Biographical memoir of Sir Humphry Davy
Cuvier, Georges, baron, 1769-1832
; '’V' T""' ’ iK-: <'1' v". /■. •y \ ..{,■ vx^;. ’ hs. ' 'r’ » A'' . I '. BIOGRAPHICAL MEMOIR v!» OF SIR HUMPHRY DAVY. BY BARON CUVIER*. From the Edinburgh New Philosophical Journal for July 1833. A CELEBRATED academician, who had risen from the humblest condition to the highest ecclesiastical and literary honours, said, on the day of his admission into the academy, ‘‘ Should there be found in this assembly a young man born with a love for la¬ bour, but wholly destitute of assistance or encouragement, and in whom the uncertainty of his destination weakens his suscep¬ tibility to the excitement of emulation, let the sight of my situa¬ tion at the present moment inspire him with hope.” Nothing indeed can be at once more affecting or encouraging, than to witness merit, by the power of perseverance, surmounting the obstacles which misfortune had opposed to it, and, gradually emerging from obscurity, become at last an object of general notice, and obtain, with the just approbation of all, the advan¬ tages which our societies can confer on those by whom they are merited. Conspicuous examples of this kind are afforded by the two celebrated chemists, with whom I propose to occupy your at¬ tention during the present meeting, both of whom were born in a state almost of entire privation, yet each supported with firm ness the difficulties of his condition. From the time when they » This interesting Eloge of Sir H. Davy, not yet published, was commu¬ nicated to us in proof-sheet, through the goodness of our friend Mr Pentland of Paris. — Edit. S Biographical Memoir of Sir Humphry Davy. had made some progress in science, and their first works were made known to the public, they became the objects of general favour ; were received in the world, and in proportion as their discoveries increased, they advanced to fortune, and were loaded with honours ; no jealous voice interrupted this unanimity of sentiment regarding them, or, if such was ever raised, it w^as not till they had obtained a position in society which sheltered them from its effects, and reduced those who were jealous to the necessity of being only envious Sir Humphry Davy, Baronet, formerly President of the Royal Society of London, Foreign Associate of the Academy of Sciences in the Institute, w^as the son of Robert Daw and Gi ’ace Millet, and was born at Penzance, a small town in the county of Cornwall, the most remote portion of England towards the west, on the 17th day of December 1778. His family is said to have possessed at one period consider¬ able landed property in the parish of Ludgvan, near Penzance ; but Robert Davy, his father, was reduced to a very small farm on the banks of the Boye, called St Michael, from a rock bear¬ ing some resemblance by its situation, and by having a convent upon it, to that distinguished by the same name on the coast of Normandy. With a view to increase his limited income, he exercised in Penzance, for a long period, the profession of gilder and carver in wood ; but not succeeding in his profession, he abandoned it, and soon after died, in 1794, leaving his widow in a destitute situation with five children, the youngest of whom was little more than four years of age. This respectable woman did not, however, lose courage ; occupied incessantly wdth the education of her children, in order to procure the means of sup¬ porting them, she opened a shop, and subsequently kept a lodging-house, for those wdiose health led them to visit this county, which is celebrated above the rest of England for the mildness of its climate. Her eldest son, the young Humphry, turned to the best account the limited means of instruction which this remote county pre¬ sented, and some of his teachers have since pretended to boast * The other individual alluded to, is the celebrated Luis-Nicolas Vauque- lin, who died on the 15th October 1829.— Traxs. s Biographical Memoir Sir Humphry Davy. of a scholar so celebrated ; but he has always said, that if there was any thing original in his ideas, it was owing to the negli¬ gence and indifference of the persons entrusted with his educa¬ tion, who permitted him to indulge, without restraint, in all the caprices of his fancy. Many men of genius, in relating the his¬ tory of their early lives, could make the same observation. That mode of instruction, indeed, which is calculated for the majority, is not easily adapted to those eccentric intellects whose first ideas are superior to those of their companions, and not unfrequently to those of their masters. The exertions used to make them conform to the common method, have only the effect of obstructing their progress. It is fortunate, therefore, both for themselves and for society, that they should be thus neglect¬ ed. Left to himself, Davy occupied his time in hunting, fish¬ ing, and traversing this picturesque country, already attempt¬ ing to celebrate its beauties in verse, for from his infancy he was both an orator and a poet. He had the power of express¬ ing his impressions in a very vivid manner ; and when he en¬ tered the school, his