +different amounts of cellulose are obtained; more hemicellulose is +obtained, by caustic soda, from the heated solution than from that which +was not heated. In this operation the pentosanes are more influenced +than the hexosanes; pentosanes are not always readily dissolved by +caustic soda, and hexosanes are frequently more or less readily +dissolved. Both occur in lignin, and are then undoubtedly indigestible. +These points have to be considered in judging the digestibility of these +carbohydrates. + +A comparison of analyses of clover, at different periods, in the first +and second years of growth, shows that both cellulose (Schweizer's +extract) and lignin increase in both constituents. In the second year +the lignin alone increased to the end; the cellulose decreased at the +end of June. In the first year it seemed an absolutely as well as +relatively greater amount of cellulose, and lignin was produced in the +second year; this, however, requires confirmation. The amount of +pentosanes in the Schweizer extract was relatively greater in the second +than in the first year, but decreased in the lignin more in the second +year than in the first: this result is also given with reserve. + + +DIE CONSTITUTION DER CELLULOSEN DER CEREALIEN. + +C. F. CROSS, E. J. BEVAN, and C. SMITH (Berl. Ber., 1896, 1457). + +~THE CONSTITUTION OF THE CEREAL CELLULOSES.~ + +(p. 84) Straw cellulose is resolved by two methods of acid hydrolysis +into a soluble furfural-yielding fraction, and an insoluble fraction +closely resembling the normal cellulose. (a) The cellulose is +dissolved in sulphuric acids of concentration, H_{2}SO_{4}.2H_{2}O, +H_{2}SO_{4}.3H_{2}O. As soon as solution is complete, the acid is +diluted. A precipitate of cellulose hydrate (60-70 p.ct.) is obtained, +and the filtered solution contains 90-95 p.ct. of the furfuroids of the +original cellulose. The process is difficult to control, however, in +mass, and to obtain the latter in larger quantity the cellulose (b) is +digested with six times its weight of 1 p.ct. H_{2}SO_{4} at 3 atm. +pressure, the products of the action being (1) a disintegrated cellulose +retaining only a small fraction (1/12) of the furfural-yielding groups, +and (2) a slightly coloured solution of the hydrolised furfuroids. An +investigation of the latter gave the following results: By oxidation +with nitric acid no saccharic acid was obtained; showing the absence of +dextrose. The numbers for cupric reduction were in excess of those +obtained with the hexoses. The yield of ozazone was high, viz. 30 to 40 +p.ct. of the weight of the carbohydrate in solution. On fractionating, +the melting-points of the fractions were found to lie between 146° and +153°. Ultimate analysis gave numbers for C, H, and N identical with +those of a pentosazone. The product of hydrolysis appears, therefore, to +be xylose or a closely related derivative. + +All attempts to obtain a crystallisation of xylose from the solution +neutralised (BaCO_{3}), filtered, and evaporated, failed. The reaction +with phloroglucol and HCl, moreover, was not the characteristic red of +the pentoses, but a deep violet. The product was then isolated as a dry +residue by evaporating further and drying at 105°. Elementary analysis +gave the numbers C 44.2, 44.5, and H 6.7, 6.3. Determinations of +furfural gave 39.5 to 42.5 p.ct. On treating the original solution with +hydrogen peroxide, and warming, oxidation set in, with evolution of +CO_{2}. This was estimated (by absorption), giving numbers for CO_{2}, +19.5, 20.5, 20.1 p.ct. of the substance. + +The sum of these quantitative data is inconsistent with a pentose or +pentosane formula; it is more satisfactorily expressed by the empirical +formula + + O + / \ + C_{5}H_{8}O_{3} CH_{2}, + \ / + O + +which represents a pentose monoformal. Attempts to synthesise a compound +of this formula have been so far without success. + + +UEBER EINIGE CHEMISCHE VORGÄNGE IN DER GERSTENPFLANZE. + +C. F. CROSS, E. J. BEVAN, and C. SMITH (Berl. Ber., 1895, 2604). + +~THE CHEMICAL LIFE-HISTORY OF THE BARLEY PLANT.~ + +(p. 84) Owing to the presence of 'furfuroids' in large proportion as +constituents of the tissues of the stems of cereals, these plants afford +convenient material for studying the problem of the constitution of the +tissue-furfuroids, as well as their relationship to the normal +celluloses. The growing barley plant was investigated at successive +periods of growth. Yield of furfural was estimated on the whole plant +and on the residue from a treatment with alkaline and acid solvents in +the cold such as to remove all cell contents. This residue is described +as 'permanent tissue.' The observations were carried out through two +growing seasons--1894-5--which were very different in character, the +former being rainy with low temperature, the latter being abnormal in +the opposite direction, i.e. minimum rainfall and maximum sunshine. The +barley selected for observation was that of two experimental plots of +the Royal Agricultural Society's farm, one (No. 1) remaining permanently +unmanured, and showing minimum yield, the other (No. 6) receiving such +fertilising treatment as to give maximum yields. + +The numerical results are given in the annexed tables: + +Table Headings: + +A: Date +B: Age of Crop +C: Plot +D: Dry Weight +E: Furfural p.ct. of dry weight (a) +F: Permanent tissue p.ct. dry weight +G: Furfural from permanent tissue +H: P.ct. of tissue +I: P.ct. of entire plant +J: Ratio a : c + +BARLEY CROP, WOBURN, 1894. + + ________________________________________________________________________ +| | | | | | | | | +| | | | | | | [G] | | +| | | | | | |_____________| | +| | | | | | | | | | +| [A] | [B] | [C] | [D] | [E] | [F] | [H] | [I] | [J] | +|_________|__________|_____|______|______|______|______|______|__________| +| | | | | | | | | | +| May 7 | 6 weeks | 1 | 19.4 | 7.0 | 53.4 | 12.7 | 6.8 | 1.03 : 1 | +| | | 6 | 14.7 | 7.0 | 55.9 | 10.3 | 5.7 | 1.23 : 1 | +| June 4 | 10 weeks | 1 | 17.6 | 7.7 | 52.9 | 11.6 | 6.1 | 1.26 : 1 | +| | | 6 | 13.5 | 8.1 | 58.5 | 13.4 | 7.8 | 1.04 : 1 | +| July 10 | 15 weeks | 1 | 42.0 | 9.0 | 65.7 | 9.8 | 6.4 | 1.40 : 1 | +| | | 6 | 32.9 | 10.6 | 65.7 | 12.5 | 8.2 | 1.30 : 1 | +| Cut | 21 weeks | 1 | 64.0 | 11.9 | 70.0 | 14.5 | 10.1 | 1.18 : 1 | +| Aug. 21 | | 6 | 64.6 | 13.4 | 70.5 | 15.0 | 10.6 | 1.26 : 1 | +| Carried | 22 weeks | 1 | 84.0 | 12.7 | 75.0 | 16.5 | 12.4 | 1.02 : 1 | +| Aug. 31 | | 6 | 86.4 | 12.4 | 78.4 | 15.1 | 11.8 | 1.05 : 1 | +| | +| BARLEY CROP, WOBURN, 1895. | +| | +| May 15 | 7 weeks | 1 | 20.6 | 6.6 | 53.9 | 10.2 | 5.5 | 1.20 : 1 | +| | | 6 | 17.8 | 5.8 | 56.7 | 9.6 | 5.4 | 1.07 : 1 | +| June 18 | 12 weeks | 1 | 34.6 | 8.0 | 38.2 | 14.7 | 5.6 | 1.42 : 1 | +| | | 6 | 33.4 | 7.6 | 44.5 | 15.0 | 6.7 | 1.14 : 1 | +| July 16 | 16 weeks | 1 | 52.8 | 12.1 | 55.6 | 16.3 | 9.1 | 1.33 : 1 | +| | | 6 | 54.4 | 10.6 | 46.2 | 19.1 | 8.8 | 1.20 : 1 | +| Aug. 16 | 20 weeks | 1 | 66.8 | 9.2 | 49.1 | 17.0 | 8.3 | 1.10 : 1 | +| | | 6 | 65.0 | 9.8 | 49.8 | 19.1 | 9.4 | 1.04 : 1 | +| Sept. 3 | 22 weeks | 1 | 84.3 | 10.4 | 45.7 | 17.6 | 8.0 | 1.31 : 1 | +| | | 6 | 86.3 | 10.2 | 45.3 | 17.3 | 7.8 | 1.30 : 1 | +|_________|__________|_____|______|______|______|______|______|__________| + +The variations exhibited by these numbers are significant. It is clear, +on the other hand, that the assimilation of the furfuroids does not vary +in any important way with variations in conditions of atmosphere and +soil nutrition. They are essentially _tissue_-constituents, and only at +the flowering period is there any accumulation of these compounds in the +alkali-soluble form. It has been previously shown (ibid. 27, 1061) +that the proportion of furfuroids in the straw-celluloses of the +paper-maker differs but little from that of the original straws. For the +isolation of the celluloses the straws are treated by a severe process +of alkaline hydrolysis, to which, therefore, the furfuroid groups offer +equal resistance with the normal hexose groups with which they are +associated in the complex. + +The furfuroids of the cereal straws are therefore not pentosanes. They +are original products of assimilation, and not subject to secondary +changes after elaboration such as to alter either their constitution or +their relationship to the normal hexose groups of the tissue-complex. + + +(1) CONSTITUTION OF THE CEREAL CELLULOSES + +(Chem. Soc. J. 1896, 804). + + +(2) THE CARBOHYDRATES OF BARLEY STRAW + +(Chem. Soc. J. 1896, 1604). + + +(3) THE CARBOHYDRATES OF THE CEREAL + +STRAWS (Chem. Soc. J. 1897, 1001). + + +(4) THE CARBOHYDRATES OF BARLEY STRAW + +(Chem. Soc. J. 1898, 459). + +C. F. CROSS, E. J. BEVAN, and CLAUD SMITH. + +These are a series of investigations mainly devoted to establishing the +identity of the furfural-yielding group which is a characteristic +constituent. + +This 'furfuroid' while equally resistant to alkalis as the normal +cellulose group with which it is associated, is selectively hydrolysed +by acids. Thus straw cellulose dissolves in sulphuric acids of +concentration H_{2}SO_{4}.2H_{2}O - H_{2}SO_{4}.3H_{2}O, and on diluting +the normal cellulose is precipitated as a hydrate, and the furfuroid +remains in solution. But this sharp separation is difficult to control +in mass. By heating with a very dilute acid (1 p.ct. H_{2}SO_{4}) the +conditions are more easily controlled, the most satisfactory results +being obtained with 15 mins. heating at 3 atm. pressure. + +(1) Operating in this way upon brewers' grains the furfuroid was +obtainable as the chief constituent of a solution for which the +following experimental numbers were determined:--Total dissolved solids, +28.0 p.ct. of original 'grains'; furfural, 39.5 p.ct. of total dissolved +solids, as compared with 12.5 p.ct. of total original grains; cupric +reduction (calc. to total solids), 110 (dextrose = 100) osazone; yield +in 3 p.ct. solution, 35 p.ct. of weight of total solids. + + Pentosazone + Analysis N 17.1 17.3 17.07 + C 62.5 62.3 62.2 + H 6.4 6.5 6.1 + Melting-point 146°-153° + +From these numbers it is seen that of the total furfuroids of the +original 'grains' 84 p.ct. are thus obtained in solution in the fully +hydrolysed form, which is that of a pentose or pentose derivative. It +was, however, found impossible to obtain any crystallisation from the +neutralised (BaCO_{3}) and concentrated solution, the syrup being kept +for some weeks in a desiccator. It was noted at the same time that the +colour reaction of the original solution with phloroglucol and +hydrochloric acid was a deep violet, in contradistinction to the +characteristic red of the pentoses. On oxidation with hydrogen peroxide, +in the proportion of 1 mol. H_{2}O_{2} to 1 mol. of the carbohydrate in +solution, carbonic anhydride was formed in quantity = 20.0 p.ct. of the +latter. + +Fermentation (yeast) experiments also showed a divergence from the +resistant behaviour of the pentoses, a considerable proportion of the +furfuroid disappearing in a normal fermentation. + +(2) The quantitative methods above described were employed in +investigating the barley plant at different stages of its growth. The +green plant was extracted with alcohol, the residue freed from alcohol +and subjected to acid hydrolysis. + +The hydrolysed extract was neutralised and fermented. In the early +stages of growth the furfuroids were completely fermented, i.e. +disappeared in the fermentation. In the later stages this proportion +fell to 50 p.ct. In the earlier stages, moreover, the normal hexose +constituents of the permanent tissue were hydrolysed in large proportion +by the acid, whereas in the matured straw the hydrolysis is chiefly +confined to the furfuroids. In the early stages also the permanent +tissue yields an extract with relatively low cupric reduction, showing +that the carbohydrates are dissolved by the acid in a more complex +molecular condition. + +These observations confirm the view that the furfuroids take origin in a +hexose-pentose series of transformations. The proportion of furfuroid +groups to total carbohydrates varies but little, viz. from 1/3 in the +early stages to a maximum of 1/4 at the flowering period. At this period +the differentiation of the groups begins to be marked. + +Taking all the facts of (1) and (2), they are not inconsistent with the +hypothesis of an internal transformation of a hexose to a +pentose-monoformal. Such a change of position and function of oxygen +from OH to CO within the group --CH.OH-- is a species of internal +oxidation which reverses the reduction of formaldehyde groups in +synthesising to sugars, and appears therefore of probable occurrence. + +These constitutional problems are followed up in (3) by the indirect +method of differentiating the relationships of these furfuroids to yeast +fermentation, from those of the pentoses. Straw and esparto celluloses +are subjected to the processes of acid hydrolysis, and the neutralised +extracts fermented. With high furfural numbers indicating that the +furfuroids are the chief constituents of the extract, there is an active +fermentation with production of alcohol. The cupric reduction falls in +greater ratio to the original (unfermented) than the furfural. +Observations on the pure pentoses--xylose and arabinose added to +dextrose solutions, and then exposed to yeast action--show that in a +vigorous fermentation not unduly prolonged the pentoses are unaffected, +but that they do come within the influence of the yeast-cell when the +latter is in a less vigorous condition, and when the hexoses are not +present in relatively large proportion. + +(4) The observations on the growing plant were resumed with the view of +artificially increasing the differentiation of the two main groups of +carbohydrates. From a portion of a barley crop the inflorescence was +removed as soon as it appeared. The crop was allowed to mature, and a +full comparison instituted between the products of normal and abnormal +growth. With a considerable difference in 'permanent tissue' (13 p.ct. +less) and a still greater defect in cellulose (24 p.ct.), the constants +for the furfuroids in relation to total carbohydrates were unaffected by +the arrested development. This was also true of the behaviour of the +hydrolysed extracts (acid processes) to yeast fermentation. + +(5) The extract obtained from the brewers' grains by the process +described in (2) was investigated in relation to animal digestion. It +has been now generally established that the furfuroids as constituents +of fodder plants are digested and assimilated in large proportion in +passing through animal digestive tracts, and in this respect behave +differently from the pentoses. The furfuroids being obtained, as +described, in a fully hydrolysed condition (monoses) the digestion +problem presented itself in a new aspect, and was therefore attacked. + +The result of the comparative feeding experiments upon rabbits was to +show that in this previously hydrolysed form the furfuroids are almost +entirely digested and assimilated, no pentoses, moreover, appearing in +the urine. + +Generally we may sum up the present solution of the problem of the +relationship of the furfuroids to plant assimilation and growth as +follows:--The pentoses are not produced as such in the process of +assimilation; but furfural-yielding carbohydrates are produced directly +and in approximately constant ratio to the total carbohydrates; they are +mainly located in the permanent tissue; in the secondary changes of +dehydration, &c., accompanying maturation they undergo such +differentiation that they become readily separable by processes of acid +hydrolysis from the more resistant normal celluloses; but in relation to +alkaline treatments they maintain their intimate union with the latter. +They are finally converted into pentoses by artificial treatments, and +into pentosanes in the plant, with loss of 1 C atom in an oxidised form. +The mechanism of this transformation of hexoses into pentoses is not +cleared up. It is independent of external conditions, e.g. +fertilisation and atmospheric oxidations, and is probably therefore a +process of internal rearrangement of the character of an oxidation. + + +ZUR KENNTNISS DER IN DEN MEMBRANEN DER PILZE ENTHALTENEN BESTANDTHEILE. + +E. WINTERSTEIN (Ztschr. Physiol. Chem., 1894, 521; 1895, 134). + +~ON THE CONSTITUENTS OF THE TISSUE OF FUNGI.