[ 1 55 ] 
It was before faid, that one grain of zinc yielded 3 56 
grain meafures of air: therefore 254 grains of zinc 
yield 90427 grain meafures of air ; which we havejuft 
found to weigh 104 grains; therefore inflammable air 
is about 8410 times lighter than water, or 10' 
times lighter than common air. 
The quantity of moifture condenfed in the pearl- 
afhes was found to be about 14 grains. 
By another experiment, tried exactly in the fame 
way, the denfity of inflammable air came out 8300 
times lefs than than that of water. 
The fpeciflc gravity of the air, produced by diflolv- 
ing zinc in fpirit of fait, was tried exactly in the fame 
manner. 244 grains of zinc being diflolved in fpirit of 
fait diluted with about four times its weight of water, the 
lofs in effervefcence was 104 grains; the empty lpace 
in the bottle and cylinder was 914 grain meafures; 
whence the weight of the inflammable air was 94 
-grains, and confequently its denfity was 89 10 times lefs 
than that of water. 
By another experiment,- its fpeciflc gravity came out 
9030 times lighter than water. 
A like experiment was tried with iron. 2504 grains 
of iron being diflolved in oil of vitriol diluted with four 
times its weight of water, the lofs in effervefcence 
was 13 grains, the empty fpace 1420 grain meafures. 
Therefore the weight of the inflammable air was 1 14 
grains i. e. about of the weight of the iron, and its 
denfity was 8973 times lefs than that of water. The 
moifture condenfed was 14 grains. 
A like experiment was tried with tin. 607 grains of 
tinfoil being diflolved in ftrong fpirit of fait, the lofs 
in effervefcence was 144 grains, the empty fpace 873 
X 2 grain 
