165 



TAB. CLXXXVI. 



BITUMEN resiniferum. 

 Resinous Bitumen. 



Class l. Combustibles. Order 3. Mixed. 

 Gen. 1. Bitumen. 



Syn. Retinasphaltum. Hatchett in Phil. Trans, for 

 1804. 410. 



1 his very inflammable substance would, by its usual ap- 

 pearance, be taken for dark Umber while wet, and for 

 common Clay when dry; consequently there is nothing in 

 its common appearance that would indicate its inflammabi- 

 lity or resinous quality. Very nice discrimination is there- 

 fore requisite to comprehend it. To the touch, however, 

 it in some measure indicates a resinous quality. 



Mr. Hatchett, who first mentioned it in Linn. Trans. 

 v. 4. 139, observes that tf a yellowish brown compact sub- 

 stance, which in colour and fracture somewhat resembles 

 ferruginous clay, is found occasionally with the Bovey 

 Coal. It is brittle, and is highly inflammable; it melts 

 like Bitumen, and emits a smoke which in smell resembles 

 Amber. This substance is but rarely found." He also 

 observes, in the Philosophical Transactions for 1804, p. 402, 

 that " it is found in pieces of a moderate size. The frac- 

 ture is imperfectly conchoidal. It appears earthy externally ; 

 but when broken exhibits, in a slight degree, a vitreous 

 lustre. The fragments are irregularly angular, and com- 

 pletely opaque at the edges. It is extremely brittle. It 