~ + +(p. 87) These two communications are a contribution of fundamental +importance, and may be regarded as placing the question of the +composition of the celluloses of these lowest types on a basis of +well-defined fact. In the first place the author gives an exhaustive +bibliography, beginning with the researches of Braconnot (1811), who +regarded the cellular tissue of these organisms as a specialised +substance, which he termed 'fungin.' Payen rejects this view, and +regards the tissue, fully purified by the action of solvents, as a +cellulose (C_{6}H_{10}O_{5}). This view is successively supported by +Fromberg [Mulder, Allg. Phys. Chem., Braunschweig, 1851], Schlossberger +and Doepping [Annalen, 52, 106], and Kaiser. De Bary, on a review of the +evidence, adopts this view, but, as the purified substance fails to give +the characteristic colour-reactions with iodine, he uses the qualifying +term 'pilzcellulose' [Morph. u. Biol. d. Pilze u. Flechten, Leipzig, +1884]. + +C. Richter, on the other hand, shows that these reactions are merely a +question of methods of purification or preparation [Sitzungsber. Acad. +Wien, 82, 1, 494], and considers that the tissue-substance is an +ordinary cellulose, with the ordinary reactions masked by the presence +of impurities. In regard to the lower types of fungoid growth, such as +yeast, the results of investigators are more at variance. The researches +of Salkowski (p. 113) leave little doubt, however, that the +cell-membrane is of the cellulosic type. + +The author's researches extend over a typical range of products obtained +from _Boletus edulis, Agaricus campestris, Cantharellus cibarius, +Morchella esculenta, Polyporus officinalis, Penicillium glaucum_, and +certain undetermined species. The method of purification consisted +mainly in (a) exhaustive treatments with ether and boiling alcohol, +(b) digestion with alkaline hydrate (1-2 p.ct. NaOH) in the cold, +(c) acid hydrolysis (2-3 p.ct. H_{2}SO_{4}) at 95°-100°, followed by a +chloroxidation treatment by the processes of Schulze or Hoffmeister, and +final alkaline hydrolysis. + +The products, i.e. residues, thus obtained were different in essential +points from the celluloses isolated from the tissues of phanerogams +similarly treated. Only in exceptional cases do they give blue reactions +with iodine in presence of zinc chloride or sulphuric acid. The +colourations are brown to red. They resist the action of cuprammonium +solutions. They are for the most part soluble in alkaline hydrate +solution (5-10 p.ct. NaOH) in the cold. They give small yields (1-2 +p.ct.) of furfural on boiling with 10 p.ct. HCl.Aq. + +Elementary analyses gave the following results, which are important in +establishing the presence of a notable proportion of nitrogen, which has +certainly been overlooked by the earlier observers:-- + + _________________________________________________________ +| | | | | +| 'Cellulose' or residue from | C | H | N | +|______________________________________|______|_____|_____| +| | | | | +| Boletus edulis (Schulze process) | 42.4 | 6.5 | 3.9 | +| Boletus edulis (Hoffmeister process) | 44.6 | 6.3 | 3.6 | +| Polyporus off. | 43.7 | 6.5 | 0.7 | +| Cantharellus cib. | 44.9 | 6.8 | 3.0 | +| Agaricus campestris | 44.3 | 6.6 | 3.6 | +| Botrytis | 42.1 | 6.3 | 3.9 | +| Penicillium glaucum | | | 3.3 | +| Morchella esculenta | | | 2.5 | +|______________________________________|______|_____|_____| + +It is next shown that this residual nitrogen is not in the form of +residual proteids (1) by direct tests, all of which gave negative +results, and (2) indirectly by the high degree of resistance to both +alkaline and acid hydrolysis. The 'celluloses' are attacked by boiling +dilute acids (1 p.ct. H_{2}SO_{4}), losing in weight from 10 to 23 +p.ct., the dissolved products having a cupric reduction value about 50 +p.ct. that of an equal weight of dextrose. As an extreme hydrolytic +treatment the products were dissolved in 70 p.ct. H_{2}SO_{4}, allowed +to stand 24 hours, then considerably diluted (to 3 p.ct. H_{2}SO_{4}) +and boiled to complete the inversion. The yields of glucose, calculated +from the cupric reduction, were as follows:-- + + Boletus edulis 65.2 p.ct. + Polyporus off. 94.7 " + Agaricus campestris 59.1 " + Morchella esculenta 60.1 " + Cantharellus cib. 64.9 " + Botrytis 60.8 " + +It will be noted that the exceptionally high yield from the Polyporus +cellulose is correlated with its exceptionally low nitrogen. By actual +isolation of a crystalline dextrorotary sugar, by preparations of +osazone and conversion into saccharic acid, it was proved that dextrose +was the main product of hydrolysis. The second main product was shown to +be acetic acid, the yield of which amounted to 8 p.ct. in several cases. + +Generally, therefore, it is proved that the more resistant tissue +constituents of the fungi are not cellulose, but a complex of +carbohydrates and nitrogenous groups in combination, the former being +resolved into glucoses by acid hydrolysis, and the latter yielding +acetic acid as a characteristic product of resolution together with the +nitrogenous groups in the form of an uncrystallisable syrup. + +In the further prosecution of these investigations (2) the author +proceeded from the supposition of the identity of the nitrogenous +complex of the original with chitin, and adopted the method of +Ledderhose (Ztschr. Physiol. Chem. 2, 213) for the isolation of +glucosamin hydrochloride, which he succeeded in obtaining in the +crystalline form. In the meantime E. Gilson had shown that these tissue +substances in 'fusion' with alkaline hydrates yield a residue of a +nitrogenous product (C_{14}H_{28}N_{2}O_{10}), which is soluble in +dilute acids [Recherches Chim. sur la Membrane Cellulaire des +Champignons, La Cellule, v. II, pt. 1]. This residue, which was termed +mycosin by Gilson, has been similarly isolated by the author. It is +proved, therefore, that the tissues of the fungi do contain a product +resembling chitin. [See also Gilson, Compt. Rend. 120, 1000.] This +constituent is in intimate union with the carbohydrate complex, which is +resolved similarly to the hemicelluloses. Various intermediate terms of +the hydrolytic series have been isolated. But the only fully identified +product of resolution is the dextrose which finally results. + + +UEBER DIE KOHLENHYDRATE D. HEFE. + +E. SALKOWSKI (Berl. Ber., 27, 3325). + +~ON THE CARBOHYDRATES OF YEAST.~ + +The author has isolated the more resistant constituents of the +cell-membrane by boiling with dilute alkalis, and exhaustively purifying +with alcohol and ether. + +The residue was only a small percentage (3-4 p.ct) of the original, and +retained only 0.45 p.ct. N. + +It was heated in a digester with water at 2-3 atm. steam-pressure, and +thus resolved into approximately equal portions of soluble cellulose +(a) and insoluble (b). The latter, giving no colour-reaction with +iodine, is termed achroocellulose; the former reacts, and is therefore +termed erythrocellulose. The former is easily separated from its +opalescent solution. It has the empirical composition of cellulose. In +the soluble form it resembles glycogen. The achroocellulose is isolated +in the form of horny or agglomerated masses. It appears to be resolved +by ultimate hydrolysis into dextrose and mannose. + + + + +SECTION V. FURFUROIDS, i.e. PENTOSANES AND FURFURAL-YIELDING +CONSTITUENTS GENERALLY + + +(1) ~Reactions of the Carbohydrates with Hydrogen Peroxide.~ + +C. F. CROSS, E. J. BEVAN, and CLAUD SMITH (J. Chem. Soc., 1898, 463). + + +(2) ~Action of Hydrogen Peroxide on Carbohydrates in the Presence of +Ferrous Salts.~ + +R. S. MORRELL and J. M. CROFTS (J. Chem. Soc., 1899, 786). + + +(3) ~Oxidation of Furfuraldehyde by Hydrogen Peroxide.~ + +C. F. CROSS, E. J. BEVAN, and T. HEIBERG (J. Ch. Soc., 1899, 747). + + +(4) EINWIRKUNG VON WASSERSTOFFHYPEROXID AUF UNGESÄTTIGTE +KOHLENWASSERSTOFFE. + +C. F. CROSS, E. J. BEVAN, and T. HEIBERG (Berl. Ber., 1900, 2015). + +~ACTION OF HYDROGEN PEROXIDE ON UNSATURATED HYDROCARBONS.~ + +The above series of researches grew out of the observations incidental +to the use of the peroxide on an oxidising agent in investigating the +hydrolysed furfuroids (102). Certain remarkable observations had +previously been made by H. J. H. Fenton (Ch. Soc. J., 1894, 899; 1895, +774; 1896, 546) on the oxidation of tartaric acid by the peroxide, +acting in presence of ferrous salts, the --CHOH--CHOH-- residue losing +H_{2} with production of the unsaturated group, --OH.C=C.OH--. These +investigations have subsequently been considerably developed and +generalised by Fenton, but as the results have no immediate bearing on +our main subject we must refer readers to the J. Chem. Soc., 1896-1900. + +From the mode of action diagnosed by Fenton it was to be expected that +the CHOH groups of the carbohydrates would be oxidised to CO groups, and +it has been established by the above investigations (1) and (2) that the +particular group to be so affected in the hexoses is that contiguous to +the typical + + | + --CO + +group. There results, therefore, a dicarbonyl derivative ('osone'), +which reacts directly with 2 mol. phenyl hydrazine in the cold to form +an osazone. This was directly established for glucose, lævulose, +galactose, and arabinose (2). While this is the main result, the general +study of the product shows that the oxidation is not simple nor in +direct quantitative relationship to the H_{2}O_{2} employed. The +molecular proportion of the aldoses affected appears to be in +considerable excess, and the reaction is probably complicated by +interior rearrangement. + +In the main, the original aldehydic group resists the oxidation. But a +certain proportion of acid products are formed, probably tartronic acid. +On distillation with condensing acids a large proportion of volatile +monobasic acids (chiefly formic) are obtained. The proportion of +furfural obtained amounts to 3-4 per cent. of the weight of the original +carbohydrate. + +Since the general result of these oxidations is the substitution of an +OH group for an H atom, it was of interest to determine the behaviour of +furfural with the peroxide. The oxidation was carried out in dilute +aqueous solution of the aldehyde at 20°-40°, using 2-3 mols. H_{2}O_{2} +per 1 mol. C_{5}H_{4}O_{2}. The main product is a hydroxyfurfural, which +was separated as a hydrazone. A small quantity of a monobasic acid was +formed, which was identified as a hydroxypyromucic acid. Both aldehyde +and acid appear to be the alpha beta derivatives. The aldehyde gives +very characteristic colour reactions with phloroglucinol and resorcinol +in presence of hydrochloric acid, which so closely resemble those of the +lignocelluloses that there is little doubt that these particular +reactions must be referred to the presence of the hydroxyfurfural as a +normal constituent. + +The study of these oxidations was then extended to typical unsaturated +hydrocarbons--viz. acetylene and benzene. (4) From the former the main +product was acetic acid, but the attendant formation of traces of ethyl +alcohol indicates that the hydrogen of the peroxide may take a direct +part in this and other reactions. This view receives some support from +the fact that the interaction of the H_{2}O_{2} with permanganates has +now been established to be an oxidation of the H_{2} of the peroxide by +the permanganate oxidation, with liberation, therefore, of the O_{2} of +the peroxide as an unresolved molecule [Baeyer]. + +Benzene itself is also powerfully attacked by the peroxide when shaken +with a dilute solution in presence of iron salts. The products are +phenol and pyrocatechol, with some quantity of an amorphous product +probably formed by condensation of a quinone with the phenolic products +of reaction. + + * * * * * + +These types of oxidation effects now established give a definite +significance to the physiological functions of the peroxide, which is a +form of 'active oxygen' of extremely wide distribution. It would have +been difficult _a priori_ to devise an oxidant without sensible action +on aldehydic groups, yet delivering a powerful attack on hydrocarbon +rings; or to have suggested a synthesis of the sugars from tartaric acid +with a powerful oxidising treatment as the first and essential stage in +the transformation. + +Our present knowledge of such actions and effects suggests a number of +new clues to genetic relationships of carbon compounds within the plant. +The conclusion is certainly justified that the origin of the pentoses is +referable to oxidations of the hexoses, in which this form of 'active +oxygen' plays an important part. + +We must note here the researches of O. Ruff, who has applied these +oxidations with important results in the systematic investigation of the +carbohydrates. + + +UEBER DIE VERWANDLUNG DER _D_-GLUCONSÄURE IN _D_-ARABINOSE (Berl. Ber., +1898, 1573). + +~CONVERSION OF _D_-GLUCONIC ACID INTO _D_-ARABINOSE.~ + + * * * * * + +_D_ UND _L_ ARABINOSE (_Ibid._ 1899, 550). + + * * * * * + +ZUR KENNTNISS DER OXYGLUCONSÄURE (_Ibid._ 1899, 2269). + +~ON OXYGLUCONIC ACID.~ + +Ruff in these researches has realised a simple and direct transition +from the hexoses to the pentoses. By oxidising gluconic acid with the +peroxide the beta --CHOH-- group is converted into carbonyl at the same +time that the terminal COOH [alpha] is oxidised to CO_{2}. The yields of +the resulting pentose are large. Simultaneously there is formed an +oxygluconic acid, which appears to be a ketonic acid of formula +--CH_{2}OH.CO.(CHOH)_{3}.COOH--. + +From these results we see a further range of physiological +probabilities; and with the concurrent actions of oxygen in the forms of +or related to hydrogen peroxide on the one side, and ozone on the other, +we are able to account in a simple way for the relationships of the +'furfuroid' group, which may include a number of intermediate terms in +the hexose-pentose series. + +Following in this direction of development of the subject is a study of +the action of persulphuric acid upon furfural. + + +EINWIRKUNG DES CARO'SCHEN REAGENS AUF FURFURAL. + +C. F. CROSS, E. J. BEVAN, and J. F. BRIGGS (Berl. Ber., 1900, 3132). + +Regarding this reagent as another form of 'active oxygen,' it is +important to contrast its actions with those of the hydrogen peroxide. +Instead of the beta-hydroxyfurfural (_ante_, 115) we obtain the +delta-aldehyde as the first product. The aldehydic group is then +oxidised, and as a result of attendant hydrolysis the ring is broken +down and succinic acid is formed, the original aldehydic group of the +furfural being split off in the form of formic acid. The reactions take +place at the ordinary temperature and with the dilute form of the +reagent described by Baeyer and Villiger (Ber. 32, 3625). These results +have some special features of interest. The alpha delta-hydroxyfurfural +has similar colour reactions to those of the alpha beta-derivative, and +may also therefore be present as a constituent of the lignocelluloses. +The tendency to attack in the 1·4 position in relation to an aldehydic +group further widens the capabilities of 'active oxygen' in the plant +cell. Lastly, this is the simplest transition yet disclosed from the +succinyl to furfural grouping, being effected by a regulated proportion +of oxygen, and under conditions of reaction which may be described as of +the mildest. In regard to the wide-reaching functions of asparagin in +plant life, we have a new suggestion of genetic connections with the +furfuroids. + + +VERGLEICH DER PENTOSEN-BESTIMMUNGSMETHODEN VERMITTELST PHENYLHYDRAZIN +UND PHLOROGLUCIN. + +M. KRÜGER (Inaug.-Diss., Göttingen, 1895). + +~COMPARISON OF METHODS OF ESTIMATING FURFURAL AS HYDRAZONE AND +PHLOROGLUCIDE.~ + +The author traces the development of processes of estimating furfural +(1) by precipitation with ammonia (furfuramide), (2) by volumetric +estimation with standardised phenylhydrazine, (3) by weighing the +hydrazone. + +In 1893 (Chem. Ztg. 17, 1745) Hotter described a method of quantitative +condensation with pyrogallol requiring a temperature of 100°-110° for +two hours. The insoluble product collected, washed, dried at 103°, and +weighed, gives a weight of 1.974 grm. per 1 grm. furfural. + +Councler substitutes phloroglucinol for pyrogallol, with the advantage +of doing away with the digestion at high temperature. (_Ibid._ 18, 966.) +This process, requiring the presence of strong HCl, has the advantage of +being applied directly to the acid distillate, in which form furfural is +obtained as a product of condensation of pentoses, &c. A comparative +investigation was made, precipitating furfural (a) as hydrazone in +presence of acetic acid, and (b) as phloroglucide in presence of HCl +(12 p.ct). In (a) by varying the weights of known quantities of +furfural, and using the factor, hydrazone × 0.516 [+ 0.0104] in +calculating from the weights of precipitates obtained, the maximum +variations from the theoretical number were +1.71 and -1.74. In (b) it +was found necessary to vary the factor from 0.52 to 0.55 in calculating +from phloroglucide to furfural. The greatest _total_ range of variation +was found to be 2.5 p.ct. The phenol process is therefore equally +accurate, has the advantages above noted, and, in addition, is less +liable to error from the pressure in the distillates obtained from +vegetable substances of volatile products, e.g. ketonic compounds, +accompanying the furfural. + +This method has been criticised by Helbel and Zeisel [Sitz.-ber, Wiener +Akad. 1895, 104, ii. p. 335] on two grounds of error, viz. (1) the +presence of diresorcinol in all ordinary preparations of phloroglucinol, +and (2) changes in weight of the precipitate of phloroglucide on drying. +The process was carried out comparatively with ordinary preparations, +and with specially pure preparations of the phenol. The quantitative +results were identical. The criticisms in question are therefore +dismissed. Although the process is to be recommended for its simplicity +and the satisfactory concordance of results it is to be noted that it +rests upon an empirical basis, since the phloroglucide is not formed by +the simple reaction 2 [C_{5}H_{4}O_{2} + C_{6}H_{6}O_{3}] - H_{2}O = +C_{22}H_{18}O_{9}, but appears to have the composition +C_{16}H_{12}O_{6}. + +In part ii. of this paper the author discusses the question of the +probable extent in the sense of diversity of constitution of +furfural-yielding constituents of plant-tissues. Glucoson was isolated +from glucosazon, and found to yield 2.9-3.6 p.ct. furfural. Gluconic +acid distilled with hydrochloric acid gave traces of furfural; so also +with sulphuric acid and manganic oxide. + +Starch was oxidised with permanganate, and a mixture of products +obtained of which one gave a characteristic violet colouration with +phloroglucol, with an absorption-band at the D line. On distilling with +HCl furfural was obtained in some quantity. The product in question was +found to be very sensitive to the action of bases, and was destroyed by +the incidental operation of neutralising the mixture of oxidised +products with calcium carbonate. It was found impossible to isolate the +compound. + + +UNTERSUCHUNGEN UEBER DIE PENTOSANBESTIMMUNG MITTELST DER +SALZSÄURE-PHLORO-GLUCIN-METHODE.[8] + +E. KRÖBER (Journ. f. Landwirthschaft, 1901, 357). + +~INVESTIGATION OF THE HYDROCHLORIC ACID-PHLOROGLUCINOL METHOD OF +DETERMINING PENTOSANES.