thl; 



PHILOSOPHICAL MAGAZINE 

 AND JOURNAL. 



30'" SEPTEMBER 1825. 



XXII. Experiments on Anthracite, Plumbago, 8^-c, By 

 Lardner Vanuxem.* 



'T'HESE expei-iments were undertaken with a view to de- 

 -*■ termine whetlier the globules obtained by Professor Silli- 

 man, from the above substances, were owing to a fusion of 

 their carbon, or merely to the impurities or foreign matter 

 contained within themf. They were long delayed by my wait- 

 ing for some sheet zinc necessary to repair a deflagrator in- 

 tended to be used for the purpose of obtaining the globules; 

 but this not arriving, I resolved to avail myself of the sug- 

 gestion of Professor Silliman ; namely, that of using the com- 

 pound blowpipe, which answered perfectly well. In the ex- 

 periments with the blowpipe, the substances were placed upon 

 platina foil, spread upon a lump of magnesia ; the size of the 

 pieces subjected to its action was about half an inch in dia- 

 meter and a quarter of an inch in thickness. The light in 

 the greater number of instances was so intense, that I found 

 it necessary to use double green glasses. 



The mode pursued in the analysis of anthracite and plum- 

 bago was as follows. The presence of water was ascertained 

 by heating a few small pieces of the substance in a glass tube 

 closed at one end ; and the quantity of water, by heating a 

 given portion in a covered platina crucible. Another portion 

 was pulverized in an agate mortar ; then a given weight of 

 it was put into a platina crucible, and kept without its cover 

 at a red heat in a small French furnace until the whole of the 

 carbon was consumed ; the residue was then boiled in water 

 for an alkali; after which operatioN it was heated with caustic 

 potash in a silver crucible : when the fusion of the mass was 

 completed, water was added, and the whole then dissolved 



• PVom the Journal of tlie Academy of Natural Sciences of Philadelphia, 

 for June 182.0. 



t Sec Phil. Mag. vol. Ixiv. p. 4G7; vol. kv. p. 28;J, 



Vol. 66. No. 329. 6V/V. 1825. X with 



