f 3 4 A SYSTEM OF 



i. Indurated pale red alum ore, Schiftus 

 aluminis Romanus. Is employed at 

 Lumini, not far from Civita Vecchia 

 in Italy, to make the pale red alum 

 called Roach Alum. This is, of all 

 alum ores, the moil free from iron ; 

 and the reddifli earth which can be 

 precipitated from it, does not (hew the 

 lead marks of any metallic jubilance. 

 c. With a very large quantity of martial 

 clay, which likewife contains an inflam- 

 mable fubftance, Argilla martir.lis et 

 fhlogiftica aciao vitrioli imbata. Common 

 alum ore. 



Is commonly indurated and flaty, and 

 is therefore generally called Alum Slate, 

 Schiftus aluminofus ater et brunefcens. 



It is found, 

 j. Of parallel plates, with a dull fur- 

 face, Schiftus lamellofus regularise from 

 Andrarum in the province of Skone, 

 Hunneberg and Billingen in the pro- 

 vince of Weftergottland, Rodoen in 

 the province of Jemtlarid, and. the 

 ifland of Oeland, &c* 

 2 : Undulated and wedge-like, with a 

 faming furface, ScbisJus aluminofus tin- 

 dulatus ct cumiformis fijfuris fplendcn- 



This at the firft fight refembles pit 

 coal \ it is found in great abundance in 

 ihe parifh of JNas in Jemtland rj*, 



9- In England, the great alum works at Whitby, in York- 

 ftire, are of this kind. £). C. 



\- The purajy above- mentioned {b. i.) of the earth of the 

 Jjosjiaa ux ro^ch ulum, is meant widi the fame reiki cl|yn 



a 



