HISTORY OF GALVANISM. 



Wollas- 

 ton's ele- 

 mentary 

 battery, 

 1815. 



merits which he performed of a similar nature 

 generally tended to the same conclusion. The 

 facts stated in this paper are conceived to be fa- 

 vourable to the hypothesis of Sir H. Davy, respect- 

 ing the natural electricities of bodies, and also, 

 when viewed in connexion with Erman's observa- 

 tions, to afford an additional proof of the identity 

 of electricity and galvanism.* 



Mr. Brande's method of viewing these experi- 

 ments is, I conceive, preferable to that of the 

 author himself, as being more simple, and as in- 

 volving no principle in addition to those which are 

 deduced from other phenomena. In most cases at 

 least it offers a satisfactory explanation of the facts ; 

 and it does not appear, in any instance, to be 

 directly at variance with them. 



Dr. Wollaston constructed a very curious appa- 

 ratus, which he calls an elementary galvanic bat- 

 tery, the object of which is to exhibit the most 

 minute arrangement of electrical substances, by 

 which visible ignition can be produced. The 

 smallest that he has constructed consists of a 

 thimble, without its top, flattened until its sides 

 were about one-fifth of an inch asunder ; a small 

 plate of zinc was then contrived to be fixed within 

 the thimble, but without touching it ; and a pro- 

 per appendage of platina wires was added. The 

 zinc plate was less than three-fourths of an inch 

 square, and even when water was employed that 



* Phil. Trans, for 1814-. 



