INFLUENCE OF GALVANISM ON MINERALS. 265 



glass two thirds full of distilled water, and a communication antimony ex- 



grata established between the water and the two poles of the p0 * i€ ° 



buttery by means of two slips of platina, 



As soon as the bubbles began toannounce the decomposi- Sulphuretted 



hidvoeea 

 tion of the water, a slight smell of sulphuretted hidrogen evolved. 



was perceptible. In two hours this smell was very strong., 



the water had assumed a yellow tint, and the surface of the 



sulphuret of antimony appeared of a deeper yellow, and as 



it were iridescent. 



The slips of platina from the two poles were first fixed silver taraisfe* 

 at some distance from the sulphuret; afterward they were ed b y il * 

 brought near enough to touch it, apd the acceleration of the 

 disengagement of bubbles showed, that the activity of the 

 frattery had not slackened. 



After the expiration of four hours, the smell of sulphu- 

 retted hidrogen was perceptible at a distance. A slip of 

 silver, well cleaned, being placed on the edge of the glass 

 without touching the water, was in a few minutes covered 

 with a deep black coating. A drop of the water in the glass Acetate of 

 immediately formed a white, precipitate in a solution of ace- lead P^-'P 1 **- 

 tate of lead. 



That part of the slip of platina, which was connected The platina 

 with the negative pole and immersed in the water, was tarnished. 

 black : and that which communicated with the positive 

 pole had a slight yellow incrustation. 



The battery having lost almost the whole of its activity The sulphuret 

 at the expiration of eight hours, we attempted to take the covered Ith 

 piece of sulphuret out of the water; but the motion sepa- jer"™ P ° W " 

 rating part of the yellow powder that covered it, to collect 

 this we were obliged t© throw the whole upon a filter. 



This powder, dried in the air, exhibited the same reddish re semblir.sr the 

 yellow tint as the native oxide of the province of Gallicia; native oxide, 

 and the fragment still retained evident traces of it on several 

 poiuts of its surface, when scarcely any remains of metallic 

 lustre were distinguishable. 



Hence we may presume to give this product of our imi- , ,. ff . 

 • tation of the processes of nature as differing from the mo- onlv from the 

 dels she presents us only because the portion decomposed <,lffL ' ren(!e . of 

 had not reached the same depth, and acquired the same 

 consistency ; iu other words, because the result #f an opera- 

 tion 



