DECOMPOSITION OF SULPHA.TE OF IIION BY ANIMAL MATTER, QW 



described, having the same yellow colour from an admi:c. 

 ture of sulphur, and a similar crust of this substance ad- 

 hering to one side. 



Any future traveller, visiting those countries, would do Probably a less 



•well to examine thera with a view to this paVticuIar obiect. ^are volcanic 



z J product than 



The boracic acid may be a more extensive volcanic product might be sup- 

 than has hitherto been imagined ; for in the account given Poscd. 

 of its discovery some years ago, by Messrs. Iloefer and 

 Mascagni, near Monte Rotondo, to the west of Sienna, 

 •we can have no doubt of its volcanic origin in those places, 

 from the substances which are there described to accom- 

 pany it. 



IX. 



Notice respectin-; the Decomposition of Sulphate of Iron 

 by Animal Matter: by W. H. Pepys, Esq. F. R, S. 

 Treasurer of the Geological Society*'. 



jl\S the following circumstance, that took place in my la- Mode in which 

 boratory, appears to throw considerable light on the mode ""f p"^ ^^.^^^ 

 whereby organic remains become penetrated by pyrites, it by pyrites, 

 may not perhaps be foreign to the objects of the Geological 

 Society ; and, as such, 1 have taken the liberty of oiTering 

 it to their attention. 



I was engaged a few years ago in a course of experi- A soluti»n of 

 mcnts on hidrogen gas, which was procured in the usual g^j^j^^^^'™-^ 

 method, by the solution of iron turnings in diluted sul- mal matter. 

 phuric acid. The sulphate of iron hence resulting, to the 

 amount of some quarts, was poured into a large earthen 

 pitcher, and remained undisturbed and unnoticed for about 

 a twelvemonth. At the end of this time, the vessel being 

 wanted, I was about to throw away the liquor, when my 

 attention was excited by an oily appearance on its surface, 

 together with a yellowish powder, and a quantity of small 

 hairs. 



The powder, on examination, proved to be sulphur j Results. 

 and on pouring off carefully the supernatant liquor, there 



*Tran<;, of theGcol. Soc. voj. i, p. 399. 



