Davy, Sir Humphry
, baronet (17781829), chemist and inventor
, was born on 17 December 1778 at 4 The Terrace, Market Jew Street, Penzance, Cornwall, the eldest of five children of Robert Davy, a woodcarver, and his wife, Grace Millett. His father was descended from a line of yeomen, or even gentlemen, but the only property he owned was a small farm at Varfell in Ludgvan, overlooking St Michael's Mount. His mother also came from an old Cornish family. When he was nine, the family moved from Penzance to Varfell, and during school terms Humphry boarded with his godfather John Tonkin, an apothecarysurgeon. After learning to read and write from old Mr Bushell, he was sent at the age of six to the grammar school at Penzance, where the schoolmaster, the Revd Mr Coryton, made learning a pain (notably by twisting the boys' ears). Here Davy enjoyed much idleness, which he later felt was fortunate for him, the source indeed of his talents and their application. He became intellectually self-propelled.
Childhood, education, and apprenticeship
While at school Davy discovered a talent for writing verses and as a story-teller, and took up fishing and shooting. His first experience of chemistry was when he made fireworks with his sister. Then, at the beginning of 1793, he went at Tonkin's expense to the grammar school in Truro, the county town of Cornwall. There the headmaster was Dr Cardew, whom Davy considered far better than Mr Coryton, but who failed to discover any extraordinary abilities or even any propensity to scientific pursuits. Davy left school in December 1793, just before his sixteenth birthday, and lived with Tonkin, following an informal course of self-education. His father suffered from heart disease and in December 1794, at the age of forty-eight, he died, leaving his widow an income of £150 a year and debts of £1500.
Mrs Davy moved back to Penzance and, with a French refugee, opened a milliner's shop; by 1799 the debts were paid, she had received an unexpected legacy of £300, and she gave up the shop. Davy had told her not to grieve, for he would do all in his power for his brother and sisters, and on 10 February 1795 he was apprenticed to Bingham Borlase, like Tonkin an apothecarysurgeon and prominent citizen of Penzance. He continued with his programme of self-education, which, as well as the chemistry, botany, and anatomy needed for part of his profession, included physics and mechanics.
Davy was a satisfactory apprentice, and clearly also a rather dreamy young man, declaiming poetry in the wild outdoors but also reading Locke, Berkeley, David Hartley, and other philosophical authors. In 1799 his first poems were published by Robert Southey in the Annual Anthology
; the best-known of these, The sons of genius, was written in 17956 and is suffused with both the sublime and the beautiful. Delighting in the rough precipice, in ancient Greece, and in science (then called natural philosophy), Davy saw himself as a son of both nature and genius, hoping:
To scan the laws of nature, to explore
The tranquil reign of mild Philosophy;
Or on Newtonian wings to soar
Through the bright regions of the starry sky. (Collected Works, 1.26)
M. Dugast, a French refugee priest from La Vendée, taught him French, but Davy, who had no ear for music, never learned to speak the language without a strong accent.
Davy was, nevertheless, equipped by 1797 to read Lavoisier's Traité élémentaire de chimie
in French. This book appeared in 1789, and its author and his contemporaries saw it as revolutionary. Its beautifully clear exposition of the idea that oxygen from the air is the crucial agent in combustion, and its new and logical nomenclature, seemed to make chemistry a coherent, and also a French, science. Davy was to make two important amendments to Lavoisier's scheme, and indeed much of his work can be seen as directed against Lavoisier and French hegemony. Sulphuric, nitric, and other acids contain oxygen and it seemed a reasonable inference that this element was the cause of acidity: accordingly, its name (from ancient Greek) means acid-generator. In addition, Lavoisier saw definite quantities of heat being involved in chemical reactions and in changes of state, and for him heat was a weightless chemical element, caloric. Liquids and gases were thought to be compounds of solid elements with caloric: oxygen and hydrogen were thus for Lavoisier not yet known in elementary form.
