December, 1842.] 223 



Selenite, Bbrous and lamellar, Blomidon. 

 Pebbles, from Bay Chaleur. 



DONATIONS TO LIBRARY. 



Voyages en Scandinavie, en Laponie, &c. &c. Par M. Elie 

 tie Beaumont. From the Author. 



VERBAL COMMUNICATIONS. ' 



Prof. Johnson mentioned that he had made trials to'determine the vola- 

 tile and earthy ingredients of the so-called natural coke from Virginia, of 

 which samples were exhibited at a preceding meeting of the Academy. 

 This substance presents in its exterior appearance a strong contrast with 

 all known varieties of either anthracite or bituminous coal. It is wholly 

 wanting in lustre. It has lost, if it ever possessed, all continuous slines or 

 cleats, and even the surfaces of deposition appear to be in a great degree 

 obliterated. Its texture is porous. It is in very many, if not in all speci- 

 mens, strongly charged with iron pyrites, which, by exposure to the air, 

 efflorescing into sulphate of iron, gives the appearance of friability to the 

 material, and by this means distinguishing it clearly from anthracite. 



Two samples of this combustible were tried for the purpose of ascer- 

 taining the amount of earthy matter, volatile matter, and fixed carbon. 



The first gave of 



per cent. 



Volatile matter, 11 16 



Carbon, 77.86 



Earthy matter, 10.98 



100. 



The second, which appeared to be rather more highly charged with py- 

 rites than the other, gave, by the mean of four separate incinerations, of 



100. 



The distillation of this fuel by the immediate application of a red heat, 

 produces a gas which burns with a steady clear flame, of a yellowish white 

 color, accompanied by a little smoke, which, however, nearly or quite dis- 

 appears when the access of air is free and abundant. 



The distillation produces no enlargement of volume or adhesiveness of 

 the particles of carbonaceous matter, as in certain serai- bituminous or 

 " transition" coals, such as that found on Stony Creek, iu Dauphin county, 

 Pennsylvania. 



Iu regard to the applicability of the term " natural coke" to this sub- 

 stance, Prof. J. remarked, that understanding this term as indicating a 

 change of texture from that of the bituminous coal of the same district, a 

 partial discharge of the volatile ingredients of the same coal, and as a 



32 



