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diff --git a/old/65735-0.txt b/old/65735-0.txt deleted file mode 100644 index 4451d24..0000000 --- a/old/65735-0.txt +++ /dev/null @@ -1,11200 +0,0 @@ -The Project Gutenberg eBook of Michael Faraday, by Silvanus P. Thompson - -This eBook is for the use of anyone anywhere in the United States and -most other parts of the world at no cost and with almost no restrictions -whatsoever. You may copy it, give it away or re-use it under the terms -of the Project Gutenberg License included with this eBook or online at -www.gutenberg.org. If you are not located in the United States, you -will have to check the laws of the country where you are located before -using this eBook. - -Title: Michael Faraday - His Life and Work - -Author: Silvanus P. Thompson - -Release Date: June 30, 2021 [eBook #65735] - -Language: English - -Character set encoding: UTF-8 - -Produced by: Fay Dunn, Charlie Howard, and the Online Distributed - Proofreading Team at https://www.pgdp.net (This file was - produced from images generously made available by The Internet - Archive) - -*** START OF THE PROJECT GUTENBERG EBOOK MICHAEL FARADAY *** - - - - -Transcriber’s Note - - -Superscripts are preceded by a ^ or enclosed in ^{braces}; italics are -enclosed in _underscores_; boldface is enclosed in =equals signs=. - - - - - _THE CENTURY SCIENCE SERIES_ - - EDITED BY SIR HENRY E. ROSCOE, D.C.L., LL.D., F.R.S. - - - MICHAEL FARADAY - - HIS LIFE AND WORK - - - - -The Century Science Series. - -_Edited by_ SIR HENRY ROSCOE, D.C.L., F.R.S. - -3s. 6d. _each_. - - - Pasteur. - - By PERCY FRANKLAND, Ph.D.(Würzburg), B.Sc. (Lond.), F.R.S., and - Mrs. PERCY FRANKLAND. - - -Humphry Davy, Poet and Philosopher. - - By T. E. THORPE, LL.D., F.R.S. - - -Charles Darwin and the Theory of Natural Selection. - - By EDWARD B. POULTON, M.A., F.R.S. - - -John Dalton and the Rise of Modern Chemistry. - - By Sir HENRY E. ROSCOE, F.R.S. - - -Major Rennell, F.R.S., and the Rise of English Geography. - - By Sir CLEMENTS R. MARKHAM, C.B., F.R.S. - - -Justus von Liebig: his Life and Work (1803–1873). - - By W. A. SHENSTONE, F.I.C., Lecturer on Chemistry in Clifton - College. - - -The Herschels and Modern Astronomy. - - By AGNES M. CLERKE. - - -Charles Lyell and Modern Geology. - - By Professor T. G. BONNEY, F.R.S. - - -J. Clerk Maxwell and Modern Physics. - - By R. T. GLAZEBROOK, F.R.S. - - * * * * * - - -Michael Faraday: his Life and Work. - - By Prof. SILVANUS P. THOMPSON, F.R.S. 5s. - - - - -CASSELL & COMPANY, LIMITED, _London; Paris, New York & Melbourne_. - - - - -[Illustration: Ever Yours Truly - -M Faraday] - - - - - _THE CENTURY SCIENCE SERIES_ - - - MICHAEL FARADAY - - HIS LIFE AND WORK - - - BY - SILVANUS P. THOMPSON, D.Sc., F.R.S. - - PRINCIPAL OF AND PROFESSOR OF PHYSICS IN THE CITY AND GUILDS - OF LONDON TECHNICAL COLLEGE, FINSBURY - - - CASSELL AND COMPANY, LIMITED - _LONDON, PARIS, NEW YORK & MELBOURNE_ - 1898 - - [ALL RIGHTS RESERVED] - -[Illustration] - - -ON A PORTRAIT OF FARADAY. - - Was ever man so simple and so sage, - So crowned and yet so careless of a prize! - Great Faraday, who made the world so wise, - And loved the labour better than the wage. - - And this you say is how he looked in age, - With that strong brow and these great humble eyes - That seem to look with reverent surprise - On all outside himself. Turn o’er the page, - - Recording Angel, it is white as snow. - Ah God, a fitting messenger was he - To show Thy mysteries to us below. - Child as he came has he returned to Thee. - Would he could come but once again to show - The wonder-deep of his simplicity. - - COSMO MONKHOUSE. - - - - -PREFACE - - -Shortly after the death of Faraday in 1867, three biographies of -him--each admirable in its own line--were published. The “Life and -Letters of Faraday,” by Dr. Bence Jones, secretary of the Royal -Institution, which was issued in 1868 in two volumes, has long been -out of print. “Faraday as a Discoverer,” written in 1868 by Professor -Tyndall, which, though slighter as a record, brings out many points of -character into striking relief, is also now exhausted. Dr. Gladstone’s -“Michael Faraday,” published in 1872, so rich in reminiscences, and -so appreciative of the moral and religious side of his character, is -also out of print. Other and briefer biographies exist; the “Éloge -Historique” of M. Dumas; the article “Faraday” in the “Encyclopædia -Britannica” by Professor Clerk Maxwell; and the chapter on Faraday -in Dr. W. Garnett’s “Heroes of Science.” But there seems room for -another account of the life and labours of the man whose influence -upon the century in which he lived was so great. For forty years he -was a living and inspiring voice in the Royal Institution, beyond all -question the greatest scientific expositor of his time. Throughout -almost the whole of that time his original researches in physics, and -chiefly in electricity, were extending the boundaries of knowledge -and laying the foundations not only for the great developments of -electrical engineering of the last twenty years but for those still -greater developments in the theories of electricity, magnetism, and -light which are every year being extended and made fruitful. Were there -no other reason than these developments in practice and theory, they -would amply justify the effort to review now, after so many years, the -position of Faraday amongst the eminent men of the century now drawing -to its close. - -Those who were intimately acquainted with him are a fast dwindling -band. In the recollection of such as have survived him, his image lives -and moves, surrounded with gracious memories, a vivid personality -instinct with rare and unselfish kindliness. But the survivors are few, -and their ranks grow thinner with each succeeding year. And so it comes -about that the task of writing of his life and work has been entrusted -to one who never ceases to regret that he never met Faraday. - -Thanks to the permission of the managers of the Royal Institution, -a number of short extracts from Faraday’s notebooks, hitherto -unpublished, are now printed for the first time. Much more remains -which it is to be hoped, for the benefit of science, may be published -ere long. The author desires further to acknowledge the kindness -of Messrs. Longmans & Co. in allowing the reproduction of the -illustrations on pages 3 and 258, which are taken from Bence Jones’s -“Life and Letters of Faraday,” published in 1868. Mr. Elkin Mathews has -kindly permitted the insertion of the sonnet by Mr. Cosmo Monkhouse -which follows the title-page. The author is also indebted to Dr. J. -Hall Gladstone, F.R.S., for many valuable notes and suggestions, and to -Miss M. K. Reynolds for photographs used in preparing Fig. 14. Most of -all he is indebted to Miss Jane Barnard for access to Faraday’s private -papers, and for permission to print certain extracts from them. - - S. P. T. - - - - -CONTENTS - - - PAGE - CHAP. I.--EARLY LIFE, TRAINING, AND TRAVEL 1 - - CHAP. II.--LIFE AT THE ROYAL INSTITUTION 35 - - CHAP. III.--SCIENTIFIC RESEARCHES--FIRST PERIOD 75 - - CHAP. IV.--SCIENTIFIC RESEARCHES--SECOND PERIOD 102 - - CHAP. V.--SCIENTIFIC RESEARCHES--THIRD PERIOD 172 - - CHAP. VI.--MIDDLE AND LATER LIFE 222 - - CHAP. VII.--VIEWS ON THE PURSUIT OF SCIENCE AND ON EDUCATION 261 - - CHAP. VIII.--RELIGIOUS VIEWS 286 - - - - -LIST OF ILLUSTRATIONS - - - Portrait _Frontispiece_ - - FIGS. PAGE - 1. Riebau’s Shop 3 - 2. Electromagnetic Rotations (facsimile sketch) 88 - 3. Apparatus for Rotation (facsimile sketch) 88 - 4. Faraday’s Ring (facsimile sketch) 108 - 5. Induction Experiment (facsimile sketch) 111 - 6. The “New Electrical Machine” (facsimile sketch) 121 - 7. The Teetotum Apparatus 123 - 8. The Revolving Copper Cylinder (facsimile sketch) 124 - 9. Earth Inductor 125 - 10. A Spark from a Magnet (facsimile sketch) 129 - 11. How to Cut the Magnetic Lines 133 - 12. Illustration of the New Terms (facsimile sketch) 145 - 13. Bundle of Wires (facsimile sketch) 151 - 14. Apparatus for Investigating Dielectric Capacity 159 - 15. Block of Heavy-glass (facsimile sketch) 176 - 16. Action of Magnet on Light (facsimile sketch) 177 - 17. Arrangements of Magnets (facsimile sketch) 178 - 18. The Ring Electromagnet (facsimile sketch) 179 - 19. The Equatorial Position 188 - 20. Illustration of Lateral Vibrations 195 - 21. A Lecture Model 239 - 22. Cottage at Hampton Court 258 - - - - -MICHAEL FARADAY. - - - - -CHAPTER I. - -EARLY LIFE, TRAINING, AND TRAVEL. - - -On the 22nd of September, 1791, was born, at Newington Butts, then an -outlying Surrey village, but since long surrounded and swallowed up -within the area of Greater London, the boy Michael Faraday. He was -the third child of his parents, James and Margaret Faraday, who had -but recently migrated to London from the little Yorkshire village of -Clapham. Clapham lies under the shadow of Ingleborough, on the western -border of the county, midway between Settle and Kirkby Lonsdale. -The father, James Faraday, was a working blacksmith; the mother, -daughter of a farmer of Mallerstang, the romantic valley which runs -past Pendragon Castle to Kirkby Stephen. James Faraday was one of the -ten children of a Robert Faraday, who in 1756 had married Elizabeth -Dean, the owner of a small homestead known as Clapham Wood Hall, since -pulled down. All Robert Faraday’s sons appear to have been brought up -to trades, one being a shoemaker, another a grocer, another a farmer, -another a flax-worker, and another a shopkeeper. Descendants of some of -these still live in the district. - -After Michael’s birth, his parents moved to the north side of the -Thames, living for a short time in Gilbert Street, but removing in -1796 to rooms over a coach-house in Jacob’s Well Mews, Charles Street, -Manchester Square, where they lived till 1809. In that year, young -Michael being now nearly eighteen years old, they moved to 18, Weymouth -Street, Portland Place. Here in the succeeding year James Faraday, who -had long been an invalid, died; his widow, who for some years remained -on at Weymouth Street, maintaining herself by taking in lodgers until -her sons could support themselves and her, survived till 1838. Though -a capable woman and a good mother, she was quite uneducated. In her -declining years she was wholly supported by her son, of whom she was -very proud, and to whom she was devoted. - -Michael received very little schooling. One of his nephews tells -the following tale of his boyhood. He was at a dame’s school; and, -either from some defect in his speech or because he was too young -to articulate his _r_’s properly, he pronounced his elder brother’s -name “Wobert.” The harsh schoolmistress, bent on curing the defect by -personal chastisement, sent the aforesaid “Wobert” out with a halfpenny -to get a cane, that young Michael might be duly flogged. But this -refinement of cruelty reacted on itself; for Robert, boiling with -indignation, pitched the halfpenny over a wall, and went home to tell -his mother, who promptly came down to the scene of action and removed -both boys from the school. From the age of five to thirteen Michael -lived at Jacob’s Well Mews, spending his out-of-school hours at home or -in the streets playing at marbles and other games with the children of -the neighbourhood. - -[Illustration: RIEBAU’S SHOP.] - -[Sidenote: BOOKBINDER’S ERRAND-BOY.] - -In 1804 he went on trial for twelve months as errand-boy to a -bookseller and stationer at No. 2, Blandford Street--Mr. George Riebau. -This house, which is still kept as a stationer’s shop (by Mr. William -Pike), is now marked with an enamelled tablet recording its connection -with the life of Faraday.[1] When he first went to Mr. Riebau, it was -his duty to carry round the newspapers in the morning. He has been -graphically described as a bright-eyed errand-boy who “slid along the -London pavements, with a load of brown curls upon his head and a packet -of newspapers under his arm.” Some of the journals were lent out, and -had to be called for again. He was very particular on Sunday mornings -to take them round early, that he might complete his work in time to -go with his parents to their place of worship. They belonged--as his -grandfather before him--to the sect known as Sandemanians, a small -body which separated from the Presbyterian Church of Scotland towards -the middle of the eighteenth century. Their views, which were very -primitive, were held with intense earnestness and sincerity of purpose. -Their founder had taught that Christianity never was or could be the -formal or established religion of any nation without subverting its -essential principles; that religion was the affair of the individual -soul; and that “the Bible” alone, with nothing added to it or taken -away from it by man, was the sole and sufficient guide for the soul. -They rejected all priests or paid ministers, but recognised an -institution of unpaid eldership. Their worship was exceedingly simple. -Though their numbers were few, they were exceedingly devout, simple, -and exclusive in their faith. Doubtless the rigorous moral influences -pervading the family and friends of James Faraday had a great part in -moulding the character of young Michael. To his dying day he remained a -member of this obscure sect. As he was no merely nominal adherent, but -an exceedingly devoted member, and at two different periods of his life -an elder and a preacher, no review of his life-work would be complete -without a fuller reference to the religious side of his character. - -[Sidenote: APPRENTICED AS BOOKBINDER.] - -After the year of trial, Michael Faraday was formally apprenticed to -learn the arts of bookbinder, stationer, “and bookseller,” to Mr. -Riebau. The indenture[2] is dated October 7, 1805. It is stated that, -“in consideration of his faithful service, no premium is given.” During -his seven years of apprenticeship there came unexpected opportunities -for self-improvement. Faraday’s lifelong friend and co-religionist, -Cornelius Varley, says:--“When my attention was first drawn to Faraday, -I was told that he had been apprenticed to a bookbinder. I said he -was the best bookworm for eating his way to the inside; for hundreds -had worked at books only as so much printed paper. Faraday saw a mine -of knowledge, and resolved to explore it.” To one of his friends he -said that a book by Watts, “On the Mind,” first made him think, and -that the article on “Electricity” in a cyclopædia which came into his -hands to be bound first turned his attention to science. He himself -wrote:--“Whilst an apprentice I loved to read the scientific books -which were under my hand; and, amongst them, delighted in Marcet’s -‘Conversations in Chemistry’ and the electrical treatises in the -‘Encyclopædia Britannica.’ I made such simple experiments in chemistry -as could be defrayed in their expense by a few pence per week, and -also constructed an electrical machine, first with a glass phial, and -afterwards with a real cylinder, as well as other electrical apparatus -of a corresponding kind.” This early machine[3] is now preserved at -the Royal Institution, to which it was presented by Sir James South. -Amongst the books which he had to bind were Lyons’ “Experiments on -Electricity” and Boyle’s “Notes about the Producibleness of Chymicall -Principles,” which books, together with Miss Burney’s “Evelina,” all -bound with his own hands, are still preserved in the Royal Institution. - -[Sidenote: NEW ACQUAINTANCES.] - -Walking near Fleet Street, he saw displayed a bill announcing that -evening lectures on natural philosophy were delivered by Mr. Tatum -at 53, Dorset Street, Salisbury Square, E.C., price of admission one -shilling. With his master’s permission, and money furnished by his -elder brother Robert, who was a blacksmith and (later) a gasfitter, -Michael began to taste scientific teaching. Between February, 1810, -and September, 1811, he attended some twelve or thirteen lectures. He -made full and beautiful notes of all he heard: his notebooks, bound -by himself, being still preserved. At these lectures he fell in with -several thoroughly congenial comrades, one of them, by name Benjamin -Abbott, being a well-educated young Quaker, who was confidential -clerk in a mercantile house in the City. Of the others--amongst -whom were Magrath, Newton, Nicol, Huxtable, and Richard Phillips -(afterwards F.R.S. and President of the Chemical Society)--several -remained lifelong friends. Happily for posterity, the letters--long -and chatty--which the lad wrote in the fulness of his heart to Abbott -have been preserved; they are published in Bence Jones’s “Life and -Letters.” They are remarkable not only for their vivacity and freshness -but for their elevated tone and excellent composition--true specimens -of the lost art of letter-writing. The most wonderful thing about them -is that they should have been written by a bookbinder’s apprentice of -no education beyond the common school of the district. In his very -first letter he complains that ideas and notions which spring up in his -mind “are irrevocably lost for want of noting at the time.” This seems -the first premonition of that loss of memory which so afflicted him -in after life. In his later years he always carried in his waistcoat -pocket a card on which to jot down notes and memoranda. He would -stop to set down his notes in the street, in the theatre, or in the -laboratory. - -Riebau, his master in the bookbinding business, seems, from the way -he encouraged the studies of his young apprentice, to have been no -ordinary man. His name would suggest a foreign extraction; and to his -shop resorted more than one political refugee. There lodged at one time -at Riebau’s an artist named Masquerier,[4] who had painted Napoleon’s -portrait and had fled from France during the troublous times. For -the apprentice boy, who used to dust his room and black his boots, -Masquerier took a strong liking. He lent him books on perspective -and taught him how to draw. Another frequenter of Riebau’s shop was -a Mr. Dance, whose interest in the industry and intelligence of the -apprentice led him to an act which changed the whole destiny of his -life. Faraday himself, in the very few autobiographical notes which he -penned, wrote thus:-- - - During my apprenticeship I had the good fortune, through the - kindness of Mr. Dance, who was a customer of my master’s shop - and also a member of the Royal Institution, to hear four of the - last lectures of Sir H. Davy in that locality.[5] The dates - of these lectures were February 29, March 14, April 8 and 10, - 1812. Of these I made notes, and then wrote out the lectures in - a fuller form, interspersing them with such drawings as I could - make. The desire to be engaged in scientific occupation, even - though of the lowest kind, induced me, whilst an apprentice, - to write, in my ignorance of the world and simplicity of my - mind, to Sir Joseph Banks, then President of the Royal Society. - Naturally enough, “No answer” was the reply left with the - porter. - -[Sidenote: LETTERS TO ABBOTT.] - -He submitted his notes to the criticism of his friend Abbott, with whom -he discussed chemical and electrical problems, and the experiments -which they had individually tried. Out of this correspondence, one -letter only can be given; it was written September 28, 1812, ten days -before the expiry of his apprenticeship:-- - - Dear A----, ... I will hurry on to philosophy, where I am a - little more sure of my ground. Your card was to me a very - interesting and pleasing object. I was highly gratified in - observing so plainly delineated the course of the electric - fluid or fluids (I do not know which). It appears to me that by - making use of a card thus prepared, you have hit upon a happy - illustrating medium between a conductor and a non-conductor; - had the interposed medium been a conductor, the electricity - would have passed in connection through it--it would not have - been divided; had the medium been a non-conductor, it would - have passed in connection, and undivided, as a spark over - it, but by this varying and disjoined conductor it has been - divided most effectually. Should you pursue this point at - any time still further, it will be necessary to ascertain by - what particular power or effort the spark is divided, whether - by its affinity to the conductor or by its own repulsion; or - if, as I have no doubt is the case, by the joint action of - these two forces, it would be well to observe and ascertain - the proportion of each in the effect. There are problems, - the solution of which will be difficult to obtain, but the - science of electricity will not be complete without them; - and a philosopher will aim at perfection, though he may not - hit it--difficulties will not retard him, but only cause a - proportionate exertion of his mental faculties. - - I had a very pleasing view of the planet Saturn last week - through a refractor with a power of ninety. I saw his ring - very distinctly; ’tis a singular appendage to a planet, to - a revolving globe, and I should think caused some peculiar - phenomena to the planet within it. I allude to their mutual - action with respect to meteorology and perhaps electricity.... - -The master, a French emigré named De la Roche, of King Street, Portman -Square, to whom he engaged himself as a journeyman bookbinder, was of -a very passionate disposition, and made Faraday very uncomfortable. He -longed to get out of trade, and under the encouragement of Mr. Dance -he wrote to Sir Humphry Davy, sending, “as a proof of my earnestness,” -the notes he had taken of Davy’s last four lectures. Faraday’s letter, -which has been preserved but never published, is an astounding example -of the high-flown cringing style in vogue at that date. Davy’s reply -was favourable, and led to a temporary engagement of some days as -amanuensis at the time when he was wounded in the eye by an explosion -of the chloride of nitrogen. Faraday himself, nearly twenty years -afterwards, wrote[6] a full account of the circumstances. - - [_M. Faraday to Dr. J. A. Paris._] - - Royal Institution, December 23, 1829. - - MY DEAR SIR,--You asked me to give you an account of my first - introduction to Sir H. Davy, which I am very happy to do, as I - think the circumstances will bear testimony to his goodness of - heart. - - When I was a bookseller’s apprentice, I was very fond of - experiment and very adverse to trade. It happened that a - gentleman, a member of the Royal Institution, took me to hear - some of Sir H. Davy’s last lectures in Albemarle Street. I took - notes, and afterwards wrote them out more fairly in a quarto - volume. - - My desire to escape from trade, which I thought vicious and - selfish, and to enter into the service of Science, which I - imagined made its pursuers amiable and liberal, induced me at - last to take the bold and simple step of writing to Sir H. - Davy, expressing my wishes, and a hope that, if an opportunity - came in his way, he would favour my views; at the same time, I - sent the notes I had taken of his lectures. - - The answer, which makes all the point of my communication, I - send you in the original, requesting you to take great care of - it, and to let me have it back, for you may imagine how much I - value it. - - You will observe that this took place at the end of the year - 1812, and early in 1813 he requested to see me, and told me - of the situation of assistant in the laboratory of the Royal - Institution, then just vacant. - - At the same time that he thus gratified my desires as to - scientific employment, he still advised me not to give up the - prospects I had before me, telling me that Science was a harsh - mistress; and in a pecuniary point of view but poorly rewarding - those who devoted themselves to her service. He smiled at my - notion of the superior moral feelings of philosophic men, and - said he would leave me to the experience of a few years to set - me right on that matter. - - Finally, through his good efforts I went to the Royal - Institution early in March of 1813, as assistant in the - laboratory; and in October of the same year went with him - abroad as his assistant in experiments and in writing. I - returned with him in April, 1815, resumed my station in the - Royal Institution, and have, as you know, ever since remained - there. - - I am, dear Sir, very truly yours, - M. FARADAY. - - -[Sidenote: WINS FAVOUR WITH DAVY.] - -The following is Davy’s note:-- - - _Mr. P. Faraday, 188, Weymouth St., Portland Place._ - - December 24, 1812. - - SIR,--I am far from displeased with the proof you have given - me of your confidence, and which displays great zeal, power - of memory, and attention. I am obliged to go out of Town, and - shall not be settled in town till the end of Jan^y I will then - see you at any time you wish. It would gratify me to be of any - service to you; I wish it may be in my power. - - I am Sir - your obt. humble servt. - H. DAVY. - - -Accordingly, Faraday called on Davy, who received him in the anteroom -to the lecture theatre, by the window nearest to the corridor. He -advised him then to stick to bookbinding, promising to send him books -from the Institution to bind, as well as other books. He must have been -agreeably impressed, otherwise he would not, when disabled, have sent -for Faraday to write for him. Early in 1813 the humble household, in -which Faraday lived with his widowed mother in Weymouth Street, was one -night startled by the apparition of Sir Humphry Davy’s grand coach, -from which a footman alighted and knocked loudly at the door. For young -Faraday, who was at that moment undressing upstairs, he left a note -from Sir Humphry Davy requesting him to call next morning. At that -interview Davy asked him whether he was still desirous of changing his -occupation, and offered him the post of assistant in the laboratory in -place of one who had been dismissed. The salary was to be twenty-five -shillings a week, with two rooms at the top of the house. The minute -appointing him is dated March 1, 1813:-- - -[Sidenote: ENTERS ROYAL INSTITUTION.] - - Sir Humphry Davy has the honour to inform the managers that - he has found a person who is desirous to occupy the situation - in the Institution lately filled by William Payne. His name - is Michael Faraday. He is a youth of twenty-two years of age. - As far as Sir H. Davy has been able to observe or ascertain, - he appears well fitted for the situation. His habits seem - good, his disposition active and cheerful, and his manner - intelligent. He is willing to engage himself on the same - terms as those given to Mr. Payne at the time of quitting the - Institution. - - Resolved--That Michael Faraday be engaged to fill the situation - lately occupied by Mr. Payne on the same terms.[7] - -There have come down several additions to the story. One, probably -apocryphal, says that Faraday’s first introduction to Davy was -occasioned by Davy’s calling at Riebau’s to select some bookbinding, -and seeing on the shelves the bound volume of manuscript notes of -his own lectures. The other was narrated by Gassiot to Tyndall, as -follows:-- - - Clapham Common, Surrey, - November 28, 1867. - - MY DEAR TYNDALL,--Sir H. Davy was accustomed to call on the - late Mr. Pepys in the Poultry, on his way to the London - Institution, of which Pepys was one of the original managers; - the latter told me that on one occasion Sir H. Davy, showing - him a letter, said, “Pepys, what am I to do?--here is a letter - from a young man named Faraday; he has been attending my - lectures, and wants me to give him employment at the Royal - Institution--what can I do?” “Do?” replied Pepys, “put him - to wash bottles; if he is good for anything he will do it - directly; if he refuses, he is good for nothing.” “No, no,” - replied Davy, “we must try him with something better than - that.” The result was, that Davy engaged him to assist in the - Laboratory at weekly wages. - - Davy held the joint office of Professor of Chemistry and - Director of the Laboratory; he ultimately gave up the former to - the late Professor Brande, but he insisted that Faraday should - be appointed Director of the Laboratory, and, as Faraday told - me, this enabled him on subsequent occasions to hold a definite - position in the Institution, in which he was always supported - by Davy. I believe he held that office to the last. - - Believe me, my dear Tyndall, yours truly, - J. P. GASSIOT. - - -In 1808 Mr. Tatum had founded a City Philosophical Society.[8] It -consisted of thirty or forty young men in humble or moderate rank, who -met on Wednesdays for mutual instruction; lectures being given once -a fortnight by the members in turn. Tatum introduced Faraday to this -Society in 1813. Edward Magrath was secretary. Amongst Faraday’s notes -of his life is the following:-- - - During this spring Magrath and I established the - mutual-improvement plan, and met at my rooms up in the attics - of the Royal Institution, or at Wood Street at his warehouse. - It consisted perhaps of half-a-dozen persons, chiefly from - the City Philosophical Society, who met of an evening to read - together, and to criticise, correct, and improve each other’s - pronunciation and construction of language. The discipline was - very sturdy, the remarks very plain and open, and the results - most valuable. This continued for several years. - -[Sidenote: AT WORK IN CHEMISTRY.] - -He writes, after a week of work at the Royal Institution, to Abbott:-- - - Royal Institution, March 8, 1813. - - It is now about nine o’clock, and the thought strikes me that - the tongues are going both at Tatum’s and at the lecture in - Bedford Street; but I fancy myself much better employed than - I should have been at the lecture at either of those places. - Indeed, I have heard one lecture already to-day, and had a - finger in it (I can’t say a hand, for I did very little). It - was by Mr. Powell, on mechanics, or rather on rotatory motion, - and was a pretty good lecture, but not very fully attended. - - As I know you will feel a pleasure in hearing in what I have - been or shall be occupied, I will inform you that I have been - employed to-day, in part, in extracting the sugar from a - portion of beetroot, and also in making a compound of sulphur - and carbon--a combination which has lately occupied in a - considerable degree the attention of chemists. - - With respect to next Wednesday, I shall be occupied until late - in the afternoon by Sir H. Davy, and must therefore decline - seeing you at that time; this I am the more ready to do as I - shall enjoy your company next Sunday, and hope to possess it - often in a short time. - -The next letter to Abbott, dated April 9, recounts an explosion in -which both he and Sir Humphry Davy received considerable injury. -In June he wrote to Abbott four very remarkable letters concerning -lectures and lecturers. He had already heard Tatum and Davy, and had -now assisted Brande and Powell in their lectures, and had keenly -observed their habits, peculiarities, and defects, as well as the -effects they produced on the audience. He writes without the slightest -suspicion of suggestion that he himself has any likelihood of becoming -a lecturer, and says that he does not pretend to any of the requisites -for such an office. “If I am unfit for it,” he says, “’tis evident -that I have yet to learn; and how learn better than by the observation -of others? If we never judge at all, we shall never judge right.” “I, -too, have inducements in the C[ity] P[hilosophical] S[ociety] to draw -me forward in the acquisition of a small portion of knowledge on this -point.” “I shall point out but few beauties or few faults that I have -not witnessed in the presence of a numerous assembly.” - -He begins by considering the proper shape of a lecture-room; its proper -ventilation, and need of suitable entrances and exits. Then he goes -on to consider suitability of subjects and dignity of subject. In the -second of the letters he contrasts the perceptive powers of the eye and -ear, and the proper arrangements for a lecturer’s table; then considers -diagrams and illustrations. The third letter deals with the delivery -and style of the lecture, the manner and attitudes of the lecturer, his -methods of keeping alive the attention of the audience, and duration of -the discourse. In the fourth of these letters (see p. 228), he dwells -on the mistakes and defects of lecturers, their unnecessary apologies, -the choice of apt experiments, and avoidance of trivialities. - -[Sidenote: PROPOSALS FOR FOREIGN TRAVEL.] - -In September, 1813, after but six months of work in the laboratory, -a proposition came to him from Sir Humphry Davy which resulted in -a complete change of scene. It was an episode of foreign travel, -lasting, as it proved, eighteen months. In the autobiographical notes -he wrote:-- - - In the autumn Sir H. Davy proposed going abroad, and offered - me the opportunity of going with him as his amanuensis, and - the promise of resuming my situation in the Institution upon - my return to England. Whereupon I accepted the offer, left the - Institution on October 13, and, after being with Sir H. Davy in - France, Italy, Switzerland, the Tyrol, Geneva, &c., in that and - the following year, returned to England and London April 23, - 1815. - -Before he left England, on September 18, 1813, at the request of -his mother, he wrote to an uncle and aunt the following account of -himself:-- - - I was formerly a bookseller and binder, but am now turned - philosopher, which happened thus:--Whilst an apprentice, I, - for amusement, learnt a little of chemistry and other parts - of philosophy, and felt an eager desire to proceed in that - way further. After being a journeyman for six months, under - a disagreeable master, I gave up my business, and, by the - interest of Sir H. Davy, filled the situation of chemical - assistant to the Royal Institution of Great Britain, in - which office I now remain, and where I am constantly engaged - in observing the works of Nature and tracing the manner in - which she directs the arrangement and order of the world. I - have lately had proposals made to me by Sir Humphry Davy to - accompany him, in his travels through Europe and into Asia, as - philosophical assistant. If I go at all I expect it will be - in October next, about the end, and my absence from home will - perhaps be as long as three years. But as yet all is uncertain. - I have to repeat that, even though I may go, my path will not - pass near any of my relations, or permit me to see those whom I - so much long to see. - -To Faraday, who was now twenty-two years old, foreign travel meant much -more than to most young men of equal age. With his humble bringing -up and slender resources, he had never had the chance of seeing the -outside world; he had never, to his own recollection, even seen the -sea. When on Wednesday, October 13, he started out on the journey -to Plymouth, in order to cross to the port of Morlaix, he began his -journal of foreign travel thus:-- - - This morning formed a new epoch in my life. I have never - before, within my recollection, left London at a greater - distance than twelve miles. - -[Sidenote: A NEW ELEMENT.] - -This journal he kept with minute care, with the sole purpose of -recalling events to his mind. It gives full details as to Davy’s -scientific friends and work, intermingled with graphic descriptions -of scenery; and is remarkable also for its personal reticence. As -with many another, so with Faraday, foreign travel took in his life -the place of residence at a University. In France, in Italy, he -received enlarged ideas; and what he saw of learned men and academies -of science exercised no small formative effect upon one then at the -most impressionable age. He comments gaily on the odd incidents of -travel; the luminescence of the sea at night; the amazing fuss at the -Custom House; the postilion with his jack-boots, whip, and pouch; the -glow-worm (the first glow-worm he had ever seen); and the slim pigs of -Normandy. At Paris he visits the Louvre, where his chief comment on -its treasures is, that by their acquisition France has made herself -“a nation of thieves.” He goes to the Prefecture of Police for his -passport, in which he is described as having “a round chin, a brown -beard, a large mouth, a great nose,” etc. He visits the churches, -where the theatrical air pervading the place “makes it impossible to -attach a serious or important feeling to what is going on.” He comments -on the wood fires, the charcoal used in cooking, the washerwomen on -the river bank, the internal decorations of houses, the printing of -the books. Then he goes about with Davy amongst the French chemists. -Ampère, Clément, and Désormes come to Davy to show him the new and -strange substance “X,” lately discovered by M. Courtois. They heat -it, and behold it rise in vapour of a beautiful violet colour. Ampère -himself, on November 23rd, gives Davy a specimen. They carefully note -down its characters. Davy and his assistant make many new experiments -on it. At first its origin is kept a profound secret by the Frenchman. -Then it transpires that it is made from ashes of seaweed. They work -on it at Chevreul’s laboratory. Faraday borrows a voltaic pile from -Chevreul. With that intuition which was characteristic of him, Davy -jumps almost at once to a conclusion as to the nature of the new body, -which for nearly two years had been in the hands of the Frenchmen -awaiting elucidation. When he leaves Paris, they do not wholly -bless his rapidity of thought. But Faraday has seen--with placid -indifference--a glimpse of the great Napoleon “sitting in one corner -of his carriage, covered and almost hidden by an enormous robe of -ermine, and his face overshadowed by a tremendous plume of feathers, -that descended from a velvet hat”; he has also met Humboldt, and he has -heard M. Gay Lussac lecture to about two hundred pupils. - -Dumas has recorded in his “Éloge Historique” a reflection of the -impressions left by the travellers. After speaking of the criticism to -which Davy was exposed during his visit, he says:-- - - His laboratory assistant, long before he had won his great - celebrity by his works, had by his modesty, his amiability, - and his intelligence, gained most devoted friends at Paris, - at Geneva, at Montpellier. Amongst these may be named in the - front rank M. de la Rive, the distinguished chemist, father of - the illustrious physicist whom we count amongst our foreign - associates. The kindnesses with which he covered my youth - contributed not a little to unite us--Faraday and myself. - With pleasure we used to recall that we made one another’s - acquaintance under the auspices of that affectionate and - helpful philosopher whose example so truly witnessed that - science does not dry up the heart’s blood. At Montpellier, - beside the hospitable hearth of Bérard, the associate of - Chaptal, doyen of our corresponding members, Faraday has left - memories equally charged with an undying sympathy which his - master could never have inspired. We admired Davy, we loved - Faraday. - -It is December 29 when the travellers leave Paris and cross the forest -of Fontainebleau. Faraday thinks he never saw a more beautiful scene -than the forest dressed in an airy garment of crystalline hoar frost. -They pass through Lyons, Montpellier, Aix, Nice, searching on the -way for iodine in the sea-plants of the Mediterranean. At the end -of January, 1814, they cross the Col de Tende over the snow at an -elevation of 6,000 feet into Italy, and find themselves in the midst -of the Carnival at Turin. They reach Genoa, and go to the house of a -chemist to make experiments on the _raia torpedo_, the electric skate, -trying to ascertain whether water could be decomposed by the electrical -discharges of these singular fishes. From Genoa they go by sea to -Lerici in an open boat, with much discomfort and fear of ship-wreck; -and thence by land to Florence. - -[Sidenote: WITH DAVY IN ITALY.] - -At Florence he goes with Davy to the Accademia del Cimento. He sees the -library, the gardens, the museum. Here is Galileo’s own telescope--a -simple tube of paper and wood, with lenses at each end--with which he -discovered Jupiter’s satellites. Here is the great burning glass of the -Grand Duke of Tuscany. And here is a numerous collection of magnets, -including one enormous loadstone supporting a weight of 150 pounds. -They make “the grand experiment of burning the diamond” in oxygen by -the sun’s heat concentrated through the Grand Duke’s burning glass. -They find the diamond to be pure carbon. Then early in April they -depart for Rome. - -From Rome Faraday wrote to his mother a long chatty letter summarising -his travels, and sending messages of kindly remembrance to his -old master Riebau and others. He tells how, in spite of political -troubles, Sir Humphry Davy’s high name has procured them free admission -everywhere, and how they have just heard that Paris has been taken by -the Allied troops. - -At Rome they witness unconvinced some attempts of Morichini to impart -magnetism to steel needles by the solar rays. They pass the Colosseum -by moonlight, making an early morning start across the Campagna, on -the road to Naples, with an armed guard for fear of brigands. Twice, -in the middle of May, they ascend Vesuvius, the second time during a -partial eruption rendered all the more vivid by the lateness of the -hour--half-past seven--at which the edge of the crater was reached. In -June they visit Terni, and note the nearly circular rainbow visible in -the spray of the cataract; and so across the Apennines to Milan. - -At Milan occurs the following entry:-- - - Friday 17th [June, 1814], Milan. Saw M. Volta, who came to Sir - H. Davy, an hale elderly man, bearing the red ribbon, and very - free in conversation. - -He does _not_ record how the ceremonious old Count, who had specially -attired himself in his Court uniform to welcome the illustrious -chemist, was horrified at the informal manners and uncourtly dress of -the tourist philosopher. - -So, travelling by Como and Domo d’Ossola, they come to Geneva, and -here remain a long time; and Faraday writes again to his mother and -to Abbott. He can even find time to discuss with the latter the -relative merits of the French and Italian languages, and the trend of -civilisation in Paris and in Rome. Twice he sends messages to Riebau. -One of his letters to Abbott, in September, contains passages of more -than transient interest:-- - - Some doubts have been expressed to me lately with respect - to the continuance of the Royal Institution; Mr. Newman can - probably give a guess at the issue of them. I have three boxes - of books, &c., there, and I should be sorry if they were lost - by the turning up of unforeseen circumstances; but I hope all - will end well (you will not read this out aloud). Remember - me to all friends, if you please. And “now for you and I to - ourselves.”... - - In passing through life, my dear friend, everyone must expect - to receive lessons, both in the school of prosperity and in - that of adversity; and, taken in a general sense, these schools - do not only include riches and poverty, but everything that - may cause the happiness and pleasure of man, and every feeling - that may give him pain. I have been in at the door of both - these schools; nor am I so far on the right hand at present - that I do not get hurt by the thorns on my left. With respect - to myself, I have always perceived (when, after a time, I saw - things more clearly) that those things which at first appeared - as misfortunes or evils ultimately were actually benefits, - and productive of much good in the future progress of things. - Sometimes I compared them to storms and tempests, which cause a - temporary disarrangement to produce permanent good; sometimes - they appeared to me like roads--stony, uneven, hilly, and - uncomfortable, it is true--but the only roads to a good beyond - them; and sometimes I said they were clouds which intervened - between me and the sun of prosperity, but which I found were - refreshing, reserving to me that tone and vigour of mind which - prosperity alone would enervate and ultimately destroy.... - - [Sidenote: HINTS OF DISCOMFORT.] - - You talk of travelling, and I own the word is seducing, but - travelling does not secure you from uneasy circumstances. I - by no means intend to deter you from it; for though I should - like to find you at home when I come home, and though I know - how much the loss would be felt by our friends, yet I am aware - that the fund of knowledge and of entertainment opened would - be almost infinite. But I shall set down a few of my own - thoughts and feelings, &c., in the same circumstances. In the - first place, then, my dear B., I fancy that when I set my foot - in England I shall never take it out again; for I find the - prospect so different from what it at first appeared to be, - that I am certain, if I could have foreseen the things that - have passed, I should never have left London. In the second - place, enticing as travelling is--and I appreciate fully its - advantages and pleasures--I have several times been more - than half decided to return hastily home; but second thoughts - have still induced me to try what the future may produce, and - now I am only retained by the wish of improvement. I have - learned just enough to perceive my ignorance, and, ashamed of - my defects in everything, I wish to seize the opportunity of - remedying them. The little knowledge I have gained in languages - makes me wish to know more of them, and the little I have - seen of men and manners is just enough to make me desirous of - seeing more; added to which, the glorious opportunity I enjoy - of improving in the knowledge of chemistry and the sciences - continually determines me to finish this voyage with Sir - Humphry Davy. But if I wish to enjoy those advantages, I have - to sacrifice much; and though those sacrifices are such as an - humble man would not feel, yet I cannot quietly make them. - Travelling, too, I find, is almost inconsistent with religion - (I mean modern travelling), and I am yet so old-fashioned as - to remember strongly (I hope perfectly) my youthful education; - and upon the whole, _malgré_ the advantages of travelling, it - is not impossible but that you may see me at your door when you - expect a letter. - - You will perceive, dear B., that I do not wish you hastily - to leave your present situation, because I think that a - hasty change will only make things worse. You will naturally - compare your situation with others you see around you, and - by this comparison your own will appear more sad, whilst the - others seem brighter than in truth they are; for, like the two - poles of a battery, the ideas of each will become exalted by - approaching them. But I leave you, dear friend, to act in this - case as your judgment may direct, hoping always for the best. - - * * * * * - - Sir Humphry works often on iodine, and has lately been making - experiments on the prismatic spectrum at M. Pictet’s. They - are not yet perfected, but from the use of very delicate air - thermometers, it appears that the rays producing most heat are - certainly out of the spectrum and beyond the red rays. Our time - has been employed lately in fishing and shooting; and many a - quail has been killed in the plains of Geneva, and many a - trout and grayling have been pulled out of the Rhone. - - * * * * * - - I need not say, dear Ben, how perfectly I am yours, - - M. FARADAY. - - -[Sidenote: ARISTOCRATIC HAUTEUR.] - -This letter reveals, what the diary of travel so scrupulously hides, -the existence of circumstances which were hardly tolerable in Faraday’s -position. To make the reference intelligible it should be remembered -that Davy, who had come up to London in 1801 as a raw youth, of immense -ability but very uncouth exterior, had developed into a fashionable -person, had become the idol of the hour, had married a very wealthy -widow, had been knighted, and had given himself up very largely to the -pursuits of fashionable society and to the company of the aristocratic -_beau monde_. Lady Davy accompanied Sir Humphry in this Continental -tour; and though Faraday had been taken with them as secretary and -scientific assistant, it would seem that he had not always been -treated with the respect due to one in that position. The above letter -evidently disquieted Abbott, for he wrote back to Faraday to inquire -more closely into his personal affairs, telling him he was sure he -was not happy, and asking him to share his difficulties. Faraday, who -was now back in Rome, replied in January in a long letter of twelve -pages,[9] which he says he had intended to fill with an account of -the waterfalls he had seen, but which gives instead a detailed account -of his vexations. He had, he said, written his former letter when -in a ruffled state of mind. He now gives the explanation. Before, -however, this letter could reach Abbott, the latter had written yet -more urgently to know what was the matter. To this Faraday replied -on February 23rd. As this shorter letter summarises the previous one -it may be given here. Both are printed in Bence Jones’s “Life and -Letters”:-- - - Rome, February 23, 1815. - - DEAR B----,--In a letter of above twelve pages I gave answers - to your question respecting my situation. It was a subject - not worth talking about, but I consider your inquiries as so - many proofs of your kindness and the interest you take in my - welfare, and I thought the most agreeable thanks I could make - you would be to answer them. The same letter also contained a - short account of a paper written by Sir Humphry Davy on ancient - colours, and some other miscellaneous matters. - - [Sidenote: SECRET OF MORTIFICATION.] - - I am quite ashamed of dwelling so often on my own affairs, - but as I know you wish it, I shall briefly inform you of my - situation. I do not mean to employ much of this sheet of paper - on the subject, but refer you to the before-mentioned long - letter for clear information. It happened a few days before we - left England, that Sir H.’s valet declined going with him, and - in the short space of time allowed by circumstances another - could not be got. Sir H. told me he was very sorry, but that, - if I would do such things as were absolutely necessary for him - until he got to Paris, he should there get another. I murmured, - but agreed. At Paris he could not get one. No Englishmen were - there, and no Frenchman fit for the place could talk English - to me. At Lyons he could not get one; at Montpellier he could - not get one; nor at Genoa, nor at Florence, nor at Rome, nor - in all Italy; and I believe at last he did not wish to get one: - and we are just the same now as we were when he left England. - This of course throws things into my duty which it was not - my agreement, and is not my wish, to perform, but which are, - if I remain with Sir H., unavoidable. These, it is true, are - very few; for having been accustomed in early years to do for - himself, he continues to do so at present, and he leaves very - little for a valet to perform; and as he knows that it is not - pleasing to me, and that I do not consider myself as obliged - to do them, he is always as careful as possible to keep those - things from me which he knows would be disagreeable. But Lady - Davy is of another humour. She likes to show her authority, - and at first I found her extremely earnest in mortifying me. - This occasioned quarrels between us, at each of which I gained - ground, and she lost it; for the frequency made me care nothing - about them, and weakened her authority, and after each she - behaved in a milder manner. Sir H. has also taken care to get - servants of the country, ycleped _lacquais de place_, to do - everything she can want, and now I am somewhat comfortable; - indeed, at this moment I am perfectly at liberty, for Sir H. - has gone to Naples to search for a house or lodging to which we - may follow him, and I have nothing to do but see Rome, write my - journal, and learn Italian. - - But I will leave such an unprofitable subject, and tell you - what I know of our intended route. For the last few weeks - it has been very undecided, and at this moment there is no - knowing which way we shall turn. Sir H. intended to see Greece - and Turkey this summer, and arrangements were half made for - the voyage; but he has just learned that a quarantine must be - performed on the road there, and to do this he has an utter - aversion, and that alone will perhaps break up the journey. - - * * * * * - - Since the long letter I wrote you, Sir H. has written two short - papers for the Royal Society--the first on a new solid compound - of iodine and oxygen, and the second a new gaseous compound of - chlorine and oxygen, which contains four times as much oxygen - as euchlorine. - - The discovery of these bodies contradicts many parts of - Gay-Lussac’s paper on iodine, which has been very much vaunted - in these parts. The French chemists were not aware of the - importance of the subject until it was shown to them, and now - they are in haste to reap all the honours attached to it; but - their haste opposes their aim. They reason theoretically, - without demonstrating experimentally, and errors are the result. - - * * * * * - - I am, my dear Friend, yours ever and faithfully, - M. FARADAY. - - -The equivocal position thus forced upon Faraday by the _hauteur_ of -Lady Davy nearly caused a _contretemps_ during the stay at Geneva, -which lasted from the end of June, 1814, to about the middle of -September. Bence Jones’s account, derived from Faraday himself, is -as follows:--Professor G. de la Rive, undazzled by the brilliancy of -Davy’s reputation, was able to see the true worth of his assistant. -Davy was fond of shooting, and Faraday, who accompanied them, used to -load Davy’s gun for him, while De la Rive loaded his own. Entering -into conversation with Faraday, De la Rive was astonished to find that -the intelligent and charming young man whom he had taken hitherto -for a domestic was really _préparateur de laboratoire_ in the Royal -Institution. This led him to place Faraday, in one respect, on an -equality with Davy. Whilst they were staying in his house, he wished -them to dine together at his table. Davy, it is said, declined, because -Faraday acted in some things as his servant. De la Rive expressed his -feelings strongly, and ordered dinner in a separate room for Faraday. -A rumour spread years after that De la Rive gave a dinner in Faraday’s -honour: this is not so, however. - -[Sidenote: VISIT TO GENEVA.] - -Of that Geneva visit Faraday says, in 1858, to M. A. de la Rive:-- - - I have some such thoughts (of gratitude) even as regards your - own father, who was, I may say, the first who personally at - Geneva, and afterwards by correspondence, encouraged and by - that sustained me. - -This correspondence, which began with the father and was continued with -the son, lasted altogether nearly fifty years. - -From Geneva the travellers went northward, by Lausanne, Vevay, Bern, -Zürich, and Schaffhausen, across Baden and Würtemburg to Munich. After -visiting this and other German towns, they crossed Tyrol southwards to -Vicenza, halting in the neighbourhood of the Pietra Mala to collect the -inflammable gas which there rises from the soil. They spent a day in -Padua, and three days in Venice; and on by Bologna to Florence, where -Davy completed his analysis of the gas collected at Pietra Mala. Early -in November they were again in Rome. He writes once and again to his -mother, while his anxiety about the Royal Institution makes him send -inquiries to Abbott as to what is going to happen there, and to charge -him, “if any change should occur in Albemarle Street,” not to forget -his books which are lying there. “I prize them now more than ever.” - -To his former master, Riebau, he wrote from Rome as follows:-- - - Rome, Jan. 5th, 1815. - - HONOURED SIR, - - It is with very peculiar but very pleasing and indeed - flattering sentiments that I commence a letter intended for - you, for I esteem it as a high honour that you should not only - allow but even wish me to write to you. During the whole of - the short eight years that I was with you, Sir, and during - the year or two that passed afterwards before I left England, - I continually enjoyed your goodness and the effects of it; - and it is gratifying to me in the highest degree to find that - even absence has not impaired it, and that you are willing to - give me the highest proof of (allow me to say) friendship that - distance will admit. I have received both the letters that you - have wrote to me, Sir, and consider them as far from being the - least proofs of your goodwill and remembrance of me. Allow - me to thank you humbly but sincerely for these and all other - kindness, and I hope that at some future day an opportunity - will occur when I can express more strongly my gratitude. - - I beg leave to return a thousand thanks to my kind Mistress, - to Mr. and Mrs. Paine and George for their remembrances, and - venture to give mine with respect in return. I am very glad to - hear that all are well. I am very much afraid you say too much - of me to Mr. Dance, Mr. Cosway, Mrs. Udney, etc., for I feel - unworthy of what you have said of me formerly, and what you - may say now. Since I have left England, the experience I have - gained in more diversified and extended life, and the knowledge - I have gained of what is to be learned and what others know, - have sufficiently shown me my own ignorance, the degree in - which I am surpassed by all the world, and my want of powers; - but I hope that at least I shall return home with an addition - to my self-knowledge. When speaking of those who are so much - my superiors, as Mr. Dance, Mr. Cosway, and Mrs. Udney, etc., - I feel a continual fear that I should appear to want respect, - but the manner in which you mention their names in your letter - emboldens me to beg that you will give my humblest respects - to those honored persons, if, and only if (I am afraid of - intruding) they should again speak of me to you. Mr. Dance’s - kindness claims my gratitude, and I trust that my thanks, the - only mark that I can give, will be accepted. - - [Sidenote: BOOKS AND BOOKSELLERS.] - - Since I have been abroad, my old profession of books has - oftentimes occurred to my mind and been productive of much - pleasure. It was my wish at first to purchase some useful book - at every large town we came to, but I found my stock increase - so fast that I was obliged to alter my plan and purchase only - at Capital Cities. The first books that I wanted were grammars - and dictionaries, but I found few places like London where I - could get whatever I wanted. In France (at the time we were - there) English books were very scarce, and also English and - French books; and a French grammar for an Englishman was a - thing difficult to find. Nevertheless the shops appeared well - stocked with books in their own language, and the encouragement - Napoleon gave to Arts and Sciences extended its influence even - to the printing and binding of books. I saw some beautiful - specimens in both these branches at the Bibliothèque Impériale - at Paris, but I still think they did not exceed or even equal - those I had seen in London before. We have as yet seen very - little of Germany, having passed rapidly through Switzerland - and stopping but a few days at Munich, but that little gave - me a very favorable idea of the Booksellers’ shops. I got an - excellent English and German dictionary immediately I asked for - it, and other books I asked for I found were to be had, but E. - and G. Grammars were scarce, owing to the little communication - between the two Empires, and the former power of the French - in Germany. Italy I have found the country furnished with - the fewest means--if books are the means of disseminating - knowledge, and even Venice which is renowned for Printing - appeared to me bare and little worthy of its character. It is - natural to suppose that the great and most estimable use of - printing is to produce those books which are in most general - use and which are required by the world at large; it is those - books which form this branch of trade, and consequently every - shop in it gives an account of the more valuable state of the - art (_i.e._) the use made of it. In Italy there are many - books, and the shelves of the shops there appear full, but the - books are old, or what is new have come from France; they seem - latterly to have resigned printing and to have become satisfied - with the libraries their forefathers left them. I found at - Florence an E. and I. Grammar (Veneroni’s), which does a little - credit to Leghorn; but I have searched unsuccessfully at Rome, - Naples, Milan, Bologna, Venice, Florence, and in every part of - Italy for and E. and I. Dictionary, and the only one I could - get was Rollasetti in 8vo. E. F. and I. A circumstance still - more singular is the want of bibles; even at Rome, the seat of - the Roman Catholic faith, a bible of moderate size is not to - be found, either Protestant or Catholic. Those which exist are - large folios or 4tos and in several volumes, interspersed with - the various readings and commentaries of the fathers, and they - are in the possession of the Priests and religious professors. - In all shops at Rome where I ask for a small pocket bible the - man seemed afraid to answer me, and some Priest in the shop - looked at me in a very inquisitive way. - - I must now, Kind Sir, put an end to this letter, which I fear - you will think already too long. I beg you will have the - goodness to send to my Mother and say I am well, and give my - duty to her and my love to my brother and sisters. I have - wrote four or five times lately from Rome to various friends. - Remember me, if you please, to Mr. Kitchen, and others who may - enquire after me. I thank you for your concluding wishes and - am, Sir, - - Your most dutifully, - FARADAY. - - -To his sisters he wrote also. To the elder, on the Church festivals, -the Carnival, and the ruins of the Colosseum. To the younger, on the -best way of learning French. His diary is full of the Carnival, the -foolishness of which afforded him much amusement. He witnessed the -horse-races in the Corso, went four times to masked balls, where his -boyish love of uproarious fun broke out beyond restraint, for to the -last one he went disguised in a night-gown and night-cap. Between -gaieties in the evenings and chemical experiments with Davy in the -day, his time must have been pretty fully occupied. They had had the -intention of going on to Greece and Turkey, but owing to dread of -quarantine these projects were abandoned, and at the end of February, -1815, they moved southwards to Naples. Here is a characteristic entry:-- - - Tuesday, March 7th.