Davy began his chemical career by propounding a different idea of heat, and crowned it with a different view of acidity. He aspired to be the Newton of chemistry, and he was attracted to the older view of Bacon, Locke, and Newton that heat was the motion of the particles of matter. Perhaps with adapted instruments from a shipwrecked French surgeon, and certainly with help from Robert Dunkin (a Quaker saddler turned instrument maker), Davy began experiments, notably melting lumps of ice by friction in rubbing them together to prove his theory of heat against Lavoisier's. Swinging one day on Borlase's gate, he caught the attention of Davies Giddy (who changed his name to Gilbert in 1817), a member of parliament with scientific interests, who became his patron and was later his successor as president of the Royal Society. He offered Davy the use of his library and introduced him to Dr Edwards, who later lectured on chemistry at St Bartholomew's Hospital in London. Davy was transported with delight to see Edwards's laboratory, which contained apparatus he knew about only from descriptions and engravings.
As an undergraduate in Oxford, Giddy had attended lectures on chemistry given by Thomas Beddoes, politically a radical whose Oxford career was brought to an end in the reaction against the French revolution. Beddoes visited Cornwall to study its minerals with Giddy at a time when he was proposing to set up in Bristol, with backing from Josiah Wedgwood and help from James Watt, a clinic where the new factitious airs, gases discovered by Joseph Priestley, would be administered to the sick. Wedgwood's son Thomas and Watt's son Gregory both suffered from tuberculosis. In the winter of 17978 Gregory Watt was sent to Cornwall for its mild climate, and boarded with the Davys, where he was excited by Humphry's offer to demolish the French theory of heat. In April 1798 Beddoes received through the young Watt, and with Giddy's support, Davy's essay on heat and light, and in 1799 published it.
Davy later repudiated this essay, as infant chemical speculations, but it helped make his name. While he thought heat was motion, he believed that light was a substance entering into chemical unionLavoisier's oxygen gas should thus be called phosoxygen. His essay included work on what is now called photosynthesis, and he was the first to establish that pondweeds release oxygen in sunlight; he also connected light with electricity, and with life. The essay ended with the hope that chemistry, in its connection with the laws of life, [will] become the most sublime and important of all sciences (Collected Works
Beddoes needed an assistant and with Giddy persuaded Borlase to release Davy from his indentures; Tonkin was furious that a safe career as a medical practitioner should be abandoned for such quackery, but on 2 October 1798 Davy set out from Penzance for Clifton on his great journey into science and social mobility. Two days later Giddy met him for breakfast at Okehampton, where the mail coach arrived beribboned, bearing news of Nelson's victory over the French on the Nile.
Bristol: laughing gas
Bristol was a wealthy city of merchants, much more sophisticated than Cornwall with its mines and fisheries. Beddoes's Pneumatic Institution was eventually set up at Hotwells, in Dowry Square. Finance came from Wedgwood, and also from the coal-owning MP William Henry Lambton, whose sons boarded with Beddoes and got to know Davy; John, the elder, later became earl of Durham. Beddoes's wife was sister to Maria Edgeworth, and they moved in literary circles. Davy soon met Joseph Cottle, who was publishing his essay and also work by William Wordsworth, S. T. Coleridge, and Southey. By early 1799 Davy was doing experiments on gases, following up Priestley's researches, in the well-equipped laboratory.
Davy took up the implausible published claims of a prominent American, Samuel Mitchill, that combinations of oxygen and nitrogen must be poisonous, and that nitrous oxide must be the worst of them, a veritable septon or principle of contagion. Davy tried some experiments with it, and by April could prepare it in sufficient quantity, and pure enough, to breathe itand thus discovered its effects as laughing gas. The experiment was one of a series of risky trials: with nitric oxide the effects were very painful, and with carbon monoxide nearly fatal, but here was pure pleasure. Davy wrote excellent first-hand accounts of the anaesthetic action of the gas and of its exhilarating effect as he awoke from semi-delirium:
My emotions were enthusiastic and sublime; and for a minute I walked about the room perfectly regardless of what was said to me. As I recovered my former state of mind, I felt an inclination to communicate the discoveries I had made during the experiment. I endeavoured to recall the ideas, they were feeble and indistinct; one collection of terms, however, presented itself: and with the most intense belief and prophetic manner, I exclaimed … Nothing exists but thoughts!the universe is composed of impressions, ideas, pleasures and pains! (Collected Works, 3.390)
Coleridge became an enthusiastic friend of Davy and collaborated in these experiments; impressive testimony from him and many others on the effects of the gas, with careful chemical analyses of the oxides of nitrogen, were collected into Davy's first book, Researches, Chemical and Philosophical, Chiefly Concerning Nitrous Oxide
, published in 1800. He recommended the gas as an anaesthetic in minor surgery, but neither he nor anybody else pursued this idea at the time.
