Papers relating to the Fusion of Cerbou. 113 
thai 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 Professor 
Silliman. If any evidence be requisite to prove that Pro- 
fessor Silliman never intended to sanction such a procedure, 
it may be found in the following passage, concluding his 
observations on the results obtained by this instrument. He 
says, 
‘‘{ would add that for the mere fusion of plumbago, the 
blowpipe is much preferable to the deflagrator; but a 
variety of interesting phenomena, both in relation to the 
plumbago and the charcoal, are to be exhibited by the lat- 
ter, but not by the former.” 
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 instrament which Professor Vanuxem has 
used for that purpose. 
To conclude: It appears to me that the grounds upon 
which 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 of 
course erroneously treated as an extemporaneous product 
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. 
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, 1 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 pure 
Vou. X:—No. 1. 15 
