290 Dr. Priestley's 'Experiments and Obfervations 
they had been ufed to do, arid continued to do fo many hours £ 
1 even got ten ounce meafures of inflammable air from two 
ounces of iron filings in a coated glafs retort. At length, how- 
ever, the production of inflammable air from the gun -barrel 
ceafed ; but on putting water into it, the air was produced 
again, and a few repetitions of the experiment fully fatisfied 
me that I had been too precipitate in concluding that inflam- 
mable air is pure phlogihon. 
I then repeated the experiment with the charcoal, making 
the receiver, the Hand on which I placed the charcoal, and the 
charcoal itfelf, as dry and' as hot as poflible,, and ufing cement 
mile ad of a wet leather to exclude the air. In thefe circum- 
hances 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 moihure as was depofited from the air in its 
hate of rarefaction, and before it could be drawn from the 
receiver. To the production of this kind of inflammable air I 
was therefore now convinced, that water is as neceiihy as to 
that from iron. 
It was in this hate of my experiments that I received an, au- 
thentic account of thole of M. Lavoisier, on tranfmitting water 
through an hot iron tube and alfo through a hot copper tube 
containing charcoal, 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 fubjeCl. I had 
heard an account of the experiments fome months before; but 
k was fo imperfeCt a one, that I own I paid little attention to 
them. At this time, however, I was prepared to be fufficiently 
feniible of their value,,. 
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