Mr. Hatchett'j Ohfervatiom on Bituminous Sub/iances. 149 



tranfparent, and of a yellowilh brown inclining to orange. It it 

 fofr, very elaftic, and (when recently cut) adheres to the fingers, 



A, No. 10. 

 The fame of a darker brown, and harder in a fmall degree. The 

 fpecifk gravity of this fpecirnen is 0,9053; water being eftimated 

 at 10,000 at temp. 6o°. 



A, No. 11. 



Bitumen of a dark brown, harder than the former. This ex- 

 actly refembles the cahout-chou in the degree of elasticity, and in- 

 the property which it poflelTes of removing the traces of black- 

 lead. 



A, No. 12. 



The fame, but rather harder* 



A, No. 13. 



The fame of a bladufh brown, which is flightly elaftic when the 

 weather is warm, but is brittle when cold. 



A, No. 14. 



The fame of a blackifti brown, nearly black, which fcarcely pof- 

 feffes any elafticity ; it breaks, and refembles afphaltum in luftre, 

 colour and fra&ure. 



A, No. 15. 

 The fame of a reddifh brown, perfectly hard and brittle. The 

 characters of afphaltum are complete in this fpecirnen. 

 The fpecific gravity is 10,233, 



The other fpecies of elaftic bitumen, which I fball diftinguiih by 



the 



