I ^54 ] 



for inflammation a higher heat than maltha does, and leaves no 

 coal and fcarce any afhes. 



Oi. this bitumen I found i6i grains requifite to alkalize the 

 fiandard quantity of nitre. It vifibly educed air from the nitre, 

 for there were eruptions from time to time, I fuppofe when the 

 more oily part was confumed and the carbonaceous laid bare ; 

 much of the flame was alfo yellowifh. Hence i6i grains of af- 

 phalt contain only 50 of mere carbon — that is nearly 31 per 

 cent. 



Mr. Thory, burning it in a low heat, found it to leave about 

 i of its weight of coal, after melting, fwellirg and inflamirg as 

 ufual* ; however his afphalt was not perfedlly pure, as he ob- 

 tained fulphur from it. 



Cannel Coal. 



Its colour is black. 



Its luitre common 2. when frefh broken often barely i. Tranf- 

 parency o. 



Its crofs fradure conchoidal. Fragments rather ftiarp. 



Its hardnefs from 7 to 8. Specific gravity by my trials i-,232. 

 Per Doctor Watfon's 1,273. •D'^^s "°^ ^^^^ ^^^ fingers; eafily 



kindles 



» 6 Creli's Chy. Journ. p. 62. 



