12 Biographical Memoir of Sir Humphry Davy. 



densation of gases as mechanical agents * ; finally, the colour 

 of the water of rivers and of the ocean -f- ; were subjects that at- 

 tracted his attention, and produced instructive and interesting 

 papers. 



Particular mention ought to be made of the course of lectures 

 which he delivered before the Board of Agriculture in 1803, 

 and which were published in 1813 J. It was thus that a young 

 man of twenty-two, who had no practical experience of the 

 subject, unexpectedly enlightened the proprietors and most 

 experienced cultivators in Great Britain. 



Such occupation, however, as we have been alluding to, may 

 be said to have formed only a kind of diversion from his severer 

 studies. His experiments on the decomposition of bodies by 

 galvanic electricity were of a superior order, and it was to them 

 that he owed his sudden elevation, by the unanimous voice of 

 Europe, to the rank of one of the first chemists of our age. No 

 one will dispute that there was never displayed, in such a length- 

 ened investigation, a greater degree of perseverance, method, 

 and precision ; and rarely have these qualities been crowned 

 with more brilliant success. 



An observation casually made by Galvani in 1789, in which 

 he had seen the parts of a dead animal become convulsed when 

 a metallic communication was established between a nerve and 

 the muscle, had excited the attention not only of the learned but 

 of the vulgar : some believed that they saw in it the explanation 

 of all the vital phenomena, and the means of recalling even 

 the dead to life. Volta referred these facts to their true cause, 

 viz. the electricity produced by the contact of two metals ; and, 

 in his endeavours to render the influence of the metals more 

 considerable, he increased the number of the plates, and se- 

 parated them by others of less conductive power ; thus c on- 

 structing his famous pile, the constant source of an electricity 



• Roy. Soc. Lond. 27th April 1823; Phil. Trans, v. cxiii. p. 193; Ann. de 

 Chim. et de Phys. torn. xxv. p, 80. 



t Salmonia (2d edit), p. 316 ; Bibl. Univ. torn. xl. p. 114. 



X Elements of Agricultural Chemistry, in a Course of Lectures for the 

 Board of Agriculture, 4to and 8vo, Lond. 1813. Translated into French, 

 12mo, Paris 1820, and into Gennan, by F. Wolf, with additions by A. Thaer, 

 8vo, Berlin 1814. 



