Sir Humphry Davy, 1st Baronet (17 December 1778 – 29 May 1829) was a Cornish chemist and inventor. He is best remembered today for his discoveries of several alkali and alkaline earth metals, as well as contributions to the discoveries of the elemental nature of chlorine and iodine.
Berzelius called Davy’s 1806 Bakerian Lecture On Some Chemical Agencies of Electricity “one of the best memoirs which has ever enriched the theory of chemistry.” He was a 1st Baronet, President of the Royal Society (PRS), Member of the Royal Irish Academy (MRIA), and Fellow of the Geological Society (FGS).
Davy was born in Penzance in Cornwall on 17 December 1778. His family moved to Varfell, near Ludgvan, when he was nine, and in term-time Davy boarded with John Tonkin, his mother’s godfather.
After the Penzance school he attended Truro Grammar School in 1793 to finish his education under the Rev Dr Cardew, who, in a letter to Davies Gilbert, said dryly: “I could not discern the faculties by which he was afterwards so much distinguished.” Davy said: “I consider it fortunate I was left much to myself as a child, and put upon no particular plan of study… What I am I made myself.”
After Davy’s father died in 1794, Tonkin apprenticed him to John Bingham Borlase, a surgeon with a practice in Penzance. Davy’s indenture is dated 10 February 1795. In the apothecary’s dispensary, Davy became a chemist, and a garret in Tonkin’s house was where he conducted his earliest chemical experiments. Davy’s friends said: “This boy Humphry is incorrigible. He will blow us all.” His eldest sister complained of the ravages made on her dresses by corrosive substances.
John Ayrton Paris remarked that poetry written by the young Davy “bear the stamp of lofty genius”. Davy’s first preserved poem entitled The Sons of Genius is dated 1795 and marked by the usual immaturity of youth. Other poems written in the following years, especially On the Mount’s Bay and St Michael’s Mount, are descriptive verses, showing sensibility but no true poetic imagination.
Three of Davy’s paintings from around 1796 have been donated to the Penlee House museum at Penzance. One is of the view from above Gulval showing the church, Mount’s Bay and the Mount, while the other two depict Loch Lomond in Scotland.
While writing verses at the age of 17 in honour of his first love, he was eagerly discussing the question of the materiality of heat with his Quaker friend and mentor Robert Dunkin. Dunkin remarked: ‘I tell thee what, Humphry, thou art the most quibbling hand at a dispute I ever met with in my life.’
One winter day he took Davy to the Larigan River, to show him that rubbing two plates of ice together developed sufficient energy by motion, to melt them, and that after the motion was suspended, the pieces were united by regelation.
It was a crude form of analogous experiment exhibited by Davy in the lecture-room of the Royal Institution that elicited considerable attention. As professor at the Royal Institution, Davy repeated many of the ingenious experiments he learned from his friend and mentor, Robert Dunkin.
Davies Giddy met Davy in Penzance carelessly swinging on the half-gate of Dr Borlase’s house, and interested by his talk invited him to his house at Tredrea and offered him the use of his library. This led to an introduction to Dr Edwards, who lived at Hayle Copper House. Edwards was a lecturer in chemistry in the school of St. Bartholomew’s Hospital.
He permitted Davy to use his laboratory and possibly directed his attention to the floodgates of the port of Hayle, which were rapidly decaying as a result of the contact between copper and iron under the influence of seawater.
Galvanic corrosion was not understood at that time, but the phenomenon prepared Davy’s mind for subsequent experiments on ship’s copper sheathing. Gregory Watt, son of James Watt, visited Penzance for his health’s sake, and while lodging at the Davy’s house became a friend and gave him instructions in chemistry. Davy was acquainted with the Wedgwood family, who spent a winter at Penzance.
Thomas Beddoes and John Hailstone were engaged in a geological controversy on the rival merits of the Plutonian and Neptunist hypotheses. They travelled together to examine the Cornish coast accompanied by Davies Gilbert and made Davy’s acquaintance. Beddoes, who had established at Bristol a ‘Pneumatic Institution,’ needed an assistant to superintend the laboratory.
