[ ^S5 ] 



kindles without melting, and burns with a large bright flame, 

 but of fhort duration, leaving a large coaly refiduum ; does not 

 cake. 240 grains of it heated until all the coaly part was con- 

 fumed left 7,5 grains of reddifh brown afhes, moftly argilla- 

 ceous, that is 3,12 per cent. 66.5 grains of it were fufficient to 

 alkalize the ftandard quantity of nitre. It burned with a large 

 bright flame, except the laft portion, which was yellowifh, the pure 

 air of the nitre being then exhaufted. Hence 66,5 grains con- 

 tained 50 of pure carbon and 2,08 of afhes ; then deducing 52,08 

 from 66,5 we find the quantity of bitumen equal 14,42 ; then 

 100 parts of it contain 75,2 of carbon, 21,68 bitumen of the 

 fort called maltha, and 3,1 of afties. 



I TAKE this bitumen to be maltha from its quick inflammabi- 

 lity and the fliort duration and brightnefs of its flame, both which 

 properties indicate the moft inflammable of the bitumens, and 

 whofe flame is leaft durable, from its refufal to cake (caking 

 being a property arifing from the fufion of afphalt) and the diffi- 

 cult combuftibility of the carbonaceous fubftance that remains 

 after the celTation of its flame, qualities that counter-indicate 

 afphalt. 



Slaty Cannd Coal. 



That which I employed was from Ayrfhire in Scotland, the 

 only one of this fort imported to Dublin. 



Its colour is black. 



U 2 Its 



