DAVOOT 



DAVY 



701 



u. \.-rthelens, did not forfeit his esteem. In the 

 KU-M in campaign of 181'2 lit- gathered fresh laurels 

 on the fields of Moliiluv and Vitebsk ('JTth .lul.vi. 

 Alter tin- retreat from MOM-OW, Davortt Itecame 

 "ovcnior ^. -in Tal of the Hanse towns, and at Ham- 

 burg, though hated for his cruelty, resolutely 

 maintained him-elt" till the restoration of the 

 Bourbons. On the return of Bonaparte from 

 Kllia, Davoflt was appointed war-minister, and as 

 such showed a remarkable genius for tlie rapid 

 organisation of troop* and supplies. After the 

 battle of Waterloo, he received the command of 

 tin 1 remnant of tlie French army under the walls of 

 Paris. He would have continui'd the contest had 

 In- not l>i'cn ordered ly tin- Provisional Government 

 in the capital to conclude a military convention 

 with the Allies. In 1819 he was made a peer of 

 France. His death took place June 1, 1823. 

 Firmness of character and dauntless courage were 

 Davoftt's leading characteristics ; but his military 

 severities often went the length of harshness, and 

 even cruelty, while his rapacity had in it something 

 akin to barbarism. See his Correspondance (4 vols. 

 IMS.")), and his Life by Chenier (1886), by his 

 daughter, the Marquise Blocqueville (3 vols. 1879- 

 80), and by Montcgut ( 1882). 



Davy, SIR HUMPHRY, one of the greatest 

 chemists, was born 17th December 1778, at Pen- 

 zance, Cornwall, where his father was a carver 

 in wood. At the school at Penzance, and after- 

 wards at Truro, he developed a taste for story- 

 telling, poetry, and angling, and for experimental 

 science, in which he was aided by Dunkin, a 

 saddler. In 1795 he became apprentice to a 

 surgeon and apothecary in Pen/ance, wrote verses, 

 and indulged in chemical experiments. He at the 



books in juxtaposition with stanzas of poetry and 

 fragments of romance.' The study of natural 

 philosophy brought him near to that department 

 which was to be his own ; but it was not till he 

 had reached his nineteenth year that he entered 

 seriously upon the study of chemistry. He was 

 then introduced to the notice of Dr Beddoes (q.v.), 

 who in 1798 established a Pneumatic Institute at 

 Clifton, and took him as his assistant. Here he 

 made the acquaintance of the Earl of Durham, 

 of ( 'oleridge, and Southey, and carried on a course 

 of experiments on the respiration of different gases, 

 in which he had more than once nearly sacrificed 

 his life. He thus discovered the singular exhilar- 

 ating effect of nitrous oxide when breathed. The 

 account which he published in his Researches 

 Chemical a ml I'hiliian(>liinil (1799), although after- 

 wards regretted, established his reputation, and 

 led to his appointment, at the age or twenty-two, 

 as lecturer to the Royal Institution of London. 

 He delivered his first lecture in 1801 ; and his 

 eloquence, and the novelty and variety of hi-^ ex- 

 periments, soon attracted crowded and brilliant 

 audiences. In 1803 he began researches connected 

 with agriculture, on which he delivered a course 

 of epoch-making lectures, which were published 

 under the title of Elements of Atjririiltnnil 

 Chemistry (1813). The discoveries, however, on 

 whidi Davy's fame as a chemist chiefly rests, 

 took their origin in the views which he de- 

 veloped in 1806, in his Bakerian lecture, On Some 

 Chemical Agencies of Electricity. This essay was 

 universally regarded as one of the most valuable 

 contributions ever made to chemical science, and 

 obtained the prize of the French Institute. Fol- 

 lowing out his principle, he was led to the grand 

 discovery that the alkalies and earths are com- 

 pound substances formed by oxygen united with 

 metallic bases. It was potash that he first suc- 



ceeded in decomposing, on the 19th Octolier 1807. 