--I heard for news that Bonaparte was again - at liberty. Being no politician, I did not trouble myself much - about it, though I suppose it will have a strong influence on - the affairs of Europe. - -He went with Sir Humphry to explore Monte Somma, and ventured to make -another ascent of the cone of Vesuvius, with the gratification of -finding the crater in much greater activity than during the visits of -the preceding year. - -[Sidenote: THE END OF THE TOUR.] - -Then, for reasons not altogether clear, the tour was suddenly cut -short. Naples was left on March 21st, Rome on 24th, Mantua was passed -on 30th. Tyrol was recrossed, Germany traversed by Stuttgardt, -Heidelberg, and Cologne. Brussels was reached on 16th April, whence -London was regained _viâ_ Ostend and Deal. A letter written from -Brussels to his mother positively overflows with the joy of expected -return. He does not want his mother to be inquiring at Albemarle Street -as to when he is expected:-- - - You may be sure that my first moments will be in your company. - If you have opportunities, tell some of my dearest friends, - but do not tell everybody--that is, do not trouble yourself to - do it. I am of no consequence except to a few, and there are - but a few that are of consequence to me, and there are some - whom I should like to be the first to tell myself--Mr. Riebau - for one. However, let A. know, if you can... - - Adieu till I see you, dearest Mother; and believe me ever your - affectionate and dutiful son, - - M. FARADAY. - - [P.S.] ’Tis the shortest and (to me) the sweetest letter I ever - wrote you. - -A fortnight after his return to London, Faraday was re-engaged, at -a salary of thirty shillings a week, at the Royal Institution as -assistant in the laboratory and mineralogical collection. He returned -to the scene of his former labours; but with what widened ideas! He -had had eighteen months of daily intercourse with the most brilliant -chemist of the age. He had seen and conversed with Ampère, Arago, -Gay-Lussac, Chevreul, Dumas, Volta, De la Rive, Biot, Pictet, De -Saussure, and De Stael. He had formed a lasting friendship with more -than one of these. He had dined with Count Rumford, the founder of -the Royal Institution. He had gained a certain mastery over foreign -tongues, and had seen the ways of foreign society. Though it was many -years before he again quitted England for a foreign tour, he cherished -the most lively recollection of many of the incidents that had befallen -him. - - - - -CHAPTER II. - -LIFE AT THE ROYAL INSTITUTION. - - -Amongst the scientific societies of Great Britain, the Royal -Institution of London occupies a conspicuous place. It has had many -imitators in its time, yet it remains unique. A “learned society” -it may claim to be, in the sense that it publishes scientific -transactions, and endeavours to concentrate within itself and promote -the highest science, within a certain range of subjects. In some -respects it resembles a college; for it appoints professors, and -provides them with space, appliances, and materials for research, and a -theatre wherein to lecture. For its members it provides a comfortable, -well-stocked library, and a reading-room where daily and periodic -journals may be consulted. But it has achieved a reputation far in -excess of any it would have held, had that reputation depended solely -on its publications, or on the numerical strength of its membership. - -Founded in the year 1799 by that erratic genius Count Rumford, as a -sort of technical school,[10] it would speedily have come to an end -had not others stepped in to develop it in new ways. From the certain -ruin which seemed impending in 1801, it was saved by the appearance -upon the scene of the brilliant youth Humphry Davy, whose lectures -made it for ten years the resort of fashion. In 1814 it was again in -such low water that Faraday, travelling on the Continent at that time -as amanuensis to Sir Humphry, was every month expecting to hear of its -collapse. Until about 1833, when the two Fullerian Professorships were -founded, it was continually in financial difficulties. The persistent -and extraordinary efforts made by Faraday from 1826 to 1839, and -the reputation of the place which accrued by his discoveries, were -beyond all question its salvation from ruin. When it was founded it -was located in two private houses in Albemarle Street, then regarded -as quite out of town, if not almost suburban; the premises being -altered and an entrance hall with staircase added. A little later the -lecture-theatre, much as it still exists, was constructed. The exterior -at first remained unchanged. The stucco pilasters of Grecian style, -which give it its air of distinction, were not erected until 1838. -The fine rooms of the Davy-Faraday laboratory at the south end were -only added in 1896 by the liberality of Mr. Ludwig Mond. Besides the -laboratories for research in physical chemistry, which have thus been -associated with the older part of the Institution, additional rooms for -the library have been provided in this munificent gift to science. The -older laboratories of the Institution, though they retain some features -from Rumford’s time, have been considerably remodelled. The old rooms -where Davy, Young, Brande, Faraday, Frankland, and Tyndall conducted -their researches are still in existence; but the chief laboratory was -reconstructed in 1872 in Tyndall’s time; and it has been quite recently -enlarged and reconstructed to accommodate the heavy machinery required -in Professor Dewar’s researches on liquid air and the properties of -bodies at low temperatures. - -The spirit of the place may be summed up very briefly. It has existed -for a century as the home of the highest kind of scientific research, -and of the best and most specialised kind of scientific lectures. -It was here that Davy first showed the electric arc lamp; that he -astonished the world by decomposing potash and producing potassium; -that he invented the safety lamp. It was here that Faraday worked and -laboured for nearly fifty years. Here that Tyndall’s investigations -on radiant heat and diamagnetism were carried on. Here that Brande, -Frankland, Odling, Gladstone, and Dewar have handed on the torch -of chemistry from the time of Davy. Professorships, of which the -educational duties are restricted to a few lectures in the year, -giving leisure and scope for research as the main duty, are not to -be found anywhere else in the British Islands; those at colleges -and universities being invariably hampered with educational and -administrative duties. - -[Sidenote: ROYAL INSTITUTION LABORATORIES.] - -As for the lectures at the Royal Institution, they may be divided under -three heads: the afternoon courses; the juvenile lectures at Christmas; -the Friday night discourses. The afternoon lectures are thrice a week -at three o’clock, and consist usually of short courses, from three -lectures to as many as twelve, by eminent scientific and literary men. -Invariably one of these courses during the season, either before or -after Easter, is given by one of the regular Professors; the remaining -lecturers are paid professional fees in proportion to the duration of -their course. The Christmas lectures, always six in number, are given, -sometimes by one of the Professors, sometimes by outside lecturers -of scientific reputation. But the Friday night discourses, given at -nine o’clock, during the season from January till June, are unique. -No fee is paid to the lecturer, save a contribution toward expenses -if applied for, and it is considered to be a distinct honour to be -invited to give such a discourse. There is no scientific man of any -original claim to distinction; no chemist, engineer, or electrician; no -physiologist, geologist, or mineralogist, during the last fifty years, -who has not been invited thus to give an account of his investigations. -Occasionally a wider range is taken, and the eminent writer of books, -dramatist, metaphysician, or musician has taken his place at the -lecture-table. The Friday night gathering is always a brilliant one. -From the _salons_ of society, from the world of politics and diplomacy, -as well as from the ranks of the learned professions and of the fine -arts, men and women assemble to listen to the exposition of the latest -discoveries or the newest advances in philosophy by the men who have -made them. Every discourse must, so far as the subject admits, be -illustrated in the best possible way by experiments, by diagrams, by -the exhibition of specimens. Not infrequently, the person invited to -give a Friday evening discourse at the Royal Institution will begin -his preparations five or six months beforehand. At least one instance -is known--the occasion being a discourse by the late Mr. Warren De la -Rue--where the preparations were begun more than a year beforehand, and -cost several hundreds of pounds. And this was to illustrate a research -already made and completed, of which the bare scientific results had -already been communicated in a memoir to the Royal Society. A mere -enumeration of the eminent men who have thus given their time and -labours to the Royal Institution would fill many pages. It is little -cause for wonder then that the lecture-theatre at Albemarle Street is -crowded week after week in the pursuit of science under conditions like -these; or that every lecturer is spurred on by the spirit of the place -to do his subject the utmost justice by the manner in which he handles -it. There are no lectures so famous, in the best sense of the word so -popular, certainly none sustained at so high a level, as the lectures -of the Royal Institution. - -[Sidenote: THE FAMOUS LECTURES.] - -But it was not always thus. Davy’s brilliant but ill-balanced genius -had drawn fashionable crowds to the morning lectures which he gave. -Brande proved to be a much more humdrum lecturer; and though with young -Faraday at his elbow he found his work of lecturing a task “on velvet,” -he was not exactly an inspiring person. During Davy’s protracted tour -abroad things had not altogether prospered, and his return was none -too soon. Faraday threw himself whole-heartedly into the work of the -Institution, not only helping as lecture assistant, but giving a hand -also in the preparation of the _Quarterly Journal of Science_, which -had been established as a kind of journal of proceedings. - -But now Faraday was to take a quiet step forward. He appears at the -City Philosophical Society in the character of lecturer. He gave -seven lectures there, in 1816, on chemistry, the fourth of them being -“On Radiant Matter.” Extracts are given from most of these lectures -in Bence Jones’s “Life and Letters of Faraday”; they show all that -love of accuracy, that philosophic suspense of judgment in matters of -hypothesis, which in after years were so characteristic of the man. - -He also kept a commonplace book filled with notes of scientific -matters, with literary excerpts, anagrams, epitaphs, algebraic puzzles, -varieties of spelling of his own name, and personal experiences, -including a poetical diatribe against falling in love, together with -the following more prosaic aphorism:-- - - What is Love?--A nuisance to everybody but the parties - concerned. A private affair which every one but those concerned - wishes to make public. - -It also includes a piece in verse, by a member of the City -Philosophical Society--a Mr. Dryden--called “Quarterly Night,” which -is interesting as embalming a portrait of the youthful Faraday as he -appeared to his comrades:-- - - Neat was the youth in dress, in person plain; - His eye read thus, _Philosopher in grain_; - Of understanding clear, reflection deep; - Expert to apprehend, and strong to keep. - His watchful mind no subject can elude, - Nor specious arts of sophists ere delude; - His powers, unshackled, range from pole to pole; - His mind from error free, from guilt his soul. - Warmth in his heart, good humour in his face, - A friend to mirth, but foe to vile grimace; - A temper candid, manners unassuming, - Always correct, yet always unpresuming. - Such was the youth, the chief of all the band; - His name well known, Sir Humphry’s right hand. - -At this date there were no evening duties at the Royal Institution, but -Faraday found his evenings well occupied, as he explains to Abbott when -rallied about his having deserted his old friend. Monday and Thursday -evenings he spent in self-improvement according to a regular plan. -Wednesdays he gave to “the Society” (_i.e._ the City Philosophical). -Saturdays he spent with his mother at Weymouth Street; leaving only -Tuesdays and Fridays for his own business and friends. - -[Sidenote: CITY PHILOSOPHICAL SOCIETY.] - -And so the busy months pass, and he gives more lectures in the privacy -of the City Society, one of them, “On some Observations on the Means -of obtaining Knowledge,” attaining the dignity of print at the hands -of Effingham Wilson, the enterprising City publisher, who a few -years later printed Browning’s “Paracelsus” and Alfred Tennyson’s -first volume, “Poems: Chiefly Lyrical.” By the time he has given -nine lectures he has gained confidence. The discourses had all been -written out beforehand, though never literally “read.” For the tenth -lecture--on Carbon--he wrote notes only. This is in July, 1817, and in -these notes he touches on a matter in which he had been very busily -aiding Sir Humphry Davy, the invention of the safety lamp. Many -of the early forms of experimental apparatus constructed, and some -of the early lamps, are still preserved in the museum of the Royal -Institution. Dr. Clanny had, in 1813, proposed an entirely closed lamp, -supplied with air from the mine, through water, by bellows. After many -experiments on explosive mixtures of gas and air, and on the properties -of flame, Davy adopted an iron-wire gauze protector for his lamp, which -was introduced into coal mining early in 1816. In Davy’s preface to -his work describing it, he says: “I am myself indebted to Mr. Michael -Faraday for much able assistance in the prosecution of my experiments.” - -[Sidenote: A RIFT WITHIN THE LUTE.] - -And well might Davy be grateful. With all his immense ability, he -was a man almost destitute of the faculties of order and method. He -had little self-control, and the fashionable dissipations which he -permitted himself lessened that little. Faraday not only kept his -experiments going, but made himself responsible for their records. He -preserved every note and manuscript of Davy’s with religious care. -He copied out Davy’s scrawled researches in a neat clear delicate -handwriting, begging only for his pains to be allowed to keep the -originals, which he bound in two quarto volumes. Faraday has been known -to remark to an intimate friend that amongst his advantages he had had -before him a model to teach him what he should avoid. But he was ever -loyal to Davy, earnest in his praise, and frank in his acknowledgment -of his debt to his master in science. Still there arose the little rift -within the lute. The safety lamp, great as was the practical advantage -it brought to the miner, is not safe in all circumstances. Davy did -not like to admit this, and would never acknowledge it. Examined before -a Parliamentary Committee as to whether under a certain condition -the safety lamp would become unsafe, Faraday admitted that this was -the case. Not even his devotion to his master would induce him to -hide the truth. He was true to himself in making the acknowledgment, -though it angered his master. One Friday evening at the Royal -Institution--probably about 1826--there was exhibited an improved Davy -lamp with a eulogistic inscription; Faraday added in pencil the words: -“The opinion of the inventor.” - -At this time he began to give private lessons in chemistry to a pupil -to whom he had been recommended by Davy. His lectures at the City -Society in Dorset Street were continued in 1818, and at the conclusion -of those on chemistry he delivered one on “Mental Inertia,” which has -been recorded at some length by Bence Jones. - -In 1818 he attended a course of lessons on oratory by the elocutionist -Mr. B. H. Smart, paying out of his slender resources half a guinea a -lesson, so anxious was he to improve himself, even in his manner of -lecturing. His notes on these lessons fill 133 manuscript pages. - -His other notes now begin to partake less of the character of -quotations and excerpts, and more of the nature of queries or problems -for solution. Here are some examples:-- - - “Do the pith balls diverge by the disturbance of electricity in - consequence of mutual induction or not?” - - “Distil oxalate of ammonia. Query, results?” - - “Query, the nature of the body Phillips burns in his spirit - lamp?” - -The Phillips here mentioned was the chemist Richard Phillips -(afterwards President of the Chemical Society), one of his City -friends, whose name so frequently occurs in the correspondence of -Faraday’s middle life. Phillips busied himself to promote the material -interests of his friend who--to use his own language--was “constantly -engaged in observing the works of Nature, and tracing the manner in -which she directs the arrangement and order of the world,” on the -splendid salary of £100 per annum. The following note in a letter to -Abbott, dated February 27, 1818, reveals new professional labours:-- - - I have been more than enough employed. We have been obliged - even to put aside lectures at the Institution; and now I am so - tired with a long attendance at Guildhall yesterday and to-day, - being subpœnaed, with Sir H. Davy, Mr. Brande, Phillips, Aikin, - and others, to give chemical information on a trial (which, - however, did not come off), that I scarcely know what I say. - -Shortly afterwards Davy again went abroad, but Faraday remained in -England. From Rome Davy wrote a note, the concluding sentence of which -shows how Faraday was advancing in his esteem:-- - - Rome: October, 1818. - - Mr. Hatchett’s letter contained praises of you which were - very gratifying to me; for, believe me, there is no one more - interested in your success and welfare than your sincere - well-wisher and friend, - - H. DAVY. - - -In the next year Davy wrote again, suggesting to Faraday that he might -possibly be asked to come to Naples as a skilled chemist to assist in -the unrolling of the Herculaneum manuscripts. In May he wrote again, -from Florence:-- - - It gives me great pleasure to hear that you are comfortable at - the Royal Institution, and I trust that you will not only do - something good and honourable for yourself, but likewise for - science. - - I am, dear Mr. Faraday, always your sincere friend and - well-wisher, - - H. DAVY. - - -The wish that Davy expressed that Faraday might “do something” -for himself and likewise for science was destined soon to come to -fulfilment. But in the case of one who had worked so closely and had -been so intimately associated as an assistant, it must necessarily be -no easy matter always to draw a distinction between the work of the -master and that of the assistant. Ideas suggested by one might easily -have occurred to the other, when their thoughts had so long been -directed to the same ends. And so it proved. - -[Sidenote: BEGINS ORIGINAL RESEARCHES.] - -Reference to Chapter III. will show that already, beginning in 1816 -with a simple analysis of caustic lime for Sir Humphry Davy, Faraday -had become an active worker in the domain of original research. -The fascination of the quest of the unknown was already upon him. -While working with and for Davy on the properties of flame and its -non-transmission through iron gauze, in the investigation of the -safety lamp, other problems of a kindred nature had arisen. One of -these, relating to the flow of gases through capillary tubes, Faraday -had attacked by himself in 1817. The subject formed one of the six -original papers which he published that year. In the next two years -he contributed in all no fewer than thirty-seven papers or notes to -the _Quarterly Journal of Science_. In 1819 began a long research on -steel which lasted over the year 1820. He had already given evidence -of that dislike of half-truths, that aversion for “doubtful knowledge” -which marked him so strongly. He had exposed, with quiet but unsparing -success, the emptiness of the claim made by an Austrian chemist to have -discovered a new metal, “Sirium,” by the simple device of analysing -out from the mass all the constituents of known sorts, leaving -behind--nothing. - -[Sidenote: HE FALLS IN LOVE.] - -And now, Faraday being twenty-nine years of age, a new and -all-important episode in his life occurred. Amongst the members of the -little congregation which met on Sundays at Paul’s Alley, Red Cross -Street, was a Mr. Barnard, a working silversmith of Paternoster Row, -an elder in the Sandemanian body. He had two sons, Edward Barnard, a -friend of Faraday’s, and George, who became a well-known water-colour -artist; and three daughters; one who was already at this time married; -Sarah, now twenty-one years of age; and Jane, who was still younger. -Edward had seen in Faraday’s note-book those boyish tirades against -falling in love, and had told his sister Sarah of them. Nevertheless, -in spite of all such misogynistic fancies, Faraday woke up one day to -find that the large-eyed, clear-browed girl had grown to a place in his -heart that he had thought barred against the assaults of love. She -asked him on one occasion to show her the rhymes against love in his -note-book. In reply he sent her the hitherto unpublished poem:-- - - R. I. - Oct. 11th, 1819. - - You ask’d me last night for the lines which I penn’d, - When, exulting in ignorance, tempted by pride, - I dared torpid hearts and cold breasts to commend, - And affection’s kind pow’r and soft joys to deride. - - If you urge it I cannot refuse your request: - Though to grant it will punish severely my crime: - But my fault I repent, and my errors detest; - And I hoped to have shown my conversion in time. - - Remember, our laws in their mercy decide - That no culprit be forced to give proof of his deed: - They protect him though fall’n, his failings they hide, - And enable the wretch from his crimes to receed (_sic_). - - The principle’s noble! I need not urge long - Its adoption; then turn from a judge to a friend. - Do not ask for the proof that I once acted wrong, - But direct me and guide me the way to amend. - - M. F. - - -What other previous passages between them are hinted at in the letter -which he sent her, is unknown; but on July 5, 1820, he wrote:-- - - Royal Institution. - - You know me as well or better than I do myself. You know - my former prejudices, and my present thoughts--you know my - weaknesses, my vanity, my whole mind; you have converted me - from one erroneous way, let me hope you will attempt to correct - what others are wrong. - - * * * * * - - Again and again I attempt to say what I feel, but I cannot. - Let me, however, claim not to be the selfish being that wishes - to bend your affections for his own sake only. In whatever way - I can best minister to your happiness either by assiduity or by - absence, it shall be done. Do not injure me by withdrawing your - friendship, or punish me for aiming to be more than a friend by - making me less; and if you cannot grant me more, leave me what - I possess, but hear me. - -Sarah Barnard showed the letter to her father. She was young, and -feared to accept her lover. All her father would say by way of counsel -was that love made philosophers say many foolish things. The intensity -of Faraday’s passion proved for the time a bar to his advance. Fearing -lest she should be unable to return it with equal force, Miss Barnard -shrank from replying. To postpone an immediate decision, she went away -with her sister, Mrs. Reid, to Ramsgate. Faraday followed to press his -suit, and after several happy days in her company, varied with country -walks and a run over to Dover, he was able to say: “Not a moment’s -alloy of this evening’s happiness occurred. Everything was delightful -to the last moment of my stay with my companion, because she was so.” - -Of the many letters that Faraday wrote to his future wife a number have -been preserved. They are manly, simple, full of quiet affection, but -absolutely free from gush or forced sentiment of any kind. Extracts -from several of them are printed by Bence Jones. One of these, written -early in 1821, runs as follows:-- - - I tied up the enclosed key with my books last night, and make - haste to return it lest its absence should occasion confusion. - If it has, it will perhaps remind you of the disorder I must be - in here also for the want of a key--I mean the one to my heart. - However, I know where my key is, and hope soon to have it here, - and then the Institution will be all right again. Let no one - oppose my gaining possession of it when unavoidable obstacles - are removed. - - Ever, my dear girl, one who is perfectly yours, - M. FARADAY. - - -Faraday obtained leave of the managers to bring his wife to live in his -rooms at the Institution; and in May, 1821, his position was changed -from that of lecture assistant to that of superintendent of the house -and laboratory. In these changes Sir Humphry Davy gave him willing -assistance. But his salary remained £100 a year. - -Obstacles being now removed, Faraday and Miss Barnard were married on -June 12. Few persons were asked to the wedding, for Faraday wished it -to be “just like any other day.” “There will,” he wrote, “be no bustle, -no noise, no hurry ... it is in the heart that we expect and look for -pleasure.” - -[Sidenote: A HAPPY MARRIAGE.] - -His marriage, though childless, was extremely happy. Mrs. Faraday -proved to be exactly the true helpmeet for his need; and he loved her -to the end of his life with a chivalrous devotion which has become -almost a proverb. Little indications of his attachment crop up in -unexpected places in his subsequent career; but as with his religious -views so with his domestic affairs, he never obtruded them upon others, -nor yet shrank from mentioning them when there was cause. Tyndall, -in after years, made the intensity of Faraday’s attachment to his -wife the subject of a striking simile: “Never, I believe, existed a -manlier, purer, steadier love. Like a burning diamond, it continued to -shed, for six and forty years, its white and smokeless glow.” - -In his diploma-book, now in possession of the Royal Society, in which -he carefully preserved all the certificates, awards, and honours -bestowed upon him by academies and universities, there may be found on -a slip inserted in the volume this entry:-- - - 25th January, 1847. - - Amongst these records and events, I here insert the date of one - which, as a source of honour and happiness, far exceeds the - rest. We were _married_ on June 12, 1821. - - M. FARADAY. - - -And two years later, in the autobiographical notes he wrote:-- - - On June 12, 1821, he married--an event which more than any - other contributed to his earthly happiness and healthful state - of mind. The union has continued for twenty-eight years, and - has nowise changed, except in the depth and strength of its - character. - -When near the close of his life, he presented to the Royal Institution -the bookcase with the volumes of notes of Davy’s lectures and of books -bound by himself, the inscription recorded that they were the gift of -“Michael _and_ Sarah Faraday.” - -Every Saturday evening he used to take his wife to her father’s -house at Paternoster Row, so that on Sunday they should be nearer to -the chapel at Paul’s Alley. And in after years, when he was away on -scientific work, visiting lighthouses, or attending meetings of the -British Association, he always tried to return for the Sunday. - -A letter from Liebig in 1844 (see p. 225) gives one of the very few -glimpses of contemporary date of the impression made by Mrs. Faraday -upon others. - -One month after his marriage Faraday made his profession of faith -before the Sandemanian church, to which his wife already belonged, and -was admitted a member. To his religious views, and his relations to the -body he thus formally joined, reference will be found later. - -[Sidenote: FIRST ELECTRICAL DISCOVERY.] - -Faraday now settled down to a routine life of scientific work. His -professional reputation was rising, and his services as analyst -were being sought after. But in the midst of this he was pursuing -investigations on his own account. In the late summer of this year -he made the discovery of the electro-magnetic rotations described in -Chapter III.--his first important piece of original research--and -had in consequence a serious misunderstanding with Dr. Wollaston. On -September 3rd, working with George Barnard in the laboratory, he saw -the electric wire for the first time revolve around the pole of the -magnet. Rubbing his hands as he danced around the table with beaming -face, he exclaimed: “There they go! there they go! we have succeeded -at last.” Then he gleefully proposed that they should wind up the day -by going to one of the theatres. Which should it be? “Oh, to Astley’s, -to see the horses.” And to Astley’s they went. On Christmas Day he -called his young wife to see something new: an electric conducting-wire -revolving under the influence of the magnetism of the earth alone. -He also read two chemical papers at the Royal Society, announcing new -discoveries; one of them in conjunction with his friend Phillips. In -July, 1822, he took his wife and her mother to Ramsgate, whilst he went -off with Phillips to Swansea to try a new process in Vivian’s copper -works. During this enforced parting, Faraday wrote his wife three -letters from which the following are extracts:--- - -[Sidenote: “A MERE LOVE-LETTER.”] - - (July 21, 1822). - - I perceive that if I give way to my thoughts, I shall write you - a mere love-letter, just as usual, with not a particle of news - in it: to prevent which I will constrain myself to a narrative - of what has happened since I left you up to the present time, - and then indulge my affection. - - Yesterday was a day of events--little, but pleasant. I went in - the morning to the Institution, and in the course of the day - analysed the water, and sent an account of it to Mr. Hatchett. - Mr. Fisher I did not see. Mr. Lawrence called in, and behaved - with his usual generosity. He had called in the early part of - the week, and, finding that I should be at the Institution on - Saturday only, came up, as I have already said, and insisted - on my accepting two ten-pound bank-notes for the information - he professed to have obtained from me at various times. Is not - this handsome? The money, as you know, could not have been at - any time more acceptable; and I cannot see any reason, my dear - love, why you and I should not regard it as another proof, - among many, that our trust should without a moment’s reserve be - freely reposed on Him who provideth all things for His people. - Have we not many times been reproached, by such mercies as - these, for our caring after food and raiment and the things - of this world? On coming home in the evening, _i.e._, coming - to Paternoster Row home, I learned that Mr. Phillips had seen - C., and had told her we should not leave London until Monday - evening. So I shall have to-morrow to get things ready in, - and I shall have enough to do. I fancy we are going to a large - mansion and into high company, so I must take more clothes. - Having the £20, I am become bold.... - - And now, how do my dear wife and mother do? Are you - comfortable? are you happy? are the lodgings convenient, and - Mrs. O. obliging? Has the place done you good? Is the weather - fine? Tell me all things as soon as you can. I think if you - write directly you get this it will be best, but let it be a - long letter. I do not know when I wished so much for a long - letter as I do from you now. You will get this on Tuesday, and - any letter from you to me cannot reach Swansea before Thursday - or Friday--a sad long time to wait. Direct to me, Post Office, - Swansea; or perhaps better, to me at -- Vivian Esq., Marino, - near Swansea, South Wales.... - - And now, my dear girl, I must set business aside. I am tired - of the dull detail of things, and want to talk of love to you; - and surely there can be no circumstances under which I can have - more right. The theme was a cheerful and delightful one before - we were married, but it is doubly so now. I now can speak, not - of my own heart only, but of both our hearts. I now speak, not - with any doubt of the state of your thoughts, but with the - fullest conviction that they answer to my own. All that I can - now say warm and animated to you, I know that you would say to - me again. The excess of pleasure which I feel in knowing you - mine is doubled by the consciousness that you feel equal joy in - knowing me yours. - -[Sidenote: FROM HUSBAND TO WIFE.] - - Marino: Sunday, July 28, 1822. - - MY DEARLY BELOVED WIFE,--I have just read your letter again, - preparatory to my writing to you, that my thoughts might be - still more elevated and quickened than before. I could almost - rejoice at my absence from you, if it were only that it has - produced such an earnest and warm mark of affection from you - as that letter. Tears of joy and delight fell from my eyes on - its perusal. I think it was last Sunday evening, about this - time, that I wrote to you from London; and I again resort to - this affectionate conversation with you, to tell you what has - happened since the letter which I got franked from this place - to you on Thursday I believe. - - * * * * * - - We have been working very hard here at the copper works, and - with some success. Our days have gone on just as before. A walk - before breakfast; then breakfast; then to the works till four - or five o’clock, and then home to dress, and dinner. After - dinner, tea and conversation. I have felt doubly at a loss - to-day, being absent from both the meeting and you. When away - from London before, I have had you with me, and we could read - and talk and walk; to-day I have had no one to fill your place, - so I will tell you how I have done. There are so many here, and - their dinner so late and long, that I made up my mind to avoid - it, though, if possible, without appearing singular. So, having - remained in my room till breakfast time, we all breakfasted - together, and soon after Mr. Phillips and myself took a walk - out to the Mumbles Point, at the extremity of this side of - the bay. There we sat down to admire the beautiful scenery - around us, and, after we had viewed it long enough, returned - slowly home. We stopped at a little village in our way, called - Oystermouth, and dined at a small, neat, homely house about - one o’clock. We then came back to Marino, and after a little - while again went out--Mr. Phillips to a relation in the town, - and myself for a walk on the sands and the edge of the bay. I - took tea in a little cottage, and, returning home about seven - o’clock, found them engaged at dinner, so came up to my own - room, and shall not see them again to-night. I went down for a - light just now, and heard them playing some sacred music in the - drawing-room; they have all been to church to-day, and are what - are called regular people. - - The trial at Hereford is put off for the present, but yet we - shall not be able to be in town before the end of this week. - Though I long to see you, I do not know when it will be; - but this I know, that I am getting daily more anxious about - you. Mr. Phillips wrote home to Mrs. Phillips from here even - before I did--_i.e._ last Wednesday. This morning he received - a letter from Mrs. Phillips (who is very well) desiring him - to ask me for a copy of one of my letters to you, that he may - learn to write love-letters of sufficient length. He laughs at - the scolding, and says that it does not hurt at a distance.... - - It seems to me so long since I left you that there must have - been time for a great many things to have happened. I expect to - see you with such joy when I come home that I shall hardly know - what to do with myself. I hope you will be well and blooming, - and animated and happy, when you see me. I do not know how we - shall contrive to get away from here. We certainly shall not - have concluded before Thursday evening, but I think we shall - endeavour earnestly to leave this place on Friday night, in - which case we shall get home late on Saturday night. If we - cannot do that, as I should not like to be travelling all day - on Sunday, we shall probably not leave until Sunday night; but - I think the first plan will be adopted, and that you will not - have time to answer this letter. I expect, nevertheless, an - answer to my last letter--_i.e._ I expect that my dear wife - will think of me again. Expect here means nothing more than - I trust and have a full confidence that it will be so. My - kind girl is so affectionate that she would not think a dozen - letters too much for me if there were time to send them, which - I am glad there is not. - - Give my love to our mothers as earnestly as you would your own, - and also to Charlotte or John, or any such one that you may - have with you. I have not written to Paternoster Row yet, but - I am going to write now, so that I may be permitted to finish - this letter here. I do not feel quite sure, indeed, that the - permission to leave off is not as necessary from my own heart - as from yours. - - With the utmost affection--with perhaps too much--I am, my dear - wife, my Sarah, your devoted husband, - - M. FARADAY. - - -Faraday’s next scientific success was the liquefaction of chlorine -(see Chapter III., p. 93). This discovery, which created much interest -in the scientific world, was the occasion of a serious trouble with -Sir Humphry Davy; for doubtless Davy was annoyed that he had left such -a simple experiment to a mere assistant. Writing on the matter years -after, Faraday said:-- - - When my paper was written, it was, according to a custom - consequent upon our relative positions, submitted to Sir - H. Davy (as were all my papers for the “Philosophical - Transactions” up to a much later period), and he altered it as - he thought fit. This practice was one of great kindness to me, - for various grammatical mistakes and awkward expressions were - from time to time thus removed, which might else have remained. - -In point of fact, Davy on this occasion added a note (which was duly -printed) saying precisely how far he had any share in suggesting the -experiment, but in no wise traversing any of Faraday’s claims. Although -he thus acted generously to the latter, there can be no question -that he began to be seriously jealous of Faraday’s rising fame. The -matter was the more serious because some who did not have a nice -appreciation of the circumstances chose to rake up a charge which had -been raised two years before against Faraday by some of Dr. Wollaston’s -friends--in particular by Dr. Warburton--about the discovery of the -electro-magnetic rotations, a charge which Faraday’s straightforward -action and Wollaston’s frank satisfaction ought to have dissipated -for ever. And all this was doubly aggravating because Faraday was now -expecting to be proposed as a candidate for the Fellowship of the Royal -Society, of which Sir Humphry was President. - -[Sidenote: PROPOSED FOR THE FELLOWSHIP.] - -At that time, as now, the proposal paper or “certificate” of a -candidate for election must be presented, signed by a number of -influential Fellows. Faraday’s friend Phillips took in hand the -pleasant task of drawing up this certificate and of collecting -the necessary signatures. The rule then was that the certificate -so presented must be read out at ten successive meetings of the -Society; after which a ballot took place. Faraday’s certificate bears -twenty-nine names. The very first is that of Wollaston, and it is -followed by those of Children, Babington, Sir John Herschel, Babbage, -Phillips, Roget, and Sir James South. - -On the 5th of May, 1823, Faraday wrote to Phillips:-- - - A thousand thanks to you for your kindness--I am delighted with - the names--Mr. Brande had told me of it before I got your note - and thought it impossible to be better. I suppose you will not - be in Grosvenor Street this Evening, so I will put this in the - post. - - Our Best remembrances to Mrs. Phillips. - - Yours Ever, - M. FARADAY. - - -The certificate was read for the first time on May 1st. The absence -of the names of Davy and Brande is accounted for by the one being -President and the other Secretary. Bence Jones gives the following -account of what followed:-- - - That Sir H. Davy actively opposed Faraday’s election is no less - certain than it is sad. - - Many years ago, Faraday gave a friend the following facts, - which were written down immediately:--“Sir H. Davy told me I - must take down my certificate. I replied that I had not put - it up; that I could not take it down, as it was put up by my - proposers. He then said I must get my proposers to take it - down. I answered that I knew they would not do so. Then he - said, I as President will take it down. I replied that I was - sure Sir H. Davy would do what he thought was for the good of - the Royal Society.” - - Faraday also said that one of his proposers told him that Sir - H. Davy had walked for an hour round the courtyard of Somerset - House, arguing that Faraday ought not to be elected. This was - probably about May 30. - -Faraday also made the following notes on the circumstance of the charge -made by Wollaston’s friends:-- - - 1823. _In relation to Davy’s opposition to my election at the - Royal Society._ - - Sir H. Davy angry, May 30. - - Phillips’ report through Mr. Children, June 5. - - Mr. Warburton called first time, June 5 (evening). - - I called on Dr. Wollaston, and he not in town, June 9. - - I called on Dr. Wollaston, and saw him, June 14. - - I called at Sir H. Davy’s, and he called on me, June 17. - -On July 8 Dr. Warburton wrote that he was satisfied with Faraday’s -explanation, and added that he would tell his friends that “my -objections to you as a Fellow are and ought to be withdrawn, and that I -now wish to forward your election.” - -Bence Jones adds:-- - - On June 29, Sir H. Davy ends a note, “I am, dear Faraday, very - sincerely your well wisher and friend.” So that outwardly the - storm rapidly passed away; and when the ballot was taken, after - the certificate had been read at ten meetings, there was only - one black ball. - -[Sidenote: FELLOWSHIP AND MAGNANIMITY.] - -The election took place January 8, 1824. - -Of this unfortunate misunderstanding,[11] Davy’s biographer, Dr. -Thorpe, writes:-- - - The jealousy thus manifested by Davy is one of the most pitiful - facts in his history. It was a sign of that moral weakness - which was at the bottom of much of his unpopularity, and which - revealed itself in various ways as his physical strength - decayed.... - -Faraday allowed himself in after days no shade of resentment against -Davy; though he confessed rather sadly that after his election as -F.R.S. his relations with his former master were never the same as -before. If anyone recurred to the old scandal, he would fire with -indignation. Dumas in his “Éloge Historique” has given the following -anecdote:-- - - Faraday never forgot what he owed to Davy. Visiting him at the - family lunch, twenty years after the death of the latter, he - noticed evidently that I responded with some coolness to the - praises which the recollection of Davy’s great discoveries had - evoked from him. He made no comment. But, after the meal, he - simply took me down to the library of the Royal Institution, - and stopping before the portrait of Davy he said: “He was a - great man, wasn’t he?” Then, turning round, he added, “It was - here[12] that he spoke to me for the first time.” I bowed. We - went down to the laboratory. Faraday took out a note-book, - opened it and pointed out with his finger the words written - by Davy, at the very moment when by means of the battery he - had just decomposed potash, and had seen the first globule of - potassium ever isolated by the hand of man. Davy had traced - with a feverish hand a circle which separates them from the - rest of the page: the words, “Capital Experiment,” which - he wrote below, cannot be read without emotion by any true - chemist. I confessed myself conquered, and this time, without - hesitating longer, I joined in the admiration of my good friend. - -Dr. Thorpe in his life of Davy adds:-- - - ... To the end of his days he [Faraday] regarded Davy as his - true master, preserving to the last, in spite of his knowledge - of the moral frailties of Davy’s nature, the respect and even - reverence which is to be seen in his early lecture notes and in - his letters to his friend Abbott. - -In 1823 the Athenæum Club was started by J. Wilson Croker, Sir H. Davy, -Sir T. Lawrence, Sir F. Chantrey, and others, as a resort for literary -and scientific men. Faraday was made Club Secretary; but he found the -duties totally uncongenial, and in 1824 resigned the post to his friend -Magrath. - -Faraday was advanced in 1825 to the position of Director of the -Laboratory of the Royal Institution, Brande remaining Professor of -Chemistry. One of the first acts of the new Director was to hold -evening meetings of the members in the laboratory, when experiments -were shown and some demonstration was given. There were three or four -of these informal gatherings that year. In the next year these Friday -evening meetings were held more systematically. There were seventeen -during the season, at six of which Faraday gave discourses (see p. -100). In 1827 there were nineteen, of which he delivered three. By this -time the gatherings were held in the theatre as at present, save that -ladies were only admitted at that date, and for many years, to the -upper gallery. He also originated the Christmas lectures to juveniles, -while continuing to give regular courses of morning lectures, as his -predecessors Young and Davy had done. His activity for the Royal -Institution was incessant. - -[Sidenote: FEES FOR PROFESSIONAL WORK.] - -Down to the year 1830 Faraday continued to undertake, at professional -fees, chemical analyses and expert work in the law-courts, and thereby -added considerably to the very slender emolument of his position; -but, finding this work to make increasing demands on his time, which -he could ill spare from the absorbing pursuit of original researches, -he decided to abandon a practice which would have made him rich, and -withdrew from expert practice. The following letter to Phillips was -written only a few weeks before this determination:-- - - [_M. Faraday to Richard Phillips._] - - Royal Institution, - June 21, 1831. - - MY DEAR PHILLIPS,--I have been trying hard to get time enough - to write to you by post to-night, but without success; the - bell has rung, and I am too late. However, I am resolved to - be ready to-morrow. We have been very anxious and rather - embarrassed in our minds about your anxiety to know how things - were proceeding, and uncertain whether reference to them - would be pleasant, and that has been the cause why I have - not written to you, for I did not know what character your - connexion with Badams had. I was a little the more embarrassed - because of my acquaintance with Mr. Rickard and his family, - and, of course with his brother-in-law, Dr. Urchell, of whom I - have made numerous enquiries to know what Mr. Rickard intended - doing at Birmingham. He (expressed a) hope it would be nothing - unpleasant to you, but was not sure. Our only bit of comfort in - the matter was on hearing from Daniell about you a little; he - was here to-day, and glad to hear of you through me. But now - that I may write, let me say that Mrs. Faraday has been very - anxious with myself, and begs me earnestly to remember her to - Mrs. Phillips. We have often wished we could have had you here - for an hour or two, to break off what we supposed might be the - train of thoughts at home. - - With regard to the five guineas, do not think of it for a - moment. Whilst I supposed a mercantile concern wanted my - opinion for its own interested uses, I saw no reason why it - should not pay me; but it is altogether another matter when it - becomes _your affair_. I do not think you would have wished - _me_ to pay _you_ five guineas for anything you might have done - personally for me. “Dog don’t eat dog,” as Sir E. Home said to - me in a similar case. The affair is settled. - - I have no doubt I shall be amused and, as you speak of new - facts, instructed by your letter to Dr. Reid, as I am by all - your letters. Daniell says he thinks you are breaking a fly - upon the wheel. You know I consider you as the Prince of - Chemical critics. - - Pearsall has been working, as you know, on red manganese - solutions. He has not proved, but he makes out a strong - case for the opinion, that they owe their colour and other - properties to manganesic acid. This paper will be in the next - number of the Journal. - - With regard to the gramme, wine-pint, etc., etc., in the - manipulation I had great trouble about them, for I could find - no agreement, and at last resolved to take certain conclusions - from Capt. Kater’s paper and the Act of Parliament, and - calculate the rest. I think I took the data at page 67, - paragraph 119, as the data, but am not sure, and cannot go over - them again. - - My memory gets worse and worse daily. I will not, therefore, - say I have not received your Pharmacopœia--that of 1824 is what - I have at hand and use. I am not aware of any other. I have - sent a paper to the R. S., but not chemical. It is on sound, - etc., etc. If they print it, of course you will have a copy in - due time. - - I am, my dear Phillips, - Most faithfully and sincerely yours, - M. FARADAY. - - Is it right to ask what has become of Badams? I suppose he is, - of course, a defaulter at the R. S. - -[Sidenote: SACRIFICES FOR SCIENCE.] - -This sacrifice for science was not small. He had made £1,000 in 1830 -out of these professional occupations, and in 1831 would have made -more but for his own decision. In 1832 some Excise work that he had -retained brought him in £155 9s.; but in no subsequent year did it -bring in so much. He might easily have made £5,000 a year had he -chosen to cultivate the professional connection thus formed; and as he -continued, with little intermission, in activity till 1860, he might -have died a wealthy man. But he chose otherwise; and his first reward -came in the autumn of 1831, in the great discovery of magneto-electric -currents--the principle upon which all our modern dynamos and -transformers are based, the foundation of all the electric lighting and -electric transmission of power. From this work he went on to a research -on the identity of all the kinds of electricity, until then supposed -to be of separate sorts, and from this to electro-chemical work of the -very highest value. Of all these investigations some account will be -found in the chapters which follow. - -But the immense body of patient scientific work thus done for the love -of science was not accomplished without sacrifices of a more than -pecuniary kind. He withdrew more and more from society, declined to -dine in company, ceased to give dinners, withdrew from all social and -philanthropic organisations; even withdrew from taking any part in the -management of any of the learned societies. The British Association for -the Advancement of Science was started in 1831. Faraday took no part -in that movement, and did not attend the inaugural meeting at York. -The next year, however, he attended the second meeting of that body at -Oxford. Here he “had the pleasure”--it is his own phrase--of making -an experiment on the great magnet in the University museum, drawing a -spark by induction in a coil of wire. This was a coil 220 feet long, -wound on a hollow cylinder of pasteboard, which had been used in the -classical experiments of the preceding year. He also showed that the -induced currents could heat a thin wire connected to the terminals -of this coil. These experiments, which were made in conjunction with -Mr. (afterwards Sir William Snow) Harris, Professor Daniell, and -Mr. Duncan, seem to have excited great attention at the time. The -theologians of Oxford appear to have been mightily distressed both by -the success of the spark experiment and by the welcome shown by the -University to the representatives of science. The following passage -from Pusey’s life[13] reveals the rampant clericalism which then and -for a score of years sought to put back the clock of civilisation. - - During the Long Vacation of 1832 Pusey had plenty of work on - hand. The British Association had held its first meeting in - Oxford during the month of June, and on the 21st the honorary - degree of D.C.L. was bestowed on four of its distinguished - members: Brewster, Faraday, Brown, and Dalton. Keble, who was - now Professor of Poetry, was angry at the “temper and tone of - the Oxford doctors”; they had “truckled sadly to the spirit of - the times” in receiving “the hodge-podge of philosophers” as - they did. Dr. L. Carpenter had assured Dr. Macbride that “the - University had prolonged her existence for a hundred years by - the kind reception he and his fellows had received.” - -[Sidenote: THE HODGE-PODGE OF PHILOSOPHERS.] - -It is not without significance, perhaps, that all the four men thus -contemptuously labelled by Keble as the “hodge-podge of philosophers” -were Dissenters. Brewster and Brown (the great botanist and discoverer -of the “Brownian” motion of particles) belonged to the Presbyterian -Church of Scotland, Dalton was a Member of the Society of Friends, and -Faraday a Sandemanian. Newman appears to have been equally discomposed -by the circumstance, for he got his friend Mr. Rose to write an -article--a long and weary diatribe--against the British Association, -which he inserted in the _British Critic_ for 1839. Its slanders, -assumptions, suppressions, and suggestions are in a very unworthy -temper. - -Faraday’s devotion to the Royal Institution and its operations was -marvellous. He had already abandoned outside professional work. From -1838 he refused to see any callers except three times a week. His -extreme desire was to give himself uninterruptedly to research. His -friend A. de la Rive says:-- - - Every morning Faraday went into his laboratory as the man of - business goes to his office, and then tried by experiment the - truth of the ideas which he had conceived overnight, as ready - to give them up if experiment said _no_ as to follow out the - consequences with rigorous logic if experiment answered _yes_. - -He had in 1827 declined the appointment of Professor of Chemistry in -the University (afterwards called University College) of London, giving -as his reason the interests of the Royal Institution. He wrote:-- - - I think it a matter of duty and gratitude on my part to do - what I can for the good of the Royal Institution in the - present attempt to establish it firmly. The Institution has - been a source of knowledge and pleasure to me for the last - fourteen years; and though it does not pay me in salary what - I _now_ strive to do for it, yet I possess the kind feelings - and goodwill of its authorities and members, and all the - privileges it can grant or I require; and, moreover, I remember - the protection it has afforded me during the past years of - my scientific life. These circumstances, with the thorough - conviction that it is a useful and valuable establishment, and - the strong hopes that exertions will be followed with success, - have decided me in giving at least two years more to it, in the - belief that after that time it will proceed well, into whatever - hands it may pass. - -In 1829, however, he was asked to become lecturer on chemistry at the -Royal Academy at Woolwich. As this involved only twenty lectures a year -he agreed, the salary being fixed at £200 a year. These lectures were -continued until 1849. - -[Sidenote: TRINITY HOUSE APPOINTMENT.] - -In 1836 the whole course of his scientific work was changed by his -appointment as scientific adviser to Trinity House, the body which has -official charge of the lighthouse service in Great Britain. To the -Deputy-master he wrote:-- - - I consider your letter to me as a great compliment, and should - view the appointment at the Trinity House, which you propose, - in the same light; but I may not accept even honours without - due consideration. - - In the first place, my time is of great value to me; and if - the appointment you speak of involved anything like periodical - routine attendances, I do not think I could accept it. But - if it meant that in consultation, in the examination of - proposed plans and experiments, in trials, etc., made as - my convenience would allow, and with an honest sense of a - duty to be performed, then I think it would consist with my - present engagements. You have left the title and the sum in - pencil. These I look at mainly as regards the character of the - appointment; you will believe me to be sincere in this when you - remember my indifference to your proposition as a matter of - interest, though _not as a matter of kindness_. - - In consequence of the goodwill and confidence of all around me, - I can at any moment convert my time into money, but I do not - require more of the latter than is sufficient for necessary - purposes. The sum, therefore, of £200 is quite enough in - itself, but not if it is to be the indicator of the character - of the appointment; but I think you do not view it so, and - that you and I understand each other in that respect; and - your letter confirms me in that opinion. The position which I - presume you would wish me to hold is analogous to that of a - standing counsel. - - As to the title, it might be what you pleased almost. Chemical - adviser is too narrow, for you would find me venturing into - parts of the philosophy of light not chemical. Scientific - adviser you may think too broad (or in me too presumptuous); - and so it would be, if by it was understood all science. - -He held the post of scientific adviser for nearly thirty years. The -records of his work are to be found in nineteen large portfolios full -of manuscripts, all indexed with that minute and scrupulous attention -to order and method which characterised all his work. - -He also held nominally the post of scientific adviser to the Admiralty, -at a salary of £200 a year. But this salary he never drew. Once the -officials of the Admiralty requested his opinion upon a printed -advertising pamphlet of somebody’s patent disinfecting powder and -anti-miasma lamp. Faraday returned it, with a quietly indignant protest -that it was not such a document as he could be expected to give an -opinion upon. - -Faraday’s hope, expressed in 1827, that in two years the Royal -Institution might be restored to a financially sound position, was -not realised. He worked with the most scrupulous economy, noting down -every detail of expenditure even in farthings. “We were living on -the parings of our own skin,” he once told the managers. In 1832 the -financial question became acute. At the end of that year a committee of -investigation reported as follows:-- - - The Committee are certainly of opinion that no reduction can be - made in Mr. Faraday’s salary--£100 per annum, house, coals, and - candles; and beg to express their regret that the circumstances - of the Institution are not such as to justify their proposing - such an increase of it as the variety of duties which Mr. - Faraday has to perform, and the zeal and ability with which he - performs them, appear to merit. - -[Sidenote: A HUNDRED A YEAR, AND TWO ROOMS.] - -A hundred a year, the use of two rooms, and coals! Such was the stipend -of the man who had just before been made D.C.L. of Oxford, and had -received from the Royal Society the highest award it can bestow--the -Copley Medal! True, he made £200 by the Woolwich lectures; but he had a -wife to maintain, his aged mother was entirely dependent upon him, and -there were many calls upon his private exercise of charity. - -About the year 1835 it was the intention of Sir Robert Peel to -confer upon him a pension from the Civil List, but he went out of -office before this could be arranged, and Lord Melbourne became -Prime Minister. Sir James South had in March written to Lord Ashley, -afterwards the well-known Earl of Shaftesbury, asking him to place a -little historiette of Faraday in Sir Robert Peel’s hands. The said -historiette[14] contained an account of Faraday’s early career and -a description of the electrical machine which he had constructed as -a lad. “Now that his pecuniary circumstances,” it went on, “were -improved, he sent his younger sister to boarding-school, but to enable -him to defray the expense, to deprive himself of dinner every other day -was absolutely indispensable.” Peel expressed to Ashley lively regret -at not having received the historiette earlier when he was still in -office. To Ashley, later, he wrote the following hitherto unpublished -letter:-- - - Drayton Manor, - May 3, 1835. - - MY DEAR ASHLEY,--You do me but justice in entertaining the - belief that had I remained in office one of my earliest - recommendations to his Majesty would have been to grant a - pension to Mr. Faraday, on the same principles precisely upon - which one was granted to Mr. Airy. If there had been the means, - I would have made the offer before I left office. - - I was quite aware of Mr. Faraday’s high eminence as a man of - science, and the valuable practical service he has rendered - to the public in that capacity; but I was to blame in not - having ascertained whether his pecuniary circumstances made an - addition to his income an object to him. - - I am sure no man living has a better claim to such a - consideration from the State than he has, and I trust the - principle I acted on with regard to the award of civil - pensions will not only remove away impediments of delicacy - and independent feeling from the acceptance of them, but will - add a higher value to the grant of a pension as an honourable - distinction than any that it could derive from its pecuniary - amount. - - Ever, my dear Ashley, - Most faithfully yours, - ROBERT PEEL. - - -[Sidenote: LORD MELBOURNE’S PARTICIPLE.] - -Sir James South still endeavoured to bring about the grant thus -deferred, and wrote to the Hon. Caroline Fox, asking her to put the -historiette of Faraday in the hands of Lord Holland, for him to lay -before Melbourne. Faraday at first demurred to Sir James South’s -action, but on the advice of his father-in-law, Barnard, withdrew his -demurrer. Later in the year he was asked to wait on Lord Melbourne at -the Treasury. He has left a diary of the events of the day, October -26th. According to these notes it appears that Faraday first had -a long talk with Melbourne’s secretary, Mr. Young, about his first -demurring on religious grounds to accept the pension, about his -objection to savings’ banks, and the laying-up of wealth. Later in -the day he had a short interview with the First Lord of the Treasury, -when Lord Melbourne, utterly mistaking the nature of the man before -him, inveighed roundly upon the whole system of giving pensions to -scientific and literary persons, which he described as a piece of -humbug. He prefixed the word “humbug” with a participle which Faraday’s -notes describe as “theological.” Faraday, with an instant flash of -indignation, bowed and withdrew. The same evening he left his card and -the following note at the Treasury:-- - - _To the Right Hon. Lord Viscount Melbourne, First Lord of the - Treasury._ - - October 26. - - MY LORD,--The conversation with which your Lordship honoured - me this afternoon, including, as it did, your Lordship’s - opinion of the general character of the pensions given of late - to scientific persons, induces me respectfully to decline the - favour which I believe your Lordship intends for me; for I - feel that I could not, with satisfaction to myself, accept at - your Lordship’s hands that which, though it has the form of - approbation, is of the character which your Lordship so pithily - applied to it. - -Faraday’s diary says:-- - - Did not like it much, and, on the whole, regret that friends - should have placed me in the situation in which I found myself. - Lord Melbourne said that “he thought there had been a great - deal of humbug in the whole affair. He did not mean my affair, - of course, but that of the pensions altogether.”... I begged - him to understand that I had known nothing of the matter until - far advanced, and, though grateful to those friends who had - urged it forward, wished him to feel at perfect liberty in the - affair as far as I was concerned.... In the evening I wrote and - left a letter. I left it myself at ten o’clock at night, being - anxious that Lord Melbourne should have it before anything - further was done in the affair. - -[Sidenote: MICHAEL’S PENSION.] - -However, the matter did not end here. Faraday’s friends were indignant. -A caustic, and probably exaggerated, account--for which Faraday -disclaimed all responsibility--of the interview appeared in _Fraser’s -Magazine_, and was copied into _The Times_ of November 28th, with the -result that, had it not been for the personal intervention of the King, -the pension might have been refused. The storm, however, passed away, -and the pension of £300 per annum was granted on December 24th. Years -afterwards, writing to Mr. B. Bell, Faraday said, “Lord Melbourne -behaved very handsomely in the matter.” - -In _Fraser’s Magazine_ for February, 1836 (vol. xiii., p. 224), is -a portrait of Faraday by Maclise, accompanied by a very amusing -biographical notice by Dr. Maginn. The picture represents Faraday -lecturing, and surrounded by his apparatus. The article begins thus:-- - - Here you have him in his glory--not that his position was - _inglorious_ when he stood before Melbourne, then decorated - with a blue velvet travelling cap, and lounging with one - leg over the chair of Canning!--and distinctly gave that - illustrious despiser of “humbug” to understand that he had - mistaken his lad. No! but here you have him as he first - flashed upon the intelligence of mankind the condensation of - the gases, or the identity of the five electricities. - -After a lively summary of his career, and the jocular suggestion that, -as the successor of Sir Humphry Davy, Far-a-day must be near-a-knight -the article continues:-- - - The future Baronet is a very good little fellow ... playing a - fair fork over a leg of mutton, and devoid of any reluctance - to partake an old friend’s third bottle. We know of few things - more agreeable than a cigar and a bowl of punch (which he mixes - admirably) in the society of the unpretending ex-bookbinder.... - - Well, although Young got Broderip to write a sort of defence of - his master, and “Justice B----”--_mirabile dictu!_--got Hook - to print it in the _John Bull_, the current of public feeling - could not be stopped: REGINA spoke out--WILLIAM REX, as in duty - bound, followed--Melbourne apologised--and “Michael’s pension, - Michael’s pension” is all right. - -In one of his note-books of this period is found the following entry:-- - - 15 January, 1834. - - Within the last week have observed twice that a slight - obscurity of the sight of my left eye has happened. It occurred - on reading the letters of a book held about fourteen inches - from the eye, being obscured as by a fog over a space about - half an inch in diameter. This space was a little to the right - and below the axes of the eye. Looking for the effect now and - other times, I cannot perceive it. I note this down that I may - hereafter trace the progress of the effect if it increases or - becomes more common. - -Happily, the trouble did not recur; but the entry is characteristic -of the habits of accuracy of the man. Loss of memory, unfortunately, -early set in. There is actually a hint of this in the first of -his letters to Abbott (p. 7), and references to the trouble and to -dizziness in the head recur perpetually in his correspondence. Whenever -these brain-troubles threatened, he was compelled to drop all work -and seek rest and change of scene. He often ran down to Brighton, -which he thought, however, a poor place. He constructed for himself a -velocipede[15] on which to take exercise. Two or three times he went to -Switzerland for a longer holiday, usually accompanied by his wife and -her brother, George Barnard. - -“Physically,” says Tyndall, “Faraday was below the middle size, well -set, active, and with extraordinary animation of countenance. His head -from forehead to back was so long that he had usually to bespeak his -hats.” In youth his hair was brown, curling naturally; later in life it -approached to white, and he always parted it down the middle. His voice -was pleasant, his laugh was hearty, his manners when with young people, -or when excited by success in the laboratory, were gay to boyishness. -Indeed, until the end of the active period of his life he never lost -the capacity for boyish delight, or for unbending in fun after the -stress of severe labour. - - - - -CHAPTER III. - -SCIENTIFIC RESEARCHES: FIRST PERIOD. - - -From first to last the original scientific researches of Faraday extend -over a period of forty-four years, beginning with an analysis of -caustic lime, published in the _Quarterly Journal of Science_ in 1816, -and ending with his last unfinished researches of 1860 to 1862, on -the possible existence of new relations between magnetism and gravity -and between magnetism and light. The mere list of their titles fills -several pages in the catalogue of scientific papers published by the -Royal Society. - -For convenience of description, these forty-four years may be divided -into three periods: the first lasting from 1816 to 1830, a period of -miscellaneous and in some respects preliminary activity; the second -from 1831 to the end of 1839, the period of the classical experimental -researches in electricity down to the time when they were temporarily -suspended by the serious state of his health; the third from 1844, when -he was able to resume work, down to 1860, a period which includes the -completion of the experimental researches on electricity, the discovery -of the relations between light and magnetism, and that of diamagnetism. - -[Sidenote: RESEARCHES BEGINNING.] - -Faraday’s first research was an analysis for Sir Humphry Davy of a -specimen of caustic lime which had been sent to him by the Duchess -of Montrose from Tuscany. The _Quarterly Journal of Science_, in -which it appeared, was a precursor of the _Proceedings of the Royal -Institution_, and was indeed edited by Professor W. F. Brande. Faraday -frequently wrote for it during these years, and took editorial -charge of it on more than one occasion during Brande’s holidays. The -paper on caustic lime was reprinted by Faraday in the volume of his -“Experimental Researches on Chemistry and Physics,” prefaced by the -following note:-- - - I reprint this paper at full length; it was the beginning - of my communications to the public, and in its results very - important to me. Sir Humphry Davy gave me the analysis to - make as a first attempt in chemistry, at a time when my fear - was greater than my confidence, and both far greater than - my knowledge; at a time also when I had no thought of ever - writing an original paper on science. The addition of his own - comments, and the publication of the paper, encouraged me to - go on making, from time to time, other slight communications, - some of which appear in this volume. Their transference from - the _Quarterly_ into other journals increased my boldness, - and now that forty years have elapsed, and I can look back on - what successive communications have led to, I still hope, much - as their character has changed, that I have not either now or - forty years ago been too bold. - -For the next two or three years Faraday was very closely occupied in -the duties of assisting Sir Humphry Davy in his researches, and in -helping to prepare the lectures for both Davy and Brande. Yet he -found time still to work on his own account. In 1817 he had six papers -and notes in the _Quarterly Journal of Science_, including one on the -escape of gases through capillary tubes, and others on wire-gauze -safety lamps and Davy’s experiments on flame. In 1818 he had eleven -papers in the _Journal_; the most important being on the production of -sound in tubes by flames, while another was on the combustion of the -diamond. In 1819 he had nineteen papers in the _Quarterly Journal_, -chiefly of a chemical nature. These related to boracic acid, the -composition of steels, the separation of manganese from iron, and on -the supposed new metal, “Sirium” or “Vestium,” which he showed to be -only a mixture of iron and sulphur with nickel, cobalt, and other -metals. - -[Sidenote: OERSTED’S DISCOVERY.] - -The year 1820 was marked in the annals of science by the discovery, -by Oersted of Copenhagen, of the prime fact of electromagnetism, the -deflexion which is produced upon a magnetic needle by an electric -current that passes either under or over the needle. Often had it been -suspected that there must be some connection between the phenomena -of electricity and those of magnetism. The similarities between the -attractions and repulsions caused by electrified bodies, and those -due to the magnet when acting on iron, had constantly suggested the -possibility that there was some real connection. But, as had been -pointed out centuries before by St. Augustine, while the rubbed -amber will attract any substance if only small or light enough, -being indifferent to its material, the magnet will only attract iron -or compounds of iron, and is totally inoperative[16] on all other -substances. Again, while it had been noticed that in houses which had -been struck by lightning knives, needles, and other steel objects near -the path of the electric flash had become magnetised, no one had been -able, by using the most powerful electric machines, to repeat with -certainty the magnetisation of needles. In vain they had tried to -magnetise knives and wires by sending sparks through them. Sometimes -they showed a trace of magnetism, sometimes none. And in the cases -where some slight magnetisation resulted, the polarity could not be -depended upon. Van Swinden had written a whole treatise in two volumes -on the analogies between electricity and magnetism, but left the real -relation between the two more obscure than ever. After the invention, -in 1800, of the voltaic pile, which for the first time provided a -means of generating a steady flow or current of electricity, several -experimenters, including Oersted himself, had again essayed to discover -the long-suspected connection, but without success. Oersted was -notoriously a poor experimenter, though a man of great philosophical -genius. Having in 1820 a more powerful voltaic battery in operation -than previously, he repeated[17] the operation of bringing near to the -compass needle the copper wire that conveyed the current; and, laying -it parallel to the needle’s direction, and over or under it, found that -the needle tended to turn into a direction at right angles to the line -of the current, the sense of the deviation depending upon the direction -of flow of the current, and also on the position of the wire as to -whether it were above or below the needle. A current flowing from south -to north over the needle caused the north-pointing end of the needle to -be deflected westwards. If the wire were vertical, so that the current -flowed downwards, and a compass needle was brought near the wire on the -south side, therefore tending under the earth’s directive influence to -point northwards toward the wire, it was observed that the effect of -the current flowing in the wire was to cause the north-pointing end of -the needle to turn westwards. Or, reversing the flow of current, the -effect on the needle was reversed; it now tended eastwards. All these -things Oersted summed up in the phrase that “the electric conflict acts -in a revolving manner” around the wire.