﻿1848. TERTIARY COAL FORMATION. 187 



in the same latitude. Specimens of this coal 

 examined by Mr. Bowerbank Avere pronounced by 

 him to be decidedly of coniferous origin, and the 

 structure of the wood to be more like that of 

 Pinus than Araucaina ; but on this latter point he 

 was not so certain. It is probable that the exami- 

 nation of a greater variety of specimens would 

 detect several kinds of wood in the coal, as a bed 

 of fossil leaves connected with the formation reveals 

 the existence at the time of various dicotyledonous 

 trees, probably Acerinece, and of one which I am 

 inclined to consider as belonging to the yew tribe. 

 To these I shall refer again. 



When exposed for even a short time to the 

 atmosphere, the coal splits into rhomboidal frag- 

 ments, which again separate into thin layers, so 

 that it is difficult to preserve a piece large enough 

 to show the woody structure in perfection. Much 

 of it falls eventually into a coarse powder ; and if 

 exposed to the action of moist air in the mass it 

 takes fire, and burns with a fetid smell, and little 

 smoke or flame, leaving a brownish-red ash, not 

 one tenth of the original bulk of coal taken from 

 the purer beds, for some contain much more earthy 

 matter. 



Different beds, and even different parts of the 

 same bed, when traced to the distance of a few 

 hundred yards, present examples of " fibrous brown 



