A SYSTEM OF 
i . Indurated pale red alum ore, Schiftus 
aluminis KompMUs, 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 moft free from iron ; 
and the reddilh earth which can be 
precipitated from it, does not fhew the 
lead marks of any metallic fubftance. 
With a very large quantity of martial 
clay, which likewife contains an inflam- 
mable fubftance, Argilla martialis et 
fhlogiftica acido vitrioli imbuta. Common 
alum ore. 
Is commonly indurated and flaty, and 
is therefore generally called Alum Slate^ 
Schiftus aluminojiis ater et brunefcens. 
It is found, 
1 . Of parallel plates, with a dull fur- 
face, Schiftiis lamellofus regularise from 
Andrariim in the province of Skone, 
Hunneberg and Billingen in the pro- 
vince of Weftergottland, Rodoen in 
the province of Jemtland, and the 
ifland of Oeland, &e.^ 
2. Undulated and wedge-like, with a 
fliining furface, Schiffus aluminofus un- 
diilatiis et cuneiformis fj[furis fplenden^ 
tibus. 
I'ifls at the firft fight refembles pit 
coal •, it is found in great abundance ia 
the pariih of Nas in Jemtland f. 
f In England, the great alum works at Whitby, in York- 
ihirp, §re of t]iis kind, D. C, ' ' 
, t purity above-mentioned i.) of the earth of the 
Of’ paoh alum, is meant with the fam'e reiliidion 
‘ ^ 