[18] In modern phraseology the -whole of the actions are explained if one can conceive that the effect -of the electric flow in the wire is to tend to make the north pole of -a magnet revolve in one sense around the wire, whilst it also tends -to make the south pole of the magnet revolve around the wire in the -other sense. The nett result in most cases is that the magnetic needle -tends to set itself square across the line of the current. Oersted -himself was not too clear in his explanations, and seems, in his later -papers, to have lost sight of the circular motion amidst repulsions and -attractions. - -This discovery, which showed what was the geometrical relation between -the magnet and the current, also showed why the earlier attempts had -failed. It was requisite that the electricity should be in a state -of steady flow; neither at rest as in the experiments with electric -charges, nor yet in capricious or oscillatory rush as in those with -spark-discharges. Faraday, adverting a quarter of a century later to -Oersted’s discovery, said: “It burst open the gates of a domain in -science, dark till then, and filled it with a flood of light.” - -The very day that Oersted’s memoir was published in England, Davy -brought a copy down into the laboratory of the Royal Institution, and -he and Faraday at once set to work to repeat the experiments and verify -the facts. - -It is a matter of history how, on the publication of Oersted’s -discovery, Ampère leaped forward to generalise on electromagnetic -actions, and discovered the mutual actions that may exist between two -currents, or rather between two conducting wires that carry currents. -They are found to experience mutual mechanical forces urging them into -parallel proximity. Biot and Laplace added to these investigations, -as also did Arago. Davy discovered that the naked copper wire, while -carrying a current, could attract iron filings to itself--not end-ways -in adherent tufts, as the pole of a magnet does, but laterally, each -filing or chainlet of filings tending to set itself tangentially at -right angles to the axis of the wire. - -[Sidenote: A PARADOXICAL PHENOMENON.] - -This curious right-angled relation between electric flow and magnetic -force came as a complete paradox or puzzle to the scientific world. -It had taken centuries to throw off the strange unmechanical ideas of -force which had dominated the older astronomy. The epicyclic motions -of the planets postulated by the Ptolemaic system were in no way to be -accounted for upon mechanical principles. Kepler’s laws of planetary -motion were merely empirical, embodying the results of observation, -until Newton’s discovery of the laws of circular motion and of the -principle of universal gravitation placed the planetary theory on -a rational basis. Newton’s laws required that forces should act in -straight lines, and that to every action there should be an equal and -opposite reaction. If A attracted B, then B attracted A with an equal -force, and the mutual force must be in the line drawn from A to B. The -discovery by Oersted that the magnet pole was urged by the electric -wire in a direction _transverse_ to the line joining them, appeared at -first sight to contravene the ideas of force so thoroughly established -by Newton. How could this transversality be explained? Some sought to -explain the effect by considering the conducting wire to operate as if -made up of a number of short magnets set transversely across the wire, -all their north poles being set towards the right, and all their south -poles towards the left. Ampère took the alternative view that the -magnet might be regarded as equivalent to a number of electric currents -circulating transversely around the core as an axis. In neither case -was the explanation complete. - -[Sidenote: TWO YEARS WASTED.] - -Faraday’s scientific activities in the year 1820 were very marked. New -researches on steel had been going on for some months. It had been -hoped that by alloying iron with some other metals, such as silver, -platinum, or nickel, a non-rusting alloy might be found. This idea -took its rise from the erroneous notion that meteoric iron, which -is richly alloyed with nickel, does not rust. Faraday found nickel -steel to be more readily oxidised, not less, than ordinary steel. The -platinum steel was also a failure. Silver steel was of more interest, -though it was found impossible to incorporate in the alloy more than -a small percentage of silver. Nevertheless, silver steel was used -for some time by a Sheffield firm for manufacture of fenders. The -alloys of iron with platinum, iridium, and rhodium were also of no -great use. But the research demonstrated the surprising effects which -minute quantities of other metals may have upon the quality of steel. -Occasionally in later life Faraday would present one of his friends -with a razor made from his own special steel. A paper on the use of -alloys of steel in surgical instrument making was published in the -_Quarterly Journal_ in collaboration with Mr. Stodart. Faraday also -read his first paper before the Royal Society on two new compounds -of chlorine and carbon, and on a new compound of iodine, carbon, -and hydrogen. He also succeeded in making artificial plumbago from -charcoal. In writing to his friend Professor G. de la Rive, he gives -a long and chatty abstract of his researches on the alloys of steel. -They appear to have originated in some analyses of wootz or Indian -steel, a material which, when etched with acid, shows a beautifully -damascened or reticulated surface. This effect Faraday never found with -pure steel, but imitated it successfully with a steel alloyed with “the -metal of alumine,” an element which down to that time had not been -isolated. He then describes the rhodium, silver, and nickel steels, and -mentions incidentally how he has been surprised to discover that he -can volatilise silver, and that he cannot reduce the metal titanium. -He is doubtful whether this metal “ever has been reduced at all in the -pure state.” [It can now be readily reduced either in the electric arc -or by the use of metallic aluminium.] He winds up the letter with the -words: “Pray pity us that, after two years’ experiments, we have got no -further; but I am sure, if you knew the labour of the experiments, you -would applaud us for our perseverance at least.” - -In 1821, the year of his marriage, came the first of the important -scientific discoveries which brought him international fame. This -was the discovery of the electromagnetic rotations. It appears that -Oersted’s brilliant flash of insight that the “electric conflict acts -in a revolving manner” upon the pole of the neighbouring compass needle -had been lost sight of in the discussions which followed, and to -which allusion has been made above. All the world was thinking about -attractions and repulsions. Two men, however, seem to have gone a -little further in their ideas. Dr. Wollaston had suggested that there -ought to be a tendency, when a magnet pole was presented towards a -straight conducting wire carrying a current, for that conducting wire -to revolve around its own axis. This effect--though in recent years -it has been observed by Mr. George Gore--he unsuccessfully tried to -observe by experiments. He came in April, 1821, to the laboratory -of the Royal Institution to make an experiment, but without result. -Faraday, at the request of his friend Phillips, who was editor of the -_Annals of Philosophy_, wrote for that magazine in July, August, and -September a historical sketch of electromagnetism down to date. This -was one of the very few of Faraday’s writings that was anonymous. It -was simply signed “M.” This is in vol. iii. p. 107. On p. 117 the -editor says: “To the historical sketch of electromagnetism with which I -have been favoured by my anonymous correspondent, I shall add a sketch -of the discoveries that have been made by Mr. Faraday of the Royal -Institution.” In the course of this work Faraday repeated for his own -satisfaction almost all the experiments that he described. This led him -to discover that a wire, included in the circuit, but mounted so as to -hang with its lower end in a pool of quicksilver, could rotate around -the pole of a magnet; and conversely that if the wire were fixed and -the pole of the magnet free to move, the latter would rotate around the -former. “I did not realise,” he wrote, “Dr. Wollaston’s expectation -of the rotation of the electromagnetic wire around its axis.” As was -so often his custom, he had no sooner finished the research for -publication than he dashed off a brief summary of it in a letter to one -of his friends. On this occasion it was Professor G. de la Rive, of -Geneva, who was the recipient of his confidences. On September 12 he -wrote:-- - -[Sidenote: LETTER TO DE LA RIVE.] - - I am much flattered and encouraged to go on by your good - opinion of what little things I have been able to do in - science, and especially as regards the chlorides of carbon. - - * * * * * - - You partly reproach us here with not sufficiently esteeming - Ampère’s experiments on electromagnetism. Allow me to extenuate - your opinion a little on this point. With regard to the - experiments, I hope and trust that due weight is allowed to - them; but these you know are few, and theory makes up the great - part of what M. Ampère has published, and theory in a great - many points unsupported by experiments when they ought to have - been adduced. At the same time, M. Ampère’s experiments are - excellent, and his theory ingenious; and, for myself, I had - thought very little about it before your letter came, simply - because, being naturally sceptical on philosophical theories, I - thought there was a great want of experimental evidence. Since - then, however, I have engaged on the subject, and have a paper - in our “Institution Journal,” which will appear in a week or - two, and that will, as it contains experiment, be immediately - applied by M. Ampère in support of his theory, much more - decidedly than it is by myself. I intend to enclose a copy of - it to you with the other, and only want the means of sending it. - - I find all the usual attractions and repulsions of the magnetic - needle by the conjunctive wire are deceptions, the motions - being not attractions or repulsions, nor the result of any - attractive or repulsive forces, but the result of a force in - the wire, which instead of bringing the pole of the needle - nearer to, or further from the wire, endeavours to make it - move round it in a never ending circle and motion whilst the - battery remains in action. I have succeeded not only in showing - the existence of this motion theoretically, but experimentally, - and have been able to make the wire revolve round a magnetic - pole, or a magnetic pole round the wire, at pleasure. The law - of revolution, and to which all the other motions of the needle - and wire are reducible, is simple and beautiful. - - Conceive a portion of connecting wire north and south, the - north end being attached to the positive pole of a battery, the - south to the negative. A north magnetic pole would then pass - round it continually in the apparent direction of the sun, from - east to west above, from west to east below. - - Reverse the connections with the battery, and the motion of the - pole is reversed; or if the south pole be made to revolve, the - motions will be in the opposite directions, as with the north - pole. - - If the wire be made to revolve round the pole, the motions are - according to those mentioned. In the apparatus I used there - were but two plates, and the directions of the motions were of - course[19] the reverse of those with a battery of several pairs - of plates, and which are given above. Now I have been able, - experimentally, to trace this motion into its various forms as - exhibited by Ampère’s, Nelice’s, &c., and in all cases to show - that the attractions and repulsions are only appearances due - to this circulation of the pole, to show that dissimilar poles - repel as well as attract, and that similar poles attract as - well as repel, and to make, I think, the analogy between the - helix and common bar magnet far stronger than before. But yet I - am by no means decided that there are currents of electricity - in the common magnet. - - I have no doubt that electricity puts the circles of the - helix into the same state as those circles are in, that may - be conceived in the bar magnet, but I am not certain that - this state is directly dependant on the electricity, or that - it cannot be produced by other agencies; and therefore, until - the presence of electrical currents be proved in the magnet by - other than magnetical effects, I shall remain in doubt about - Ampère’s theory. - - * * * * * - - Wishing you all health and happiness, and waiting for news from - you, - - I am, my dear Sir, your very obliged and grateful - - M. FARADAY. - - -The reference at the beginning of this letter to the chlorides of -carbon has to do with his discovery communicated to the Royal Society. -Later in the year, a joint paper on another compound of carbon and -chlorine, by himself and his friend Richard Phillips, was sent in. Both -were printed together in the _Philosophical Transactions_ of 1821. - -[Sidenote: LEAVES FROM THE NOTE-BOOK.] - -The following is an extract from Faraday’s laboratory book relating to -the discovery. The account is incomplete, a leaf having been torn out:-- - - 1821, Sept. 3. - - The effort of the wire is always to pass off at a right angle - from the pole, indeed to go in a circle round it, so when - either pole was brought up to the wire perpendicular to it and - to the radius of the circle it described, there was neither - attraction nor repulsion, but the moment the pole varied in the - slightest manner either in or out, the wire moved one way or - the other. - - The poles of the magnet act on the bent wire in all positions - and not in the direction _only_ of any axis of the magnet, so - that the current can hardly be cylindrical or arranged round - the axis of a cylinder? - - From the motion above a north magnet pole in the centre of one - of the circles should make the wire continually turn round. - Arranged a magnet needle in a glass tube with mercury about it, - and by a cork, water, &c., supported a connecting wire so that - the upper end should go into the silver cup and its mercury, - and the lower move in a channel of mercury round the pole of - the needle. The battery arranged with the wire as before. In - this way got the revolution of the wire round the pole of the - magnet. The direction was as follow, looking from above down:-- - - [Illustration: FIG. 2. (FACSIMILE OF ORIGINAL SKETCH.)] - - Very satisfactory, but make more sensible apparatus. - - Tuesday, Sept. 4. - - Apparatus for revolution of wire and magnet. A deep basin with - bit of wax at bottom and then filled with mercury. A magnet - stuck upright in wax so that pole just above the surface of - mercury. Then piece of wire floated by cork at lower end - dipping into merc^y and above into silver cup as before:-- - - [Illustration: FIG. 3. (FACSIMILE OF ORIGINAL SKETCH.)] - -The research on the electromagnetic rotations, which was published in -the _Quarterly Journal of Science_ for October, 1821 (and reprinted in -the second volume of the “Experimental Researches in Electricity”), was -the occasion of a very serious misunderstanding with Dr. Wollaston and -his friends, which at one time threatened to cause Faraday’s exclusion -from the Royal Society. Faraday’s prompt and frank action in appealing -to Dr. Wollaston saved him in a very unpleasant crisis; and the latter -came three or four times to the laboratory to witness the experiments. -On Christmas Day of the same year, Faraday succeeded in making a wire -through which an electric current is passing move under the influence -of the earth’s magnetism alone. His brother-in-law, George Barnard, who -was in the laboratory at the time, wrote:--“All at once he exclaimed, -‘Do you see, do you see, do you see, George?’ as the wire began to -revolve. One end I recollect was in the cup of quicksilver, the other -attached above to the centre. I shall never forget the enthusiasm -expressed in his face and the sparkling in his eyes!” - -[Sidenote: SCENES IN THE LABORATORY.] - -In 1822 little was added to Faraday’s scientific work. He had a -joint paper with Stodart on steel before the Royal Society, and -in the _Quarterly Journal_ two short chemical papers and four on -electromagnetical motions and magnetism. He had long kept a commonplace -book in which he entered notes and queries as well as extracts from -books and journals; but this year he began a fresh manuscript volume, -into which he transferred many of the queries and suggestions of -his own originating. This volume he called “Chemical Notes, Hints, -Suggestions, and Objects of Pursuit.” It contains many of the germs of -his own future discoveries, as the following examples show:-- - - Convert magnetism into electricity. - - Do pith balls diverge by disturbance of electricities in - consequence of induction or not? - - General effects of compression, either in condensing gases, - or producing solutions, or even giving combinations at low - temperatures. - - Light through gold leaf on to zine or most oxidable metals, - these being poles--or on magnetic bars. - - Transparency of metals. Sun’s light through gold leaf. Two gold - leaves made poles--light passed through one to the other. - -Whenever any query found an answer, he drew his pen through it and -added the date. In front of the book--probably at some later time--he -wrote these words:-- - - I already owe much to these notes, and think such a collection - worth the making by every scientific man. I am sure none would - think the trouble lost after a year’s experience. - -A striking example had already occurred of similar suggestive notes in -the optical queries of Sir Isaac Newton. - -In another manuscript notebook occur the following entries under date -of September 10, 1821:-- - - 2 similar poles though they repell at most distances attract at - very small distances and adhere. Query why.... - - Could not magnetise a plate of steel so as to resemble flat - spiral. Either the magnetism would be very weak and irregular - or there would be none at all. - -These are interesting as showing how Faraday was educating himself -by continual experiment. The explanation of each of these paradoxes -has long passed into the commonplace of physics; but they would still -puzzle many who have learned their science bookishly at second-hand. - -It will be noted that amongst the entries cited above there are two of -absolutely capital importance, one foreshadowing the great discovery -of magneto-electric induction, the other indicating how the existence -of electro-optical relations was shaping itself as a possibility in -Faraday’s mind. An entry in his laboratory book of September 10 is of -great interest:-- - - Polarised a ray of lamp-light by reflection, and endeavoured to - ascertain whether any depolarising action [is] exerted on it by - water placed between the poles of a voltaic battery in a glass - cistern; one Wollaston’s trough used; the fluids decomposed - were pure water, weak solution of sulphate of soda, and strong - sulphuric acid: none of them had any effect on the polarised - light, either when out of or in the voltaic circuit, so that - no particular arrangement of particles could be ascertained in - this way. - -[Sidenote: AN UNSUCCESSFUL EXPERIMENT.] - -It may be added that no such optical effect of electrolytic conduction -as that here looked for has yet been discovered. The experiment, -unsuccessful at that day, remains still an unsuccessful one. A singular -interest attaches to it, however, and it was repeated several times by -Faraday in subsequent years, in hope of some results. - -In 1823 Faraday read two papers to the Royal Society, one on Liquid -Chlorine, the other on the Condensation of several Gases into Liquids. -No sooner was the work completed than he dashed off a letter to De la -Rive to tell him what he had accomplished. Under date March 24, 1823, -he writes:-- - - I have been at work lately, and obtained results which I - hope you will approve of. I have been interrupted twice in - the course of experiments by explosions, both in the course - of eight days--one burnt my eyes, the other cut them; but - fortunately escaped with slight injury only in both cases, and - am now nearly well. During the winter I took the opportunity - of examining the hydrate of chlorine, and analysing it; the - results, which are not very important, will appear in the - next number of the _Quarterly Journal_, over which I have no - influence. Sir H. Davy, on seeing my paper, suggested to me to - work with it under pressure, and see what would happen by heat, - &c. Accordingly I enclosed it in a glass tube hermetically - sealed, heated it, obtained a change in the substance, and - a separation into two different fluids; and upon further - examination I found that the chlorine and water had separated - from each other, and the chlorine gas, not being able to - escape, had condensed into the liquid form. To prove that it - contained no water, I dried some chlorine gas, introduced it - into a long tube, condensed it, and then cooled the tube, and - again obtained fluid chlorine. Hence what is called chlorine - gas is the vapour of a fluid.... - - * * * * * - - I expect to be able to reduce many other gases to the liquid - form, and promise myself the pleasure of writing you about - them. I hope you will honour me with a letter soon. - - I am, dear Sir, very faithfully, your obedient servant, - - M. FARADAY. - - -[Sidenote: CHLORINE LIQUEFIED.] - -The work of liquefying the gases had been taken up by Faraday -during his hours of liberty from other duties. It was probably his -characteristic dislike to “doubtful knowledge” which prompted him to -re-examine a substance which had at one time been regarded as chlorine -in a solid state, but which Davy in 1810 had demonstrated to be a -hydrate of that element. The first work was, as narrated above, to make -a new analysis of the supposed substance. This analysis, duly written -out, was submitted to Sir Humphry, who, without stating precisely what -results he anticipated might follow, suggested heating the hydrate -under pressure in a hermetically sealed glass tube. This Faraday did. -When so heated, the tube filled with a yellow atmosphere, and on -cooling was found to contain two liquids, one limpid and colourless -like water, the other of an oily appearance. Concerning this research -a curious story is told in the life of Davy. Dr. Paris, Davy’s friend -and biographer, happened to visit the laboratory while Faraday was at -work on these tubes. Seeing the oily liquid, he ventured to rally the -young assistant upon his carelessness in employing greasy tubes. Later -in the day, Faraday, on filing off the end of the tube, was startled by -finding the contents suddenly to explode; the oily matter completely -disappearing. He speedily ascertained the cause. The gas, liberated -from combination with water by heat, had under the pressure of its own -evolution liquefied itself, only to re-expand with violence when the -tube was opened. Early the next day Dr. Paris received the following -laconic note:-- - - DEAR SIR,-- - - The _oil_ you noticed yesterday turns out to be liquid chlorine. - - Yours faithfully, - M. FARADAY. - -Later he adopted a compressing syringe to condense the gas, and again -succeeded in liquefying it. Davy, who added a characteristic note to -Faraday’s published paper, immediately applied the same method of -liquefaction by its own pressure to hydrochloric acid gas; and Faraday -reduced a number of other gases by the same means. These researches -were not without danger. In the preliminary experiments an explosion -of one of the tubes drove thirteen fragments of glass into Faraday’s -eye. At the end of the year he drew up a historical statement on the -liquefaction of gases, which was published in the _Quarterly Journal_ -for January, 1824. A further statement by him was published in the -_Philosophical Magazine_ for 1836; and in 1844 his further researches -on the liquefaction of gases were published in the _Philosophical -Transactions_. - -In 1824 Faraday again brought to the Royal Society a chemical discovery -of first importance. The paper was on some new compounds of carbon and -hydrogen, and on certain other products obtained during decomposition -of oil by heat. From condensed oil-gas, so obtained, Faraday succeeded -in separating the liquid known as benzin or benzol, or, as he named it -at the time, bicarburet of hydrogen. It has since its discovery formed -the basis of several great chemical industries, and is manufactured in -vast quantities. Prior to the reading of this paper he had, as we have -already related, been elected a Fellow of the Royal Society, an honour -to which he had for some years aspired, and which stood alone in his -regard above the scientific honours of later years. - -In this year he tried, amongst his unsuccessful experiments, two of -singular interest. One was an attempt to find whether two crystals -(such as nitre) exercised upon one another any polar attractions like -those of two lodestones. He suspended them by fibres of cocoon silk, -and, finding this material not delicate enough, by spider-lines. The -other was an attempt to discover magneto-electricity. For various -reasons he concluded that the approximation of the pole of a powerful -magnet to a conductor carrying a current would have the effect of -diminishing the amount of that current. He placed magnets within a -copper wire helix, and observed with a galvanometer whether the current -sent through the circuit of the helix by a given battery was less when -the magnet was absent. The result was negative. - -[Sidenote: RESEARCH ON OPTICAL GLASS.] - -In this year also began the laborious researches on optical glass, -which though in themselves leading to no immediate success of -commercial value, nevertheless furnished Faraday with the material -essential at the time for the making of the most momentous of all -his discoveries. A committee had been appointed by the President and -Council of the Royal Society for the improvement of glass for optical -purposes, and Faraday was amongst those chosen to act upon it. - -In 1825 the Royal Society Committee delegated the investigation of -optical glass to a sub-committee of three, Herschel (afterwards -Sir John), Dollond (the optician), and Faraday. The chemical part, -including the experimental manufacture, was entrusted to Faraday. -Dollond was to work the glass and test its qualities from the -instrument maker’s point of view, whilst Herschel was to examine -its refraction, dispersion, and other physical properties. This -sub-committee worked for nearly five years, though by the removal of -Herschel from England its number was reduced to two. In 1827 the work -became more arduous. Faraday thus writes:-- - - The President and Council of the Royal Society applied to the - President and Managers of the Royal Institution for leave to - erect on their premises an experimental room with a furnace, - for the purpose of continuing the investigation on the - manufacture of optical glass. They were guided in this by the - desire which the Royal Institution has always evinced to assist - in the advancement of science; and the readiness with which the - application was granted showed that no mistaken notion had been - formed in this respect. As a member of both bodies, I felt much - anxiety that the investigation should be successful. A room - and furnaces were built at the Royal Institution in September, - 1827, and an assistant was engaged, Sergeant Anderson, of the - Royal Artillery. He came on the 3rd of December. - -Anderson, who was thus made assistant to Faraday, remained in that -capacity till his death in 1866. He was a most devoted servant. In a -footnote to the “Experimental Researches” (vol. iii. p. 3) Faraday in -1845 wrote of him:-- - - I cannot resist the occasion that is thus offered me of - mentioning the name of Mr. Anderson, who came to me as an - assistant in the glass experiments, and has remained ever since - in the laboratory of the Royal Institution. He assisted me in - all the researches into which I have entered since that time; - and to his care, steadiness, exactitude, and faithfulness in - the performance of all that has been committed to his charge, I - am much indebted.--M. F. - -Tyndall, who had a great admiration for Anderson, declared that -his merits as an assistant might be summed up in one phrase--blind -obedience. The story is told of him by Benjamin Abbott:-- - -[Sidenote: ANDERSON’S OBEDIENCE.] - - Sergeant Anderson ... was chosen simply because of the habits - of strict obedience his military training had given him. His - duty was to keep the furnaces always at the same heat, and the - water in the ashpit always at the same level. In the evening - he was released, but one night Faraday forgot to tell Anderson - he could go home, and early next morning he found his faithful - servant still stoking the glowing furnace, as he had been doing - all night long. - -The research on optical glass was viewed askance by several parties. -The expenditure of money which it involved was one of the “charges” -hurled against the Council of the Royal Society by Sir James South in -1830. Nevertheless it was deemed sufficiently important to receive -powerful support, as the following letter shows:-- - - Admiralty, 20 Dec., 1827. - - SIR, - - I hereby request, on behalf of the Board of Longitude, that you - will continue, in the furnace built at the Royal Institution, - the experiments on glass, directed by the joint Committee - of the Royal Society and the Board of Longitude and already - sanctioned by the Treasury and the Board of Excise. - - I am, Sir, - Your obedient servant, - THOMAS YOUNG, M.D., - Sec. Bd. Long. - - Michael Faraday, Esq., - Royal Institution. - - -In February, 1825, Faraday’s duties towards the Royal Institution were -somewhat modified. Hitherto he had been nominally a mere assistant -to Davy and Brande, though he had occasionally undertaken lectures -for the latter. Now, on Davy’s recommendation, he was, as we have -seen, appointed by the managers Director of the Laboratory under -the superintendence of the Professor of Chemistry. He was relieved, -“because of his occupation in research,” from his duty as chemical -assistant at the lectures. - -The research on optical glass was not concluded till 1829, when -its results were communicated to the Royal Society in the Bakerian -lecture of that year--a memoir so long that it is said three sittings -were occupied in its delivery. It is printed _in extenso_ in the -_Philosophical Transactions_ of 1830. It opens as follows:-- - - When the philosopher desires to apply glass in the construction - of perfect instruments, and especially the achromatic - telescope, its manufacture is found liable to imperfections so - important and so difficult to avoid, that science is frequently - stopped in her progress by them--a fact fully proved by the - circumstance that Mr. Dollond, one of our first opticians, has - not been able to obtain a disc of flint glass 4½ inches in - diameter, fit for a telescope, within the last five years; or a - similar disc, of 5 inches, within the last ten years. - - This led to the appointment by Sir H. Davy of the Royal Society - Committee, and the Government removed the excise restrictions, - and undertook to bear all the expenses as long as the - investigation offered a reasonable hope of success. - - The experiments were begun at the Falcon Glass Works, three - miles from the Royal Institution, and continued there in - 1825, 1826, and to Sept., 1827, when a room was built at the - Institution. At first the inquiry was pursued principally as - related to flint and crown glass; but in September, 1828, it - was directed exclusively to the preparation and perfection of - peculiar heavy and fusible glasses, from which time continued - progress has been made. - -In 1830 the experiments on glass-making were stopped. - -In 1831 the Committee for the Improvement of Glass for Optical -Purposes reported to the Royal Society Council that the telescope made -with Mr. Faraday’s glass had been examined by Captain Kater and Mr. -Pond. “It bears as great a power as can reasonably be expected, and is -very achromatic. The Committee therefore recommend that Mr. Faraday be -requested to make a perfect piece of glass of the largest size that -his present apparatus will admit, and also to teach some person to -manufacture the glass for general sale.” - -[Sidenote: GLASS-MAKING LAID ASIDE.] - -In answer to this Faraday sent the following letter to Dr. Roget, Sec. -R.S.:-- - - [_M. Faraday to P. M. Roget._] - - Royal Institution, July 4, 1831. - - DEAR SIR,--I send you herewith four large and two small - manuscript volumes relating to optical glass, and comprising - the journal book and sub-committee book, since the period that - experimental investigations commenced at the Royal Institution. - - With reference to the request which the Council of the - Royal Society have done me the honour of making--namely, - that I should continue the investigation--I should, under - circumstances of perfect freedom, assent to it at once; but - obliged as I have been to devote the whole of my spare time - to the experiments already described, and consequently to - resign the pursuit of such philosophical inquiries as suggested - themselves to my own mind, I would wish, under the present - circumstances, to lay the glass aside for a while, that I may - enjoy the pleasure of working out my own thoughts on other - subjects. - - If at a future time the investigation should be renewed, I must - beg it to be clearly understood I cannot promise full success - should I resume it: all that industry and my abilities can - effect shall be done; but to perfect a manufacture, not being a - manufacturer, is what I am not bold enough to promise. - - I am, &c., - M. FARADAY. - - -The optical glass was a failure, so far as concerned the original hope -that it would lead to great improvements in telescopes. Nevertheless -it furnished scientific men with a new material, the “heavy glass” -consisting essentially of boro-silicate of lead, for which sundry uses -in spectroscopy and other optical instruments have since been found. - -In 1845 Faraday added this note:-- - - I consider our results as negative, except as regards any - good that may have resulted from my heavy glass in the hands - of Amici (who applied it to microscopes) and in my late - experiments on light. - -These were the famous experiments on magneto-optics and diamagnetism. -Incidentally the research had led also to the permanent engagement of -Sergeant Anderson as assistant to Faraday. - -[Sidenote: RESEARCHES AND LECTURES.] - -During these years, from 1825 to 1829, which had been thus occupied in -an apparently fruitless quest, he had been far from idle. He had gone -on contributing chemical papers to the _Philosophical Transactions_ -and to the _Quarterly Journal_. These dealt with sulpho-naphthalic -acid, with the limits of vaporisation, with caoutchouc, bisulphide -of copper, the fluidity of sulphur and phosphorus, the diffusion of -gases, and the relation of water to hot polished surfaces. He had also -originated at the Royal Institution the Friday evening discourses (see -p. 33), the first of which he held in 1826. For some years he himself -delivered no inconsiderable portion of these discourses every session. -In 1826 he gave six, in 1827 three, in 1828 five, in 1829 six, and -these in addition to his regular afternoon courses of six or eight -lectures on some connected subject. He had also, in 1826, begun the -Christmas lectures adapted to a juvenile audience, and had in 1827 -given a course of twelve lectures at the London Institution in Finsbury -Circus. In addition to these labours he had, in 1827, brought out the -first edition of his book on “Chemical Manipulation.” In 1829 he began -his lectures at the Royal Military Academy at Woolwich, which continued -till 1849. - -The year 1830 may be regarded as the close of the first period of -Faraday’s researches, during which time, though much of his labour -had been of a preparatory and even desultory kind, it had been a -training for the higher work to come. He had made three notable -discoveries in chemistry, the new substances benzol and butylene, and -the solubility of naphthalene in sulphuric acid forming the first of a -new class of bodies, the sulpho-acids. He had also made an important -discovery in physics, that of the electromagnetic rotations. He had -already published sixty original papers, besides many notes of lesser -importance, nine of these papers being memoirs in the _Philosophical -Transactions_. He had already begun to receive from learned societies, -academies, and universities the recognition of his scientific -attainments, and he had established firmly both his own reputation as -a lecturer, and the reputation of the Royal Institution, which was the -scene of his lectures. - - - - -CHAPTER IV. - -SCIENTIFIC RESEARCHES: SECOND PERIOD. - - -With the year 1831 begins the period of the celebrated “Experimental -Researches in Electricity and Magnetism.” During the years which had -elapsed since his discovery of the electromagnetic rotations in 1823, -Faraday, though occupied, as we have seen, with other matters, had -not ceased to ponder the relation between the magnet and the electric -current. The great discoveries of Oersted, Ampère, and Arago had -culminated in England in two results: in Faraday’s discovery that the -wire which carries an electric current tends to revolve around the pole -of a neighbouring magnet; and in Sturgeon’s invention of the soft-iron -electromagnet, a core of iron surrounded by a coil of copper wire, -capable of acting as a magnet at will when the electric current is -transmitted to the coil and so caused to circulate around the iron core. - -[Sidenote: FORESHADOWINGS.] - -This production of magnetism from electricity, at will, and at a -distance, by the simple device of sending the electricity to circulate -as a current around the central core of iron was then, as now, a cause -of much speculation. The iron core which is to be made temporarily -into a magnet stands alone, isolated. Though surrounded outwardly -by the magnetising coil of copper wire, it does not touch it; nay, -must be screened from contact with it by appropriate insulation. The -electric current entering the copper coil at one end is confined from -leaving the copper wire by any lateral path: it must circulate around -each and every convolution, nor be permitted to flow back by the -return-wire until it has performed the required amount of circulation. -That the mere external circulation of electric current around a totally -disconnected interior core of iron should magnetise that core; that -the magnetisation should be maintained so long as the circulation of -electricity is maintained; and that the magnetising forces should cease -so soon as the current is stopped, are facts, familiar enough to every -beginner in the science, but mysterious enough from the abstract point -of view. Faraday was firmly persuaded that, great as had been these -discoveries of the production of magnetism and magnetic motions from -electricity, there remained other relations of no less importance to -be discovered. Again and again his mind recurred to the subject. If it -were possible to use electricity to produce magnetism, why should not -the converse be true? In 1822 his notebook suggestion was, as we have -seen, “Convert magnetism into electricity.” Yes, but how? - -He possessed an intuitive bent of mind to inquire about the relations -of facts to one another. Convinced by sheer converse with nature in -the laboratory, of the correlation of forces and of the conservation -of energy long before either of those doctrines had received distinct -enunciation as principles of natural philosophy, he seems never to -have viewed an action without thinking of the necessary and appropriate -reaction; never to have deemed any physical relation complete in -which discovery had not been made of the converse relations for -which instinctively he sought. So in December, 1824, we find him -experimenting on the passage of a bar magnet through a helix of copper -wire (see _Quarterly Journal_ for July, 1825), but without result. In -November, 1825, he sought for evidence that might prove an electric -current in a wire to exercise an influence upon a neighbouring wire -connected to a galvanometer. But again, and yet again in December -of the same year, the entry stands “No result.” A third failure did -not convince him that the search was hopeless: it showed him that he -had not yet found the right method of experimenting. It is narrated -of him how at this period he used to carry in his waistcoat pocket a -small model of an electromagnetic circuit--a straight iron core about -an inch long, surrounded by a few spiral turns of copper wire--which -model he at spare moments would take out and contemplate, using it thus -objectively to concentrate his thoughts upon the problem to be solved. -A copper coil, an iron core. Given that electricity was flowing through -the one, it evoked magnetism in the other. What was the converse? -At first sight it might seem simple enough. Put magnetism from some -external source into the iron core, and then try whether on connecting -the copper coil to a galvanometer there was any indication of an -electric current. But this was exactly what was found not to result. - -[Sidenote: OTHER MEN’S FAILURES.] - -And not Faraday alone, but others, too, were foiled in the hope of -observing the expected converse. Not all who tried were as wise or -as frank as Faraday in confessing failure. Fresnel, in the height of -the fever of Oersted’s discovery, had announced to the Academy of -Sciences at Paris, on the 6th of November, 1820, that he had decomposed -water by means of a magnet which was laid motionless within a spiral -of wire. Emboldened by this announcement, Ampère remarked that he -too had noticed something in the way of production of currents from -a magnet. But before the end of the year both these statements were -withdrawn by their authors. Again, in the year 1822, Ampère, being at -Geneva, showed to Professor A. de la Rive in his laboratory a number of -electromagnetic experiments from his classical researches; and amongst -them one[20] which has been almost forgotten, but which, had it been -followed up, would assuredly have led Ampère to the discovery of the -induction of currents. In the experiment in question a thin copper -ring, made of a narrow strip folded into a circle, was hung inside -a circular coil of wire, traversed by a current. To this apparatus -a powerful horse-shoe magnet was presented; and De la Rive states -that, when the magnet was brought up, the suspended ring was observed -sometimes to move between the two limbs of the magnet, and sometimes -to be repelled from between them according to the sense of the current -in the surrounding coil. He and Ampère both attributed the effect to -temporary magnetism conferred upon the copper ring. Ampère himself -was at the time disposed to attribute it to the possible presence of -a little iron as an impurity in the copper. There are, however, some -discrepancies in the three published versions of the story. According -to Becquerel, Ampère had by 1825 satisfied himself of the non-existence -of induction currents. - -[Sidenote: A PUZZLING EXPERIMENT.] - -Quite independently, the question of the possibility of creating -currents by magnets was raised by another discovery, that of the -so-called “magnetism of rotation.” In 1824 Arago had observed that -a fine magnetic compass constructed for him by Gambey, having the -needle suspended in a cell, the base of which was a plate of pure -copper, was thereby damped in its oscillations, and instead of making -two or three hundred vibrations before it came to rest, as would be -the case in the open air, executed only three or four of rapidly -decreasing amplitude.[21] In vain did Dumas at the request of Arago -analyse the copper, in the supposition that iron might be present. -Inquiry compelled the conclusion that some other explanation must be -sought. And, reasoning from the apparent action of stationary copper -in bringing a moving magnetic needle to rest, he conjectured that a -moving mass of copper might produce motion in a stationary magnetic -needle. Accordingly he set into revolution, beneath a compass needle, -a flat disc of copper, and found that, even when a sheet of card or -glass was interposed to cut off all air-currents, the needle tended to -follow the moving copper disc, turning as if dragged by some invisible -influence. To the suggestion that mere rotation conferred upon copper -a sort of temporary magnetism Arago listened with some impatience. All -theories proposed to account for the phenomenon he discredited, even -though emanating from the great mathematician Poisson. He held his -judgment in absolute suspense. Babbage and Herschel measured the amount -of retarding force exerted on the needle by different materials, and -found the most effective to be silver and copper (which are the two -best conductors of electricity), after them gold and zinc, whilst lead, -mercury, and bismuth were inferior in power. The next year the same -experimenters announced the successful inversion of Arago’s experiment; -for by spinning the magnet underneath a pivoted copper disc they caused -the latter to rotate briskly. They also made the notable observation -that if slits are cut radially in the copper disc they diminish its -tendency to be dragged by the spinning magnet. Sturgeon showed that -the damping effect of a moving copper disc was diminished by the -presence of a second magnet pole of contrary kind placed beside the -first. All these things were most suggestive of the real explanation. -It clearly had something to do with the electric conductivity of -the metal disc, and therefore with electric currents. Sturgeon five -years later came very near to the explanation: after repeating the -experiments he concluded that the effect was an electric disturbance -in the copper disc, “a kind of reaction to that which takes place in -electromagnetism.” - -Faraday knew of all the discussions which had arisen respecting -Arago’s rotations. They may have been the cause of his unsuccessful -attempts of 1824 and 1825. In April, 1828, for the fourth time he tried -to discover the currents which he was convinced must be producible -by the magnet, and for the fourth time without result. The cause of -failure was that both magnet and coil were at rest. - -[Illustration: FIG. 4.] - -The summer of 1831 witnessed him for the fifth time making the attack -on the problem thus persistently before him. In his laboratory -note-book he heads the research “Experiments on the production of -electricity from magnetism.” The following excellent summary of the -laboratory notes is taken from Bence Jones’s “Life and Letters”:-- - - I have had an iron ring made (soft iron), iron round and ⅞ths - of an inch thick, and ring six inches in external diameter. - Wound many coils of copper round, one half of the coils being - separated by twine and calico; there were three lengths of - wire, each about twenty-four feet long, and they could be - connected as one length, or used as separate lengths. By trials - with a trough each was insulated from the other. Will call - this side of the ring A. On the other side, but separated by - an interval, was wound wire in two pieces, together amounting - to about sixty feet in length, the direction being as with the - former coils. This side call B.[22] - - Charged a battery of ten pairs of plates four inches square. - Made the coil on B side one coil, and connected its extremities - by a copper wire passing to a distance, and just over a - magnetic needle (three feet from wire ring), then connected the - ends of one of the pieces on A side with battery: immediately - a sensible effect on needle. It oscillated and settled at last - in original position. On breaking connection of A side with - battery, again a disturbance of the needle. - -[Sidenote: SUCCESS IN SIGHT.] - -In the seventeenth paragraph, written on the 30th of August, he says, -“May not these transient effects be connected with causes of difference -between power of metals at rest and in motion in Arago’s experiments?” -After this he prepared fresh apparatus. - -As was his manner, he wrote off to one of his friends a letter telling -what he was at work upon. On this occasion the recipient of his -confidences was his friend Phillips:-- - - [_Michael Faraday to Richard Phillips._] - - Royal Institution. - Sept. 23, 1831. - - MY DEAR PHILLIPS, - - I write now, though it may be some time before I send my - letter, but that is of no great consequence. I received your - letter to Dr. Reid and read it on the coach going to Hastings, - where I have been passing a few weeks, and I fancy my fellow - passengers thought I had got something very droll in hand; - they sometimes started at my sudden bursts, especially when I - had the moment before been very grave and serious amongst the - proportions. As you say in the letter there are some new facts - and they are always of value; otherwise I should have thought - you had taken more trouble than the matter deserved. Your - quotation from Boyle has nevertheless great force in it. - - I shall send with this a little thing in your own way “On the - Alleged decline of science in England.” It is written by Dr. - Moll of Utrecht, whose name may be mentioned in conversation - though it is not printed in the pamphlet. I understand the - view taken by Moll is not at all agreeable to some. “I do not - know what business Moll had to interfere with our scientific - disputes” is however the strongest observation I have heard of - in reply. - - I do not think I thanked you for your last Pharmacopœia. I - do so now very heartily. I shall detain this letter a few - days that I may send a couple of my papers (_i.e._ a paper - and appendix) with it, for though not chemical I think - you will like to have them. I am busy just now again on - Electro-Magnetism, and think I have got hold of a good thing, - but can’t say; it may be a weed instead of a fish that after - all my labour I may at last pull up. I think I know why metals - are magnetic when in motion though not (generally) when at rest. - - We think about you all very much at times, and talk over - affairs of Nelson Square, but I think we dwell more upon the - illnesses and nursings and upon the sudden calls and chats - rather than the regular parties. Pray remember us both to Mrs. - Phillips and the damsils--I hope the word is not too familiar. - - I am Dear Phillips, - Most Truly Yours, - M. FARADAY. - - R. Phillips, Esq., - &c., &c., &c. - - -[Sidenote: TEN DAYS OF SPLENDID WORK.] - -September 24 was the third day of his experiments. He began (paragraph -21) by trying to find the effect of one helix of wire, carrying the -voltaic current of ten pairs of plates, upon another wire connected -with a galvanometer. “No induction sensible.” Longer and different -metallic helices (paragraph 22) showed no effect; so he gave up those -experiments for that day, and tried the effects of bar magnets instead -of the ring magnet he had used on the first day. - -[Illustration: FIG. 5.] - -In paragraph 33 he says:-- - - An iron cylinder had a helix wound on it. The ends of the wires - of the helix were connected with the indicating helix at a - distance by copper wire. Then the iron placed between the poles - of bar magnets as in accompanying figure (Fig. 5). Every time - the magnetic contact at N or S was made or broken, there was - magnetic motion at the indicating helix--the effect being, as - in former cases, not permanent, but a mere momentary push or - pull. But if the electric communication (_i.e_. by the copper - wire) was broken, then the disjunction and contacts produced no - effect whatever. Hence here distinct conversion of magnetism - into electricity. - -The fourth day of work was October 1. Paragraphs 36, 37, and 38 -describe the discovery of induced voltaic currents:-- - - 36. A battery of ten troughs, each of ten pairs of plates four - inches square, charged with good mixture of sulphuric and - nitric acid, and the following experiments made with it in the - following order. - - 37. One of the coils (of a helix of copper wire 203 feet long) - was connected with the flat helix, and the other (coil of same - length round same block of wood) with the poles of the battery - (it having been found that there was no metallic contact - between the two); the magnetic needle at the indicating flat - helix was affected, but so little as to be hardly sensible. - - 38. In place of the indicating helix, our galvanometer was - used, and then a sudden jerk was perceived when the battery - communication was _made_ and _broken_, but it was so slight as - to be scarcely visible. It was one way when made, the other - when broken, and the needle took up its natural position at - intermediate times. - - Hence there is an inducing effect without the presence of iron, - but it is either very weak or else so sudden as not to have - time to move the needle. I rather suspect it is the latter. - -The fifth day of experiment was October 17. Paragraph 57 describes the -discovery of the production of electricity by the approximation of a -magnet to a wire:-- - - A cylindrical bar magnet three-quarters of an inch in - diameter, and eight inches and a half in length, had one end - just inserted into the end of the helix cylinder (220 feet - long); then it was quickly thrust in the whole length, and the - _galvanometer_ needle moved; then pulled out, and again the - _needle moved_, but in the opposite direction. This effect was - repeated every time the magnet was put in or out, and therefore - a wave of electricity was so produced from _mere approximation - of a magnet_, and not from its formation _in situ_. - -The cause of all the earlier failures was, then, that both magnet and -coil were at rest. The magnet might lie in or near the coil for a -century and cause no effect. But while moving towards the coil, or from -it, or by spinning near it, electric currents were at once induced. - -The ninth day of his experiments was October 28, and this day -he “made a copper disc turn round between the poles of the great -horse-shoe magnet of the Royal Society. The axis and edge of the disc -were connected with a galvanometer. The needle moved as the disc -turned.” The next day that he made experiments, November 4, he found -“that a copper wire one-eighth of an inch drawn between the poles and -conductors produced the effect.” In his paper, when describing the -experiment, he speaks of the metal “cutting” the magnetic curves, and -in a note to his paper he says, “By magnetic curves I mean lines of -magnetic forces which would be depicted by iron filings.” - -[Sidenote: SUCCESS AND ITS SECRET.] - -We here come upon those “lines of force” which played so important a -part in these and many of Faraday’s later investigations. They were -known before Faraday’s time--had, in fact, been known for two hundred -years. Descartes had seen in them evidence for his hypothetical -vortices. Musschenbroek had mapped them. But it was reserved to Faraday -to point out their true significance. To the very end of his life he -continued to speculate and experiment upon them. - -All this splendid work had occupied but a brief ten days. Then he -rearranged the facts which he had thus harvested, and wrote them out in -corrected form as the first series of his “Experimental Researches in -Electricity.” The memoir was read to the Royal Society on November 24, -1831, though it did not appear in printed form until January, 1832--a -delay which gave rise to serious misunderstandings. The paper having -been read, he went away to Brighton to take a holiday, and in the -exuberance of his heart penned the following letter[23] to Phillips:-- - - [_M. Faraday to R. Phillips._] - - Brighton: November 29, 1831. - - DEAR PHILLIPS,--For once in my life I am able to sit down and - write to you without feeling that my time is so little that my - letter must of necessity be a short one and accordingly I have - taken an extra large sheet of paper intending to fill it with - news and yet as to news I have none for I withdraw more and - more from Society, and all I have to say is about myself. - - But how are you getting on? are you comfortable? and how does - Mrs. Phillips do; and the girls? Bad correspondant as I am, I - think you owe me a letter and as in the course of half an hour - you will be doubly in my debt pray write us, and let us know - all about you. Mrs. Faraday wishes me not to forget to put her - kind remembrances to you and Mrs. Phillips in my letter. - - To-morrow is St. Andrew’s day,[24] but we shall be here until - Thursday. I have made arrangements to be _out_ of the Council - and care little for the rest although I should as a matter of - curiosity have liked to see the Duke in the chair on such an - occasion. - - We are here to refresh. I have been working and writing a - paper and that always knocks me up in health, but now I feel - well again and able to pursue my subject and now I will tell - you what it is about. The title will be, I think, EXPERIMENTAL - RESEARCHES IN ELECTRICITY: §I. _On the induction of electric - currents._ § II. _On the evolution of Electricity from - magnetism._ § III. _On a New electrical condition of matter._ - § IV. _On Arago’s magnetic phenomena._ There is a bill of fare - for you; and what is more I hope it will not disappoint you. - Now the pith of all this I must give you very briefly; the - demonstrations you shall have in the paper when printed-- - - [Sidenote: THE PITH OF THE DISCOVERY.] - - § I. When an electric current is passed through one of two - parallel wires it causes at first a current in the same - direction[25] through the other, but this induced current does - not last a moment, notwithstanding the inducing current (from - the Voltaic battery) is continued all seems unchanged except - that the principal current continues its course, but when the - current is stopped then a return current occurs in the wire - under induction of about the same intensity and momentary - duration but in the opposite direction to that first found. - Electricity in currents therefore exerts an inductive action - like ordinary electricity but subject to peculiar laws: the - effects are a current in the same direction when the induction - is established: a reverse current when the induction ceases and - a _peculiar state_ in the interim. Common electricity probably - does the same thing but as it is at present impossible to - separate the beginning and the end of a spark or discharge from - each other, all the effects are simultaneous and neutralise - each other-- - - § II. Then I found that magnets would induce just like voltaic - currents and by bringing helices and wires and jackets up to - the poles of magnets, electrical currents were produced in - them these currents being able to deflect the galvanometer, or - to make, by means of the helix, magnetic needles, or in one - case even to give a spark. Hence the evolution of _electricity - from magnetism_. The currents were not permanent, they ceased - the moment the wires ceased to approach the magnet because - the new and apparently quiescent state was assumed just as in - the case of the induction of currents. But when the magnet - was removed, and its induction therefore ceased, the return - currents appeared as before. These two kinds of induction - I have distinguished by the terms _Volta-electric_ and - _Magneto-electric_ induction. Their identity of action and - results is, I think, a very powerful proof of the truth of M. - Ampère’s theory of magnetism. - - [Sidenote: A JUBILANT EPISTLE.] - - § III. The new electrical condition which intervenes by - induction between the beginning and end of the inducing current - gives rise to some very curious results. It explains why - chemical action or other results of electricity have never - been as yet obtained in trials with the magnet. In fact, the - currents have no sensible duration. I believe it will explain - perfectly the _transference of elements_ between the poles - of the pile in decomposition but this part of the subject I - have reserved until the present experiments are completed - and it is so analogous, in some of its effects to those of - Ritter’s secondary piles, De la Rive and Van Beck’s peculiar - properties of the poles of a voltaic pile, that I should - not wonder if they all proved ultimately to depend on this - state. The condition of matter I have dignified by the term - _Electrotonic_, THE ELECTROTONIC STATE. What do you think of - that? Am I not a bold man, ignorant as I am, to coin words - but I have consulted the scholars,[26] and now for § IV. The - new state has enabled me to make out and explain all Arago’s - phenomena of the rotating magnet or copper plate, I believe, - perfectly; but as great names are concerned Arago, Babbage, - Herschel, &c., and as I have to differ from them, I have spoken - with that modesty which you so well know you and I and John - Frost[27] have in common, and for which the world so justly - commends us. I am even half afraid to tell you what it is. - You will think I am hoaxing you, or else in your compassion - you may conclude I am deceiving myself. However, you need do - neither, but had better laugh, as I did most heartily when I - found that it was neither attraction nor repulsion, but just - one of _my old rotations_ in a new form. I cannot explain to - you all the actions, which are very curious; but in consequence - of the electrotonic state being assumed and lost as the - parts of the plate whirl under the pole, and in consequence - of magneto-electric induction, currents of electricity are - formed in the direction of the radii; continuing, for simple - reasons, as long as the motion continues, but ceasing when - that ceases. Hence the wonder is explained that the metal has - powers on the magnet when moving, but not when at rest. Hence - is also explained the effect which Arago observed, and which - made him contradict Babbage and Herschel, and say the power - was repulsive; but, as a whole, it is really tangential. It - is quite comfortable to me to find that experiment need not - quail before mathematics, but is quite competent to rival - it in discovery; and I am amused to find that what the high - mathematicians have announced as the _essential condition_ - to the rotation--namely, that _time is required_--has so - little foundation, that if the time could by possibility be - anticipated instead of being required--_i.e._ if the currents - could be formed _before_ the magnet came over the place instead - of _after_--the effect would equally ensue. Adieu, dear - Phillips. - - Excuse this egotistical letter from yours very faithfully, - - M. FARADAY. - - -The second section shows that Faraday had discovered the cause of all -the previous failures to evoke electric currents in wires by means of a -magnet: it required _relative motion_. What the magnet at rest fails to -do, the magnet in motion accomplishes. This crucial point is admirably -commemorated in the following impromptu given by Mr. Herbert Mayo to -Sir Charles Wheatstone:-- - - Around the magnet Faraday - Was sure that Volta’s lightnings play: - But how to draw them from the wire? - He took a lesson from the heart: - ’Tis when we meet, ’tis when we part, - Breaks forth the electric fire. - -Faraday’s holiday was brief; by December 5 he was again at work on his -researches. He re-observed the directions of the induced currents about -which, as the slip in his letter to Phillips shows, his mind was in -some doubt. Then on December 14th comes the entry:--“Tried the effects -of terrestrial magnetism in evolving electricity. Obtained beautiful -results.” - -“The helix had the soft iron cylinder (freed from magnetism by a full -red heat and cooling slowly) put into it, and it was then connected -with the galvanometer by wires eight foot long; then inverted the bar -and helix, and immediately the needle moved; inverted it again, the -needle moved back; and, by repeating the motion with the oscillations -of the needle, made the latter vibrate 180°, or more.” - -The same day he “made Arago’s experiment with the earth magnet, only no -magnet used, but the plate put horizontal and rotated. The effect at -the needle was slight but very distinct.... Hence Arago’s plate a new -electrical machine.” - -[Sidenote: POINTS IN THE DISCOVERY.] - -When we compare these manuscript notes, recording the experiments in -the order in which they were made with the published account of them -in the “Experimental Researches,” we find many of them transcribed -almost verbatim. But there is a difference in the order of their -arrangement. In point of time the experiments on the evolution of -electricity from magnetism, beginning with the ring (p. 108), preceded -those on the induction of a current by another current. In the printed -“Researches” the experiments on the induction of currents are put -first, with an introductory paragraph on the general phenomenon of -induction.