little companions were accustomed to sur¬ round him, and forget every thing else, in listening to the re¬ cital of what he had seen. His reading did not make a less forcible impression on his mind than his observations ; no sooner had a translation of Homer fallen in his way, than he began to compose an epic poem, of which the subject was Diomede ; a composition, says one of his former schoolfellows, very incorrect, and abounding in violations of the established rules, and of good taste, but full of life and varied incident, displaying a richness of invention, and a freedom of execution, which evince a true poet. It was necessary, however, that he should engage in more se¬ rious occupation, and his mother bound him for five years as an apprentice to an apothecary named Borlase, a member probably of the same family as the minister of the parish of Ludgvan, to whom we are indebted for a natural history of the county of Cornwall, and an account of its antiquities, two works which are still of considerable value on account of the documents which they contain. This apothecary, as is always the case in England, likewise practised surgery and medicine. Young A 2 4 Biographical Memoir of Sir Humphry Davy. Davy was often obliged to visit his patients, and convey to them medicines, an occupation quite in accordance with his early ha¬ bits, and which had the effect of rendering him still more ac¬ tive. While traversing this rich country, he recited aloud either Homer’s verses or his own ; for he had already composed many. It was at this time that he wrote his ode on Mount St Michael, and a poem on Mount’s Bay, two of his best verse compositions. The play given to his active faculties by these solitary walks, led him to explore some of the mysteries of me¬ taphysics, and as far as may be judged from some letters and stanzas written at this period, which were afterwards published, but in a very modified form, under the title of Life, he was absorbed in all the abstractions of pantheism, and spoke of God and of the world, like a Bramin, or a professor of Germah phi¬ losophy. But the county of Cornwall is not merely a picturesque coun¬ try ; its primitive rocks, their various relations, the metallic veins which they contain, and deep mines, sunk at a period antece¬ dent to any authentic record, render it a country pre-eminently geological and chemical, and such an individual as we have de¬ scribed Davy to be, could not listen to conversations on the working and uses of metals, the different processes to which they are subjected, and the relations which subsist between them and the rocks in which they are enclosed, without having his attention drawn to those branches of natural science which treat of the structure of the globe, and the nature of the mate¬ rials of which it is composed. A fortuitous circumstance was the means of engaging his youthful mind in active study. Mr Gregory Watt, son of our late Associate, who brought to per¬ fection the steam-engine, and made it an agent which will change the entire aspect of society, was sent to Penzance on ac¬ count of an affection of his breast, and lodged in the house of Mrs Davy. The young apothecary, attracted by his handsome figure and elegant manners, became desirous of gaining his friendship ; but the English are backward to form friendships, especially when there is a difference of fortune or rank. To re¬ commend himself to notice, Davy entertained Mr Watt with chemistry, of which he had already acquired a slight and prac¬ tical knowledge in the house of his master, although it did not 5 Biographical Memoir of' Sir Humphry Davy. fit him to converse on the subject with one well versed in its principles. Some one to whom he mentioned his intention, pro¬ cured for him an English translation of Lavoisier’s chemistry. In two days he had made himself completely master of it, and it is very remarkable, that, in entire ignorance of the objections which Priestley and others of his countrymen had raised against the theory advanced in that celebrated work, he declared that there occurred to him another explanation of the phenomena ; and he began seriously to engage in developing it. The ani¬ mated discussions which he had with Mr Watt on this subject, had only the effect of confirming his resolution ; the poet and the metaphysician decided at once on becoming a chemist. The state of his affairs was such, as to render it no easy matter to procure even the requisite instruments ; but in this, as in every thing else that he undertook, his courage and perseve- ranee surmounted all obstacles. Old tobacco-pipes, and a few glass-tubes purchased from a travelling vender of barometers, formed his first apparatus. The surgeon of a French ship, stranded near Land’s End, shewed him his instruments, and having observed a utensil of very common and familiar use among us, the form of which apparently differs in the two countries, he conceived the possibility of rendering it the princi¬ pal piece in a pneumatic machine ; and to this purpose, so dif¬ ferent from that for which it was intended, it was in reality ap¬ plied. It is thus that, in the case