Other work Davy did in Bristol included the discovery of silica in grasses, and some researches in electricity. Alessandro Volta had found that when dissimilar metals are piled up with damp pasteboard between them an electric current flows, and his pile is the ancestor of today's electric batteries. This discovery Davy later referred to as an alarm bell: it set him, and many other men of science, off in a new direction. He found that acid in the pile makes it more effective, and believed that its action (which Volta attributed to mere contact) must depend upon a chemical reaction. He made piles with charcoal replacing one metal, and with two fluids and one metal. These were described in the first of his papers to be published in the Royal Society's Philosophical Transactions
, in 1801.
Meanwhile, Davy also kept up other interests, pursuing his science in bursts of creative activity. He recorded a mystical experience of sympathy with nature, when he would have felt pain in tearing a leaf from a tree. His notebooks, begun from both ends, are full of fragments of verse and prose, doodles, good resolutions, and scientific experiments and jottings. He was asked by Wordsworth to oversee the printing of the second edition of Lyrical Ballads
and to correct the punctuation; later he visited the Wordsworths at Dove Cottage. He also saw through the press Southey's epic, Thalaba
. His work on the oxides of nitrogen, where different compounds of the same two elements have very different properties, and on the electric battery, convinced him that nature was no clockwork, but dynamicalbased upon polar forces in equilibriumand not to be explained in material terms alone. He passed through a brief period of religious scepticism to a settled dualism, and a pantheism expressed in a rhapsody of uncertain date:
Oh, most magnificent and noble nature!
Have I not worshipped thee with such a love
As never mortal man before displayed?
Adored thee in thy majesty of visible creation,
And searched into thy hidden and mysterious ways
As Poet, as Philosopher, as Sage? (Fragmentary Remains, 14)
The Davy family was Anglican, but he seems to have preferred to worship God outdoors rather than belonging to a particular congregation.
The Royal Institution: useful knowledge
In September 1800 Davy wrote to his mother about brilliant prospects, and in January 1801 was formally invited by Count von Rumford to a post at the Royal Institution, recently founded in London. Beddoes put no obstacles in his way, and after visiting London in February, Davy moved there to start his new duties in March. Rumford had persuaded landed gentlemen, seeking more efficient ways of raising crops in times of blockade and near famine, to set up this institution where lectures would be given and research carried on. This was a new pattern for London and practical use was expected of it. Rumford had hoped that artisans would come to lectures on mechanics and that new inventions would be displayed there; the lecture theatre, like other theatres, had a separate entrance to the gallery so that the artisans would be segregated from the ladies and gentlemen occupying the best seats. In the event, manufacturers did not want to share their trade secrets but the lectures to the nobility and gentry became a great success during the winters and springs of the London season, while in the laboratory some of the most important experiments of the century were to be performed.
The professor of chemistry was Thomas Garnett, a well-known analyst of mineral waters who disliked London, but he soon died. The managers of the Royal Institution resolved on 28 June 1801 that Davy should in November give a course of lectures on the chemistry of tanning. He spent the summer learning about it, notably with Thomas Poole of Nether Stowey, a lifelong friend, whose tannery embodied the current best practices. Tanning was a disagreeable business which involved much capital because the hides underwent prolonged immersions in various solutions; however, leather, flexible and strong, was a crucial material, and the oak bark and galls necessary to tan it seemed to be becoming scarce. Davy's lectures were supplemented by a major paper, published by the Royal Society in 1803 and largely responsible for his being elected a fellow later that year and awarded its highest honour, the Copley medal, in 1805.
Davy's main conclusion was that the workmen in the best tanneries had arrived at a degree of perfection which could not be very far extended by chemical theory: he provided in essence a rationale for the best practice, which had been arrived at by lengthy trial and error. Poole found tannin in port wine, and Davy in tea, and more promisingly, in catechu from India. Sir Joseph Banks, president of the Royal Society from 17781820, who became in effect Davy's patron, supplied samples of the latter, used as an astringent when chewing betel nut, and Davy had a pair of shoes made, one tanned with oak bark and the other with catechu. Here was a promise of replacing oak bark with a cheaper alternative.
