ATMOSPHERICAL AIR. 7 



of nitrous air by nitrous acid is attended with a confi- 

 derable degree of heat. 



That phlogifticated air, or azote, is not a fimple fub- 

 ftance, but confifts of phlogifton (or whatever is the 

 proper element of inflammable air) and of dephlogif- 

 ticated air, is probable from feveral experiments that 

 feem to have been overlooked by the antiphlogilfians, 

 fuch as the following. A mixture of dephlogifticated 

 and inflammable air being kept a long time was found 

 by M. Metherie to contain a confiderable portion of phlo- 

 gifticated air, as appeared by the difference of the refi- 

 duums after exploding a part of the mixture when firft 

 made, and another part fome time afterwards. I had 

 alfo found that a mixture of dephlogifl:icated and inflam- 

 mable air fufters a confiderable diminution in a courfe of 

 time, though they will not wholly incorporate. But I 

 have lately found that thefe two kinds of air unite com- 

 pletely by being confined fome time together in a moift 

 bladder. 



Having mixed equal quantities of thofe kinds of air, 

 I put them into a bladder, which I left floating in a trough 

 of water, and found, after about a fortnight, that the 

 quantity was confiderably diminiflied ; and examining it, 

 1 found it to be almoft wholly phlogifticated, though 

 there was fomething flightly inflammable in it. On this 

 I put equal meafures (but omitted to note the quantity) of 

 each of the kinds of air into another bladder, and after 

 about three weeks, found it reduced to 12.5 ounce mea- 

 fures, all pure phlogifticated air, without any mixture 

 of fixed or inflammable air that I could perceive. 



I have likewife hit upon another method of forming 

 phlogifticated air by the union of dephlogifticated and 

 inflammable air, viz. by expofing the latter to a furface 

 of rufted iron, which is known to become fo by imbibing 

 pure air. Twenty ounce meafures of inflammable air 



were 