of many great men, priva¬ tion has proved the most useful master. The experience which he acquired on this occasion was never afterwards lost. During his whole life, Mr Davy never wanted a resource in his investigations ; the simplicity of his apparatus was always as remarkable as the originality of his experiments, and the elevation of his views ; and even when he travelled into places the most remote from scientific aid, he was never more at a loss to bring to the test of experiment any new idea that occurred to him, than he was when he commenced his first la-*, hours in the shop of his master at Penzance. After some further exercise, he took from his own neighbour¬ hood the subject of his first experiment. He wished to ascer, tain with what kind of air the vesicles of fuci are filled, and de¬ termined, with as much precision as the most accomplished che- 6 Biographical Memoir of Sir Humphry Davy, mist could have done, that marine plants act on the air in the same manner as land plants. This was in 1797, when he was not quite eighteen years of age. About this time, Dr Beddoes, who had been obliged by politi¬ cal dissensions to leave the Chair of Chemistry in the University of Oxford, came to establish himself at Bristol, where he formed, with the assistance of the family of the celebrated Wedgwood, an establishment called The Pneumatic Institution, the principal object of which was to try the action of various gases on dis¬ eases of the lungs ; he commenced at the sarnie time a periodi¬ cal collection, entitled Contributions from the Western Provinces, in which he inserted the researches of the physicians and che¬ mists of that part of England. It was to this individual that Davy addressed his essay, and Beddoes, surprised at finding a young apothecary of Penzance capable of such investigations, was very anxious to attach him to his institution. For this purpose, it was necessary to dissolve the contract of apprenticeship which he had formed with Borlase, according to the somewhat Gothic practice which prevails in Great Britain. Mr Davies Gilbert now President of the Boyal Society, under¬ took the negotiation, which was speedily completed ; for the apothecary, who apparently cared but little for scientific dis¬ coveries, and still less for metaphysics and poetry, shewed no reluctance to restore to liberty a youth whose qualities he re¬ garded with no favourable eye, although destined to become so soon after the light of chemistry, and the honour of his country *. But Beddoes estimated men by a different standard ; and speedily discerning the intellectual qualities of his new assistant, he did not employ him merely in that capacity, but entrusted him with his laboratory, and permitted him to perform all the experiments he judged necessary to extend his knowledge of gases, and gave the use of his amphitheatre to deliver lectures. * It is due to the character of Davy’s first master to state, that the rea¬ diness with which he surrendered the indenture, originated in motives en¬ tirely the reverse of those here ascribed to him. It was because he appre¬ ciated the talents of the young chemist, and from a wish to promote his ad¬ vancement, that the arrangement was effected with so much facility. See Paris’ Life of Sir H. Davy, i. 55.— Trans, Biographical Memoir of Sir Humphry Davy, 7 It was in the Pneumatic Institution that Davy discovered, in 1799, the properties of nitrous oocide gas, or as it is now called, protoxide of azote, and the extraordinary effects it pro¬ duces on certain organizations Many persons on inhaling it experience only uneasiness and symptoms of asphyxia ; others are affected with decided asphyxia ; but in some it produces intoxication of a peculiar kind, exciting sensations of the most delicious nature, and so superior to all other kinds of pleasure, that they would permit themselves to die in that state without making the slightest effort to escape from it. It is easy to imagine the eagerness with which this new man¬ ner of producing intoxication was received in a country where the old method was practised to a much greater extent than at present, as it led to the hope of an agreeable variation in an en¬ joyment become too monotonous ; the name of the young che¬ mist of Penzance was therefore speedily popular throughout the three kingdoms. In order to do him full justice, however, it must be added, that the courage which he had shewn was not less remarkable than the singularity of the discovery. He gives a fearful de¬ scription of the state into which it threw him. The loss of vo¬ luntary motion did not at first diminish his sensations ; he saw and heard all that was going on around him ; but in proportion as the species of asphyxia increased, he lost the power of per¬ ceiving external things ; a crowd of images rose in his mind, and he seemed to be making discoveries, and forming theories of the most sublime description. But let it not be supposed that this mode of intoxication more than any other can teach any thing new. When a friend snatched from him the receiver of the dangerous gas, his first words were only the old formula of idealism, Nothing exists hut thought ; the universe is composed only qf impressions arid ideas of pleasure and pain. This system had been long the subject of his thoughts. He made a still more dangerous experiment by respiring carbonic gas, but it produced only pain and depression ; and it is not impro- * Researches, chemical and philosophical, chiefly concerning nitrous oxide and its respiration. 