Davy gave a general account of the chemistry of tanning which was not significantly improved upon in the next fifty years, and again he moved on. This time it was to agriculture, at the suggestion of his employers and the board of agricultureagain two overlapping groups. He gave a series of lectures year after year, which promised increased production, bringing relief from the wartime food shortages and the pressures of an expanding population (Thomas Malthus's Essay on Population
had appeared in 1798). If all farms could be brought up to the standard of the best, there would be no problem. Davy urged good practice, beginning with soil analysis: he undertook to do analyses himself, and became a close friend of Thomas Andrew Knight, an eminent plant physiologist and horticulturist on whose estate he went fishing. Davy also supervised a series of experiments at Woburn, under the patronage of the duke of Bedford, on grasses, and on one occasion at the festivities associated with the annual sheep shearing at Woburn, Davy was toasted.
Davy's suggestions were conservative, often providing a scientific basis for practices that had been found empirically to work. Thus he recommended using manure fresh rather than rotted, because it would then still contain much ammonia, and illustrated this with what must have been a rather smelly experiment, in which the fumes rising from dung were conducted beneath a piece of turf, which grew splendidly. He also suggested insecticides, one of which seems to have killed off Lord Egremont's turnip crop, but which generally appear to have been helpful. The lectures were eventually published, first in a handsome quarto and then in octavo, in 1813, and remained a standard work for a generation. This was essentially science as nothing more than the refinement of common sense making use of facts already known to acquire new facts (Collected Works
, 9.355), as Davy put it in a phrase later echoed by T. H. Huxley.
It turned out that Davy was a brilliant lecturer and in January 1802 he gave an introductory lecture to a course on chemistry, which created a sensation and led to his being appointed the institution's professor of chemistry in May of that year. He presented a dazzling picture of scientific and technical progress, and this vision of the power of applied science remained with him and his successors at the institution. He became much sought after as a dinner party guest. He spent the time between ten or eleven o'clock in the mornings and three or four in the afternoon in the laboratory, and then dressed for dinnerthere were stories of his rushing from the laboratory and putting a clean shirt on top of his dirty onebut on evenings before lectures he dined at home on fish and rehearsed with his assistants. There are messy manuscripts of the lectures, difficult to read; he must have delivered them from memory, maintaining eye-contact with the audiencehis eyes were said to be very bright and striking. He was about 5 ft 7 in. in height, but seemed shorter; he soon lost any traces of Cornish accent, and while some found his voice affected, most seem to have delighted in hearing him. The traffic bringing hearers to his lectures was so heavy that Albemarle Street had to be one-way on those nights. He had perfected the art of high-level popularization, and made science attractive and interesting to both men and women.
In 1804 Gregory Watt died, and Davy was desolate, writing about his belief in the individual immortality of the better part of man. In the same year, Coleridge, unhappy in his marriage and addicted to opium, set off for Malta in a desperate bid to regain his health. He was cheered on his way by a splendid letter from Davy, who on his return arranged for him to lecture at the Royal Institution. In 1808 Beddoes died, after writing a melancholy letter to Davy deploring his own lack of definite scientific achievement. By then Davy had moved far beyond his earlier sphere. In 1807 he was elected one of the two secretaries of the Royal Society, with the responsibility of editing its journal, and he had made new friends among the medical and scientific community in London, where he was one of the first to make a living by the practice, or profession, of science. On holidays he studied geology and fished energetically; autumns were his best time for undisturbed research, and in 1806 his work took a new turn, which brought international fame.
Reconstructing chemistry: potassium and chlorine
Davy believed that electricity was a force or power, not a substance, and that it would simply decompose substances like water. But the experiments of others revealed acids and alkalis that were apparently generated electrically, so perhaps there were compounds of electricitygalvanates. In October 1806, using apparatus of gold, silver, and agate, and excluding air, Davy verified his conjecture in an excellent example of a goal-directed rather than open-ended experiment: pure water, decomposed by electrical action, yielded nothing but hydrogen and oxygen, in the right proportions. He concluded that electricity and chemical affinity were manifestations of one power. This insight (though not quantitative) seemed appropriate to the would-be Newton of chemistry, and it won him a prize from the Paris Académie des Sciences.
