C nt 3 



magnefia 38. Silex 47. Carbonate of lime 2. 

 Argill 4. Oxyde of iron 9. Hoepfner. 



o. Baikalite, cryftallized in tetrahedral prifms, 

 entire or truncated, with oblique brifmsf and in 

 bexahedral prifms. Anal. Magnefia 30. Silex 

 44. Lime 20* Oxyde of iron 6. Lowitz. V 



p. Boracite, found only in the mountain of 

 Kalkberg, near Luneburg; colour greyifh white t 

 inclining to purplrfh ; cryftallized in cubes, with 

 truncated edges and angles ; does not effervefce a 

 or diffolve in acids, unlefs heat be applied. Anal n 

 Boracic acid 68. Magnefia 13. Lime 11. Si-, 

 lex i, Argill 1, Iron 1. Westrumb. 



E. ARGILLy or Alumine, aluminous, or argil- 

 laceous earth ; the earth contained in fulphate of 

 alumine, or common alum, has notafte, and is in- 

 foluble, hardens in the fire, although divifible in 

 water, contracting in it's dimenfions, and when 

 expofed to an extreme heat, becomes fo hard as 

 to ftrike fire with fteel. 



a. Sulphate of Alumine y or alum, is an earthy 

 fait, which confifts of the fulphuric acid and alu- 

 mine* 



b. Carbonate of Argill, Lac lunae. Colour pure \ 

 white, found in nefts, in compacted, rounded, kid- 

 Bey-form maffes. Confifts of carbonic acid, ar-, 

 gill and fome lime* Sckreiber. 



c. Clarjy Pipe Clay % white, very little greafy to 



the 