[28] Faraday’s habit of working up an experiment--whether -successful or unsuccessful--by increasing the power to the maximum -available is illustrated in the course of the experiments on the iron -ring. At first he used a battery of ten pairs of plates four inches -square. Then, having been eminently successful in producing deflexions -of his galvanometer, he increased the battery to one hundred pairs of -plates, with the result that when contact was completed or broken in -the primary circuit the impulse on the galvanometer in the secondary -circuit was so great as to make the needle spin round rapidly four -or five times before its motion was reduced to a mere oscillation. -Then he removed the galvanometer and fixed small pencils of charcoal -to the ends of the secondary helix; and to his great joy perceived a -minute _spark_ between the lightly touching charcoal points whenever -the contact of the battery to the primary helix was completed. This -was the first transformer, for the first time set--on a small -scale--to produce a tiny electric light. The spark he regarded as a -precious indication that what he was producing really was an electric -current. Using the great compound steel magnet of the Royal Society -(constructed by Dr. Gowin Knight) at Christie’s house at Woolwich -he had, as narrated above, also obtained a spark from the induced -current. For some time he failed to obtain either physiological or -chemical effects. But upon repeating the experiments more at leisure -at the Royal Institution, with Daniell’s armed loadstone capable of -lifting thirty pounds, a frog was found to be convulsed very strongly -each time magnetic contact between the magnet and the iron core of the -experimental coil was made or broken. - -The absence of evidence as to chemical action seemed still to -disquiet him. He wanted to be sure that his induced currents would -do everything that ordinary voltaic currents would do. Failing the -final proof from chemical action, he rested the case on the other -identical properties. “But an agent,” he says, “which is conducted -along metallic wires in the manner described; which, whilst so passing, -possesses the peculiar magnetic actions and force of a current of -electricity; which can agitate and convulse the limbs of a frog; -and which, finally, can produce a spark by its discharge through -charcoal, can only be electricity. As all the effects can be produced -by ferruginous electro-magnets, there is no doubt that arrangements -like the magnets of Professors Moll, Henry, Ten Eyke, and others, in -which as many as two thousand pounds have been lifted, may be used -for these experiments; in which case not only a brighter spark may be -obtained, but wires also ignited, and as the currents can pass liquids, -chemical action be produced. These effects are still more likely to -be obtained when the magneto-electric arrangements, to be explained -in the fourth section, are excited by the powers of such apparatus.” -The apparatus described in the fourth section comprised several forms -of magneto-electric machines, that is to say, primitive kinds of -dynamos. Having in his mind the phenomenon discovered by Arago, and -the experiments of Babbage and Herschel on the so-called magnetism of -rotation, he followed up the idea that these effects might be due to -induced currents eddying round in the copper disc. No sooner had he -obtained electricity from magnets than he attempted to make Arago’s -experiment a new source of electricity, and, as he himself says, “did -not despair” “of being able to construct a new electrical machine.” - -[Illustration: FIG. 6. (FACSIMILE OF ORIGINAL SKETCH.)] - -[Sidenote: A NEW ELECTRICAL MACHINE.] - -The “new electrical machine” was an exceedingly simple contrivance. A -disc of copper, twelve inches in diameter (Fig. 6), and about one-fifth -of an inch in thickness, fixed upon a brass axle, was mounted in -frames, so as to allow of revolution, its edge being at the same time -introduced between the magnetic poles of a large compound permanent -magnet, the poles being about half an inch apart.[29] The magnet first -used was the historical magnet of Gowin Knight. The edge of the plate -was well amalgamated, for the purpose of obtaining a good but movable -contact, and a part round the axle was also prepared in a similar -manner. Conducting strips of copper and lead, to serve as electric -collectors, were prepared, so as to be placed in contact with the edge -of the copper disc; one of these was held by hand to touch the edge -of the disc between the magnet poles. The wires from a galvanometer -were connected, the one to the collecting-strip, the other to the -brass axle; then on revolving the disc a deflexion of the galvanometer -was obtained, which was reversed in direction when the direction of -the rotation was reversed. “Here, therefore, was demonstrated the -production of a permanent current of electricity by ordinary magnets.” -These effects were also obtained from the poles of electro-magnets, -and from copper helices without iron cores. Several other forms of -magneto-electric machines were tried by Faraday. - -[Sidenote: NEW FORMS OF APPARATUS.] - -[Illustration: FIG. 7.] - -In one,[30] a flat ring of twelve inches’ external diameter, and one -inch broad, was cut from a thick copper plate, and mounted to revolve -between the poles of the magnet, two conductors being applied to -make rubbing contact at the inner and outer edge at the part which -passed between the magnetic poles. In another,[31] a disc of copper, -one-fifth of an inch thick and only 1½ inch in diameter (Fig. 7), was -amalgamated at the edge, and mounted on a copper axle. A square piece -of sheet metal had a circular hole cut in it, into which the disc -fitted loosely; a little mercury completed communication between the -disc and its surrounding ring. The latter was connected by wire to a -galvanometer; the other wire being connected from the instrument to the -end of the axle. Upon rotating the disc in a horizontal plane, currents -were obtained, though the earth was the only magnet employed. - -[Illustration: FIG. 8.] - -Faraday also proposed a multiple machine[32] having several discs, -metallically connected alternately at the edges and centres by means -of mercury, which were then to be revolved alternately in opposite -directions, In another apparatus,[33] a copper cylinder (Fig. 8), -closed at one extremity, was put over a magnet, one half of which -it enclosed like a cap, and to which it was attached without making -metallic contact. The arrangement was then floated upright in a narrow -jar of mercury, so that the lower edge of the copper cap touched the -fluid. On rotating the magnet and its attached cap, a current was sent -through wires from the mercury to the top of the copper cap. In another -apparatus,[34] still preserved at the Royal Institution, a cylindrical -bar magnet, half immersed in mercury, was made to rotate, and generated -a current, its own metal serving as a conductor. In another form,[35] -the cylindrical magnet was rotated horizontally about its own axis, and -was found to generate currents which flowed from the middle to the -ends, or _vice versâ_, according to the rotation. The description of -these new electrical machines is concluded with the following pregnant -words:-- - -[Sidenote: AN EARTH-INDUCTOR.] - - I have rather, however, been desirous of discovering new facts - and relations dependent on magneto-electric induction, than of - exalting the force of those already obtained; being assured - that the latter would find their full development hereafter. - -[Illustration: FIG. 9.] - -In yet another machine (Fig. 9), constructed by Faraday some time -later,[36] a simple rectangle of copper wire _w_, attached to a frame, -was rotated about a horizontal axis placed east and west, and generated -alternate currents, which could be collected by a simple commutator _c_. - -Within a few months machines on the principle of magneto-induction had -been devised by Dal Negro, and by Pixii. In the latter’s apparatus a -steel horseshoe magnet, with its poles upwards, was caused to rotate -about a vertical shaft, inducing alternating currents in a pair of -bobbins fixed above it, and provided with a horseshoe core of soft -iron. Later, in 1832, Pixii produced, at the suggestion of Ampère,[37] -a second machine, provided with mercury cup connections to rectify the -alternations of the current. One of these machines was shown at the -British Association meeting at Oxford in the same year (p. 64). - -The idea developed in the third part of this research was intensely -original and suggestive. Faraday’s own statement is as follows:-- - -[Sidenote: THE ELECTROTONIC STATE.] - - Whilst the wire is subject to either volta-electric or - magneto-electric induction, it appears to be in a peculiar - state; for it resists the formation of an electrical current - in it, whereas, if left in its common condition, such a - current would be produced; and when left uninfluenced it has - the power of originating a current, a power which the wire - does not possess under common circumstances. This electrical - condition of matter has not hitherto been recognised, but it - probably exerts a very important influence in many, if not - most, of the phenomena produced by currents of electricity. For - reasons which will immediately appear, I have, after advising - with several learned friends, ventured to designate it as the - _electrotonic_ state. - - This peculiar condition shows no known electrical effects - whilst it continues; nor have I yet been able to discover any - peculiar powers exerted or properties possessed by matter - whilst retained in this state. - - * * * * * - - This state is altogether the effect of the induction exerted, - and ceases as soon as the inductive force is removed.... The - state appears to be instantly assumed, requiring hardly a - sensible portion of time for that purpose.... In all those - cases where the helices or wires are advanced towards or taken - from the magnet, the direct or inverted current of induced - electricity continues for the time occupied in the advance or - recession; for the electro-tonic state is rising to a higher or - falling to a lower degree during that time, and the change is - accompanied by its corresponding evolution of electricity; but - these form no objections to the opinion that the electro-tonic - state is instantly assumed. - - This peculiar state appears to be a state of tension, and may - be considered as _equivalent_ to a current of electricity, - at least equal to that produced either when the condition is - induced or destroyed. - -Faraday further supposed that the formation of this state in the -neighbourhood of a coil would exert a reaction upon the original -current, giving rise to a retardation of it; but he was unable at -the time to ascertain experimentally whether this was so. He even -looked--though also unsuccessfully--for a self-induced return current -from a conductor of copper through which a strong current was led and -then suddenly interrupted, the expected current of reaction being “due -to the discharge of its supposed electrotonic state.” - -If we would understand the rather obscure language in which this idea -of an electrotonic state is couched, we must try to put ourselves -back to the epoch when it was written. At that date the only ideas -which had been formulated to explain magnetic and electric attractions -and repulsions were founded upon the notion of action at a distance. -Michell had propounded the view that the electric and magnetic forces -vary, like gravity, according to a law of the inverse squares of the -distances. Coulomb, in a series of experiments requiring extraordinary -patience as well as delicacy of manipulation, had shown--by an -application of Michell’s torsion balance--that in particular cases -where the electric charges are concentrated on small spheres, or -where the magnetic poles are small, so as to act as mere points, -this law--which is essentially a geometric law of point-action--is -approximately fulfilled. The mathematicians, Laplace and Poisson at -their head, had seized on this demonstration and had elaborated their -mathematical theories. Before them, though the research lay for a -century unpublished, Cavendish had shown that the only law of force -as between one element of an electric charge and another compatible -with a charge being in equilibrium was the law of inverse squares. -But in all these mathematical reasonings one thing had been quite -left out of sight--namely, the possible properties of the intervening -medium. Faraday, to whom the idea of mere action at a distance was -abhorrent, if not unthinkable, conceived of all these forces of -attraction and repulsion as effects taking place by something going -on _in the intervening medium_, as effects propagated from point -to point continuously through space. In his earlier work on the -electromagnetic rotations he had grown to regard the space around -the conducting wire as being affected by the so-called current; and -the space about the poles of a magnet he knew to be traversed by -curved magnetic lines, invisible indeed, but real, needing only the -simplest of expedients--the sprinkling of iron filings--to reveal their -existence and trend. When therefore he found that these new effects of -the induction of one electric current by another could likewise cross -an intervening space, whether empty or filled with material bodies, -he instinctively sought to ascribe this propagation of the effect -to a property or state of the medium. And finding that state to be -different from any state previously known, different from the state -existing between two magnets at rest or between two stationary electric -charges, he followed the entirely philosophical course of exploring its -properties and of denoting it by a name which he deemed appropriate. As -we shall see, this idea of an electrotonic state recurred in his later -researches with new and important connotations. - -[Illustration: FIG. 10.] - -He was soon at work again, as we have seen. - -He experimented, in January, 1832, on the currents produced by the -earth’s rotation--on the 10th at the round pond in Kensington Gardens, -and on the 12th and 13th at Waterloo Bridge. - -[Sidenote: A SPARK FROM A MAGNET.] - -“This evening,” he writes in his notebook under date February 8, “at -Woolwich, experimenting with magnet,[38] and for the first time got the -magnetic spark myself. Connected ends of a helix into two general ends, -and then crossed the wires in such a way that a blow at _a b_ would -open them a little [Fig. 10]. Then bringing _a b_ against the poles of -a magnet, the ends were disjoined, and bright sparks resulted.” - -From succeeding with a steel magnet it was but a short step to -succeed when a natural loadstone was used. The next day we find this -entry:--“At home succeeded beautifully with Mr. Daniell’s magnet. -Amalgamation of wires very needful. This is a natural loadstone, and -perhaps the first used for the spark.” - -He sent to the Royal Society an account of these and the earlier -experiments; his paper on terrestrial magneto-electric induction, and -on the force and direction of magneto-electric induction, received the -distinction of being read as the Bakerian lecture of the year. - -[Sidenote: TYNDALL’S SUMMARY.] - -The following summary of this second paper is from the pen of Professor -Tyndall:-- - - He placed a bar of iron in a coil of wire, and lifting the - bar into the direction of the dipping needle, he excited by - this action a current in the coil. On reversing the bar, a - current in the opposite direction rushed through the wire. - The same effect was produced, when, on holding the helix in - the line of dip, a bar of iron was thrust into it. Here, - however, the earth acted on the coil through the intermediation - of the bar of iron. He abandoned the bar, and simply set a - copper plate spinning in a horizontal plane; he knew that the - earth’s lines of magnetic force then crossed the plate at an - angle of about 70°. When the plate spun round, the lines of - force were intersected and induced currents generated, which - produced their proper effect when carried from the plate to the - galvanometer. “When the plate was in the magnetic meridian, or - in any other plane coinciding with the magnetic dip, then its - rotation produced no effect upon the galvanometer.” - - At the suggestion of a mind fruitful in suggestions of a - profound and philosophic character--I mean that of Sir John - Herschel--Mr. Barlow, of Woolwich, had experimented with - a rotating iron shell. Mr. Christie had also performed an - elaborate series of experiments on a rotating iron disc. Both - of them had found that when in rotation the body exercised a - peculiar action upon the magnetic needle, deflecting it in a - manner which was not observed during quiescence; but neither - of them was aware at the time of the agent which produced this - extraordinary deflection. They ascribed it to some change in - the magnetism of the iron shell and disc. - - But Faraday at once saw that his induced currents must come - into play here, and he immediately obtained them from an iron - disc. With a hollow brass ball, moreover, he produced the - effects obtained by Mr. Barlow. Iron was in no way necessary; - the only condition of success was that the rotating body - should be of a character to admit of the formation of currents - in its substance; it must, in other words, be a conductor of - electricity. The higher the conducting power, the more copious - were the currents. He now passes from his little brass globe - to the globe of the earth. He plays like a magician with the - earth’s magnetism. He sees the invisible lines along which - its magnetic action is exerted, and, sweeping his wand across - these lines, he evokes this new power. Placing a simple loop - of wire round a magnetic needle, he bends its upper portion - to the west; the north pole of the needle immediately swerves - to the east; he bends his loop to the east, and the north - pole moves to the west. Suspending a common bar magnet in a - vertical position, he causes it to spin round its own axis. - Its pole being connected with one end of a galvanometer wire, - and its equator with the other end, electricity rushes round - the galvanometer from the rotating magnet. He remarks upon the - “_singular independence_” of the magnetism and the body of - the magnet which carries it. The steel behaves as if it were - isolated from its own magnetism. - - And then his thoughts suddenly widen, and he asks himself - whether the rotating earth does not generate induced - currents as it turns round its axis from west to east. In - his experiment with the twirling magnet the galvanometer - wire remained at rest; one portion of the circuit was in - motion _relatively_ to _another portion_. But in the case of - the twirling planet the galvanometer wire would necessarily - be carried along with the earth; there would be no relative - motion. What must be the consequence? Take the case of a - telegraph wire with its two terminal plates dipped into the - earth, and suppose the wire to lie in the magnetic meridian. - The ground underneath the wire is influenced, like the wire - itself, by the earth’s rotation; if a current from south to - north be generated in the wire, a similar current from south - to north would be generated in the earth under the wire; these - currents would run against the same terminal plate, and thus - neutralise each other. - - This inference appears inevitable, but his profound vision - perceived its possible invalidity. He saw that it was at least - possible that the difference of conducting power between - the earth and the wire might give one an advantage over the - other, and that thus a residual or differential current might - be obtained. He combined wires of different materials, and - caused them to act in opposition to each other, but found the - combination ineffectual. The more copious flow in the better - conductor was exactly counterbalanced by the resistance of the - worst. Still, though experiment was thus emphatic, he would - clear his mind of all discomfort by operating on the earth - itself. He went to the round lake near Kensington Palace, and - stretched 480 feet of copper wire, north and south, over the - lake, causing plates soldered to the wire at its ends to dip - into the water. The copper wire was severed at the middle, - and the severed ends connected with a galvanometer. No effect - whatever was observed. But though quiescent water gave no - effect, moving water might. He therefore worked at Waterloo - Bridge for three days, during the ebb and flow of the tide, but - without any satisfactory result. Still he urges, “Theoretically - it seems a necessary consequence, that where water is flowing - there electric currents should be formed. If a line be imagined - passing from Dover to Calais through the sea and returning - through the land, beneath the water, to Dover, it traces out - a circuit of conducting matter, one part of which, when the - water moves up or down the Channel, is cutting the magnetic - curves of the earth, whilst the other is relatively at rest.... - There is every reason to believe that currents do run in the - general direction of the circuit described, either one way or - the other, according as the passage of the waters is up or down - the Channel.” This was written before the submarine cable was - thought of, and he once informed me that actual observation - upon that cable had been found to be in accordance with his - theoretic deduction. - -[Illustration: FIG. 11.] - -It may here be apposite to discuss a fundamental question raised in -these researches. In Faraday’s mind there arose the conviction of -a connection between the induction of currents by magnets and the -magnetic lines which invisibly fill all the space in the neighbourhood -of the magnet. That relation he discovered and announced in the -following terms:-- - -[Sidenote: THE LAW OF INDUCTION.] - -“The relation which holds between the magnetic pole, the moving wire -or metal, and the direction of the current evolved--_i.e._ _the -law_ which governs the evolution of electricity by magneto-electric -induction, is very simple, though rather difficult to express. If in -Fig. 11, P N represent a horizontal wire passing by a marked [_i.e._ -‘north-seeking’] magnetic pole, so that the direction of its motion -shall coincide with the curved line proceeding from below upwards; or -if its motion parallel to itself be in a line tangential to the curved -line, but in the general direction of the arrows; or if it pass the -pole in other directions, but so as to cut the magnetic curves[39] in -the same general direction, or on the same side as they would be cut by -the wire if moving along the dotted curved line; then the current of -electricity in the wire is from P to N. If it be carried in the reverse -direction, the electric current will be from N to P. Or if the wire be -in the vertical position, figured P´ N´, and it be carried in similar -directions, coinciding with the dotted horizontal curve so far as to -cut the magnetic curves on the same side with it, the current will be -from P´ to N´.” - -[Sidenote: CUTTING THE MAGNETIC LINES.] - -When resuming the research in December, Faraday investigated the -point whether it was essential or not that the moving wire should, -in “cutting” the magnetic curves, pass into positions of greater or -lesser magnetic force; or whether, always intersecting curves of equal -magnetic intensity, the mere motion sufficed for the production of the -current. He found the latter to be true. This notion of _cutting_ the -invisible magnetic lines as the essential act necessary and sufficient -for induction was entirely original with Faraday. For long it proved -a stumbling-block to the abstract mathematicians, since there was, in -most cases, no direct or easy way in which to express the number of -magnetic lines that were cut. Neither had any convention been adopted -up to that time as to how to reckon numerically the number of magnetic -lines in any given space near a magnet. Later, in 1851, Faraday himself -gave greater precision to these ideas. He found that the current was -proportional to the velocity, when the conductor was moving in a -uniform magnetic field with a uniform motion. Also, that the quantity -of electricity thrown by induction into the circuit was directly -proportional to the “amount of curves intersected.” The following -passage, from Clerk Maxwell’s article on Faraday in the “Encyclopædia -Britannica,” admirably sums up the matter:-- - - The magnitude and originality of Faraday’s achievement may be - estimated by tracing the subsequent history of his discovery. - As might be expected, it was at once made the subject of - investigation by the whole scientific world, but some of the - most experienced physicists were unable to avoid mistakes in - stating, in what they conceived to be more scientific language - than Faraday’s, the phenomena before them. Up to the present - time the mathematicians who have rejected Faraday’s method of - stating his law as unworthy of the precision of their science, - have never succeeded in devising any essentially different - formula which shall fully express the phenomena without - introducing hypotheses about the mutual action of things which - have no physical existence, such as elements of currents which - flow out of nothing, then along a wire, and finally sink into - nothing again. - - After nearly half a century of labour of this kind, we may say - that, though the practical applications of Faraday’s discovery - have increased and are increasing in number and value every - year, no exception to the statement of these laws as given by - Faraday has been discovered, no new law has been added to them, - and Faraday’s original statement remains to this day the only - one which asserts no more than can be verified by experiment, - and the only one by which the theory of the phenomena can - be expressed in a manner which is exactly and numerically - accurate, and at the same time within the range of elementary - methods of exposition. - -In the year 1831, which witnessed this masterpiece of scientific -research, Faraday was busy in many other ways. He was still undertaking -chemical analyses and expert work for fees, as witness his letter to -Phillips on p. 62. He was also, until November, on the Council of the -Royal Society. To the “Philosophical Transactions” he contributed -a paper “On Vibrating Surfaces,” in which he solved a problem in -acoustics which had previously gone without explanation. It had long -been known that in the experiments of obtaining the patterns called -“Chladni’s figures,” by strewing powders upon vibrating plates, while -the heavier powders, such as sand, moved into the nodal lines, lighter -substances, such as lycopodium dust, collected in little circular -heaps over the parts where the vibration was most energetic. Faraday’s -explanation was that these lighter powders were caught and whirled -about in little vortices which formed themselves at spots where the -motions were of greatest amplitude. - -He also wrote a paper “On a Peculiar Class of Optical Deceptions,” -dealing with the illusions that result from the eye being shown in -successive glimpses, as between the teeth of a revolving wheel, -different views of a moving body. This research was, in effect, the -starting point of a whole line of optical toys, beginning with the -phenakistiscope or stroboscope, which developed through the zoetrope -and praxino-scope into the kinematograph and animatograph of recent -date. - -[Sidenote: LECTURES ON PHYSICAL SUBJECTS.] - -He gave four afternoon lectures at the Royal Institution and five -Friday evening discourses. These were on optical deceptions, on light -and phosphorescence, being an account of experiments recently made by -Mr. Pearsall, chemical assistant in the Institution; on oxalamide, then -recently discovered by M. Dumas; on Trevelyan’s experiments about the -production of sound by heated bodies; and on the arrangements assumed -by particles upon vibrating surfaces. - -In 1832 he gave five Friday evening discourses, four of which related -to his own researches. In August he entered upon the third series -of “Experimental Researches in Electricity,” which was devoted to -the identity of electricities derived from different sources, and on -the relation by measure of common [_i.e._ frictional] and voltaic -electricity. He did not like any doubt to hang about as to whether -the electricity obtained from magnets by induction was really the -same as that obtainable from other sources. Possibly he had in his -mind the difficulties which had arisen thirty years before over the -discoveries of Galvani and Volta, when it was so far doubted whether -the electricity in currents from piles and batteries of cells was -the same as the electricity evoked by friction, that the distinctive -and misleading name of “galvanism” was assigned to the former. -He commented on the circumstance that many philosophers--and he -included Davy by name in an explicit reference--were vainly drawing -distinctions[40] between electricities from different sources, or at -least doubting whether their identity were proven. His first point -was to consider whether “common electricity,” “animal electricity,” -and “magneto-electric currents” could, like “voltaic electricity,” -produce chemical decompositions. He began by demonstrating that an -ordinary electric discharge from a friction machine can affect a -suitably disposed galvanometer. One of his instruments of sufficient -sensitiveness was surrounded by an enclosing cage of double metal -foil and wire-work, duly connected to “earth,” so as to render it -independent of all disturbances by external electric charges in its -neighbourhood. His “earth” for this purpose consisted of a stout metal -wire connected through the pipes in the house to the metallic gas-pipes -belonging to the public gas works of London, and also with the metallic -water-pipes of London--an effectual “discharging train.” He used a -friction electric machine with a glass plate 50 inches in diameter, -and a Leyden-jar battery of fifteen jars, each having about 84 square -inches of coated glass. This battery of jars was first charged from the -machine and then discharged through a wet thread four feet long, and -through the galvanometer to earth _viâ_ the “discharging train.” Having -by this means satisfied himself that these electric discharges could -deflect a galvanometer, whether through the wet thread, a copper wire, -or through water, or rarefied air, or by connection through points in -air, he went on to the question of chemical decomposition. Dipping two -silver wires into a drop of solution of sulphate of copper, he found -that one of them became copper-plated by the electricity that was -evolved by 100 or 200 turns of the disc machine. He bleached indigo, -turned starch purple with iodine liberated from iodide of potassium, -exactly as might have been done by a “volta-electric current” from a -battery of cells. He also decomposed water, giving due recognition to -the antecedent experiments of Van Troostwyk, Pearson, and Wollaston. - -[Sidenote: IDENTITY OF ELECTRICITIES.] - -In the paper which he drew up he compares these results with others -made with electric discharges from an electric kite and with those of -the torpedo and other electric fishes. He recapitulates the properties -of magneto-electricity and the proofs now accumulating that it can -decompose water. He drew up a schedule of the different effects which -electricity can produce, and of the different sources of electricity, -showing in tabular form how far each so-called kind of electricity -had been found to produce each effect. The conclusion was that there -is no philosophical difference between the different cases; since the -phenomena produced by the different kinds of electricity differ not in -their character but only in degree. “_Electricity, whatever may be its -source, is identical in its nature._” On comparing the effects produced -by different discharges, he concludes that “if the same absolute -quantity[41] of electricity pass through the galvanometer, whatever may -be its intensity, the deflecting force upon the magnetic needle is the -same.” He was then able to go on to a quantitative comparison between -the “quantity” of electricity from different sources, and came to the -conclusion that both in magnetic deflection and in chemical force the -current of electricity given by his standard battery for eight beats of -his watch was equal to that of the friction machine evolved by thirty -revolutions; further, that “the chemical power, like the magnetic -force, is in direct proportion to the absolute quantity of electricity -which passes.” - -[Sidenote: ELECTRO-CHEMICAL WORK.] - -This series of researches was published in January, 1833. In April -of the same year he sent to the Royal Society another paper--the -fourth series--on electric conduction. It arose from the surprising -observation that, though water conducts, ice acts as a complete -non-conductor. This led to an examination of the conducting power of -fusible solids in general. He found that as a rule--excepting on the -one hand the metals, which conduct whether solid or liquid, and on the -other hand fatty bodies, which are always non-conductors--they assume -conducting power when liquefied, and lose it when congealed. Chloride -of lead, of silver, of potassium, and of sodium, and many chlorates, -nitrates, sulphates, and many other salts and fusible substances were -found to follow this rule. All the substances so found to act were -compound bodies, and capable of decomposition by the current. When -conduction ceased, decomposition ceased also. An apparent exception was -found in sulphide of silver, which, when heated, acquired conducting -powers even before it assumed the liquid state, yet decomposed in the -solid state. This led him on to study electro-chemical decompositions -more closely. Here he was following directly in the footsteps of his -master Davy, whose discovery of the decomposition of potash and soda -by the electric current had been one of the most prominent scientific -advances resulting from the invention of the voltaic cell. The fifth -series of researches, published in June, 1833, embodies the work. He -first combats the prevailing opinion that the presence of water is -necessary for electro-chemical decomposition; then analyses the views -of various philosophers--Grotthuss, Davy, De la Rive, and others--who -had discussed the question whether the decompositions are due to -attractions exercised by the two poles of the electric circuit. This he -contests in the most direct manner. Already he has reason to believe -that for a given quantity of electricity passed through the liquid -the amount of electro-chemical action is a constant quantity, and -depends in no way on the distance of the particles of the decomposable -substance from the poles. He regards the elements as progressing in two -streams in opposite directions parallel to the current, while the poles -“are merely the surfaces or doors by which the electricity enters into -or passes out of the substance suffering decomposition.” - -Amongst the laboratory notes of this time are many which were never -published in the “Experimental Researches,” or of which only brief -abstracts appeared. Some of these are of great interest. - -Here is one literally transcribed:-- - - 26 Feb. 1833. - - _Chloride Magnesium._--When solid and wire fuzed in - non-conductor--When fuzed conducted very well and was - decomposed A and P Pole much action and gas--chlorine? At N - Pole Magnesium separated and no gas. Sometimes Magnesium burnt - flying off in globules burning brilliantly. When wire at that - pole put in water or white M A [muriatic acid] matter round - it acted powerfully evolving hydrogen and forming Magnesia; - and when wire and surrounding matter heated in spirit lamp - _Magnesium_ burnt with intense light into _Magnesia_. VERY GOOD - EXPT. - -This recalls the “capital experiment” entry which Sir Humphry Davy -wrote after the account of his decomposition of caustic potash. On the -7th of April we come to a marvellous page of speculations. He has seen -that liquids, both solutions and fused salts, can be decomposed by -the current, and that at least one solid is capable of electrolysis. -But he finds that alloys and metals are not decomposed. He finds -that electrolysis is easiest for those compounds that consist of the -most diverse elements, and is led on to speculate as to the possible -constitution of those conductors that the current does not decompose. -This may involve a recasting of accepted ideas; but from such a step he -does not shrink, as the following extracts show:-- - - Metals _may_ not be compounds of elements most frequently - combined, but rather of such as are so similar to each other as - to pass out of the limit of voltaic decomposition. - - 13th April (same page). - - If voltaic decomposition of the kind I believe then review - all substances upon the new view to see if they may not be - decomposable, &c. &c. &c. - -[Sidenote: ATTRACTION BY POLES DOUBTED.] - -He has now found that the facts observed do not admit of being -explained on the supposition that the motion of the ions is due to the -attraction of the poles, and accordingly there follows the entry:-- - - (Ap. 13, 1833.) - - A single element is never attracted by a pole, _i.e._ without - attraction of other element at other pole. Hence doubt Mr. - Brande’s Expts on attraction of gases and vapours. Doubt - attraction by poles altogether. - -To this subject he returned in 1834; an intervening memoir--the -sixth--being taken up with the power of metals and solids to bring -about the combination of gaseous bodies. In the seventh series, -published in January, 1834, his first work is to explain the new -terms which he has adopted, on the advice of Whewell, to express the -facts. The so-called poles, being in his view merely doors or ways by -which the current passes, he now terms _electrodes_, distinguishing -the entrance and exit respectively as _anode_ and _cathode_,[42] -while the decomposable liquid is termed an _electrolyte_, and the -decomposing process _electrolysis_. “Finally,” he says, in a passage -(here italicised) worthy to be engraved in gold for the essential -truth it enunciates on a question of terminology, “I require a term to -express those bodies which can pass to the _electrodes_, or, as they -are usually called, the poles. Substances are frequently spoken of as -being _electronegative_, or _electropositive_, according as they go -under the supposed influence of a direct attraction to the positive or -negative pole. But these terms are much too significant for the use to -which I should have to put them; _for though the meanings are perhaps -right, they are only hypothetical, and may be wrong; and then, through -a very imperceptible but still very dangerous, because continual, -influence, they do great injury to science, by contracting and limiting -the habitual views of those engaged in pursuing it_. I propose to -distinguish such bodies by calling those _anions_ which go to the anode -of the decomposing body; and those passing to the _cathode_, _cations_; -and when I shall have occasion to speak of these together, I shall -call them _ions_.[43] Thus, the chloride of lead is an _electrolyte_, -and when _electrolyzed_ evolves the two _ions_, chlorine and lead, the -former being an _anion_ and the latter a _cation_.” In Faraday’s own -bound volume of the “Experimental Researches” he has illustrated these -terms by the sketch here reproduced. (Fig. 12.) - -Faraday’s letter to Whewell when he consulted him as to the new words -has not been preserved. He discarded, when the paper was printed, the -terms he had first used. Whewell’s replies of April 25th and May 5th, -1834, have been preserved and are printed in Todhunter’s biography -of Whewell. From the later of the two the following passage is -extracted:-- - -[Sidenote: NEW NOMENCLATURE.] - - [_Whewell to Faraday_], May 5, 1834. - - If you take _anode_ and _cathode_, I would propose for the two - elements resulting from _electrolysis_ the terms _anion_ and - _cation_, which are neuter participles signifying _that which - goes up_, and _that which goes down_; and for the two together - you might use the term _ions_.... The word is not a substantive - in Greek, but it may easily be so taken, and I am persuaded - that the brevity and simplicity of the terms you will thus have - will in a fortnight procure their universal acceptation. The - _anion_ is that which goes to the _anode_, the _cation_ is that - which goes to the _cathode_. The _th_ in the latter word arises - from the aspirate in _hodos_ (way), and therefore is not to be - introduced in cases where the second term has not an aspirate, - as _ion_ has not. - -[Illustration: FIG. 12.] - -On May 15th Faraday replied as follows:-- - - [_Faraday to Whewell._] - - I have taken your advice and the names, and use _anode_, - _cathode_, _anions_, _cations_ and _ions_; the last I shall - have but little occasion for. I had some hot objections made to - them here, and found myself very much in the condition of the - man with his Son and Ass, who tried to please everybody; but - when I held up the shield of your authority it was wonderful - to observe how the tone of objection melted away. I am quite - delighted with the facility of expression which the new terms - give me, and shall ever be your debtor for the kind assistance - you have given me. - -As though to prepare the way for a still further cutting of himself -adrift from the slavery of using terms that might be found misleading, -he added the following note:-- - - It will be well understood that I am giving no opinion - respecting the nature of the electric current now, beyond what - I have done on former occasions; and that though I speak of - the current as proceeding from the parts which are positive to - those which are negative, it is merely in accordance with the - conventional, though in some degree tacit, agreement entered - into by scientific men, that they may have a constant, certain, - and definite means of referring to the direction of the forces - of that current. - -The “former occasions” is a reference to an earlier suggestion that -a _current_ might mean anything progressive, whether a flow in one -direction or two fluids moving in opposite directions, or merely -vibrations, or, still more generally, progressive forces. He had -expressly said that what we call the electric current “may perhaps best -be conceived of as _an axis of power having contrary forces, exactly -equal in amount, in contrary directions_.” - -[Sidenote: ELECTRO-CHEMICAL LAWS.] - -He then suggests as a measurer of current the standard form of -electrolytic cell ever since known as the _voltameter_. He preferred -that kind in which water is decomposed, the quantity of electricity -which had flowed through it being measured by the quantity of the -gas or gases evolved during the operation. Before adopting this he -undertook careful experiments in which his fine manipulative skill, no -less than his chemical experience, was called into service to verify -the fact that the quantity of water decomposed was really proportionate -to the quantity of electricity which has been passed through the -instrument. Having this standard, he investigated numerous other cases -of decomposition by the current, and so arrived at a substantial basis -for the doctrine of _definite electro-chemical_ action. Speaking of -the substances into which electrolytes are divided by the current, -and which he had called ions, he says: “They are combining bodies; -are directly associated with the fundamental parts of the doctrine -of chemical affinity; and have each a definite proportion, in which -they are always evolved during electrolytic action.... I have proposed -to call the numbers representing the proportions in which they are -evolved _electro-chemical equivalents_. Thus hydrogen, oxygen, -chlorine, iodine, lead, tin are _ions_; the three former are _anions_, -the two metals _cations_, and 1, 8, 36, 125, 104, 58, are their -_electro-chemical equivalents_ nearly.” - -This fundamental law being set upon an impregnable basis of facts, -he goes on to speculate upon the _absolute quantity_ of electricity -or electric power belonging to different bodies; a notion which only -within the last few years has found general acceptance. - -In developing this theory he uses the following language:-- - - According to it [_i.e._ this theory], the equivalent weights of - bodies are simply those quantities of them which contain equal - quantities of electricity, or have naturally equal electric - powers; it being the ELECTRICITY which _determines_ the - equivalent number, _because_ it determines the combining force. - Or, if we adopt the atomic theory or phraseology, then the - atoms of bodies which are equivalents to each other in their - ordinary chemical action, have equal quantities of electricity - naturally associated with them. But I must confess I am jealous - of the term _atom_.... - -Here we find the modern doctrine of _electrons_ or unitary atomic -charges, clearly formulated in 1834. In the course of this speculation -he remarks that “if the electrical power which holds the elements of -a grain of water in combination, or which makes a grain of oxygen or -hydrogen in the right proportions unite into water when they are made -to combine, could be thrown into the condition of _a current_, it -would exactly equal the current required for the separation of that -grain of water into its elements again.” And all this years before -there was any doctrine of the conservation of energy to guide the mind -of the philosopher! The passage just cited contains the germs of the -thermodynamic theory of electromotive forces worked out a dozen years -later by Sir William Thomson (now Lord Kelvin), by which theory we can -predict the electromotive forces of any given chemical combination from -a knowledge of the heat evolved by a given mass of the product in the -act of combining. - -[Sidenote: ANOTHER UNSUCCESSFUL QUEST.] - -The eighth series of the researches, which was read in June, 1834, -deals chiefly with voltaic cells and batteries of cells. He is now -applying to the operations inside the primary cell the electrochemical -principles learned by the study of electrolysis in secondary cells. -His thoughts have been incessantly playing around the problem of -electrolytic conduction. He was convinced that the forces which shear -the anions from combination with the cations and transfer them in -opposite directions must be inherent before the circuit is completed, -and therefore before any actual transfer or movement takes place. “It -seems to me impossible,” he says, “to resist the idea that it [the -“transfer,” or “what is called the voltaic current”] must be preceded -by a _state of tension_ in the fluid. I have sought carefully for -indications of a state of tension in the electrolytic conductor; and -conceiving that it might produce something like structure, either -before or during its discharge, I endeavoured to make this evident by -polarised light.” He used a solution of sulphate of soda, but without -the slightest trace of optical action in any direction of the ray. He -repeated the experiment, using a solid electrolyte, borate of lead, in -its non-conducting state, but equally without result. - -During the time of these electrochemical researches in 1833 and 1834, -Faraday’s activities for the Royal Institution were undiminished. In -1833 he gave seven Friday discourses, three of them on the researches -in hand, one on Wheatstone’s investigation of the velocity of the -electric spark, and one on the practical prevention of dry rot in -timber, which was afterwards republished as a pamphlet, and ran to -two editions. In 1834 he gave four Friday discourses; two on his -electrochemical researches, one on Ericsson’s heat-engine, and the -other on caoutchouc. - -The ninth series of electrical researches occupied the autumn of 1834. -In it he returns to the study of the magnetic and inductive actions -of the current, investigating the self-induced spark at the break -of the circuit, to which his attention had been directed by Mr. W. -Jenkin. Several points in this research are little known even now to -electricians, the laboratory notes being much more detailed than the -published paper. He describes an exceedingly neat high-speed break -for producing rapid interruptions, using for that purpose stationary -ripples on the surface of a pool of mercury. In a wonderful day’s work -on 13th November, filling thirty-four pages of the laboratory book, -illustrated with numerous unpublished sketches, he tracks out the -properties of self-induction. He proves that the spark (on breaking -circuit) from a wire coiled up in a helix is far brighter than that -from an identical wire laid out straight. He finds that a non-inductive -and, therefore, sparkless coil can be made by winding the wire in two -opposite helices. “Thus the whole [inductive] effect of the length -of wire was neutralised by the reciprocal and contrary action of the -two halves which constituted the helices in contrary directions.” The -next day he writes: “These effects show that every part of an electric -circuit is acting by induction on the neighbouring parts of the same -current, even in the _same wire_ and the _same part_ of the wire.” - -[Sidenote: EFFECTS OF SELF-INDUCTION.] - -On 22nd November he is trying another set of experiments, also never -fully published. They relate to the diminution of self-induction of a -straight conductor by dividing it into several parallel strands at a -small distance apart from one another. The note in the laboratory book -runs thus:-- - - Copper wire 1/23 of inch in diameter. Six lengths of five feet - each, soldered at ends to piece of copper plate so as form - terminations, and these amalgamated. When this bundle was used - to connect the electro-motor it gave but very feeble spark on - breaking contact, but the spark was sensibly better when the - wires are held together so as to act laterally than when they - were opened out from each other, thus showing lateral action. - - Made a larger bundle of the same fine copper wire. There were - 20 lengths of 18 feet 2 inches each and the thick terminal - pieces of copper wire 6 inches long and ⅓ of inch thick. - -[Illustration: FIG. 13.] - -This bundle he compared with a length of 19 feet 6 inches of a single -copper wire ⅕ inch in diameter, having about equal sectional area. The -latter gave decidedly the largest sparks on breaking circuit. - -Faraday did not see fit at this time to accept the idea, suggested -indeed by himself in 1831, that these effects of self-induction were -the analogue of momentum or inertia. That explanation he set aside -on finding that the same wire when coiled had greater self-inductive -action than when straight. Had he at that time grasped this analogy, he -would have seen that the very property which gives rise to the spark -at break of circuit also retards the rapid growth of a current; and -then the experiment described above would have shown him that Sir W. -Snow Harris was right in preferring flat copper ribbon to a round wire -of equivalent section as a material for lightning conductors. He was, -however, disappointed to find so small a difference between round wires -and parallel strands. The memoir as published contains an exceedingly -interesting conclusion:-- - - Notwithstanding that the effects appear only at the making - and breaking of contact (the current, remaining unaffected, - seemingly, in the interval,) I cannot resist the impression - that there is some connected and correspondent effect produced - by this lateral action of the elements of the electric stream - during the time of its continuance. An action of this kind, - in fact, is evident in the magnetic relations of the parts - of the current. But admitting (as we may do for the moment) - the magnetic forces to constitute the power which produces - such striking and different results at the commencement and - termination of a current, still there appears to be a link in - the chain of effects--a wheel in the physical mechanism of the - action, as yet unrecognised. - -The tenth series of researches, on the voltaic battery, though -completed in October, 1834, was not published till June, 1835. - -[Sidenote: ACTION IN A MEDIUM.] - -The next research, begun in the autumn of 1835, after a lull of -about eight months, lasted over two years. It was not completed till -December, 1837. This investigation took Faraday away from magnetic -and electrochemical matters to the old subject of statical electric -charges, a subject hitherto untouched in his researches. But he had -long brooded over the question as to the nature of an electric charge. -Over and over again, as he had watched the inductive effect of electric -currents acting from wire to wire, his mind turned to the old problem -of the inductive influence--discovered eighty years before, by John -Canton--exerted, apparently at a distance, by electric charges. He -had learned to distrust action at a distance, and now the time was -ripe for a searching inquiry as to whether electric _influence_, or -induction[44] as it was then called, was also an action propagated by -contiguous actions in the intervening medium. - -Faraday had done no special electric work during the first nine months -of 1835. He had worked at a chemical investigation of fluorine through -the spring, and in July took a hurried tour in Switzerland, and -returned to work at fluorine. Not till November 3rd does he turn to the -subject over which he had been brooding. On that date, intercalated -between notes of his chemical studies, filling a dozen pages of the -laboratory book, are a magnificent series of speculations as to the -nature of charges, and on the part played by the electric--or, as we -should now say, the dielectric--medium. They begin thus:-- - -“Have been thinking much lately of the relation of common and -voltaic electricity, of induction by the former and decomposition by -the latter, and am quite convinced that there must be the closest -connection. Will be first needful to make out the true character”--note -the phrase--“of ordinary electrical phenomena.” The following notes -are for experiment and observation. - -“Does common electricity reside upon the surface of a conductor or upon -the surface of the [di-]electric in contact with it?” - -He goes on to consider the state of a dielectric substance, such as -glass, when situated between a positively charged and a negatively -charged surface, as in a charged Leyden jar, and argues from analogy -thus:-- - -“Hence the state of the plate [of glass] under induction is the same -as the state of a magnet, and if split or broken would present new -P[ositive] and N[egative] surfaces before not at all evident.” This -speculation was later verified by Matteucci. - -“Probable that phenomena of induction prove more decidedly than -anything else that the electricity is in the [di-]electric not in the -conductor.” - -He still worked for a week or two on fluorine, interposing some -experiments on the temperature-limit of magnetisation, but on December -4th decides not to go on with fluorine at present. Then, beginning on -December 5th, there follow twenty-nine pages of the laboratory diary, -illustrated with sketches. He had borrowed from a Mr. Kipp a large -deep copper pan thirty-five inches in diameter, and he set to work -electrifying it and exploring the distribution of the charges, inside -and out, and the inductive effect on objects placed within. Everywhere -he is mentally comparing the distribution of the effects with that of -the flow of currents in an electrolyte. Before many days he writes:-- - -[Sidenote: PREGNANT SUGGESTIONS.] - -“It appears to me at present that _ordinary_ and _electrolytic_ -induction are identical in their first nature, but that the latter is -followed by an effect which cannot but from the nature and state of -the substances take place with the former.” Then comes this pregnant -suggestion:-- - -“Try induction through a solid crystalline body as to the consequent -action on polarized light.” - -By the end of a week he had begun to suspect that his magnet analogy -went farther than he was at first prepared to hold. The action of a -magnet was along curved lines of force. So he asks:-- - -“Can induction through air take place in curves or round a corner--can -probably be found experimentally--if so not a radiating effect.” - -After ten days more he has made another step. - -“Electricity appears to exist only in _polarity_ as in air, glass, -electrolytes, etc. Now metals, being conductors, cannot take up that -polar state of their own power, or rather retain it, and hence probably -cannot retain developed electric forces. - - * * * * * - -“Metals, however, probably hold it for a moment, as other things do for -a longer time; an end coming at last to all.” - -This, it will be observed, is nothing more or less than Clerk Maxwell’s -theory of conduction as being the breaking down of an electrostatic -strain. - -In January, 1836, followed the famous experiment of building a -twelve-foot cube, which when electrified exteriorly to the utmost -extent, showed inside no trace of electric forces. The account in the -unpublished MS. of the laboratory book is, as is the case with so -many of these middle-period researches, much fuller than the published -_résumé_ of them in the “Experimental Researches.” All through 1836 -he was still at work. Even when on a holiday in the Isle of Wight, in -August, he took his notebook with him, and writes:-- - -“After much consideration (here at Ryde) of the manner in which the -electric forces are arranged in the various phenomena generally, I have -come to certain conclusions which I will endeavour to note down without -committing myself to any opinion as to the cause of electricity, _i.e._ -as to the nature of the power. If electricity exist independently of -matter, then I think that the hypothesis of one fluid will not stand -against that of two fluids. There are, I think, evidently, what I may -call two elements of power of equal force and acting towards each -other. These may conventionally be represented by oxygen and hydrogen, -which represent them in the voltaic battery. But these powers may be -distinguished only _by direction_, and may be no more separate than the -north and south forces in the elements of a magnetic needle. They may -be the polar points of the forces originally placed in the particles of -matter; and the description of the current as an axis of power which I -have formerly given suggests some similar general impression for the -forces of quiescent electricity. Law of electric tension might do, and -though I shall use the terms positive and negative, by them I merely -mean the termini of such lines.” - -Right on until November 30th, 1837, this research was continued. The -summary of this and the succeeding researches of 1838 on the same -subject, drawn up by Professor Tyndall,[45] is at once so masterly -and so impartial that it cannot be bettered. It is therefore here -transcribed without alteration. - -[Sidenote: ACTION AT A DISTANCE UNTHINKABLE.] - - His first great paper on frictional electricity was sent to - the Royal Society on November 30, 1837. We here find him face - to face with an idea which beset his mind throughout his - whole subsequent life--the idea of _action at a distance_. It - perplexed and bewildered him. In his attempts to get rid of - this perplexity he was often unconsciously rebelling against - the limitations of the intellect itself. He loved to quote - Newton upon this point: over and over again he introduces his - memorable words, “That gravity should be innate, inherent, and - essential to matter, so that one body may act upon another - at a distance through a _vacuum_ and without the mediation - of anything else, by and through which this action and force - may be conveyed from one to another, is to me so great an - absurdity, that I believe no man who has in philosophical - matters a competent faculty of thinking can ever fall into it. - Gravity must be caused by an agent acting constantly according - to certain laws; but whether this agent be material or - immaterial I have left to the consideration of my readers.”