196 E. B. Andrews on a Seam of Coal. 
The coal was analyzed by Dr. J. S. Newberry and gave: 
Volatile matter, 49 to 51 per cent. 
Fixed carbon, $F 467% 6 2% 
A h eee Fors “ 
edimentary matter. In the fracture these layers present the 
‘abe ante of parting with remarkable readiness with its gas oF 
ydro-carbons, for the coal is very rich in gas and burns with 
remarkable freedom. In the grate it differs from the Wheeling 
eoal, as dry wood differs from wet green wood. Why the 
presence of these lamin of sedimentary matter—thinner than 
any tissue paper—should thus facilitate the production of gas, 4 
fact which I have observed in some cannel coals, has not been 
explained so far as I know. Besides these peculiar laminations, 
there are the usual ones, which most geologists regard as pro- 
duced by the different increments of vegetable matter, and show- 
ing perhaps periodicity in the growth and falling of the leaves 
and fronds of the coal vegetation. The Pittsburg coal exhibits 
this class of laminations in smooth and highly polished horizon- 
tal surfaces, and it is by these that this coal is readily distin 
guished from other Western coals, In the Bear Creek coal we 
find also laminx of mineral charcoal. This is sometimes found 
in plates one-fourth of an inch in thickness, It exhibits a fibrous, 
woody structure, and is very soft and easily reduced to powder. 
Whether this charcoal is produced by some peculiar property 10 
h did not permit the usual 
of sugar cane, it is perhaps impossible to determine. The first 
class of laminz, those having a sedimentary appearance, doubt- 
less tells a tale of water, and indicates that the vegetation grew 
where it was very marshy and constantly inundated. This water, 
however, contained only the slightest possible amount of impal- 
pable sediment, and eould scarcely have been much discolored. 
‘his marshy charaeter of the coal field and the overflow of 
‘water doubtless-caused an unusual softening and maceration of 
he fallen vegetable matter, and produced the cannel-like char- 
___ aeter of the coal. But while the coal marsh was ordinarily more 
or less covered with comparatively pure water, at one time ib 