~ + +This paper is the most complete investigation yet published of the now +well-known method of precipitating and estimating furfural in acid +solution by means of the trihydric phenol. In the last section of the +paper is contained the most important result, the proof that the +insoluble phloroglucide is formed according to the reaction + + C_{5}H_{4}O_{2} + C_{6}H_{6}O_{3} - 2H_{2}O = C_{11}H_{6}O_{3}, + +also, by varying the proportions of the pure reagents interacting, that +the condensation takes place invariably according to this equation. + +Incidentally the following points were also established:--The solubility +of the phloroglucide, under the conditions of finally separating in a +condition for drying and weighing, is 1 mgr. per 100 c.c. of total +solution, made up of the original acid solution, in which the +precipitation takes place, and the wash-water required to purify from +the acid. The phloroglucide is hygroscopic, and must be weighed out of +contact with the air. The presence of diresorcinol is without influence +on the result, provided a sufficient excess of actual phloroglucinol is +employed. Thus even with a preparation containing 30 p.ct. of its weight +of diresorcinol the influence of the latter is eliminated, provided a +weight be taken equal to twice that of the furfural to be precipitated. +The phenol must be perfectly dissolved by warming with dilute HCl (1.06 +sp.gr.) before adding to the furfural solution. For collecting the +precipitate of phloroglucide the author employs the Gooch crucible. + +The paper contains a large number of quantitative results in proof of +the various points established, and concludes with elaborate tables, +giving the equivalents in the known pentoses and their anhydrides for +any given weight of phloroglucide from 0.050 to 0.300 grm. + + +UEBER DEN PENTOSAN-GEHALT VERSCHIEDENER MATERIALIEN. + +B. TOLLENS and H. GLAUBITZ (J. für Landwirthschaft, 1897, 97). + +~ON THE PENTOSANE CONSTITUENTS OF FODDER-PLANTS AND MALT.~ + +(p. 171) (a) The authors have re-determined the yield of furfural from +a large range of plant-products, using the phloroglucol method. The +numbers approximate closely to those obtained by the hydrazone method. +The following may be cited as typical: + + Substance Furfural p.ct. + + Rye (Göttingen) 6.03 + Wheat (square head) 4.75 + Barley (peacock) 4.33 + Oats (Göttingen) 7.72 + Maize (American) 3.17 + Meadow hay 11.63 + Bran (wheat) 13.06 + Malt 6.07 + Malt-sprouts 8.56 + Sugar-beet (exhausted) 14.95 + +(b) A comparison of wheat with wheat bran, &c. was made by grinding in +a mortar and 'bolting' the flour through a fine silk sieve. The results +showed: + + Furfural p.ct. + Original wheat 4.75 + Fine flour 1.73 + Bran (24 p.ct. of wheat) 11.25 + Wheat-bran of commerce 13.06 + +It is evident that the pentosanes of wheat are localised in the more +resistant tissues of the grain. + +(c) An investigation of the products obtained in the analytical +process for 'crude fibre' gave the following: + +(1) In the case of brewers' grains: + + 100 grms. grains gave furfural = 29.43 pentosane + --------------- + 20 " crude fibre " = 2.52 + Acid extract " = 22.76 + Alkali " " = 1.20 + Deficiency from total of original grains 2.95 + ----- + + 29.43 + +(2) In the case of meadow hay: + +The crude fibre (30 p.ct.) obtained retained about one fourth (23.63 +p.ct.) of the total original pentosanes. + +(d) An investigation of barley-malt, malt-extract or wort, and +finished beer showed the following: An increase of furfuroids in the +process of malting, 100 pts. barley with 7.97 of 'pentosane' yielding 82 +of malt with 11.18 p.ct. 'pentosane'; confirming the observations of +Cross and Bevan (Ber. 28, 2604). Of the total furfuroids of malt about +1/4 are dissolved in the mashing process. In a fermentation for lager +beer it was found that about /10 of the total furfuroids of the malt +finally survive in the beer; the yield of furfural being 2.92 p.ct. of +the 'total solids' of the beer. In a 'Schlempe' or 'pot ale,' from a +distillery using to 1 part malt 4 parts raw grain (rye), yield of +furfural was 9 p.ct. of the total solids. + +In a general review of the relationships of this group of plant-products +it is pointed out that they are largely digested by animals, and +probably have an equal 'assimilation' value to starch. They resist +alcoholic fermentation, and must consequently be taken into account as +constituents of beers and wines. + + +UEBER DAS VERHALTEN DER PENTOSANE DER SAMEN BEIM KEIMEN.[9] + +A. SCHÖNE and B. TOLLENS (Jour. f. Landwirthschaft, 1901, 349). + +~BEHAVIOUR OF PENTOSANES OF SEEDS IN GERMINATION.~ + +The authors have investigated the germination of barley, wheat, and +peas, in absence of light, and generally with exclusion of assimilating +activity, to determine whether the oxidation with attendant loss of +weight, which is the main chemical feature of the germination proper, +affects the pentosanes of the seeds. The following are typical of the +quantitative results obtained, which are stated in absolute weights, and +not percentages. + + _____________________________________________________________ +| | | | | +| | Original seed | Malt or | Pentosane in | +| | | germinated product | | +| | | |_______________| +| | | | | | +| | A | B | A | B | +|________|_______________|____________________|_______|_______| +| | | | | | +| Barley | 500.00 | 434.88 | 39.58 | 40.38 | +| " | 500.00 | 442.26 | 40.52 | 41.17 | +| Peas | 300.00 | 286.60 | 15.25 | 15.97 | +|________|_______________|____________________|_______|_______| + +The authors conclude generally that there is a slight absolute increase +in the pentosanes, and that the pentosanes do not belong to those +reserve materials which undergo destructive oxidation during +germination. + +In this they confirm the previously published results of De Chalmot, +Cross and Bevan, and Gotze and Pfeiffer. + + +UEBER DEN GEHALT DER BAUMWOLLE AN PENTOSAN. + +H. SURINGAR and B. TOLLENS (Ztschr. angew. Chem., 1897, I). + +~PENTOSANE CONSTITUENTS OF COTTON.~ + +(p. 290) It has been stated by Link and Voswinkel (Pharm. Centralhalle, +1893, 253), that raw cotton yields 'wood gum' as a product of +hydrolysis. The authors were unable to obtain any pentoses as products +of acid hydrolysis of raw cotton, and traces only of furfural-yielding +carbohydrates. They conclude that raw cotton contains no appreciable +quantity of pentosane. + +FOOTNOTES: + +[8] This paper appears during the printing of the author's original MS. + +[9] This paper appears during the printing of the author's original MS. + + + + +SECTION VI. THE LIGNOCELLULOSES + + +(p. 131) ~Lignocellulose Esters.~--By a fuller study of the ester +reactions of the normal celluloses we have been able to throw some light +on the constitutional problems involved; and we have extended the +investigations to the jute fibre as a type of the lignocelluloses, from +the results of which we get a clearer idea of the relationships of the +constituent groups. + +Taking the empirical expression for the complex, i.e. the entire +lignocellulose, the formula C_{12}H_{18}O_{9}, we shall be able to +compare the ester derivatives with those of the celluloses, which we +have also referred to a C_{12} unit. But we shall require also to deal +with the constituent groups of the complex, which for the purposes of +this discussion may be regarded as (a) a cellulose of normal +characteristics--cellulose alpha; (b) a cellulose yielding furfural on +boiling with condensing acids--cellulose beta; and (c) a much +condensed, and in part benzenoid, group which we may continue to term +the lig_none_ group. + +The latter has been specially examined with regard to its proportion of +OH groups, as a necessary preliminary to the investigation of esters, in +producing which the entire complex is employed. It will be shown that +the ester groups can be actually localised in various ways, as in the +main entering the cellulose residues alpha and beta. But that the +lignone group takes little part in the reactions may be generally +concluded on the evidence of its non-reactivity as an isolated +derivative, (1) By chlorination, &c. it is isolated in the form of an +amorphous body, but of constant composition, represented by the formula +C_{19}H_{18}Cl_{4}O_{9}. This compound, soluble in acetic anhydride, was +boiled with it for six hours after adding fused sodium acetate, and the +product separated by pouring into water. The dilute acid filtered from +the product contained no hydrochloric acid nor by-products of action. +The product showed an increase of weight of 7.5 p.ct. For one acetyl per +1 mol. C_{19}H_{18}Cl_{4}O the calculated increase is 8.0 p.ct. It is +evident from the nature of the derivative that this result cannot be +further verified by the usual analytical methods. (2) The chlorinated +derivative is entirely soluble in sodium sulphite solution. This +solution, shaken with benzoyl chloride, with addition of sodium hydrate +in successive portions, shows only a small formation of insoluble +benzoate, which separates as a tarry precipitate. (3) The empirical +formula of the lignone complex in its isolated forms indicates that very +little hydrolysis occurs in the processes of isolation. Thus the +chlorinated product we may assume to be derived from the complex +C_{19}H_{22}O_{9}. In the soluble by-products from the bisulphite +processes of pulping wood the lignone exists as a sulphonated +derivative, C_{24}H_{23}(OCH_{3})_{2}.(SO_{3}H).O_{7}. The original +lignone may be regarded as passing into solution as a still condensed +complex derived from C_{24}H_{26}O_{12} (Tollens). There is evidently +little attendant hydroxylation, and another essential feature is the +small molecular proportion of groups showing the typical sulphonation. + +It appears that in the lignone the elements are approximately in the +relation C_{6} : H_{6} : O_{3}, and it may assist this discussion to +formulate the main constitutional types consistent with this ratio, +viz.: + + (1) The trihydroxybenzenes C_{6}H_{3}(OH)_{3}. + + (2) Methylhydroxyfurfural C_{5}H_{2}O.(OH)(CH_{3}). + + (CH_{3}) + / \ + (3) Methylhydroxypyrone CO<C_{4}H_{2} O + \ / + (OH) + + __________________ + | | + (4) Trioxycyclohexane CH--CH--CH--CH--CH--CH + \ / \ / \ / + O O O + +It is probable that all these types of condensation are represented in +the lignone molecules, since the derivatives yielded in decompositions +of more or less regulated character are either directly derived from or +related to such groups. For the moment we pass over all but the general +fact of complexity and the marked paucity of OH-groups. It would be of +importance to be able to formulate the exact mode of union of the +lignone with the cellulose residues to constitute the lignocellulose. +The evidence, however, does not carry us farther than the probability of +union by complicated groups and of large dimensions; for not only is the +lignone isolated in condensed and non-hydroxylated forms, but the +cellulose also is not hydrated or hydrolysed further than in the ratio +3C_{6}H_{10}O_{5}.H_{2}O. It is probable, therefore, that the water +combining with the residues at the moment of their resolution is +relatively small. + +Lastly, we have to remember, when dealing with the statistical results +of the reactions to be described, that the approximate proportions per +cent. of the constituent groups are: + + Cellulose alpha 65 + " beta 15 = 100 lignocellulose. + Lignone 20 + +~Jute Benzoates.~--In preparing the jute for treatment it was boiled in +alkaline solution (1 per cent. NaOH), washed with water and dilute acid, +again washed, dried, and weighed. + +In the ester reaction the reagents were employed in the proportion +C_{12}H_{18}O_{9} : 3NaOH : 2C_{6}H_{5}COCl. A series of quantitative +experiments gave yields of 126-130 p.ct. of benzoate [calculated for +monobenzoate 134 p.ct.]. + +The results were confirmed by ultimate analysis. The monobenzoate +therefore represents a maximum, and this molecular proportion is +one-half of that observed with the normal cellulose, calculated to the +same unit. + +_Localisation of Benzoyl Group._--The entrance of the ester group +affects the typical colour reactions of the lignocellulose, which are +fainter. The ferric ferricyanide reaction almost disappears. The lignone +group is unaffected, and combines with chlorine as in the original. The +lignone chloride is removed by sodium sulphite solution, and the residue +is a _cellulose benzoate_. The loss of weight due to the elimination of +the lignone was 12.7 p.ct. Calculating per 100 of the original +lignocellulose this becomes 16. These statistics further confirm the +localisation of the benzoyl group in the cellulose residue. It is to be +noted that the presence of the benzoyl group renders the cellulose more +resistant to hydrolytic actions. Thus, to bring out this fact more +prominently, we may calculate the yield of residual cellulose benzoate +p.ct. of original jute, and we find it 109 p.ct. Taking a maximum +proportion for original cellulose--viz. 85--this benzoate represents a +yield of 129 p.ct., as against the theoretical for a monobenzoate, 132 +p.ct. + +_Furfural Numbers._--The percentage of furfural obtained by boiling with +HCl of 1.06 sp.gr. was 3.02 and 3.29 in separate determinations. +Calculating to the original lignocellulose, the percentage, 4.21, +indicates a considerable loss of the furfural-yielding constituent. The +effect was also apparent in the cellulose (benzoate) isolated by +chlorination &c., the percentage being 1.39 p.ct., and calculated to the +original jute benzoate 1.59 p.ct. Under the conditions adopted in +dissolving away the chlorinated lignone the original non-benzoated +lignocellulose would have yielded a cellulose giving 6 to 7 p.ct. +furfural. + +Since the benzoyl group is hardly calculated to produce a constitutional +change affecting the furfural constants, it was necessary to examine the +effect of the preliminary alkaline treatment, and the change in the +furfuroid group was in fact localised in this reaction. It was found +that, on washing the alkali from the mercerised jute, and further +purifying the residue, this latter yielded only 4.2 p.ct. furfural [3.4 +p.ct. on original fibre]. The alkaline solution and washings were +acidified and distilled from 10 p.ct. HCl, yielding an additional 3.6 +p.ct. calculated to the original lignocellulose. By treatment with the +concentrated alkali, therefore, the furfuroid of the original +lignocellulose undergoes little change, but is selectively dissolved. +This point is under further investigation. + +(p. 132) ~Acetylation of Lignocelluloses.~--Acetates are readily formed by +boiling the lignocelluloses with acetic anhydride. The derivatives +obtained from jute are only generally mentioned in the 1st edition (p. +132). A further study of the reactions in regard to special points has +led to some more definite results. The _yields_ of product by the +ordinary and simple process are 114-115 p.ct. But on analysing the +product an important discrepancy is revealed. + +For the saponification we employ a solution of sodium ethylate in the +cold. The following numbers were obtained: + + Acetic acid Hydrocellulose residue + 27.2 77.8 +Calc. for diacetate on C_{12}H_{18}O_{9} 30.8 78.4 + +The derivative is approximately a diacetate, and on the assumption of a +simple ester reaction the yield should be 127 p.ct. Assuming that the +difference of 13 p.ct. is due to loss of water by internal condensation, +it appears that for each acetyl group entering, 2 mol. H_{2}O are split +off. + +The jute acetate showed the normal reaction with chlorine, and the +lignone chloride was dissolved by treatment with sodium sulphite +solution. The fibrous residue was colourless. It proved to be a +cellulose acetate. The following numbers were obtained on +saponification: + + Acetic acid Cellulose + 31.6 70.0 + 30.9 68.8 +Calc. for diacetate on C_{12}H_{20}O_{10} 29.4 79.9 + +The interpretation of these numbers appears to be this: in the original +reaction with the lignocellulose it is the cellulose residue which is +acetylated, and at the same time condensed. The cellulose residue which +undergoes condensation is not of the normal constitution, since the +normal cellulose is acetylated without condensation (see p. 41). On +saponification a portion of the cellulose, in again combining with +water, is hydrolysed to soluble products. The lignone group as it exists +in the lignocellulose has no free OH groups, and probably no free +aldehydic groups such as would react with the anhydride. Such groups +may, however, be originally present, and may take part in the internal +condensations which have been shown to occur. The furfural constants of +the lignocellulose are unaffected by the acetylation and condensation. +The hygroscopic moisture of the product is lowered from 10-11 p.ct. in +the original to 4.5 p.ct. The ferric ferricyanide reaction is inhibited +by the disappearance of the reactive groups, upon which this curious and +characteristic phenomenon depends (1st ed.). + +~Acetylation of Benzoates.~--The cellulose dibenzoate (C_{12} basis) and +the jute monobenzoate were acetylated under comparative conditions The +results were as follows: + + C_{12} basis + Cellulose dibenzoate Jute monobenzoate + Calc. for Calc. for + Found diacetate on Found diacetate on +Ester reaction dibenzoate monobenzoate +Yield 111 p.ct. 115 p.ct. 124 p.ct. 120 p.ct. + +Saponification {Cellulose} + {Lignocellulose} 53.5 52.6 59.8 61.9 + NaOH combining 21.3 23.9 28.4 24.3 + +From these results it would appear that the number of acetyl groups +entering the benzoates is the same as with the unbenzoylated fibres, the +benzoyl has no influence upon the hydroxyls as against the acetyl. At +the same time the internal condensation noticed in the acetylation of +the jute appears not to occur in the case of the benzoate. + +~Nitric Esters.