on the Production of Dephlogijhcated Air. ^ 
and 6 wax-candles, placed at different diftances from 3 to 6 
inches from it, and fo dilpofed as to throw the greateft quan- 
tity of light poffible upon the filk in the water, taking care at 
the fame time that the water fhould not acquire a greater heat 
than that of about 90° F. 
Things had not remained in this ftuation above 10 minutes, 
when I plainly difcovered the air-bubbles beginning to make 
their appearance upon the furface of the filk ; and at the end 
of 6 hours, there was collected at the upper part of the globe 
a quantity of air fufficient to make a proof of its goodnefs with 
nitrous air; and, upon trial, I had the pleafure to find, that it 
was dephlogiflicated , and of fuch a degree of purity, that 1 
meafure of it with 3 meafures of nitrous air occupied no more 
than 1,68 meafure. 
I afterwards expofed, to the fame light, in fmall inverted 
glafs jars, filled with water, a frefh-gathered healthy leaf of 
the peach tree, and a flem of the pea plant with 3 leaves upon 
it ; and both thefe vegetables furnifhed air in the fame manner 
as they are known to furnifh it when expofed, under fimilar 
circumflances, to the adlion of the fun’s diredl rays, but in lefs 
quantities, which I attribute to the greater intenfity of the 
fun’s light above that of my lamps. 
The experiment with the (ilk and water I repeated feveral 
times, always with nearly the fame refult. The quantity of 
air furnifhed was fometimes a little greater, and fometimes a lit- 
tle lefs ; but it was always in much greater abundance than that 
furnifhed by an equal quantity of water and lilk expofed to the 
fame heat, but excluded from the light ; and I have reafon to 
think, it was of a much fuperior quality, though the quantity 
of that produced in the dark was too fmall to be fubmitted to 
any proof, 
I 
Thefe 
