jyj, MR. hatchett's observations 



and not loam impregnated with petroleum, as Dr. Milies had 

 fuppofed. I could not then conveniently make a regular 

 analyfis of it, and therefore contented myfelf with briefly 

 defcribing it, in a note annexed to my Paper on bituminous 

 Subftances. * 



Lately, however, my friend John Sheldon, Efq. of Exeter, 

 F. R. S. obligingly fent me feveral pieces of it, together with 

 fpecimens of the different kinds of Bovey coal which have been 

 mentioned ; and thus I was enabled fully to afcertain its real 

 nature and properties. 



/ DESCRIPTION OF THE BITUMEN FROM BOVEY. 



Description of It accompanies the Bovey coal> in the manner already de- 

 from' Bo™/" bribed, and is found in mattes of a moderate fize. 



The colour is pale brownilh ochraceous yellow. 



The fracture is imperfe&Iy conchoidal. 



It appears earthly externally, but, when broken, exhibits a 

 flight degree of vitreous luilre. 



The fragments are irregularly angular, and completely" 

 opaque at the edges. 



It is extremely brittle. 



It does not apparently become foftened, when held for fome 

 time in the hand, but emits a faint refinous odour. 



The fpecific gravity, at temperature 65 Q of Fahrenheit, 

 is, l.l.'jj. 



Some fpecimens have dark fpots, flighlly approaching in co- 

 lour and luilre to aiphaltum ; and fmall portions of the Bovey 

 coal are commonly inlerfpeifed in the larger maifes of this 

 bitumen. 



When placed on a heated iron, it immediately melts, fmokes 

 much, burns with a bright riarae, and yields a very fragrant 

 odour, like fome of the (weet-fcented refins, but which at Jail 

 becomes ilightly tainted with that of afphaltum. 



The melted mafs, when cold, is black, very brittle, 

 and breaks with a glofly fracture. 



EXPERIMENTS. 



Experiments on A. 100 grains of this bitumen, when diftilied until the bulb. 

 f .he fame. Q f ([ ie re tort became red-hot, afforded, 



• Tranfaftions of the Linneaa Society, Vol. IV. p. 139. 



4- i. Water 





