132 GEOLOGICAL RECONNOISSANCE 
From the insight obtained into the chemical composition of this coal, by 
an approximate chemical analysis, Iam led to believe that the valuable 
properties of this coal have hitherto been overlooked. 
The experiments of Johnson, De la Beche, Playfair, Hayes and Rogers, 
on different coals, as well as the experience in the East, go to prove that, 
though the semi-anthracites may not be the best adapted for some pur- 
poses, they have far higher heating and considerably more. reducing powers 
than the best bituminous coals; and, besides, the semi-anthracites will 
evaporate, in a given time, from 15 to 20 per cent. more pounds of water 
than bituminous coals. It has been shown, moreover, by Hayes and 
Rogers, that the efficiency of the semi-anthracites in these operations is 
due to the total amount of carbon that enters into the composition of 
both coke and volatile combustible matter, but principally to the amount 
of fized carbon to be found in the coke alone; for it appears that the 
volatile carbon, i. e. the carbon which escapes as gas in the form of 
carburetted hydrogen, contributes but little to the actual heating effect, 
since the greater part of the caloric, generated by the combustion of this 
gas, becomes latent or absorbed by its change of state, from the solid or 
condensed condition in which it exists in the coal, into the elastic gaseous 
form it assumes during combustion. 
Now, the analysis of the Spadra coal proves it to contain 25 to 30 per 
cent. more fixed carbon in the coke than the best bituminous coals* of 
Europe or America; and it even exceeds, by 1.35 per cent. that of the 
richest semi-anthracites of Pennsylvania; it has 3.83 per cent. more fixed 
carbon in the coke than the celebrated “Parker vein,” of George creek 
valley, Maryland. 
Of the forty-three coals reported on by Johnson, in his work on Ameri- 
can coals, the semi-anthracite of Lyken’s valley approaches nearest in 
composition to the Spadra coal, as will be seen by comparing the following 
approximate analyses of these two coals: 
Spadra. Lyken’s valley. 
Volatile combustible matter,. . . . . . 7.9. 6.88 
Fived carbom,. . © .« «. » « « » « «= 8.6 83.84 
ABHOR, 2 « ww Rw ww a ae ew ce OD 9.25 
The composition of the Spadra coal approaches so nearly to that of the 
Lyken’s valley coal of Pennsylvania, that we may assume the practical 
* A sample of Pittsburg coal, analyzed by Johnson, gave 54,93 fixed carbon. <A specimen, 
analyzed by Dr. Robert Peter, 65.30 fixed carbon in coke. A specimen of Youghiogheny ‘coal, 
analyzed by myself, gave 60.14 fixed carbon in coke. Johnson’s specimen must have been an 
inferior specimen, for the best Pittsburg coals always give a larger per centage of fixed carbon in 
the coke than 54,93. 
