192 



FORMATION OF COAL. 



J^rmatiou of €0al 



BY E. WETHERED, F.G.S., F.C.S. 



Head Novemler \st, 1877. 



CHEMICAL analysis shows that the combustible portion of 

 coal consists of Carbon, Hydrogen, Oxygen, Salphur, and 

 a little Nitrogen, which with the ash make up the total composition. 

 In the following table the partial analysis of several kinds of 

 coal is given, with that of wood : it is copied from Roscoe and 

 Schorlemmer's chemistry. 



On referring to this table we observe that wood contains the 

 same constituents as the coal ; but as we descend towards 

 Anthracite, we find that the proportion of Carbon increases, -vvhile 

 the other constituents decrease. As we look down the table we 



