C "4 ] 



flightly ; foftens eafily in water, but is not fit for 

 pottery ; feels greafy ; acquires a polifh by light 

 fri&ion; of different colours, the red called Ar- 

 menian bole, ufed for red pencils. The Terra 

 Lemma, which belongs to this tribe, contains filex, 

 argill, magnefia, calcareous earth, iron and water. 

 The indurated bole, or red chalk, is hard and 

 brittle, and intimately united with oxyde of iron. 

 Anal. Argill 19. .Silex 47. Carbonate of lime 

 5,4. Carbonate of magneiia 6. Oxyde of iron 

 5,4. Water and air 17. Bergman, 



h. Tripoli, fo called from the place whence it 

 was firft brought to us ; colour whitifh, grey or 

 ochre yellow ; is found folid ; has a dull and ear- 

 thy appearance when broken ; is foft and fandy 

 between the teeth ; abforbs water with a noife, 

 during which air bubbles are expelled; does not 

 effervefce with acids, unlefs mixed with marl, 

 which it often is. Anal. Argill 7. Silex 90. 

 Iron 3. Hasse. 



i. Lepidolite, amorphous, foliated. Anal. 

 Argill 38,25. Silex 54,5. Oxyde of iron and 

 manganefe 0,075. Water and air 2,5. Klapr. 

 Silex 54. Alumine 20. Fluate of lime 4. Oxyde 

 of manganefe 3. Oxyde of iron 1, Potafh 18. 

 Vauauelin. Lelievre. 



k. Sappare, Cyanite, compofed of long laminae; 

 white, with {hades of fky or PrufTian blue; luftre 

 like mother of pearl; it is rather brittle, femi- 

 tranfparent, foft, and can be fcraped with a knife; 

 feels to the touch like talc. Anal. Argill 67. 



Silex 