~--The numbers resulting from the quantitative study of the +ester reaction and product (1st ed. p. 133) show a very large divergence +of the yield of product from that which would be calculated from its +composition (N p.ct.) on the assumption that the ester reaction is +simple. We have repeated the results, and find with a yield of 145 p.ct. +that the product contains 11.8 p.ct. N. + +The reaction + + C_{12}H_{18}O_{9} + 4HNO_{3} - 4H_{2}O + +gives a tetranitrate with 11.5 p.ct. N and a yield of 159 p.ct. The +ester reaction, therefore, is not simple. There are two sources of the +loss of weight. The first of these is evident from the occurrence of +certain secondary reactions which result in the solution of a certain +proportion of the fibre substance in the acid mixture. To determine this +quantitatively we have devised a suitable variation of the method of +combustion with chromic acid (1st ed.). + +The variation is required to meet the difficulty occasioned by the +tension of the nitric acid and products of deoxidation. The mixed acids +(10 c.c.), containing the organic by-products in solution, are +carefully diluted in a small flask with an equal volume of water, +preventing rise of temperature. Nitrous fumes are evolved during the +dilution. Strong sulphuric acid (15 c.c.) is now added, and the residue +of nitrous fumes expelled by a current of air, agitating the contents of +the flask from time to time. The combustion with CrO_{3} is then +proceeded with in the ordinary way. The gases evolved are measured +(total volume) and calculated to C present in the form of products +derived from the lignocellulose; and, assuming that this contains 47 +p.ct. C, we may express the result approximately in terms of the fibre +substance. The method was controlled by blank experiments, in which +citric acid was taken as a convenient carbon compound for combustion. +The C found was 34.9 p.ct. as against 34.3 p.ct. calculated. By this +method we find that with maximum yields of nitrate at 143-145 p.ct. the +organic matter in solution in the acid mixture amounted to 4.9 to 5.3 +p.ct. of the original lignocellulose. + +Introducing this quantity as a correction of the yield of nitrate in the +original reaction, we must express the 143 parts as obtained from 95 of +fibre substance instead of 100. + +The yield per molecule C_{12}H_{18}O_{9} (= 306) is therefore 462, +whereas for a tetranitrate formed by a simple ester reaction the yield +should be 486. The difference (24) represents 1.5 mol. H_{2}O split off +by internal condensation. + +The correction for total N is relatively small, raising it from 11.5 to +12.2, which remains in close agreement with the experimental numbers. + +_Monobenzoate._--Treated with the acid mixture yields a mixed nitrate. +The yield is 130 p.ct., and the product contains 7.6 p.ct. O.NO_{2} +nitrogen. These numbers approximate to those required for reaction with +4HNO_{3} groups, three of the residues entering the cellulose, and one +(as NO_{2}) the benzene ring of the substituting group. For such a +reaction the calculated numbers are: Yield 144 p.ct.; O.NO_{2} nitrogen +7.1 p.ct. + +The experimental numbers require correcting for the amount of loss in +the form of products soluble in the acid mixture, viz. 7.6 p.ct.; but +they remain within the range of the experimental errors sufficiently to +show that the benzoyl group limits the number of OH groups taking part +in the ester reaction to three. The corrected yield per 1 mol. of jute +benzoate (410) is 576, as against the calculated 590 for 4HNO_{3} +reacting. A loss of 1H_{2}O per molecule by internal condensation is +therefore indicated. + +~Denitration.~--The removal of the nitric groups from the esters is +effected by digestion with ammonium sulphide. But the reactions are by +no means simple. There is considerable hydrolysis of the lignocellulose +to soluble products. Thus the _tetranitrate_ yields only 46.4 of +denitrated fibre in place of the calculated 66. The product is a +cellulose, yielding only 0.5 per cent. furfural. The hydrolysed +by-products, moreover, when freed from sulphur and distilled from +hydrochloric acid, yielded only an additional 2.5 p.ct. furfural, +calculated to the original lignocellulose. + +These statistics confirm the evidence that the ester reaction is not +simple. Such changes take place in the lignone-beta-cellulose complex +that they revert, not to their original form, but to soluble derivatives +of different constitution. The mixed nitrate from the benzoate is +denitrated to a cellulose amidobenzoate, which confirms the localisation +of a nitro-group in the benzoyl residue. + +(p. 157) ~General Characteristics of the Lignocelluloses.~--Later +investigations have somewhat modified and simplified our views of the +constitution of the typical lignocellulose (jute), so far as this can be +dealt with by the statistics of its more important decompositions +(original, pp. 157-161). + +~Cellulose.~--There is little doubt that the furfural-yielding groups of +the original are isolated in the form of the beta-cellulose. Tollens +emphasises this fact in his studies of cellulose-estimation methods. We +had previously shown (original, p. 159) that the yield of furfural is +not affected by the _chlorination_, but it appears from our numbers that +only 50 p.ct. of these groups remain in the isolated cellulose, the +residue undergoing hydrolysis to soluble compounds. In a carefully +regulated hydrolysis following the chlorination it appears that the +furfuroids are almost entirely conserved in the form of a cellulose. + +Moreover, an investigation of the products dissolved by sodium sulphite +solution from the chlorinated fibre has shown that they are practically +free from furfuroids. This enables us to exclude the furfural-yielding +groups from the lignone complex. At the same time, through our later +studies of the hydroxyfurfurals, it is certain that these products are +represented in the fibre substance and probably in the lignone complex. + +~Chlorination Statistics.~--It has been pointed out by a correspondent--to +whom we express our indebtedness--that we have made a mistake in +calculating the proportion of lignone from the ratio of the Cl combining +with the fibre substance or lignocellulose (p.ct), to that of the Cl +_present in_ the isolated lignone chloride (p.ct.). The lignocellulose +combines with chlorine in the ratio 100 : 8, but the lignone chloride +_containing_ 26.7 of chlorine means that, neglecting the hydrogen +substituted, 73 of lignone combine with the 27 of chlorine +approximately. On the uniform percentage basis the calculated proportion +of lignone would be 8/37, or a little over 20 p.ct. + +In regard to the proportion of hydration attending the resolution, we +have shown on constitutional grounds that this must be relatively small. +Assuming approximately the formula C_{19}H_{22}O_{9} for the lignone +residue as it exists in combination, and the anhydride formula for the +cellulose, these revised statistics now appear, as regards the carbon +contents of the lignocellulose: + + Cellulose, 44.4 C; lignone, 57.8. + 80 × 44.4 ÷ 100 = 35.52 + 20 × 57.8 ÷ 100 = 11.56 + _____ + + 47.08 p.ct. C in lignocellulose. + +These conclusions are in accordance with the experimental facts, and, +taken together with the new evidence we have accumulated from a study of +the lignocellulose esters, we may sum up the constitutional points as +follows: The lignocellulose is a complex of + + Cellulose alpha Cellulose beta Lignone + 65 p.ct. 15 p.ct. 20 + Allied to the normal Yielding furfural One-third of which + celluloses approximately 50 p.ct. is of benzenoid + type + +The lignone contains but little hydroxyl. The celluloses are in +condensed hydroxyl union with the lignone, but the combination occurs by +complexes of relatively large molecular weight. + + +DIE CHEMIE DER LIGNOCELLULOSEN--EIN NEUER TYPUS. + +W. C. HANCOCK and O. W. DAHL (Berl. Ber., 1895, 1558). + +~Chemistry of Lignocelluloses--A New Type.~ + +The stem of the aquatic _Æschynomene aspera_ offers an exceptional +instance of structural modification to serve the special function of a +'float,' 1 grm. of substance occupying an apparent volume of 40-50 c.c. +This pith-like substance is morphologically a true wood (De Bary), and +the author's investigations now establish that it is in all fundamental +points of chemical composition a lignocellulose, although from its +colour reactions it has been considered by botanists to be a cellulose +tissue containing a proportion of lignified cells. Thus the main tissue +is stained blue by iodine in presence of hydriodic acid (1.5 s.g.), and +the colour is not changed on washing. The ordinary lignocelluloses are +stained a purple brown changed to brown on washing. The reactions with +phloroglucol and with aniline salts, characteristic of these compounds, +is only faintly marked in the main tissue, though strongly in certain +individual cells. + +The following quantitative determinations, however, establish the close +similarity of the product to the typical lignocelluloses: + +_Elementary Analysis._--C 46.55, H 6.7. _Furfural_ 11.6 p.ct., of which +there remained in the residue from alkaline hydrolysis (71 p.ct.) 8.0, +i.e. about 70 p.ct. The distribution of the furfuroids is therefore not +affected by the alkaline treatment. + +_Chlorination._--The substance (after alkaline hydrolysis) takes up 16.9 +p.ct. Cl, of which approximately one-half is converted into hydrochloric +acid. + +_Methoxyl._--O.CH_{3} estimated = 2.9 p.ct. + +_Ferric Ferricyanide Reaction._--Increase of weight due to blue cyanide +fixed (1) 75 p.ct., (2) 96 p.ct. Ratio, Fe : CN = 1 : 2, 4. + +_Hydroxyl Reactions._--In the formation of nitric esters and in the +sulphocarbonate reaction the substance gave results similar to those +obtaining for the jute fibre. + +These results establish the general identity of this peculiar product of +plant life with the lignocelluloses, at the same time that they show +that certain of the colour reactions supposed to characterise the +lignocelluloses are due to by-products which may or may not be present. + +(p. 172) ~Composition of Elder Pith.~--In a systematic investigation of +the celluloses in relation to function we shall have to give special +attention to the parenchymatous tissues of all kinds. These are, for +structural reasons, not easily isolated, for which reason and their +generally 'inferior' functions they do not present themselves to +chemical observation in the same obvious way as do their fibrous +relatives. The pith of the elder, however, _is_ readily obtained in +convenient masses, and a preliminary investigation of the entire tissue +has established the following points: + +The _reactions_ of the tissue are in all respects those of the +lignocelluloses. + +_Composition._--Ash, 2.2 p.ct.; moisture in air-dry state, 12.3 p.ct. +Alkaline hydrolysis (loss): (a) 14.77, (b) 17.84. Cellulose (yield), +52.33 p.ct. Nitrate-reaction complicated by secondary reactions and +yields low, 90.95 p.ct. _Sulphocarbonate reaction:_ Resists the +treatment, less than 10 p.ct. passes into solution. + +_Furfural._--The original tissue yields 7.13 p.ct.; the residue from +alkaline hydrolysis (b) 5.40 p.ct. + +This tissue is, therefore, a lignocellulose having the chemical +characteristics typical of the group, but of less resistance to +hydrolytic actions. + +The investigation will be prosecuted in reference to the cause of +differentiation in this latter respect. Probably the pectocelluloses are +represented in the tissue. + + +~The Insoluble Carbohydrates of Wheat (grain).~ + +H. C. SHERMAN (J. Amer. Chem. Soc., 1897, 291). + +(p. 171) This is a study of the constituents of the cell-walls of wheat +grain. Bran was taken as the most convenient form of the raw material, +being freed from starch by treatment with malt extract, and further +treated (1) with cold dilute ammonia, (2) cold dilute soda lye (2 p.ct. +NaOH), and (3) boiling 0.1 p.ct. NaOH. The product retained only 1.25 +p.ct. proteids, and yielded 15.62 p.ct. furfural. + +_Acid Hydrolysis._--The product was boiled 30 mins. with dilute acid +(1.25 p.ct. H_{2}SO_{4}), and the solution boiled until the Fehling test +showed no further increase of monoses. At the limit the reducing power +of the dissolved carbohydrates was 91.3 p.ct., that of dextrose. +Converted into osazones the analysis showed them to be _pure +pentosazones_. The _hemicellulose_ of wheat is, therefore, according to +the author, _pure pentosane_. + +_Residue._--This was a lignocellulose yielding 11.5 p.ct. furfural. It +was subjected to a series of treatments with ferric ferricyanide, and +the proportion of Prussian blue fixed was determined by increase of +weight, viz. from 10 p.ct. to 47 p.ct. according to the conditions. The +results confirmed those of Cross and Bevan first obtained with the +typical lignocellulose (jute). + +_Chlorination._-The residue was boiled with dilute alkali, washed, and +exposed to chlorine gas. The resulting lignone chloride was isolated by +solution in alcohol, &c. It yielded 26.7 p.ct. Cl on analysis. In this +and its properties it appeared to be identical with the product isolated +by Cross and Bevan from jute, with the empirical formula +C_{19}H_{18}Cl_{4}O_{9}. + +_Cellulose_ was isolated from the residue by three of the well-known +methods, and the following comparative numbers are noteworthy: + + _________________________________________________________________________ +| | | | | +| | F. Schulze | Lange | Cross and | +| Method | Dil. HNO_{3} | Fusion KOH | Bevan | +| | KClO_{3} | | Chlorine, &c. | +|_____________________________|______________|____________|_______________| +| | | | | +| Cellulose p.ct. obtained | 66.0 | 39.3-43.1 | 66.5 | +| Furfural p.ct. of cellulose | 7.0 | 3.96 | 5.62 | +| Residual nitrogen | 0.22 | 0.03 | 0.00 | +| Ferricyanide reaction, | | | | +| Prussian blue fixed | 6.04 | 0.89 | 0.92 | +|_____________________________|______________|____________|_______________| + +The author remarks: 'It is evident no one feature can be urged as a +criterion in judging between the methods, but all must be taken into +consideration. Such a comparison shows the superiority of the +chlorination method.' + +The cellulose is not of the normal (cotton) type, since on treatment +with sulphuric acid it dissolves with considerable discolouration, but +only to the extent of about 80 per cent. The dissolved monoses converted +into osazones were found to consist of hexoses only. The cellulose +treated with caustic soda solution (5 p.ct. NaOH) in the cold yielded 20 +p.ct. of its weight of soluble constituents, but as the residue yielded +3.34 p.ct. furfural the attack of the alkali is by no means confined to +the furfuroids. + +~Animal Digestion of the Constituents of Bran.~--Observations on a steer +fed upon wheat bran only established the following percentage digestion +of the several constituents: + + Soluble carbohydrates 96.9 + Starch 100.0 + Free pentosanes 60.2 + Cellulose 24.8 + Lignin complex 36.7 + Proteid 82.96 + Ether extract 42.73 + _____________________ ______ + + Nitrogen-free extract 76.08 + Crude fibre 32.21 + + +JOURNAL OF THE IMPERIAL INSTITUTE + +(Research Department, Vols. 1-2, 1895-6). + +(p. 109) In this journal appear a series of notices of the results of +analyses of vegetable fibres by the method described in 'Report on +Miscellaneous Fibres' (Col. Ind. Exhibition Reports, p. 368) [C. F. +Cross]. These investigations deal with the following subjects: + +1895. p. 29 Various Indian Fibres--more particularly Sida. + 118 (a) Fibres from Victoria; (b) Special Analyses of + (a) Samples of Jute; (c) Paper-making Fibres + from S. Australia. + 202 Fibres from Victoria. + 287 Fibres from Victoria. + 366 Sisal from Trinidad. + 373 Rope-fibres from Grenada. + (b) 398 Report of Experiments on Indian Jute (1). + 435} Fifth and Sixth Report on Australian Fibres. + 473} +1896. 