Chemical Examination of Bituminous Coal. 369 



Art. XIX. — Chemical examination of Bituminous Coal from 

 the pits of the Mid Lothian Coal Mining Company, south 

 side of James River, fourteen miles from Richmond, Vir- 

 ginia, in Chesterfield Count]/; by B. Silliman, Professor of 

 Chemistry, &c. in Yale College, and O. P. Hubbard, Professor 

 of Chemistry, &c. in Dartmouth College. 



Three specimens of fair average quality, not selected for any 

 apparent superiority, were taken from a hogshead of the coal, 

 sent by the President of the company, A. S. Wooldridge, Esq., 

 and experiments were made upon portions of these samples indis- 

 criminately taken. 



Physical Characters. — The coal is in the fresh fractured sur- 

 face of a jet black color ; lustre, resinous and splendent ; fracture, 

 slightly conchoidal ; sphts easily, parallel to surfaces of deposition 

 which are strongly marked ; the two sets of slines considerably 

 distinct in large masses and in small specimens very distinct, 

 showing a rhombic structure, in several specimens before us, 

 making with each other angles of 78° and 102°. 



There is another series of faces, very lustrous and splendent, 

 that also intersect at angles of 78° and 102°. These two series 

 of faces cross each other and the surfaces of deposition, and give 

 rise to two rhombohedra that incline in opposite directions. By 

 these the coal is intersected so frequently as to divide it into lay- 

 ers of a line in thickness in one direction. The coal is compact, 

 and the specific gravity of three samples taken as above, was 



A. 1.281 



B. 1.312 



C. 1.284 



3.877^3 = 1.292. Sp. gr. water being 1. 

 No. 1. Sixty three and a half grains were coked for two and 

 a half hours, in an iron bottle in a draft furnace, and the gaseous 

 products were collected dry over mercury. 



a. All the jars of gas, eighteen in number, were examined by 

 caustic potassa ; the carbonic acid was thus absorbed, and was 

 equal to 80 cubic inches, or 1600 parts, being two fifth parts of 

 the volume of the gas. 



b. Binoxide of nitrogen gave in jar 1, a slight redness, thus in- 

 dicating oxygen gas. 



Vol. xLn, No. 2.— Jan. -March, 1842. 47 



