132 GEOLOGICAL RECONNOISSANCE 



From the insight obtained into the chemical composition of this coal, by 

 an approximate chemical analysis, I am 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 fixed 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. Lyhens valley. 



Volatile combustible matter, 7.9 6.88 



Fixed carbon, 85 - 6 83 - 84 



Ashes, 6.0 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. 



