254* INFLUENCE OF GALVANISM ON MINERALS. 



sia, I was led to consider this mineral as a transition from 

 the state of a sulphuret to that of almost a pure oxide, 

 which conM have been effected only by the decomposition 

 of water, determined 'by a subterranean electricity precisely 

 similar to that we obtain in Volta's apparatus. • 



This shown bv The external appearance of this mineral, which still evi- 

 its appearance dently exhibits the structure of native crystallized sulphuret 

 of antimony, and even in some parts the remains of a me- 

 tallic lustre, leaves no doubt, that its entire mass was origin- 

 ally a sulphuret of antimony, the particles of which had un- 

 dergone the slow and successive action pf some agent, that 

 had altered their composition, without disturbing their re- 

 spective arrangement, precisely as we see in petrified wood, 

 that retains its organization. 

 The principle The proofs on which I grounded this explanation, and 



applicable to t] ie applications I have made of this principle to- the forrna- 

 other fossils. . , . „ ., , . , , 



tion of other fossils, as the pyrites termed hepatic, gray 



copper ore, &c, have been detailed in a paper inserted in 

 the Journal of the Polytechnic School, for July, 1802., p. 

 308. 

 Mr. Davy's Mr. Davy's views on the same subject, given at the end 



ideas similar. c f ]^ s excellent Bakerian lecture read to the Royal Society 

 on the ooth of November, 1806, where he speaks of the 

 slow and silent operations of natural electricity even on the 

 mineral system*, inspired rne with the idea of endeavouring 

 to corroborate the inferences drawn from my former results, 

 by performing the experiments with the more powerful ap- 

 paratus, which we at present possess. 

 _ . I^lessrs. Hachette and Clement were so good as to assist 



confirm the me in this undertaking. We formed a battery of 64 plates 

 fact - of copper and zinc, 15 cent, [near ti inches] long by 10 



cent, [near 4 inches] broad, affording a surface of go'OO cent, 

 or about 1260 French inches square. 

 Apparatus. This battery was arranged in Mr. van Marum's manner, 



that is, distributed in four piles, the first two of which were 

 placed in a plate of copper with its edges turned up, and 

 Supported by an insulator. The pasteboards placed between 

 pairs of metal were wetted with a strong solution of soda. 

 Sulphuret of A piece of sulphuret of antimony was placed in a small 



* S^.'c Journal, vol. XIX, p. 62. 



glass 



