Fusion of Charcoal. 363 



tliat the fused substance is nothing else than carbon in an 

 extremely condensed state; with a specific gravity superior 

 to that of the Anthracite, equal to that of the heaviest 

 Plumbago, and in some degree approximating towards that 

 of the diamond. 



The experiment upon which this conclusion was founded, 

 was as follows. Several pieces of the fused charcoal were 

 placed on a small fragment of brick; this was floated in a 

 dish of mercury, and the whole was covered with a small 

 bell glass filled with oxygen gas, obtained over mercury, 

 A burning lens of one foot in diameter and eighteen inches 

 focus, at noon, with a bright sky, (Aug. 29) was made to 

 throw the concentrated rays of the sun, upon the melted 

 charcoal. There was no appearance of combustion, that 

 could be distinguished by the eye, in the bright light of the 

 focus, but, the sul^tance wasted very slowly away, and 

 at length disappeared leaving no residuum. The gas, exami- 

 ned in the usual way, gave carbonic acid, mixed with an 

 excess of oxygen gas, which, after the carbonic acid was 

 removed, sustained combustion as it usually does when 

 pure. The heat of the lens had been so intense as to fuse 

 and vitrify the surface of the brick support. 



Strong sulphuric acid boiled upon the fused charcoal 

 produces no effect, while with the common charcoal 

 (as it is well known) it is decomposed. The strongest 

 nitric acid in the cold does not affect the melted substance, 

 and even with the aid of a boiling heat, the effect is only 

 slight, and ceases immediately when the heat is withdrawn. 

 The most interesting of these experiments have been re- 

 peated in the presence of Bishop Brownell,* and of Pro- 

 fessor Griscom who were well satisfied with the results. 



Many specimens of the melted charcoal have been sub- 

 mitted to the inspection of Dr. Hare, who is of opinion 

 that they have undergone a true fusion. This gentleman 

 has also so far repeated the experiments mentioned in the 

 former communication, as to be entirely satisfied of their 

 correctness. 



* Formerly Professor of Chemistry in Union Colleo;e, Schenectady. 



Vol. V....No. II. 47 