[46] - - Faraday does not see the same difficulty in his contiguous - particles. And yet by transferring the conception from masses - to particles we simply lessen size and distance, but we do not - alter the quality of the conception. Whatever difficulty the - mind experiences in conceiving of action at sensible distances, - besets it also when it attempts to conceive of action at - insensible distances. Still the investigation of the point - whether electric and magnetic effects were wrought out through - the intervention of contiguous particles or not, had a physical - interest altogether apart from the metaphysical difficulty. - Faraday grapples with the subject experimentally. By simple - intuition he sees that action at a distance must be exerted in - straight lines. Gravity, he knows, will not turn a corner, but - exerts its pull along a right line; hence his aim and effort to - ascertain whether electric action ever takes place in curved - lines. This once proved, it would follow that the action is - carried on _by means of a medium_ surrounding the electrified - bodies. His experiments in 1837 reduced, in his opinion, this - point to demonstration. He then found that he could electrify - by induction an insulated sphere placed completely in the - shadow of a body which screened it from direct action. He - pictured the lines of electric force bending round the edges - of the screen, and reuniting on the other side of it; and he - proved that in many cases the augmentation of the distance - between his insulated sphere and the inducing body, instead of - lessening, increased the charge of the sphere. This he ascribed - to the coalescence of the lines of electric force at some - distance behind the screen. - - [Sidenote: SPECIFIC INDUCTIVE CAPACITY.] - - Faraday’s theoretic views on this subject have not received - general acceptance, but they drove him to experiment, and - experiment with him was always prolific of results. By suitable - arrangements he places a metallic sphere in the middle of a - large hollow sphere, leaving a space of something more than - half an inch between them. The interior sphere was insulated, - the external one uninsulated. To the former he communicated a - definite charge of electricity. It acted by induction upon the - concave surface of the latter, and he examined how this act of - induction was affected by placing insulators of various kinds - between the two spheres. He tried gases, liquids, and solids, - but the solids alone gave him positive results. He constructed - two instruments of the foregoing description, equal in size - and similar in form. The interior sphere of each communicated - with the external air by a brass stem ending in a knob. The - apparatus was virtually a Leyden jar, the two coatings of which - were the two spheres, with a thick and variable insulator - between them. The amount of charge in each jar was determined - by bringing a proof-plane into contact with its knob, and - measuring by a torsion balance the charge taken away. He first - charged one of his instruments, and then dividing the charge - with the other, found that when air intervened in both cases, - the charge was equally divided. But when shell-lac, sulphur, - or spermaceti was interposed between the two spheres of one - jar, while air occupied this interval in the other, then he - found that the instrument occupied by the “solid dielectric” - took _more than half_ the original charge. A portion of the - charge was absorbed in the dielectric itself. The electricity - took time to penetrate the dielectric. Immediately after the - discharge of the apparatus no trace of electricity was found - upon its knob. But after a time electricity was found there, - the charge having gradually returned from the dielectric in - which it had been lodged. Different insulators possess this - power of permitting the charge to enter them in different - degrees. Faraday figured their particles as polarised, and - he concluded that the force of induction is propagated from - particle to particle of the dielectric from the inner sphere - to the outer one. This power of propagation possessed by - insulators he calls their “_Specific Inductive Capacity_.” - - [Illustration: FIG. 14.] - - Faraday visualises with the utmost clearness the state of his - contiguous particles; one after another they become charged, - each succeeding particle depending for its charge upon its - predecessor. And now he seeks to break down the wall of - partition between conductors and insulators. “Can we not,” he - says, “by a gradual chain of association carry up discharge - from its occurrence in air through spermaceti and water to - solutions, and then on to chlorides, oxides, and metals, - without any essential change in its character?” Even copper, he - urges, offers a resistance to the transmission of electricity. - The action of its particles differs from those of an insulator - only in degree. They are charged like the particles of the - insulator, but they discharge with greater ease and rapidity; - and this rapidity of molecular discharge is what we call - conduction. Conduction, then, is always preceded by atomic - induction; and when through some quality of the body, which - Faraday does not define, the atomic discharge is rendered slow - and difficult, conduction passes into insulation. - - Though they are often obscure, a fine vein of philosophic - thought runs through these investigations. The mind of the - philosopher dwells amid those agencies which underlie the - visible phenomena of induction and conduction; and he tries by - the strong light of his imagination to see the very molecules - of his dielectrics. It would, however, be easy to criticise - these researches, easy to show the looseness, and sometimes - the inaccuracy, of the phraseology employed; but this critical - spirit will get little good out of Faraday. Rather let those - who ponder his works seek to realise the object he set before - him, not permitting his occasional vagueness to interfere - with their appreciation of his speculations. We may see the - ripples, and eddies, and vortices of a flowing stream, without - being able to resolve all these motions into their constituent - elements; and so it sometimes strikes me that Faraday clearly - saw the play of fluids and ethers and atoms, though his - previous training did not enable him to resolve what he saw - into its constituents, or describe it in a manner satisfactory - to a mind versed in mechanics. And then again occur, I - confess, dark sayings, difficult to be understood, which - disturb my confidence in this conclusion. It must, however, - always be remembered that he works at the very boundaries of - our knowledge, and that his mind habitually dwells in the - “boundless contiguity of shade” by which that knowledge is - surrounded. - - [Sidenote: CABLE RETARDATION PREDICTED.] - - In the researches now under review the ratio of speculation and - reasoning to experiment is far higher than in any of Faraday’s - previous works. Amid much that is entangled and dark we have - flashes of wondrous insight and utterances which seem less - the product of reasoning than of revelation. I will confine - myself here to one example of this divining power:--By his - most ingenious device of a rapidly rotating mirror, Wheatstone - had proved that electricity required time to pass through - a wire, the current reaching the middle of the wire later - than its two ends. “If,” says Faraday, “the two ends of the - wire in Professor Wheatstone’s experiments were immediately - connected with two large insulated metallic surfaces exposed - to the air, so that the primary act of induction, after - making the contact for discharge, might be in part removed - from the internal portion of the wire at the first instance, - and disposed for the moment on its surface jointly with the - air and surrounding conductors, then I venture to anticipate - that the middle spark would be more retarded than before. And - if those two plates were the inner and outer coatings of a - large jar or Leyden battery, then the retardation of the spark - would be much greater.” This was only a _prediction_, for the - experiment was not made. Sixteen years subsequently, however, - the proper conditions came into play, and Faraday was able to - show that the observations of Werner Siemens and Latimer Clark - on subterraneous and submarine wires were illustrations, on a - grand scale, of the principle which he had enunciated in 1838. - The wires and the surrounding water act as a Leyden jar, and - the retardation of the current predicted by Faraday manifests - itself in every message sent by such cables. - - The meaning of Faraday in these memoirs on induction and - conduction is, as I have said, by no means always clear; - and the difficulty will be most felt by those who are best - trained in ordinary theoretic conceptions. He does not know - the reader’s needs, and he therefore does not meet them. For - instance, he speaks over and over again of the impossibility - of charging a body with one electricity, though the - impossibility is by no means evident. The key to the difficulty - is this. He looks upon every insulated conductor as the inner - coating of a Leyden jar. An insulated sphere in the middle of - a room is to his mind such a coating; the walls are the outer - coating, while the air between both is the insulator, across - which the charge acts by induction. Without this reaction of - the walls upon the sphere, you could no more, according to - Faraday, charge it with electricity than you could charge a - Leyden jar, if its outer coating were removed. Distance with - him is immaterial. His strength as a generaliser enables him - to dissolve the idea of magnitude; and if you abolish the - walls of the room--even the earth itself--he would make the - sun and planets the outer coating of his jar. I dare not - contend that Faraday in these memoirs made all these theoretic - positions good. But a pure vein of philosophy runs through - these writings; while his experiments and reasonings on the - forms and phenomena of electrical discharge are of imperishable - importance. - -In another part of the twelfth memoir, not included in the above -summary, Faraday deals with the disruptive discharge, and with the -nature of the spark under varying conditions. This is continued on into -the thirteenth memoir, read February, 1838, and is extended to the -cases of “brush” and “glow” discharges. He discovered the existence of -the very remarkable phenomenon of the “dark” discharge near the cathode -in rarefied air. He sought to correlate _all_ the various forms of -discharge, as showing the essential nature of an electric current. “If -a ball be electrified positively,” he says, “in the middle of a room, -and be then moved in any direction, effects will be produced, as if -a _current_ in the same direction (to use the conventional mode of -expression) had existed.” This is the theory of convection currents -later adopted by Maxwell, and verified by experiment by Rowland in 1876. - -[Sidenote: COINAGE OF NEW WORDS.] - -In the course of this research on induction, Faraday had, as we have -seen, been compelled to adopt new ideas, and therefore to adopt new -names to denote them. The term _dielectric_ for the medium in or across -which the electric forces operate was one of these. As in previous -cases, he consulted with his friends as to suitable terms. In this -instance the following letter from Whewell explains itself. The letter -to which it is a reply has not been preserved, but the reference to -Faraday’s objection to the word _current_ may be elucidated by a -comparison with what Faraday wrote in criticism of that word on pages -146 and 212. - - [_Rev. W. Whewell to M. Faraday._] - - TRIN. COLL., CAMBRIDGE, _Oct. 14, 1837_. - - MY DEAR SIR,--I am always glad to hear of the progress of - your researches, and never the less so because they require - the fabrication of a new word or two. Such a coinage has - always taken place at the great epochs of discovery; like the - medals that are struck at the beginning of a new reign:--or - rather like the change of currency produced by the accession - of a new sovereign; for their value and influence consists in - their coming into common circulation. I am not sure that I - understand the views which you are at present bringing into - shape sufficiently well to suggest any such terms as you think - you want. I think that if I could have a quarter of an hour’s - talk with you I should probably be able to construct terms - that would record your new notions, so far as I could be made - to understand them better than I can by means of letters: for - it is difficult without question and discussion to catch the - precise kind of relation which you want to express. However, - by way of beginning such a discussion, I would ask you whether - you want abstract terms to denote the different and related - conditions of the body which exercises and the body which - suffers induction? For though both are active and both passive - it may still be convenient to suppose a certain ascendancy on - one side. If so would two such words as _inductricity_ and - _inducteity_ answer your purpose? They are not very monstrous - in their form; and are sufficiently distinct. And if you - want the corresponding adjectives you may call the one the - _inductric_, and the other the _inducteous_ body. This last - word is rather a startling one; but if such relations are to - be expressed, terminations are a good artifice, as we see in - chemistry: and I have no doubt if you give the world facts - and laws which are better expressed with than without such - solecisms, they will soon accommodate to the phrases, as they - have often done to worse ones. But I am rather in the dark - as to whether this is the kind of relation which you want to - indicate. If not, the attempt may perhaps serve to shew you - where my dulness lies. I do not see my way any better as to the - other terms, for I do not catch your objection to _current_, - which appears to me to be capable of jogging on very well - from _cathode_ to _anode_, or vice versa. As for positive and - negative, I do not see why _cathodic_ and _anodic_ should not - be used, if they will do the service you want of them. - - I expect to be in London at the end of the month, and could - probably see you for half an hour on the 1st of November, say - at 10, 11, or 12. But in the mean time I shall be glad to hear - from you whether you can make anything of such conundrums as I - have mentioned, and am always yours very truly, - - W. WHEWELL. - - M. FARADAY Esq^{re.} - Royal Institution. - - -[Sidenote: LATERAL ACTIONS OF CURRENT.] - -The concluding part of the thirteenth memoir, in which these new -terms are used, is an exceedingly striking speculation on the lateral -or transverse effects of the current. In calling special attention -to them, he says: “I refer of course to the magnetic action and its -relations; but though this is the only recognised lateral action of -the current, there is great reason for believing that others exist and -would by their discovery reward a close search for them.” He seems to -have had an instinctive perception of something that eluded his grasp. -Not until after Maxwell had given mathematical form to Faraday’s own -suggestions was this vision to be realised. He is dimly aware that -there appears to be a lateral tension or repulsion possessed by the -lines of electric inductive action; and onward runs his thought in free -speculation:-- - - When current or discharge occurs between two bodies, previously - under inductrical relations to each other, the lines of - inductive force will weaken and fade away, and, as their - lateral repulsive tension diminishes, will contract and - ultimately disappear in the line of discharge. May not this be - an effect identical with the attractions of similar currents? - _i.e._ may not the passage of static electricity into current - electricity, and that of the lateral tension of the lines of - the inductive force into the lateral attraction of lines of - similar discharge, have the same relation and dependences, and - run parallel to each other? - -Series fourteen of the memoirs is on the nature of the electric -force and on the relation of the electric and magnetic forces, and -comprises an inconclusive inquiry as to a possible relation between -specific inductive capacity and axes of crystallisation in crystalline -dielectrics--a relation later assumed as true by Maxwell even before -it was demonstrated by Von Boltzmann. In this memoir, too, occurs a -description of a simple but effective induction balance. Then he asks -what happens to insulating substances, such as air or sulphur, when -they are put in a place where the magnetic forces are varying; they -ought, he thinks, to undergo some state or condition corresponding -to the state that causes currents in metals and conductors, and, -further, that state ought to be one of _tension_. “I have,” he says, -“by rotating non-conducting bodies near magnetic poles, and poles near -them, and also by causing powerful electric currents to be suddenly -formed and to cease around and about insulators in various directions, -endeavoured to make some such state sensible, but have not succeeded.” -In short, he was looking for direct evidence of the existence of what -Maxwell called “displacement currents”--evidence which was later found -independently by the author and by Röntgen. And, again, there rises in -his mind a perception of that _electrotonic state_ which had haunted -his earlier researches as a something imposed upon the surrounding -medium during the growth or dying of an electric current. - -[Sidenote: INCESSANT ACTIVITIES.] - -In these years (1835–1838) Faraday was still indefatigable in his -lecture duties. In 1835 he gave four Friday discourses, and in May -and June eight afternoon lectures at the Royal Institution on the -metals; also a course of fourteen lectures on electricity to the -medical students at St. George’s Hospital. In 1836 he published -in the _Philosophical Magazine_ a paper on the magnetism of the -metals--notable as containing the still unverified speculation that all -metals would become magnetic in the same way as iron if only cooled to -a sufficiently low temperature--and three other papers, including one -on the “passive” state of iron. He gave four Friday discourses and six -afternoon lectures on heat. In 1837 also four Friday night discourses -and six afternoon lectures were delivered. In 1838 three Friday -discourses and eight afternoon lectures on electricity, ending in June -with a distinct enunciation of the doctrine of the transformations of -“force” (_i.e._ energy) and its indestructibility, afforded evidence of -his industry in this respect. At the same time he was giving scientific -advice to the authorities of Trinity House as to their lighthouses. - -The laboratory notebook for March to August, 1838, shows a long -research, occupying nearly 100 folio pages, on the relation of specific -inductive capacity to crystalline structure. This is followed by some -experiments upon an electric eel, at the Royal Adelaide Gallery, -with some unpublished sketches of the distribution in the water of -the currents it emits. He proved, with great satisfaction, that the -currents it gave were capable of producing magnetic effects, sparks, -and chemical decomposition. These observations were embodied in the -fifteenth series of memoirs. - -One entry in the laboratory book, of date April 5th, 1838, is of great -interest, as showing how his mind ever recurred to the possibility of -finding a connection between optical and electric phenomena: “Must -try polarized light across a crystalline dielectric under charge. Good -reasons perhaps now evident why a non-crystalline dielectric should -have no effect.” - -Faraday was now feeling greatly the strain of all these years of work, -and in 1839 did little research until the autumn. Then he returned to -the question of the origin of the electromotive force of the voltaic -cell, and by the end of the year completed two long papers on this -vexed question; they formed the sixteenth and seventeenth series, and -conclude the memoirs of this second period. - -[Sidenote: THE CONTACT THEORY OF ELECTRICITY.] - -In the eighth series, completed in April, 1834, on the “Electricity of -the Voltaic Pile,” Faraday had dealt with the question--at that time a -topic of excited controversy--of the origin of the electromotive force -in a cell, Volta, who knew nothing of the chemical actions, ascribed -it to the contact of dissimilar metals, whilst Wollaston, Becquerel, -and De la Rive considered it the result of chemical actions. The -controversy has long ceased to interest the scientific world; for, -with the recognition of the principle of the conservation of energy, -it became evident that mere contact cannot provide a continuing supply -of energy. It would now be altogether dead but for the survival of a -belief in the contact theory on the part of one of the most honoured -veterans in science. But in the years 1834 to 1840 it was of absorbing -interest. Faraday’s work quietly removed the props which supported the -older theory, and it crumbled away. He found that the chemical and -electrical effects in the cell were proportional one to the other, and -inseparable. He discovered a way of making a cell without any metallic -contacts. He showed that without chemical action there was no current -produced. But his results were ignored for the time. After six years -Faraday reopened the question. Again the admirable summary of Professor -Tyndall is drawn upon for the following account:-- - - The memoir on the “Electricity of the Voltaic Pile,” published - in 1834, appears to have produced but little impression upon - the supporters of the contact theory. These indeed were men - of too great intellectual weight and insight lightly to take - up, or lightly to abandon, a theory. Faraday therefore resumed - the attack in two papers communicated to the Royal Society on - February 6 and March 19, 1840. In these papers he hampered - his antagonists by a crowd of adverse experiments. He hung - difficulty after difficulty about the neck of the contact - theory, until in its efforts to escape from his assaults it so - changed its character as to become a thing totally different - from the theory proposed by Volta. The more persistently it was - defended, however, the more clearly did it show itself to be - a congeries of devices, bearing the stamp of dialectic skill - rather than that of natural truth. - - In conclusion, Faraday brought to bear upon it an argument - which, had its full weight and purport been understood at - the time, would have instantly decided the controversy. “The - contact theory,” he urged, “assumes that a force which is able - to overcome powerful resistance, as for instance that of the - conductors, good or bad, through which the current passes, - and that again of the electrolytic action where bodies are - decomposed by it, _can arise out of nothing_; that without - any change in the acting matter, or the consumption of any - generating force, a current shall be produced which shall go - on for ever against a constant resistance, or only be stopped, - as in the voltaic trough, by the ruins which its exertion has - heaped up in its own course. This would indeed be _a creation - of power_, and is like no other force in nature. We have many - processes by which the _form_ of the power may be so changed, - that an apparent _conversion_ of one into the other takes - place. So we can change chemical force into the electric - current, or the current into chemical force. The beautiful - experiments of Seebeck and Peltier show the convertibility of - heat and electricity; and others by Oersted and myself show - the convertibility of electricity and magnetism. _But in no - case, not even in those of the gymnotus and torpedo, is there a - pure creation or a production of power without a corresponding - exhaustion of something to supply it._” - -In 1839 Faraday gave five Friday discourses and a course of eight -afternoon lectures on the non-metallic elements. In 1840 he gave -three Friday discourses and seven lectures on chemical affinity. But -in the summer came the serious breakdown alluded to on page 75. He -did no experimental work after September 14th, nor indeed for nearly -two years. Even then it was only a temporary return to research to -investigate the source of the electrification produced by steam in the -remarkable experiments of Mr. (afterwards Lord) Armstrong. He proved it -to be due to friction. This done, he continued to rest from research -until the middle of 1844, though he lectured a little for the Royal -Institution. In 1841 he gave the juvenile lectures. In 1842 he gave -two Friday discourses, one of them being on the lateral discharge in -lightning-rods. He also gave the Christmas lectures on electricity. - -[Sidenote: END OF SECOND ACTIVE PERIOD.] - -In 1843 he gave three Friday discourses, one of which was on the -electricity generated by a jet of steam; and repeated the eight -afternoon lectures he had given in 1838. In 1844 he gave eight lectures -on heat and two Friday discourses. He also resumed research on the -condensation of gases, and vainly tried to liquefy oxygen and hydrogen, -though he succeeded with ammonia and nitrous oxide. - -During these years of rest he also did a little work for Trinity House, -chiefly concerning lighthouses and their ventilation. - - - - -CHAPTER V. - -SCIENTIFIC RESEARCHES: THIRD PERIOD. - - -Throughout the fruitful ten years of Faraday’s middle period two -magistral ideas had slowly grown up in his mind, and as he let his -thought play about the objects of his daily activities, these ideas -possessed and dominated him as no newly suggested idea could have done. -They were the correlation and inter-convertibility of the forces of -nature, and the optical relations of magnetism and electricity. - -During the period of enforced rest, from 1839 to 1844, these ideas had -been ever with him. His was a mind which during times of quiet brooding -did not cease to advance. In silence his thoughts arranged themselves -in readiness for the next period of activity, and his work, when it -began again, was all the more fruitful for the antecedent period of -cogitation. - -[Sidenote: OPTICAL ANALYSIS.] - -On August 30th, 1845, Faraday for the sixth time set to work in his -laboratory to search for the connection between light and electricity -for which he had so often looked, and about which he had so boldly -speculated. He began by looking for some effect to be produced on -polarised light by passing it through a liquid which was undergoing -electrolysis. What effect precisely he expected to observe is unknown. -Doubtless he had an open mind to perceive effects of any kind had such -occurred. Earlier in the century the phenomena of polarised light had -been worked out in great detail, through a host of beautiful phenomena, -by Arago, Biot, Brewster, and others; and their discoveries had shown -that this agent is capable of revealing in transparent substances -details of structure which otherwise would be quite invisible. Placed -between two Nicol prisms or two slices of tourmaline, to serve -respectively as “polariser” and “analyser,” thin sheets of transparent -crystal--selenite or mica--were made to reveal the fact that they -possessed an axis of maximum elasticity. For when the analyser and -polariser were set in the “crossed” position, where the one would cut -off all the luminous vibrations that the other would transmit, no light -would be visible to the observer, unless in the intervening space there -were interposed some substance endowed with one of two properties, -either that of resolving some part of the vibrations into an oblique -direction or else that of rotating the plane of the vibrations to right -or to left. If either of these things is done, light appears through -the analyser. It is thus that structure is observed in horn and in -starch grains. It is thus that the strains in a piece of compressed -glass are made visible. It is thus that crystalline structures -generally can be studied. It is thus that the discovery was made of the -substances which possess the strange property of twisting or rotating -the plane of polarisation of light--namely, quartz crystal, solutions -of sugar and of certain alkaloids, and certain other liquids, such -as turpentine. Such was the agent which Faraday proposed to employ to -detect whether electric forces impress any quality resembling that of -_structure_ upon transparent materials. - -The notes begin with the words:-- - -“I have had a glass trough made 24 inches long, 1 inch wide and -about 1½ deep, in which to decompose electrolites and, whilst under -decomposition, along which I could pass a ray of light in different -conditions and afterwards examine it.” - -He put into this trough two platinum electrodes and a solution of -sulphate of soda, but could find no effects. Eight pages of the -notebook are filled with details all leading to negative results. For -ten days he worked at these experiments with liquid electrolytes. -The substances used were distilled water, solution of sugar, dilute -sulphuric acid, solution of sulphate of soda (using platinum -electrodes), and solution of sulphate of copper (using copper -electrodes). The current was sent along the ray, and perpendicular -to it in two directions at right angles with each other. The ray -was made to rotate, by altering the position of the polariser (in -this case a black-glass mirror at the proper angle), so that the -plane of polarisation might be varied. The current was used as a -continuous current, as a rapidly intermitting current, and as a rapidly -alternating induction current; _but in no case was any trace of action -perceived_. - -[Sidenote: A DIFFICULT RESEARCH.] - -Then he turned to solid dielectrics to see if under electric strain -they would yield any optical effect. He had indeed so far back as -1838 tried the experiment of coating two opposite faces of a glass -cube with metal foil plates that were then electrified by a powerful -electric machine. But the experiment had no result. This experiment -he now repeats with a score of elaborate variations, trying both -crystalline and non-crystalline dielectrics. Rock-crystal, Iceland -spar, flint glass, heavy-glass, turpentine, and air, had a beam of -polarised light passed through them, and at the same time “lines of -electrostatic tension” were, by means of the coatings, Leyden jars, -and the electric machine, directed across these bodies, both parallel -to the polarised ray and across it, both in and across the plane of -polarisation; but again without any visible effect. Then he tries on -the same bodies, and on water, the “tension” of a rapidly alternating -induced current, but still with the same negative result. Professor -Tyndall stated that from conversation with Faraday, and with his -faithful assistant Anderson, he inferred that the labour expended on -this preliminary and apparently fruitless research was very great. -It occupies many pages of the laboratory notebook. That thirty-two -years later Dr. Kerr succeeded in finding this optical effect of -electrostatic strain for which Faraday vainly sought, is no reflection -upon Faraday’s powers of observation. Had there been no Faraday there -had doubtless been no discovery by Kerr. - -So far the quest had been carried on either with electric currents -flowing through the transparent substance or else with mere statical -electric forces, and a whole fortnight had been spent without result. -Now another track is taken, and it leads straight to success. He -substitutes magnetic for electric forces. - -[Sidenote: MAGNETO-OPTIC DISCOVERY.] - -“13th Sept. 1845. - -[Illustration: FIG. 15.] - -“To-day worked with lines of magnetic force, passing them across -different bodies transparent in different directions, and at the same -time passing a polarized ray of light through them, and afterwards -examining the ray by a Nichol’s Eye-piece or other means. The magnets -were Electro-magnets one being our large cylinder Electro-magnet and -the other a temporary iron core put into the helix on a frame. This was -not nearly so strong as the former. The current of 5 cells of Grove’s -battery was sent through both helices at once and the magnets were -made and unmade by putting in or stopping off the electric current.” -Air, flint-glass, rock-crystal, calcareous spar, were examined, but -without effect. And so he worked on through the morning, trying first -one specimen, then another, altering the directions of the poles of -his magnets, reversing their polarity, changing the position of his -optical apparatus, increasing the battery-power of his magnetising -current. Then he bethinks him of that “heavy-glass”--the boro-silicate -of lead--which had cost him nearly four years of precious labour during -the first period of his scientific life. The entry in the notebook is -characteristic. - -[Illustration: FIG. 16.] - -“A piece of heavy glass, which was 2 inches by 1·8 inches and 0·5 of -an inch thick, being a silico-borate of lead, was experimented with. -It gave no effects when the _same magnetic poles_ or the _contrary_ -poles were on opposite sides (as respects the course of the polarised -ray);--nor when the same poles were on the same side either with the -constant or intermitting current; =BUT= when contrary magnetic poles -were on the same side there _was an effect produced on the polarised -ray_, and thus magnetic force and light were proved to have relations -to each other. This fact will most likely prove exceedingly fertile, -and of great value in the investigation of conditions of natural force. - -“The effect was of this kind. The glass, a result of one of my old -experiments on optical glass, had been exceedingly well annealed -so that it did not in any degree affect the polarized ray. The two -magnetic poles were in a horizontal plane, and the piece of glass put -up flat against them so that the polarized ray could pass through its -edges and be examined by the eye at a Nicholl’s eye piece. In its -natural state the glass had no effect on the polarized ray but on -making contact at the battery so as to render the cores N and S magnets -instantly the glass acquired a certain degree of _power of depolarizing -the ray_ which it retained steadily as long as the cores were magnets -but which it lost the instant the electric current was stopped. Hence -it was a permanent condition and as was expected did not sensibly -appear with an intermitting current. - -[Illustration: FIG. 17.] - -“The effect was not influenced by any jogging motion or any moderate -pressure of the hands on the glass. - -“The heavy glass had tinfoil coatings on its two sides but when these -were taken off the effect remained exactly the same. - -“A mass of soft iron on the outside of the _heavy glass_ greatly -_diminished_ the effect [see Fig. 17].... - -“All this shews that it is when the _polarized ray_ passes _parallel_ -to the _lines of magnetic induction_ or rather to the _direction of -the magnetic curves_, that the glass manifests its power of affecting -the ray. So that the heavy glass in its magnetized state corresponds to -the cube of rock crystal: the direction of the magnetic curves in the -piece of glass corresponding to the direction of the optic axis in the -crystal (see Exp. Researches 1689–1698).... - -[Illustration: FIG. 18.] - -“Employed our large _ring electro-magnet_ which is very powerful and -has of course the poles in the right [position] only they are very -close not more than [0·5] of an inch apart. When the _heavy glass_ was -put up against it the effect was produced better than in any former -case.... - -[Sidenote: ENOUGH FOR TO-DAY.] - -“Have got enough for to-day.” - -The description which he published in the “Researches” of the first -successful experiment is as follows:-- - -“A piece of this glass about 2 inches square and 0·5 of an inch thick, -having flat and polished edges, was placed as a _diamagnetic_[47] -between the poles (not as yet magnetized by the electric current), -so that the polarized ray should pass through its length; the glass -acted as air, water, or any other indifferent substance would do; and -if the eye-piece [_i.e._ analyzer] were previously turned into such a -position that the polarized ray was extinguished, or rather the image -produced by it rendered invisible, then the introduction of this glass -made no alteration in that respect. In this state of circumstances -the force of the electromagnet was developed, by sending an electric -current through its coils, and immediately the image of the lamp-flame -became visible, and continued so as long as the arrangement continued -magnetic. On stopping the electric current, and so causing the magnetic -force to cease, the light instantly disappeared; these phænomena could -be renewed at pleasure, at any instant of time, and upon any occasion, -showing a perfect dependence of cause and effect.” - -He paused for four days in order to procure more powerful -electromagnets, for the effect which he had observed was exceedingly -slight: “A person looking for the phænomenon for the first time would -not be able to see it with a weak magnet.” - -The entry in the notebook begins again:-- - -“18th Sept. 1845. - -“Have now borrowed and received the Woolwich magnet.” - -[Sidenote: AN EXCELLENT DAY’S WORK.] - -This was a more powerful electromagnet than that at the Institution. -With this he sets to work with such energy that twelve pages of the -laboratory book are filled in one day. His thoughts had ripened during -the five days, and he advanced rapidly from point to point. The first -experiment with the Woolwich magnet brings out another point, of which -at once he grasped the significance:-- - -“Heavy Glass (original, or 174[48]) when placed thus produced a very -fine effect. The brightness of the image produced rose gradually not -instantly, due to this that the iron cores do not take their full -intensity of magnetic state at once but require time, and so the -magnetic curves rise in intensity. In this way the effect is one by -which an optical examination of the electromagnet can be made--and the -time necessary clearly shewn.” - -He next ascertains definitely that the phenomenon is one of rotatory -polarisation--that is to say, the action of the magnet is to twist and -rotate the plane of polarisation through a definite angle depending on -the strength of the magnet and the direction of the exciting current. -He finds the direction of the rotation, and verifies it by comparison -with the ordinary optical rotation produced by turpentine and by a -solution of sugar, winding up with the words:-- - -“_An excellent day’s work._” - -For four days he went on accumulating proofs, and now succeeding with -the very substances with which he formerly failed. On September 26th -he tried the conjoint effect of a magnetic and an electric field. -He also tried the effect of a current running along a transparent -liquid electrolytically whilst the magnet was in operation. The only -results appeared to be those due to the magnet alone. For six days in -October the experiments were continued. He noted, as a desideratum, a -transparent oxide of iron. “With some degree of curiosity and hope” he -“put gold leaf into the magnetic lines, but could perceive no effect.” -He was instinctively looking for the phenomenon which Kundt later -discovered as a property of thin transparent films of iron. He entered -amongst the speculative suggestions in his notebook the query: “Does -this [magnetic] force tend to make iron and oxide of iron transparent?” -On October 3rd he tried experiments on light reflected from the surface -of metals placed in the magnetic field. He indeed obtained an optical -rotation by reflection at the surface of a polished steel button, but -the results were inconclusive owing to imperfection of the surface. It -was reserved for Dr. Kerr to rediscover and follow up this effect. On -October 6th he looked for mechanical and magnetic effects on pieces -of heavy-glass and on liquids in glass bulbs placed between the poles -of his magnet, but found none. He also looked for possible effects of -rapid motion given to the diamagnetic while jointly subject to the -action of magnetism and the light, but found none. - -[Sidenote: UNFULFILLED EXPECTATIONS.] - -On October 11th he thinks he has got hold of another new fact when -experimenting on liquids in a long glass tube, the record of it -filling three pages. But two days afterwards he finds it only a -disturbing effect due to the communication of heat to the liquid -from the surrounding magnetising coil. He seems to regret the loss -of the new fact, but adds: “As to the other phenomenon of circular -polarization, that comes out constant, clear, and beautiful.” - -Then, with that idea of the correlation of forces always in his -head, there recurs to him the notion that if magnetism or electric -currents can affect a beam of light, there must be some sort of -converse phenomenon, and that in some way or other light must be able -to electrify or to magnetise. Thirty-one years before, when visiting -Rome with Davy, he had witnessed the experiments of Morichini on the -alleged magnetic effect of violet light, and had remained unconvinced. -His own idea is very different. And October 14th being a bright day -with good sunlight, he makes the attempt. Selecting a very sensitive -galvanometer, he connects it to a spiral of wire 1 inch in diameter, -4·2 inches long, of 56 convolutions, and then directs a beam of -sunlight along its axis. He tries letting the beam pass alternately -through the coil while the outside is covered, and then along the -exterior while the interior is shaded. But still there is no effect. -Then he inserts an unmagnetised steel bar within the coil, and rotates -it while it is exposed to the sun’s rays. Still there is no effect, -and the sun goes down on another of the unfulfilled expectations. But -had he lived to learn of the effect of light in altering the electric -resistance of selenium discovered by Mayhew, of the photoelectric -currents discovered by Becquerel, of the discharging action of -ultra-violet light discovered by Hertz, of the revivifying effect of -light on recently demagnetised iron discovered by Bidwell, he would -have rejoiced that such other correlations should have been found, -though different from that which he sought. On November 3rd he receives -a new horseshoe magnet, with which he hoped to find some optical effect -on air and other gases, but again without result. That the magnetism of -the earth does actually rotate the plane of polarisation of sky light -was the discovery of Henri Becquerel so late as 1878. - -Faithful to his own maxim: “Work, finish, publish,” Faraday lost no -time in writing out his research. It was presented to the Royal Society -on November 6th, but the main result was verbally mentioned on November -3rd at the monthly meeting of the Royal Institution, and reported in -the _Athenæum_ of November 8th, 1845. - -But even before the memoir was thus given to the world another -discovery had been made. For on November 4th with the new magnet he -repeated an experiment which a month previously had been without -result. So preoccupied was he over the new event that he did not even -go to the meeting of the Royal Society on November 20th, when his paper -on the “Action of Magnets on Light” was read. What that new discovery -was is well told by Faraday himself in the letter which he sent to -Professor A. de la Rive on December 4th:-- - -[Sidenote: FRESH MAGNETIC DISCOVERY.] - - [_Faraday to Professor Aug. de la Rive._] - - Brighton, December 4, 1845. - - MY DEAR FRIEND,-- * * * I count upon you as one of those whose - free hearts have pleasure in my success, and I am very grateful - to you for it. I have had your last letter by me on my desk - for several weeks, intending to answer it; but absolutely I - have not been able, for of late I have shut myself up in my - laboratory and wrought, to the exclusion of everything else. I - heard afterwards that even your brother had called on one of - these days and been excluded. - - Well, a part of this result is that which you have heard, - and my paper was read to the Royal Society, I believe, last - Thursday, for I was not there; and I also understand there have - been notices in the _Athenæum_, but I have not had time to see - them, and I do not know how they are done. However, I can refer - you to the _Times_ of last Saturday (November 29th) for a very - good abstract of the paper. I do not know who put it in, but it - is well done, though brief. To that account, therefore, I will - refer you. - - For I am still so involved in discovery that I have hardly - time for my meals, and am here at Brighton both to refresh - and work my head at once, and I feel that unless I had been - here, and been careful, I could not have continued my labours. - The consequence has been that last Monday I announced to our - members at the Royal Institution another discovery, of which I - will give you the pith in a few words. The paper will go to the - Royal Society next week, and probably be read as shortly after - as they can there find it convenient. - - Many years ago I worked upon optical glass, and made a vitreous - compound of silica, boracic acid, and lead, which I will - now call heavy glass, and which Amici uses in some of his - microscopes; and it was this substance which enabled me first - to act on light by magnetic and electric forces. Now, if a - square bar of this substance, about half an inch thick and - two inches long, be very freely suspended between the poles - of a powerful horse-shoe electro-magnet, immediately that - the magnetic force is developed, the bar points; but it does - not point from pole to pole, but equatorially or across the - magnetic lines of force--_i.e._ east and west in respect of - the north and south poles. If it be moved from this position - it returns to it, and this continues as long as the magnetic - force is in action. This effect is the result of a still - simpler action of the magnet on the bar than what appears by - the experiment, and which may be obtained at a single magnetic - pole. For if a cubical or rounded piece of the glass be - suspended by a fine thread six or eight feet long, and allowed - to hang very near a strong magneto-electric pole (not as yet - made active), then on rendering the pole magnetic the glass - will be repelled, and continue repelled until the magnetism - ceases. This effect or power I have worked out through a great - number of its forms and strange consequences, and they will - occupy two series of the “Experimental Researches.” It belongs - to _all matter_ (not magnetic, as iron) without exception, - so that every substance belongs to the one or the other - class--magnetic or diamagnetic bodies. The law of action in - its simple form is that such matter tends to go from strong to - weak points of magnetic force, and in doing this the substance - will go in either direction along the magnetic curves, or in - either direction across them. It is curious that amongst the - metals are found bodies possessing this property in as high a - degree as perhaps any other substance. In fact, I do not know - at present whether heavy glass, or bismuth, or phosphorus is - the most striking in this respect. I have very little doubt - that you have an electro-magnet strong enough to enable you to - verify the chief facts of pointing equatorially and repulsion, - if you will use bismuth carefully examined as to its freedom - from magnetism, and making of it a bar an inch and a half long, - and one-third or one-fourth of an inch wide. Let me, however, - ask the favour of your keeping this fact to yourself for two - or three weeks, and preserving the date of this letter as a - record. I ought (in order to preserve the respect due to the - Royal Society) not to write a description to anyone until the - paper has been received or even read there. After three weeks - or a month I think you may use it, guarding, as I am sure you - will do, my right. And now, my dear friend, I must conclude, - and hasten to work again. But first give my kindest respects to - Madame de la Rive, and many thanks to your brother for his call. - - Ever your obedient and affectionate friend, - - M. FARADAY. - - -[Sidenote: MAGNETIC EXPERIMENTS.] - -The discovery of diamagnetism which Faraday thus announced was in -itself a notable achievement. As Tyndall points out, the discovery -itself was in all probability due to Faraday’s habit of not regarding -as final any negative result of an experiment until he had brought to -bear upon it the most powerful resources at his command. He had tried -the effects of ordinary magnets on brass and copper and other materials -commonly considered as non-magnetic. But when, for the purpose of -the preceding research on the relation of magnetism to light, he had -deliberately procured electromagnets of unusual power, he again tried -what their effect might be upon non-magnetic stuffs. Suspending a piece -of his heavy glass near the poles in a stirrup of writing-paper slung -upon the end of a long thread of cocoon silk, he found it to experience -a strong mechanical action when the magnet was stimulated by turning on -the current. His precision of description is characteristic:-- - - I shall have such frequent occasion to refer to two chief - positions of position across the magnetic field, that, to - avoid periphrasis, I will here ask leave to use a term or two - conditionally. One of these directions is that from pole to - pole, or along the lines of magnetic force, I will call it the - axial direction; the other is the direction perpendicular to - this, and across the line of magnetic force and for the time, - and as respects the space between the poles, I will call it the - _equatorial_ direction. - -Note the occurrence in the above passage for the first time of the term -“the magnetic field.” Faraday’s description of the discovery continues -as follows:-- - - The bar of silicated borate of lead or heavy glass already - described as the substance in which magnetic forces were first - made effectually to bear on a ray of light, and which is 2 - inches long, and about 0·5 inch wide and thick, was suspended - centrally between the magnetic poles, and left until the effect - of torsion was over. The magnet was then thrown into action - by making contact at the voltaic battery. Immediately the bar - moved, turning round its point of suspension, into a position - across the magnetic curve or line of force, and, after a few - vibrations, took up its place of rest there. On being displaced - by hand from this position it returned to it, and this occurred - many times in succession. - - [Illustration: FIG. 19.] - - Either end of the bar indifferently went to either side of the - axial line. The determining circumstance was simply inclination - of the bar one way or the other to the axial line at the - beginning of the experiment. If a particular or marked end of - the bar were on one side of the magnetic or axial line when - the magnet was rendered active, that end went further outwards - until the bar had taken up the equatorial position.... - - Here, then, we have a magnetic bar which points east and - west in relation to north and south poles--_i.e._ points - perpendicularly to the lines of magnetic force.... - - [Sidenote: DIAMAGNETIC LAWS.] - - To produce these effects of pointing across the magnetic - curves, the form of the heavy glass must be long. A cube or - a fragment approaching roundness in form will not point, but - a long piece will. Two or three rounded pieces or cubes, - placed side by side in a paper tray, so as to form an oblong - accumulation, will also point. - - Portions, however, of any form are _repelled_; so if two pieces - be hung up at once in the axial line, one near each pole, they - are repelled by their respective poles, and approach, seeming - to attract each other. Or if two pieces be hung up in the - equatorial line, one on each side of the axis, then they both - recede from the axis, seeming to repel each other. - - From the little that has been said, it is evident that the - bar presents in its motion a complicated result of the force - exerted by the magnetic power over the heavy glass, and that - when cubes or spheres are employed a much simpler indication of - the effect may be obtained. Accordingly, when a cube was thus - used with the two poles, the effect was repulsion or recession - from either pole, and also recession from the magnetic axis on - either side. - - So the indicating particle would move either along the magnetic - curves or across them, and it would do this either in one - direction or the other, the only constant point being that its - tendency was to move from stronger to weaker places of magnetic - force. - - This appeared much more simply in the case of a single magnetic - pole, for then the tendency of the indicating cube or sphere - was to move outwards in the direction of the magnetic lines - of force. The appearance was remarkably like a case of weak - electric repulsion. - - The cause of the pointing of the bar, or any oblong arrangement - of the heavy glass, is now evident. It is merely a result of - the tendency of the particles to move outwards, or into the - positions of weakest magnetic action. - - * * * * * - - When the bar of heavy glass is immersed in water, alcohol, - or æther, contained in a vessel between the poles, all the - preceding effects occur--the bar points and the cube recedes - exactly in the same manner as in air. - - The effects equally occur in vessels of wood, stone, earth, - copper, lead, silver, or any of those substances which belong - to the diamagnetic class. - - I have obtained the same equatorial direction and motions of - the heavy glass bar as those just described, but in a very - feeble degree, by the use of a good common steel horseshoe - magnet. - -Then he goes on to enumerate the many bodies of all sorts: crystals, -powders, liquids, acids, oils; organic bodies such as wax, olive-oil, -wood, beef (fresh and dry), blood, apple, and bread, all of which were -found to be diamagnetic. On this he remarks:-- - - It is curious to see such a list as this of bodies presenting - on a sudden this remarkable property, and it is strange to find - a piece of wood, or beef, or apple, obedient to or repelled by - a magnet. If a man could be suspended with sufficient delicacy - after the manner of Dufay, and placed in the magnetic field, he - would point equatorially, for all the substances of which he is - formed, including the blood, possess this property. - -[Sidenote: THE MAGNETIC BRAKE.] - -A few bodies were found to be feebly magnetic, including paper, -sealing-wax, china ink, asbestos, fluorspar, peroxide of lead, -tourmaline, plumbago, and charcoal. As to the metals, he found iron, -cobalt, and nickel to stand in a distinct class. A feeble magnetic -action in platinum, palladium, and titanium was suspected to be due -to traces of iron in them. Bismuth proved to be the most strongly -diamagnetic, and was specially studied. The repellent effect between -bismuth and a magnet had indeed been casually observed twice in the -prior history of science, first by Brugmans, then by Le Baillif. -Faraday, with characteristic frankness, refers to his having a “vague -impression” that the repulsion of bismuth by a magnet had been -observed before, though unable at the time of writing to recollect any -reference. His own experiments ran over the whole range of substances, -however, and demonstrated the universal existence in greater or less -degree of this magnetic nature. Certain differences observed between -the behaviour of bismuth and of heavy glass on the one hand, and -of copper on the other hand, though all are diamagnetic, led him -to note and describe some of the pseudo-diamagnetic effects which -occur in copper and silver, in consequence of the induction in them -of eddy-currents, from which heavy-glass and bismuth are, by their -inferior electric conductivity, comparatively free. He described the -beautiful and now classical experiment of arresting, by turning on the -exciting current, the rotation of a copper cylinder spinning between -the poles of an electromagnet. - -Faraday continued to prosecute this newest line of research, and at -the end of December, 1845, presented another memoir (the twenty-first -series of the Experimental Researches) to the Royal Society. He had now -examined the salts of iron, and had found that every salt and compound -containing iron in the basic part was magnetic, both in the solid -and in the liquid state. Even prussian-blue and green bottle-glass -were magnetic. The solutions of the salts of iron were of special -importance, since they furnish the means of making a magnet which -is for the time liquid, transparent, and, within certain limits, -adjustable in strength. His next step was to examine how bodies -behaved when immersed in some surrounding medium. A weak solution of -iron, enclosed in a very thin glass tube, though it pointed axially -when hung in air, pointed equatorially when immersed in a stronger -solution. A tube full of air pointed axially, and was attracted as -if magnetic when surrounded with water. Substances such as bismuth, -copper, and phosphorus are, however, highly diamagnetic when suspended -_in vacuo_. Such a view would make _mere space_ magnetic. Hence Faraday -inclined at first to the opinion that diamagnetics had a specific -action antithetically distinct from ordinary magnetic action. Several -times he pointed out that all the phenomena resolve themselves simply -into this, that a portion of such matter as is termed diamagnetic -tends to move from stronger to places or points of weaker force in -the magnetic field. He does, indeed, hazard the suggestion that the -phenomena might be explained on the assumption that there was a sort of -diamagnetic polarity--that magnetic induction caused in them a contrary -state to that which it produced in ordinary magnetic matter. But his -own experiments failed to support this view, and, in opposition to -Weber and Tyndall, he maintained afterwards the non-polar nature of -diamagnetic action. - -In 1846 Faraday gave two Friday night discourses on these magnetic -researches, one on the cohesive force of water, and one on Wheatstone’s -electromagnetic chronoscope. At the conclusion of the last-named he -said that he was induced to utter a speculation which had long been -gaining strength in his mind, that perhaps those vibrations by which -radiant energies, such as light, heat, actinic rays, etc., convey -their force through space are not mere vibrations of an æther, but of -the lines of force which, in his view, connect different masses, and -so was inclined, in his own phrase, “to dismiss the æther.” In one of -his other discourses he made the suggestion that we might “perhaps -hereafter obtain magnetism from light.” - -[Sidenote: THOUGHTS ON RAY VIBRATIONS.] - -The speculation above referred to is of such intrinsic importance, in -view of the developments of the last decade, that it compels further -notice. Faraday himself further expanded it in a letter to Richard -Phillips, which was printed in the _Philosophical Magazine_ for May, -1846, under the title “Thoughts on Ray-vibrations.” In this avowedly -speculative paper Faraday touched the highest point in his scientific -writings, and threw out, though in a tentative and fragmentary way, -brilliant hints of that which his imagination had perceived, as in -a vision;--the doctrine now known as the electromagnetic theory of -light. At the dates when the earlier biographies of Faraday appeared, -neither that doctrine nor this paper had received the recognition due -to its importance. Tyndall dismisses it as “one of the most singular -speculations that ever emanated from a scientific man.” Bence Jones -just mentions it in half a line. Dr. Gladstone does not allude to it. -It therefore seems expedient to give here some extracts from the letter -itself:-- - - THOUGHTS ON RAY-VIBRATIONS. - - _To Richard Phillips, Esq._ - - DEAR SIR,--At your request, I will endeavour to convey to you a - notion of that which I ventured to say at the close of the last - Friday evening meeting ...; but, from first to last, understand - that I merely threw out, as matter for speculation, the vague - impressions of my mind, for I gave nothing as the result of - sufficient consideration, or as the settled conviction, or even - probable conclusion at which I had arrived. - - The point intended to be set forth for the consideration - of the hearers was whether it was not possible that the - vibrations--which in a certain theory are assumed to account - for radiation and radiant phenomena--may not occur in the lines - of force which connect particles, and consequently masses, of - matter together--a notion which, as far as it is admitted, will - dispense with the æther, which, in another view, is supposed to - be the medium in which these vibrations take place. - - * * * * * - - Another consideration bearing conjointly on the hypothetical - view, both of matter and radiation, arises from the comparison - of the velocities with which the radiant action and certain - powers of matter are transmitted. The velocity of light through - space is about 190,000 miles[49] a second. The velocity of - electricity is, by the experiments of Wheatstone, shown to be - as great as this, if not greater. The light is supposed to be - transmitted by vibrations through an æther which is, so to - speak, destitute of gravitation, but infinite in elasticity; - the electricity is transmitted through a small metallic wire, - and is often viewed as transmitted by vibrations also. That - the electric transference depends on the forces or powers of - the matter of the wire can hardly be doubted when we consider - the different conductibility of the various metallic and - other bodies, the means of affecting it by heat or cold, the - way in which conducting bodies by combination enter into the - constitution of non-conducting substances, and the contrary, - and the actual existence of one elementary body (carbon) - both in the conducting and non-conducting state. The power - of electric conduction, being a transmission of force equal - in velocity to that of light, appears to be tied up in and - dependent upon the properties of the matter, and is, as it - were, existent in them. - - * * * * * - - [Sidenote: LATERAL VIBRATIONS.] - - [Illustration: FIG. 20.] - - In experimental philosophy we can, by the phenomena presented, - recognise various kinds of lines of force. Thus there are the - lines of gravitating force, those of electrostatic induction, - those of magnetic action, and others partaking of a dynamic - character might be perhaps included. The lines of electric - and magnetic action are by many considered as exerted through - space like the lines of gravitating force. For my own part, I - incline to believe that when there are intervening particles - of matter--being themselves only centres of force--they take - part in carrying on the force through the line, but that when - there are none the line proceeds through space. Whatever the - view adopted respecting them may be, we can, at all events, - affect these lines of force in a manner which may be conceived - as partaking of the nature of a shake or lateral vibration. - For suppose two bodies, A B, distant from each other, and - under mutual action,[50] and therefore connected by lines of - force, and let us fix our attention upon one resultant of force - having an invariable direction as regards space; if one of - the bodies move in the least degree right or left, or if its - power be shifted for a moment within the mass (neither of these - cases being difficult to realise if A or B be either electric - or magnetic bodies), then an effect equivalent to a lateral - disturbance will take place in the resultant upon which we are - fixing our attention, for either it will increase in force - whilst the neighbouring resultants are diminishing, or it will - fall in force while they are increasing. - - * * * * * - - The view which I am so bold as to put forth considers, - therefore, radiation as a high species of vibration in the - lines of force which are known to connect particles, and also - masses, of matter together. It endeavours to dismiss the æther, - but not the vibrations. The kind of vibration which, I believe, - can alone account for the wonderful, varied, and beautiful - phenomena of polarisation is not the same as that which occurs - on the surface of disturbed water or the waves of sound in - gases or liquids, for the vibrations in these cases are direct, - or to and from the centre of action, whereas the former are - lateral. It seems to me that the resultant of two or more lines - of force is in an apt condition for that action, which may be - considered as equivalent to a _lateral_ vibration; whereas a - uniform medium like the æther does not appear apt, or more apt - than air or water. - - The occurrence of a change at one end of a line of force easily - suggests a consequent change at the other. The propagation of - light, and therefore probably of all radiant action, occupies - _time_; and that a vibration of the line of force should - account for the phenomena of radiation, it is necessary that - such vibration should occupy time also. - - * * * * * - - [Sidenote: THE SHADOW OF A SPECULATION.] - - And now, my dear Phillips I must conclude. I do not think I - should have allowed these notions to have escaped from me had - I not been led unawares, and without previous consideration, - by the circumstances of the evening on which I had to appear - suddenly[51] and occupy the place of another. Now that I have - put them on paper, I feel that I ought to have kept them much - longer for study, consideration, and perhaps final rejection; - and it is only because they are sure to go abroad in one - way or another, in consequence of their utterance on that - evening, that I give them a shape, if shape it may be called, - in this reply to your inquiry. One thing is certain, that any - hypothetical view of radiation which is likely to be received - or retained as satisfactory must not much longer comprehend - alone certain phenomena of light, but must include those of - heat and of actinic influence also, and even the conjoined - phenomena of sensible heat and chemical power produced by - them. In this respect a view which is in some degree founded - upon the ordinary forces of matter may perhaps find a little - consideration amongst the other views that will probably - arise. I think it likely that I have made many mistakes in the - preceding pages, for even to myself my ideas on this point - appear only as the shadow of a speculation, or as one of those - impressions on the mind which are allowable for a time as - guides to thought and research. He who labours in experimental - inquiries knows how numerous these are, and how often their - apparent fitness and beauty vanish before the progress and - development of real, natural truth. - - I am, my dear Phillips, - Ever truly yours, - M. FARADAY. - - _Royal Institution_, - _April 15, 1846_. - - -If it be thought that too high a value has here been set upon a -document which its author himself only claimed to be “the shadow of -a speculation,” let that value be justified out of the mouth of the -man who eighteen years later enriched the world with the mathematical -theory of the propagation of electric waves, the late Professor Clerk -Maxwell. In 1864 he published in the _Philosophical Transactions_ a -“Dynamical Theory of the Electromagnetic Field,” in which the following -passages occur:-- - - We have therefore reason to believe, from the phenomena of - light and heat, that there is an æthereal medium filling - space and permeating bodies capable of being set in motion, - and of transmitting that motion to gross matter, so as to - heat it and affect it in various ways.... Hence the parts - of this medium must be so connected that the motion of one - part depends in some way on the motion of the rest; and at - the same time these connections must be capable of a certain - kind of elastic yielding, since the communication of motion - is not instantaneous, but occupies time. The medium is - therefore capable of receiving and storing up two kinds of - energy--namely, the “actual” energy depending on the motion of - its parts, and “potential” energy, consisting of the work which - the medium will do in recovering from displacement in virtue of - its elasticity. - - The propagation of undulations consists in the continual - transformation of one of these forms of energy into the other - alternately, and at any instant the amount of energy in the - whole medium is equally divided, so that half is energy of - motion and half is elastic resilience. - - * * * * * - - In order to bring these results within the power of symbolic - calculation, I then express them in the form of the general - equations of the electromagnetic field. - - * * * * * - - The general equations are next applied to the case of a - magnetic disturbance propagated through a non-conducting field, - and it is shown that the only disturbances which can be so - propagated are those which are transverse to the direction - of propagation, and that the velocity of propagation is - the velocity _v_, found from experiments such as those of - Weber, which expresses the number of electrostatic units of - electricity which are contained in one electromagnetic unit. - This velocity is so nearly that of light, that it seems we have - strong reason to conclude that light itself (including radiant - heat and other radiations, if any) is an electromagnetic - disturbance in the form of waves propagated through the - electromagnetic field according to electromagnetic laws.... - Conducting media are shown to absorb such radiations rapidly, - and therefore to be generally opaque. - - [Sidenote: ELECTROMAGNETIC THEORY OF LIGHT.] - - The conception of the propagation of transverse magnetic - disturbances to the exclusion of normal ones is distinctly set - forth by Professor Faraday in his “Thoughts on Ray Vibrations.” - _The electromagnetic theory of light, as proposed by him, is - the same in substance as that which I have begun to develop - in this paper_,[52] except that in 1846 there were no data to - calculate the velocity of propagation. - -During the rest of this year (1846) and the next Faraday did very -little research, though he continued his Royal Institution lectures and -his reports for Trinity House. Amongst the latter in 1847 was one on -a proposal to light buoys by incandescent electric lamps containing a -platinum wire spiral. He was compelled, indeed, to rest by a recurrence -of brain troubles, giddiness, and loss of memory. Honours however, -continued to be heaped upon him both abroad and at home, as the -following extract from Bence Jones shows:-- - - In 1846, for his two great discoveries, the Rumford and the - Royal Medals were both awarded to him. This double honour - will probably long be unique in the annals of the Royal - Society. In former years he had already received the Copley - and Royal Medals for his experimental discoveries. As his - medals increased it became remarkable that he--who kept his - diploma-book, his portraits and letters of scientific men, and - everything he had in the most perfect order--seemed to take - least care of his most valuable rewards. They were locked up in - a box, and might have passed for old iron. Probably he thought, - as others did afterwards, that their value, if seen, might lead - to their loss. - -[Sidenote: CRYSTALLINE FORCES.] - -Between the twenty-first and twenty-second series of “Experimental -Researches” nearly three years elapsed. In the autumn of 1848 the -matter which claimed investigation was the peculiar behaviour of -bismuth in the magnetic field. Certain anomalies were observed -which were finally traced to the crystalline nature of the metal, -for it appeared that when in that state the crystals themselves--to -adopt modern phraseology--showed a greater magnetic permeability in -a direction perpendicular to their planes of cleavage than in any -direction parallel to those planes. Hence when a crystalline fragment -was hung in a _uniform_ magnetic field (where the diamagnetic tendency -to move from a strong to a weak region of the field was eliminated), -it tended to point in a determinate direction. Faraday expressed it -that the structure of the crystal showed a certain “axiality,” and he -regarded these effects as presenting evidence of a “magnecrystallic” -force, the law of action being that the line or axis of magnecrystallic -force tended to place itself parallel to the lines of the magnetic -field in which the crystal was placed. Arsenic, antimony, and other -crystalline metals were similarly examined. The subject was an -intricate one, and there are frequent obscurities in the phraseology -tentatively adopted for explaining the phenomena. In one place Faraday -rather pathetically laments his imperfect mathematical knowledge. -This seems like an echo of his inability to follow the analytical -reasoning of Poisson, who, starting from a hypothesis about the -supposed “magnetic fluids” being movable within the particles of a -body, supposing that these particles were non-spherical and were -symmetrically arranged, had predicted (in 1827) that a portion of such -a substance would, when brought into the neighbourhood of a magnet, -act differently, according to the different positions in which it -might be turned about its centre. But this very inability to follow -Poisson’s refined analysis gave a new direction to Faraday’s thoughts, -and caused him to conceive the idea of magnetic permeabilities -differing in different directions, an idea which, as Sir William -Thomson (the present Lord Kelvin) showed in 1851,[53] is equally -susceptible of mathematical treatment by appropriate symbols. Lord -Kelvin has also spoken (_op. cit._, p. 484) of the matter as follows: -“The singular combination of mathematical acuteness with experimental -research and profound physical speculation which Faraday, though not -a ‘mathematician,’ presented is remarkably illustrated by his use of -the expression ‘_conducting power of a magnetic medium for lines of -force_.’” Tyndall has given a succinct summary of these researches--in -which also he took a part--from which the following extract must -suffice:-- - - And here follows one of those expressions which characterise - the conceptions of Faraday in regard to force generally: “It - appears to me impossible to conceive of the results in any - other way than by a mutual reaction of the magnetic force, and - the force of the particles of the crystal upon each other.” He - proves that the action of the force, though thus molecular, - is an action at a distance. He shows that a bismuth crystal - can cause a freely-suspended magnetic needle to set parallel - to its magnecrystallic axis. Few living men are aware of the - difficulty of obtaining results like this, or of the delicacy - necessary to their attainment. “But though it thus takes up the - character of a force acting at a distance, still it is due to - that power of the particles which makes them cohere in regular - order and gives the mass its crystalline aggregation, and so - often spoken of as acting at _insensible_ distances.” Thus he - broods over this new force, and looks at it from all points of - inspection. Experiment follows experiment, as thought follows - thought. He will not relinquish the subject as long as a hope - exists of throwing more light upon it. He knows full well the - anomalous nature of the conclusion to which his experiments - lead him. But experiment to him is final, and he will not - shrink from the conclusion. “This force,” he says, “appears to - me to be very strange and striking in its character. It is not - polar, for there is no attraction or repulsion.” And then, as - if startled by his own utterance, he asks: “What is the nature - of the mechanical force which turns the crystal round and makes - it affect a magnet?”