[ ''SI ] 



By his Lordfliip's mode of diftillation however much feems 

 to be loft during the internal combuftion. I fhould think the 

 Prince of NafTau Saarbrvick's method in this refpedl more advan- 

 tageous. Mr. Sage tells us that by diftillation he obtained from 

 Cannel coal -i- of its weight of tar-j- ; but Mr. Faujas. who ufes 

 Lord Dundonald's method, obtains from the coal of Decife, 

 which feems to be of this kind, only 4 per cent, of tar*. 

 Faujas alfo obferved that this tar is gradually converted into 

 afphalt by long expofure to the air, which confirms the dif- 

 ference I have eftabliflied between the two bitumens. 



Whitehaven Coal. 



Its colour is black. 



Its luftre 3. greafy. Tranfparency o. 



Its fradure plane foliated. Its fragments 2. often difcover- 

 ing quadrangular or cubic diftin<fl concretions, fometimes inter- 

 fered with brownifti red flakes. 



Its hardnefs 6. very brittle. Specific gravity 1,257 by my 

 trials. Stains the fingers, particularly when moift. 



It burns at firft with a clear flame, and for a long time, but 

 at laft cakes. 2+0 grains of it after five hours ftrong heat left 

 only 4 grains of a reddifli aflies, or about 1,7 per cent. 



The 



t 35 Roz. Jour. p. 387. 27 Roz. Jour. d. ;88. 