On 19 October 1807 Davy used electricity to decompose caustic potash, in a capital experiment after which he danced about the laboratory in ecstatic delight. The application of electric current to an aqueous solution of the alkali resulted in the water's being decomposed into hydrogen and oxygen. The resulting residue of solid potash did not conduct electricity and so Davy melted it. When he did so, globules of the substance formed at the negative pole and, bursting into flames, threw off bright coruscations. He managed to collect some, and found that they floated on water, catching fire as they decomposed it; he compared his potagen to the alkahest sought by alchemists, but after consultation with other chemists decided that this anomalous substance was in fact a metal, and named it potasium, later potassium. Soon he isolated sodium too, and then, using a mercury cathode, calcium and other alkaline earth metals.
Davy's papers describing these researches were chosen as the Bakerian lectures of the Royal Society and marked him as one of the greatest men of science of the day. British science was provincial compared to that in Paris, but now patriots and upholders of freedom could rejoice that a Briton had given chemistry a new direction, making it seem the fundamental science. Davy meanwhile had been consulted about the ventilation of Newgate prison, had visited it, and had then gone down with gaol fever in the hour of his triumph. Medical bulletins were posted at the Royal Institution, but for the first few months of 1808 he was unable to do research or to lecture.
Davy had been a founder of the Geological Society of London, but had promptly resigned under pressure from Banks, who was determined that men of science must hang together in these difficult years in one learned empire and resist anything which looked like fragmentation. Davy was, however, prominent in the Animal Chemistry Club, a subset of the Royal Society where physiology was discussed amid worries about French materialism. He now turned his attention to acidity. It was known that the bad-eggs acid, hydrogen sulphide, contained no oxygen; in research with his friend J. G. Children, Davy proved that the even worse-smelling hydrogen telluride contained none either. Eventually on 12 July 1810 he announced his conclusion that the strong acid from sea salt also contained none: that there was no material basis for acidity. In November of that year, he declared that the green gas contained in this acid was an element, and named it chlorine. For him and his contemporaries, muriatic acid and sulphuric acid had no element in commonLavoisier had been wrong both about heat and acidity. In triumphant lectures Davy emphasized how the French had been dogmatic about what was in fact the baseless fabric of a vision. He stood at the apex of the scientific world.
Marriage, France, and the safety lamp
Davy's income at this point was about £1000 a year, making him a not especially eligible bachelor, but on 2 March 1812 Jane Apreece, née
Kerr (17801855) [see
], a wealthy widow whom he had been pursuing, accepted his proposal of marriage. She had held a salon in Edinburgh and was sophisticated, well-connected, and intellectual. On 8 April 1812 Davy was knighted by the prince regent, and on the 11th he and Jane were married by the bishop of Carlisle at Jane's mother's house in Portland Place. They spent their honeymoon in Scotland, staying with eminent people; Davy took his little apparatus with him, and conducted some researches on gunpowder. He gave up his courses of lectures, and wrote up his Elements of Chemical Philosophy
the same year. This, dedicated to Jane, dealt with his own work, and was meant to be the first of a multi-volume set, but it did not sell well, for it was not a satisfactory textbook and his researches were accessible in the Royal Society's Philosophical Transactions
Investigating the first high explosive, nitrogen trichloride (which cost its French discoverer an eye and a finger), Davy was disabled in an explosion. As amanuensis he employed Michael Faraday, who had just finished his time as a bookbinder's apprentice. Faraday had read some of the books, and had been given a ticket for what turned out to be Davy's last lecture course, on chlorine. He aspired to a career in science and made a fair copy of his notes, which he presented to Davy. Davy advised him to stick with his trade and smiled at his notion of the nobility of natural philosophers, but nevertheless, on 1 March 1813, on Davy's recommendation, Faraday was given a job at the institution.
On 13 October 1813, the Davys set out for France; passports then came from the country visited, and he had been given one in order to collect his prize. With them, as assistant and sometimes valet, went Faraday. In the enemy capital, Paris, Davy behaved like a Coriolanus fighting alone in science for his country. He refused to be impressed by a tour of the Louvre, which was full of Napoleon's loot, stalked out of an anti-British play, and competed with the leading French chemist, J. L. Gay-Lussac, to elucidate the nature of a curious new substance: recognizing its analogy with chlorine, he called it iodine.