... “I do not remember,” he continues, - “heretofore such a case of force as the present one--where - a body is brought into position only without attraction or - repulsion.” - - Plücker, the celebrated geometer already mentioned, who pursued - experimental physics for many years of his life with singular - devotion and success, visited Faraday in those days, and - repeated before him his beautiful experiments on magneto-optic - action. Faraday repeated and verified Plücker’s observations, - and concluded, what he at first seemed to doubt, that Plücker’s - results and magnecrystallic action had the same origin. - - [Sidenote: MAGNETISM AND CRYSTALLISATION.] - - At the end of his papers, when he takes a last look along - the line of research, and then turns his eyes to the future, - utterances quite as much emotional as scientific escape from - Faraday. “I cannot,” he says at the end of his first paper on - magnecrystallic action, “conclude this series of researches - without remarking how rapidly the knowledge of molecular forces - grows upon us, and how strikingly every investigation tends - to develop more and more their importance and their extreme - attraction as an object of study. A few years ago magnetism was - to us an occult power, affecting only a few bodies. Now it is - found to influence all bodies, and to possess the most intimate - relations with electricity, heat, chemical action, light, - crystallisation, and through it with the forces concerned in - cohesion. And we may, in the present state of things, well feel - urged to continue in our labours, encouraged by the hope of - bringing it into a bond of union with gravity itself.” - -In 1848 Faraday gave five Friday night discourses, three of them on -the “Diamagnetic Condition of Flame and Gases.” In 1849 he gave two, -one of them on Plücker’s researches. In 1850 he gave two, one of them -being on the electricity of the air, the other on certain conditions of -freezing water. He had meanwhile continued to work at magnetism. The -twenty-third series dealt with the supposed diamagnetic polarity. It -incidentally discussed the distortion produced in a magnetic field by -a mass of copper in motion across it. The twenty-fourth series was on -the possible relation of gravity to electricity. The paper concludes -with the words: “Here end my trials for the present. The results are -negative. They do not shake my strong feeling of the existence of a -relation between gravity and electricity, though they give no proof -that such a relation exists.” The next series (the twenty-fifth) was -on the “Non-expansion of Gases by Magnetic Force” and on the “Magnetic -Characters of Oxygen [which he had found to be highly magnetic], -Nitrogen, and Space.” He had found that magnetically substances must be -classed either along with iron and the materials that point axially, or -else with bismuth and those that point equatorially, in the magnetic -field. The best vacuum he could procure he regarded as the zero of -these tests; but before adopting it as such, he verified by experiment -that even in a vacuum a magnetic body still tends from weaker to -stronger places in the magnetic field; while diamagnetic bodies tend -from stronger to weaker. He then says we must consider the magnetic -character and relation of _space_ free from any material substance. -“Mere space cannot act as matter acts, even though the utmost latitude -be allowed to the hypothesis of an ether.” He then proceeds as -follows:-- - -[Sidenote: MORE NEW WORDS.] - - Now that the true zero is obtained, and the great variety of - material substances satisfactorily divided into two general - classes, it appears to me that we want another name for - the magnetic class, that we may avoid confusion. The word - _magnetic_ ought to be general, and include _all_ the phenomena - and effects produced by that power. But then a word for the - subdivision opposed to the diamagnetic class is necessary. - As the language of this branch of science may soon require - general and careful changes, I, assisted by a kind friend, have - thought that a word--not selected with particular care--might - be provisionally useful; and as the magnetism of iron, nickel, - and cobalt when in the magnetic field is like that of the - earth as a whole, so that when rendered active they place - themselves parallel to its axes or lines of magnetic force, I - have supposed that they and their similars (including oxygen - now) might be called paramagnetic bodies, giving the following - division:-- - - { paramagnetic - Magnetic { - { diamagnetic. - - -The “kind friend” alluded to was Whewell, as the following letter -shows:-- - - [_Rev. W. Whewell to M. Faraday._] - - July, 1850. - - I am always glad to hear of your wanting new words, because - the want shows that you are pursuing new thoughts--and your - new thoughts are worth something--but I always feel also how - difficult it is for one who has not pursued the train of - thought to suggest the right word. There are so many relations - involved in a new discovery, and the word ought not glaringly - to violate any of them. The purists would certainly object - to the opposition, or co-ordination, of _ferromagnetic_ and - _diamagnetic_, not only on account of the want of symmetry - in the relation of _ferro_ and _dia_, but also because the - one is Latin and the other Greek.... Hence it would appear - that the two classes of magnetic bodies are those which place - their length _parallel_, or _according_, to the terrestrial - magnetic lines, and those which place their length transverse - to such lines. Keeping the preposition _dia_ for the latter, - the preposition _para_, or _ana_, might be used for the former. - Perhaps para would be best, as the word _parallel_, in which it - is involved, would be a technical memory for it.... I rejoice - to hear that you have new views of discovery opening to you. I - always rejoice to hail the light of such when they dawn upon - you. - -The twenty-sixth series of researches opened with a consideration of -magnetic “conducting power,” or permeability as we should now term -it, and then branched off into a lengthy discussion of atmospheric -magnetism. The subject was continued through the twenty-seventh series, -which was completed in November, 1850. The gist of this is summed up in -one of his letters to Schönbein:-- - - Royal Institution, November 19, 1850. - - MY DEAR SCHÖNBEIN,--I wish I could talk with you, instead of - being obliged to use pen and paper. I have fifty matters to - speak about, but either they are too trifling for writing, or - too important, for what can one discuss or say in a letter?... - By the bye, I have been working with the oxygen of the air - also. You remember that three years ago I distinguished it as - a magnetic gas in my paper on the diamagnetism of flame and - gases founded on Bancalari’s experiment. Now I find in it the - cause of all the annual and diurnal, and many of the irregular, - variations in the terrestrial magnetism. The observations made - at Hobarton, Toronto, Greenwich, St. Petersburg, Washington, - St. Helena, the Cape of Good Hope, and Singapore, all appear - to me to accord with and support my hypothesis. I will not - pretend to give you an account of it here, for it would require - some detail, and I really am weary of the subject. I have sent - in three long papers to the Royal Society, and you shall have - copies of them in due time.... - - Ever, my dear Schönbein, most truly yours, - M. FARADAY. - - -[Sidenote: PAPERS TO BE LET LOOSE.] - -While writing out these researches for the Royal Society, he had been -staying in Upper Norwood. He wrote thus of himself to Miss Moore at -the end of August:-- - - We have taken a little house here on the hill-top, where I have - a small room to myself, and have, ever since we came here, been - deeply immersed in magnetic cogitations. I write, and write, - and write, until three papers for the Royal Society are nearly - completed, and I hope that two of them will be good if they - justify my hopes, for I have to criticise them again and again - before I let them loose. You shall hear of them at some of the - Friday evenings. At present I must not say more. After writing, - I walk out in the evening, hand-in-hand with my dear wife, to - enjoy the sunset; for to me, who love scenery, of all that I - have seen or can see there is none surpasses that of Heaven. A - glorious sunset brings with it a thousand thoughts that delight - me. - -To De la Rive he wrote later as follows:-- - - [_M. Faraday to A. de la Rive._] - - Royal Institution, February 4, 1851. - - MY DEAR DE LA RIVE,--My wife and I were exceedingly sorry to - hear of your sad loss. It brought vividly to our remembrance - the time when we were at your house, and you, and others with - you, made us so welcome. What can we say to these changes but - that they show by comparison the vanity of all things under the - sun? I am very glad that you have spirits to return to work - again, for that is a healthy and proper employment of the mind - under such circumstances. - - With respect to my views and experiments, I do not think - that anything shorter than the papers (and they will run - to a hundred pages in the “Transactions”) will give you - possession of the subject, because a great deal depends upon - the comparison of observations in different parts of the world - with the facts obtained by experiment, and with the deductions - drawn from them; but I will try to give you an idea of the root - of the matter. You are aware that I use the phrase _line of - magnetic force_, to represent the presence of magnetic force, - and the direction (of polarity) in which it is exerted; and by - the idea which it conveys one obtains very well, and I believe - without error, a notion of the distribution of the forces about - a bar magnet, or between near flat poles presenting a field - of equal force, or in any other case. Now, if circumstances - be arranged so as to present a field of equal force, which is - easily done, as I have shown by the electro-magnet, then if a - sphere of iron or nickel be placed in the field, it immediately - disturbs the direction of the lines of force, for they are - concentrated within the sphere. They are, however, not merely - concentrated, but _contorted_, for the sum of forces in any - one section across the field is always equal to the sum of - forces in any other section, and therefore their condensation - in the iron or nickel cannot occur without this contortion. - Moreover, the contortion is easily shown by using a small - needle (one-tenth of an inch long) to examine the field, for, - as before the introduction of the sphere of iron or nickel, it - would always take up a position parallel to itself. Afterwards - it varies in position in different places near the sphere. - This being understood, let us then suppose the sphere to be - raised in temperature. At a certain temperature it begins to - lose its power of affecting the lines of magnetic force, and - ends by retaining scarcely any. So that as regards the little - needle mentioned above, it now stands everywhere parallel to - itself within the field of force. This change occurs with iron - at a very high temperature, and is passed through within the - compass, apparently, of a small number of degrees. With nickel - it occurs at much lower temperatures, being affected by the - heat of boiling oil. - - Now take another step. Oxygen, as I showed above, three years - ago in the _Philosophical Magazine_ for 1847, vol. xxxi., - pp. 410, 415, 416, is magnetic in relation to nitrogen and - other gases. E. Becquerel, without knowing of my results, has - confirmed and extended them in his paper of last year, and - given certain excellent measures. In my paper of 1847 I showed - also that oxygen (like iron and nickel) lost its magnetic power - and its ability of being attracted by the magnet when heated - (p. 417). And I further showed that the temperatures at which - this took place were within the range of common temperature, - for the oxygen of the air--_i.e._ the air altogether--is - increased in magnetic power when cooled to 0° F. (p. 406). - Now I must refer you to the papers themselves for the (to - me) strange results of the incompressibility (magnetically - speaking) of oxygen and the inexpansibility of nitrogen and - other gases; for the description of a differential balance by - which I can compare gas with gas, or the same gas at different - degrees of rarefaction; for the determination of the true - zero, or point between magnetic and diamagnetic bodies; and - for certain views of magnetic conduction and polarity. You - will there find described certain very delicate experiments - upon diamagnetic and very weak magnetic bodies concerning - their action on each other in a magnetic field of equal force. - The magnetic bodies repel each other, and the diamagnetic - bodies repel each other; but a magnetic and a diamagnetic body - _attract_ each other. And these results, combined with the - qualities of oxygen as just described, convince me that it is - able to deflect the lines of magnetic force passing through it - just as iron or nickel is, but to an infinitely smaller amount, - and that its power of deflecting the lines varies with its - temperature and degree of rarefaction. - - [Sidenote: ATMOSPHERIC MAGNETISM.] - - Then comes in the consideration of the atmosphere, and the - manner in which it rises and falls in temperature by the - presence and absence of the sun. The place of the great warm - region nearly in his neighbourhood; of the two colder regions - which grow up and diminish in the northern and southern - hemispheres as the sun travels between the tropics; the - effect of the extra warmth of the northern hemisphere over - the southern; the effect of accumulation from the action of - preceding months; the effect of dip and mean declination - at each particular station; the effects that follow from - the non-coincidence of magnetic and astronomical conditions - of polarity, meridians, and so forth; the results of the - distribution of land and water for any given place--for all - these and many other things I must refer you to the papers. - I could not do them justice in any account that a letter - could contain, and should run the risk of leading you into - error regarding them. But I may say that, deducing from the - experiments and the theory what are the deviations of the - magnetic needle at any given station, which may be expected as - the mean result of the heating and cooling of the atmosphere - for a given season and hour, I find such a general accordance - with the results of observations, especially in the direction - and generally in the amount for different seasons of the - _declination_ variation, as to give me the strongest hopes that - I have assigned the true physical cause of those variations, - and shown the _modus operandi_ of their production. - - And now, my dear de la Rive, I must leave you and run to other - matters. As soon as I can send you a copy of the papers I will - do so, and can only say I hope that they will meet with your - approbation. With the kindest remembrances to your son, - - Believe me to be, my dear friend, ever truly yours, - - M. FARADAY. - - -This hope of explaining the variations of terrestrial magnetism by -the magnetic properties of the oxygen of the air was destined to be -illusory. At that time the cosmical nature of magnetic storms was -unknown and unsuspected. To this matter we may well apply Faraday’s own -words addressed to Tyndall respecting the alleged diamagnetic polarity, -and the conflict of views between himself on the one hand and Weber and -Tyndall on the other:--“It is not wonderful that views differ at first. -Time will gradually sift and shape them. And I believe that we have -little idea at present of the importance they may have ten or twenty -years hence.” - -[Sidenote: LINES OF MAGNETIC FORCE.] - -In 1851, from July to December, Faraday was actively at work in the -laboratory. The results constitute the material for the twenty-eighth -and twenty-ninth (the last) series of the “Experimental Researches.” -In these he returned to the subject with which the first series had -opened in 1831: the induction of electric currents by the relative -motion of magnets and conducting wires. These two memoirs, together -with his Royal Institution lecture of January, 1852, “On the Lines of -Magnetic Force,” and the paper “On the Physical Character of the Lines -of Magnetic Force” (which he sent to the _Philosophical Magazine_, as -containing “so much of a speculative and hypothetical nature”), should -be read, and re-read, and read again, by every student of physics. -They are reprinted at the end of the third volume of the “Experimental -Researches.” - -In the opening of the twenty-eighth memoir he says:-- - - From my earliest experiments on the relation of electricity and - magnetism, I have had to think and speak of lines of magnetic - force as representations of the magnetic power--not merely in - the points of quality and direction, but also in quantity.... - The direction of these lines about and amongst magnets and - electric currents is easily represented and understood in a - general manner by the ordinary use of iron filings. - - A point equally important to the definition of these lines - is, that they represent a determinate and unchanging amount - of force. Though, therefore, their forms, as they exist - between two or more centres or sources of power, may vary very - greatly, and also the space through which they may be traced, - yet the sum of power contained in any one section of a given - portion of the lines is exactly equal to the sum of power in - any other section[54] of the same lines, however altered in - form or however convergent or divergent they may be at the - second place.... Now, it appears to me that these lines may - be employed with great advantage to represent the nature, - condition, and comparative amount of the magnetic forces, - and that in many cases they have, to the physical reasoner, - at least, a superiority over that method which represents - the forces as concentrated in centres of action, such as the - poles of magnets or needles; or some other methods, as, for - instance, that which considers north or south magnetisms as - fluids diffused over the end, or amongst the particles, of a - bar. No doubt any of these methods which does not assume too - much will, with a faithful application, give true results. And - so they all ought to give the same results, as far as they can - respectively be applied. But some may, by their very nature, be - applicable to a far greater extent, and give far more varied - results, than others. For, just as either geometry or analysis - may be employed to solve correctly a particular problem, though - one has far more power and capability, generally speaking, than - the other; or, just as either the idea of the reflexion of - images or that of the reverberation of sounds may be used to - represent certain physical forces and conditions, so may the - idea of the attractions and repulsions of centres, or that of - the disposition of magnetic fluids, or that of lines of force, - be applied in the consideration of magnetic phenomena. It is - the occasional and more frequent use of the latter which I at - present wish to advocate.... When the natural truth, and the - conventional representation of it, most closely agree, then - are we most advanced in our knowledge. The emission and æther - theories present such cases in relation to light. The idea - of a fluid or of two fluids is the same for electricity; and - there the further idea of a current has been raised, which, - indeed, has such hold on the mind as occasionally to embarrass - the science as respects the true character of the physical - agencies, and may be doing so even now to a degree which we at - present little suspect. The same is the case with the idea of - a magnetic fluid or fluids, or with the assumption of magnetic - centres of action of which the resultants are at the poles. - - [Sidenote: THE FUNCTIONS OF THE ÆTHER.] - - How the magnetic force is transferred through bodies or through - space we know not--whether the result is merely action at a - distance, as in the case of gravity, or by some intermediate - agency, as in the cases of light, heat, the electric current, - and, as I believe, static electric action. The idea of magnetic - fluids, as applied by some, or of magnetic centres of action, - does not include that of the latter kind of transmission, - but the idea of lines of force does. Nevertheless, because a - particular method of representing the forces does not include - such a mode of transmission, the latter is not disproved, and - that method of representation which harmonises with it may be - the most true to nature. The general conclusion of philosophers - seems to be that such cases are by far the most numerous. And - for my own part, considering the relation of a vacuum to the - magnetic force, and the general character of magnetic phenomena - external to the magnet, I am more inclined to the notion that - in the transmission of the force there is such an action, - external to the magnet, than that the effects are merely - attraction and repulsion at a distance. _Such an action may be - a function of the æther, for it is not at all unlikely that if - there be an æther, it should have other uses than simply the - conveyance of radiations._[55] - -He then proceeds to recount the experimental evidence of revolving -magnets and loops of wire. Following out the old lines of so moving -the parts of the system that the magnetic lines were “cut” by the -copper conductors, and connecting the latter with a slow-period -galvanometer, to test the resultant induction, he found that “the -_amount_ of magnetic force” [or _flux_, as we should nowadays call it] -“is determinate for the same lines of force, whatever the distance of -the point or plane at which their power is exerted is from the magnet.” -The convergence or divergence of the lines of force caused, _per se_, -no difference in their amount. Obliquity of intersection caused no -difference, provided the same lines of force were cut. If a wire was -moving in a field of equal intensity, and with a uniform motion, then -the current produced was proportional to the velocity of motion. The -“quantity of electricity thrown into a current” was, _ceteris paribus_, -“directly as the amount of curves intersected.” Within the magnet, -running through its substance, existed lines of force of the _same -nature_ as those without, exactly equal in _amount_ to those without, -and were, indeed, _continuous_ with them. The conclusion must logically -be that every line of force is a closed circuit. - -Having thus established the exact quantitative laws of magneto-electric -induction, he then advanced to make use of the induced current as a -means of investigating the presence, direction, and amount of magnetic -forces--in other words, to explore and measure magnetic fields. He -constructed revolving rectangles and rings furnished with a simple -commutator, to measure inductively the magnetic forces of the earth. -Then he employed the induced current to test the constancy of magnets -when placed near to other magnets in ways that might affect their -power. Next he considers the fields of magnetic force of two or more -associated magnets, and notes how their magnetic lines may coalesce -when they are so placed as to constitute parts of a common magnetic -circuit. The twenty-ninth series is brought to a close by a discussion -of the experimental way of delineating lines of magnetic force by means -of iron filings. - -[Sidenote: THE ELECTROTONIC STATE.] - -The paper on the “Physical Character of the Lines of Magnetic Force” -recapitulated the points established in the twenty-ninth series of -“Researches,” and emphasis is laid upon the logical necessity that -time must be required for their propagation. The physical effects -in a magnetic field, as equivalent to a tendency for the magnetic -lines to shorten themselves, and to repel one another laterally, are -considered, and are contrasted with the effects of parallel electric -currents. Commenting on the mutual relation between the directions of -an electric current and of its surrounding magnetic lines, he raises -the question whether or not they consist in a state of tension of the -æther. “Again and again,” he says, “the idea of an _electrotonic_ state -has been forced on my mind. Such a state would coincide and become -identified with that which would then constitute the physical lines -of magnetic force.” Then he traces out the analogy between a magnet, -with its “sphondyloid” (or spindle-form field) of magnetic lines, and -a voltaic battery immersed in water, with its re-entrant lines of flow -of circulating current. Incidentally, while discussing the principle -of the magnetic circuit, he points out that when a magnet is furnished -at its poles with masses of soft iron, it can both receive and retain -a higher magnetic charge than it does without them, “for these masses -carry on the physical lines of force, and deliver them to a body of -surrounding space, which is either widened, and therefore increased, in -the direction across the lines of force, or shortened in that direction -parallel to them, or both; and both are circumstances which facilitate -the conduction from pole to pole.” - -[Sidenote: NOVELTY OF FARADAY’S VIEWS.] - -Thus closed, with the exception of two fragmentary papers, one on -“Physical Lines of Force,” and the other on “Some Points in Magnetic -Philosophy,” in the years 1853 and 1854 respectively, the main -life-work of Faraday, his “Experimental Researches.” Their effect -in revolutionising electric science, if slow, was yet sure. Though -the principle of the dynamo was discovered and published in 1831, -nearly forty years elapsed before electric-lighting machinery became -a commercial product. Though the dependence of inductive actions, -both electromagnetic and electrostatic, upon the properties of -the intervening medium was demonstrated and elaborated in these -“Researches,” electricians for many years continued to propound -theories which ignored this fundamental fact. French and German writers -continued to publish treatises based on the ancient doctrines of -action at a distance, and of imaginary electric and magnetic fluids. -Von Boltzmann, a typical German of the first rank in science, says -that until there came straight from England the counter-doctrines -amidst which Faraday had lived, “we (in Germany and France) had all -more or less imbibed with our mothers’ milk the ideas of magnetic -and electric fluids acting direct at a distance.” And again, “The -theory of Maxwell”--that is, Faraday’s theory thrown by Maxwell into -mathematical shape--“is so diametrically opposed to the ideas which -have become customary to us, that we must first cast behind us all our -previous views of the nature and operation of electric forces before -we can enter into its portals.” The divergence of view between Faraday -and the Continental electricians is nowhere more clearly stated than -by Faraday’s great interpreter, Maxwell, in the _apologia_ which he -prefixed in 1873 to his “Treatise on Electricity and Magnetism,” -wherein, speaking of the differences between this work and those -recently published in Germany, he wrote:-- - - One reason of this is that before I began the study of - electricity I resolved to read no mathematics on the subject - till I had first read through Faraday’s “Experimental - Researches on Electricity.” I was aware that there was supposed - to be a difference between Faraday’s way of conceiving - phenomena and that of the mathematicians. So that neither he - nor they were satisfied with each other’s language. I had also - the conviction that this discrepancy did not arise from either - party being wrong. I was first convinced of this by Sir William - Thomson [Lord Kelvin], to whose advice and assistance, as well - as to his published papers, I owe most of what I have learned - on this subject. - - As I proceeded with the study of Faraday, I perceived that his - method of conceiving the phenomena was also a mathematical one, - though not exhibited in the conventional form of mathematical - symbols. I also found that these methods were capable of being - expressed in the ordinary mathematical forms, and thus compared - with those of the professed mathematicians. - - For instance, Faraday, in his mind’s eye, saw lines of force - traversing all space where the mathematicians saw centres of - force attracting at a distance. Faraday saw a medium where - they saw nothing but distance. Faraday sought the seat of the - phenomena in real actions going on in the medium; they were - satisfied that they had found it in a power of action at a - distance impressed on electric fluids. - - When I had translated what I considered to be Faraday’s ideas - into a mathematical form, I found that in general the results - of the two methods coincided, so that the same phenomena were - accounted for and the same laws of action deduced by both - methods, but that Faraday’s methods resembled those in which - we begin with the whole and arrive at the parts by analysis, - while the ordinary mathematical methods were founded on the - principle of beginning with the parts and building up the whole - by synthesis. - - I found, also, that several of the most fertile methods of - research discovered by the mathematicians could be expressed - much better in terms of ideas derived from Faraday than in - their original form. - - The whole theory, for instance, of potential, considered as - a quantity which satisfies a certain partial differential - equation, belongs essentially to the method which I have called - of Faraday.... - - If by anything I have here written I may assist any student - in understanding Faraday’s modes of thought and expression, I - shall regard it as the accomplishment of one of my principal - aims: to communicate to others the same delight which I have - found myself in reading Faraday’s “Researches.” - -Clerk Maxwell may also be credited with the remark that Faraday’s work -had had the result of banishing the term “the electric fluid” into the -limbo of newspaper science. - -[Sidenote: ELECTRIC LIGHT IN LIGHTHOUSES.] - -Faraday’s work for Trinity House continued during these last years of -research work. He reported on such subjects as adulteration of white -lead, impure oils, Chance’s lenses, lighthouse ventilation, and fog -signals. Two systems of electric arc lighting for lighthouses--one by -Watson, using batteries, the other by Holmes, using a magneto-electric -machine--were examined in 1853 and 1854, but his report on them was -adverse. He “could not put up in a lighthouse what has not been -established beforehand, and is only experimental.” In 1856 he made five -reports, in 1857 six, and in 1858 twelve reports to Trinity House, -one of these being on the electric light at the South Foreland. In -1859 he reported on further trials in which Duboscq’s lamps were used. -In 1860 he gave a final report on the practicability and utility of -magneto-electric lighting, and expressed the hope it would be applied, -as there was _now_ no difficulty. In 1861 he inspected the machinery as -established at the Dungeness lighthouse. In 1862 he gave no fewer than -seventeen reports, visiting Dungeness, Grisnez, and the South Foreland. -In 1863 he again visited Dungeness. In 1864 he made twelve reports, and -examined the drawings and estimates for establishing the electric light -at Portland. His last report was in 1865, upon the St. Bees’ light, and -he then retired from this service. - -His Friday night discourses were still continued during these years. -In 1855 he gave one on “Ruhmkorff’s Induction-coil.” In 1856 he gave -one on a process for silvering glass, and on finely divided gold. This -latter subject, the optical properties of precipitated gold, formed -the topic of the Bakerian lecture of that year--his last contribution -to the Royal Society. He gave another discourse on the same subject -in 1857, and also one on the conservation of force. In 1856, when -investigating the crystallisation of water, he discovered the -phenomenon of regelation of ice. In virtue of this property two pieces -of ice will freeze solidly together under pressure, even when the -temperature of the surrounding atmosphere is above the freezing point. -This discovery led on the one hand to the explanation of glacier -motions; on the other to important results in thermodynamic theory. In -1859 he gave two discourses, one on ozone, the other on phosphorescence -and fluorescence. He also gave two in 1860, on lighthouse illumination -by electric light, and on the electric silk-loom. In 1861 he discoursed -on platinum and on De la Rue’s eclipse photographs. The last of his -Friday night discourses was given on June 20th, 1862. It was on -Siemens’s gas furnaces. He had been down at Swansea watching the -furnaces in operation, and now proposed to describe their principle. It -was rather a sad occasion, for it was but too evident that his powers -were fast waning. Early in the evening he had the misfortune to burn -the notes he had prepared, and became confused. He concluded with a -touching personal explanation how with advancing years his memory had -failed, and that in justice to others he felt it his duty to retire. - -At intervals he still attempted to work at research. In 1860 he sent a -paper to the Royal Society on the relations of electricity to gravity, -but, on the advice of Professor (afterwards Sir George) Stokes, it was -withdrawn. He had also in contemplation some experiments upon the time -required in the propagation of magnetism, and began the construction of -a complicated instrument, which was never finished. - -[Sidenote: HYPOTHESIS AND EXPERIMENT.] - -His very last experiment, as recorded in his laboratory notebook, is -of extraordinary interest, as showing how his mind was still at work -inquiring into the borderland of possible phenomena. It was on March -12th, 1862. He was inquiring into the effect of a magnetic field -upon a beam of light, which he was observing with a spectroscope to -ascertain whether there was any change produced in the refrangibility -of the light. The entry concludes: “Not the slightest effect on the -polarised or unpolarised ray was observed.” The experiment is of the -highest interest in magneto-optics. The effect for which Faraday -looked in vain in 1862 was discovered in 1897 by Zeeman. That Faraday -should have _conceived_ the existence of this obscure relation between -magnetism and light is a striking illustration of the acuteness of -mental vision which he brought to bear. Living and working amongst -the appliances of his laboratory, letting his thoughts play freely -around the phenomena, incessantly framing hypotheses to account for the -facts, and as incessantly testing his hypotheses by the touchstone of -experiment, never hesitating to push to their logical conclusion the -ideas suggested by experiment, however widely they might seem to lead -from the accepted modes of thought, he worked on with a scientific -prevision little short of miraculous. His experiments, even those which -at the time seemed unsuccessful, in that they yielded no positive -result, have proved to be a mine of amazing richness. The volumes -of his “Experimental Researches” are a veritable treasure-house of -science. - - - - -CHAPTER VI. - -MIDDLE AND LATER LIFE. - - -Although to avoid discontinuity the account of Faraday’s researches has -in the previous chapter been followed to their close in 1862, we must -now return to his middle period of life, when his activities at the -Royal Institution were at their zenith. - -[Sidenote: BREAKDOWN OF HEALTH.] - -Mention has been made of the serious breakdown of Faraday’s health at -the close of 1839. Dr. Latham, whom he consulted as to his attacks of -giddiness, wrote to Brande:-- - - Grosvenor Street, - December 1, 1839. - - DEAR BRANDE,--I have been seeing our friend Faraday these two - or three days, and been looking after his health. I trust he - has no ailment more than rest of body and mind will get rid - of. But rest is absolutely necessary for him. Indeed, I think - it would be hardly prudent for him to lecture again for the - present. He looks up to his work; but, in truth, he is not fit, - and if he is pressed he will suddenly break down. When we meet, - I will talk the matter over with you. - - Yours most sincerely, - P. M. LATHAM. - - -The advice was taken. He gave up nearly all research work, but tried -to go on with Friday night discourses and afternoon lectures in 1840. -Then came a more serious breakdown, and he rested for nearly four -years, with the exception of the Christmas lectures in 1841 and a few -Friday discourses in 1842 and 1843. This illness caused him great -distress of mind, mainly due to an idea that the physicians did not -understand his condition. When in this state he sometimes set down -pencil notes on scraps of paper to relieve his feelings. One such is -the following:-- - - Whereas, according to the declaration of that true man of - the world Talleyrand, the use of language is to conceal the - thoughts; this is to declare in the present instance, when I - say I am not able to bear much talking, it means really, and - without any mistake, or equivocation, or oblique meaning, or - implication, or subterfuge, or omission, that I am not able; - being at present rather weak in the head, and able to work no - more. - -During these times of enforced idleness he used to amuse himself with -games of skill, with paperwork, and with visits to the theatre and to -the Zoological Gardens. Mrs. Faraday left the following note:-- - - Michael was one of the earliest members of the Zoological - Society, and the Gardens were a great resource to him when - overwrought and distressed in the head. The animals were a - continual source of interest, and we, or rather I, used to - talk of the time when we should be able to afford a house - within _my_ walking distance of the entrance; for I much feared - he could not continue to live in the Institution with the - continual calls upon his time and thought; but he always shrank - from the notion of living away from the R. I. - -His niece, Miss Reid, told how fond he was of seeing acrobats, -tumblers, dwarfs and giants; even a Punch and Judy show was an -unfailing source of delight. When travelling in Switzerland, as he did -on several occasions, accompanied by Mrs. Faraday and her brother, -George Barnard, the artist, he kept a journal, which reveals his -simple pleasures and enthusiasms. He is delighted with waterfalls and -avalanches, watches the cowherd collecting his cows and the shepherd -calling the sheep, which followed him, leaving the goats to straggle. -On one such visit (in 1841), in order that he might not be absent on -Sunday from his wife, he walked the whole distance from Leukerbad -to Thun, over the Gemmi--a distance of 45 miles--in one day. At -Interlaken, observing that clout-nail-making was practised as a local -industry, he wrote: “I love a smith’s shop and everything relating to -smithery. My father was a smith.” - -[Sidenote: IMPRESSIONS OF LIEBIG.] - -In 1844 he was well enough to attend the British Association meeting at -York. Liebig, who had also been there, wrote to him three months later -with some reminiscences. What had struck him most was the tendency -in England to ignore the more purely scientific works and to value -only those with a “practical” bearing. “In Germany it is quite the -contrary. Here, in the eyes of scientific men, no value, or at least -but a trifling one, is placed on the practical results. The enrichment -of science is alone considered worthy of attention.” Liebig further -expressed himself dissatisfied with the meeting at York. He had been -interested to make the acquaintance of so many celebrated men, but it -was, strictly, “a feast given to the geologists, the other sciences -serving only to decorate the table.” Then came a more personal note:-- - - Often do my thoughts wander back to the period which I spent in - England, among the many pleasant hours of which the remembrance - of those passed with you and your amiable wife is to me always - the dearest and most agreeable. With the purest pleasure I - bring to mind my walk with her, in the botanical garden at - York, when I was afforded a glance of the richness of her mind; - what a rare treasure you possess in her! The breakfast in - the little house with Snow Harris, and Graham, and our being - together at Bishopthorpe, are still fresh in my memory. - -If Liebig was disposed to underrate the useful applications of science, -Faraday certainly was not. Though his own research work was carried -on with the single aim of scientific progress; though he himself -never swerved aside into any branch research that might have yielded -money; yet he was ever ready to examine, and even to lecture upon, -the inventions of others. He accepted for the subjects of his Friday -night discourses all sorts of topics--artificial stone, machinery for -pen-making, lithography, Ruhmkorff’s induction coil, a process for -silvering mirrors, and lighthouse illumination by electric light. His -very last lecture was on Siemens’s gas-furnaces. He could be just as -enthusiastic over the invention of another as over some discovery of -his own. With respect to his lecture on the Ruhmkorff coil, Tyndall -describes him in a passage which is interesting, as containing an -epithet since adopted for another great man for whom Tyndall had less -respect than for Faraday:-- - - I well remember the ecstasy and surprise of _the grand old - man_, evoked by effects which we should now deem utterly - insignificant. - -Bence Jones says:-- - - When he brought the discoveries of others before his hearers, - one object, and one alone, seemed to determine all he said and - did, and that was, “without commendation and without censure,” - to do the utmost that could be done for the discoverer. - -In so perfect a character it would be marvellous if there were not -some flaw. His persistent ignoring of Sturgeon, and his attribution -of the invention of the electromagnet to Moll and Henry, whose work -was frankly based on Sturgeon’s, is simply inexplicable. He failed to -appreciate the greatness of Dalton, and thought him an overrated man. - -[Sidenote: PERSONAL CHARACTERISTICS.] - -Amid all his overflowing kindliness of heart, Faraday preserved other -less obvious traits of character. Any act of injustice or meanness -called forth an almost volcanic burst of indignation. Hot flashes -of temper, fierce moments of wrath were by no means unknown. But he -exercised a most admirable self-control, and a habitual discipline -of soul that kept his temper under. Grim and forbidding, and even -exacting he could show himself to an idle or unfaithful servant. There -were those who feared as well as those who loved and admired him. -Dr. Gladstone says of him that he was no “model of all the virtues,” -dreadfully uninteresting, and discouraging to those who feel calm -perfection out of their reach. “His inner life was a battle, with its -wounds as well as its victory.” “It is true also,” he adds, “that -with his great caution and his repugnance to moral evil, he was more -disposed to turn away in disgust from an erring companion than to -endeavour to reclaim him.” - -For thirty years Faraday was the foremost of lecturers on science -in London. From the first occasion when, in 1823, as Sir Roderick -Murchison narrates, he was called upon unexpectedly to act as -substitute for Professor Brande at one of his morning lectures at the -Royal Institution (then held in the subterranean laboratory), down to -the time of his latest appearance as a lecturer in 1862, he was without -a rival as the exponent of natural science. - -As no man could achieve and retain such a position without possessing -both natural gifts and appropriate training, it is fitting to inquire -what were those gifts and what the training which were so happily -united in him. - - I was (he said) a very lively, imaginative person, and could - believe in the Arabian Nights as easily as in the Encyclopædia; - but facts were important to me, and saved me. I could trust a - fact, and always cross-examined an assertion. - -From the very first Faraday had an appreciation of the way in which -public lectures should be given. In his notes of Davy’s fourth lecture -of April, 1812, he wrote:-- - - During the whole of these observations his delivery was easy, - his diction elegant, his tone good, and his sentiments sublime. - -His own first lecture was given in the kitchen of Abbott’s house, with -home-made apparatus placed on the kitchen table. To Abbott, after -only a few weeks of experience at the Royal Institution, he wrote the -letters upon lectures and lecturers, to which allusion was made on p. -15. These show a most remarkably sound perception of the material and -mental furniture requisite for success. From the third and fourth of -them are culled the following excerpts:-- - -[Sidenote: QUALIFICATIONS OF A LECTURER.] - - The most prominent requisite to a lecturer, though perhaps - not really the most important, is a good delivery; for though - to all true philosophers science and nature will have charms - innumerable in every dress, yet I am sorry to say that the - generality of mankind cannot accompany us one short hour - unless the path is strewed with flowers. In order, therefore, - to gain the attention of an audience (and what can be more - disagreeable to a lecturer than the want of it?), it is - necessary to pay some attention to the manner of expression. - The utterance should not be rapid and hurried, and consequently - unintelligible, but slow and deliberate, conveying ideas with - ease from the lecturer, and infusing them with clearness and - readiness into the minds of the audience. A lecturer should - endeavour by all means to obtain a facility of utterance, and - the power of clothing his thoughts and ideas in language smooth - and harmonious, and at the same time simple and easy. - - With respect to the action of the lecturer, it is requisite - that he should have some, though it does not here bear the - importance that it does in other branches of oratory; for - though I know of no species of delivery (divinity excepted) - that requires less motion, yet I would by no means have a - lecturer glued to the table or screwed on the floor. He must - by all means appear as a body distinct and separate from the - things around him, and must have some motion apart from that - which they possess. - - A lecturer should appear easy and collected, undaunted and - unconcerned, his thoughts about him, and his mind clear and - free for the contemplation and description of his subject. His - action should not be hasty and violent, but slow, easy, and - natural, consisting principally in changes of the posture of - the body, in order to avoid the air of stiffness or sameness - that would otherwise be unavoidable. His whole behaviour - should evince respect for his audience, and he should in no - case forget that he is in their presence. No accident that - does not interfere with their convenience should disturb his - serenity, or cause variation in his behaviour; he should never, - if possible, turn his back on them, but should give them full - reason to believe that all his powers have been exerted for - their pleasure and instruction. - - Some lecturers choose to express their thoughts - extemporaneously immediately as they occur to the mind, whilst - others previously arrange them and draw them forth on paper. - But although I allow a lecturer to write out his matter, I do - not approve of his reading it--at least, not as he would a - quotation or extract. - - A lecturer should exert his utmost effort to gain completely - the mind and attention of his audience, and irresistibly to - make them join in his ideas to the end of the subject. He - should endeavour to raise their interest at the commencement - of the lecture, and by a series of imperceptible gradations, - unnoticed by the company, keep it alive as long as the subject - demands it. A flame should be lighted at the commencement, and - kept alive with unremitting splendour to the end. For this - reason I very much disapprove of breaks in a lecture, and where - they can by any means be avoided they should on no account find - place.... For the same reason--namely, that the audience should - not grow tired--I disapprove of long lectures; one hour is long - enough for anyone. Nor should they be allowed to exceed that - time. - - A lecturer falls deeply beneath the dignity of his character - when he descends so low as to angle for claps and asks for - commendation. Yet have I seen a lecturer even at this point. I - have heard him causelessly condemn his own powers. I have heard - him dwell for a length of time on the extreme care and niceness - that the experiment he will make requires. I have heard him - hope for indulgence when no indulgence was wanted, and I have - even heard him declare that the experiment now made cannot - fail, from its beauty, its correctness, and its application, - to gain the approbation of all.... I would wish apologies to - be made as seldom as possible, and generally only when the - inconvenience extends to the company. I have several times seen - the attention of by far the greater part of the audience called - to an error by the apology that followed it. - - ’Tis well, too, when the lecturer has the ready wit and - the presence of mind to turn any casual circumstance to an - illustration of his subject. Any particular circumstance that - has become table-talk for the town, any local advantages or - disadvantages, any trivial circumstance that may arise in - company, give great force to illustrations aptly drawn from - them, and please the audience highly, as they conceive they - perfectly understand them. - - Apt experiments (to which I have before referred) ought to - be explained by satisfactory theory, or otherwise we merely - patch an old coat with new cloth, and the whole [hole] becomes - worse. If a satisfactory theory can be given, it ought to be - given. If we doubt a received opinion, let us not leave the - doubt unnoticed and affirm our own ideas, but state it clearly, - and lay down also our objections. If the scientific world is - divided in opinion, state both sides of the question, and let - each one judge for himself by noticing the most striking and - forcible circumstances on each side. Then, and then only, shall - we do justice to the subject, please the audience, and satisfy - our honour, the honour of a philosopher. - -[Sidenote: USE OF CRITICISM.] - -One who already had set before himself such high ideals could not -fail at least to attempt to fulfil them. Accordingly, when in 1816 he -began to lecture to the City Philosophical Society, he began to attend -an evening class on elocution conducted by Mr. B. H. Smart, though -the pinch of poverty made it difficult to him to afford the needful -fees. Again, in 1823, previous to taking part in Brande’s laboratory -lectures, he took private lessons in elocution from Smart, at the -rate of half-a-guinea a lesson. After 1827, when he was beginning his -regular courses of lectures in the theatre, he often used to get Mr. -Smart to attend in order to criticise his delivery. - -Amongst the rules found in his manuscript notes were the following:-- - - Never to repeat a phrase. - - Never to go back to amend. - - If at a loss for a word, not to ch-ch-ch or eh-eh-eh, but to - stop and wait for it. It soon comes, and the bad habits are - broken and fluency soon acquired. - - Never doubt a correction given to me by another. - -His niece, Miss Reid, who lived from 1830 to 1840 at the Institution -with the Faradays, gave the following amongst her recollections:-- - - Mr. Magrath used to come regularly to the morning lectures, for - the sole purpose of noting down for him any faults of delivery - or defective pronunciation that could be detected. The list - was always received with thanks; although his corrections - were not uniformly adopted, he was encouraged to continue his - remarks with perfect freedom. In early days he always lectured - with a card before him with _Slow_ written upon it in distinct - characters. Sometimes he would overlook it and become too - rapid; in this case, Anderson had orders to place the card - before him. Sometimes he had the word _Time_ on a card brought - forward when the hour was nearly expired. - -[Sidenote: AS LECTURER.] - -In spite of his recourse to aids in acquiring elocutionary excellence, -his own style remained simple and unspoiled. “His manner,” says Bence -Jones, “was so natural, that the thought of any art in his lecturing -never occurred to anyone. For his Friday discourses, and for his -other set lectures in the theatre, he always made ample preparation -beforehand. His matter was always over-abundant. And, if his -experiments were always successful, this was not solely attributable -to his exceeding skill of hand. For, unrivalled as he was as a -manipulator, in the cases in which he attempted to show complicated -or difficult experiments, that which was to be shown was always well -rehearsed beforehand in the laboratory. He was exceedingly particular -about small and simple illustrations. He never merely _told_ his -hearers about an experiment, but _showed_ it to them, however simple -and well known it might be. To a young lecturer he once remarked: ‘If I -said to my audience, “This stone will fall to the ground if I open my -hand,” I should open my hand and let it fall. Take nothing for granted -as known; inform the eye at the same time as you address the ear.’ He -always endeavoured at the outset to put himself _en rapport_ with his -audience by introducing his subject on its most familiar side, and then -leading on to that which was less familiar. Before the audience became -aware of any transition, they were already assimilating new facts which -were thus brought within their range. Nor did he stay his discourse -upon the enunciation of facts merely. Almost invariably, as his -allotted hour drew towards its close, he gave rein to his imagination. -Those who had begun with him on the lower plane of simple facts and -their correlations were bidden to consider the wider bearings of -scientific principles and their relations to philosophy, to life, or to -ethics. While he never forced a peroration, nor dragged in a quotation -from the poets, his own scientific inspiration, as he outlined some -wide-sweeping speculation or suggestion for future discoveries, amply -supplied the fitting finale. If the rush of his ideas might sometimes -be compared to tearing through a jungle, it at least never degenerated -into sermonising; and never, save when he was physically ill, failed to -arouse an enthusiastic glow of response in his hearers. ‘No attentive -listener,’ says Mrs. Crosse, ‘ever came away from one of Faraday’s -lectures without having the limits of his spiritual vision enlarged, or -without feeling that his imagination had been stimulated to something -beyond the mere expression of physical facts.’” - -He was not one who let himself dwell in illusions. When he did well he -was perfectly conscious of the fact, and enjoyed a modest satisfaction. -If he had failed of his best, he was conscious too of that. His -deliberate act in giving up all other lectures at the time when his -brain-troubles were gaining upon him, while retaining the Christmas -lectures to juveniles, was thoroughly characteristic. Of one of his -earlier courses of lectures he himself made--about 1832--the following -note:-- - - The eight lectures on the operations of the laboratory at the - Royal Institution, April, 1828, were not to my mind. There - does not appear to be that opportunity of fixing the attention - of the audience by a single clear, consistent, and connected - chain of reasoning which occurs when a principle (_sic_) or - one particular application is made.... I do not think the - operations of the laboratory can be rendered useful and popular - in lectures.... - -The matter of these same lectures was, however, the basis of his book -on Chemical Manipulation published in 1827. It went through three -editions, and was reprinted in America. But in 1838 he declined to let -a new edition be issued, as he considered the work out of date. - -Besides the note quoted above from the Faraday MS. occurs the -following:-- - - The six juvenile lectures given Christmas, 1827, were just what - they ought to have been, both in matter and manner; but it - would not answer to give an extended course in the same spirit. - -Nineteen times did Faraday give the Christmas lectures. Those on the -Chemistry of a Candle were given more than once; and were the last he -gave, in 1860. They have been published, as were those on the Forces of -Nature. The lectures on Metals he was urged to publish, but declined in -the following terms:-- - - Royal Institution, January 3, 1859. - - DEAR SIR,--Many thanks to both you and Mr. Bentley. Mr. - Murray made me an unlimited offer like that of Mr. Bentley’s - many years ago, but for the reasons I am about to give you - I had to refuse his kindness. He proposed to take them by - shorthand, and so save me trouble, but I knew that would be a - thorough failure; even if I cared to give time to the revision - of the MS., still the lectures without the experiments and - the vivacity of speaking would fall far behind those in the - lecture-room as to effect. And then I do not desire to give - time to them, for money is no temptation to me. In fact, I have - always loved science more than money; and because my occupation - is almost entirely personal I cannot afford to get rich. Again - thanking you and Mr. Bentley, I remain, - - Very truly yours, - M. FARADAY. - - -[Sidenote: AN INSPIRED CHILD.] - -Of his lectures Lady Pollock wrote:-- - - He would play with his subject now and then, but very - delicately; his sport was only just enough to enliven the - attention. He never suffered an experiment to allure him away - from his theme. Every touch of his hand was a true illustration - of his argument.... But his meaning was sometimes beyond the - conception of those whom he addressed. When, however, he - lectured to children he was careful to be perfectly distinct, - and never allowed his ideas to outrun their intelligence. He - took great delight in talking to them, and easily won their - confidence. The vivacity of his manner and of his countenance, - and his pleasant laugh, the frankness of his whole bearing, - attracted them to him. They felt as if he belonged to them; and - indeed he sometimes, in his joyous enthusiasm, appeared like an - inspired child. - - ... His quick sympathies put him so closely in relation with - the child that he saw with the boy’s new wonder, and looked, - and most likely felt for the moment, as if he had never seen - the thing before. Quick feelings, quick movement, quick - thought, vividness of expression and of perception, belonged to - him. He came across you like a flash of light, and he seemed - to leave some of his light with you. His presence was always - stimulating.