[ 1 77 ] 
found to be exactly equal to the empty fpace left in 
the bent tube and fermenting bottle. It appears 
therefore, that there is not the lead air of any kind 
difcharged from the fugar and water by fermentation, 
but what is abforbed by the fope leys, and which may 
therefore be reafonably fuppofed to be fixed air. It 
feems alfo, that no part of the common air left in the 
fermenting bottle was abforbed by the fermenting 
mixture, or fuffered any change in its nature from 
thence : for a fmall phial being filled with one part of 
this air, and two of inflammable air ; the mixture 
went off with a bounce, on applying a piece of lighted 
paper to the mouth, with exa&ly the fame appear- 
ances, as far as I could perceive, as when the phial was 
filled with the fame quantities of common and in- 
flammable air. 
The fugar ufed in this experiment was moifl, and 
was found to lofe parts of its weight by drying 
gently before a fire. Therefore the quantity of dry 
fugar ufed was 715 grains ; and the weight of the air 
difcharged by fermentation appears to be near 412 
grains, i. e. near _y_ parts of the weight of the dry 
fugar in the mixture. 
The fermented liquor was found to have intirely 
loft its fweetnefs ; fo that the vinous fermentation 
feemed to be compleated ; but it was not grown at 
all four. 
Experiment II. 
The air, difcharged from apple-juice by fermentation, 
was tried exa<£tly in the fame manner. The quantity 
fet to ferment was 7060 grains, and was mixed with 
100 grains of yeaft. Some of the fame parcel of 
Vol. LVI. A a apple- 
