I 166 3 



geneous matter; it is found in various parts of 

 Europe trickling from the fiffures of rocks. It 

 has a greafy feel, is tranfparent, or femi-tranfpa- 

 rent, of a reddifh or blackifh-brown colour ; by 

 air it becomes like tar, and then is called 



c. Mountain or Mineral Tar, Barbadoes Tar % 

 Bitumen Petroleum tardefluens. It is vifcid ; of 

 a reddifh or blackiih-brown or black ; when burn- 

 ed it emits a difagreeable bituminous fmell, and 

 by expofure to the air, it paffes into 



d. Mountain or Mineral Pitch, Bitumen Mal- 

 tha ; which is more impure than petroleum ; it has 

 the confidence of honey ; is of a brownifh-black 

 colour ; frequently mixed with much earthy mat- 

 ter, refembles common pitch ; when heated emits 

 a ftrong unpleafant odour, like the former fub- 

 fiance ; in cold weather it may be broken, and 

 exhibits internally a glolfy luftre ; when warmed 

 it foftens and pofiefles fome tenacity. It is how- 

 ever fufceptible of a fuperior degree of indura- 

 tion, and then becomes asphaltum. 



e. Asphaltum, or Bitumen of Judea 9 has de- 

 rived it's name from the Dead Sea of Judea, up- 

 on the furface of which it is found, and upon the 

 Chore. It is met with alfo in other countries. It 

 is fmooth, of a black colour, and mining con- 

 ehoidal fra&ure. 



III. COM- 