--_St. Paul’s Magazine_, June, 1870. - -A writer in the _British Quarterly Review_ says:-- - - He had the art of making philosophy charming, and this was due - in no little measure to the fact that to grey-headed wisdom he - united wonderful juvenility of spirit.... Hilariously boyish - upon occasion he could be, and those who knew him best knew - he was never more at home, that he never seemed so pleased, - as when making an old boy of himself, as he was wont to say, - lecturing before a juvenile audience at Christmas. - -Caroline Fox (in “Memories of Old Friends”), under date June 13th, -1851, wrote in her journal:-- - - We went to Faraday’s lecture on “Ozone.” He tried the various - methods of making ozone which Schönbein had already performed - in our kitchen, and he did them brilliantly. He was entirely at - his ease, both with his audience and his chemical apparatus. - -In the diary of H. Crabb Robinson is an appreciation of Faraday of some -interest:-- - - May 8th, 1840.... Attended Carlyle’s second lecture. It gave - great satisfaction, for it had uncommon thoughts and was - delivered with unusual animation.... In the evening heard a - lecture by Faraday. What a contrast to Carlyle! A perfect - experimentalist with an intellect so clear. Within his sphere - _un uomo compito_. - -Many references to Faraday’s lectures occur in the life of Sir Richard -Owen (published 1894), chiefly extracted from Mrs. Owen’s diary. Two or -three extracts must suffice:-- - - 1839, Jan. 8th. At eight o’clock with R. to the Royal - Institution to hear Faraday lecture on electricity, galvanism, - and the electric eel. Faraday is the _beau idéal_ of a popular - lecturer. - - 1845, Jan. 31. To Faraday’s lecture at the Royal Institution. - The largest crowd I have ever seen there. Many gentlemen were - obliged to come into the ladies’ gallery, as they could not - get seats elsewhere. After an exceedingly interesting lecture, - Faraday said he had a few remarks to make on some new reform - laws for the Institution. These remarks were admirably made, - and no one could feel offended, although it was a direct - attack on those gentlemen who helped to render the ladies very - uncomfortable, sometimes by filling seats, and often front - seats, in the part intended only for ladies. Wearing a hat in - the library was one of the delinquencies, likewise sitting in - the seats reserved for the directors, who were obliged by their - office and duties to be last in. Mr. Faraday also remarked - that the formation of two currents caused by certain gentlemen - rushing upstairs the instant the lecture was over to fetch - their lady friends was not conducive to the comfort of those - coming downstairs. Everything taken very well. - - [Sidenote: ROYAL INSTITUTION LECTURES.] - - 1849, May 28th. With R. to Royal Institution. We got there just - before three, and there was a crowded audience as usual to hear - Faraday’s lecture. The poor man entered and attempted to speak, - but he was suffering from inflammation or excessive irritation - of the larynx, and after some painful efforts to speak, a - general cry arose of “Postpone,” and someone, apparently in - authority, made a short speech from the gallery. Mr. Faraday - still wished to try and force his voice, saying he was well - aware of the difficulty of getting back the carriages, etc., - before the time for the lecture had elapsed, to say nothing of - the disappointment to some; but every moment the cry increased. - “No, no; you are too valuable to be allowed to injure yourself. - Postpone, postpone.” Poor Faraday was quite overcome. - -The interrupted lecture was resumed after a fortnight’s interval; and -he made up the full number of lectures by giving two extra discourses, -at one of which the Prince Consort was present. - - At another lecture [in 1856] Faraday explained the magnet and - strength of attraction. He made us all laugh heartily; and when - he threw a coalscuttle full of coals, a poker, and a pair of - tongs at the great magnet, and they stuck there, the theatre - echoed with shouts of laughter. - -His friend De la Rive testified in striking terms to Faraday’s power as -a speaker. - - Nothing can give a notion of the charm which he imparted to - these improvised lectures, in which he knew how to combine - animated, and often eloquent, language with a judgment and art - in his experiments which added to the clearness and elegance - of his exposition. He exerted an actual fascination upon his - auditors; and when, after having initiated them into the - mysteries of science, he terminated his lecture, as he was in - the habit of doing, by rising into regions far above matter, - space, and time, the emotion which he experienced did not fail - to communicate itself to those who listened to him, and their - enthusiasm had no longer any bounds. - -Faraday remained all his life a keen observer of other lecturers. -Visiting France in 1845, he went to hear Arago give an astronomical -lecture. “He delivered it in an admirable manner to a crowded -audience,” was his comment. - -To the Secretary of the Institution, who in 1846 consulted him -regarding evening lectures, he said: - - I see no objection to evening lectures if you can find a fit - man to give them. As to popular lectures (which at the same - time are to be _respectable_ and _sound_), none are more - difficult to find. Lectures which _really teach_ will never be - popular; lectures which are popular will never _really teach_. - They know little of the matter who think science is more - easily to be taught or learned than A B C; and yet who ever - learned his A B C without pain and trouble? Still, lectures can - (generally) inform the mind, and show forth to the attentive - man what he really has to learn, and in their way are very - useful, especially to the public. I think they might be useful - to us now, even if they only gave an answer to those who, - judging by their own earnest desire to learn, think much of - them. As to agricultural chemistry, it is no doubt an excellent - and a popular subject, but I rather suspect that those who know - least of it think that most is known about it. - -[Sidenote: USE OF MODELS AND CARDS.] - -His fondness for illustrating obscure points in his lectures by -models has been more than once alluded to. He would improvise these -out of wood, paper, wire, or even out of turnips or potatoes, with -much dexterity of hand. In one of his unpublished manuscripts, dating -about 1826, dealing with the then recently discovered phenomena of -electromagnetism, occurs the following note:-- - - It is best for illustration to have a model of the constant - position which the needle takes across the wire: _le voila_ - (Fig. 21). - - [Illustration: FIG. 21.] - -Many such simple models were used in his lectures. He leaned upon them -to aid his defective memory; but they helped his audience quite as much -as they aided him. Reference was made on p. 7 to his use of cards, on -which to jot down notes of thoughts that occurred to him. One such runs -as follows:-- - - Remember to do one thing at once. - - Also to finish a thing. - - Also to do a little if I could not do _much_. - - Pique about mathematics in chemists, and resolution to support - the character of experiment--as better for the mass. Hence - origin of the title _Exp. researches_. - - Influence of authority. Davy and difficulty of steering between - _self-sufficiency_ and dependance (_sic_) on others. - - Aim at high things, but not presumptuously. - - Endeavour to succeed--expect not to succeed. - - _Criticise_ one’s own view in every way by experiment--if - possible, leave no objection to be put by others. - -Faraday’s enthusiasm about experimental researches was at times -unrestrained, and always contagious. Dumas describes how Faraday -repeated for him the experimental demonstration of the action of -magnetism on light. Having come to the final experiment, Faraday -rubbed his hands excitedly, while his eyes lit up with fire, and his -animated countenance told the passionate feelings which he brought to -the discovery of scientific truth. On another occasion Plücker, of -Bonn, then on a visit to London, showed Faraday in his own laboratory -the action of a magnet upon the luminous electric discharge in vacuum -tubes. “Faraday danced round them; and as he saw the moving arches of -light, he cried: ‘Oh, to live always in it!’” Once a friend met him -at Eastbourne in the midst of a tremendous storm, rubbing his hands -together gleefully because he had been fortunate enough to see the -lightning strike the church tower. To the Baroness Burdett-Coutts -he once wrote inviting her to see some experiments upon spectrum -analysis in his private room. _The experiments_, he wrote, _will not be -beautiful except to the intelligent_. - -Yet another reminiscence is to be found in the Memorials of Joseph -Henry. It relates, probably, to the date of 1837, when Henry visited -Europe. - - Henry loved to dwell on the hours that he and Bache had spent - in Faraday’s society. I shall never forget Henry’s account of - his visit to King’s College, London, where Faraday, Wheatstone, - Daniell, and he had met to try and evolve the electric spark - from the thermopile. Each in turn attempted it and failed. - Then came Henry’s turn. He succeeded, calling in the aid of - his discovery of the effect of a long interpolar wire wrapped - around a piece of soft iron. Faraday became as wild as a boy, - and, jumping up, shouted: “Hurrah for the Yankee experiment!” - -The following memorandum was found on a slip of paper in Faraday’s -“research drawer”:-- - - THE FOUR DEGREES. - - The discoverer of a fact. - The reconciling of it to known principles. - Discovery of a fact not reconcilable. - He who refers all to still more general principles. - - M.F. - - -[Sidenote: FREEDOM OF SPECULATION.] - -Faraday’s mind was of a very individual turn; he could not walk -along the beaten tracks, but must pursue truth wherever it led him. -His dogged tenacity for exact fact was accompanied by a perfect -fearlessness of speculation. He would throw overboard without -hesitation the most deeply-rooted notions if experimental evidence -pointed to newer ideas. He had learned to doubt the idea of _poles_; -so he outgrew the idea of _atoms_, which he considered an arbitrary -conception. Many who heard his bold speculations and his free coinage -of new terms deemed him vague and loose in thought. Nothing could be -more untrue. He let his mind play freely about the facts; he framed -thousands of hypotheses, only to let them go by if they were not -supported by facts. “He is the wisest philosopher,” he said in a -lecture on the nature of matter, “who holds his theory with some -doubt--who is able to proportion his judgment and confidence to the -value of the evidence set before him, taking a fact for a fact and a -supposition for a supposition, as much as possible keeping his mind -free from all source of prejudice; or, where he cannot do this (as in -the case of a theory), remembering that such a source is there.” - -In one of his later experimental researches he wrote:-- - - As an experimentalist, I feel bound to let experiment guide me - into any train of thought which it may justify; being satisfied - that experiment, like analysis, must lead to strict truth if - rightly interpreted; and believing also that it is in its - nature far more suggestive of new trains of thought and new - conditions of natural power. - -[Sidenote: WHY NO SUCCESSOR.] - -Perhaps it was this very freedom of thought which debarred him from -enlisting other men as collaborators in his researches. His one -assistant for thirty years, Sergeant Anderson, was indeed invaluable -to him for his quality of implicit obedience. Other helpers in the -laboratory he had none. Apparently he found his researches to be of too -individual a character to permit him to deputise any part of his work. -He was never satisfied when told about another’s experiment; he must -perform it for himself. Often a discovery arose from some chance or -trivial incident of an otherwise unsuccessful experiment. The power of -“lateral vision,” which Tyndall has so strongly emphasised, was a prime -factor in his successes. That power could not be delegated to any mere -assistant. Many times did outsiders approach him, thinking to bring new -facts to his notice; never, save on the solitary occasion when a Mr. -William Jenkin drew his attention to the “extra-current” spark seen on -the breaking of an electric circuit, did such novelties turn out to -be really new. Alleged discoveries thus brought to him merely plagued -him. He thought that anyone who had the wit to observe any really new -phenomenon would be the person best qualified to work it out. His -method was to work on alone, dwelling amidst his experiments until the -mind, familiarising itself with the facts, was ready to suggest their -correlations. It was sometimes urged against him as a complaint that he -never took up any younger man to train him as his successor, even as -Davy had taken up himself and trained him in scientific work. One of -the miscellaneous notes, found after his death, throws some light on -this:-- - - It puzzles me greatly to know what makes the successful - philosopher. Is it industry and perseverance with a moderate - proportion of good sense and intelligence? Is not a modest - assurance or earnestness a requisite? Do not many fail because - they look rather to the renown to be acquired than to the pure - acquisition of knowledge, and the delight which the contented - mind has in acquiring it for its own sake? I am sure I have - seen many who would have been good and successful pursuers of - science, and have gained themselves a high name, but that it - was the name and the reward they were always looking forward - to--the reward of the world’s praise. In such there is always a - shade of envy or regret over their minds, and I cannot imagine - a man making discoveries in science under these feelings. As to - Genius and its power, there may be cases; I suppose there are. - I have looked long and often for a genius for our Laboratory, - but have never found one. But I have seen many who would, I - think, if they had submitted themselves to a sound self-applied - discipline of mind, have become successful experimental - Philosophers. - -To Dr. Becker he wrote: - - I was never able to make a fact my own without seeing it; and - the descriptions of the best works altogether failed to convey - to my mind such a knowledge of things as to allow myself to - form a judgment upon them. It was so with _new_ things. If - Grove, or Wheatstone, or Gassiot, or any other told me a new - fact, and wanted my opinion either of its value, or the cause, - or the evidence it could give on any subject, I never could say - anything until I had seen the fact. For the same reason I never - could work, as some Professors do most extensively, by students - or pupils. All the work had to be my own. - -[Sidenote: INCOME AND EXPENDITURE.] - -Of Faraday’s social life and surroundings during his meridional and -later period much might be written. After his great researches of 1831 -to 1836 scientific honours flowed in freely upon him, especially from -foreign academies and universities; and the fame he won at home would -have brought him, had he been so minded, an ample professional fortune -and all the artificial amenities of Society which follow the successful -money-maker. From all such mundane “success” he cut himself off when -in 1831 he decided to abandon professional fee-earning, and to devote -himself to the advancement of science. Probably the tenets of the -religious body to which he belonged were a leading factor in compelling -this decision. Not having laid upon him the necessity of providing -for a family, and accustomed to live in an unostentatious style, he -could contemplate the future without anxiety. With his pension, his -Woolwich lectures, and his Trinity House appointment, Faraday was in no -sense poor, though his Royal Institution professorship never brought -him so much as £300 a year until after he was over sixty years of age; -but on the other hand, his private charities were very numerous. How -much of his income was spent in that way can never be known; for the -very privacy of his deeds of kindness prevented any record from being -kept. Certain it is that his gifts to the aged poor and sick must have -amounted to several hundreds of pounds a year; for while his income -for many years must have averaged at least £1,000 or £1,100, and his -domestic expenditure could not have much exceeded half that sum, he -does not seem to have attempted to save anything. Nor did he grudge -time or strength to do kindly charitable acts in visiting the sick. - -From about the year 1834 he resolutely declined invitations to dinners -and such social gaieties; not, as some averred, from any religious -asceticism, but that he might the more unrestrainedly devote himself to -his researches. “If,” says Mrs. Crosse, “Babbage, Wheatstone, Grove, -Owen, Tyndall, and a host of other distinguished scientists, were to be -met very generally in the society of the day, there was one man who was -very conspicuous by his absence--this was Faraday! His biographers say -that in earlier years he occasionally accepted Lady Davy’s invitations -to dinner; but I never heard of his going anywhere, except in obedience -to the commands of royalty.” He did indeed occasionally dine quietly -with Sir Robert Peel or Earl Russell; and of the few public dinners he -attended, he enjoyed most the annual banquet of the Royal Academy of -Arts. - -Faraday does not, however, appear to have had any very direct relations -with the world of art. Once he was consulted by Lord John Russell -as to the removal of Raphael’s cartoons from Hampton Court to the -National Gallery. His advice was adverse, on account of the penetrating -power of dust. Though a sufficiently good draughtsman to prepare his -own drawings, he had little or no knowledge of the technicalities of -painting. Yet his sensitive and enthusiastic temperament had much in -common with that of the artist, and he enjoyed music, especially good -music, greatly. In early life he played the flute and knew many songs -by heart. He took bass parts in concerted singing, and is said to have -sung correctly in time and tune. In his circle of acquaintanceship -were numbered several painters of eminence--Turner, Landseer, and -Stanfield. His brother-in-law, Mr. George Barnard, the late well-known -water-colour artist, has written the following note:-- - - My first and many following sketching trips were made with - Faraday and his wife. Storms excited his admiration at all - times, and he was never tired of looking into the heavens. He - said to me once, “I wonder you artists don’t study the light - and colour in the sky more, and try more for effect.” I think - this quality in Turner’s drawings made him admire them so much. - He made Turner’s acquaintance at Hullmandel’s, and afterwards - often had applications from him for chemical information about - pigments. Faraday always impressed upon Turner and other - artists the great necessity there was to experiment for - themselves, putting washes and tints of all their pigments in - the bright sunlight, covering up one half, and noticing the - effect of light and gases on the other.... - - Faraday did not fish at all during these country trips, but - just rambled about geologising or botanising. - -[Sidenote: SCIENCE, LITERATURE, AND ART.] - -Earlier in his career, Faraday and his brother-in-law used to enjoy -conversaziones of artists, actors, and musicians at Hullmandel’s. -Sometimes they went up the river in Hullmandel’s eight-oar boat, -camping gipsy-wise on the banks for dinner, and enjoying the singing -of Signor Garcia and his wife and of his daughter, afterwards Madame -Malibran. From these things, too, he withdrew very largely when he -ceased to dine out, though he still liked to hear the opera and -to visit the theatre. Curiously enough, he seems to have had very -little in common with literary men. In the last half of the previous -century there had been many intimate relations between the leaders -of literature and those of science. The circle which included Watt, -Boulton, and Wedgwood included also Priestley and Erasmus Darwin. In -our own time the names of Darwin, Huxley, Hooker, and Tyndall are to -be found in conjunction with those of Tennyson, Browning, and Jowett. -But the biographies of literary men and artists of the period from 1830 -to 1850 bear few references to Faraday. He moved in his own world, and -that a world very much apart from literature or art. In his method of -working he was indeed an artist, often feeling his way rather than -calculating it, and arriving at his conclusions by what seemed insight -rather than by any direct process of reasoning. The discovery of -truth comes about in many ways; and if Faraday’s method in science -was artistic rather than scientific, it was amply justified by the -brilliant harvest of discoveries which it enabled him to reap. - -As is well known, Faraday never took out any patents for his -discoveries; indeed, whenever in his investigations he seemed to come -near to the point where they began to possess a marketable value -from their application to the industries, he left them, to pursue -his pioneering inquiries in other branches. He sought, indeed, for -principles rather than for processes, for facts new to science rather -than for merchantable inventions. When he had made the discovery -of magneto-electric induction--the basis of all modern electric -engineering--he carried the research to the point of constructing -several experimental machines, and then abruptly turned away with these -memorable words:-- - - I have rather, however, been desirous of discovering new facts - and new relations dependent on magneto-electric induction than - of exalting the force of those already obtained; being assured - that the latter would find their full development hereafter. - -[Sidenote: PRACTICAL UTILITIES.] - -Several times was Faraday known, when asked about the possible utility -of some new scientific discovery, to quote Franklin’s rejoinder: “What -is the use of a baby?” - -It is narrated of him that on one occasion, at a Trinity House dinner, -he and the Duke of Wellington had a little friendly chat, in the -course of which the Duke advised Faraday to give his speculations “a -practical turn as far as possible”--“a suggestion,” said Faraday, who -always spoke of the veteran with pleasure, “full of weight, coming -from such a man.” Faraday was, however, the last to despise the -importance of industrial applications of science. In his unpublished -manuscripts at the Royal Institution there are some curious references -to trials which he made of a meat-canning process, invented about -1848 by a Mr. Goldner, of Finsbury. He also had fancies for other -domestic applications, including wine-making. He used himself to -bind his own note-books. To a Mr. Woolnough, who had written a book -on the marbling of paper, he wrote a letter saying how much interest -he felt in the subject, “because of its associations with my early -occupation of bookbinding; and also because of the very beautiful -principles of natural philosophy which it involves.” He even, on one -occasion, produced a home-made pair of boots. His devotion to the -practical applications of science is attested by his untiring work for -improving the lighthouses of our coast. It is believed that his death -was accelerated by a severe cold caught when on a visit of lighthouse -inspection during stormy weather. - -Faraday was never ashamed of the circumstance of his having risen -from a humble origin. In his letters he not unfrequently alludes to -things that remind him of his bookbinding experiences, or of boyish -episodes in his father’s smithy. Yet he had none of the vulgar -pride of ascent which too often dogs the path of the self-made man. -Severe self-discipline and genuine humility prevented either undue -proclamation or awkward reticence respecting his early life. His elder -brother Robert was a gasfitter. Faraday was not ashamed to help him to -secure work in his trade, nor to give him the benefit of his scientific -aid in perfecting appliances for ventilating by gas-burners. The -following characteristic story was told by Frank Barnard:-- - - Robert was throughout life a warm friend and admirer of his - younger brother, and not a whit envious at seeing himself - passed in the social scale by him. One day he was sitting in - the Royal Institution just previous to a lecture by the young - and rising philosopher, when he heard a couple of gentlemen - behind him descanting on the natural gifts and rapid rise of - the lecturer. The brother--perhaps not fully apprehending the - purport of their talk--listened with growing indignation while - one of them dilated on the lowness of Faraday’s origin. “Why,” - said the speaker, “I believe he was a mere shoeblack at one - time.” Robert could endure this no longer; but turning sharply - round he demanded: “Pray, sir, did he ever black your shoes?” - “Oh! dear no, certainly not,” replied the gentleman, much - abashed at the sudden inquisition into the facts of the case. - -[Sidenote: SPIRIT MEDIUMS EXPOSED.] - -In 1853 Faraday came before the public in a novel manner--as the -exposer of the then rampant charlatanry of table-turning and -spirit-rapping. The _Athenæum_ for July 2nd contains a long letter -from him on table-turning. He experimentally investigated the alleged -phenomena as produced by three skilful mediums in _séances_ at the -house of a friend. His mechanical skill was more than a match, however, -for that of the supposed spirits. When the observers assembled around -the table placed their hands in the orthodox way upon the table-top, -the table turned, apparently without any effort on the part of any -one of the party. This was eminently satisfactory for the spirits. -But when Faraday interposed between each hand and the table-top a -simple roller-mechanism which, if any individual in the circle applied -muscular forces tending to turn it, instantly indicated the fact, the -table remained immovable. Faraday wrote merely describing the facts, -and saying that the test apparatus was now on public view at 122, -Regent Street. He ends thus:-- - - I must bring this long description to a close. I am a little - ashamed of it, for I think, in the present age, and in this - part of the world, it ought not to have been required. - Nevertheless, I hope it may be useful. There are many whom I - do not expect to convince; but I may be allowed to say that I - cannot undertake to answer such objections as may be made. I - state my own convictions as an experimental philosopher, and - find it no more necessary to enter into controversy on this - point than on any other in science, as the nature of matter, or - inertia, or the magnetisation of light, on which I may differ - from others. The world will decide sooner or later in all such - cases, and I have no doubt very soon and correctly in the - present instance. - -This exposure excited great interest at the time, and there was an -active correspondence in _The Times_. The spiritualists, instead of -appreciating the services to truth rendered by the man of science, -railed bitterly at him. Even the refined and noble spirit of Mrs. -Browning was so dominated by the superstition of the moment that, as -shown by her recently published letters, she denounced Faraday in -singularly acrimonious terms, and taunted him for shallow materialism! -What Faraday thought of the hubbub evoked by his action is best learned -from a letter which he addressed three weeks later to his friend -Schönbein:-- - - I have not been at work except in turning the tables upon - the table-turners, nor should I have done that, but that so - many inquiries poured in upon me, that I thought it better to - stop the inpouring flood by letting all know at once what my - views and thoughts were. What a weak, credulous, incredulous, - unbelieving, superstitious, bold, frightened, what a ridiculous - world ours is, as far as concerns the mind of man. How full - of inconsistencies, contradictions, and absurdities it is. - I declare that, taking the average of many minds that have - recently come before me (and apart from that spirit which God - has placed in each), and accepting for a moment that average - as a standard, I should far prefer the obedience, affections, - and instinct of a dog before it. Do not whisper this, however, - to others. There is One above who worketh in all things, and - who governs even in the midst of that misrule to which the - tendencies and powers of men are so easily perverted. - -He declined an invitation in 1855 to see manifestations by the medium -Home, saying that he had “lost too much time about such matters -already.” Nine years later the Brothers Davenport invited him to -witness their cabinet “manifestations.” Again he declined, and added: -“I will leave the spirits to find out for themselves how they can move -my attention. I am tired of them.” - -In this year he wrote to _The Times_ respecting the disgraceful and -insanitary condition of the river Thames. In _Punch_ of the following -week appeared a cartoon representing Faraday presenting his card to old -Father Thames, who rises holding his nose to avoid the stench. - -[Sidenote: FAILURE OF MEMORY.] - -With increasing age the infirmity of loss of memory made itself -increasingly felt. He alludes frequently to this in his letters. To -one friend who upbraided him gently for not having replied to a letter -he says: “Do you remember that I forget?” To another he says he is -forgetting how to spell such words as “withhold” and “successful.” To -Matteucci, in 1849, he bemoans how, after working for six weeks at -certain experiments, he found, on looking back to his notes, he had -ascertained all the same results eight or nine months before, and had -entirely forgotten them! In the same year he wrote to Dr. Percy:-- - - I cannot be on the Committee; I avoid everything of that kind, - that I may keep my stupid head a little clear. As to being on a - Committee and not working, that is worse still. - -In 1859, in a letter to his niece, Mrs. Deacon, filled mainly with -religious thoughts, he says: “My worldly faculties are slipping away -day by day. Happy is it for all of us that the true good lies not in -them.” - -From the journals of Walter White comes the following anecdote under -date December 22nd, 1858:-- - - Mr. Faraday called to enquire on the part of Sir Walter - Trevelyan whether a MS. of meteorological observations made - in Greenland would be acceptable. The question answered, I - expressed my pleasure at seeing him looking so well, and asked - him if he were writing a paper for the Royal. He shook his - head. “No: I am too old.” “Too old? Why, age brings wisdom.” - “Yes, but one may overshoot the wisdom.” “You cannot mean that - you have outlived your wisdom?” “Something like it, for my - memory is gone. If I make an experiment, I forget before twelve - hours are over whether the result was positive or negative; and - how can I write a paper while that is the case? No, I must - content myself with giving my lectures to children.” - -From another source we learn of a hitherto unrecorded incident which -happened to Mr. Joseph Newton, for some time an assistant in the Royal -Mint. While arranging some precious material on the Royal Institution -theatre lecture-table, previous to a lecture on the Mint and minting -operations by Professor Brande, Mr. Newton noticed an elderly, spare, -and very plainly-dressed individual watching his movements. Imagining -that this person was a superior messenger of the Institution, Mr. -Newton volunteered some information as to the coinage of gold. “I -suppose,” said the Mint employee, “you have been some years at the -Royal Institution?” “Well, yes, I have, a good many,” responded the -dilapidated one. “I hope they treat you pretty liberally--I mean, that -they give you a respectable ‘screw,’ for that is the main point.” “Ah! -I agree with you there. I think that the labourer is worthy of his -hire, and I shouldn’t mind being paid a little better.” Mr. Newton’s -surprise, on returning to the Royal Institution in the evening, to find -that the man whom he had so recently patronised was none other than -the illustrious but modest Michael Faraday can better be imagined than -described. - -A pretty instance, given on the authority of Lady Pollock, may be -recorded of the feeling aroused by Faraday’s presence when he returned -to his accustomed seat in the lecture-room of the Royal Institution, -after a protracted absence occasioned by illness:-- - - As soon as his presence was recognised, the whole audience - rose simultaneously and burst into a spontaneous utterance of - welcome, loud and long. Faraday stood in acknowledgment of this - enthusiastic greeting, with his fine head slightly bent; and - then a certain resemblance to the pictures and busts of Lord - Nelson, which was always observable in his countenance, was - very apparent. His hair had grown white and long, his face had - lengthened, and the agility of his movement was gone. The eyes - no longer flashed with the fire of the soul, but they still - radiated kindly thought; and ineffaceable lines of intellectual - force and energy were stamped upon his face. - -[Sidenote: HONOURS OFFERED AND DECLINED.] - -In 1857 he was offered the Presidency of the Royal Society. A painting -preserved in the rooms of the Royal Society records the scene when Lord -Wrottesley, Grove, and Gassiot waited upon him as a deputation from -the Council, to press on him his acceptance of the highest place which -science has to offer. He hesitated and finally declined, even as he -had declined the suggestion of knighthood years before. “Tyndall,” he -said in private to his successor, “I must remain plain Michael Faraday -to the last; and let me now tell you, that if I accepted the honour -which the Royal Society desires to confer upon me, I could not answer -for the integrity of my intellect for a single year.” He also declined -the Presidency of the Royal Institution, which he had served for fifty -years. His one desire was for rest. “The reverent affection of his -friends was,” said Tyndall, “to him infinitely more precious than all -the honours of official life.” - -Allusion has been made to Faraday’s tender and chivalrous regard -for his wife. Extracts from two letters, written in 1849 and 1863 -respectively, must here suffice to complete the story:-- - - Birmingham, Dr. Percy’s: - Thursday evening, September 13, 1849. - - MY DEAREST WIFE,--I have just left Dr. Percy’s hospitable - table to write to you, my beloved, telling you how I have been - getting on. I am very well, excepting a little faceache; and - very kindly treated here. They all long most earnestly for your - presence, for both Mrs. and Dr. Percy are anxious you should - come; and this I know, that the things we have seen would - delight you, but then I doubt your powers of running about as - we do; and though I know that if time were given you could - enjoy them, yet to press the matter into a day or two would - be a failure. Besides this, after all, there is no pleasure - like the tranquil pleasures of home, and here--even here--the - moment I leave the table, I wish I were with you IN QUIET. Oh! - what happiness is ours! My runs into the world in this way only - serve to make me esteem that happiness the more. I mean to be - at home on Saturday night, but it may be late first, so do not - be surprised at that; for if I can, I should like to go on an - excursion to the Dudley caverns, and that would take the day.... - - Write to me, dearest. I shall get your letter on Saturday - morning, or perhaps before. - - Love to father, Margery, and Jenny, and a thousand loves to - yourself, dearest, - - From your affectionate husband, - M. FARADAY. - - * * * * * - - 5, Claremont Gardens, Glasgow: - Monday, August 14, 1863. - - DEAREST,--Here is the fortnight complete since I left you and - the thoughts of my return to _our home_ crowd in strongly upon - my mind. Not that we are in any way uncared for, or left by - our dear friends, save as I may desire for our own retirement. - Everybody has overflowed with kindness, but you know their - manner, and their desire, by your own experience with me. I - long to see you, dearest, and to talk over things together, and - call to mind all the kindness I have received. My head is full, - and my heart also, but my recollection rapidly fails, even as - regards the friends that are in the room with me. You will have - to resume your old function of being a pillow to my mind, and a - rest, a happy-making wife. - - My love to my dear Mary. I expect to find you together, but do - not assume to know how things may be. - - Jeannie’s love with mine, and also Charlotte’s, and a great - many others which I cannot call to mind. - - Dearest, I long to see and be with you, whether together or - separate. - - Your husband, very affectionate, - M. FARADAY - - -[Sidenote: THE WIFE AND THE QUEEN.] - -In 1858 the Queen, at the suggestion of Prince Albert, who much -esteemed and valued Faraday’s genius, placed at his disposal for life -a comfortable house on the green near Hampton Court. Faraday’s only -hesitation in accepting the offer was a doubt whether he could afford -the needful repairs. On a hint of this reaching the Queen, she at once -directed that it should be put into thorough repair inside and out. He -still kept his rooms at the Royal Institution, and continued to live -there occasionally. - -With the increasing infirmities of age, his anxieties for his wife -seemed to be the only trouble that marred the serenity of his thought. -Lady Pollock’s narrative gives the following particulars:-- - - Sometimes he was depressed by the idea of his wife left without - kin--of the partner of his hopes and cares deprived of him. She - had been the first love of his ardent soul; she was the last; - she had been the brightest dream of his youth, and she was the - dearest comfort of his age; he never ceased for an instant to - feel himself happy with her; and he never for one hour ceased - to care for her happiness. It was no wonder, then, that he felt - anxiety about her. But he would rally from such a trouble with - his great religious trust, and looking at her with moist eyes, - he would say, “I must not be afraid; you will be cared for, my - wife; you will be cared for.” - - There are some who remember how tenderly he used to lead her to - her seat at the Royal Institution when she was suffering from - lameness; how carefully he used to support her; how watchfully - he used to attend all her steps. It did the heart good to see - his devotion, and to think what the man was and what he had - been. - -[Illustration: FIG. 22.--FARADAY’S HOME AT HAMPTON COURT.] - -[Sidenote: CLOSE OF SCIENTIFIC CAREER.] - -Gradually his powers waned. He gave his last juvenile lectures at -Christmas, 1860; and in October, 1861, being now seventy years of age, -he resigned his Professorship, while retaining the superintendence -of the laboratory. “Nothing,” he wrote to the managers, “would make -me happier in the things of this life than to make some scientific -discovery or development, and by that to justify the Board in their -desire to retain me in my position here.” His last research in the -laboratory was made on March 12, 1862. On June 20th he gave his last -Friday night discourse--on Siemens’s gas furnaces. He had, as his -notes show, already made up his mind to announce his retirement, and -the lecture was a sad and touching occasion, for the failure of his -powers was painfully evident. He continued for two years longer, and -with surprising activity, to work for Trinity House on the subject of -lighthouse illumination by the electric light. In 1865 he resigned -these duties to Dr. Tyndall. In 1864 he resigned his eldership in -the Sandemanian church. In March, 1865, he resigned the position of -superintendent of the house and laboratories of the Royal Institution. -He continued to attend the Friday evening meetings; but his tottering -condition of frame and mind was apparent to all. All through the winter -of 1865 and 1866 he became very feeble. Yet he took an interest in Mr. -Wilde’s description of his new magneto-electric machine. Almost the -last pleasure he showed on any scientific matter was when viewing the -long spark of a Holtz’s influence machine. He still enjoyed looking -at sunsets and storms. All through the summer and autumn of 1866 and -the spring of 1867 his physical powers waned. He was faithfully and -lovingly tended by his wife and his devoted niece, Jane Barnard. -He was scarcely able to move, but his mind “overflowed” with the -consciousness of the affectionate regard of those around him. He -gradually sank into torpor, saying nothing and taking little notice of -anything. Sitting in his chair in his study, he died peacefully and -painlessly on the 26th of August, 1867. On the 30th of August he was -quietly buried in Highgate Cemetery, his remains being committed to the -earth, in accordance with the custom of the religious body to which he -belonged, in perfect silence. None but personal friends were present, -the funeral being by his own verbal and written wishes strictly simple -and private. A simple unadorned tombstone marks the last resting-place -of Michael Faraday. - - - - -CHAPTER VII. - -VIEWS ON THE PURSUIT OF SCIENCE AND ON EDUCATION. - - -Between Faraday and the scientific men of his time there subsisted -many various relations. The influence which he exerted as a lecturer -and as an experimental investigator was unique; but, apart from -such influences, those relations were mainly confined to individual -friendships. With the organisation of science he had relatively very -little to do. We have seen how highly he prized the honour of admission -to the Fellowship of the Royal Society; and it remains to be told of -the gratification with which he accepted the scientific honours which -he received from almost every academy and university in Europe. Yet -he took little part in the work of scientific societies as such. Four -years after his election as F.R.S. he served on the Council, and he -remained on till 1831. He served again in 1833 and 1835. He was not, -however, satisfied with the management of the Royal Society, nor with -the way in which its Fellowship was at that time bestowed on men who -had no real claims on science, but were nominated through influence. -Echoes of this discontent are to be found in various pamphlets of the -day by Moll, Babbage, South, and others. Faraday, who edited Moll’s -pamphlet on the “Decline of Science,” is believed to have had an even -larger share in its production. In 1830 the really scientific men -amongst the Fellows desired to place Sir John Herschel as President; -the less scientific preferred the Duke of Sussex. Faraday took the -unusual step of speaking on the question, advocating the principle -that eminence in science should be the sole qualification for the -Presidency. At the same meeting Herschel moved, and Faraday seconded, -a plan for reforming the Council by nominating a list of fifty Fellows -from whose number the Council should be chosen. They carried their -plan, and Faraday’s name was amongst those so selected to serve. But -the presidential election went in favour of the Duke of Sussex by 119 -to 110 votes. After 1835 Faraday never served again on the Council. In -1843 he wrote to Matteucci:-- - - I think you are aware that I have not attended at the Royal - Society, either meetings or council, for some years. Ill health - is one reason, and another that I do not like the present - constitution of it, and want to restrict it to scientific men. - As these my opinions are not acceptable, I have withdrawn from - any management in it (still sending scientific communications - if I discover anything I think worthy). This, of course, - deprives me of power there. - -[Sidenote: REFORM IN THE ROYAL SOCIETY.] - -Two months earlier he wrote to Grove, who at that time was carrying out -the long-needed reforms, sympathising, but declining to co-operate:-- - - Royal Institution, - December 21, 1842. - - MY DEAR GROVE,--... As to the Royal Society, you know my - feeling towards it is for what it has been, and I hope may be. - Its present state is not wholesome. You are aware that I am - not on the council, and have not been for years, and have been - to no meeting there for years; but I do hope for better times. - I do not wonder at your feeling--all I meant to express was a - wish that its circumstances and character should improve, and - that it should again become a desirable reunion of _all_ really - scientific men. It has done much, is now doing much, in some - parts of science, as its magnetic observations show, and I hope - will some day become altogether healthy. - - Ever, my dear Grove, yours sincerely, - M. FARADAY. - - -Though he continued down to 1860 to send researches for publication -to the Royal Society, he seldom attended its meetings.[56] He was not -even present in November, 1845, on the occasion of the reading of his -paper on the action of the magnet on light. In 1857 he declined the -Presidency, though urged by the unanimous wish of the Council, as -narrated on p. 225. - -Though in the meridian of his active life, he took no part in the -founding of the British Association in 1831, but was at the Oxford -meeting in 1832, being one of the four scientific men (p. 65) selected -to receive the honorary degree of D.C.L. on that occasion. He also -communicated a paper on Electro-chemical Decomposition to the B.A. -meeting at Cambridge in 1833. He acted as president of the Chemical -Section of the Association in 1837 at Liverpool, and in 1846 at -Southampton; and he was chosen as vice-president of the Association -itself in the years 1844, at York (p. 224); 1849, at Birmingham (p. -256); and 1853, at Hull. He delivered evening discourses in 1847, -at Oxford, on Magnetic and Diamagnetic Phenomena; and in 1849, at -Birmingham, on Mr. Gassiot’s Battery. He also contributed to the -proceedings at the meetings at Ipswich in 1851 and at Liverpool in 1854. - -His comparative aloofness from scientific organisations arose probably -from the exceedingly individual nature of his own researches--to which -allusion was made on p. 242--rather than from any lack of sympathy. -He had no jealousy of co-operation in science. To Tyndall, then at -Marburg, he wrote in 1850 rejoicing at the circumstance that the work -on the magnetic properties of crystals was being taken up by others. -“It is wonderful,” he says, “how much good results from different -persons working at the same matter. Each one gives views and ideas new -to the rest. When science is a republic, then it gains; and though I am -no republican in other matters, I am in that.” Other causes there were, -doubtless, tending to his isolation, amongst them an old jealousy, now -long dead, against the Royal Institution on the part of some of the -Fellows of the Royal Society. Above all, probably, was his detestation -of controversy. - -[Sidenote: PRIORITY IN SCIENTIFIC DISCOVERY.] - -[Sidenote: PRIORITY IN PUBLICATION.] - -Priority in scientific discovery was a matter which deeply concerned -one whose life was devoted to scientific pioneering. To any question -as to scientific priority between himself and other workers he was -keenly sensitive. This was, indeed, natural in one who had voluntarily -relinquished fortune, and retired from lucrative professional work, -in the sole and single aim of advancing natural knowledge. His -single-minded and sensitive nature made him particularly scrupulous -in all such matters, and his early experiences must have added to the -almost excessive keenness of his perceptions. Having had in 1823, -when still merely assistant to Davy, to bear the double burden of a -serious misunderstanding with Dr. Wollaston as to the originality of -his discovery of the electro-magnetic rotations, and of a serious -estrangement from his master arising out of the liquid chlorine -discovery--an estrangement which threatened to cause his election to -the Royal Society to be indefinitely postponed--he was in later life -especially precise in dating and publishing his own researches. In -1831 there arose, concerning his great discovery of magneto-electric -induction, a curious misunderstanding. His discovery was, as we have -seen, made in September and October. He collected his results and -arranged them in the splendid memoir--the first in the series of -“Experimental Researches in Electricity”--which was read at the Royal -Society on November 24th. The _résumé_ of his work, which he wrote -five days later to Phillips, is given on pages 114–117. A fortnight -later he wrote a shorter and hasty letter in the same way to his -friend, M. Hachette of Paris--a letter which Faraday subsequently -well termed “unfortunate,” in view of the consequences that followed. -M. Hachette, a week later, communicated Faraday’s letter to the -Académie des Sciences on December 26th. It was published in _Le -Temps_ of December 28th. At that date the complete memoir read to -the Royal Society was not yet printed or circulated. The consequence -was that two Italian physicists, MM. Nobili and Antinori, seeing the -brief letter, and “considering that the subject was given to the -philosophical world for general pursuit,” immediately began researches -on magneto-electric induction in ignorance of Faraday’s full work. -Their results they embodied in a paper, in which they claimed to -have “verified, extended, and, perhaps, rectified the results of the -English philosopher,” accusing him of errors both in experiment and -theory, and even of a breach of good faith as to what he had said -about Arago’s rotations. This paper they dated January 31st, 1832; -but it was published in the belated number of the _Antologia_ for -November, 1831, where its appearance at an apparently earlier date -than Faraday’s original paper in the _Philosophical Transactions_ made -many Continental readers suppose that the researches of Nobili and -Antinori preceded those of Faraday. In June, 1832, Faraday published -in the _Philosophical Magazine_ a translation of Nobili’s memoir, with -his own annotations; and later in the year he wrote to Gay Lussac a -long letter on the errors of Nobili and Antinori. He showed how, in -spite of his efforts to clear up the misunderstanding, in spite of -his having sent several months previously to MM. Nobili and Antinori -copies of his original papers, no correction or retractation had -been made by them; and he concluded by a dignified protest that none -might say he had been too hasty to write that which might have been -avoided. It may be taken that the rule now recognised as to priority -of scientific publication--namely, that it dates from the day when the -discoverer communicates it formally to any of the recognised learned -societies--was virtually established by Faraday’s example. It will -be remembered that writing to De la Rive in 1845, to tell him of his -diamagnetic discoveries, he begged him to keep the matter secret, -adding: “I ought (in order to preserve the respect due to the Royal -Society) not to write a description to any one until the paper has -been received or even read there.” To younger men he inculcated the -necessity of proper and prompt publication of their researches if they -would reap the benefit of their work. To Sir William Crookes, then a -rising young chemist, he said: “Work, Finish, Publish.” Writing in 1853 -to Professor Matteucci, who had been annoyed with him for allowing -Du Bois Reymond, with whom Matteucci had had some controversy about -priority, to dedicate his book to him, Faraday says: “Who has not to -put up in his day with insinuations and misrepresentations in the -accounts of his proceedings given by others, bearing for the time the -present injustice, which is often unintentional, and often originates -in hasty temper, and committing his fame and character to the judgment -of the men of his own and future time?”... “I see that that moves -you which would move me most--namely, the imputation of a want of -good faith--and I cordially sympathise with any one who is so charged -unjustly. Such cases have seemed to me almost the only ones for which -it is worth while entering into controversy.”... “These polemics of the -scientific world are very unfortunate things; they form the great stain -to which the beautiful edifice of scientific truth is subject. _Are -they inevitable?_” - -Controversy whether in religion or science was to him alike detestable. -He took no part in politics. A letter to Tyndall (see “Faraday as a -Discoverer,” p. 39), written after the latter had told him of a rather -heated discussion at the British Association meeting in 1855, speaks of -his own efforts at forbearance. He says:-- - - These great meetings, of which I think very well altogether, - advance science chiefly by bringing scientific men together - and making them to know and be friends with each other; and I - am sorry when that is not the effect in every part of their - course.... The real truth never fails ultimately to appear.... - It is better to be blind to the results of partisanship, and - quick to see good will. One has more happiness in oneself in - endeavouring to follow the things that make for peace. You can - hardly imagine how often I have been heated in private when - opposed, as I have thought unjustly and superciliously, and yet - I have striven, and succeeded I hope, in keeping down replies - of the like kind. And I know I have never lost by it. - -[Sidenote: HATRED OF CONTROVERSY.] - -During the years when he was examining the apparatus of rival inventors -for lighthouse illumination, he could calmly hear them described as -Mr. So-and-So’s electric lights, all the while knowing that it was -his own discovery of magneto-electric induction which had made the -mechanical production of electric light possible. Yet he fired up if -anyone dared to revive the priority dispute between Davy and Stephenson -as to the invention of the safety lamp. “Disgraceful subject,” was -his own comment. In his dispute with Snow Harris as to the design of -lightning rods, in which, as it is now known, Snow Harris was right; -in his dispute with Airy over the curved lines of force; in his minor -difficulties over Hare’s pile and Becquerel’s magnetic observations, -none could either assert his own position with more simple dignity, nor -admit with greater frankness the rights of his rival. - -To Hare he wrote:-- - - You must excuse me, however, for several reasons from answering - it [Hare’s letter] at any length; the first is my distaste for - controversy, which is so great that I would on no account our - correspondence should acquire that character. I have often - seen it do great harm, and yet remember few cases in natural - knowledge where it has helped much either to pull down error or - advance truth. Criticism, on the other hand, is of much value. - -When we reflect how large a part of his experimental researches was -devoted to establishing the relations between the various forces of -nature, we cannot but think that Faraday must have regarded with -somewhat mixed feelings the publication in 1846 of Sir William Grove’s -volume on the Correlation of Forces. He had, in June, 1834, given a -course of lectures on the mutual relation of chemical and electrical -phenomena, and had dealt therein with the conversion of chemical and -electrical power into heat, and had speculated on the inclusion of -gravitation in these mutual relations. In 1853 Faraday marked the old -lecture notes of these lectures with his initials, and endorsed them -with the words “Correlation of Physical Forces.” Probably none rejoiced -more than he that Grove had undertaken the work of popularising the -notion which for a score of years had been familiar to himself. Yet -he was keen to resent an unjust reflection, as is shown by his letter -to Richard Phillips, republished in Vol. II. of the “Experimental -Researches,” p. 229, respecting Dr. John Davy’s Life of Sir Humphry. - -Faraday has himself left on record (p. 10) that when he wrote to Davy -asking to be taken into his employment, his motive was his desire “to -escape from trade, which I thought vicious and selfish, and to enter -into the service of Science, which, I imagined, made its pursuers -amiable and liberal.” Davy had smiled at this boyish notion, and had -told him that the experience of a few years would correct his ideas. -Years afterwards he spoke of this matter to Mrs. Andrew Crosse in an -interview which she has recorded:-- - - After viewing the ample appliances for experimental research, - and feeling much impressed by the scientific atmosphere of the - place, I turned and said, “Mr. Faraday, you must be very happy - in your position and with your pursuits, which elevate you - entirely out of the meaner aspects and lower aims of common - life.” - - He shook his head, and with that wonderful mobility of - countenance which was characteristic, his expression of - joyousness changed to one of profound sadness, and he replied: - “When I quitted business and took to science as a career, I - thought I had left behind me all the petty meannesses and small - jealousies which hinder man in his moral progress; but I found - myself raised into another sphere, only to find poor human - nature just the same everywhere--subject to the same weaknesses - and the same self-seeking, however exalted the intellect.” - - These were his words as well as I can recollect; and, looking - at that good and great man, I thought I had never seen a - countenance which so impressed me with the characteristic of - perfect unworldliness. - -[Sidenote: HONOURS AND TITLES.] - -Probably few men have ever been recipients of so many scientific -honours as Faraday. Beginning in the year 1823 with his election as a -corresponding member of the Académie des Sciences of Paris, and as an -honorary member of the Cambridge Philosophical Society, the list of -his diplomas and distinctions--some ninety-seven in number--ended in -1864 with his election as Associate of the Royal Academy of Sciences of -Naples. It included honours from almost every academy and university -of Europe. These honours Faraday valued very highly; and whilst he -consigned his various gold medals to a mere wooden box, his diplomas -were kept with the utmost care in a special diploma book, in which they -were mounted and indexed. To Mr. Spring Rice, who in 1838 asked him for -a list of his titles, he replied, enclosing the list, and adding this -remark: “One title, namely that of F.R.S., was sought and paid for; -all the rest are spontaneous offerings of kindness and goodwill from -the bodies named.” Years afterwards he was asked by Lord Wrottesley -to advise the Government as to how the position of science or of the -cultivators of science in England might be improved. The letter is so -characteristic that it cannot be spared:-- - - Royal Institution: March 10, 1854. - - MY LORD,--I feel unfit to give a deliberate opinion on the - course it might be advisable for the Government to pursue - if it were anxious to improve the position of science and - its cultivators in our country. My course of life, and the - circumstances which make it a happy one for me, are not those - of persons who conform to the usages and habits of society. - Through the kindness of all, from my Sovereign downwards, - I have that which supplies all my need; and in respect of - honours, I have, as a scientific man, received from foreign - countries and sovereigns those which, belonging to very limited - and select classes, surpass in my opinion anything that it is - in the power of my own to bestow. - - I cannot say that I have not valued such distinctions; on the - contrary, I esteem them very highly, but I do not think I have - ever worked for or sought after them. Even were such to be now - created here, the time is past when these would possess any - attraction for me.... - - Without thinking of the effect it might have upon distinguished - men of science, or upon the minds of those who, stimulated - to exertion, might become distinguished, I do think that a - government should, _for its own sake_, honour the men who do - honour and service to the country. I refer now to honours only, - not to beneficial rewards. Of such honours, I think, there - are none. Knighthoods and baronetcies are sometimes conferred - with such intentions, but I think them utterly unfit for that - purpose. Instead of conferring distinction, they confound the - man who is one of twenty, or perhaps fifty, with hundreds of - others. They depress rather than exalt him, for they tend to - lower the especial distinction of mind to the commonplace - of society. An intelligent country ought to recognise the - scientific men amongst its people as a class. If honours are - conferred upon eminence in any class, as that of the law or - the army, they should be in this also. The aristocracy of - the class should have other distinctions than those of lowly - and high-born, rich and poor, yet they should be such as to - be worthy of those whom the sovereign and the country should - delight to honour; and, being rendered very desirable, and even - enviable, in the eyes of the aristocracy by birth, should be - unattainable except to that of science. Thus much, I think, - the Government and the country ought to do, for their own sake - and the good of science, more than for the sake of the men who - might be thought worthy of such distinction. The latter have - attained to their fit place, whether the community at large - recognise it or not.... - - I have the honour to be, my lord, your very faithful servant, - - M. FARADAY. - - -[Sidenote: HOW SCIENCE CAN BE HONOURED.] - -To Professor Andrews he wrote in 1843 in a similar strain:-- - - I have always felt that there is something degrading in - offering rewards for intellectual exertion, and that societies - or academies, or even kings and emperors, should mingle in the - matter does not remove the degradation, for the feeling which - is hurt is a point above their condition, and belongs to the - respect which a man owes to himself.... Still, I think rewards - and honours _good_ if properly distributed; but they should be - given for what a man has done, and not offered for what he is - to do. - -When a friend wrote to him on hearing a rumour that he had himself been -knighted, his reply, published years after in the _London Review_, was: -“I am happy that I am not a Sir, and do not intend (if it depends upon -me) to become one. By the Prussian knighthood[57] I do feel honoured; -in the other I should not.” - -On one occasion he commented rather sarcastically upon the British -Government and its stinginess as compared with those of all other -civilised countries in its aids to scientific progress. This complaint -is equally justified to-day. To many it may be news that England pays -to its Astronomer Royal--who must obviously be a person of very high -scientific qualifications--a salary less than those paid to the five -assistant under-secretaries in the Colonial and Foreign Offices; less -than that paid to the sergeants-at-arms in the Houses of Parliament; -less than that paid to the person appointed Director of Clothing in the -War Office. Enlightened England! - -Faraday did not deem the pursuit of science to be necessarily -incompatible with what he termed “professional business”--that -is, expert work. Until the day when he abandoned all professional -engagements, so as to devote himself to researches, he had been -receiving a considerable and growing income from this source. But -he objected to the indignities to which this work exposed him from -lawyers, who would not understand that he took no partisan view. He -could not endure the browbeating of cross-examining counsel. The late -Lord Cardwell was witness to a gentle but crushing reproof which he -once administered to a barrister who attempted to bully him. A writer -in the _British Quarterly Review_ attributes to a specific case his -determination to cease expert work. - - He gave evidence once in a judicial case, when the scientific - testimony, starting from given premises, was so diverse that - the presiding judge, in summing up launched something like a - reproach at the scientific witnesses. “Science has not shone - this day,” was his lordship’s remark. From that time forth - no one ever saw Faraday as a scientific witness before a law - tribunal. - -[Sidenote: UNIVERSITY DEGREES IN SCIENCE.] - -Amongst the honours received by Faraday there was one of which, -in 1838, he said that he felt it equal to any other he had -received--namely, that of Member of the Senate of the University of -London, to which position he was nominated in 1836 by the Crown. For -twenty-seven years he remained a senator, and when, in 1859, the -project for creating degrees in science was on foot, he was one of -the committee who drew up a report and scheme of examination for the -Senate. To the Rev. John Barlow he wrote on this matter:-- - - The Senate of the University accepted and approved of the - report of the Committee for Scientific Degrees, so that that - will go forward (if the Government approve), and will come into - work next year. It seems to give much satisfaction to all who - have seen it, though the subject is beset with difficulties; - for when the depth and breadth of science came to be - considered, and an estimate was made of how much a man ought to - know to obtain a right to a degree in it, the amount in words - seemed to be so enormous as to make me hesitate in demanding it - from the student; and though in the D.S. one could divide the - matter and claim eminence in one branch of science, rather than - good general knowledge in all, still in the B.S., which is a - progressive degree, a more extended though a more superficial - acquaintance seemed to be required. In fact, the matter is - so new, and there is so little that can serve as a previous - experience in the founding and arranging these degrees, that - one must leave the whole endeavour to shape itself as the - practice and experience accumulates. - -When, in 1863, his feebleness impelled him to resign this position, he -wrote to Dr. Carpenter:-- - - The position of a senator is one that should not be held by - an inactive man to the exclusion of an active one. It has - rejoiced my heart to see the progress of the University, and - of education under its influence and power; and that delight I - hope to have so long as life shall be spared to me. - -He had little sympathy with either text-book science or with mere -examinations. “I have far more confidence,” he wrote, “in the one man -who works mentally and bodily at a matter than in the six who merely -talk about it. Nothing is so good as an experiment which, whilst -it sets error right, gives an absolute advancement in knowledge.” -In another place he wrote:--“Let the imagination go, guarding it -by judgment and principles, but holding it in and directing it by -experiment.” For book-learned chemistry and mere chemical theory, apart -from experimental facts, he had an undisguised contempt. Writing to -General Portlock on the subject of chemical education, he stated that -he had been one of the Senate of the University of London appointed to -consider especially the best method of examination. They had decided -on examination by papers, accompanied by _vivâ voce_. “We think,” he -added, “that no numerical value can be attached to the questions, -because everything depends on _how they are answered_.” Then, referring -to the teaching at Woolwich, he says, “My instructions always have -been to look to the note-books for the result.” “Lectures alone cannot -be expected to give more than a general idea of this most extensive -branch of science, and it would be too much to expect that young men -who at the utmost hear only fifty lectures on chemistry should be -able to answer with much effect, in writing, to questions set down on -paper, when we know by experience that daily work for eight hours in -_practical laboratories_ for _three months_ does not go very far to -confer such ability.” - -[Sidenote: SCIENCE AND THE UNIVERSITIES.] - -He had, at an earlier date, declined to be appointed as examiner in the -University. He had previously declined the professorship of chemistry -in University College; and he had also declined the chemical chair in -the University of Edinburgh. This was not, however, from any want of -sympathy with university work, or failure to appreciate the ideal of a -university as a seat of learning. Writing to Tyndall, in 1851, about -another university--that at Toronto--he said: “I trust it is a place -where a man of science and a true philosopher is required, and where, -in return, such a man would be nourished and cherished in proportion to -his desire to advance natural knowledge.” - -At the same time he had an exceeding repugnance to the custom of -expecting candidates for professorial chairs to produce “testimonials” -of their qualifications. When his intimate friend Richard Phillips was -a candidate for the very chair which Faraday refused at University -College, Faraday declined on principle to give a testimonial. “I should -indeed have thought,” he added, “his character had been known to -be such that it would rather have been degraded than established by -certificates.” - -Similarly, in 1851, he told Tyndall, then an applicant for the Chair of -Physics at Toronto, that he had in every case refused for many years -past to give any on the application of candidates. “Nevertheless,” he -added, “I wish to say that when I am asked about a candidate by those -who have the choice or appointment, I never refuse to answer.” - -[Sidenote: SCIENCE IN EDUCATION.] - -On general education, Faraday’s ideas were much in advance of his -time. From the epoch when as a young man he lectured to the City -Philosophical Society on the means of obtaining knowledge and on mental -inertia, down to the close of his career, he consistently advocated -the cultivation of the experimental method and the use of science as -a means of training the faculties. A concise account of his views is -to be found in the lecture he gave in 1854 before the Prince Consort -on “Mental Education,” a lecture which prescribes the self-educating -discipline of scientific study and experiment as a means of correcting -deficiency of judgment. It included a powerful plea for suspense of -judgment and for the cultivation of the faculty of proportionate -judgment. In 1862 he was examined at some length by the Royal -Commissioners upon Public Schools. With them he pleaded strongly for -the introduction of science into the school curricula; and when asked -at what age it might be serviceable to introduce science-teaching, -replied: “I think one can hardly tell that until after experience for -some few years. All I can say is this that at my juvenile lectures at -Christmas time I have never found a child too young to understand -intelligently what I told him; they came to me afterwards with -questions which proved their capability.” - -One passage from the close of a lecture given in 1858 deserves to be -recorded for its fine appreciation of “the kind of education which -science offers to man”:-- - - It teaches us to be neglectful of nothing, not to despise - the _small_ beginnings--they precede of necessity _all great - things_.... It teaches a continual comparison of the _small - and great_, and that under differences almost approaching - the infinite, for the small as often contains the great in - principle as the great does the small; and thus the mind - becomes comprehensive. It teaches to deduce principles - carefully, to hold them firmly, or to suspend the judgment, - to discover and obey _law_, and by it to be bold in applying - to the greatest what we know of the smallest. It teaches us, - first by tutors and books, to learn that which is already known - to others, and then by the light and methods which belong to - science to learn for ourselves and for others; so making a - fruitful return to man in the future for that which we have - obtained from the men of the past. Bacon in his instruction - tells us that the scientific student ought not to be as the - ant, who gathers merely, nor as the spider who spins from her - own bowels, but rather as the bee who both gathers and produces. - - All this is true of the teaching afforded by any part of - physical science. Electricity is often called wonderful, - beautiful; but it is so only in common with the other forces of - nature. The beauty of electricity or of any other force is not - that the power is mysterious, and unexpected, touching every - sense at unawares in turn, but that it is under _law_, and that - the taught intellect can even now govern it largely. The human - mind is placed above, and not beneath it, and it is in such a - point of view that the mental education afforded by science is - rendered super-eminent in dignity, in practical application and - utility; for by enabling the mind to apply the natural power - through law, it conveys the gifts of God to man. - -[Sidenote: ON MATHEMATICS.] - -A peculiar interest attaches to Faraday’s attitude towards the study -of mathematics. He who had never had any schooling beyond the common -school of his parish had not advanced beyond the simplest algebra in -his mastery over symbolic reasoning. Several times in his “Experimental -Researches” he deplores what he termed “my imperfect mathematical -knowledge.” Of Poisson’s theory of magnetism he said: “I am quite unfit -to form a judgment.” Dr. Scoffern repeats a pleasantry of Faraday’s -having on a certain occasion boasted that he had once in the course of -his life performed a mathematical operation--when he turned the handle -of Babbage’s calculating machine. Certain it is that he went through -the whole of his magnificent researches without once using even a sine -or a cosine, or anything more recondite than the simple rule-of-three. -He expressed the same kind of regret at his unfamiliarity with the -German language--“the language of science and knowledge,” as he -termed it in writing to Du Bois Reymond--which prevented him from -reading the works of Professor “Ohms.” Nevertheless he valued the -mathematical powers of others, and counselled Tyndall to work out his -experimental results, “so that the mathematicians may be able to take -it up.” Yet he never relaxed his preference for proceeding along the -lines of experimental investigation. His curious phrase (p. 239) as -to his pique respecting mathematics is very significant, as is also -his note of jubilation in his letter to Phillips (p. 117) at finding -that pure experiment can successfully rival mathematics in unravelling -the mysteries which had eluded the efforts of Poisson and Arago. -He himself attributed to his defective memory his want of hold upon -symbolic reasoning. To Tyndall he wrote in 1851, when thanking him for -a copy of one of his scientific memoirs:-- - - Such papers as yours make me feel more than ever the loss of - memory I have sustained, for there is no reading them, or at - least retaining the argument, under such deficiency. - - Mathematical formulæ more than anything require quickness and - surety in receiving and retaining the true value of the symbols - used; and when one has to look back at every moment to the - beginning of a paper, to see what H or A or B mean, there is - no making way. Still, though I cannot hold the whole train of - reasoning in my mind at once, I am able fully to appreciate - the value of the results you arrive at, and it appears to me - that they are exceedingly well established and of very great - consequence. These elementary laws of action are of so much - consequence in the development of the nature of a power which, - like magnetism, is as yet new to us. - -Again to Clerk Maxwell, in 1857, he wrote:-- - - There is one thing I would be glad to ask you. When a - mathematician engaged in investigating physical actions and - results has arrived at his own conclusions, may they not be - expressed in common language as fully, clearly, and definitely - as in mathematical formulæ? If so, would it not be a great boon - to such as we to express them so--translating them out of their - hieroglyphics that we also might work upon them by experiment? - I think it must be so, because I have always found that you - could convey to me a perfectly clear idea of your conclusions, - which, though they may give me no full understanding of the - steps of your process, gave me the results neither above nor - below the truth, and so clear in character that I can think and - work from them. - - If this be possible, would it not be a good thing if - mathematicians, writing on these subjects, were to give us - their results in this popular useful working state as well as - in that which is their own and proper to them? - -The achievement of Faraday in finding for the expression of -electromagnetic laws means which, though not symbolic, were simple, -accurate, and in advance of the mathematics of his time, has been -alluded to on page 217. Liebig, in his discourse on “Induction and -Deduction,” refers to Faraday thus:-- - - I have heard mathematical physicists deplore that Faraday’s - records of his labours were difficult to read and understand, - that they often resembled rather abstracts from a diary. But - the fault was theirs, not Faraday’s. To physicists who have - approached physics by the road of chemistry, Faraday’s memoirs - sound like an admirably beautiful music. - -[Sidenote: MAXWELL AND VON HELMHOLTZ.] - -Von Helmholtz, in his Faraday lecture of 1881, has also touched on this -aspect. - - Now that the mathematical interpretation of Faraday’s - conceptions regarding the nature of electric and magnetic - forces has been given by Clerk Maxwell, we see how great a - degree of exactness and precision was really hidden behind the - words which to Faraday’s contemporaries appeared either vague - or obscure; and it is in the highest degree astonishing to - see what a large number of general theorems, the methodical - deduction of which requires the highest powers of mathematical - analysis, he found by a kind of intuition, with the security of - instinct, without the help of a single mathematical formula. - -Two other passages from Von Helmholtz are worthy of being added:-- - - And now, with a quite wonderful sagacity and intellectual - precision, Faraday performed in his brain the work of a great - mathematician without using a single mathematical formula. - He saw with his mind’s eye that magnetised and dielectric - bodies ought to have a tendency to contract in the direction - of the lines of force, and to dilate in all directions - perpendicular to the former, and that by these systems of - tensions and pressures in the space which surrounds electrified - bodies, magnets, or wires conducting electric currents, all - the phenomena of electrostatic, magnetic, electromagnetic - attraction, repulsion, and induction could be explained, - without recurring at all to forces acting directly at a - distance. This was the part of his path where so few could - follow him; perhaps a Clerk Maxwell, a second man of the same - power and independence of intellect, was needed to reconstruct - in the normal methods of science the great building the plan of - which Faraday had conceived in his mind, and attempted to make - visible to his contemporaries. - - Nobody can deny that this new theory of electricity and - magnetism, originated by Faraday and developed by Maxwell, is - in itself well consistent, in perfect and exact harmony with - all the known facts of experience, and does not contradict any - one of the general axioms of dynamics, which have been hitherto - considered as the fundamental truths of all natural science, - because they have been found valid, without any exception, in - all known processes of nature. - -And, after dealing with the phenomena discussed by Faraday, Von -Helmholtz adds these pregnant words:-- - - Nevertheless, the fundamental conceptions by which Faraday - was led to these much-admired discoveries have not received - an equal amount of consideration. They were very divergent - from the trodden path of scientific theory, and appeared - rather startling to his contemporaries. His principal aim was - to express in his new conceptions only facts, with the least - possible use of hypothetical substances and forces. This was - really an advance in general scientific method, destined to - purify science from the last remnants of metaphysics. Faraday - was not the first, and not the only man, who had worked in - this direction, but perhaps nobody else at his time did it so - radically. - -Clerk Maxwell said of him: - - The way in which Faraday made use of his lines of force in - co-ordinating the phenomena of electric induction shows him to - have been a mathematician of high order, and one from whom the - mathematicians of the future may derive valuable and fertile - methods. - -It is fitting to include in this review of Faraday’s place in relation -to the mathematical side of physics some words of Lord Kelvin, taken -from his preface to the English edition of Hertz’s “Electric Waves”:-- - - Faraday, with his curved lines of electric force, and - his dielectric efficiency of air and of liquid and solid - insulators, resuscitated the idea of a medium through which, - and not only through which but _by_ which, forces of attraction - or repulsion, seemingly acting at a distance, are transmitted. - - The long struggle of the first half of the eighteenth century - was not merely on the question of a medium to serve for - gravific mechanism, but on the correctness of the Newtonian - law of gravitation as a matter of fact, however explained. The - corresponding controversy in the nineteenth century was very - short, and it soon became obvious that Faraday’s idea of the - transmission of electric force by a medium not only did not - violate Coulomb’s law of relation between force and distance, - but that, if real, it must give a thorough explanation of that - law. Nevertheless, after Faraday’s discovery of the different - specific inductive capacities of different insulators, twenty - years passed before it was generally accepted in Continental - Europe. But before his death, in 1867, he had succeeded in - inspiring the rising generation of the scientific world - with something approaching to faith that electric force is - transmitted by a medium called ether, of which, as had been - believed by the whole scientific world for forty years, light - and radiant heat are transverse vibrations. Faraday himself - did not rest with this theory of electricity alone. The very - last time I saw him at work at the Royal Institution was in - an underground cellar, which he had chosen for freedom from - disturbance, and he was arranging experiments to test the - time of propagation of magnetic force from an electromagnet - through a distance of many yards of air to a fine steel needle, - polished to reflect light; but no result came from those - experiments. About the same time, or soon after, certainly not - long before the end of his working time, he was engaged (I - believe at the Shot Tower, near Waterloo Bridge, on the Surrey - side) in efforts to discover relations between gravity and - magnetism, which also led to no result. - -[Sidenote: KELVIN’S APPRECIATION.] - -Lord Kelvin, who was himself the first to perceive that Faraday’s ideas -were not inconsistent with mathematical expression, and to direct Clerk -Maxwell and others to this view, had, in 1854, delighted the old man -by bringing mathematical support to the conception of lines of force. -In 1857 he sent to Faraday a copy of one of his papers, and received -in acknowledgment a letter of warm encouragement, which, however, does -not appear to have been preserved. Lord Kelvin’s reply is its own best -commentary:-- - - Such expressions from you would be more than a sufficient - reward for anything I could ever contemplate doing in science. - I feel strongly how little I have done to deserve them, but - they will encourage me with a stronger motive than I have - ever had before to go on endeavouring to see in the direction - you have pointed, which I long ago learned to believe is the - direction in which we must look for a deeper insight into - nature. - - - - -CHAPTER VIII - -RELIGIOUS VIEWS. - - -The name of Glasites or Sandemanians is given to a small sect of -Christians which separated from the Scottish Presbyterian Church -about 1730 under the leadership of the Rev. John Glas. Most of the -congregations which sprang up in England were formed in consequence -of the dissemination of the writings and by the preaching of Robert -Sandeman, son-in-law and successor of Glas. Hence the double name. The -Sandemanian Church in London was constituted about 1760. It still has -a chapel in Barnsbury, though the sect as a whole--never numerous--has -dwindled to a small remnant.[58] The religious census of 1851 showed -but six congregations in England and six in Scotland. As it never was -a proselytising body, it is probable that it has diminished since that -date. John Glas was deposed in 1728 by the Presbyterian Courts from his -position as minister in the Scottish Church, because he taught that -the Church should be governed only by the doctrines of Christ and His -apostles, and not be subject to any League or Covenant. He held that -the formal establishment by any nation of a professed religion was -the subversion of primitive Christianity; that Christ did not come to -establish any worldly authority, but to give a hope of eternal life to -His people whom He should choose of His own sovereign will; that “the -Bible,” and it alone, with nothing added to it nor taken away from it -by man, was the sole and sufficient guide for each individual, at all -times and in all circumstances; that faith in the divinity and work -of Christ is the gift of God, and that the evidence of this faith is -obedience to the commandment of Christ. - -[Sidenote: THE SANDEMANIAN CREED.] - -The tenets of Glas are somewhat obscure and couched in mystical -language. They prescribe a spiritual union which binds its members into -one body as a Church without its being represented by any corresponding -outward ecclesiastical polity. He died in 1773. Sandeman, who spent -most of his life in preaching these doctrines, died about the same time -in New England. He caused to be inscribed on his tomb that “he boldly -contended for the ancient faith that the bare death of Jesus Christ, -without a deed or thought on the part of man, is sufficient to present -the chief of sinners spotless before God.” - -[Sidenote: A PRIMITIVE CHURCH.] - -The Sandemanians try--so far as modern conditions permit--to live up -to the practice of the Christian Church as it was in the time of the -Apostles. At their chapel they “broke bread” every Lord’s day in the -forenoon, making this a common meal between the morning and afternoon -services, and taking their places by casting lots. And weekly, at -their simple celebration of the Lord’s Supper at the close of the -afternoon service, before partaking, they collect money for the support -of the poor and for expenses. In some places they dined together at -one another’s houses instead of at the chapel. “They esteem the lot -as a sacred thing. The washing of the feet is also retained: not, it -would seem, on any special occasion, but the ablution is performed -‘whenever it can be an act of kindness to a brother to do so.’ Another -peculiarity of this religious body is their objection to second -marriages.”[59] Members are received into the Church on the confession -of sin and profession of faith made publicly at one of the afternoon -services. In admitting a new member they give the kiss of charity. -They deem it wrong to save up money; “the Lord will provide” being an -essential item of faith. Traces of this curious fatalism may be found -in one of Faraday’s letters to his wife (p. 52). He seems always to -have spent his surplus income on charity. The Sandemanians have neither -ordained ministers nor paid preachers. In each congregation, however, -there are chosen elders (presbyters or bishops), of whom there must -always be a plurality, and of whom two at least must be present at -every act of discipline. The elders take it in turns to preside at the -worship, and are elected by the unanimous choice of the congregation. -The sole qualification for this office, which is unpaid, is that -earnestness of purpose and sincerity of life which would have been -required in Apostolic times for the office of bishop or presbyter. No -difference of opinion is tolerated, but is met by excommunication, -which amongst families so connected by marriage produces much -unhappiness, since they hold to the Apostle’s injunction, “With such an -one, no, not to eat.” - -The foregoing summary is needed to enable the reader to comprehend -the relationship of Faraday to this body. His father and grandfather -had belonged to this sect. In 1763 there was a congregation at Kirkby -Stephen (the home of Faraday’s mother) numbering about thirty persons; -and there appears to have been a chapel--now used as a barn--in -Clapham. A strong religious feeling had been dominant in the Faraday -family through the preceding generation. James Faraday, on his removal -to London, there joined the Sandemanian congregation, which at that -time met in a small chapel in St. Paul’s Alley, Barbican, since pulled -down. It had, when founded in 1762, held its first meetings in the hall -of the Glovers’ Company, and later in Bull and Mouth Street, till 1778. -James Faraday’s wife, mother of Michael Faraday, never formally joined -the Sandemanian Church, though a regular attendant of the congregation. -Michael Faraday was from a boy brought up in the practice of attending -this simple worship, and in the atmosphere of this primitive religious -faith. Doubtless such surroundings exercised a moulding influence on -his mind and character. The attitude of abstinence from attempts to -proselytise, on the part of the church, finds its reflex in Faraday’s -habitual reticence, towards all save only the most intimate of friends, -on matters of religious faith. “Never once,” says Professor Tyndall, -“during an intimacy of fifteen years, did he mention religion to me, -save when I drew him on to the subject. He then spoke to me without -hesitation or reluctance; not with any apparent desire to ‘improve the -occasion,’ but to give me such information as I sought. He believed the -human heart to be swayed by a power to which science or logic opened no -approach; and right or wrong, this faith, held in perfect tolerance of -the faiths of others, strengthened and beautified his life.” - -[Sidenote: HIS PROFESSION OF FAITH.] - -Of his spiritual history down to the time of his marriage very little -is known, for he made no earlier profession of faith. It is not to -be supposed that he who was so scrupulous of truth, so single-minded -in every relation of life, would accept the religious belief of his -fathers without satisfying his conscience as to the rightness of its -claims. Yet none of his letters or writings of that period show any -trace[60] of that stress of soul through which at one time or another -every sincere and earnest seeker after truth must pass before he -finds anchorage. Certain it is that he clung with warm attachment to -the little self-contained sect amongst whom he had been brought up. -Its influence, though contracting his activities by precluding all -Christian communion or effort outside their circle, and cutting him -off from so much that other Christian bodies hold good, fenced him -effectually from dreams of worldliness, and furnished him with that -very detachment which was most essential to his scientific pursuits. -One month after his marriage he made his confession of sin and -profession of faith before the Sandemanian Church. It was an act of -humility the more striking in that it was done without any consultation -with his wife, to whom he was so closely attached, and who was already -a member of the congregation. When she asked him why he had not told -her what he was about to do, he replied: “That is between me and my -God.” - -In 1844 he wrote to Lady Lovelace as follows:-- - -“You speak of religion, and here you will be sadly disappointed in -me. You will perhaps remember that I guessed, and not very far aside, -your tendency in this respect. Your confidence in me claims in return -mine to you, which indeed I have no hesitation in giving on fitting -occasions, but these I think are very few, for in my mind religious -conversation is generally in vain. _There is no philosophy in my -religion._ I am of a very small and despised sect of Christians, known, -if known at all, as Sandemanians, and our hope is founded on the faith -that is in Christ. But though the natural works of God can never by -any possibility come in contradiction with the higher things that -belong to our future existence, and must with everything concerning -Him ever glorify Him, still I do not think it at all necessary to tie -the study of the natural sciences and religion together, and, in my -intercourse with my fellow creatures, that which is religious and that -which is philosophical have ever been two distinct things.” - -His own views were stated by himself at the commencement of a lecture -on _Mental Education_ in 1854:-- - - High as man is placed above the creatures around him, there - is a higher and far more exalted position within his view; - and the ways are infinite in which he occupies his thoughts - about the fears, or hopes, or expectations of a future life. - I believe that the truth of that future cannot be brought to - his knowledge by any exertion of his mental powers, however - exalted they may be; that it is made known to him by other - teaching than his own, and is received through simple belief - of the testimony given. Let no one suppose for a moment that - the self-education I am about to commend, in respect of the - things of this life, extends to any considerations of the hope - set before us, as if man by reasoning could find out God. It - would be improper here to enter upon this subject further than - to claim an absolute distinction between religious and ordinary - belief. I shall be reproached with the weakness of refusing to - apply those mental operations which I think good in respect - of high things to the very highest. I am content to bear the - reproach. - -One of his friends wrote: “When he entered the meeting-house he left -his science behind, and he would listen to the prayer and exhortation -of the most illiterate brother of his sect with an attention which -showed how he loved the word of truth, from whomsoever it came.” - -[Sidenote: AS ELDER AND PREACHER.] - -“The most remarkable event,” says Dr. Bence Jones, “of his life in 1840 -was his election as an elder of the Sandemanian Church. During that -period when in London he preached on alternate Sundays.” This was not -an entirely new duty, for he had been occasionally called upon by the -elders, from the date of his admission in 1821, to exhort the brethren -at the week-day evening meetings, or to read the Scriptures in the -congregation. Bence Jones says that, though no one could lecture like -Faraday, many might preach with more effect. The eager and vivacious -manner of the lecture-room was exchanged for a devout earnestness -that was in complete contrast. His addresses have been described as a -patchwork of texts cited rapidly from the Old and New Testaments; and -they were always extempore, though he prepared careful notes on a piece -of card beforehand. Of these, samples are given in Bence Jones’s “Life -and Letters.” His first discourse as an elder was on Matt. xi. 28–30, -dilating on Christ’s character and example. “Learn of Me.” The ground -of humility of Christians must be the infinite distance between them -and their Pattern. He quoted 1 John ii. 6; 1 Peter ii. 21; Phil. iii. -17; 1 Cor. xi. 1; and 1 Cor. xiv. 1. - -An exceedingly vivid view of Faraday as elder of the Church was given -in 1886[61] by the late Mr. C. C. Walker, himself at one time a member -of the Sandemanian congregation in London; a congregation, moreover, -which included several persons of distinction--Cornelius Varley, the -engraver, and George Barnard, the water-colour painter. - - At Faraday’s chapel there was a presiding elder, supported by - the rest of the elders on two rows of seats elevated across - the end of the chapel, one row above the other. The ground - floor was filled with the old-fashioned high pews, and there - was a gallery above on both sides, also with pews. Faraday sat - in a pew on the ground floor, about the middle. There was a - large table on the floor of the chapel in front of the elders’ - seats. The presiding elder usually preached. Such was the place - Faraday worshipped in, situated at the end of a narrow dirty - court, surrounded by squalid houses of the poorest of the poor, - and so little known that although I knew every street, lane - and alley of the whole district, and this alley itself, at the - bottom of which the chapel was, I never knew of the existence - of the meeting-house till I learned about thirty-five years - ago that there was a chapel there to which the world-renowned - Faraday not only went, but where he preached. This led me to - make a search, and to my great delight, I found it, though with - some difficulty. Although the neighbourhood was uncleanly, not - so was the interior of the chapel, nor the dining room, with - its tables and forms, all of which were spotless. - - Faraday’s father was a blacksmith, and worshipped here. He - brought up his family religiously, and Faraday from his - earliest days attended the chapel. Here he met Miss Barnard, - his future wife. Mr. Barnard was a respectable “working - silversmith,” as manufacturing silversmiths were then called, - to distinguish them from the shopkeepers who then, as now, - called themselves “silversmiths,” though frequently making none - of the goods they sell. His manufactory was for a time at Amen - Court, Paternoster Row; afterwards it was removed to a large - building erected by the firm at Angel Street, near the General - Post Office, and the business has since been carried on by the - sons and grandsons. - - [Sidenote: RELIGIOUS SERVICE.] - - Mr. Barnard and his family worshipped at the Sandemanian - Chapel. To this chapel Faraday walked every Sunday morning from - his earliest days; he never kept a carriage, and on religious - principles would not hire a cab or omnibus on the Lord’s - day.[62] - - The service commenced at eleven in the morning and lasted till - about one, after which the members--“brothers and sisters,” - as they called each other--had their midday meal “in common” - in the room attached to the chapel, which has already been - referred to. The afternoon worship usually ended about five - o’clock, after partaking of the Lord’s Supper. The services - were very much like those of the Congregationalists, and - consisted of extempore prayers, hymns, reading the Scripture, - and a sermon, usually by the presiding elder. Faraday had been - an elder for a great many years, and for a considerable time - was the presiding elder, and consequently preached; but during - this time relinquished his office. There was one peculiarity - in the service; the Scriptures were not read by the presiding - elder, but he called on one of the members to read; and when - Faraday was there--which he always was when in London--the - presiding elder named “Brother Michael Faraday,” who then - left his pew, passing along the aisle, out of the chapel, up - the stairs at the back, and reappeared behind the presiding - elder’s seat, who had already opened the large Bible in front - of him, and pointed out the chapter to be read. It was one of - the richest treats that it has been my good fortune to enjoy to - hear Faraday read the Bible. The reader was quite unaware what - he was to read until it was selected and when one chapter of - the Old Testament was finished another would be given, probably - from the New Testament. Usually three chapters were read, and - sometimes four, in succession; but if it had been half a dozen - there would have been no weariness, for the perfection of the - reading, with its clearness of pronunciation, its judicious - emphasis, the rich musical voice, and the perfect charm of - the reader, with his natural reverence, made it a delight to - listen. I have heard most of those who are considered our best - readers in church and chapel, but have never heard a reader - that I considered equal to Faraday. - - At this distance of time his tones are always in my ears. - - * * * * * - - I was told by members of the chapel that he was most assiduous - in visiting the poorer brethren and sisters at their own homes, - comforting them in their sorrows and afflictions, and assisting - them from his own purse. Indeed, they said, he was continually - pressed to be the guest of the high and noble (which we may - well believe), but he would, if possible, decline, preferring - to visit some poor sister in trouble, assist her, take a cup - of tea with her, read the Bible and pray. Though so full of - religion, he was never obtrusive with it; it was too sacred a - thing. - -Tyndall has preserved another vivid reminiscence of Faraday’s inner -life, which he wrote down after one of the earliest dinners which he -had in the Royal Institution. - -“At two o’clock he came down for me. He, his niece, and myself formed -the party. ‘I never give dinners,’ he said; ‘I don’t know how to give -dinners; and I never dine out. But I should not like my friends to -attribute this to a wrong cause. I act thus for the sake of securing -time for work, and not through religious motives as some imagine.’ He -said grace. I am almost ashamed to call his prayer a ‘saying’ of grace. -In the language of Scripture, it might be described as the petition -of a son into whose heart God had sent the Spirit of His Son, and who -with absolute trust asked a blessing from his Father. We dined on -roast beef, Yorkshire pudding, and potatoes, drank sherry, talked of -research and its requirements, and of his habit of keeping himself free -from the distractions of society. He was bright and joyful--boylike, -in fact, though he is now sixty-two. His work excites admiration, but -contact with him warms and elevates the heart. Here, surely, is a -strong man. I love strength, but let me not forget the example of its -union with modesty, tenderness, and sweetness, in the character of -Faraday.” - -There is a story told by the Abbé Moigno that one day at Faraday’s -request he introduced him to Cardinal Wiseman. In the frank interview -which followed, the Cardinal did not hesitate to ask Faraday whether, -in his deepest conviction, he believed all the Church of Christ, holy, -catholic, and apostolic, was shut up in the little sect in which he was -officially an elder. “Oh, no!” was Faraday’s reply; “but I do believe -from the bottom of my soul that Christ is with us.” - -[Sidenote: ELDERSHIP INTERRUPTED.] - -The course of Faraday’s eldership was, however, interrupted. It was -expected of an elder that he should attend every Sunday. One Sunday -he was absent. When it was discovered that his absence was due to his -having been “commanded” to dine with the Queen at Windsor, and that so -far from expressing penitence, he was prepared to defend his action, -his office became vacant. He was even cut off from ordinary membership. -Nevertheless, he continued for years to attend the meetings just as -before. He would even return from the provincial meetings of the -British Association to London for the Sunday, so as not to be absent. -In 1860 he was received back as an elder, which office he held again -for about three years and a half, and finally resigned it in 1864. - -It is doubtful whether Faraday ever attempted to form any connected -ideas as to the nature or method of operation of the Divine government -of the physical world, in which he had such a whole-souled belief. -Newton has left us such an attempt. Kant in his own way has put forward -another. So did Herschel; and so in our time have the authors of “The -Unseen Universe.” To Faraday all such “natural theology” would have -seemed vain and aimless. It was no part of the lecturer on natural -philosophy to speculate as to final causes behind the physical laws -with which he dealt. Nor, on the other hand, was it the slightest use -to the Christian to inquire in what way God ruled the universe: it was -enough that He did rule it. - -[Sidenote: RELIGION AND SCIENCE.] - -Faraday’s mental organisation, which made it possible for him to -erect an absolute barrier between his science and his religion, -was an unusual one. The human mind is seldom built in such rigid -compartments that a man whose whole life is spent in analysing, -testing, and weighing truths in one department of knowledge, can cut -himself off from applying the same testing and inquiring processes -in another department. The founder of the sect had taught them that -the Bible alone, with nothing added to it or taken away from it by -man, was the only and sufficient guide for the soul. Apparently -Faraday never admitted the possibility of human flaw in the printing, -editing, translation, collation, or construction of the Bible. He -apparently never even desired to know how it compared with the oldest -manuscripts, or what was the evidence for the authenticity of the -various versions. Having once accepted the views of his sect as to the -absolute inspiration of the English Bible as a whole, he permitted no -subsequent question to be raised as to its literal authority. Tyndall -once described this attitude of mind in his own trenchant way by saying -that when Faraday opened the door of his oratory he closed that of his -laboratory. The saying may seem hard, but it is essentially true. To -few indeed is such a limitation of character possible: possibly it may -be unique. We may reverence the frank single-minded simplicity of soul -which dwelt in Faraday, and may yet hold that, whatever limitation -was right for him, others would do wrong if they refused to bring -the powers of the mind--God-given as they believe--to bear upon the -discovery of truth in the region of Biblical research. Yet may none of -them dream of surpassing in transparent honesty of soul, in genuine -Christian humility, in the virtues of kindness, earnestness, and -sympathetic devotion, the great and good man who denied himself that -freedom. - - - - -FOOTNOTES - - -[1] Faraday’s usual place of work at bookbinding was a little room on -the left of the entrance. (_See_ the story of his visit there with -Tyndall in after years, as narrated in Tyndall’s “Faraday,” p. 8.) - -[2] Still preserved in Faraday’s Diploma-book, now in the possession of -the Royal Society. - -[3] An account of this machine will be found in the _Argonaut_, vol. -ii., p. 33. - -[4] “When he [Faraday] was young, poor, and altogether unknown, -Masquerier was kind to him; and now that he is a great man he does not -forget his old friend.”--Diary of H. Crabb Robinson, vol. iii., p. 375. - -[5] He always sat in the gallery over the clock. - -[6] See Dr. Paris’s “Life of Davy,” vol. ii., p. 2; or Bence Jones’s -“Life and Letters of Faraday,” vol. i., p. 47. - -[7] His duties as laid down by the managers were these:--“To attend -and assist the lecturers and professors in preparing for, and during -lectures. Where any instruments or apparatus may be required, to attend -to their careful removal from the model-room and laboratory to the -lecture-room, and to clean and replace them after being used, reporting -to the managers such accidents as shall require repair, a constant -diary being kept by him for that purpose. That in one day in each week -he be employed in keeping clean the models in the repository, and that -all the instruments in the glass cases be cleaned and dusted at least -once within a month.” - -[8] The City Philosophical Society was given up at the time when -Mechanics’ Institutes were started in London, Tatum selling his -apparatus to that established in Fleet Street, the forerunner of the -Birkbeck Institution. Many of the City Society’s members joined the -Society of Arts. - -[9] Two passages may be quoted. “Finally, Sir H. has no valet except -myself ... and ’tis the name more than the thing which hurts.” “When I -return home, I fancy I shall return to my old profession of bookseller, -for books still continue to please me more than anything else.” - -[10] The meeting at which it was actually originated was held under the -presidency of Sir Joseph Banks, P.R.S., nominally as a meeting for the -_Assistance of the Poor!_ - -[11] A writer in the _Quarterly Journal of Science_ for 1868, p. 50, -says: “We have reason to know that Davy was slightly annoyed that the -certificate proposing Faraday for election should have originated with -Richard Phillips, and that he should not have been consulted before -that gentleman was allowed to take the matter in hand.” This is absurd, -because the President was by long-standing etiquette debarred from -signing the certificates of any but foreign members, as the certificate -book of the Royal Society attests. - -[12] See p. 12. - -[13] Liddon’s “Life of E. B. Pusey” (1893), p. 219. - -[14] For this information and many particulars of this transaction I am -indebted to Dr. J. H. Gladstone, F.R.S. - -[15] “It was probably in a four-wheeled velocipede that Faraday was -accustomed, some thirty years ago, to work his way up and down the -steep roads near Hampstead and Highgate. This machine appears to have -been of his own construction, and was worked by levers and a crank -axle in the same manner as the rest of the four-wheeled class.”--_The -Velocipede: its past, its present, and its future._ By J. F. B. Firth. -London, 1869. - -[16] Except on nickel and cobalt, which are also para-magnetic metals. - -[17] For a graphic account by Hansteen of the circumstances of -Oersted’s discovery, see Bence Jones’s “Life and Letters of Faraday,” -vol. ii. p. 390. - -[18] “To the effect which takes place in this conductor [or uniting -wire] and in the surrounding space, we shall give the name of the -_conflict of electricity_.”... - -“From the preceding facts we may likewise collect that this conflict -performs circles; for without this condition, it seems impossible that -the one part of the uniting wire, when placed below the magnetic pole, -should drive it towards the east, and when placed above it towards the -west; for it is the nature of a circle that the motions in opposite -parts should have an opposite direction.”--H. C. OERSTED, _Ann. of -Phil._, Oct., 1820, pp. 273–276. - -[19] This is an error due to haste in writing. - -[20] See a paper by the author in the _Philosophical Magazine_ for -June, 1895, entitled “Note on a Neglected Experiment of Ampère.” - -[21] Compare Dumas, “Éloge Historique de Michel Faraday,” p. xxxiii., -who gives the above statement. Arago’s own account to the _Académie_ -differs slightly. - -[22] This ring Faraday is represented as holding in his hand in the -beautiful marble statue by Foley which stands in the Entrance Hall of -the Royal Institution. The ring itself is still preserved at the Royal -Institution amongst the Faraday relics. The accompanying cut (Fig. 4) -is facsimiled from Faraday’s own sketch in his laboratory note-book. - -[23] Now in the possession of the author, to whom it was given by his -kinswoman Lady Wilson, youngest daughter of Richard Phillips. - -[24] The day of the Annual Meeting and election of Council of the Royal -Society. - -[25] This is a slip in the description; the momentary current induced -in the secondary wire on making the current in the primary is -_inverse_: it is succeeded by a momentary _direct_ current when the -primary current is stopped. - -[26] This doubtless refers to Whewell, of Cambridge, whom he was in the -habit of consulting on questions of nomenclature. - -[27] A man of fashion who had, without any claim to distinction, wormed -himself into scientific society, posed as a savant, and had delivered a -high-flown oration on botany at the Royal Institution. - -[28] The use of this term, as distinguished from production, to -distinguish between the primary generation of a current in a voltaic -cell, a thermopile, or a friction-machine, by chemical or molecular -action, and its indirect production without contact or communication of -any material sort, as by motion of a wire near a magnet or by secondary -influence from a neighbouring primary current while that current is -varying in strength or proximity, is exceedingly significant. Faraday’s -own meaning in adopting it is best grasped by referring to p. 1 of the -“Experimental Researches”:-- - - “On the _Induction_ of Electric Currents.”... The general - term _induction_ which, as it has been received into - scientific language, may also, with propriety, be used to - express the power which electrical currents may possess of - inducing any particular state upon matter in their immediate - neighbourhood.... I propose to call this action of the current - from the voltaic battery _volta-electric induction_ ... but as - a distinction in language is still necessary, I propose to call - the agency thus exerted by ordinary magnets _magneto-electric - or magne-electric_ induction. - - -[29] “Experimental Researches,” i. 25, art. 85. This copper disc is -still preserved at the Royal Institution. It was shown in action by the -author of this work, at a lecture at the Royal Institution delivered -April 11th, 1891. Fig. 6 is reproduced in facsimile from Faraday’s -laboratory note-book. - -[30] “Experimental Researches,” i. art. 135. - -[31] _Ib._, art. 155. - -[32] _Ib._, art. 158. - -[33] _Ib._, art. 219. - -[34] “Experimental Researches,” i. art. 220. - -[35] _Ib._, art. 222. - -[36] _Ib._, iii. art. 3192. - -[37] “Ann. Chim. Phys.,” li. 76, 1832. - -[38] The great magnet of the Royal Society, which was at this time lent -to Mr. Christie. - -[39] [Original footnote by Faraday.] By magnetic curves, I mean the -lines of magnetic force, however modified by the juxtaposition of -poles, which would be depicted by iron filings; or those to which a -very small magnetic needle would form a tangent. - -[40] The entire uselessness as well as the misleading effects of -such unscientific nomenclature might well be taken to heart by those -electrophysiologists and electrotherapeutists who still indulge in the -jargon of “franklinisation,” “faradisation,” and “galvanisation.” - -[41] In modern language this would be called the time-integral of -the discharge. The statement is strictly true if the galvanometer -(as was the case with Faraday’s) is one of relatively long period of -oscillation. - -[42] From ἄνω _upwards_ and ὁδός _a way_; and κατά _downwards_ and ὁδός -_a way_. The words _cathode_ and _cation_ are now more usually spelled -_kathode_ and _kation_. Faraday sometimes spelled the word _cathion_ -(Exp. Res. Art. 1351), as did also Whewell (Hist. of Ind. Sciences, -vol. iii. p. 166). - -[43] Literally, _the travellers_, the things which are going. - -[44] The term _induction_ appears to have been originally used, in -contradistinction to _contact_ or _conduction_, to connote those -effects which apparently are in the class of actions at a distance. -Thus we may have induction of a charge by a charge, or of a magnet-pole -by a magnet-pole. To these Faraday had added the induction of a current -by a current, and the induction of a current by a moving magnet. Amid -such varying adaptations of the word _induction_, there is much gain -in allotting to the electrostatic induction of charges by charges the -distinguishing name of _influence_, as suggested by Priestley. - -[45] “Faraday as a Discoverer,” p. 67. - -[46] Newton’s third letter to Bentley. - -[47] Faraday’s definition is:--“By a _diamagnetic_, I mean a body -through which lines of magnetic force are passing, and which does not -by their action assume the usual magnetic state of iron or loadstone.” -It was thus a term strictly analogous to the term _dielectric_ used for -bodies through which lines of electric force might pass. - -[48] _i.e._ Specimen No. 174. Its composition was equal parts by weight -of boracic acid, oxide of lead, and silica. - -[49] Subsequent investigation has reduced this figure to about 186,400 -miles per second, or about 30,000,000,000 centimetres per second. - -[50] The accompanying diagram (Fig. 20) was not given by Faraday. It -was pencilled by the author more than twenty years ago in the margin -of his copy of Faraday’s “Experimental Researches,” vol. iii., p. 450, -opposite this passage. - -[51] The discourse was to have been delivered by Wheatstone himself, -who, however, at the last moment, overcome by the shyness from which he -suffered to an almost morbid degree, quitted the Institution, and left -the delivery of the discourse to Faraday. - -[52] The italics here are mine. S. P. T. - -[53] It is right to add that what, according to the theory explained in -the text, must be the correct explanation of the peculiar phenomena of -magnetic induction depending on magnecrystallic properties was clearly -stated in the form of a conjecture by Faraday in his twenty-second -series in the following terms: “Or we might suppose that the crystal -is a little more apt for magnetic induction, or a little less apt -for diamagnetic induction, in the direction of the magnecrystallic -axis than in other directions” (Sir William Thomson, _Philosophical -Magazine_, 1851, or “Papers on Electrostatics and Magnetism,” p. 476). - -[54] This is exactly Stokes’s theorem of “tubes” of force. S. P. T. - -[55] The italics are mine. S. P. T. - -[56] Once again did Faraday intervene in Royal Society affairs at -the crucial time when Lord Rosse was elected President in 1848. The -following excerpts from the journals of Walter White show the cause:-- - -“November 25th.--There have been many secret conferences this -week--much trimming and time-serving. Alas for human nature!” - -“November 30th.--The eventful day, the ballot begun. Mr. Faraday made -some remarks about the list.” - -[57] He was a Chevalier of the Prussian Order of Merit, also Commander -in the Legion of Honour, and Knight Commander of the Order of St. -Maurice and St. Lazarus. - -[58] Faraday’s nephew, Frank Barnard, stated in 1871 that the London -congregation included amongst its members not more than twenty men, -mostly quite poor, only seven or eight of them being masters of their -own businesses, and that Faraday was for some time the wealthiest man -of the fraternity. - -[59] C. M. Davies: “Unorthodox London,” page 284. - -[60] A letter from his nephew, Frank Barnard, to Dr. Gladstone says: -“I believe that in his younger days he had his period of hesitation, -of questioning in that great argument. I have heard that, so alive was -he to the necessity of investigating anything that seemed important, -he visited Joanna Southcote, perhaps to learn what that woman’s -pretensions were: I think he was a mere lad at that time. But this -period once passed, he questioned no more, for the more he saw that -Nature was mighty, the more he felt that God was mightier; and to any -cavillings upon the doubts of Colenso or the reality of the Mosaic -cosmogony, I believe he would simply have replied in the apostle’s -words: ‘Is anything too hard for God?’... - -“I once heard him say from the pulpit, ‘I hope none of my hearers will -in these matters listen to the thing called philosophy.’” - -[61] _Manchester Guardian_, November 27. - -[62] [This is not altogether accurate. Certainly in his later life -Faraday used to hire a cab to take him and Mrs. Faraday to the chapel. -S. P. T.] - - - - -INDEX - - - Abbott, Benjamin, 7, 8, 97, 227; - letters to, 7, 9, 15, 22, 25, 26, 41, 44, 228 - - Acoustical researches, 136 - - Action at a distance unthinkable, 128, 153, 157, 216 - - Admiralty, Scientific adviser to the, 68 - - Æther, the, Speculations upon, 193, 213 - - Airy, Sir George, Dispute with, 269 - - Aloofness from scientific organisations, 264 - - Ampère, Andrée Marie: - Meeting with, 19; - his researches, 80, 82, 85, 105, 126 - - Analyst, Faraday’s professional work as, 51, 61, 63, 274 - - Anderson, Sergeant: - engaged as assistant, 96; - his implicit obedience, 97, 242 - - Andrews, Professor T., Letter to, 273 - - Apparatus, Simplicity of, 239 - - Arago, F.: - Meeting with, 34, 238; - his notations, 106, 116, 118; - his philosophical reserve, 107 - - Armstrong, Lord, on electrification of steam, 170 - - Artists amongst acquaintances, 246 - - Astley’s Theatre, 51 - - Athenæum Club, 59 - - Atmospheric magnetism, 206, 209, 210 - - Atoms or centres of force, 241 - - Autobiographical notes, 8, 17, 50, 58, 70, 71, 73, 76, 223, 243 - - - B. - - Babbage, Charles, 107, 116, 262 - - Barnard, Edward, 46 - - ----, Frank, 250, 286 - - ----, George, 46, 51, 74, 89, 224, 246, 294 - - ----, Miss Jane, 46, 259 - - ----, ---- Sarah (Mrs. Faraday), 46, 294 - - Becker, Dr., Letter to, 244 - - Bence Jones’s “Life and Letters of Faraday,” 7, 26, 40, 43, 48, 57, - 58, 78, 108, 199, 226, 231, 293 - - Benzol, Discovery of, 94, 101 - - Bidwell, S., magnetic action of light, 184 - - Biographies of Faraday (_see_ PREFACE) - - Boltzmann: - on crystalline dielectrics, 166; - on the doctrines of Faraday and Maxwell, 216 - - Bookbinding, 5, 6, 17, 249 - - Bookselling, 5, 17, 26, 31 - - Books by Faraday: - “On the Means of Obtaining Knowledge,” 41; - “Chemical Manipulations,” 101, 233; - “On Alleged Decline of Science in England” (editor), 110; - “Experimental Researches in Electricity and Magnetism,” 102; - “Experimental Researches in Chemistry and Physics,” 76; - “On the Prevention of Dry Rot in Timber,” 149; - “Chemistry of a Candle,” 234; - “The Forces of Nature,” 234 - - Boots, a home-made pair of, 249 - - Brande, W. F., Prof., 39, 57 - - Breakdown in health, 170, 199, 222, 259 - - British Association, 64, 224, 264, 268, 297 - - Browning, Mrs. E. B., denounces Faraday, 251 - - Burdett-Coutts, Baroness, Letter to, 240 - - - C. - - Cards, Use of, to assist memory, 7, 239 - - Charge, electric, Query as to seat of, 154 - - ----, The nature of an electric, 152 - - Charitable gifts, 245, 296 - - Chemical researches, 45, 82, 87; - analysis of caustic lime, 76; - new chlorine compounds, 87; - liquefaction of chlorine, 93; - discovery of benzol, 94; - sulpho-naphthalic acid, 100 - - Chemistry, How to examine in, 277 - - Children and Faraday, 233, 235 - - Chlorine, Liquefaction of, 55, 91 - - Christmas lectures, 33, 37, 61, 101, 233, 234, 235, 258 - - City Philosophical Society, 14, 16, 40, 41, 230 - - Clerk Maxwell, J.: - article on Faraday, 135; - theory of conduction, 155; - electromagnetic theory of light, 199; - on Faraday’s conception of electric action, 217; - letter to, on mathematics, 281 - - Closing days of Faraday’s life, 259 - - Coinage of new words, 116, 143, 144, 163, 188, 205 - - Commonplace books, 40, 89 - - Conduction, Theory of, 155 - - Conservation of energy, 167, 219 - - Contact theory of cells, 168 - - Continent, Visits to, 16, 17, 74, 224 - - Controversy, Detestation of, 268 - - Convolutions of the forces of nature, 167, 172, 269, 270 - - Copper disc experiment, 113 - - Criticism, Uses of, 14, 231, 240, 269 - - Crosse, Mrs. A., Reminiscences of, 233, 245, 270 - - Crystallisation in relation to electric properties, 166, 167 - - Crystals in the magnetic field, 200, 202 - - Current, Conception of a, 146, 163 - - Cutting the magnetic lines, 134, 213 - - Crookes, Sir W., Advice to, 267 - - - D. - - Dalton, John, 65, 226 - - Dance, Mr., gives Faraday tickets, 8; - message to, 30 - - Daniell, Prof. J. F., 64 - - Davy, Sir Humphry: - lectures of, 8, 36, 227; - note to Faraday, 11; - engages Faraday, 12; - travels abroad, 17; - his aristocratic leanings, 25; - researches on electric arc, 37; - invention of safety lamp, 37, 42, 269; - writes to Faraday, 44, 45; - misunderstanding with, 56; - his jealousy of Faraday, 56, 59; - his electromagnetic discovery, 80; - and the liquefaction of chlorine, 93 - - Davy-Faraday laboratory, The, 36 - - De la Rive, Auguste, 29, 66, 105, 237; - letters to, 29, 185 - - ---- ---- ----, Gustave, 20, 28, 116, 141; - letters to, 83, 85, 91, 207, 267 - - De la Rue, Warren: - his lecture, 39; - his eclipse photographs, 219 - - Diamagnetic, A, 179 - - ---- polarity, 192, 210 - - Diamagnetism, Discovery of, 186 - - Dielectric medium, 153, 159, 163 - - Diploma-book, 271 - - Discharge, electric, Forms of, 137, 162 - - ---- ----, Dark, 162 - - Discoveries, Value of, 63, 224, 248 - - Displacement currents, 166 - - Doctrine of conservation of energy, 167, 219 - - ---- of correlation of forces, 172, 269, 270 - - ---- of electrons, 148 - - Domestic affairs, 49, 69, 244, 257 - - Doubtful knowledge, Aversion for, 46, 92 - - Dry rot in timber, 149 - - Dumas: - Reminiscences by, 20, 59, 240; - and Arago’s copper, 106; - discovery of oxalamide, 137 - - - E. - - Eddy-currents, Effects due to, 107, 191, 204 - - Education, Views on, 278 - - Eel, The electric, 167 - - Electric light for lighthouses, 218, 269 - - Electrical machine, Faraday’s own, 6 - - ---- ----, The “new,” 121 - - Electrochemical laws, 141, 147 - - Electrodes, 143 - - Electrolysis, 143 - - Electrolytes, 143 - - Electromagnetic rotations discovered, 51, 83, 87 - - Electromagnetism, Foundations of, 77 - - Electrons, Doctrine of, 148 - - Electrotonic state, 116, 126, 166, 215 - - Elocution, Lessons in, 43, 230 - - Enthusiasm, 15, 89, 225, 240 - - Ether, The (_see_ ÆTHER) - - Evolution of electricity from magnetism, 108, 114 - - Examinations in chemistry, 277 - - Experiment, Love of, 117, 230, 276 - - ---- the touchstone of hypothesis, 221 - - ---- _versus_ mathematics, 117, 239, 280 - - Experimental researches in electricity and magnetism: - the first series, 113; - the last series, 216; - Clerk Maxwell on, 218 - - Expert work, 51, 61, 63, 274 - - Explosions in the laboratory, 94 - - - F. - - Faraday, James, 1, 2, 224 - - Faraday, Michael: - born, 1; - schooling of, 2; - goes as errand boy, 3; - apprenticed as bookbinder and stationer, 5; - journeyman bookbinder, 9; - attends Tatum’s lectures, 6; - attends Sir H. Davy’s lectures, 8; - acts as Davy’s amanuensis, 10; - engaged at Royal Institution, 12; - his foreign tour with Davy, 16; - visits Paris, 18; - visits Florence, 21; - visits Geneva, 22, 28; - returns to Royal Institution, 34; - lectures at City Philosophical Society, 40, 43; - loyalty to Davy, 42, 59, 269; - begins original work, 46; - falls in love, 46; - his poem to Miss Barnard, 46; - his wedding, 49; - made superintendent of laboratory, 49, 98; - discovers electromagnetic rotations, 51; - elected F.R.S., 59; - made D.C.L. of Oxford, 65; - awarded Copley Medal, 69; - declines professorship in London University, 66; - receives a pension in Civil List, 72; - appointed adviser to Trinity House, 67; - appointed elder in Sandemanian church, 293; - discovers magneto-electric induction, 112, 115; - discovers magneto-optic rotation, 176; - discovers diamagnetism, 186; - readmitted to Sandemanian church, 297; - exposes spiritualistic phenomena, 250; - declines Presidency of Royal Society, 255; - declines presidency of Royal Institution, 255; - resigns professorship at Royal Institution, 259; - resigns advisership to Trinity House, 259; - resigns eldership in Sandemanian church, 259; - decease and funeral, 260 - - ----, Robert, 1, 2, 6, 249, 250 - - ----, Sarah (Mrs. Faraday), 49, 50, 51, 223, 225, 255, 257, 291; - letters to, 47, 48, 52, 53, 256 - - Faraday’s father, 1, 2, 224, 289 - - ---- mother, 1, 2, 12, 17, 22, 33, 41, 69, 289 - - Fatalism, 52, 288 - - Fees for professional work, 51, 61, 244, 274 - - Field, The magnetic; first use of this term, 188 - - Fishes, electrical, Researches on, 20, 139, 167 - - Fluids, Alleged electric and magnetic, 212, 216, 218 - - Foreign travel, 16, 17, 74, 224 - - Fox, Caroline, Reminiscences of, 235 - - _Fraser’s Magazine_ and Faraday’s pension, 72 - - Fresnel’s announcement, 105 - - Friday evenings at the Royal Institution, 33, 60, 100, 101, 149, 166, - 170, 192, 203, 219, 220, 225, 232, 236, 259 - - Fuller, John, founds the Fullerian professorships, 36 - - Funeral, 260 - - - G. - - Gases, Liquefaction of, 55, 91, 171 - - ----, Magnetic properties of, 204, 208 - - Gassiot, J. P., Reminiscences by, 13 - - German language, Views on the, 280 - - Gladstone, Dr. J. Hall, 69, 290 - - Glass, Researches on, 95 - - Glassites (_see_ SANDEMANIANS) - - Gold, Optical properties of, 219 - - Gravity in relation to electricity, 204, 220, 285 - - ----, Speculations as to, 195, 203 - - Grove, Sir Wm., 263, 269 - - Gymnotus, 167 - - - H. - - Hachette, Letter to, 266 - - Hampton Court, House at, 257, 258 - - Hare, R., Letter to, 269 - - Harris, Sir W. Snow, 64, 269 - - Heat, Effect of, on magnetism, 208 - - Heavy-glass, 100, 176 - - Helmholtz, Prof. H. von, 282, 283 - - Henry, Professor Joseph, Reminiscence by, 241 - - Herschel, Sir John, 57, 95, 107, 116, 131, 262, 297 - - Home life, 49, 69, 223, 244, 257 - - Honours awarded to Faraday, 69, 199, 244, 255, 271 - - ----, scientific, Views on, 271 - - Hypotheses, Free use of, 221, 241 - - - I. - - Ice a non-conductor, 140 - - ----, Regelation of, 219 - - Identity of electricity from different sources, 137 - - Imagination, Use of the, 160, 227, 276 - - Incandescent electric lamps, 199 - - Income, 68, 245 - - Indignation against wrong, 227 - - Induced currents, 114 - - Induction (electromagnetic), Discovery of, 114 - - ---- (electrostatic), or influence, 153 - - ----, Meaning of the term, 119 - - Inductive capacity, 159 - - Influence (_see_ INDUCTION) - - Inner conflicts, 226, 290 - - Iodine, Davy’s experiments on, 19, 24, 27 - - Ions, Origin of term, 144, 145 - - - J. - - Jenkin, Wm., observes spark at break, 150, 243 - - Jones (_see_ BENCE JONES) - - Journals of foreign travel, 18, 224 - - Juvenile lectures at Royal Institution, 33, 37, 61, 101, 233, 234, - 235, 258 - - - K. - - Keble, Rev. J., and the hodge-podge of philosophers, 65 - - Kelvin, Lord: - theory of electromotive forces, 148; - on theory of magnetic permeability in æolotropic media, 201; - on Faraday’s views of electricity, 284; - letter from, 285 - - Kerr, Dr. John: - electro-optic discovery, 173; - magneto-optic discovery, 182 - - Kindliness, 226 - - Knighthood no honour, 273 - - Kundt, Aug., magneto-optic discovery, 182 - - - L. - - Laboratories at Albemarle Street, 36, 51, 66, 80, 84, 96 - - Lateral effects of current, 151, 165, 170 - - Lectures at Royal Institution: - Davy’s, 8, 36; - Faraday’s first, 227; - Juvenile, 33, 37, 61, 101, 233, 234, 235, 258; - afternoon, 37, 166 - - ----, Friday night discourses, 33, 60, 100, 101, 149, 166, 170, 192, - 203, 219, 220, 225, 232, 236, 259 - - Lectures at the London Institution, 101 - - ---- at the British Association, 264 - - ---- at St. George’s Hospital, 166 - - ---- at Woolwich, 66, 101 - - Lecturing, Views about, 16, 226, 232, 238 - - Letters from Faraday to: - Abbott, B., 7, 9, 15, 22, 25, 26, 41, 44, 228; - Andrews, T., 273; - Barnard, Miss Sarah, 47, 48; - Becker, Dr., 244; - Burdett-Coutts, Baroness, 240; - Davy, Sir H., 10; - De la Rive, A., 29, 185; - De la Rive, G., 83, 85, 91, 207, 267; - Deacon, Mrs., 253; - Faraday, Mrs., 52, 53, 256; - Grove, Sir Wm., 263; - Hare, R., 269; - Lovelace, Lady, 291; - Matteucci, Prof. C., 253, 262, 267; - Melbourne, Lord, 71; - Moore, Miss, 207; - Murray, Mr. John, 234; - Paris, Dr. J. A., 10, 93; - Percy, Dr. J., 253; - Phillips, R., 61, 109, 114, 194, 270, 277; - Riebau, G., 30; - Royet, Dr. P., 99; - Schönbein, Professor, 206, 252; - the Deputy-Master of Trinity House, 67; - Tyndall, Prof. J., 210, 264, 268, 277, 278, 280; - Whewell, Rev. W., 145; - Young, Dr. T., 97 - - ---- to Faraday: - From Sir H. Davy, 44, 45; - from Baron Liebig, 225; - from Sir W. Thomson (Lord Kelvin), 285; - from Rev. W. Whewell, 116, 144, 145, 163, 205 - - Liebig, J. von, Reminiscences by, 224, 282 - - Light, Action of magnetism on, 176 - - ----, Electromagnetic theory of, 197, 199, 213 - - Lighthouses, Scientific work for, 67, 199, 218, 259 - - Lines of force, 113, 133, 195, 208, 211, 213, 285; - vibrations of, 195 - - Liquefaction of gases, 55, 91, 171 - - London University (_see_ UNIVERSITY) - - Love of children, 233, 235 - - ----, Poetical diatribe against, and recantation, 40, 47 - - Lovelace, Lady, Letter to, 291 - - Love-letters of Faraday, 47, 48, 52, 58, 256 - - - M. - - Magnecrystallic forces, 201 - - Magnetic lines, 113, 133, 195, 213, 214 - - Magnetisation by light, 183 - - ---- of light, 176 - - Magnetism and cold, 167 - - ---- of gases, 204 - - ---- of rotation, Alleged, 106, 121 - - Magneto-electric discovery, 95, 112 - - ---- induction, 115 - - ---- light, 120, 130, 218, 259 - - ---- machines, 122, 125, 126, 218, 259 - - Magneto-optical researches, 176, 182, 220 - - Magrath, E., 7, 14, 60, 231 - - Marcet, Mrs., Conversations on Chemistry, 6 - - Masquerier teaches Faraday to draw, 8 - - Mathematics _versus_ experiment, 117, 239, 280 - - ----, Faraday’s views on, 280, 281 - - ---- and Faraday’s methods, 217, 282 - - Matteucci, C., Letters to, 253, 262, 267 - - Maxwell (_see_ CLERK MAXWELL) - - Mayo, Herbert, Impromptu by, 117 - - Meat-canning processes, 243 - - Medium, Action in a, 157, 213, 216 - - ----, The part played by the, 128, 153, 158, 194, 213 - - Melbourne, Lord, and Faraday’s pension, 69 - - Memory, Troubles of a defective, 7, 63, 74, 253 - - Mental education, Views on, 278, 292 - - Models, Use of, 104, 239 - - Moigno, Abbé, Reminiscence by, 297 - - Moll, G.: - his electromagnets, 120; - pamphlet on “Decline of Science,” 110, 262 - - Moore, Miss, Letter to, 207 - - Morichini’s experiments on magnetisation by light, 21, 183 - - Murchison, Sir R., Reminiscence by, 227 - - Music, Enjoyment of, 246 - - - N. - - Natural theology, Views on, 298 - - New electrical machine, 121 - - Newman, Rev. J. H., and the British Association, 65 - - Newton, Mr. Jos., Reminiscence by, 254 - - Nobili and Antinori, their mistake, 266 - - Non-inductive winding, 150 - - Notebooks a better test than examinations, 277 - - ----, Faraday’s own, 8, 50, 73, 87, 90, 91, 108, 111, 118, 129, 141, - 143, 150, 153, 156, 167, 177, 180, 181, 182, 220 - - - O. - - Oersted’s discovery of electromagnetism, 77, 78 - - Optical glass, Research on, 95, 100 - - ---- illusions, Research on, 136 - - ---- relations of electricity, 91, 149, 155, 167, 172, 174, 175 - - ---- ---- of magnetism, 176, 182, 220 - - Order and method, 68, 99, 200 - - Owen, Lady, Reminiscences by, 236 - - Oxford and the philosophers, 64 - - Oxygen, Magnetic properties of, 208 - - - P. - - Paris, Dr. J. A., Letters to, 10, 93 - - Passive state of iron, 167 - - Peel, Sir Robert, 69, 70, 246 - - Pension: - declined, 71; - accepted, 72 - - Percy, Dr. John, Letter to, 253 - - Permeability, Magnetic, in crystals, 201 - - ---- ----, Research on, 206 - - Personal appearance, 4, 18, 74, 255 - - Phillips, Richard, 7, 44, 52, 54, 57, 59, 61, 84, 87, 193; - letters to, 61, 109, 114, 194, 270, 277 - - Phosphorescence, Lectures on, 136, 219 - - Plücker, Julius: - on magneto-optic action, 203; - shows electric discharge, 240 - - Poetry by Faraday, 40, 47 - - Poisson: - on Arago’s rotations, 107; - on magnetic theory, 201 - - Polar forces in crystals, 94, 200, 202 - - Polemics in science hateful, 268 - - Poles are only doors, 141, 241 - - Politics, Indifference to, 19, 21, 33, 268 - - Pollock, Lady, Reminiscences by, 235, 254, 257 - - Practical applications of science, 63, 216, 224, 248, 259 - - Preaching, Style of, 293 - - Preservation of Raphael’s cartoons, 246 - - Prince Consort, H.R.H. the, 237, 257, 278 - - Principle of all dynamo machines, 216 - - Priority in discovery, 265 - - Professional work for fees, 51, 61, 274 - - ---- ---- relinquished, 61, 274, 275 - - Professorship of Chemistry at University College, The, 66, 277; - declined, 66 - - Professorships at the Royal Institution, 36 - - Proportional judgment advocated, 242 - - Public Schools Commission, Evidence given before, 278 - - _Punch_, Caricature in, 252 - - Pusey and science, 65 - - - Q. - - _Quarterly Journal of Science_, 39, 46, 75, 76, 82, 88, 92, 94, 104 - - Queen Victoria, 257, 297 - - - R. - - Radiant matter, 40 - - Rain torpedo, The, 20 - - Ray-vibrations, Thoughts on, 193 - - Regelation of ice, 219 - - Reid, Miss, Reminiscences by, 223, 231 - - Religious belief, 51, 289, 291 - - Religious character, 71, 244, 245 - - Remuneration of science, 44, 68, 244, 274 - - Repulsions, magnetic, New, 190 - - Research, Royal Institution as place for, 37 - - ---- unhampered by other duties, 37 - - Researches, Original: - the four degrees of, 241; - Faraday’s first, 76; - Faraday’s last, 220; - division into periods, 75; - summary of, 216 - - Residences: - Weymouth Street, 2; - Royal Institution, 13, 68; - Hampton Court Cottage, 258 - - Retardation of discharge, 161 - - Riebau, George: - Faraday’s employer, 3, 7, 22; - Faraday apprenticed to, 51; - letters and messages to, 29, 34 - - Ring, The famous experiment with the, 108 - - Robinson, H. Crabb, Reminiscences by, 8, 236 - - Röntgen on displacement currents, 166 - - Rotation of plane of polarisation of light, 177 - - Rotations, electromagnetic, Discovery of, 51, 83, 87 - - Royal Institution: - foundation of, 35; - Davy’s lectures at, 8, 36, 39; - precarious state of, 22, 29, 35, 36, 68; - laboratories of, 36; - lectures at the, 37, 166; - Christmas lectures, 33, 37, 61, 101, 233, 234, 235, 258; - Friday night meetings, 33, 60, 100, 101, 149, 166, 170, 192, 203, - 219, 220, 225, 232, 236, 259; - Presidency offered and declined, 255 - - Royal Society: - first papers read to the, 52, 263; - candidature for Fellowship in the, 56, 57, 59; - Faraday’s election as Fellow of the, 59; - committee on optical glass, 95, 99; - Member of Council, 136, 261; - Presidency offered to him, 255, 263; - dissatisfaction with, 262 - - Ruhmkorff’s induction-coil, 219, 225 - - Rumford, Benjamin Count of: - founds the Royal Institution, 35; - Faraday dines with, 34 - - - S. - - Sacrifice for Science, 63, 64, 234, 244 - - Safety-lamp: - Faraday aids Davy to invent the, 42; - controversy about, 269 - - Salaries paid to scientific men, 44, 68, 244, 274 - - Sandemanians, 4, 51, 286 - - Schönbein, Prof., Letters to, 206, 252 - - Science in education, 279 - - ---- teaching, Views on, 278 - - Scientific societies, 261 - - Scoffern, Dr., Anecdote by, 280 - - Self-induction investigated, 150, 151 - - Sermons, Faraday’s, 293 - - Shaftesbury, Earl of, 69 - - Sirium, _alias_ Vestium, 46, 77 - - Sisters, His letters to his, 32 - - Smart, B. H., teaches elocution, 43, 230 - - Snow-Harris (_see_ HARRIS) - - Social character, 245 - - Society of Arts, 14 - - Source of electromotive force in cell, 168 - - South, Sir James, 6, 57, 69, 70, 97, 262 - - Spark from a magnet, 64, 119, 130 - - Specific inductive capacity, 159 - - Spiritualists, Opinion of, 251 - - Steel, Research on, 82 - - Stinginess of British Government towards science, 274 - - Sturgeon, W.: - his invention of the electromagnet, 102, 226; - on Arago’s rotations, 107 - - Submarine cables, 161 - - Sunday observance, 24, 51, 55, 224, 295, 297 - - - T. - - Table-turning explained, 251 - - Tatum’s lectures, 6, 14 - - Testimonials of candidates, Repugnance to, 277 - - Thames impurities, 252 - - Thomson, Sir W. (_see_ KELVIN) - - Thoughts on ray-vibrations, 193 - - Thunderstorms enjoyed, 240 - - Time of propagation of magnetism, 220, 284 - - Toronto, what its university might have been, 277, 278 - - Torpedo, The, 20 - - Trinity House, Scientific adviser to, 67, 199, 218, 259 - - Tubes of force, 211 - - Turner, J. W. M., R.A., Advice to, about pigments, 246 - - Tyndall, Prof.: - reminiscences by, 4, 49, 74, 175, 187, 225, 255, 290, 296, 299; - his “Faraday as a Discoverer,” 4, 130, 157, 169, 202; - letters to, 210, 264, 268, 277, 278, 280 - - - U. - - Utility of discoveries, 63, 224, 248 - - University College, Professorship in, 66, 277 - - University of London: - Senator of, 275; - degrees in science, 275 - - - V. - - Varley, Cornelius, 5, 294 - - Velocipede riding, 74 - - Vesuvius, Ascents of, 22, 33 - - Vibrations, Thoughts on ray-, 193 - - Visits to the sick, 245, 296 - - Volta, Count Alessandro, Meeting with, 22 - - Volta-electric induction, 115 - - Voltameter, 146 - - - W. - - Water, On freezing of, 203 - - Wellington, The Duke of, on practical application of discovery, 248 - - Wheatstone, Sir Charles: - on velocity of discharge, 149, 161; - his electric chronoscope, 192 - - Whewell, Rev. W., Correspondence with, about terms, 116, 144, 145, - 163, 205 - - White, Walter, Reminiscences by, 253, 263 - - William IV., King, 72, 73 - - Wiseman, Cardinal, Meeting with, 297 - - Wollaston, Dr. W. H., Misunderstanding with, 51, 56, 57, 58, 84, 89 - - Woolwich Academy lectures, 66, 101 - - Working, Method of, 66, 242, 247 - - - Y. - - Young, Dr. T., Letter from, 97 - - - Z. - - Zeeman’s magneto-optic discovery, 220 - - - -PRINTED BY CASSELL & COMPANY, LIMITED, LA BELLE SAUVAGE, LONDON, E.C. - - - - -Transcriber’s Notes - - -Punctuation, some hyphenation, and spelling were made consistent when a -predominant preference was found in the original book; otherwise they -were not changed. 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