8vo. London, 1800. Translated into French, Annates de CMmie, tom. xli. p. 305 ; xlii. p. 33 and 276 ; xliii. p. 97 and 324 ; xliv. p. 43 and 218 ; xlv p. 97 and 169 ; also ixiio BlbliotJieque Britannique, tom, xix. XX. xxi. 8 Biographical Memoir qf Sir Humphry Davy. bable that these rash attempts contributed to produce that sud¬ den change in his constitution which terminated in his prema¬ ture death. At this period Bristol was filled with enthusiastic young men, fond of novelty, and forward to express their sentiments, whose speeches, in the midst of those dissentions which the French re¬ volution had excited in England, caused this town to be regarded as the principal seat of democracy. These youths, in concert with their correspondents in diffe¬ rent parts of the kingdom, had formed a design to raise their friends to situations which were most likely to make them the objects of public favour, and in prosecution of their plan, they resolved to use their efforts to place the young professor in a sphere of wider influence. Our former associate, Count Rum- ford, had established in London the Royal Institution, designed to spread among the higher classes of society the useful dis¬ coveries of science. Being naturally of an unaccommodating dis¬ position, he had already quarrelled with Dr Garnet, his pro¬ fessor of chemistry ; and it was resolved to propose Davy, who was urged to come forward and be presented to him. Every one will remember that, with all his great and noble qualities. Count Rumford was[not distinguished for affability; the almost infantine appearance of the candidate, who always looked younger than he really was, joined to manners somewhat provin¬ cial, and the remains of a Cornwall accent, rendered the Count even more repulsive than usual, and Davy’s timidity, increased by such a reception, was little calculated to remove the effect of his first appearance. The persons by whom he was introduced had to employ much art and solicitation to obtain permission for him to give some lectures, in a particular apartment of the house, on the properties of gases ; but more than this was not needed. From the first, the variety of his ideas and their inge¬ nious combinations, the warmth, vivacity, perspicuity, and ori¬ ginality of their exposition, all the interest which the united talents of the poet, the orator, and the philosopher can confer on the teaching of chemistry, had the effect of enchanting the small number who had ventured to come and hear him. They immediately spoke of him with so much enthusiasm, that the place of meeting was unable to accommodate the influx of auditors. Biographical Memoir of Sir Humphry Davy* 9 and his lectures had to be transferred to the great amphitheatre of the establishment. The Royal Institution was at that time supported by all that was most elevated in Great Britain, both in birth and in intel¬ lect ; ladies of the highest rank attended the lectures, as well as the most distinguished noblemen and youths of the country. The youth of a professor who had scarcely advanced be¬ yond the age of boyhood, his handsome figure, and ingenious manners, contributed not less than his lively eloquence to con¬ ciliate the affection of such a public. In a short time he be¬ came so much in fashion, that not an evening party appeared complete when he was not present. This was such an entire revolution in his condition, that he required not less courage to continue his labours in this sudden prosperity, than he needed to commence them in the midst of misfortune. Some even pre¬ tend that he permitted himself to be more elated by his recep¬ tion in the great world, than was due to his genius and circum¬ stances. But what young man of twenty would have better resisted such a temptation ? He did not at least renounce science ; for in the midst of the pleasures which it was so natu¬ ral for one of his age to wish to enjoy, he ceased not for a mo¬ ment to multiply the titles which had been the means of obtain¬ ing them for him. But who ought to have experienced greater happiness ? From the time of his first regular course, which was given in May 1801, a continued series of lectures, experiments, and discove¬ ries, which succeeded each other with unparalleled rapidity, and which have elucidated the most important branches of Physics and Chemistry, essentially modified their doctrines, and led to the most beneficial and unexpected applications to the wants of society, secured for their author the admiration of the civilized world, and the gratitude of his country. Nominated a member of the Royal Society in 1803, and appointed secretary in 1806 ; commissioned by the Board of Agriculture to teach the appli¬ cation of Chemistry to that branch of public economy ; united in 1812 to a lady of great wealth, and high intellectual endow¬ ments ; and honoured, the same year, with knighthood, be¬ ing the first person so distinguished by the Prince Regent ; created Baronet in 1818, when this Prince mounted the throne ; 10 Biographical Memoir of Sir Humphry Davy, and, finally, elected to the distinguished station of President of the Royal Society in 1820, on the death of Sir Joseph Banks, by a majority of two hundred against thirteen, an of¬ fice which he continued to hold for seven years :■ — the young apprentice of Penzance enjoyed without interruption all the ho¬ nours which a great state could confer on those who do it honour. These marks of esteem were confirmed by the approbation of foreigners. Crowned by the Institute in 1807, when the war with England was at its height ; associated with that body in 1817 ; called upon in like manner to enjoy the honours of all the celebrated academies ; Mr Davy had to boast of the appro¬ bation of Europe as well as of his own country. But our na¬ ture does not admit of perfect happiness in the present world ; and when ail around us is prosperous, we not unfrequently carry within ourselves the poison that embitters our existence. In the exposition which I am about to give of Mr Davy’s la¬ bours, continued without interruption for upwards of twenty- five years, and published in sixty different memoirs and papers, it will be understood that I can attend only to the principal re¬ sults and fundamental discoveries. I shall, therefore, pass ra¬ pidly over his first experiments, made in the Royal Institution in 1803, toMetermine the proportions of tannin in the different substances] used in tanning Those of the following year (1802), on the different combinations of azote with oxygen, that is to say, on nitrous oxide and the nitrous gas now named protoxide and deutoxide of azote, and on the proportions of their elements, as well as those of hydrogen and azote, which are^acquiring a more general importance in Chemistry, were the natural consequences of his first observations on nitrous gas, and the invention of a new eudiometer resulted from them-j". A solution ol* muriate, or of sulphate of iron, impregnated with nitrous gas, was found to absorb oxygen with greater facility than any other substance. * An account of some experiments and observations on the constituent parts of certain astringent vegetables, and on their operation in tanning— Roy. Soc. London, 24th Feb. 1803 ; Phil. Trans, xcxiii. p. 233 ; Nicholson'' s Journal, v. p. 256. •f An Account of a New Eudiometer.— Journal, 4to, vol. v, p, 175; Biblioth. Brit. vii. p. 246 ; Ann Chim. tom. xlii. p. 301, Biographical Memoir of Sir Humphry Davy, 1 1 We are unable to bestow much time on his mineralogical discoveries, although they are doubtless far from unimportant. In 1805, his analysis of a stone from Devonshire, which had been named wavellite, furnished to this science a new species. It is a combination of pure alumina with water The same year he published a new method of analyzing stones containing a fixed alkali, by means of the boracic acid He proved more evidently than had been previously done, and contrary to his own conjectures on the subject, that the diamond produces on combustion only pure carbonic acid In 1822, he proved that iron and silex are dissolved in the thermal waters of Lucca §. Rock-crystal and other stones often contain in cavities in their interior gases and liquids ; and as these sub¬ stances must have been inclosed at the time of their formation, a knowledge of their nature was not without interest in the an¬ cient history of the globe. Mr Davy found them to consist of pure water and pure azotic gas J. Much light was likewise thrown on many branches of physics by the observations made in the course of his researches. The nature of the changes of colour produced by heat on the surface of steel ^ ; the formation of mists over the surface of rivers ; the application that may be made of liquids formed by the con- * An Account of some analytical experiments on a mineral production from Devonshire, consisting principally of alumina and water. — Roy. Soc. Land. 28th Feb. 1805 ; Phil. Trans, xcv. p. 155 ; Biblioth. Brit, xxx. p. 303 ; Ann. de Chimie, lx. p. 297* * * § ** ■{• Roy. Soc. Lond. 16th May 1815; Phil. Trans, xcv. p. 231 ; Annales de Chimie^ tom. lx. p. 297* $ Some experiments on the combustion of the diamond and other carbona¬ ceous substances.— i2oy. Soc. Lond. 23d June 1811 ; Phil. Trans, civ. p. 557 ; Ann. de Chimie et de Physique, i. p. 16 ; Bihl. Britan, vol. Ivii. p. 124. § Memoria sopra di un deposito trovato nei Bagni di 'LiUcc.a.^Atti della Real. Acad. Neapolit. v. ii. p. 9 ; Ann. de Chimie et de Physique, tom. xix. p. 194. 11 On the state of water and aeriform matter in cavities found in certain crystals — Roy. Soc. Lond. 13th June 1822; Phil. Trans, v. cxii. p. 367 ; Ann. de Chim. et de Phys. tom. xxi. p. 132. ^ Ann. of Philosophy, vol. i. p. 131 ; Bill. Brit. vol. Iv. p. 157. ** Some observations on the formation of mists in particular situations —. Roy. Soc. Lond. 25th Feb. 1819 ; Phil. Trans, vol. cix. p. 123; Ann. de Chim. et de Phys, xii. 195. 