Pd 
Papers relating to the Fusion of Carbon. li 
UH]. Strictures by Ropurt Hare, M. D. Professor of Chemistry, 
&c. &e. upon Professor Vanuxem’s Memoir on Plumbago. 
Anthracite, fused Carbon &c. published in the Journal oj 
the Academy of Natural Sciences, for June 1825, Also a 
Letter from Dr. Hare to Professor SIrtiman, respecting 
some proceeding's of the Academy of Natural Sciences. 
Professor Vanuxem, in a letter to Isaac Lea, Esq. which 
has been lately read before the Academy of Natural Sci- 
ences, endeavours to prove that the fused products obtained 
by Professor Silliman, were none of them carbon ;—first, by 
analyzing anthracite and plumbago ;—and secondly, by ex- 
posing those substances, or mahogany charcoal, severally to 
the compound blowpipe, which he was necessitated to use 
in consequence of not having a Deflagrator. 
The analyses thus given are interesting, so far as they 
may afford correct views of the composition of anthracite 
and plumbago. The only possible bearing which they can 
have on Professor Silliman’s experiments, is in showing 
what every chemist would have anticipated, especially in 
the case of plumbago, that there may be some ferruginous, 
as well as earthy matter, in the minerals in question, and 
consequently that this matter, when exposed to intense heat, 
may be fused into globules. This result is confirmed by the 
actual production of globules from anthracite, and plumbago, 
on due exposure under the compound blowpipe. 
The fusion, however, of some ingredients in a compound 
does not prove the infusibility of others. If another ingre- 
dient, subjected to ignition at the same time, be not fused, it 
may show that it was not to be fused under the circum- 
stances of the experiment in question; but it does not prove 
that under other circumstances it would be insusceptible of 
fusion. 
The flame of the compound blowpipe, necessarily sup- 
ported by oxygen gas, is very unfit for the fusion of char- 
coal, which when exposed to heat and oxygen, passes off in 
the form of carbonous oxide, or carbonic acid gas ;—but the 
opposite is true, of the ignition of the Deflagrator, in pra- 
ducing which oxygen has little or no agency, and with whose 
effects it cannot materially interfere, both on account of the 
excessive rarefaction, and the vapour of carbonaceous matter, 
produced by the extreme heat. 
