, H Dr. Priestley's Experiments relating to Phlogiflon, 
form of powder. By this means it would eafily pour out of 
the retort when the experiment was over. 
The weight of the water expended in this produftion o ai 
I afcertained, in the mod unexceptionable manner, oy weig - 
in* the retort, with all its contents, before and after the pto- 
ce fs. I (hall explain this by the refult of two of the proceBes. 
In one of them, the retort and moiftenec! clay togrf o o t ... 
weight t oz. 4 dwts. 1 2 grs. after yielding 74 « ounce meafures 
of air, which (in the proportion of fix grains to one ounce 
meafure) would have weighed 18 dwts. 12 grs. and cot 
quentlv three-fourths of the weight of the water. 
In the other procefs the lofs of Weight Was 15 dwts. to grs. 
after yielding 556 ounce meafures of air, rvhich would have 
weighed 1 3 dwts. 21 grs. The proportion, theiefoie, between 
the weight of the air and that of the water- was m to no, 
or nearly nine to ten. 
I alfo found now, that fo much heat as I had hitherto ap- 
plied was neither neceffary nor ufeful. In the laft mentioned 
procefs the retort was conftantly fefpended about fix rnche* 
above a moderate charcoal fire; at another time more t an 
twelve or fifteen inches above it, where a fahkmeit s 
thermometer did not Ihew more than 2 to”. With this 
moderate heat I got 465 ounce meafures m the cou.fe o 
about twelve hours. When the retort was fufpended within 
fix inches of the fire, the air was generally produced a le 
rate of 30 ounce meafures in five minutes. But a thermome- 
ter, the bulb of which was immerfed in the clay, was ftilt 
only at the heat of boiling water. t 
In all thefe process, however, there was evidently fome 
lofs of water ; for, excepting the firft experiment with the 
lime, I never got the whole weight of the water m air ; and 