12 Biographical Memoir of Sir Humphry Davy. densation of gases as mechanical agents ; finally, the colour of the water of rivers and of the ocean f ; were subjects that at¬ tracted his attention, and produced instructive and interesting papers. Particular mention ought to be made of the course of lectures which he delivered before the Board of Agriculture in 1803, and which were published in 1813 It was thus that a young man of twenty-two, who had no practical experience of the subject, unexpectedly enlightened the proprietors and most experienced cultivators in Great Britain. Such occupation, however, as we have been alluding to, may be said to have formed only a kind of diversion from his severer studies. His experiments on the decomposition of bodies by galvanic electricity were of a superior order, and it was to them that he owed his sudden elevation, by the unanimous voice of Europe, to the rank of one of the first chemists of our age. No one will dispute that there was never displayed, in such a length¬ ened investigation, a greater degree of perseverance, method, and precision ; and rarely have these qualities been crowned with more brilliant success. An observation casually made by Galvani in 1789, in which he had seen the parts of a dead animal become convulsed when a metallic communication was established between a nerve and the muscle, had excited the attention not only of the learned but of the vulgar : some believed that they saw in it the explanation of all the vital phenomena, and the means of recalling even the dead to life. Volta referred these facts to their true cause, viz. the electricity produced by the contact of two metals; and, in his endeavours to render the influence of the metals more considerable, he increased the number of the plates, and se¬ parated them by others of less conductive power ; thus con¬ structing his famous pile, the constant source of an electricity * Roy. Soc. Lond. 27th April 1823; Phil. Trans, v. cxiii. p. 193; Ann. de Chim. et de Phys. tom. xxv. p, 80. •j- Salmonia (2d edit.), p. 316 ; Bibl. Univ. tom. xl. p. 114. $ Elements of Agricultural Chemistry, in a Course of Lectures for the Board of Agriculture, 4to and 8vo, Lond. 1813. Translated into French, 12mo, Paris 1820, and into German, by F. Wolf, with additions by A. Thaer, 8vo, Berlin 1814. Biographical Memoir of Sir Humphry Davy. 1 3 which is continually renewed. Scarcely had physicians become acquainted with this new and admirable instrument, than they wished to try its effects on every kind of substance. About tlie year 1800, Messrs Carlisle and Nicholson, intro¬ ducing into the water metallic wires corresponding to the two poles of the pile, saw with surprise that oxygen was evolved near the positive thread, and hydrogen near the negative one. The same year, perhaps before them, Ritter, in Germany, had arrived at a more precise result, by placing water in two separate vessels, but communicating with each other by means of sulphuric acid: oxygen and hydrogen were produced indefinitely, each at its pole. He thence concluded, not that the pile decom¬ posed water, but that the two gases are only water combined with the two kinds of electricity. When an animal fibre, or even the fino-ers, formed the communication between the two vessels, muriatic acid also appeared at the positive wire ; and some had even concluded, from this circumstance, that this acid was formed of hydrogen less oxygenated than water. Alkalies likewise appeared, of different kinds, according to the circum¬ stances in which the operation was performed. In 1803, two Swedish chemists, Messrs Hisinger and Berze¬ lius, by repeated experiments, had ascertained the fact, that the decomposing action of the pile extends to bodies of every kind ; that it invariably causes acids and oxygenated substances to ap¬ pear towards the positive pole, and alkalies towards the negative one ; thus opening a way to the explanation of these different anomalies. Mr Davy had observed with attention the progress of these experiments, and, even in 1800, and under the eye of Beddoes, he had operated on water, placed in two separate vases, but em¬ ploying a strip of bladder as the means of communication. In this experiment, muriatic acid likewise appeared*. In 1801 he had made known to the public a kind of pile, differing in some respects from that of Volta, in which a single plate of metal alternated with two liquids-|*. In 1802, he had ope- * Notice of some observations on the causes of the galvanic phenomena, and on certain modes of increasing the powers of the galvanic pile of "V olta. — NicholsoTvS Journal^ 4to, vol. iv. p. 337, 380, and 394. •f An account of some galvanic combinations formed by the arrangement 14 Biographical Memoir of Sir Humphry Davy» rated on various liquids with a very powerful pile, and ob¬ served many singular disengagements of gas. He at last en¬ gaged in a series of profound investigations, which he pro¬ secuted with the utmost perseverance for some years, and de¬ finitely established the theory of this new order of phenome¬ na. The