HISTORY OF GALVANISM. 55 



of electricity, but which may be rendered electri- 

 cal, by being placed in contact with the primary 

 pile. When the two piles are connected, the 

 action of the ends of each are reversed to each 

 other, and as when they are separated, the ends of 

 the secondary pile are again reversed, consequently 

 the ends of both the piles will now act in the same 

 manner. It is necessary for the pile of Ritter to 

 remain for some time in contact with the pile of 

 Volta, in order that it may be sufficiently charged. 

 It is stated that the chemical effect of Hitter's Effects. 

 pile, that is, its effect in decomposing water, does 

 not bear a regular ratio to its physiological effect, 

 that is, its effect in giving shocks. The author ob- 

 serves, with respect to the voltaic pile, that its 

 tension is the greatest, and it produces the strong- 

 est effects on the sensations, immediately after it 

 is constructed, but that its chemical effects are the 

 most powerful after it has been acting for some 

 hours.* 



Shortly after the publication of the account of Farther ex. 

 the secondary pile, Ritter made a number of expe- 

 riments with the pile of Volta, which are original J 

 and curious. He observed that when a communi- 

 cation was formed between the positive end of the 

 voltaic pile and the earth, the whole instrument 

 became negatively electrified, and when the com- 

 munication was made with the negative end, the 

 instrument became positive. These changes do 



* Journ. de Phys. Ivii. 34?5. 



