on Hepatic Air • 137 
inflammable air undoubtedly proceeding from the folution of 
the iron. 
Five cubic inches of faccharine hepatic air, mixed with 5 of 
alkaline air, were diminifhed more (lowly 5 for after five mi- 
nutes there ftill remained 4,5 cubic inches. I then added ano- 
ther meafure of alkaline air : in three hours after there re- 
mained but 1,25 cubic inches. In paffing this refiduum through 
water it was reduced to about half a cubic inch ; and this 
burned with a blue lambent flame, without leaving a vitriolic 
fmell or any depofit on the glafs ; fo that it clearly was inflam- 
mable air from the fugar. 
I once imagined I had obtained inflammable air from a mix- 
ture of alkaline air with hepatic air drawn from liver of ful- 
phur; but I afterwards found this inflammable air proceeded 
from a very flight contamination of zinc in the mercury over 
which my airs had been produced ; the alkaline air adted on 
this zinc, and muft have produced the inflammable air; for 
when I afterwards received and mixed thefe airs over mercury, 
perfedtly purified, I obtained no more inflammable air. 
SECTION IV. 
Of the Adlion of Hepatic Air , and Acid , Alkaline , and Inflam- 
mable Liquids , on each other . 
One meafure of oil of vitriol, whofe fpecific gravity was 1,863, 
abforbed two meafures of hepatic air all to one-tenth. The acid 
was whitened by a copious depofition of fulphur. I alfo intro- 
duced, over mercury, a meafure of red nitrous acid, whofe fpeci- 
fic gravity was 1,430, to an equal meafure of hepatic air; red 
Vol.LXXVI. T vapours 
