112 Britain's Heritage of Science 



which illustrates his wonderful powers of intuition in hitting 

 on the essential points of an experiment : 



" Galvanism " (we should now call it " current 

 electricity ") "I have found, by numerous experiments, 

 to be a process purely chemical, and to depend wholly 

 on the oxidation of metallic surfaces, having different 

 degrees of electric conducting power. 



" Zinc is incapable of decomposing pure water ; and if 

 the zinc plates be kept moist with pure water, the galvanic 

 pile does not act; but zinc is capable of oxidating itself 

 when placed in contact with water holding in solution 

 either oxygen, atmospheric air, or nitrous or muriated 

 acid, etc., and under such circumstances the galvanic 

 phenomena are produced, and their intensity is in pro- 

 portion to the rapidity with which the zinc is oxidated." 

 Davy took up his position as Assistant Lecturer at the 

 Royal Institution in London, and so brilliantly did he 

 discharge his duties that his audience was taken by storm, 

 and the lecture room was soon filled with enthusiastic 

 listeners. The full title of lecturer was given him at 

 once, and the Philosophical Magazine predicted that " from 

 the sparkling intelligence of his eye, his animated manner, 

 and the ' tout ensemble,' we have no doubt of his attaining 

 a distinguished eminence." The control of the subjects to 

 be investigated rested at the time with the governing body, 

 and the Institution having been founded with a view to the 

 practical applications of science, the managers resolved that 

 Davy should give a course of lectures on the Principles of 

 the Art of Tanning; he received leave of absence during 

 three summer months for the purpose of making himself 

 acquainted with the subject. Subsequently he was requested 

 to devote his energies to agriculture, and the various duties 

 which the authorities of the Royal Institution imposed 

 upon him took up much time which would have been better 

 employed in research work. Nevertheless, he found sufficient 

 leisure to return to his favourite study, the chemical action 

 of electric currents, with the result that in 1806 he commu- 

 nicated a paper to the Royal Society which was made the 

 Bakerian lecture of the year. It constitutes a most impor- 

 tant contribution to science, and lays the foundation in 