result was published in 1806 % in a memoir, en¬ titled Bdkerian Lectures ^ so called because they were deliver¬ ed in one of these foundations which are pretty numerous in England, the object of which is to direct the attention of the learned to certain special subjects in which the founder felt an interest. After the most minute precautions, he succeeded in demonstrating that, when water is pure, it is decomposed by elec¬ tricity into gaseous matter alone, viz. into oxygen and hydrogen, in the proportions in which they enter into its composition. Sub¬ mitting to the same agent bodies of different kinds, he carried to the highest degree of generalization the law of Hisinger and Berzelius ; and, even reverting to the principle on which it was founded, he came to the conclusion that chemical affinity is nothing else than the energy of' opposite powers of electricity — a conclusion which, combined with another law established in 1804 by Mr Dalton, on definite proportions, afforded to Berzelius prin¬ ciples for the establishment of an entirely new system of chemistry and mineralogy. It was for this great and important service that the Institute, at its public sitting in January 1808, awarded to Mr Davy the prize founded for the advancement of galvanism, an honour which has not since been conferred on any one except M. Oer- stedt for his brilliant discovery of the relations between galvanism and electricity. Soon after, Mr Davy, by prosecuting the same views, obtained a success still more flattering, because exclusively his own ; I allude to the discovery of the metallic nature of fixed alkalies. For a long time chemists had been struck with of single metallic plates and fluids, analogous to the new galvanic apparatus of Volta — Roy. Soc. Lond. 18th June 1801 ; PMl. Trans, vol. xci. 397; Bi- hlioth. Brit. vol. xvii. p. 237* * On some chemical agencies of electricity. — .Roy. Soc. Lond. 20th Nov. 1806; Phil. Trans, vol. xcvii. p. 1, 1807 ; Ann. de Chimie, tom. Ixiii, p. 172 and 225; Journal de Physique, t. Ixiv. p. 421 ; Biblioth. Brit. t. Xxxv. p. 16. 15 Biographical Memoir of Sir Humphry Davy. the analogies of the fixed alkalies with alkaline earths, and of the latter with metallic oxides, and Lavoisier had even announced the possibility of these earths being oxides, incapable of being reduced by the ordinary means. With respect to the fixed al¬ kalies properly so called, whatever conjectures had been formed as to their composition, results from some combinations with azote ; the analogy with ammoniac had led to this idea ; but in science the most happy conjectures are unavailing, if not con¬ firmed by experience. Mr Davy being in possession of such a powerful means of de* composition as the pile, did not despair of resolving the import¬ ant problem. After having tried it without success on some aqueous solutions, he took potash sufficiently moistened to make it serve as a conductor, and having placed it in the circle of a powerful battery, the positive side produced a violent efferves¬ cence, while at the negative side there appeared small globules, resembling quicksilver in colour and lustre, but so combustible that they were covered almost while they formed, with a white crust of potash, and which, when thrown upon water, remained on the surface, and burned with a bright flame and considerable heat ; it was the same upon ice, and it looked as if he had re¬ covered the wild fire so famous in Byzantine history, to which it is probably owing that Europe is not at the present day under the influence of Mahometanism, The same phenomena pre¬ sented themselves with soda, and whatever were the conductors, the produce of the combustion w^as always potash or soda; an envelope of naphtha was the only means of preventing these metallic globules from attracting oxygen, so as to counteract their tendency to combustion. It was in vain that some con¬ tended that these new substances were combinations of hydro¬ gen, or even carbon, with the alkalies; rigorous analysis speedily exposed the error of such an hypothesis, and it remained demon¬ strated that potash and soda resulted from the combination of oxygen with bases resembling metals in their external charac¬ ters, but infinitely lighter, and having an infinitely stronger at¬ traction for oxygen. Potash contains 84 centiemes, and soda 76 centiemes, of metal. These bases, which are as perfect con¬ ductors of heat and electricity as the other metals, become soft at 12° of Reaumur, and at 30° become liquid like mercury, and 16 Biographical Memoir of Sir Humphry Davy. evaporate at a red heat* * * §. Klaproth, the first individual in our days who discovered a new metal, wished to question their metal¬ lic quality on the ground of their specific lightness ; and in fact all the known metals are heavy, but in very different degrees. Tellurium, for example, is four times lighter than platina, and there is no reason why sodium and potassium^ (the names by which Mr Davy distinguished the new substances) although six times lighter than tellurium, should be excluded from that class of substances to which they belong by all their other