cn the Production of DcpJjlogiJlic cited Air . <j j 
furniftiing air. To afcertain this fact, I took a globe A, fimi- 
lar to that made ufe of in the foregoing experiment, and having 
filled it with frefh fpring water, I introduced into it 30 grains 
of raw filk, and placing it with its cylindrical neck inverted 
in a jar filled with the fame water, I covered the whole with a 
large inverted earthen veflel, and expofed it, fo covered up, for 
feveral days in my window, by the fide of another globe B, 
containing a like quantity of water and filk, which I left 
naked, and confequently expofed to the direct rays of the fun. 
The refult of this experiment was, that the water and filk 
in the globe expofed to the fun’s rays furnifhed air in great 
abundance, as in the experiment before-mentioned ; while that 
in the globe covered up in darknefs, produced only a few 
very inconfiderable air-bubbles, which remained attached to the 
filk. 
Experiment N° 3. 
To fee if heat would not facilitate the production of air in 
the globe fheltered from the light, I now removed it from the 
window, and placed it near a German ftove, where 1 kept it 
warmed to about 9 o° of Fahrenheit’s thermometer for more 
than 24 hours ; but this was all to no purpofe. The air pro- 
duced was fo exceedingly fmall in quantity, that it could neither 
be proved, nor meafured, there being only a few detached air- 
bubbles, which had collected themfelves near the top of the 
globe. 
The medium heat of the water in the globe expofed in the 
fun’s rays, at the time when it furnilhed air in the greateil: 
abundance, was about 90° Fahrenheit. It was fometimes 
as high as 96°; but air was frequently produced in confiderabie 
quantities when the heat did not exceed 65 and 70 . 
N 2 
Ex be- 
x 
