DAVY, SIR HUMPHRY, BART. (1778-1829), English chemist, was born on Dec. 17, 1778, at Penzance, Cornwall. In his school days at the grammar schools of Penzance and Truro he showed few signs of a taste for scientific pursuits. During his apprenticeship to a surgeon-apothecary at Penzance he studied metaphysics, ethics and mathematics. He turned to chemistry at the end of 1797, and, after reading Nicholson's and Lavoisier's treatises he began a series of chemical experiments with any apparatus and materials he could obtain. About this time he made the acquaintance of Davies Giddy, afterwards Gilbert (1767 1839), who was president of the Royal Society (1827-31). Giddy recommended him to Dr. Thomas Beddoes, who was in 1798 establishing his Medical Pneumatic Institution at Bristol for investigating the medicinal properties of various gases. Here Davy, released from his indentures, was installed as superin tendent towards the end of 1798. Early next year two papers by him were published by Beddoes; these contained the results of Davy's crude experiments and theories hastily formed on in sufficient evidence.
One of his first discoveries at the Pneumatic Institution on April 9, was that pure nitrous oxide is perfectly respirable, and he narrates that on the next day he became "absolutely intoxi cated" through breathing 16 quarts of it for "near seven minutes." This discovery brought both him and the Pneumatic Institution into prominence, and Count Rumford, requiring a lecturer on chemistry for the recently established Royal Institution in Lon don, engaged him in 18oI as assistant lecturer in chemistry and director of the laboratory. He was almost at once appointed lec turer, and his promotion to be professor followed on May 31, 1802. One of his first tasks was the delivery of a course of lec tures on the chemical principles of tanning. The main facts he discovered from his experiments in this connection were described before the Royal Society in 1802-3. In 1802 the board of agri culture requested him to direct his attention to agricultural sub jects; and in 1803, with the acquiescence of the Royal Institution, he gave his first course of lectures on agricultural chemistry and continued them for ten successive years, ultimately publishing their substance as Elements of Agricultural Chemistry in 1813. Although Davy had taken up the subject by order, this book remained for nearly 5o years the standard work on the subject.
But his chief interest at the Royal Institution was with electro chemistry. His early work on this subject is summed up in his first Bakerian lecture "On some Chemical Agencies of Electricity." This paper gained him from the French Institute the medal offered by Napoleon for the best experiment made each year on "galvan ism." The discovery of potassium and sodium, and their prepara tion by an electrolytic method effected in Oct. 1807 was of great importance. According to his cousin, Edmund Davy, then his laboratory assistant, he was so delighted with this achievement that he danced about the room in ecstasy.
Four days after reading his second Bakerian lecture his health broke down, and he was unable to resume work until March i8o8. He continued to research on the alkalis and earths and his results were communicated in successive Bakerian lectures (1807-10) . Another important discovery due to Davy was that oxymuriatic acid was a simple substance ; he proposed the name "chlorine" for it. He succeeded in preparing boron, for which at first he proposed the name boracium, under the impression that it was a metal. Davy also discovered hydrogen telluride, hydrogen phosphide and a number of other compounds. On April 9, 1812, he gave his fare well lecture as professor of chemistry at the Royal Institution, though he continued his connection as an honorary professor. In that month he was knighted, and married to Mrs. Apreece, daughter and heiress of Charles Kerr of Kelso. A few months after his marriage he published the first and only volume of his Elements of Chemical Philosophy.
In Oct. 1813 he started with his wife for a continental tour, and with them, as "assistant in experiments and writing," went Michael Faraday, his assistant in the Royal Institution laboratory. In spite of the fact that England and France were at war Davy was welcomed in Paris, where he was made a corresponding mem ber of the first class of the Institute. From Paris he went to Genoa where he investigated the electricity of the torpedo-fish, and at Florence, by the aid of the great burning-glass in the Accademia del Cimento, he effected the combustion of the diamond in oxygen and decided that, beyond containing a little hydrogen, it consisted of pure carbon.
A few months after his return, through Germany, to London in 1815, he considered the construction of a miner's safety lamp. His lamps were brought into use in the mines in 1816. A large collection of the different models made by Davy in the course of his inquiries is in the possession of the Royal Institution. He took out no patent for his invention, and in recognition of his dis interestedness the Newcastle coal-owners in Sept. 1817 presented him with a dinner-service of silver plate. Davy's will directed that this service should pass to his brother, Dr. John Davy, on whose decease, if he had no heirs who could make use of it, it was to be melted and sold, the proceeds going to the Royal Society "to found a medal to be given annually for the most important discovery in chemistry anywhere made in Europe or Anglo America." The silver produced f 736, and the interest on that sum is expended on the Davy medal, which was awarded for the first time in 1877, to Bunsen and Kirchhoff for their discovery of spec trum analysis.
In 1818 he received a baronetcy for this signal service to indus try. In that year also he was commissioned by the British govern ment to examine the papyri of Herculaneum in the Neapolitan museum. He had been secretary of the Royal Society from 1807 to 1812, and on his return from Italy in 182o became presi dent, but his personal qualities did not make for success in that office, especially in comparison with the tact and firmness of his predecessor, Sir Joseph Banks. He directed his attention to various subjects, chiefly electromagnetism, but his researches were less successful than his earlier experiments. In 1823 the admiralty consulted the Royal Society as to a means of preserving the copper sheathing of ships from corrosion and keeping it smooth, and he suggested that the copper would be preserved if it were rendered negatively electrical, as would be done by fixing "protectors" of zinc to the sheeting. This method was tried on several ships, but it was found that the bottoms became extremely foul from accumulations of seaweed and shellfish. For this reason the admiralty decided against the plan. In 1826 Davy's health, which showed signs of failure in 1823, made rest necessary. The following years were spent chiefly abroad, and he died at Geneva on May 29, 1829. On this journey he wrote his Consolations in Travel (1830).
Of a sanguine, somewhat irritable temperament, Davy dis played characteristic enthusiasm and energy in all his pursuits. As is shown by his verses (all his life he found solace in writing verse) and sometimes by his prose, his mind was highly imagi native ; 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 in genious and rapidly performed, and Coleridge went to hear him "to increase his stock of metaphors." Though his ambition some times betrayed him into petty jealousy, it did not leave him in sensible to the claims on his knowledge of the "cause of humanity," to use a phrase often employed by him in connection with his in vention of the miners' lamp.