4o3 Dr. priestley’s Experiments relating to Phlogifton , 
A quantity of manganefe abforbed 7 ounce mealures of in- 
flammable air ; but I could not perceive any thing in it which 
had the appearance of metal. But I imagined 1 had not heat 
enough for the purpofe, and mixing with it home calcined bo- 
rax, 1 repeated the experiment, when there was again an evi- 
dent abforbtion of air, and in the courfe of that experiment, I 
once thought that 1 did perceive a lmall globule of metal. 
Zinc and arfenic were only fublimed in this procefs. The 
fame was the cafe with the glafs of antimony ; but the experi- 
ment was attended with this peculiar circumflance, that when 
the glafs was melted in inflammable air it formed itfelf into 
needle-like cryftals arranged in a very curious manner, though 
I could not produce that appearance in other kinds of air. 
Inflammable air being clearly imbibed by the calces of me- 
tals, and thereby reviving them, is a fufficient proof of its 
containing what has been called phlogifton ; and its being ab- 
forbed by them in toto , without decompofltion, is a proof of its 
being nothing betides phlogifton in the form of air , unlefs there 
fhould be fomething lolid depofited from it at the fame time 
that the proper phlogiflic part of it was abforbed. With re- 
fpefl to this, I can only lay that, in the courfe of the experi- 
ments, I did not perceive any thing of the kind : for though 
in lome of the procefles there was a black Imoke produced, in 
others I could perceive nothing but part of the calx fubliming, 
and clouding the glafs. On this account, however, I could 
not pretend to alcertain the weight of the inflammable air in 
the calx, fo as to prove that it had acquired an addition of 
weight by being metallized, which 1 often attempted. But 
were it pofhble to procure a perfect calx, no part of which 
fhould be fublimed and difperfed, by the heat neceflhrilv to be 
made ufe of in the procefs, I fhould not doubt but that the 
quantity 
