*26$ INFLUENCE OF GALVANISM ON MINERALS* 



tion of a few hoars cannot be perfectly similar to that of 

 another, the duration of which depends on a uniform suc- 

 cession of agents, and the slowness of which prevents ail 

 possibility of its being- disturbed. 

 Nothing but If now we consider, that no one of the substances, which 

 frtdwcould " we ma y reasona bly presume to exist in the bowels of the 

 have wrought Earth, acts iu a similar manner, or produces the same chan- 

 1 e ange. ^ g ^ su |p nuret j* antimony when once formed, as I have 

 shown in the paper printed in the Journal of the Polytech- 

 nic: school, there appears to me no doubt, that the transiti- 

 on of the sulphuret of antimony of the province of Gallicia 

 to the state of native oxide (iu which it loses more than 0*17 

 of sulphur, and acquires 0*18 of OX i gen) results directly 

 from the decomposition of water by galvanic electricity. If 

 jt be strictly possible for the same effect to be produced by 

 a diiferent cause, it is certain, that the instances arc much 

 more rare, than is commonly supposed; and that the greater 

 number appears to belong to this class only because we con- 

 found the remote with the immediate cause, the process 

 with the chemical action, the form of the agent with the na- 

 ture, and, if I may be allowed the expression, the haudle 

 with the tool. But when the effect is characterised, as in 

 this particular case, by circumstances that imprint on it the 

 seal of a djstinctcause, and excludesany other known cause, 

 we have not a probability only, the certainty of the cause is 

 ecmal to the certainty of the effect. 

 Farther prov- We have since sought for new proofs of this conclusion, 

 ed > extending our experiments to other minerals, where the 



signs of a transition of this kind were most manifest, 

 on sulphuret ^ulphuret of iron, poor in metal, hard, compact, mid of 

 of iron, great lustre, merited attention in this point of view more 



particularly, because the pyrites of Berezoff, which is found 

 in the same state of alteration, in its primitive state resists 

 the action of the most powerful solvents, yielding only to 

 the nitric acid and the nitro-muriatic. 



On a pyrites of this kind, and the gray silver ore (crys- 

 ore. t'dWnedfahterzJi we endeavoured to produce analogous al- 



terations. 

 These exposed Bting exposed in distilled water to the action of the same 

 in water to a Igt&rjfi and communications established in a similar 



battery, were 



*' manner. 



