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 character of phosphorus, sulphur and carbon, though on this point he afterwards corrected himself. He also described the preparation of boron, for which at first he proposed the name boracium, on the impression that it was a metal. About this time a voluntary subscription among the members of the Royal Institution put him in possession of a new galvanic battery of 2000 double plates, with a surface equal to 128,000 sq. in., to replace the old one, which had become unserviceable. His fourth Bakerian lecture, in November 1809, gave further proofs of the elementary nature of potassium, and described the properties of telluretted hydrogen. Next year, in a paper read in July and in his fifth Bakerian lecture in November, he argued that oxymuriatic acid, contrary to his previous belief, was a simple body, and proposed for it the name “chlorine.”

Davy’s reputation was now at its zenith. As a lecturer he could command an audience of little less than 1000 in the theatre of the Royal Institution, and his fame had spread far outside London. In 1810, at the invitation of the Dublin Society, he gave a course of lectures on electro-chemical science, and in the following year he again lectured in Dublin, on chemistry and geology, receiving large fees at both visits. During his second visit Trinity College conferred upon him the honorary degree of LL.D., the only university distinction he ever received. On the 8th of April 1812 he was knighted by the prince regent; on the 9th he gave his farewell lecture as professor of chemistry at the Royal Institution; and on the 11th he was married to Mrs Apreece, daughter and heiress of Charles Kerr of Kelso, and a distant connexion of Sir Walter Scott. A few months after his marriage he published the first and only volume of his Elements of Chemical Philosophy, with a dedication to his wife, and was also re-elected professor of chemistry at the Royal Institution, though he would not pledge himself to deliver lectures, explaining that he wished to be free from the routine of lecturing in order to have more time for original work. Towards the end of the year he began to investigate chloride of nitrogen, which had just been discovered by P. L. Dulong, but was obliged to suspend his inquiries during the winter on account of injury to his eye caused by an explosion of that substance. In the spring of 1813 he was engaged on the chemistry of fluorine, and though he failed to isolate the element, he reached accurate conclusions regarding its nature and properties. In October he started with his wife for a continental tour, and with them, as “assistant in experiments and writing,” went Michael Faraday, who in the previous March had been engaged as assistant in the Royal Institution laboratory. Having obtained permission from the French emperor to travel in France, he went first to Paris, where during his two months’ stay every honour was accorded him, including election as a corresponding member of the first class of the Institute. He does not, however, seem to have reciprocated the courtesy of his French hosts, but gave offence by the brusqueness of his manner, though his supercilious bearing, according to his biographer, Dr Paris, was to be ascribed less to any conscious superiority than to an “ungraceful timidity which he could never conquer.” Nor was his action in regard to iodine calculated to conciliate. That substance, recently discovered in Paris, was attracting the attention of French chemists when he stepped in and, after a short examination with his portable chemical laboratory, detected its resemblance to chlorine and pronounced it an “undecompounded body.” Towards the end of December he left for Italy. At Genoa 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. Then he went to Rome and Naples and visited Vesuvius and Pompeii, called on Volta at Milan, spent the summer in Geneva, and returning to Rome occupied the winter with an inquiry into the composition of ancient colours.

A few months after his return, through Germany, to London in 1815, he was induced to take up the question of constructing a miner’s safety lamp. Experiments with samples of fire-damp sent from Newcastle soon taught him that “explosive mixtures of mine-damp will not pass through small apertures or tubes”; and in a paper read before the Royal Society on the 9th of November he showed that metallic tubes, being better conductors of heat, were superior to glass ones, and explained that the heat lost by contact with a large cooling surface brought the temperature of the first portions of gas exploded below that required for the firing of the other portions. Two further papers read in January 1816 explained the employment of wire gauze instead of narrow tubes, and later in the year the safety lamps were brought into use in the mines. 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 disinterestedness the Newcastle coal-owners in September 1817 presented him with a dinner-service of silver plate.

In 1818, when he was created a baronet, he was commissioned by the British government to examine the papyri of Herculaneum in the Neapolitan museum, and he did not arrive back in England till June 1820. In November of that year the Royal Society, of which he had become a fellow in 1803, and acted as secretary from 1807 to 1812, chose him as their president, but his personal qualities were not such as to make him very successful in that office, especially in comparison with the tact and firmness of his predecessor, Sir Joseph Banks. In 1821 he was busy with electrical experiments and in 1822 with investigations of the fluids contained in the cavities of crystals in rocks. In 1823, when Faraday liquefied chlorine, he read a paper which suggested the application of liquids formed by the condensation of gases as mechanical agents. In the same year 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, much to the inventor’s annoyance, especially as orders to remove the protectors already fitted were issued in June 1825, immediately after he had announced to the Royal Society the full success of his remedy.

In 1826 Davy’s health, which showed signs of failure in 1823, had so declined that he could with difficulty indulge in his favourite sports of fishing and shooting, and early in 1827, after a slight attack of paralysis, he was ordered abroad. After a short stay at Ravenna he removed to Salzburg, whence, his illness continuing, he sent in his resignation as president of the Royal Society. In the autumn he returned to England and spent his time in writing his Salmonia or Days of Flyfishing, an imitation of The Compleat Angler. In the spring of 1828 he again left England for Illyria, and in the winter fixed his residence at Rome, whence he sent to the Royal Society his “Remarks on the Electricity of the Torpedo,” written at Trieste in October. This, with the exception of a posthumous work, Consolations in Travel, or the Last Days of a Philosopher (1830), was the final production of his pen. On the 20th of February 1829 he suffered a second attack of paralysis which rendered his right side quite powerless, but under the care of his brother, Dr John Davy (1791–1868), he rallied sufficiently to be removed to Geneva, where he died on the 29th of May.

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 