on Hepatic Air. 139 
no longer detonated, but burned with a blue and greenifh 
flame, and fulphur was depofited on the fides of the jar. 
Obferving this dilute acid to abforb nearly three times its 
bulk of alkaline hepatic air, I expelled this air from it by heat, 
but obtained only one-fixth of the air that had been abforbed; 
and in this a candle burned naturally. 
Two meafiires of alkaline hepatic air, being expofed to one 
of ftrong marine acid. , were abforbed* by flight agitation, ail to 
one-fifth of a meafure. A third meafure of air being then 
added, there remained, after fome agitation, but half a mea- 
fure. Sulphur was precipitated as ufual ; but the mercury 
over which the acid flood attracted it from the acid ; for it was 
blackened, which did not happen when the former acids were 
ufed. The refiduum burned juft as pure hepatic air. 
Dijiilled vinegar abforbs nearly its own bulk of air, and be- 
comes llightly whitened ; but by agitation it may be made to 
. take up about twice it bulk, and then becomes very turbid. 
©ne meafure of caujlic vegetable alkali , whofe fpecific gra- 
vity was 1,043, abforbed nearly four meafures of alkaline he- 
patic air. It was at firft rendered brown by it ; but after fome 
time it grew clear, fulphur was depofited, and the furface of the 
mercury blackened. This fhews that alkalies are not dephlo- 
gifticated by filver or other metals, as Mr. Baume imagined, 
but only cleared of part of the fulphur, which they commonly 
contain, it being formed by the tartar vitriolate contained in 
the plant, and coal, during combuftion. 
One meafure of caujlic volatile alkali, whofe fpecific gravitv 
was 0,9387, abforbed 18 of hepatic air. If the cauftic liquor 
contained more alkali, it would abforb more hepatic air, as 6 
meafures of hepatic unite to 7 of alkaline air ; and thus the 
ftrength of alkaline liquors, and thqxr real contents, may be 
T 2 determined 