68 Hibiscus and Abroma Fibres. + 104-5 Hibiscus, Urena, and Crotalaria Fibres. + 141 Indian Sisal + (c) 182-3 Report of Experiments on Indian Jute (2). + 264 Sanseviera from Assam. + +From the above we may draw the general conclusion that the scheme of +investigation has been found in practice to answer its main purpose, +viz. to afford such numerical constants as determine industrial values. +In illustration we may cite (a) the results of analyses of specially +selected samples of jute, from which it will be seen that there is a +close concordance of value as ordinarily determined from external +appearance, with the chemical constants as determined in the laboratory. + + __________________________________________________________________ +| | | +| | Quality of Jute | +|____________________________|_____________________________________| +| | | | | | +| | Low | Medium | Extra | Extra Fine | +|____________________________|_______|________|_______|____________| +| | | | | | +| Moisture | 11.0 | 10.4 | 11.1 | 9.6 | +| Ash | 0.87 | 2.8 | 1.0 | 0.7 | +| Alkaline hydrolysis (a) | | | | | +| 5 mins. boiling | 13.2 | 11.6 | 8.5 | 9.1 | +| Alkaline hydrolysis (b) | | | | | +| 60 mins. boiling | 16.1 | 17.5 | 12.5 | 13.1 | +| Mercerising treatment | 9.2 | 10.5 | 10.3 | 8.5 | +| Nitration (increase p.ct.) | 36.6 | 35.7 | 37.5 | 36.7 | +| Cellulose (yield) | 71.4 | 70.0 | 79.0 | 77.7 | +| Acid purification | 2.6 | 1.3 | 1.9 | 2.0 | +|____________________________|_______|________|_______|____________| + +A useful series of experiments, initiated by the Institute, is that +noted under (b) and (c) above. + +(1) To ascertain the quality of the fibre extracted from the plant at +different stages of growth, quantities of 400 lbs. of the stalks were +cut at successive stages and the fibre isolated after steeping 14-20 +days. The fibre was shipped to England and chemically investigated, with +the following results: + +No. 1. Cut before appearance of inflorescence. + " 2. " after budding. + " 3. " in flower. + " 4. " after appearance of seed-pod. + " 5. " when fully matured. + + _________________________________________________________________ +| | | | | | | +| | (1) | (2) | (3) | (4) | (5) | +|___________________________|_______|_______|______|______|_______| +| | | | | | | +| Moisture | 11.55 | 8.74 | 10.7 | 10.0 | 9.72 | +| Ash | 1.1 | 1.1 | 1.1 | 1.1 | 0.90 | +| Alkaline hydrolysis (a) | 6.2 | 8.5 | 9.7 | 8.9 | 7.3 | +| " " (b) | 10.5 | 11.9 | 11.6 | 12.0 | 11.2 | +| Mercerising treatment | 10.2 | 10.7 | 12.0 | 8.1 | 11.0 | +| Nitration | 37.2 | 32.1 | 32.2 | 33.2 | 36.6 | +| Cellulose | 74.0 | 76.2 | 74.1 | 74.8 | 76.4 | +| Acid purification | 0.8 | 0.5 | 0.7 | 2.4 | 1.4 | +|___________________________|_______|_______|______|______|_______| + +It will be thus seen that there are no changes of any essential kind in +the chemical composition of the bast fibre throughout the life-history +of the plant, confirming the conclusion that the 'incrustation' view of +lignification is consistent only with the structural features of the +changes, and so far as it has assumed the gradual overlaying of a +cellulose fibre with the lignone substance it is not in accordance with +the facts. + +Examination of the samples from the point of view of textile quality +showed a superiority of No. 1 in fineness, softness, and strength; from +this stage there is observed a progressive deterioration, but the No. 4 +sample (which was taken at the usual period of cutting) is superior to +No. 5. + +In a further series of experiments (c) the jute was subjected to +certain chemical treatments immediately after the separation of the +fibre from the plant. These consisted in steeping (1) in solution of +sodium carbonate, as well as of plant ashes, and (2) in sulphite of +soda, the purpose of the treatments being to modify or arrest the +changes which take place in the fibre when press-packed in bales for +shipment. The samples were shipped from India under the usual conditions +and examined soon after arrival. It was found that the chemical +treatments had produced but small changes in chemical composition of the +fibre-substance. The sulphite treatment was the more marked in +influence, somewhat lowering the cellulose and nitration constants. The +conclusion drawn from the results was that they afford no prospect of +any useful modification, i.e. improvement of the textile quality of the +fibre by any chemical treatments such as could be applied to the fibre +on the spot before drying for press-packing and shipment. + +The other matters investigated in the Institute laboratory and reported +on as indicated above are rather of commercial significance, and +contributed no points of moment to the chemistry of cellulose. + + +OBSERVATIONS ON SOME OF THE CHEMICAL SUBSTANCES IN THE TRUNKS OF TREES. + +F. H. STORER (Bull. Bussey Inst., 1897, 386). + +(p. 172) An examination of the outer and inner wood and of the bark of +the grey birch, at different seasons of the year, gave the following +yields of furfural p.ct. on the dry substance: + + ________________________________ +| | | | +| | Wood | | +| |_______________| Bark | +| | | | | +| | Inner | Outer | | +|_________|_______|_______|______| +| | | | | +| May | 21.3 | 19.6 | 16.7 | +| July | 16.6 | 18.8 | 11.4 | +| October | 16.2 | 16.3 | 12.3 | +|_________|_______|_______|______| + +The paper contains the results of treating the woods and various +vegetable products with hydrolysing agents in order of intensity: (a) +Malt-extract at 60°C., (b) boiling dilute HCl (1.0 p.ct. HCl), and +(c) boiling dilute HCl (2.5 p.ct.). The residues were found to yield +considerable proportions of furfural. The following numbers are typical: + + ________________________________________________________________________ +| | | | +| | Birch | Stones of | +| |_____________|__________________________| +| | | | | | | +| | Bark | Wood | Date | Apricot | Peach | +|_______________________________|______|______|________|_________|_______| +| | | | | | | +| Action of malt extract calcu- | | | | | | +| lated as starch dissolved | 4.24 | 3.5 | 5.2 | 1.5 | -- | +| | | | | | | +| Residue boiled, 1 p.ct. HCl | | | Mannan | | | +| gave pentosanes dissolved. | -- | -- | 11.7 | 14.1 | 6.7 | +| | | | | | | +| Residue yielded furfural | 19.3 | 17.8 | 3.4 | 9.6 | 9.7 | +|_______________________________|______|______|________|_________|_______| + +The proportion of pentosanes (furfuroids) removed, i.e. hydrolysed by +boiling with hydrochloric acid of 2.5 p.ct. HCl, is shown by the +following estimations of furfural: + + _________________________________________________________________ +| | | | | +| | Birch | Sugar maple | | +| |______________|_______________| Apricot | +| | | | | | stones | +| | Bark | Wood | Outer | Inner | | +| | | | wood | wood | | +|________________________|_______|______|_______|_______|_________| +| | | | | | | +| In original substance | 16.7 | 19.6 | 18.2 | 20.7 | 18.4 | +| | | | | | | +| In residue from action | 6.53 | 8.6 | 4.9 | 6.4 | 7.0 | +| of 2.5 p.ct. HCl | | | | | | +|________________________|_______|______|_______|_______|_________| + +_Wood Gum._--The paper contains some observations on the various methods +of isolating this product. Attention is directed to the necessary +impurity of the product, and to the fact that the numbers for furfural +and for the xylose yielded by hydrolysis are considerably less than for +a pure pentosane. + +_Estimation of Cellulose._--The author investigated the process of Lange +and the 'celluloses' obtained from various raw materials. The products +from the woods of birch and maple contained furfural-yielding +constituents, represented by yields of 6-8 p.ct. furfural. Preference is +given to the process by comparison with others, at the same time that it +is recommended in all cases to examine the product for furfural +quantitatively, converting the numbers into pentosane equivalents, and +subtracting from the total 'cellulose' to give the true cellulose. + + +ZUR KENNTNISS DER MUTTERSUBSTANZEN DES HOLZGUMMI. + +E. WINTERSTEIN (Ztschr. Physiol. Chem., 1892, 381). + +~ON THE MOTHER SUBSTANCES OF WOOD-GUM.~ + +(p. 188) According to the text-books beech-wood may be regarded as the +typical raw material for the preparation of the laboratory product known +as wood-gum. The author has subjected beech-wood and beech-wood +cellulose (Schulze process) to a range of hydrolytic treatments, acid +and alkaline, in order to determine the conditions of selective action +upon the mother substance of the wood-gum. In the main it appears that +this group of furfuroids is equally resistant with the cellulose +constituents of the wood; in fact, that the mother substance of wood-gum +is a modified cellulose, and exists in the wood in chemical combination +with the 'incrusting substances.' + +Of the author's experimental results the following may be cited as +typical: + + Yield of furfural + Substance p.ct. +Original beech-wood 13.8 + +After boiling 3 hrs. with 1.25 p.ct. H_{2}SO_{4} (residue) 10.1 + + " " " " 5.0 " " " 5.6 + +Cellulose--isolated by Schulze process (yield 53 p.ct.) 6.9 + + " after further 14 days' digestion with the + Schulze acid (HNO_{3} + KClO_{3}) 5.9 + + " after extraction with 5 p.ct. NaOH in + cold (residue) 5.0 + + " after second extraction with 5 p.ct. NaOH + in cold (residue) 4.4 + + +UEBER DIE FRAGE NACH DEM URSPRUNG UNGESÄTTIGER VERBINDUNGEN IN DER +PFLANZE. + +C. F. CROSS, E. J. BEVAN, and C. SMITH (Berl. Ber., 1895, 1940). + +~ON THE SOURCE OF THE UNSATURATED COMPOUNDS OF THE PLANT.~ + +(p. 179) In distilling for furfural by the usual methods of boiling +cellulosic products with condensing acids, the furfural is accompanied +by volatile acids, also products of decomposition of the cellulosic +complex. A series of distillations was carried out with dilute sulphuric +acids of varying concentration from 10-50 H_{2}SO_{4} : 90-50 H_{2}O by +weight, using barley straw as a typical cellulosic material. The +distillates were collected in successive fractions, and the furfural and +volatile acid determined. The results are given in the form of curves. +The aggregate yields were as follows:-- + +Concentration of acid + (H_{2}SO_{4}) p.ct. 10 15 20 30 40 50 + +Furfural yield p.ct. of straw 2.0 2.0 4.4 10.1 11.5 11.0 + +Volatile acid (calculated + as acetic acid) p.ct. of straw 1.7 1.9 3.1 4.3 6.3 14.8 + +With acids up to 20 p.ct. H_{2}SO_{4} both products are formed +concurrently and in nearly equal quantity. With the 30 p.ct. acid there +is a great increase in the total furfural, and with the 40 p.ct. acid it +reaches nearly the maximum obtainable with HCl of 1.06 s.g. (Tollens), +in this case 12.4 p.ct. The volatile acid increases, but in less ratio; +it is also produced concurrently. With 50 p.ct. H_{2}SO_{4} the +conditions are changed. The total furfural is rapidly formed, whereas +the volatile acid continues to be formed long after the aldehyde ceases +to come over. Moreover, whereas in the previous cases it was mainly +acetic acid, it is now mainly formic acid. The method was then extended +to a typical series of celluloses, heated with the more concentrated +acid (40-50 p.ct. H_{2}SO_{4}), with the following results: + + __________________________________________________ +| | | | +| | | Volatile acid | +| | |_________________| +| | | | | +| | | Acetic | Formic | +|________________________|_______|________|________| +| | | | | +| Swedish filter-paper | 0.3 | 2.7 | 17.2 | +| Esparto cellulose | 12.4 | 3.2 | 16.6 | +| Bleached cotton | trace | 3.1 | 13.2 | +| Raw cotton (American) | -- | 5.0 | 9.4 | +| Jute cellulose | 5.2 | 4.9 | 22.7 | +| Beech (wood) cellulose | 6.4 | 3.5 14.6 | +|________________________|_______|________|________| + +The tendency in the hexoses and their polyanhydrides to split off one +carbon atom in the oxidised form, throws some light on the furfurane +type of condensation, which is represented in the lignocelluloses. We +are still without any evidence as to the possible transition of the +hexoses to benzenoid compounds. Such transitions would be more easily +explained on the assumption that the celluloses are composed in part of +polyanhydrides of the ketoses. + + +SPIRITUS AUS CELLULOSE UND HOLZ. + +E. SIMONSEN (Ztschr. angew. Chem., 1898, 3). + +~PRODUCTION OF ALCOHOL FROM CELLULOSE AND WOOD.~ + +(pp. 50, 209) This investigation was undertaken with one main object--to +determine the optimum conditions of treatment of wood-cellulose and of +wood itself for conversion into 'fermentable sugar.' The process of +'inversion' or hydrolysis, by digestion with dilute acid at high +temperature, involves the four main factors: pressure (i.e. +temperature), concentration of acid, ratio of liquid to cellulose and +duration of digestion. Each of these was varied in definite gradations, +and the effect measured. The degree of action was measured in terms of +'reducing sugar,' calculated from the results of estimation by Fehling +solution, as 'glucose' per cent. of original cellulose (or wood). + +(a) _Cellulose._ [Wood-cellulose obtained by bisulphite +process.]--With a proportion of total liquid to cellulose of 27 : 1, and +using sulphuric acid as the hydrolysing agent, the optimum results were +obtained with acids of 0.45-0.60 p.ct. (H_{2}SO_{4}) and pressures of +6-8 atm. The maximum yield of 'sugar' was 45 p.ct. of the cellulose. + +Under the above conditions the maximum of conversion is attained in 2 +hours. + +Having now regard to the production of a solution of maximum +_concentration_ of dissolved solids, the following conditions were +asertained to fulfil the requirement, and, in fact, may be regarded as +the economic optimum: + + Proportion of total liquid 6 times wt. of cellulose + Concentration of acid 0.5 p.ct. H_{2}SO_{4} + Pressure 10 atm. + Duration of digestion 1.5 hour + +giving a yield of 41 p.ct. 'reducing sugar' calculated to the original +cellulose (dry). + +_Alcoholic Fermentation of Neutralised Extract._--The liquors were found +to ferment freely, and on distillation to yield a quantity of alcohol +equal to 70 p.ct. of the theoretical--i.e. on the basis of the numbers +for copper oxide reduction. + +(b) _Hydrolytic 'Conversion' of Wood (Lignocellulose)._--A similarly +systematic investigation carried out upon pine sawdust established the +following as optimum conditions: + + Proportion of total liquid 5 times wt. of wood + Concentration of acid 0.5 p.ct. H_{2}SO_{4} + Pressure 9 atm. + Duration of digestion 15 minutes + +giving a yield of 20 p.ct. 'reducing sugar,' calculated from the +'Fehling' test. + +_Fermentation_ of the neutralised extracts gave variable results. The +highest yields obtained were 60 p.ct. of theoretical, the author finally +concluding that under properly controlled conditions of inversion and +fermentation 100 kg. wood yield 6.5 l. absolute alcohol. + + +ÜBER DIE URSACHE DER VON SIMONSEN BEOBACHTETEN UNVOLLSTÄNDIGKEIT DER +VERGÄHRUNG DER AUS HOLZ BEREITETEN ZUCKERFLÜSSIGKEITEN. + +B. TOLLENS (Ztschr. angew. Chem., 1898, 15). + +~ON THE CAUSE OF INCOMPLETE FERMENTATION OF SUGARS OBTAINED BY ACID +HYDROLYSIS OF WOOD.~ + +The author criticises Simonsen's explanation of the results obtained +with extracts from pine wood. The incompleteness of fermentation of the +products is certainly due in part to the presence of furfural-yielding +carbohydrates, which are resistant to yeast. The pine woods contain 8-10 +p.ct. of these constituents in their anhydride form ('pentosanes'). They +yield readily to acid hydrolysis, and certainly constitute a +considerable percentage of the dissolved products. A similar complex was +obtained by the author in his investigation of peat (Berl. Ber. 30, +2571), and was found to be similarly incompletely attacked by yeast. The +yields of alcohol corresponded with the proportion of the total +carbohydrates disappearing. These were the hexose constituents of the +hydrolysed complex, the pentoses (or 'furfuroids') surviving intact. + + +UEBER SULFITCELLULOSEABLAUGE. + +H. SEIDEL (Ztschr. angew. Chem., 1900). + +~WASTE LIQUORS FROM BISULPHITE PROCESS.~ + +(p. 210) Later researches confirm the conclusion that in the soluble +by-products of these cellulose processes the S is combined as a SO_{3}H +group. The following analyses of the isolated lignin sulphonic acid are +cited: + + ________________________________________________ +| | | | | +| | C | H | S | +|__________________________|_______|______|______| +| | | | | +| (a) Lindsey and Tollens | 56.12 | 5.30 | 5.65 | +| (b) Seidel (1) | 56.27 | 5.87 | 5.52 | +| (c) Seidel and Hanak (2) | 53.69 | 5.22 | 8.80 | +| (d) Street | 50.22 | 5.64 | 7.67 | +|__________________________|_______|______|______| + +The variations are due to the varying conditions of the digestion of the +wood and to corresponding degrees of sulphonation of the original +lignone group. Calculating the composition of the latter from the above +numbers on the assumption that the S represents SO_{3}H, the following +figures result: + + __________________________________ +| | | | | +| | (a) and (b) | (c) | (d) | +|___|_____________|_______|_______| +| | | | | +| C | 64.00 | 65.1 | 59.61 | +| H | 6.65 | 6.33 | 6.69 | +|___|_____________|_______|_______| + +This author considers that beyond the empirical facts established by the +above named[10] very little is yet known in regard to the constitution +of the lignone complex. + +Nor is there any satisfactory application of this by-product as yet +evolved. Evaporation and combustion involve large losses of sulphur +[D.R.P. 74,030, 83,438; Seidel and Hanak, Mitt. Techn. Gew. Mus. 1898]. +A more complete regeneration of the sulphur has been the subject of a +series of patents [D.R.P. 40,308, 69,892, 71,942, 78,306, 81,338], but +the processes are inefficient through neglect of the actual state of +combination of the S, viz. as an organic sulphonate. The process of V.B. +Drewson (D.R.P. 67,889) consists in heating with lime under pressure, +yielding calcium monosulphite (with sulphate and the lignone complex in +insoluble form). The sulphite is redissolved as bisulphite by treatment +with sulphurous acid. This process is relatively costly, and yields +necessarily an impure lye. It has been proposed to employ the product as +a foodstuff both in its original form and in the form of benzoate +(D.R.P. 97,935); but its unsuitability is obvious from its composition. +A method of destructive distillation has been patented (D.R.P. 45,951). +The author has investigated the process, and finds that the yield of +useful products is much too low for its economical development. Fusion +with alkaline hydrates for the production of oxalic acid (D.R.P. 52,491) +is also excluded by the low yield of the product. + +The application of the liquor for tanning purposes (D.R.P. 72,161) +appears promising from the fact that 28 p.ct. of the dry residue is +removed by digestion with hide powder. This application has been +extensively investigated, but without practical success. Various +probable uses are suggested by the viscosity of the evaporated extract. +As a substitute for glue in joinery work, bookbinding, &c., it has +proved of little value. It is applied to some extent as a binding +material in the manufacture of briquettes, also as a substitute for +gelatin in the petroleum industry. Cross and Bevan (E.P. 1548/1883) and +Mitscherlich (D.R.P. 93,944 and 93,945) precipitate a compound of the +lignone complex and gelatin by adding a solution of the latter to the +liquors. The compound is redissolved in weak alkaline solutions and +employed in this form for engine-sizing papers. Ekman has patented a +process (D.R.P. 81,643) for 'salting out' the lignone sulphonates, the +product being resoluble in water and the solution having some of the +properties of a solution of dextrin. Owing to its active chemical +properties this product--'dextron'--has a limited capability of +substituting dextrin. The suggestion to employ the evaporated extract as +a reducing agent in indigo dyeing and printing has also proved +unfruitful. The author's application of the soda salt of the lignone +sulphonic acid as a reducing agent in chrome-mordanting wool and woollen +goods (D.R.P. 99,682) is more successful in practice, and its industrial +development shows satisfactory progress. The product is known as +'lignorosin.' + +FOOTNOTES: + +[10] See more particularly: Lindsey and Tollens, _Annalen_, 267, 341; +Cross and Bevan's _Cellulose_, pp. 197-203; Street, Inaug.