S6 Sir Benjamin Thompson’s Experiments 
Experiment N° i. 
My firft objeCl was to collet a fufficieilt quantity of the ah* 
feparated from water by lilk to determine its goodnefs by the 
tefl of nitrous air; and to this end, having filled with clear 
ipring water a globe of thin, white, and very tranfparent 
glafs, 4 1 inches in diameter, with a cylindrical neck f of an 
inch in diameter, and about 1 2 inches long, I introduced into 
it grains of raw filk, which had been previoufly wafhed in 
water, in order to free it of air ; and inverting the globe under wa- 
ter, and placing its neck in a glafs jar, containing a quantity of 
the fame water with which the globe was filled, I expofed it 
in my window to the aCtion of the fun’s rays, and prepared 
myfelf to examine the progrefs of the generation or production 
of the air. 
The globe had not been expofed ten minutes to the aCtion of 
the fun’s rays, when I difcovered an infinite number of ex- 
ceedingly fmall air-bubbles, which began to make their ap- 
pearance upon the furface of the filk ; and thefe bubbles con- 
tinuing to increafe in number, and in fize, at the end of about 
two hours the filk, appearing to be intirely covered with them, 
rofe to the upper part of the globe. 
Thefe bubbles going on to increafe in fize, and running into 
each other, at length began to detach themfelves from the filk, 
and to form a collection of air at the upper part of the globe ; 
but the meafure of my eudiometer being rather large, it was 
not till after the globe had been expofed in the fun near four 
days, that a fufficient quantity of air was collected to make the 
experiment with nitrous air, in order to afcertain its goodnefs by 
that teft. 
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