obtained in the distillation of Wood, ^c. 23 



ratus. The barrels, which were Swedish, were held in a moderate 

 red heat till they burst, when they were instantly withdrawn and 

 cooled in water to prevent the further volatilization of the bitumi- 

 nous matter. As the opening was generally no larger than a pin 

 hole there was no diiEculty in cooling the apparatus in time. In 

 this way, among some failures, I procured a perfect fusion of the jet^ 

 which exhibited the tnie characters of coal, and was taken out with 

 the impression of the irregularities in the barrel. I need not add 

 that in this case the produce had not merely the colour and inflam- 

 mability but the fracture of coal and its odour on burning. It is not 

 unlikely that by a sufficient repetition of these experiments with 

 better regulated heats and more leisure than I possessed, several 

 varieties of coal might have been in this way produced. Indeed 

 some of the specimens exhibited a dry, and others a fat appearance, 

 but it was impossible in general to detach them from the barrels 

 without reducing them to small fragments. Two other circum- 

 stances occurred deserving; of notice. In one or two cases where 

 the heat had been too great, a portion of the jet was reduced to 

 charcoal, which continued attached to the coaly matter, and the clay 

 was in every instance blackened to a considerable distance from the 

 jet, and converted into a hard compact substance resembling bitu- 

 minous shale in its smell and consistence. 



Reverting to the chemical nature of the other lignites, there is 

 very little reason to doubt that those among them which approach 

 the nearest to a slate of perfect bituminization, would have given- 

 results nearly similar, but I could not pursue the investigation for 

 want of sufficient specimens. From peat we should expect but a 

 mixed matter, varying between the bitumen of wood and true 

 bitumen, according to the degree of change previously undergone ; 

 for that the process of bituminization is the effect of water, and not 