-Diss., +Göttingen, 1892; Klason, _Rep. d. Chem. Ztg._ 1897, 261; Seidel and +Hanak, _Mitt. d. Techn. Gew. Mus._ 1897-1898. + + + + +SECTION VII. PECTIC GROUP + + +UNTERSUCHUNGEN ÜBER PECTINSTOFFE. + +R. W. TROMP DE HAAS and B. TOLLENS (Lieb. Ann., 286, 278). + +ÜBER DIE CONSTITUTION DER PECTINSTOFFE, B. TOLLENS (ibid. 292). + +~INVESTIGATIONS OF PECTINS.~ + +(p. 216) It is generally held that the pectins are, or contain, oxidised +derivatives of the carbohydrates. The authors have isolated and analysed +a series of these products, and the results fail to confirm a high +ratio O : H. The following are the analytical numbers: + + ________________________________________________ +| | | | | | +| Pectin from | Ash | C | H | Ratio H : O | +|______________|______|______|_____|_____________| +| | | | | | +| Apple | 6.2 | 43.4 | 6.4 | 1 : 7.9 | +| Cherry | 20.5 | 42.5 | 6.5 | 1 : 7.9 | +| Rhubarb | 4.2 | 43.3 | 6.8 | 1 : 7.4 | +| Currant | 5.0 | 47.1 | 5.9 | 1 : 8.5 | +| Greengage | 3.3 | 43.0 | 5.9 | 1 : 8.5 | +| Turnip | 7.3 | 41.0 | 5.9 | 1 : 9.0 | +|______________|______|______|_____|_____________| + +Acid hydrolysis (4 p.ct. H_{2}SO_{4}) gave syrupy products not +crystallisable--in certain cases the hydrolysis was accompanied by +separation of insoluble cellulose. The insoluble product from currant +pectin had the composition C 54.4, H 5.0. + +Tollens points out that the results of empirical analysis are +inconclusive; and that from the acid reactions of these products and +their combination with bases, carboxylic groups are present, though +probably in anhydride or ester form. + +The pectins may be regarded as closely related to the mucilages +(_Pflanzenschleim_), differing from them only by the presence of the +oxidised groups in question. + + +UEBER DIE CONSTITUTION DER PECTINSTOFFE. + +C. F. CROSS (Berl. Ber., 1895, 2609). + +~CONSTITUTION OF PECTINS.~ + +It is pointed out that the composition of the pectin of white currants, +as given in the preceding paper, is that of the typical lignocellulose, +the jute fibre. The product was isolated and further investigated by the +author. It gave 9.8 p.ct. furfural on boiling with HCl (1.06 s.g.), +reacted freely with chlorine, giving quinone chlorides, and with ferric +ferricyanide to form Prussian blue. This 'pectin' is therefore a form +of soluble lignocellulose. The 'pectic' group consequently must be +extended to include hydrated and soluble forms of the mixed complex of +condensed and unsaturated groups with normal carbohydrates, such as +constitute the fibrous lignocelluloses. + + +UEBER DAS PFLANZLICHE AMYLOID. + +E. WINTERSTEIN (Ztschr. Physiol. Chem., 1892, 353). + +~ON VEGETABLE AMYLOID.~ + +(p. 224) A group of constituents of many seeds, distinguished by giving +slimy or ropy 'solutions' under the action of boiling water are +designated 'amyloid.' They are reserve materials, and in this, as in the +physical properties of their 'solutions,' they are very similar to +starch. They are, however, not affected by diastase; and generally are +more resistant to hydrolysis. Typical amyloids have been isolated by the +author from seeds of _Tropoeolum majus, Poeonia officinalis_, and +_Impatiens Balsamina_. The raw material was carefully purified by +exhaustive treatment with ether and alcohol, &c.; the amyloid then +extracted by boiling with water, and isolated by precipitation with +alcohol. Elementary analysis gave the numbers C 43.2, H 6.1. On boiling +with 12 p.ct. HCl it gave 15.3 p.ct. furfural; oxidised with nitric acid +it yielded 10.4 p.ct. mucic acid. Specimens from the two first-named raw +materials gave almost identical numbers. + +_Hydrolysis._--On boiling with dilute acids these products are gradually +broken down, dissolving without residue. In this respect they are +differentiated from the mucilages, which give a residue of cellulose +(insoluble). From the solution the author isolated crystalline +galactose, but failed to isolate a pentose. Dextrose was also not +identified directly. + +The tissue residues left after extracting the amyloid constituent, as +above described, were subjected to acid hydrolysis. A complex of +products was obtained, from which galactose was isolated. A +furfural-yielding carbohydrate was also present in some quantity, but +could not be isolated. The original seed tissues, therefore, contain an +amyloid and a hemicellulose, the latter differentiated in its resistance +to water. Both yield, however, to acid hydrolysis a complex of products +of similar composition and constitution. + + +UEBER DEN GEHALT DES TORFES AN PENTOSANEN ODER FURFUROLGEBENDEN STOFFEN +UND AN ANDEREN KOHLENHYDRATEN. + +H. V. FEILITZEN and B. TOLLENS (Berl. Ber., 1897, 2,571). + +~CARBOHYDRATE CONSTITUENTS OF PEAT.~ + +(p. 240) An investigation of typical peats taken at successive depths +showed increasing percentage of carbon, and inversely a decreasing yield +of furfural. The numbers may be compared with those for _Sphagnum +cuspidatum_--with C = 49.80 p.ct., and furfural 7.99 p.ct., calculated +to dry, ash-free substance: + + __________________________________________________ +| | | | +| Depth at which taken | C p.ct. | Furfural p.ct. | +|_______________________|_________|________________| +| _ | | | +| | 20-100 cm. | 51.08 | 6.93 | +| I. | 100-200 " | 53.52 | 5.30 | +| |_ 200-300 " | 58.66 | 3.19 | +| _ | | | +| | Surface-20 " | 55.47 | 3.40 | +| II. | 20-60 " | 55.06 | 3.48 | +| | 60-100 " | 58.25 | 1.45 | +| | 100-120 " | 58.23 | 1.19 | +| |_ 180-200 " | 57.57 | 1.80 | +|_______________________|_________|________________| + +_Cellulose_ was estimated by the Lange method. The yield from _Sphagnum_ +was 21.1 p.ct. + +From specimen I. at { 20-100 cm. 15.20 + { 100-200 " 6.87 + +From the peat of lower depths no cellulose could be obtained. + +_Hydrolysis_ (acid).--On heating with 1 p.ct. H_{2}SO_{4} at 130-135°, +soluble carbohydrates were obtained, amongst which mannose was +identified, and galactose shown to be present in some quantity. After +fermenting away the hexoses, the residue was treated with +phenylhydrazine and an osazone separated. It contained 17.3 p.ct. N, but +melted at 130°. The substance could not be identified as an osazone of +any of the yet known pentoses. + + + + +SECTION VIII. INDUSTRIAL AND TECHNICAL. GENERAL REVIEW + + +~The Industrial Uses of Cellulose.~ + +C. F. CROSS (Cantor Lectures, Soc. of Arts, 1897). + +(p. 273) A series of three lectures, in which the more important +industries in cellulose and its derivatives are dealt with on their +scientific foundations, and by means of a selection of typical problems. +In reference to textiles, the small number of vegetable fibres actually +available, out of the endless variety afforded by the plant world, is +referred to the number of conditions required to be fulfilled by the +individual fibre, thus: yield per cent. of harvested weight or per unit +of field area, ease of extraction, the absolute dimensions of the +spinning unit, and the proportion of variation from the mean dimensions; +the relative facility with which the unit fibre can be isolated +preparatory to the final twisting operation; the chemical constants of +the fibre substance, especially the percentage of cellulose and degree +of resistance to hydrolysis. It is suggested that any important addition +to the very limited number fulfilling the conditions, or any great +improvement in these, can only result from very elaborate artificial +selection and cultural developments on this basis. + +The paper making fibres are shown to fall into a scheme of +classification based on chemical constitution, and consisting of the +four groups: (a) Cotton [flax, hemp, rhea], (b) wood celluloses, +(c) esparto, straw, and (d) lignocelluloses. Papers being exposed to +the natural disintegrating agencies, more especially oxygen, water (and +hydrolysing agents generally), and micro-organisms, the relative +resistance of the above groups of raw materials is discussed as an +important condition of value. The indirect influence of the ordinary +sizing and 'filling' materials is discussed. The paper-making quality of +the fibrous raw materials is also discussed, not merely from the point +of view of the form and dimensions of the ultimate fibres, but their +capacity for 'colloidal hydration.' This is complementary to the action +of rosin, i.e. resin acids, in the engine-sizing of papers; and the +proof of the potency of this factor is seen in the superior effects +obtained in sizing jointly with solutions of cellulose and, more +particularly, viscose and rosin. Wurster's much-cited monograph of the +subject of rosin-sizing ['Le Collage des Papiers,' Bull. Mulhouse, 1878] +neglects to take into consideration the contribution of the cellulose +hydrates to the total and complex sizing effect, and hence gives a +partial view only of the function of the resin acids. + +In further illustration of fundamental principles various developments +in the textile industries are discussed, e.g. the bleaching of jute, +cotton, and flax, and special developments in the spinning of rhea and +flax. + +The concluding lecture deals with later progress in the industrial +applications of cellulose derivatives, chiefly the sulphocarbonate +(viscose); the nitrates, in their applications to explosives, on the one +hand, and the spinning of artificial fibres (lustra-cellulose), on the +other; and the cellulose acetates. + + +~La Viscose et le Viscoide.~ + +C. H. BARDY (Bull. Soc. d'Enc. Ind. Nationale, 1900, March). + +This is a report presented to the Committee of Economic Arts of the +above Society, dealing with the industrial progress in products obtained +by means of the sulphocarbonate of cellulose (viscose). + +The following developments are noted: + +_Engine-sized Papers._--The viscose, by coating the fibres with +regenerated cellulose hydrate, adds very much to the tensile strength of +papers. Increase of 40-60 p.ct. is attainable by addition of cellulose +in this form from 1-4 p.ct. on the weight of the paper. + +_Viscoid._--Solid aggregates are formed by incorporating viscose with +mineral matters, hydrocarbons, &c. Products are cast or moulded into +convenient forms, and, after purification and sufficient ageing, are +available for various structural uses. + +_Paint._--The viscose is used as a vehicle for pigments, the mixture +being used either as a paint or for coating papers with fine surfaces, +such as required in the reproduction of photo-blocks. In these +applications the extraordinary viscosity of the product conditions the +economic use of the cellulose in competition with oils, on the one hand, +and organic colloids, such as gelatine, casein, &c., on the other. + +By suitable alteration of the formula for making the paint a product is +obtained which has an extraordinary power of removing paint from old +painted surfaces. The product has been officially adopted by the French +Admiralty, and receives extensive application in removing the paint from +ships. + +_Films._--Films are produced from the viscose itself in various ways. +Plane or flat by solidifying the viscose on glass surfaces, removing the +by-products and rolling the films. The film is also produced by +applying the viscose on textile fabrics, drying down, and fixing on a +stenter machine, then washing away the alkaline by-products from the +fixed film. A large number of industrial effects are obtained by +suitably varying the mixtures applied. + +_Cellulose-indiarubber._--The viscose, in its concentrated form, can be +incorporated with rubber-hydrocarbon mixtures, and these mixtures can be +used both as water-proofing films, as applied to textiles, or can be +solidified into the class of goods known as 'mechanicals.' The cellulose +not only cheapens the mixture, but produces new technical effects. + +_Spinning._--The viscose is spun by special methods, patented by C. H. +Stearn. As produced in thread form, the diameters are approximately +those of natural silk. In commercial form it is a multiple thread (of 15 +or more units) at from 50-200 deniers on the silk counts. It is a thread +of high lustre, and more nearly approaches the normal cellulose in +chemical properties than any of the other artificial silks. It can also +be spun in threads of very much larger diameter, which can be used as a +substitute for horsehair, for carbonising for incandescent electric +lamps, &c. + +_Cellulose Esters._--These are conveniently made from cellulose, +regenerated from the solution as sulphocarbonate. The tetracetate is +made from this product on the industrial scale. Nitrates are +conveniently made by treatment with the ordinary mixed acids. For fuller +details the original report may be consulted. + + +VISKOS. + +R. W. STREHLENERT (Svensk Kemisk Tidskrift, Stockholm, 1900, p. 185). + +A report on the industrial development of viscose, covering essentially +the same ground as the above. + + +~Ueber die Viscose.~ + +B. M. MARGOSCHES (Reprint from Zeitschrift für die gesammte +Textil-Industrie, 1900-01, Nos. 14-20).[11] + + +~Report of Committee on the Deterioration of Paper.~ + +(Soc. of Arts, 1898.) + +(p. 304) The Report of a Representative Committee appointed by the +Society of Arts to inquire into the question of qualities of book papers +in relation to their several applications, and more especially for +documents of permanent value. + +The report first discusses the two directions of depreciation of papers +in use: (1) Actual disintegration shown by loss of resistance to +fracture by simple strain, and by loss of elasticity--i.e. increase of +brittleness; (2) discolouration. These are independent effects, but +often concurrent. They are the result of chemical changes of the +cellulose basis of the paper, brought about by acids or oxidants used in +the process of manufacture, and not completely removed from the pulp, or +by acid products of bleaching--e.g. oxycelluloses or chlorinated +derivatives; again, by the changes of starch used as a 'sizing' agent, +or by oxidations induced by rosin constituents when the rosin is used in +excess. Discolouration is an attendant phenomenon of these changes, but +is more frequently due to the presence of the lower-grade celluloses +(esparto and straw) and the lignocelluloses (mechanical wood-pulp). + +The physical and chemical qualities of papers depending primarily upon +their fibrous or pulp basis, and in a secondary degree upon the kind and +proportion of the constituents added for the purpose of filling and +'sizing,' the report concludes with the following recommendations, +positive and negative, under these heads: + +The Committee find that the practical evidence as to permanence fully +confirms the classification given in the Cantor Lectures on 'Cellulose,' +1897 [J. Soc. Arts, xlv. 690-696], and which ranges the paper-making +fibres in four classes: + +(A) Cotton, flax, and hemp (rhea). + +(B) Wood celluloses, (a) sulphite process and (b) soda and +'sulphate' process. + +(C) Esparto and straw celluloses. + +(D) Mechanical wood-pulp. + +In regard, therefore, to papers for books and documents of permanent +value, the selection must be taken in this order, and always with due +regard to the fulfilment of the conditions of normal treatment above +dealt with as common to all papers. + +The Committee have been desirous of bringing their investigations to a +practical conclusion in specific terms--viz. by the suggestion of +standards of quality. It is evident that in the majority of cases there +is little fault to find with the practical adjustments which rule the +trade. They are, therefore, satisfied to limit their specific findings +to the following--viz. (1) normal standard of quality for book-papers +required for publications of permanent value. For such papers they +specify as follows: + +Fibres: Not less than 70 p.ct of fibres of class A; class D excluded. + +Sizing: Not more than 2 p.ct. rosin, and finished with the normal +acidity of pure alum; starch excluded. + +Loading: Not more than 10 p.ct. total mineral matter (ash). + +(2) With regard to written documents, it must be evident that the proper +materials are those of class A, and that the paper should be pure and +sized with gelatin, and not with rosin. All imitations of high-class +writing-papers which are, in fact, merely disguised printing-papers, +should be carefully avoided. + +_Appendix._--To the Report is added 'Abstracts of Papers' in +'Mittheilungen aus den Koniglichen Technischen Versuchsanstalten, +Berlin,' for the years 1885-1896 inclusive--which is, in fact, a summary +of the investigations of the Institution in connection with paper and +paper-standards. + + * * * * * + +(p. 273) ~Special Industrial Developments.~--From the point of view of the +chemist there has been a very large development of the cellulose +industries during the last five years. This is not so much marked by the +gradual and progressive growth of the well-established industries, as by +the success of the newer ones, with the attendant forecast of enormous +developments of the industries in artificial products, the manufacture +of which rests upon a purely chemical basis. We can, of course, only +treat them from this limited standpoint, and so far as they involve and +elucidate chemical principles. + + +~I. Chemical Treatments of Raw Materials.~ + +(a) ~Flax-spinning.