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OBSERVATIONS and EXPERIMENTS undertaken with a view 

 to determine the QUANTITY of SULPHUR contained in SUL- 

 PHURIC ACID; and of this LATTER contained in SUL- 

 PHATES in general. By RICHARD CHENEVIX, F. R. S. 

 and M. R. I. A. 



4> 



1801. 



In a paper which I had the honour to prefent to the Royal Read, May 

 Society of London, and the fubjed of which was the analyfis 

 of fome arfeniates of copper, and of iron, I had occafion, in ex- 

 amining many pyrites, matrices of thofe ores, to remark the very 

 great inequality which prevailed in the refults of repeated ex- 

 periments, made with a view to determine the proportion of 

 fulphur. But I foon perceived, that the inaccuracy was caufed by 

 a partial combuftion and acidification of the radical, through the 

 means of the nitric acid, employed to diffolve the ore. 



Having therefore, in the ufual manner, afcertained what 

 quantity of that ingredient remained untouched, I was forced 



to 



