r II. 5 1 
will be found under the fublimate, with fome drofs 
at the bottom 
Etiology of the Operation, 
As loon as the mixture grows warm, the tin adls 
on the fil ammoniac, and fets free its volatile alkali j 
and this, having a great affinity with fulphur, joins 
with a great part of it -f-, rifes in the fublimation, and 
is totally diffipated. The portion of tin, which 
aded on the Sal ammoniac and fet free its volatile al- 
cali, unites with the acid of fait of the fal ammoniac, 
and forms a fait of tin, which fublimesj. The 
mercury, which was added only in order to divide 
the tin, unites with fome of the fulphur, and like- 
wife fublimes and forms a cinnabar. The tin which 
remains, unites with the remaining fulphur, and 
forms the Aurum mofaicum, which is found in the 
bottom of the matrafs. Inftead of performing this 
operation in a matrafs, I have ufed a glafs retort, fixed 
in a black lead crucible, with land round it j the 
crucible was put into a proper furnace, and a charcoal 
* The proportion formely ufed was equal parts of each, which 
in. the quantity of tin here employed, viz, ^ 12, produced only 
^ 13I of Aurum mofaicum; whereas the fame quantity of tin 
in the proportion of the London difpenfatory afforded ^16, 
Troy weight was made ufe of in all the following experi- 
ments. 
t Sulphur combined with volatile alcali forms a volatile liver 
of fulphur, called by Mr. Boyle volatile tincture of fulphur and 
quick lime. 
i Filings of tin, calx of tin, or tin divided by amalgamation 
with mercury, diftilled with fal ammoniac, &c. decompofes it, 
whereby its acid of fait unites with the tin, and its volatile 
alkali is fet free, 
0^2 fire 