From Paris they went to Italy, which was less of an intellectual hothouse but more congenial, where Davy investigated petrifying springs and carried out some of the first analyses of pigments used in ancient paintings. In Naples, where they observed Vesuvius in eruption, they were planning to go on to Constantinople when they heard of Napoleon's return from Elba; they left on 21 March 1815 and arrived home via the Rhineland on 23 April. On holiday in Scotland in August, Davy received a letter from the Revd Robert Gray of Bishopwearmouth asking him, as Britain's leading man of science, to do something about explosions in coalmines. On 14 August, Davy stopped in Newcastle and met John Buddle, the leading colliery manager or viewer, and another clergyman, the Revd John Hodgson of Jarrow.
Davy went straight to London, declining an invitation to visit Banks, and Buddle sent him samples of the gas, firedamp, which issued from the coal and caused the explosions. It was often supposed to be hydrogen, but Davy, working with Faraday as his assistant, proved that it was methane. He found that a mixture of air and methane will explode only at a high temperature, and by 30 October had devised a lamp where the gases entered and left through narrow tubes to cool them down. He went on to enclose the flame in a cylinder of wire gauze in the definitive form of the Davy lamp, which would explode only if white-hot, and which also functioned as a detector of firedamp. Banks wrote Davy a magnificent letter declaring that his work would place the Royal Society higher in popular opinion than all the abstruse discoveries beyond the understanding of ordinary people.
A device developed in the laboratory worked down the minethis was one of the very first examples of technology as applied science. George Stephenson had developed a similar lamp at the same time, in the older trial-and-error fashion, and there were priority disputes. Davy refused to patent his lamp, and so the matter was never tested in court; understanding the principle, he indignantly rejected Stephenson's claims to have invented a safe lamp, which were pressed sometimes scurrilously by his partisans. Davy was awarded the Royal Society's Rumford medal, a set of plate presented at a public meeting by his old friend Lambton, and a baronetcy: though this was the highest honour yet accorded to a man of science it was an empty honour for a childless man, and was in contrast with the honours showered upon military men for destroying their fellow creatures.
In the course of his work, Davy found that, in the presence of a coil of platinum wire, firedamp and air will combine without explosion, the first example of what came to be known as heterogeneous catalysis. The Davys went for another continental tour, during which they received recognition for the miner's lamp (and tried to unroll papyri from Herculaneum). Then, in 1820, Banks died; he had been president of the Royal Society since a few days before Davy was born, and as the gentleman with the lamp, Davy was the unstoppable candidate to succeed him. The shy W. H. Wollaston, Banks's preferred successor, declined a contest, and on 30 November 1820 Davy was elected to what was then a position of lonely eminence in the world of British science.
President of the Royal Society
In the event, Davy's reputation was tarnished by his taking this responsibility: had he died in 1819 it would have been glittering. The society was teetering between remaining a gentlemen's club and becoming an academy of sciences. Davy favoured judicious modernizing and was tolerant of specialisms, and during his presidency the council of the society came to include a majority of men with one or more scientific publications. He made publication an important factor in election, but, lacking the social status of Banks, he was unable to force his will upon the fellows, and found himself between hostile camps, pleasing nobody. Social mobility was recognized then and now as the key to his life, but it had its limits. His patronage secured Children a post at the British Museum, though this weakened confidence in that institution. With Stamford Raffles he set up the London Zoo, as a kind of response to the Museum of Natural History in Paris. He was one of the founders of the Athenaeum, as a real club for intellectual gentlemen.
Davy's relationship with Faraday was a casualty of his elevation. He had in 1816 tactfully propelled Faraday into publication, and eased him through what was in effect an apprenticeship; Faraday's status changed from laboratory assistant, to research student, to junior colleague, and he devotedly preserved and bound Davy's scribbled experimental notes and drafts. There was then no clear point to mark academic coming-of-age, but Faraday by 1821 no longer needed a fatherly supervisor to make helpful suggestions about his papers, for example on the liquefaction of gases; he began independent research, and took up work in electromagnetism which looked a bit like trespassing on Wollaston's territory. Faraday was not good at flattering distinguished elders, and he felt that Davy (whose relationship with Wollaston was respectful but not very close) failed to support him. In 1823, without consulting Davy, he allowed his name to go forward for fellowship of the Royal Society; Davy felt indignant and offended, told him to withdraw, and sulked when he refused. Faraday was elected, and he and Davy were now distanced in a kind of family row which they never really resolved. Two masters of scientific rhetoric found themselves inarticulate, and it was not until after Davy's death that Faraday was able to break fully from his shadow and embark on his own fundamental electrical researches.
