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Experiment I. 
The air produced from brown fugar and water, by 
fermentation, was caught in an inverted bottle of fope 
leys in the ufual manner, and which is reprefented in 
Fig. i. As the weather was too cold to fuffer the 
fugar and water to ferment freely, the bottle contain- 
ing it was immerfed in water, which, by means of a 
lamp, was kept condantly at about 8o° of heat. The 
quantity of fugar put into the bottle was 931 grains: 
it wasdidolved in about 6.1. times its weight of water, 
and mixed with 100 grains of yead, by way of fer- 
ment. The empty fpace left in the fermenting bottle 
and tube together meafured 1920 grains. The mix- 
ture fermented freely, and generated a great deal of 
air, which was forced up in bubbles into the inverted 
bottle, but was abforbed by the fope leys, as fall as it 
rofe up. It frothed greatly ; but none of the froth 
or liquor ran over. In about ten days, the fermen- 
tation feeming almod over, the veffels were feparated. 
The bottle with the fermented liquor was found to 
weigh 412 grains lefs than it did, before the fermen- 
tation began. As none of the liquor ran over, and as 
little or no moidure condenfed within the bent tube, 
1 think one may be well allured, that the lofs of 
weight was owing intirely to the air forced into the 
inverted bottle 3 for the matter difcharged, during the 
fermentation, muff have confided either of air, or 
of fome other fubdance, changed into vapour : if this 
laft was the cafe, I think it could hardly have failed, 
but that great part of thofe vapours mud have con- 
denfed in the tube. The air remaining unabforbed in 
the inverted bottle of fope leys was meafured, and was 
2 found 
