INFLUENCE OF GALYANlSM ON MINERALS. 2^7 



manner, the smell of sulphuretted hidrogen was perceived, acted upon in 

 and the water rendered turbid ; the slips of platinawere co- ne s r imi ar man " 

 loured, as in the former experiment, black on the negative 

 sides, and brownish yellow on the positive ; the water, which 

 was strongly acid, precipitated acetate of lead ; and the frag* 

 ments of the sulphurets were left in a state of division, al- 

 most pulverulent, and covered with pellicles of a dull colour 

 and without lustre. 



The sulphuret of iron in particular exhibited a very The su] pnuret 

 striking alteration on its surface. Having attached the con<- of iron inflame 

 ductors before water was put into the glass, the sulphuret 6 * 

 was vividly inflamed; which astonished us the more because 

 in a preceding expeiiment a fragment of transparent na-* 

 tive sulphur did not exhibit the least sign of inflammation, 

 when touched with the platina exciter undera jar rilled with 

 oxigen gas, though the battery was powerful enough to bum 

 the iron wire. 



It even appeared to us, in the last experiment, that the 

 inflammation of the sulphuret took place instantaneously 

 after it had been covered with water; but the effect was so 

 rapid, that we dare not assert this as a certainty. 



We purpose to pursue these experiments, and in the These experi, 



mean time I think I may conclude, that those of which I rinient V M 

 - . , . ., ' pursued. 



have just given an account, while they confirm my expla- 

 nation of the transition of brilliant crystallized sulphuret 

 of antimony to the state of an earthy yellow oxide, without 

 losing jts configuration, afford a new mean for interrogating 

 nature respecting the composition of bodies, the propor- 

 tions of their component parts, and the succession of chan- 

 ges effected in their combinations. The desulphuration of 

 ores is one of the most important points in metallurgy ; and 

 if, in the present state of our knowledge, we can scarcely, 

 discern any possibility of availing ourselves of this mean in 

 processes in the large way, those of assaying cannot fail to 

 '(thrive more certain results from its application. 