In 1823 Davy took upon himself research into the corrosion of the copper bottoms of warships. He showed that this ceased if protectors of a more reactive metal were attached, and these were tried, with Davy going on one of the experimental voyages, to Scandinavia. The protector gave a negative charge to the copper but unfortunately this proved attractive to marine organisms, and protected ships sailed badly. In this case scaling up from the laboratory did not work in the more complex conditions of the outside world and Davy was much mortified.
Last years: contemplating death's shadow
At the anniversary meeting of the Royal Society on 30 November 1826 Davy was re-elected unopposed, but his speech was made with such effort that drops of sweat flowed down his countenance and he was unable to attend the dinner which followed. In December he had a stroke; he was forty-eight. His adoring younger brother, , who had trained as a doctor at his expense in Edinburgh and was serving with the army, hurried to his bedside, and on 22 January 1827 they set out for Italy. Rides in the woods around Ravenna and a low diet restored Davy's health somewhat but he brooded upon the transience of things. On 30 June he wrote from Salzburg to his wife, and also to his friend Davies Gilbert, that he would resign his presidency at the next anniversary. His favoured candidate was Robert Peel, whose wealth, influence, and lack of any specific scientific reputation would be very valuable: through Peel, Davy had earlier induced the king to found royal medals for science. He invited Jane to join him for the winter in Italy, but when this proved impossible he resolved unhappily in September to return to England. His love of natural history had not deserted him, and he decided to write a series of dialogues on the subject, entitled Salmonia, or, Days of Fly-Fishing
By the time the book appeared Davy was back on the continent, never to return home. He had set out on 29 March 1828 accompanied by James Tobin, a German-speaking medical studentthe son of an old friend of Bristol dayswhose long trip in the company of an invalid curmudgeon does not seem to have been much fun. Tobin read endlessly to him, and he fished and shot in solitude. In Slovenia he was consoled by Josephine Detela, whose nickname was Papina, the daughter of an innkeeper in Ljubljana. He loved the Julian alps, fishing and seeking the sources of rivers; a house he took at Podkoren on the Wurzen pass, among beech woods, bears a plaque in his memory. He was delighted about Roman Catholic emancipation, being sympathetic to that church because of his experiences in Italy and Austria, and earlier in his beloved Ireland where he had lectured, and where Trinity College, Dublin, gave him a doctorate in 1811.
was a success, and had an enthusiastic review from his friend Walter Scott. He resolved to extend it with general reflections upon life and science. Coming to terms with his prematurely worn-out body, he also began dictating to Tobin a series of dialogues on life, immortality, the pursuit of science, and the nature of time. These were just completed (though had he lived longer he might have added more) on his deathbed, and published posthumously in 1830 as Consolations in Travel, or, The Last Days of a Philosopher
. The book represents his legacy, and although all the characters clearly represent the author (with some features of Wollaston and other friends), it is a good read and takes us to some extent into his mind, and into the science of his time. We see again the lecturer who had disclosed nature's coyest secrets to those audiences at the Royal Institution, and the participant in the Animal Chemistry Club. Georges Cuvier, in his eulogy of Davy for the Paris Académie des Sciences, described the book as the work of a dying Plato.
Davy wintered in Rome, and there spent his fiftieth birthday hunting in the Campagna, but on 20 February 1829 he had another stroke. He thanked God he had been able to finish all his philosophical labours, and was like to die. His wife and brother were summoned, but he rallied. One day Tobin read Shakespeare to him for nine hours. The party set off for England, but at Geneva, after Tobin had read Humphry Clinker
until 10 p.m. Davy died peacefully in the early hours of 29 May 1829. Fearful of being buried alive, and squeamish about post-mortems, he had requested that interment be delayed but the laws of Geneva did not permit it. He was given a civic funeral the following Monday, 1 June 1829, and buried at the cemetery of Plain-Palais. His wife had a memorial tablet put up in Westminster Abbey, for which she was charged £142.
Despite the success of his last works, and his brother's efforts, Davy's reputation was soon eclipsed by that of Faraday. Historians of science concentrating upon positive contributions found little to remark after 1815, but Davy can be seen as one of the first professional men of science, which brought him a high if not always comfortable social position, and tremendous fame. His dialogues, written when he was given time for reflection, moving from science to wisdom, help the reader to enter a world that existed before there were two cultures, where the discoverer was becoming a sage.