194 F. H. Storer on Nitric Acid and Chiorate of 
filtrate from silica was acidulated with chlorhydric acid without 
the addition of tartaric acid, there was thrown down on the 
addition of chlorid of barium a bright yellow precipitate 
which became darker colored when the solution was boiled. It 
was not cnly found to be impossible to wash out the iron with 
which this precipitate was contaminated but the consistency 
of the precipitate was such that it was a difficult matter even 
to wash away the saline liquor in which the precipitate was 
destroy the tartaric acid by igniting the dried filtrate, from 
sulphate of barium, in a muffle, for on evaporating this solu- 
tion the saline matters with which it is charged continually 
creep over the edges of the dish. 
November, 1868. 
Assay of Copper pyrites ; by F. P. Pearson. 
The following method of treating copper pyrites has been 
found more advantageous than the UeditiaPy process of oxyd- 
izing the mineral with aqua regia and subsequently ede it 
, or wit 
Te a ne a eS ey, tre ae eee tae ea 
