464 On phlogiston, 



fares of the Inflammable air will difappear, and the remain- 

 ing four ounce meafures, will not be diminiflied by the teft 

 of nitrous air. 



When the proportion of precipitate is large, and the in- 

 flammable air Imall, after the inflammable air difappears, 

 the precipitate will give out its oxygen, and the air which 

 remains, will be diminiflied by the tefl of nitrous air. 



This circumftance has happened in fome of the experi- 

 ments of Dr. Prieftley. 



Another objedlion brought forward by Dr. Prieftley is, 

 that if hydrogen be nothing more than a component part of 

 w^ater, it never would be produced, but in circumftances 

 in which either water itfelf, or fomething into which wa- 

 ter is known to enter is prefent. He tells us, that upon 

 heating finery cinder together with charcoal, inflammable 

 air is produced, though according to the new theory no 

 water is concerned. 



The antiphlogiftic chemifts never faid, that hydrogenous 

 gas could not be produced without water ; for it is a confti- 

 tuent part of other bodies, as alcohol and ammoniac. 



To afcertain the quantity of hydrogenous gas, afforded, 

 by charcoal and finery cinder expofed to a high degree of 

 heat, an ounce of the fcales of iron and the fame quantity of 

 charcoal, both reduced to a very fine powder, were fe- 

 parately expofed in covered crucibles, in an air furnace, well 

 fupplied with fuel, for five hours. They were then taken 

 out of the fire, and mixed while red hot in a red hot iron 

 mortar, were triturated with a n'^ y6o/ peftle, formed of an 

 iron ramrod, were poured upon a red hot piece of flieet iron, 

 and inftantly put into a red hot gun barrel which was fixed 

 in one of Lewis's black lead furnaces, and which commu- 

 nicated with the worm of a refrigeratory, a part of a hy- 

 dropneumatic apparatus. Immediately after luting one 

 end of the gun barrel to the worm, one hundred and forty- 

 two 



