HISTORY OF GALVANISM. 



the pile, beginning with those which are the least 

 powerful : water, muriate of soda, muriate of am- 

 monia, hyperoxymuriate of potash, sulphate of 

 alumine, and sulphate of iron. It is remarked, 

 that if the fluids differed in their action merely 

 in consequence of a difference in their conducting 

 power, the same effects should be produced by suf- 

 fering them to remain for a sufficient length of 

 time in contact, but on account of the changes 

 which take place in the state of the pile in other 

 respects it is difficult to ascertain this point. Sub- 

 stances generally have their electrical condition 

 altered when they undergo any change in their 

 state, and therefore the chemical action of the pile 

 will probably develop electricity, as well as the 

 action of the metals upon each other; but the 

 author is disposed to conclude that the effect of 

 the chemical change in the fluids is considerably 

 less than the electrical effect excited by the contact 

 of the metals.* 



In the year 1804, a very valuable memoir 

 was written by Hisinger and Berzelius, which MUS 

 must be regarded as containing the germ of those 

 doctrines, which have since been so extensively 

 developed by Sir Humphry Davy. By passing 

 the galvanic influence through solutions of the 

 different neutral salts, they found that there was 

 a transfer of the acid and alkali to different parts 

 of the apparatus. They formed the general con- 



* Ann. de Chim. xlvii. 1. 



