636 



Proceedings of the Royal Irish Academy. 



In the coal from the basin of Maryland, bordering on Pennsylvania^ 

 a similar result was obtained. The coals are bituminous. 



Maryland Coal Basin, 





Mean Sp. Gravity. 

 Two Specimens. 



Mean amount Ash 

 Two Specimens. 



1 



2 

 3 

 4 

 5 



1-320 

 1-350 

 1-360 

 1-385 

 1-485 



7-52 



9-58 



10-35 



11-75 



14-41 



My analyses show a very close agreement in this respect "with some 

 of the Maryland coals, as will be seen from the following Table : — 



Dttngankon Coal-Field. 







Specific Gravit)'. 



Amount of Ash. 



1 



2 

 3 

 4 

 5 



Annagher coal, . . . 

 Beltiboy „ ... 

 Gortnaskea coal, cannel, 

 Lurgaboy top coal, . . 

 Do. bottom coal, . 



1-250 

 1-266 

 1-232 

 1-295 

 1-385 



1-92 

 2-43 

 4-06 

 4-57 

 11-28 



6 



Creenagb coal, cannel. 



1-386 



12-95 



7 



Do. soft coal, . . 



1-452 



16-80 



8 



Derry coal, .... 



1-499 



18-00 



"With the exception of the Gortnaskea cannel, which slightly 

 breaks the series, this increase of ash with that of the specific gravity 

 is extremely well marked here. Some of these, compared with those 

 determined by Professor Johnson, exhibit an agreement that is very 

 striking indeed. It is useless comparing the anthracite coals, for, 

 as I have already remarked, the specific gravity is always higher, 

 ecRteris paribus ; but I have given below some other analysis of bitu- 

 minous coals, and they agree fairly well in the relation between the 

 specific gravity and the amount of ash. 



Belleville Distkict, Illinois.* 





Specific Gravity. 



Ash. 



1 



2 

 3 

 4 



1-293 

 1-296 

 1-315 

 1-340 



4-50 to 5-40 



8-60 



8-90 



13-01 



* Coal Eegions of America. J. Macfarlane, M.A., p. 425. 