~--The treatment of the roving on the spinning-frame +by the addition of reagents to the macerating liquid--otherwise and +usually hot water--continues to be justified by results. The technical +basis of the process and the reactions determined in the spinning-trough +by the alkaline salts used--chiefly sulphite and phosphate of soda--is +set forth in the original work, p. 280. Since that time a sufficient +period has elapsed to judge the effects, both technical and industrial, +by the results of a commercial undertaking based on the exclusive use of +the process. Such a concern is the Irish Flax Spinning Company of +Belfast. At this mill the experience is uniform and fully established +that by means of the process the drawing, i.e. spinning, quality of +inferior flaxes is very considerably appreciated, enabling the spinner +to use such flaxes for yarns of fineness which are unattainable by the +ordinary method of spinning through hot water. Notwithstanding the +success of this undertaking the development of the method is still +inconsiderable. It is none the less a further and forcible demonstration +of the existence of margins of increased technical effect which it is +the work of the scientific technologist to exploit. + +(b) ~Wood-pulp and Methods of Manufacture.~--There is a steady growth in +the consumption of wood-pulps (cellulose) relatively to other materials. +In regard to the paper-trade of the world, this continues to be one of +the most prominent characteristics of its evolution. In the United +Kingdom the conditions of its competition are of a more special kind by +reason of the firm foothold of esparto, which is a most important staple +in the manufacture of fine printings. Whereas the consumption of esparto +remains nearly stationary at about 200,000 tons per annum, the +importation of wood-pulps has shown the extraordinary rate of increase +of doubling itself every five years. But in the group 'wood-pulps' the +trade returns have until recently included the 'mechanical' or ground +wood-pulps. From 1898 we have separate returns for the chemical or +cellulose pulps, and in 1899 the tonnage reached nearly to that of +esparto, with a total money value about 80 p.ct. greater. When it is +remembered that this is one of the newer chemical industries in +cellulose products, and that these large commercial results have been +accomplished during a period of twenty years, we are impressed with the +scope of the industrial outlook to the chemist, afforded by the arts of +which cellulose is the foundation. + +It may be noted that there have been no important developments in the +purely chemical processes involved in the several systems of preparing +cellulose from wood. The acid methods (bisulphite processes) have +developed much more extensively than the alkaline, the latter including +the caustic soda and the mixed sulphide ('Dahl') process. The bisulphite +processes depended in the earlier stages upon the efficiency of +lead-lined digesters. But the problem of acid-resisting linings has been +much more perfectly solved in later years in the various types of cement +and other silicate linings now in use. The relative permanency of these +linings has had an important effect on the costs of production. Further +economies result from the use of digesters of enormous capacity, dealing +with as much as 100 tons of wood at one operation. As a combined result +of economic production and active competition, the selling prices of +'sulphite pulp' have moved steadily downwards in relation to other +half-stuffs and raw materials. As a necessary consequence the prices of +those which it has gradually displaced have depreciated, and a study of +the price and tonnage-equilibrium as between rags, esparto, and +wood-pulp over a series of years forms an interesting object-lesson in +the struggle for survival which is an especial mark of modern industry. +For these matters the reader is referred to the special literature of +the paper-making industry.[12] + +It is not a little remarkable that the main by-product of these +bisulphite processes--the sulphonated derivatives of the lignone +constituents of the wood--is still for the most part an absolute waste, +notwithstanding the many investigations of technologists and attempts to +convert it to industrial use (see p. 149). Seeing that it represents a +percentage on the wood pulped equal to that of the cellulose obtained, +it is a waste of potentially valuable material which can only be termed +colossal. Moreover, as a waste to be discharged into water-courses, it +becomes a source of burden and expense to the manufacturer, and with the +increasing restrictions on the pollution of rivers it is in many +localities a difficulty to be reckoned with only by the cessation of the +industry. The problem in such cases becomes that of dealing with it +destructively, i.e. by evaporation and burning. In this treatment the +obviously high calorific value of the dissolved organic matter (lignone) +appears on the 'credit' side. But where calcium and magnesium +bisulphites are used, the residue from calcination is practically +without value. It appears, however, that by substituting soda as the +base the alkali is recoverable in such a form as to be directly +available for the alkaline-sulphide or 'Dahl' process. As a more +complicated alternative the soda admits of being recovered on the lines +of the old black-ash or Leblanc process, and the sulphur by the now +well-established 'Chance' process, for which, of course, an addition of +lime is necessary to the fully evaporated liquors previously to +calcining. The engineering features of the system, so far as regards +evaporating and calcining, are the same. For economic working there is +required (a) evaporation by multiple effect and (b) calcining on the +continuous rotary principle. For the latter a special modification has +been devised so that the draught of air is concurrent with the movement +of the charge in the furnace, securing a progressively increasing +temperature within the furnace. This interesting development of the +chemical engineering of wood-pulp systems has been elaborated by two +well-known technologists, Drewson and Dorenfeldt, and readers who wish +to inform themselves in detail of these developments are referred to the +various publications of these inventors. + +Assuming the present necessity of a destructive treatment of the +by-products of the bisulphite processes, the scheme has many advantages. +The soda-bisulphite liquors are more economically prepared; the pulp +obtained is superior in paper-making quality to that resulting from the +lime or magnesia (bisulphite) processes: it is more economically +bleached. + +Then, as pointed out, the soda may on the one plan be obtained in a form +in which it is immediately available as a powerful hydrolysing alkali in +the manufacture of a 'soda' pulp. These two systems become, therefore, +in a new sense complementary to one another. Lastly, it is obvious that +the employment of soda as the base opens out a new vista for developing +the electrolytic processes of decomposing common salt. + +The authors have assisted in preparing plans for a comprehensive +industrial scheme combining all these more modern developments. In this +scheme it is only the combination which is novel, and as it involves no +new principles in the chemical treatments of the materials we are not +further concerned with it than to have briefly sketched its economic +basis. This may be summed up in result in the important question of cost +and selling price, and the estimate is well grounded that by means of +this scheme _bleached wood-pulp_ can be sold on the English market at +10l. a ton. It is important to note this figure and to compare it with +the prices of twenty years ago. The fall has been continuous, +notwithstanding the influence of the opposing factors of increasing +consumption, exhaustion of accessible supply of timber, and relative +appreciation of the essential costs of steam, chemicals, and labour. It +is important in forecasting the future, since the youngest and +apparently most promising of the 'artificial' cellulose industries +employs wood-cellulose by preference as its raw material (see p. 173). + +As a last point it must be considered that as chemists we are bound to +anticipate the realisation of value in the soluble by-products of the +bisulphite processes. Outside the intrinsic interest attaching to the +solution of this problem, it carries with it the promise of a further +economy in the production of wood-cellulose. + +~Bleaching of Vegetable Textiles.~--By far the largest of these industries +are those which are engaged in producing the 'pure white' on cotton and +flax goods. The process, considered chemically, is simply that of +isolating a pure cellulose, and we endeavoured to give due prominence to +this view in the original work. It is important to insist upon it for +the reason that this view gives the due proportion of chemical value to +the several contributory treatments--alkaline hydrolyses (caustic lime +and soda boils), hypochlorite oxidations, and incidental acid treatments +(souring). The first of these is by far the largest contributor of +'chemical work,' though the second, by being the agent for the actual +whitening effect or bleaching action proper, occupies a position of +often exaggerated importance. + +In bleaching processes there has been no radical change of system on the +large scale since the introduction of the 'Mather' kier in 1885, and the +associated change from lime and ash boiling to the caustic soda +circulating boil with reduced volume of lye, which this mechanical +device rendered practicable. It is outside the scope of this work to +follow up this branch of technology in any detail, and we cannot discuss +the evolution of systems on variations of detail where no essential +principle is involved. But we have to notice a very recent development +which has only just begun its industrial career, and which does give +effect to a principle of treatment not previously applied. This is +tersely stated by its originator, William Mather,[13] in the +expression, 'it is more economical to make liquids pass through cloth +than to make cloth pass through liquids.' The starting point of this +development is the invention of a complete self-contained machine in +which a rolled batch of cloth can receive a succession of chemical +treatments, with accessory washings--the solutions, or wash waters, +being circulated through the cloth. The essential fact on which this +system is based is that a perfect liquid circulation can be maintained +from selvedge to selvedge through the folds of a tightly rolled batch of +cloth. Such circulation is therefore quite independent of the diameter +of the batch. If we consider a cloth under chemical treatment with +solutions, it is clear that the reactions and interchanges of soluble +matters within the cloth, within the twisted elements of the yarn, and +in the last grade of distribution within the actual ultimate fibres, are +subject to capillary transmission, and osmotic exchange. There is a +mixture of these molecular effects, with the circulation in mass, +sweeping both faces of the cloth. It is obvious that for the mass effect +a relatively very small volume of circulating liquid is necessary to +maintain uniform conditions of action. In the actual disposition of the +machine the rolled batch of cloth nearly fills the cylindrical space of +what we may call the reaction chamber, and the circulation of the liquid +is maintained by a circulating pump and a differential pressure in the +horizontal plane across and through the folds of the batch. This is in +the meantime kept in slow revolution. For a full description of these +mechanical details the reader is referred to the original patent +specifications [Engl. Pat. 23,400, 23,401; 1900, W. Mather]. If we again +consider the principles involved, they are very much as set forth in +our original work (pp. 288-291). Boiling processes in which a +relatively large volume of liquid is used are wasteful of steam, the +active agent is unnecessarily diluted or used in superfluous quantity, +and the soluble by-products, being continually removed as formed, cannot +so effectively contribute by secondary actions to the chemical work. The +new mechanical appliance enables us to further reduce the volume of +liquid required in the alkaline-hydrolytic treatment of vegetable +textiles, and where advantageous to bring the treatment down (or up) to +a process of steaming with the active agent dissolved in a minimum +proportion of water relative to the cloth. This concentration of effect +is of importance in flax cloth, and especially linen treatment, where +the peculiarly resistant cutocelluloses have to be attacked and a +considerable proportion of waxy by-products to be removed. These points +are the basis of the special process of Cross and Parkes [Engl. Pat. +25,076/ 99] for steaming flax (and cotton) goods with an emulsion +containing, in addition to the special hydrolysing agent--caustic +soda--mixtures of soap with 'mineral' or other oils, the presence of +which effectually aids the removal of the by-products in question. + +A complete system on these lines is now working on the industrial scale +in the Belfast district. The results are not merely economical in +largely reducing the number of alkaline boiling treatments required on +the old plan of pan or 'pot' boiling, but are visible in the strength +and finish of the linens so treated. + +For cotton bleaching the costs may be put down at a fraction of those of +the Irish linen bleach. The economical advantages of the new system are +obviously less in relation to the lesser total costs. But there are +other points which have come into more prominent influence. The +mechanical wear and tear on the cloth is considerable in the ordinary +process, more especially in the mangle-washes. As a result the +adjustment of warp and weft is more or less disturbed. These defects are +absent from a system which operates on the cloth in a fixed position. + +But as we are mainly concerned with the purely chemical factors we +cannot pretend to deal with textile questions. We have to notice the +remaining element of chemical economy as it involves a fundamental +principle. The practice of washing residues or products of reaction free +from reagents and soluble by-products involves a well-known mathematical +law, under which the rate of purification is a function rather of the +_number_ of successive changes of washing liquid than of the volume of +the latter. The ordinary practice of textile washings entirely ignores +this principle, and the consumption of water in consequence may reach +many thousand times the economic minimum. With supplies of water often +in indefinite excess of requirements, even in this most wasteful method, +bleachers are in no need to consider the question of consumption. But +leaving aside particular and local considerations of advantage the fact +is that the new system gives control of the practice of washing, +enabling the operator to adapt an important element of the daily routine +to a fundamental principle which has been almost universally ignored. + +In the oxidising processes which follow the alkaline treatments, the +hypochlorites are still the staple agents. Owing to the steady relative +fall in the selling prices of the permanganates these are coming into +more extensive use, but the consumption is still small, and they are +mainly used for certain special effects, chiefly in linen or more +generally flax cloth bleaching. + +~Paper-pulp Spinning.