Papers relatung to the Kusion of Carbon. 1g 
that already published by him, [see Vol. VIII. p. 292, and p. 
102 of the present Vol. of this Journal,] much more than it 
disproves any of the allegations of Professor Silliman. 
Mr. Vanuxem justifies himself for resorting to the com- 
pound blowpipe, in order to invalidate results obtained by 
an instrument extremely different in its character, by saying 
that he has done so in obedience to a suggestion of tetas 
Silliman. If any evidence be requisite to prove that Pro- 
fessor Silliman never intended to sanction such a procedure, 
itmay be found in the following passage, concluding his 
_ Observations on the results obtained by this instrument. He 
says, - —- 
_“*L would add that for the mere fusion of plumbago, the 
blowpipe is much preferable to the deflagrator; but a 
variety of interesting | ena, in relation to t 
plumbago and the fo con are to be exhibited by the lat- 
ter, but not by the former.’ es eat 2 t 
__ In another place he observes, ‘* Were the diamond a good 
conductor, it would be melted by the deflagrator ; and were 
it incombustible, a globule would be obtained by the com- 
pound blowpipe.” | 
It is evidently therefore the opinion of the author of this 
passage, that carbon, even in its most incombustible state, 
as in that of the diamond, is still too combustible to yield 
globules with the instrument which Professor Vanuxem has 
used forthat purpose. ss * Sis 
To conclude: It appears to me that the grounds upo 
whieh the results of Professor Silliman have been assailed by 
Mr. Vanuxem, are utterly untenable. The animadversions 
of his first memoir were founded on an analysis of a globule, 
which being proved by himself to be malleable iron, was o 
course erroneously treated as an extemporaneous produt 
from a minute portion of wood charcoal. In the memoir 
now under consideration, he adduces experiments performed 
by the compound blowpipe, in order to invalidate observa- 
tions made by means of an instrument of a very different 
character. __ : é ‘ 
_ So far as respects the curious and interesting phenomenon 
of a projection arising on the charcoal attached to the nega 
tive pole of the deflagrator, | am fully prepared to bear 
witness to the correctness of the description given by Pro- 
fessor Silliman, There has been no conclusive analytic 
demonstration that the excrescence which thus arises is pare 
Vor. X:--No. 1. Np 
