214 THE ACTION OF ORGANIC SULPHUR IN COAL. McCALLUM. 



The proximate analyses of these samples are as follows : 



TABLE I. 



The only method at present available for the determination 

 of the organic sulphur in coal is by difference, and there is one 

 inherent source of error which, however, I think is not material. 

 The method referred to is as follows : The percentage of iron 

 is determined. Then this iron is combined with the necessary 

 amount of sulphur to form iron pyrites (Fe S 2 ). This amount 

 of sulphur is deducted from the total amount in the coal and 

 the balance is called organic sulphur. 



The error referred to in this method is due to the fact that 

 it is almost certain that there is some iron present as silicate 

 in the " stone and shale" which are always present in, the coal. 

 But as the percentage of iron in the " stone and shale " rarely 

 exceeds 3 per cent, and the percentage of stone and shale in the 

 coal under consideration rarely exceeds 5 per cent, of the coal 

 by weight, it will readily be seen that any error introduced will 

 be exceedingly small. 



Applying this method to the samples under consideration, 

 we obtain the figures given in Table II. 



TABLE II. 



No, Organic sulphur. Inorganic sulphur. 



1 37.86% 62.14%. 



2 56.59% 43.41% 



3 71.56% 28.44% 



i 83.16% 16.84% 



5 85.23% 14.77% 



