[ 239 ] 
which it did not feem to have any affinity ; I im- 
mediately began to introduce a variety of fub- 
fiances to it, in order to afcertain its peculiar pro- 
perties and affinities, and alfo the properties of thofe 
other bodies with refpedt to it. 
Beginning with water, which, from preceding 
obfervations, I knew would imbibe it, and be- 
come impregnated with it 3 I found that 2f grains 
of rain water abforbed three ounce meafures of this 
vapour, after which it was increafed one third in its 
bulk, and weighed twice as much as before ; fo 
that this concentrated vapour feems to be twice as 
heavy as rain water. Water impregnated with it 
makes the flrongefl fpirit of fait that I have feen,, 
diffolving iron with the mofl rapidity. Confe- 
quently, two thirds of the befl fpirit of fait is no- 
thing more than mere phlegm. or water. 
Iron filings, being admitted to this vapour, were 
diffolved by it pretty faff, half of the vapour dis- 
appearing, and the other half becoming inflammable: 
air, not abforbed by water. Putting chalk, to it,, 
fixed air was produced. 
L had not introduced many fubflancesto this va<- 
pour, before I.difcovered that it had an affinity with: 
phlogiflon, fo that it would deprive other fubftances . 
of it, and form with it fuch an union as conftitutes- 
inflammable air ; which feems to fhew, that inflam- 
mable air univerfally confifts of the union of fome- 
acid vapour with phlogiflon. 
Inflammable air was produced, when to this^ 
vapour I put fpirit of wine, oil of olives,, oil o£ 
turpentine, charcoal, phofphoruSj bees- wax, and; 
even fulphur. This laft obfervation, I. own, fur- 
prized: 
