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 papers the council of the Royal Society adjudged to him their Copley medal. He was elected secretary to that society on 22 Jan. 1807, on the death of Dr. Edward Whitaker Gray, and in January 1807 he became a member of the council. Davy's earliest experiments in galvanism had been made in 1800, when he mentions 'unhoped-for successes' in a letter to Gilbert. He was beginning fresh galvanic experiments in 1806, when the laboratory books of the Royal Institution show that in October he 'tried to decompose phosphorus by the galvanic fluid.' The discoveries of Volta at this time were exciting the attention of men of science. Davy worked zealously in developing the chemical action of the voltaic battery. He was now working with a battery of a hundred plates of six inches diameter. On 12 Nov. he informs his friend Mr. Pepys: 'I have decomposed and recomposed the fixed alkalies (potash and soda), and discovered their bases to be two new inflammable substitutes (potassium and sodium) very like metals, but one of them lighter than ether, and infinitely more combustible; so that there are two bodies decomposed, and two new elementary bodies found. Davy commenced those inquiries on the 16th and obtained his great result on 19 Oct. 1807. Shortly after this John George Children [q. v.] constructed the great battery with which his name is associated. This battery doubtless led to the collection, by the managers of the Royal Institution, of a fund for the construction of a yet more magnificent battery. It consisted of two hundred instruments connected together in regular order, each composed often double plates arranged in cells of porcelain, and containing in each plate thirty-two square inches, so that the whole number of double plates was two thousand, and the whole surface 128,000 square inches. With this powerful battery Davy repeated all his previous experiments, he instituted several with the hope of decomposing nitrogen, he most satisfactorily proved the actual character of oxymuriatic acid, he completely overthrew the theories of the Stahlian school, demonstrated in the most conclusive manner the existence of chlorine as a new elementary body, and proved its value as a bleaching agent. The announcement of a theory so adverse to the universal faith of chemists as that of chlorine being a simple substance which, combining with hydrogen, formed muriatic acid, was received with a storm of objections; but these were all refuted by vigorous methods of inquiry, and ultimately all the philosophers yielded their assent to Davy's views.

On 19 Nov. 1807 Davy explained all his experiments and discoveries in electricity before the Royal Society in the Bakerian lecture. His fame became European. Napoleon, then first consul, founded a prize of three thousand francs for the best experiments made on the galvanic fluid. Twelve months after the publication of Davy's lecture the Institute of France awarded him the Napoleon prize 'for his discoveries announced in the "Philosophical Transactions" for the year 1807.' In connection with galvanic phenomena Davy continued to achieve triumphs which greatly increased his fame, and considerably added to our stores of scientific truth.

At the close of 1807 Davy had a severe illness, occasioned probably by exposure to the unhealthy atmosphere of Newgate prison, the disinfecting of which he had undertaken. He was not able to resume his work until 19 April 1808, when he was again using his battery of 520 pair of plates. Through the spring and summer a series of beautiful experiments were made on ammonia and nitrogen. Davy tells Children, in a letter written at this time, that 'he hoped to show him nitrogen as a complete wreck, torn to pieces in different ways.' He was not successful, however, in decomposing nitrogen, but in his Bakerian lecture in December 1808, in which he elucidated the 'elementary matter of ammonia, the nature of phosphorus, sulphur, charcoal, and the diamond,' and in his fourth Bakerian lecture in 1809, he dealt particularly with 'the metallic bodies from the alkalies and earths, and on some combinations of hydrogen.' The Bakerian lecture for 1810 was devoted to the 'combinations of oxymuriatic gas and oxygen.' In that year the Dublin Society raised by subscription the sum of four hundred guineas, which they offered to Davy if he would deliver some lectures respecting the recent discoveries made by him in electro-chemical science. The 'Farming Society of Ireland,' being desirous of availing themselves of this opportunity, applied to Davy for six lectures on the application of chemistry to agriculture. Davy received 750l., and a large surplus went to defray expenses. In the following year Davy delivered two distinct courses in Dublin, one on the 'Elements of Chemical Philosophy,' and the other on 'Geology,' the proceeds from these lectures being 1,101l. 2s. Before Davy quitted Dublin the provost and fellows of Trinity College conferred upon him the honorary degree of LL.D. In the month of August Davy's opinion was requested by a committee as to the most satisfactory method of ventilating the House of Lords. Davy's recommendation was adopted, but it did not prove successful. On 8 April 1812 he was