on the Pro Juft ion of Dephlogifticatcd Air. joj 
properties of all others the moftneceffary to its Supplying the 
place of filk in the produ&ion of air, by expofmg it in water 
to the a&ion of the fun’s rays. I therefore loft no time in 
making the following experiments. 
Experiment N° 16. 
The great globe (contents 296 cubic inches) being filled 
with frefh fpring water, and 120 grains of poplar cotton, 
upon the evening of the 9th of June, and being the next day, 
the 10th of June, expofed to the fun about four hours, upon 
the morning of the nth the air produced was removed, and 
its quantity was found to be i|- cubic inch. Its quality was 
very bad, viz. 1a 4- in rz 1 ,65, or 35 degrees only better than 
thoroughly phlogifficated air. 
Upon the l ith, 12th, and 13th, 1 cubic inch of air only 
was produced, and this appeared to be as bad as poffible ; for, 
proved with nitrous air, it gave 1^4- m— 2, or o. 
Upon the 14th a few air-bubbles only were furnifhed; but,* 
notwithstanding thefe unfavourable appearances, I lfill conti- 
nued the experiment, and my patience was amply rewarded ; 
for the next day, the 1 5th, the fun being very powerful, and 
the weather very hot, the water changing fuddenly to a green ifh 
colour, began all at once to give good air in great abundance. 
In the courfe of the day 10-YV cubic inches were produced, 
which, proved with nitrous air, gave 1^ + 3;;= 1,43, or 257. 
June 1 6th, a very warm clear day. The globe expofed in 
the fun, from 8 o’clock in the morning till 5 o’clock in the 
afternoon, furnifhed 14-rYo cu kic inches of air, which, proved 
with nitrous air, gave ia + $n = i, 34 > or 2 ^ 6 . 
Vol. LXXVII. 
V • 
p 
June 
