3 3 5 >/. 
on Hepatic Air • 1*25 
fary acid; but when I filled the retort with air phlogiflicated 
by the nitrous teft unto 1,8, and in this air diftilled the above 
mixture, the refult was exactly the fame as when the retort 
was filled with atmofpheric air. 
Six grains of pyrophorus , made of alum and fugar, effer- 
vefced with marine acid, and afforded 2,5 cubic inches of he- 
patic air. This pyrophorus had been made fix years before, 
and was kept in a tube hermetically fealed, and for many fum- 
mers expofed to the flrongeft light of the fun. It was fo com- 
buftible, that fome grains of it took fire while it was intro- 
duced into the phial out of which the hepatic air was expelled. 
A mixture of two parts white fugar (previoufly melted in 
order to free it from water) with one part fulphur, when heated 
to about 600 or 700 degrees, gave out hepatic air very rapidly. 
This air had a fmell much refembling that of onions ; it con- 
tained no fixed air, nor faccharine, or other acid. But fugar 
and fulphur, melted together, gave out no hepatic air when 
treated with acids. Water, fpirit of wine, and marine acid, 
decompofe this mixture, diffolving the fugar, and leaving the 
fulphur. 
A mixture of fulphur and plumbago afforded me no hepatic 
air. 
I then tried whether fulphur could combine with elaftic 
fluids, and the refults were as follows. 
12 grains of fulphur, heated in a retort, filled with metallic 
inflammable air, afforded no hepatic air ; though when the retort 
was cold, and for fome time expofed to the air, it fmelled of 
hepatic air. It is true, the heat I applied might be infufficient ; 
for the inflammable air paffing over with a flight heat, the 
mercury afcended fo high into the neck of the receiver, that, 
fearing the rupture of the retort, I was obliged to interrupt 
the 