~--Paper is a continuous web or fabric produced by +the interlocking of the structural fibrous units of the well-known short +length. In Japan and other countries paper is made to serve for all or +some of the purposes for which we employ string or twine, and to give +the necessary tensile strength the paper is twisted or rolled on itself. +Such twisting, however, adds nothing to the intrinsic tensile qualities +of the original paper. + +A new technical effect is realised in this direction by the treatment of +paper-pulp in the process of its conversion into a continuous web: The +pulp is formed into continuous strips of convenient breadth (usually +from 2 to 8 mm.), these receive a 'rolling-up' treatment immediately +following the squeeze of the press rolls by which the superfluous water +is removed: they are then further but incompletely dried, and in this +condition are subjected to a final spinning or twisting treatment on +ring-spinning machinery of special construction. + +Such a process was originally patented by C. Kellner in this country +(E.P. No. 20,225/1891), and is fully described in his specification. +Later improvements in detail were patented by G. Türk (E.P. 4621/1892). + +A joint system is now being industrially developed in Germany by the +Altdamm-Stahlhammer Pulp and Paper Company under the technical direction +of Dr. Max Müller, and there appears to be every prospect of the product +taking a position as a staple textile. + +The process has only the incidental interest in connection with our main +subject, that it employs chiefly the 'chemical' pulps or celluloses as +raw materials. The industrial future of the application must, of course, +be largely determined by costs of production, as the directions of +application in the weaving industries will be limited by the necessarily +inferior grade of tensile strength belonging to these products and the +degree by which this is lowered on complete wetting. All these questions +have been duly weighed by those engaged in this interesting development, +and the conclusion of those qualified to judge is that the new industry +has vindicated for itself a permanent position. + +~II. The Chemical Derivatives of Cellulose~, in their industrial aspects, +have come to occupy a profoundly important position in the world's +affairs. In the way of any essential alteration of the perspective from +that obtaining in 1895 we have nothing to chronicle. No new derivatives +of industrial importance have been added in that period; but certain new +methods incidental to the preparation of well-known compounds or for +converting them into more generally available forms have been +introduced, and these are contributing to the rapid expansion of the +'artificial' cellulose industries. + +Of the cellulose esters the nitrates are still the only group in +industrial use. There uses for explosives have attained immense +proportions, and their applications for structural purposes are +continually on the increase. The manufacture of smokeless powders on the +one hand, and of celluloid and xylonite (both in the form of films and +solid aggregates) on the other, has taken no new departure. The industry +in 'artificial silks' or 'lustra-celluloses,' by the collodion processes +also, whilst presenting features of unusual interest attaching to rapid +expansion, has been barren of contribution of fundamental scientific or +technical importance. The tetracetate is now manufactured on the large +scale, but the product has yet to make its market. + +The process of mercerising cotton yarns and cloth has been developed to +an industry of colossal dimensions, and the growth has been especially +rapid during the last five years. Significant of the technical progress +in these two industries, with their common aim of appreciating cellulose +in the scale of textiles by approximating its external properties in +those of silk, is the appearance of a monograph of the technology of +each, notices of which have been previously given (pp. 22-26). + +There is little doubt, however, that the question of the future +industry in the various forms of cellulose, thread, film, structureless +powder or solid aggregate, obtainable by artificial means, mainly turns +upon cost of production. Irrespective of cost, there would, no doubt, be +a market for all these products, based upon such of their properties or +effects as are indispensable and not otherwise obtainable. As an +illustration, we may cite the extraordinary selling prices of 40-50 fr. +per kilo, for the 'artificial silks' (collodion process) which ruled +some three years ago; and we may note that for a special application of +viscose the dissolved cellulose is paid for at the rate of 10 per +lb. These facts are certainly worthy of mention, and should be borne in +mind as an index of some special features of modern manufacturing +industry. But with a material like cellulose rendered available in a new +shape the question which always arises more prominently than that of +limited uses at high prices is that of consumption on the extensive +scale which marks the older and well-known products. That question is +rapidly solving itself in this country as regards the 'artificial +silks.' There is at present a limited market at 9s.-10s. per lb., a +price which on the one side excludes extensive consumption, and on the +other practically bars manufacture in this country by any of the +collodion systems. It will appear from a very elementary calculation of +what we may call the theoretical costs that the above selling price +would not have a remunerative margin. The theoretical costs are made up +of + +Raw materials[14] {Cotton. Nitrating acid. Ether-alcohol (solvent). + {Denitrating chemicals. + + {(a) Nitrating and preparing collodion. Denitrating + { and bleaching. +Labour {(b) Textile operations. Spinning. Winding and twisting. + {Rewinding. + +Power {Making, filtering, and distributing collodion. + {Driving textile machinery. + +Added to which are the costs of expert management and supervision and +general establishment expenses. It is evident that raw materials make up +a large fraction of the total cost; also that a very large item is the +waste work of converting the cellulose into nitrate, only to remove the +nitric groups so soon as the cellulose is obtained as thread. + +It is clear that the aqueous solutions of cellulose have a double +advantage in this respect--not only do they readily yield an +approximately pure cellulose as a direct product of regeneration or +decomposition, but the first cost of the solution is very much less. +With these newer products, therefore, the spinning problem enters on a +new phase of struggle. It is certain that at selling prices at or about +5s. to 7s., very large markets will be open to the product or +products. The two processes which are or may be able to fulfil this +demand are those based (1) on cuprammonium solutions of cellulose, (2) +on the sulphocarbonate or viscose. As regards _first cost_ of the +solution the latter has a large advantage. One ton of wood pulp (at +12l.) can certainly be obtained in solution in a condition ready for +spinning at a total cost (materials) of less than 30l. The +cuprammonium process, so far as 'outside' information goes, requires for +production of the solution (1) cotton as raw material, (2) ammonia +(calc. as concentrated aqueous) equal to 1-1/2 times its weight, and +(3) metallic copper 25 p.ct. of its weight; and the costs are +approximately 100l. per ton. It is obvious that the materials are +recoverable from the precipitating-bath, but at a certain added cost. We +have no statements as to the proportion recoverable nor the costs +incurred, and we are therefore unable to measure the total net cost of +the regenerated cellulose by this process. It is certainly much less +than by the collodion processes. As to the textile quality of the +thread, the product has not yet been on a sufficiently wide selling +basis for that to have been determined. There are a great many factors +which enter here. Not merely the external characters of lustre, +softness, and translucency, but the all-important quality of uniformity +of thread. The collodion-spinning is a process still very defective in +this respect, and the defect is no doubt referable to the difficulty of +securing absolute physical invariability of the collodion. It is to be +regretted, in the interests of scientific development, that none of the +technologists who have published investigations of these processes have +entered into the discussion of the fundamental factors of the spinning +processes; we are, therefore, unable at this stage to discuss these +elements of a full comparison in greater detail. We cannot, for this +reason, say how far the cuprammonium process diverges in point of +control from the standard of the collodion processes. Of the 'viscose' +product we have a more intimate knowledge, and it certainly reaches a +higher general standard than the older and now well-known artificial +silks. The process is also sufficiently developed to enable the total +costs of production to be estimated at a figure less than one-half that +of the 'collodion' processes. This would assure to this system an +_entrée_ in this country, and a basis of expansion limited only by the +ordinary laws of supply and demand. + +This prospect is opened up precisely at the moment when, for various +reasons connected both with the difficulties of manufacture and the +narrowing of the margin of profit, the proprietors of the two systems of +collodion-spinning have decided to abandon all idea of manufacturing by +these systems in this country.[15] We leave the discussion of the +industrial problem at this point. + +In regard to other developments based upon the exceptional character and +properties of the sulphocarbonate, their further discussion will +exemplify no general principles; and as regards technical detail they +have been dealt with in the papers previously noticed. + +As a purely general question, if there is to be any industry in these +'artificial' forms of cellulose, commensurate with the magnitude that +usually belongs to the cellulose industries, it must come by way of a +plastic or soluble form prepared at low cost, and conserving the +essential molecular properties of the cellulose aggregate. These are the +particular features of the sulphocarbonate. The obvious difficulties in +the way of its industrial applications are those caused by the presence +of alkali and sulphur compounds. These are dealt with by appropriate +chemical means; but the fact that there is a special chemistry of the +product has rendered its industrial progress slow. The work of the last +five years in this, as in other applications of cellulose in its many +derived forms, has resulted in a considerable addition to the domain of +practical chemistry. + +Further developments will make an increasing demand upon our grasp of +the fundamental constitutional problems, to which it is the main purpose +of the present volume to contribute. + +FOOTNOTES: + +[11] This is the most complete notice that has appeared and the +bibliography is exhaustive. The publication comes into our hands too +late to be noticed in detail. + +[12] _Text-book on Paper-making_, Cross and Bevan (Spon, London: second +edition, 1900). _Chemistry of Paper-making_, Griffin and Little (New +York, 1894: Howard Lockwood & Co.). _Handbuch d. Papierfabrikation_, C. +Hofmann (Berlin). _Paper Trade Review_, London (weekly). +_Papier-Zeitung_, Berlin. + +[13] William Mather, M.P., of the firm of Mather & Platt, Limited, +Manchester. + +[14] The actual costs varying considerably in the various countries, we +cannot make any specific statement. But from estimates we have made, the +costs of obtaining cotton in filtered solution as collodion multiply its +value by 12-14, the denitrations adding further costs and raising this +multiple to 18-20. In the same estimates we arrived at the conclusion +that the item for raw materials made up 60 p.ct. of the total cost of +the yarn. + +[15] The recent failure of a French company founded for the exploitation +of the cuprammonium process may be taken as showing that it presents +very considerable technical difficulties. It is a matter of common +knowledge that this company _estimated_ the costs of production to be +such as to enable the product to be sold at 12 fr. per kilo., whereas +the costs actually obtaining were a large multiple of this figure. + + + + +INDEX OF AUTHORS + + +Bardy, C. H., 157 + +Bokorny, T., 43 + +Bronnert, E., 54 + +Bumcke, G., and Wolffenstein, R., 67 + +Buntrock, 25 + + +Cross, C. F., 139, 152, 155 + +Cross, C. F., and Bevan, E. J., 92 + +Cross, C. F., Bevan, E. J., and Briggs, J. F., 118 + +Cross, C. F., Bevan, E. J., and Heiberg, T., 114 + +Cross, C. F., Bevan, E. J., and Smith, C., 101, 103, 105, 114, 145 + + +De Haas, R. W. T., and Tollens, B., 151 + + +Faber, O. v., and Tollens, B., 71 + +Feilitzen, H. v., and Tollens, B., 154 + +Fenton, H. J. H., 8 + +Fenton, H. J. H., and Gostling, M., 86 + +Fraenkel, A., and Friedlaender, P., 26 + + +Gardner, P., 22 + +Gilson, E., 112 + + +Hancock, W. C., and Dahl, O. W., 135 + +Hoffmeister, W., 96, 100 + + +Kleiber, A., 97 + +Kröber, E., 121 + +Krüger, M., 119 + + +Lange, H., 25 + +Lewes, V. H., 15 + +Luck, A., and Cross, C. F., 45 + + +Margosches, B. M., 159 + +Morrell, R. S., and Crofts, J. M., 114 + +Mylius, F., 21 + + +Nastukoff, H., 74 + + +Omelianski, V., 76 + + +Ruff, O., 117 + + +Salkowski, E., 113 + +Schöne, A., and Tollens, B., 124 + +Seidel, H., 149 + +Sherman, H. C., 137 + +Simonsen, E., 146 + +Storer, F. H., 142 + +Strehlenert, R. W., 158 + +Suringar, H., and Tollens, B., 16, 124 + +Süvern, C., 63 + + +Tollens, B., 148, 151 + +Tollens, B., and Glaubitz, H., 122 + + +Vignon, L., 43, 70, 72, 94 + + +Will, W., and Lenze, P., 41 + +Winterstein, E., 109, 144, 153 + + + + +INDEX OF SUBJECTS + + +Acetone, action on cellulose nitrates of diluted, 46 + +Acid-cellulose, 68 + +Acids, volatile, from cellulose, 145 + +_Æschynomene aspera_, 135 + +Alcohol from cellulose and wood, 146 + +Alcoholic soda, mercerisation results with, 26 + +Alkali-cellulose, effects of long storage on, 31 + +Amyloid, vegetable, 153 + +Arabinose from gluconic acid, 117 + +'Ash' of plants, 13 + + +_Bacterium xylinum_, 85 + +Barley plant, chemical processes in the, 103 + +---- straw, carbohydrates of, 105 + +Bleaching, 166 + +Bran, digestion of, 139 + +Brommethylfurfural, 8, 84, 86 + + +Carbohydrates, action of hydrogen bromide on, 86; + action of hydrogen peroxide on, 114; + nitrated, as food for mould fungi, 43; + nitrates of, 41; + quantitative separation of, 96 + +Carbohydrates of barley straw, 105; + of wheat, 137; + of yeast, 113 + +'Caro's reagent,' 118 + +'Celloxin,' 71 + +Cellulose, alcohol from, 146; + constitution of, 77, 92; + fermentation of, 76; + industrial uses of, 155; + iodine reaction of, 21; + methods for the estimation of, 3, 4, 16, 19, 97; + nitration of, 43; + saccharification of, 73; + ultimate hydrolysis of, 11; + volatile acids from, 145 + +---- acetates, monoacetate, formation of, 40; + tetracetate, constitution of, 80 + +---- benzoates, 34; + from structureless cellulose, 36; + from three varieties of cotton, 35; + monobenzoate, properties of, 36; + dibenzoate, properties of, 37; + acetylation of, 130; + nitration of, 38 + +---- derivatives, commercial aspects of, 171; + saccharification of, 73 + +---- nitrates, 44, 45, 83; + structureless, 45, 51; + cupric reducing power of, 73; + instability of, 50, 53 + +---- sulphocarbonate, 27; + effects of the nature of the cellulose, 28; + +---- ---- solutions, analysis of, 32; + iodine reaction of, 33; + loss of carbon bisulphide, 33; + viscosity of, 30 + +Cell-wall constituents, 97 + +Cereal celluloses, 101, 105 + +Chitin, 112 + +Chlorination, Cross and Bevan's method, 19; + statistics of, 134 + +Chloro-lignone, 126 + +Collodion. _See_ Silk, artificial + +Cotton, lustreing effect of mercerisation, 23; + mercerised, structural properties of, 25; + pentosane content of, 148 + +'Crude fibre,' 17 + +Cuprammonium solvent, 21, 58, 173 + +Currants, pectin of, 152 + + +Denitration of collodion silk, 56; + of jute nitrate, 133; + products of, 74 + +Dioxybutyric acid, 71 + + +Elder pith, 137 + +Eriodendron, seed hair of, 92 + +Explosives, 44; + sporting powders, 52 + + +Fermentation of cellulose, 76; + of furfuroids, 108; + of sugar from wood, 148 + +Fibres, report on miscellaneous, 139 + +Flax boiling, 168; + spinning, 161 + +Fodder plants, pentosanes of, 122 + +Fungi, tissue constituents of, 109 + +Furfural from cellulose, oxycellulose, and hydrocellulose, 70; + derivative from lævulose, 8; + estimation as hydrazone and phloroglucide, 119, 121; + oxidation of, 114, 118 (_refer also_ 'Pentosanes') + +Furfuroids, 8, 10, 102, 105; + assimilation of, 108 + + +Gabriel's method of cellulose estimation, 18 + +Gluconic acid, action of hydrogen peroxide on, 117 + +Glucosamin, 112 + + +Hemicellulose, 96, 97; + determination and separation of, 100 + +Hönig's method of cellulose estimation, 18 + +'Hydralcellulose,' 68 + +Hydrocellulose, 73; + nitration of, 43 + +Hydrogen peroxide, oxidations with, 114 + +Hydroxyfurfural in lignocellulose, 9, 116, 118 + + +Incandescent mantles of artificial silk, 14, 15 + +Industrial appliances of cellulose, 155 + +Iodine reaction of cellulose, 21 + +Isosaccharinic acid, 71 + + +Jute, composition of, 141; + quality of, 140; + treatment of, 142 (_refer also_ Lignocellulose) + +---- acetate, 129 + +---- benzoate, 127; + acetylation of, 130; + nitration of, 132 + +---- nitrate, 131 + + +Ketoses, physiological importance of, 9 + + +Lange method of cellulose estimation, 18, 98 + +Lead compounds of nitrated carbohydrates, 49 + +Lignin, 100 + +Lignocellulose, constitution of, 133; + esters of, 125; + hydroxyfurfural in, 9; + new type of, 135 + +Lignone complex, properties of, 126 + +'Lignorosin,' 151 + +'Lustra-cellulose.' _See_ Silk, artificial + + +Malt, pentosanes of, 122 + +Mather system of boiling textiles, 167 + +Mercerization, 22; shrinkage during, 24 + +Mercerised yarn, strength and elasticity of, 25, 26 + +Methylhydroxyfurfural, 84 + +Mould fungi, nitrated carbohydrates as food for, 43 + +Mycosin, 113 + + +Nitrated carbohydrates, lead compounds of, 49 + +Nitrates of carbohydrates, 41 + +Nitrocellulose (_see_ Cellulose nitrates); + silk, 55 + +'Normal' cellulose, definition of, 27 + +Normal paper, 160 + + +Oxycellulose esters, 72; + nitration of, 43; + researches on, 71, 72, 74; + _résumé_ of properties, 94 + +Oxygluconic acid, 117 + + +Paper, deterioration of, 155; + normal standard, 160; + pulp, spinning of, 169 + +Peat, constituents of, 154 + +Pectins, 151, 152 + +Pentosanes, 100, 109, 144; + constituents of cotton, 124; + constituents of fodder, 122; + estimation of, 121; + of seeds during germination, 124 + +'Permanent tissue,' 103 + +Phloroglucinol, 119, 121 + +Plant tissues, carbohydrates of, 96, 97, 99 + +Plants, source of unsaturated compounds in, 145 + +Powders, manufacture of sporting, 52 + + +Saccharification of cellulose and derivatives, 73 + +Schulze method of cellulose estimation, 18, 98 + +Schweizer solution, 101 + +Seeds, pentosanes in germinating, 124 + +Silica in plant tissues, 13 + +Silk, artificial, 54, 62, 63, 172; + bibliography of, 60; + from cuprammonium, 58, 64, 173; + from nitrocellulose (collodion), 55, 63, 172; + from viscose, 59; + from zinc chloride, 59; + reactions of, 64 + +---- natural, reactions of, 64 + +Straws, 101, 105 + +Succinic acid from furfural, 118 + +Sulphite waste liquors, 149, 164 + +'Swedish' filter paper, 14 + + +Tissue constituents, 99, 109 + +Trees, composition of trunk woods, 142 + + +Viscose and viscoid, 157, 158, 159 + +---- silk, 59, 175 + +---- ---- specific gravity of, 34 (_refer also_ Cellulose +sulphocarbonate) + +'Vulcanised fibre,' 20 + + +Weende, method of cellulose estimation (crude fibre), 17, 98 + +Welsbach mantles, 14; + Clamond type, 15 + +Wheat grain, insoluble carbohydrates of, 137 + +Wood, alcohol from, 146, 148 + +Wood-cellulose, waste liquors, 149 + +Wood-gum, 144 + +Wood-pulp, processes, 162 + +Wood, trunks of trees, 142 + + +Yeast, carbohydrates of, 113 + + +Zinc chloride, artificial silk, 59; + solvent action of, 20 + + + + + + +End of the Project Gutenberg EBook of Researches on Cellulose, by +C. 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