' t i r 8 ] 
V, Experiments on Hepatic Air . 
By Richard Kirwan, Efq. F. R* S* 
Read December 22, 1785. 
H EPATIC Air is that fpecies of permanently elaftic fluid 
which is obtained from combinations of fulphur with 
various fubftances, as alkalies, earths, metals, &c. It pof- 
fefles many peculiar and diftind: properties ; among which the 
moft obvious are, a difagreeable charaderiftic fmell emitted by 
no other known fubftance ; inflammability, when mixed with 
a certain proportion of refpirable or nitrous air ; mifcibility with 
water, to a certain degree ; and a power of difcolouring me- 
tals, particularly filver and mercury. Thefe properties were 
firft difcovered by that incomparable anaiyft M. Scheele. 
This air ads an important part in the oeconomy of nature* 
It is frequently found in coal-pits ; and the truly excellent and 
ever to be regretted M. Bergman has fhewti it to be the 
principle on which the fulphureous properties of many mineral 
waters depend, and thus happily terminated the numerous 
flifputes which the obfcurity of that fubjed had occafioned. 
There is alfo great reafon to think, that it is the peculiar pro- 
dud of the putrefadion of many, if not all, animal fubftances. 
Rotten eggs and corrupt water are known to emit the fmell 
peculiar to this fpecies of air, and alfo to difcolour metallic fub- 
ftances 
