112 Papers relating to ihe Fusion of Carbou. 
The fusion of plumbago by the former was readily effected 
by me more than twenty years ago, as may be seen in my 
memoir on the supply and application of the blowpipe. 
The same resuit was sibsequently accomplished by Pro- 
fessor Silliman, and now, agreeably to the memoir before us. 
by Professor Vanuxem himself. According to the analysis 
mentioned in this memoir, in which plumbago, is thus admit- 
ted to be fusible, it differs from carbon only in containing 
three parts in a hundred of iron. Upon what ground then 
has Professor Vanuxem been so mcredulous, respecting the 
fusibility of carbon, as to believe more readily that Dr. 
Macneven had obtained from it a globule of iron, than that 
Professor Silliman could accomplish its fusion ? 
Dr. Hays stated, before the Academy of Natural Sciences, 
at their last meeting in March, that at the time of sending 
to Judge Cooper the globule analyzed by Mr. Vanuxem, 
it was represented as a product of mahogany charcoal.* 
Professor Vanuxem has not as yet acknowledged himself, or 
Dr. Macneven, to have fallen into any error in treating 
malleable iron as a possible extemporanecous product of 
mahogany. He has not even done me the honour of 
noticing the paper in which it was demenstrated that tm so 
treating it he had made a mistake. We are of course to 
infer that he still adheres to the position that wood charcoal 
may yield, during a transient exposure to ignition, a globule 
of iron in its metallic form. Uader these circumstances, it 
must surprise every reader, that he does not by an analysis of 
mahogany charcoal, endeavour to prove that iron exists in it 
in such quantity, as that such a ferruginous globule may be 
in such manner obtained from it. If the negative proof 
founded on his neglect to analyze this substance, on which 
the observations of Professor Silliman were chiefly made, be 
combined with tie positive evidence furaished by iis own 
analysis, that even in plumbago, which is considered as a 
carburet of iron, this metal does not exist in quantity ade- 
quate to have produced a globule principally ferruginous, 
during a momentary ignition, it seems to me that the late 
memoir of Professor Vanuxem tends to prove the fallacy of 
* Professor Macneven has recently stated the same fact, in canversa- 
fton with the editor, September 1825. 