Gilbert recommended Davy, and in 1798 Gregory Watt showed Beddoes the Young man’s Researches on Heat and Light, which were subsequently published by him in the first volume of West-Country Contributions.
After prolonged negotiations, mainly by Gilbert, Mrs Davy and Borlase consented to Davy’s departure, but Tonkin wished him to remain in his native town as a surgeon, and altered his will when he found that Davy insisted on going to Dr Beddoes.
In 1802, Humphry Davy had what was then, the most powerful electrical battery in the world at the Royal Institution.
With it, Davy created the first incandescent light by passing a current through a thin strip of platinum, chosen because the metal had an extremely high melting point. It was neither sufficiently bright nor long lasting enough to be of practical use, but demonstrated the principle.
By 1806 he was able to demonstrate a much more powerful form of electric lighting to the Royal Society in London. It was an early form of arc light which produced its illumination from an electric arc created between two charcoal rods.
Davy was a pioneer in the field of electrolysis using the voltaic pile to split common compounds and thus prepare many new elements.
He went on to electrolyse molten salts and discovered several new metals, including sodium and potassium, highly reactive elements known as the alkali metals.
Davy discovered potassium in 1807, deriving it from caustic potash (KOH). Before the 19th century, no distinction had been made between potassium and sodium.
Potassium was the first metal that was isolated by electrolysis. Davy isolated sodium in the same year by passing an electric current through molten sodium hydroxide. Davy discovered calcium in 1808 by electrolyzing a mixture of lime and mercuric oxide.
Davy was trying to isolate calcium; when he heard that Berzelius and Pontin prepared calcium amalgam by electrolyzing lime in mercury, he tried it himself. He worked with electrolysis throughout his life and was first to isolate magnesium, boron, and barium.
Chlorine was discovered in 1774 by Swedish chemist Carl Wilhelm Scheele, who called it “dephlogisticated marine acid” (see phlogiston theory) and mistakenly thought it contained oxygen. Davy showed that the acid of Scheel’s substance, called at the time oxymuriatic acid, contained no oxygen. This discovery overturned Lavoisier’s definition of acids as compounds of oxygen. In 1810, chlorine was given its current name by Humphry Davy, who insisted that chlorine was in fact an element.
Davy revelled in his public status, as his lectures gathered many spectators. He became well known in 1799 due to his experiments with the physiological action of some gases, including laughing gas (nitrous oxide), with enthusiastic experimental subjects including his poet friends Robert Southey and Samuel Taylor Coleridge.
Davy later damaged his eyesight in a laboratory accident with nitrogen trichloride. Pierre Louis Dulong first prepared this compound in 1812, and lost two fingers and an eye in two separate explosions with it. Davy’s own accident induced him to hire Michael Faraday as a coworker.
In 1812, Davy was knighted, gave a farewell lecture to the Royal Institution, and married a wealthy widow, Jane Apreece. (While Davy was generally acknowledged as being faithful to his wife, their relationship was stormy, and in later years he travelled to continental Europe alone.) In October 1813, he and his wife, accompanied by Michael Faraday as his scientific assistant (and valet), travelled to France to collect a medal that Napoleon Bonaparte had awarded Davy for his electro-chemical work.
While in Paris, Davy was asked by Gay-Lussac to investigate a mysterious substance isolated by Bernard Courtois. Davy showed it to be an element, which is now called iodine.
The party left Paris in December 1813, travelling south to Italy. They sojourned in Florence, where, in a series of experiments conducted with Faraday’s assistance, Davy succeeded in using the sun’s rays to ignite diamond, proving it is composed of pure carbon.
Davy’s party continued to Rome, and also visited Naples and Mount Vesuvius. By June 1814, they were in Milan, where they met Alessandro Volta, and then continued north to Geneva. They returned to Italy via Munich and Innsbruck, and when their plans to travel to Greece and Istanbul were abandoned after Napoleon’s escape from Elba, they returned to England.
