HISTORY OF GALVANISM. 29 



drogen, and that they were generated in the 

 proportion necessary to produce water. In some 

 of these experiments the spark was visible.* 

 Every one will be sensible of the important views 

 that were disclosed by the experiments related 

 in this paper, in connexion with those performed 

 by Mr. Cruickshanks of Woolwich, of which an 

 account will be given below. They must be re- 

 garded as leading directly to the wonderful dis- 

 coveries that have been made by means of the gal- 

 vanic apparatus, as well as the theoretical deduc- 

 tions to which it has given rise, and which have 

 produced almost a complete revolution in our ideas 

 of the action of bodies upon each other. 



Cruickshanks confirmed the observations ofcvuick- 

 Nicholson, respecting the actual appearance of p^mentsT 

 sparks and the decomposition of water. This last 

 process he varied in different ways. By employ- 

 ing the interrupted circuit with silver wires, and 

 -passing the influence through water tinged with 

 litmus, he found, that the wire connected with the 

 zinc end of the pile communicated a red tinge to 

 the fluid contiguous to it ; and afterwards, by em- 

 ploying water tinged with Brazil wood, he found 

 that the wire connected with the silver end of the 

 pile produced a deeper shade of colour in the sur- 

 rounding fluid. Hence it appeared, that an acid Acid and 

 was formed in the former, and an alkali in the lat- duced in" 

 ter case. The galvanic influence was passed tbe water ' 



* Nicholson's Journ. 4to. iv. 179. 



