EARTHS. ARGILLACEOUS. 35.Ardefia. 125 



4, Kolon, Cronst. mineral, /eft. 158. 



Found in Britain^ S^veiieth and Lusatia^ forming large beds in 

 itracified mountains, and is ftrongly Impregnated wiih bitu- 

 men and fulphur pyrites: colour generally black, a little 

 glittering when broken: when expofed to heat it fm^-kes or 

 flames, emits a bituminous odour, and becomes pakr uitcr 

 loli:,g its bitumen. 



Kellas. Of a fibrous texture, lligbtly adhering to the tongue. 



Killas. Kiriuan nii-'^eral. \ p. 237, 



Found in Corn^ivall, of a pale blucilh-grey, red, or whitifh- 

 yellow coiour, and often interfered with veins of copper or 

 tin: furface undulated : fr:i(f:"ture long, fplintcry, imperfedly 

 llaty : Jullre opake, filky : co itains filica c,6o: argil 0,25. 

 magnclia 0^09 iron 0,06, and foir.e petrol or birumen. 

 Kir^ivan, 



Nigfica, Deep black, meagre, very foft, foiling the fingers, making 

 a black ftreak, of an incurved llatv texture, breakin;i- 

 into difcoid fragments or long fplinters, becoming 

 reddilh-grey in the fire. 



Schiflus fcriptura atra. Ss'fi. nat. xii. 3. p. 3S. n. g. 



Schillus mollis niger. Wall. fyst. i. />. 343. ».8. 



Black cha'k. Kirivan mtneral. \.p 195. 



Black chalk, SchmeilJer ntmer. \. p. 173. Thomf, 3. /. 538. 



Found in Westrogoth, FrancGmcif and Italyiy in folid mafTes, 

 without lultre: adheres flightly to the tongue, feels fmooth, 

 afllimes a polifh from a knife, gives a bl?xk llreak and marks 

 black, does not readily moulder in water, or eiTervefce or dif- 

 folve in acids, when heated torednefs becomes reddiih-grey : 

 contains filica 64,60. alu^Tiina 11,25. charcoal 11,00. 'ox)de 

 of iron 2,75. water 7,50. Weigleb. 



tessuJaris. Very foft, fomewhat ponderous, breaking into trapezoid 

 fragments, of a llaty texture. 



Schiftus rhombeus. Gerh. Bsytr. mh. i. p. 343. n. 5. 



Found in Silefta near Goldberg and Neiidcrf^ forming entire 

 mountains, of a brown, pale yellow, or green colour. 



