AND OTHER VARIETIES OF COAL. 



109 



the former being from about 18 to 52, the ash from 3"6 to 

 28-5." 



Table of the Proportions of Volatile Matter, of Coke, of Fixed Carbon, 

 and of Ash, in 100 parts of different Coals, and in the Torbane Mineral. 



" The average per-centage of these ingredients in Torbane 

 mineral is 69 of volatile matter, 31 of coke, 12 of fixed car- 

 bon, and 18 of ash. It does not, therefore, differ from coals 

 excepting in two particulars : viz., that it yields more gaseous 

 products and less fixed carbon. But even in these the differ- 

 ence is very trifling ; being only about 2 "4 per cent, more 

 than that of the former from Wemyss' coal, and 8*5 less of 

 the latter than from Methill coal : indeed, some of the samples 

 of Torbane contain only 2 per cent. less. The per-centage of 

 ash in some of the samples is less than in several of the coals ; 

 and the average quantity is not so great as that of Methill 

 and Capledrae." 



