upon the Composition of Coal. 



I. II. 



Carbon 83-588 ... 82*960 



Hydrogen 5-150 ... 5-193 



Azote and oxygen 8-743 ... 9*328 



Ashes 2-519 ... 2-519 



100-000 



100-000 



131 



The relation in this specimen is the same as in the former, 

 viz., 1-315C : 1-OOOH or 4 : 3. 



For the sake of convenience and comparison, the following 

 table contains the mean of the various analyses of each speci- 

 men. 



TABLE I. 



TABLE II. 



The first table requires no explanation. The second table 

 contains in the first column, that quantity of oxygen which 100 

 parts of the different coals abstract from the air for perfect 

 combustion. This quantity of oxygen expresses the relative 

 heating power of the different coals, in admitting that the 

 quantity of heat evolved by a combustible substance is pro- 

 portional to the quantity of oxygen which is consumed in its 



K2 



