348 Experiments in Galvanic ^leBricity. 



now fulfil my promife of writing to you; and having nothing 

 better at prefent to communicate, fequeft your acceptance of 

 the following fafts, refults of fome experiments, which, with 

 the aid of Mr. Nicol, I have lately made in my leifure hours, 



ift, When 72 fquare pieces of copper, 73 of zinc, and 71 

 of moiftened pafteboard, each containing four fquare inches, 

 and not exceeding in thicknefs i-i6th of an inch, w<^re 

 formed into a column by being applied to each other in the 

 Galvanic ferles, vix. zinc, copper, pafteboard — zinc, copper, 

 pafteboard, &c. &c., the column, though entirely compofed 

 of oxydable materials, difcovered a ftrong Galvanic power. 

 When the bottom of the column was touched with one 

 hand, and the top at the fame time with the other, both 

 hands being wet with brine, a fhock was felt fully as ftrong 

 as that which was given by an ele£lrical jar having 80 

 fquare inches of coated furface. Hence it appears that filvcr, 

 or a non-oxydable metal, is by no means effential to the 

 excitation of the Galvanic power ; and indeed I apprehend 

 that a Galvanic column, confifting of copper, zinc, and 

 pafteboard, will be found as povierful as an equal column 

 confifting of filver, zinc, and pafteboard. The above column, 

 confifting of copper, zinc, and pafteboard, retained its power 

 with little diminution during a period of 36 hours. 



2nd, When pieces of copper, zinc, and moiftened alumina 

 were formed into a column by being applied to each other in 

 the Galvanic feries, viz. zinc, copper, alumine, &c. the 

 column gave fliocks remarkably ftronger than thofe it would 

 have given had pafteboard been ufed. Hence a feries of 

 curious experiments fpontaneoufty prefent themfelves, de- 

 manding to be tried. Hence a probability that the Galvanic 

 power may fometimes occur among the ftrata of the earth; 

 and hence a new theory of earthquakes will in all probability 

 ere long appear, 



3rd, When the alumine in the Galvanic column was 

 moiftened with brine, inftead of water, the furface of the 

 column became, in the courfe of three or four days, covered 

 •with a copious white efflopefcence, which when collecled and 

 examined proved to be foda nearly faturated with carbonic 

 acid. A like efflorefcence was found in a column, in the 



cojiftru6lion 