attributes. This grand discovery was made in 1807, and formed the subject of the Bakerian Lecture for the month of November of the same yearf. It could not fail to lead a mind like Davy’s to new researches and new ideas ; he tried the same process on many other earths, and Berzelius did the same, proving that they must all be regarded as oxides. The great Swedish chemist, having electrified negatively some mercurv in contact with a solution of ammonia, succeeded in producing an amalgam ; and Mr Davy, who had arrived at the same result by more simple means:|;, observed the mercury be¬ come solid, and lose three-fourths of its specific gravity, by the addition of a quantity of gas, scarcely equivalent to Q of its weight ; he was led, therefore, to think that the ammonia had likewise a base, and that perhaps the azote and hydrogen, of which it is composed, are themselves metallic oxides §. Bising * The more correct statement is this Potassium at 50® Fahr. is soft and malleable, but melts at 136|°; sodium is soft and malleable at the common temperature of the atmosphere, and melts at 194° F. On some new phenomena of chemical changes produced bj electricity, particularly the decomposition of fixed alkalies, and the exhibition of the new substances which constitute their bases, and on the general nature of alkaline bodies. _ Roy. Soc. Lond. 12th and 19th November 1807. PMl. Trans, of Lon¬ don, vol. xcviii. p. 1. Ann. de Chimie. Ixviii. p. 203-225. Biblioth. Brit. vol. xxxviii. p. 3. + An account of some analytical researches on the nature of certain bodies, particularly the alkalies, phosphorus, sulphur, carbonaceous matter, and the acids hitherto undecompounded ; with some general observations on chemical theory. Roy. Soc. Lond. 15th December 1808. Phil. Trans, vol. xcix. p. 39; Ann. de Chim. tom Ixxii. p. 244, and Ixxiii. p. 5. Biblioth. Brit. vol. xlii. p. 27. Journ. de Phys. tom. Ixix. p. 360. § New analytical researches on the nature of certain bodies. 1st, Further inquiries on the action of potassium or ammonia, and on the analysis of am- Biographical Memoir of Sir Humphry Davy. 17 to the highest generalities, he took into account nothing in na ture but oxygen and unknown bases ; varying even his explana¬ tions, as in algebra, in which a diversity of forms may lead to the same result, he inquired whether hydrogen might not be the principle of metallization, and whether oxides might not be re¬ duced to combinations of bases with water, thus reverting, so to speak, to the ancient hypothesis of phlogiston, under another form. This tendency may be observed in many other of Mr Davy’s memoirs, and perhaps he may be suspected in this of a little national jealousy. But although unsuccessful in over¬ throwing the French theory of combustion, he adduced at least such a striking exception, that instead of longer retaining the character of a general explanation, it became applicable only to particular cases of phenomena which required an explanation of a more elevated nature ; and this forms the third and most im¬ portant of his discoveries. It was already known by the expe¬ riments of Bertholet, that sulphuretted hydrogen, which does not contain oxygen, acts like an acid ; oxygen, therefore, is not always the principle of acidity. On the other hand, the experi¬ ments of Mr Davy went to prove that it is the principle of alca- linity as well as of acidity, and thus its name was not justified by its nature. It was soon to be shewn that hydrogen has the power of producing acids, not less than oxygen. For a long time chemists had attempted in vain to discover the base of muriatic acid ; but after the explanations proposed by Bertholet, they supposed that this other acid, so cele¬ brated for the uses to which it is applied in the arts, and which is obtained by causing muriatic acid to pass over oxide of man¬ ganese, and named dephlogisticated muriatic acid by Steele its discoverer, resulted from the combination of muriatic acid with oxygen of the oxide ; it was consequently named ooeyge^ nated muriatic acid, and nothing appeared more simple than to extract from it the muriatic acid, by depriving it of this oxy¬ gen with which it was believed to be surcharged. MM. Gay- Lussac and Thenard attempted it, but could never succeed with¬ out the addition of water or at least of hydrogen. This pheno- monia. 2d, On sulphur and phosphorus. 3d, On carbonaceous matter. 4th, Muriatic acid. Roy. Soc. Lond. 2d February and 16th March 1809. Phil. Trans, vol. xcix. p. 450. Biblioth. Brit. vol. xliv. p. 42. B 18 Biographical Memoir of Sir Humphry Davy. menon appeared to them remarkable ; water, they said, is an ingredient necessary to the formation of muriatic acid ; but how does it happen to adhere so forcibly, that no means are sufficient to disengage it ? May it not be only by one of these elements that it concurs in forming this acid ? and may not the oxygen which is disengaged during the operation, and which is suppos¬ ed to proceed from the oxygenated muriatic acid, be simply an¬ other element of w^ater ? Thus, neither oxygenated muriatic acid, nor common muriatic acid, would contain oxygen. 