40 HISTORY OF GALVANISM. 



tallic leaves. He formed an instrument of large 

 plates of zinc and copper, and fixed gold leaf to 

 the zinc end ; then by bringing it in contact with 

 the silver end, the leaf was rapidly consumed, 

 the process being attended by a beautiful emission 

 of coloured light. Silver, tin, and copper leaves 

 were burned in the same manner, each giving out 

 a brilliant flame tinged by its appropriate colour.* 

 In a subsequent set of experiments he even suc- 

 * ceeded in burning the metals in the different gases 

 which contained no oxygen, but we are not fully 

 informed what was the exact nature of the pro- 

 ducts obtained in this case. Experiments on the 

 combustion of metals were performed about the 

 same time by Fourcroy, Thenard, and Vauquelin, 

 when they observed, that the energy of the shock 

 and the power of decomposition were not increased 

 The effect by the size of the plates, but by the number of 

 the repetitions ; while the same extent of surface, 

 arranged in the form of a few large plates, readily 

 consumed the metallic leaves, but had only a com- 

 paratively small effect on the sensation s.f Four- 

 croy, at this period of the investigation, supposed 

 that the galvanic phenomenona could not be refer- 

 red to the action of electricity ; but this opinion 

 he was afterwards induced to retract. Indeed this 

 point was shortly afterwards established beyond 

 dispute by Mr. Cruickshanks actually charging the 



* Nicholson's Journ. 4to. v. 238. 

 Ann. de Chim. xxxix. 103. 