After his return to England in 1815, Davy experimented with lamps for use in coal mines. There had been many mining explosions caused by firedamp or methane often ignited by open flames of the lamps then used by miners.
In particular the Felling mine disaster in 1812 near Newcastle caused great loss of life, and action was needed to improve underground lighting and especially the lamps used by miners.
Davy conceived of using an iron gauze to enclose a lamp’s flame, and so prevent the methane burning inside the lamp from passing out to the general atmosphere.
Although the idea of the safety lamp had already been demonstrated by William Reid Clanny and by the then unknown (but later very famous) engineer George Stephenson, Davy’s use of wire gauze to prevent the spread of flame was used by many other inventors in their later designs.
George Stephenson’s lamp was very popular in the north-east coalfields, and used the same principle of preventing the flame reaching the general atmosphere, but by different means. Unfortunately, although the new design of gauze lamp initially did seem to offer protection, it gave much less light, and quickly deteriorated in the wet conditions of most pits.
Rusting of the gauze quickly made the lamp unsafe, and the number of deaths from firedamp explosions rose yet further.
There was some discussion as to whether Davy had discovered the principles behind his lamp without the help of the work of Smithson Tennant, but it was generally agreed that the work of both men had been independent. Davy refused to patent the lamp, and its invention led to his being awarded the Rumford medal in 1816.
In 1815 Davy suggested that acids were substances that contained replaceable hydrogen – hydrogen that could be partly or totally replaced by metals. When acids reacted with metals they formed salts. Bases were substances that reacted with acids to form salts and water. These definitions worked well for most of the nineteenth century.
In January 1819, Davy was awarded a baronetcy. Although Sir Francis Bacon (also later made a peer) and Sir Isaac Newton had already been knighted, this was, at the time, the first such honour ever conferred on a man of science in Britain. A year later he became President of the Royal Society.
Davy’s laboratory assistant, Michael Faraday, went on to enhance Davy’s work and would become the more famous and influential scientist. Davy is supposed to have even claimed Faraday as his greatest discovery. Davy later accused Faraday of plagiarism, however, causing Faraday (the first Fullerian Professor of Chemistry) to cease all research in electromagnetism until his mentor’s death.
Of a sanguine, somewhat irritable temperament, Davy displayed characteristic enthusiasm and energy in all his pursuits. As is shown by his verses and sometimes by his prose, his mind was highly imaginative; the poet Coleridge declared that if he “had not been the first chemist, he would have been the first poet of his age”, and Southey said that “he had all the elements of a poet; he only wanted the art.”
In spite of his ungainly exterior and peculiar manner, his happy gifts of exposition and illustration won him extraordinary popularity as a lecturer, his experiments were ingenious and rapidly performed, and Coleridge went to hear him “to increase his stock of metaphors.”
The dominating ambition of his life was to achieve fame, but though that sometimes betrayed him into petty jealousy, it did not leave him insensible to the claims on his knowledge of the “cause of humanity”, to use a phrase often employed by him in connection with his invention of the miners’ lamp. Of the smaller observances of etiquette he was careless, and his frankness of disposition sometimes exposed him to annoyances which he might have avoided by the exercise of ordinary tact.
According to one of Davy’s biographers, June Z. Fullmer, he was a deist.
He spent the last months of his life writing Consolations in Travel, an immensely popular, somewhat freeform compendium of poetry, thoughts on science and philosophy. Published posthumously, the work became a staple of both scientific and family libraries for several decades afterward.
Davy spent the winter in Rome, hunting in the Campagna on his fiftieth birthday. But on 20 February 1829 he had another stroke. After spending many months attempting to recuperate, Davy died in a hotel room in Geneva, Switzerland, on 29 May 1829.
He had wished to be buried where he died, but had also wanted the burial delayed in case he was only comatose. He refused to allow a post-mortem for similar reasons.
But the laws of Geneva did not allow any delay and he was given a public funeral on the following Monday, in the Plainpalais Cemetery, outside the city walls. Jane organised a memorial tablet for him, in Westminster Abbey shortly afterwards, at a cost of £142.