 When he first haw tlie globules of the m-\\ metal, 

 jititiiimium, his delight is said to have lieen no 

 ecstatic that it required -.HIM- time for him to com- 

 pose himself to continue the ex|>eriment. He next 



ali 



soda and the alkaline earths, liaryta, 

 strontia, lime, and magnesia; and discovered the 

 new metals, sodium, barium, Ktrniitiiuii, <-nlrium t 

 ami magnesium. With regard to the earths projiur, 

 In- succeeded in proving that they consist of metals 

 united to oxygen. It was reserved for WoliN-r and 

 others to exhibit the metals by themselves. He 

 lectured in Dublin in 1808-9, ami received the 

 honorary degree of LL.D. from Trinity College. 



On 8th April 1812 Davy was knighted ; he 

 married Mrs Apreece, a lady of considerable 

 wealth, daughter and heiress of Charles Kerr of 

 Kelso, and resigned the chemical chair of the 

 Koyal Institution, April 1813. In order to mark 

 the high sense of his merits, he was elected honorary 

 professor of Chemistry. He discovered the talents 

 of Faraday (q.v.), for whom he secured the ap|M>int- 

 ment as assistant in the laWatory of the Koyal In- 

 stitution. That he might investigate his new theory 

 of volcanic action, he received permission from the 

 French government though the two countries were 

 then at war to visit the Continent, and was re- 

 ceived with the greatest distinction by the scientific 

 men of France. He was accompanied by Faraday. 

 On returning to England in 1815, he entered on tlie 

 investigation of the nature of fire-damp, which is 

 the cause of explosions in coal-mines. This resulted 

 in the invention of the Safety-lamp (q.v.). A 

 public subscription of about 1500 was collected as 

 a testimonial by those interested in 1817, and he was 

 entertained to dinner, and presented with a service 

 of plate. He was created a baronet, 20th Octolier 

 1818. On the death of Sir Joseph Banks in 1820, 

 Sir Humphry Davy was elected President of the 

 Koyal Society. In 1820-23 his researches on electro- 

 magnetism were communicated to the Society. He 

 invented an ingenious plan for preventing the cor- 

 rosion of the copper-sheathing of ships by altering 

 the electric condition of the copper by means of 

 bands of zinc ; but the bottoms of the* vessels lie- 

 came so foul from the adhesion of weeds and shells 

 that the plan had to be abandoned. 



Early in 1825 Sir Humphry Daw had begun to 

 complain of the loss of strength, and in 1826 he had 

 an apoplectic attack. He made two journeys to 

 the Continent for the recovery of his health, and 

 died at Geneva on the 29th May 1829, at the early 

 age of fifty-one. The Genevan government evinced 

 their respect by a public funeral. He was a memba 

 of almost all tne scientific institutions in the world. 

 Cuvier, in his tfloge, says : ' Davy, not yet fifty- 

 two years of age, occupied, in the opinion of all 

 that could judge of such labours, the first rank 

 among the chemists of this or of any other age.' 

 Another critic has said : ' He was not only one of 

 the greatest, but one of the most benevolent and 

 amiable of men.' His widow placet! a tablet to his 

 memory in Westminster Abbey, and a statue was 

 erected to him in Penzance. Besides the works 

 already mentioned, and a great number of con- 

 tributions to the Philosophical Transactions, Sir 

 Humphry Davy was author of Elements of i'h finical 

 Philosophy (1812); On the Stif,ti/-Iant}t in Coal- 

 iniiii'x (1818); HafinoHiti, or Days of Fly-fishing 

 (1828); and OuuoUM*M in Travel (1830) all in- 

 cluded in his Collected Works (9 vols. 1839-40). 



See Memoirs of the Life of Sir Humjthrii /AH-//, l>y his 

 brother, John Davy (1830); his t'rivimrntnni R, mains 

 ( 1858) ; the Lift by Dr Paris ( 1831 ) ;' and that by Dr T. 

 E. Thorpe (189G). 



Davy, JOHN, musician, was born near Exeter 

 in 1763, and died in London in 1824. Many of his 

 songs were great favourites, and though most are 



