290 T)r, FRiEsrLEY''s: Expen'me?2l5 and Objervailons 

 they had been ufed to do, and conthined to do fo many hours ■;-. 

 1 even got ten ounce meafures of intlammable air from two^ 

 ounces of iron filings in a coated glafs rttort. At length, how- 

 ever, the produ6tion of inflammable air from the gun-barrel' 

 ceafed ; but on putting water into i'c, the air was produced^ 

 again, and a few repetitions of the experiment fully fatisfied' 

 3ie that r had been too precipitate in concluding th-at inflam- 

 mable air is pure phlogiilon. 



I then repeated the experiment with the charcoal, making- 

 the receiver, the fland on w^iich I placed the charcoal^ and the- 

 charcoal itfelf,, as dry and as hot as poffible, and ufing cement 

 inftead of a wet leather to exclude the air. In thefe circum- 

 ifances I was not able, with the advantage of a good fun, and- 

 an excellent burning lens, to decompofe quite fo much as two^" 

 grains of the piece of charcoal, which gave me ten ounce mea- 

 fures of inflammable air; and this, I imagine, was effected by 

 means of fo much moifture as was depofited from the air in its 

 fl:ate of rarefaction, and before it could be drawn from the 

 receiver. To the production of this kind of inflammable air I 

 was therefore now convincedj that? water is as necellkry as to 

 that' from iron. 



It was in this frate of my experiments that I received an au- 

 thentic account of thofe of M. Lavojsier, on tranfmitting water 

 through an hot iron tube and alfo through a hot copper tube- 

 containing charcoalj and thereby procuring large quantities of 

 inflammable air, M. Lavoisier himfelf having been fo obliging^ 

 as to fend me a copy of his Memoir on that fubjeft. I had 

 heard an account of the experiments Ibme months before; but* 

 it was fo imperfeCl a one, that I own I paid little attention to 

 them. At this time, however, I was prepared to be fufficiently 

 fenfible of their value. 



In 



