Parts of Water and of Dephlogifticated Air. 331 
heat *.) ‘‘ He found, that by expofing the calces of metals 
« to the folar rays, concentrated by a lens, in a veffel contain- 
«ing inflammable air only, the calces of the fofter . metals 
<*¢ were reduced to their metallic ftate;” and that the inflam- 
mable air was abforbed in proportion as they became phlogifti- 
cated; and, by continually fupplying the veflel with inflamma- 
ble air, as it was abforbed, he found, that out of 101 ounce mea- 
fures, which he had put. into the veflel, 99 ounce meafures were 
abforbed by the calces, and only two ounce meafures remained, 
which, upon examination, he found to be nearly of the fame 
quality the whole quantity had been of before the experiment, 
and to be ftill capable of deflagrating in conjunction with at- 
mofpheric or with dephlogifticated air. Therefore, as fo great a 
quantity of inflammable air bad been abforbed by the metallic calces ; 
the effect of reducing them to their metalhe fiate bad been produced; 
and the fmall remaining portion was full unchanged, at leaf had 
fuffered no change which might not be attributed to its original want 
of purity; it was reasonable to conclude, that inflammable air muft be 
the pure phlogifion, or the matter which reduced the calces to 
metals. ; 
2. * The fame ingenious philofopher mixed together cer- 
‘¢ tain proportions of pure dry dephlogifticated air and of pure 
<¢ dry inflammable air in a ftrong glafs veffel, clofely thut, 
<¢ and then fet them on fire by means of the eleCtric {park,” 
in the fame manner as is done in the inflammable air piftol. 
*¢ The firft effect was the appearance of red heat or inflamma- 
* Previous to Dr. Priesriey’s making thefe experiments, M. Kirwan had 
proved, by very ingenious deductions from other facts, that inflammable air was, 
in all probability, the real phlogifton, im an aerial form. Thefe arguments were 
perfectly convincing to me; but it feems more proper to reft that part of the 
 prefent hypothefis onthe direct experiment. 
Nx 2 : “¢ tion 
