222 SALTS. 71. Alumen. 



Found in Britain near Whitby^ in Sivitzerland^ Tufcanyy and at 

 Z« T^olfa near T^owf, forming iirata or vaft malles, with fre- 

 quently fmall lumps of pyrites or fulphate of iron interlperfed, 

 and having fometimes veins of white quartz running through 

 it: does not effervefce with acids, is of a white, grey, per- 

 laceous, or rofy colour, and produces alum upon combuftioij 

 or after long expofure to the air. 



commune. Not emitting vapours when fiilphuric acid is poured upon 

 it, mixed with bituminous Ihift. 

 Alumen fchilii. Syji. nat. xn. -2,. p. loi, n. 2. 

 Alumen lapide fiffile mineral. IVall. 2. p. 35. ti. 6, 

 AgilJa martialis, Crond. miner. feSi» 124. 2. 3* 

 Slaty and compact Alum ores. Kirivan miner. 2. p% i.g. 

 Aluminous earth. Schmeijjer miner, i. p, 171, 

 Alumina. Thomfon chem. i. p. 519. 



J. Very foft to the touch, meagre, breaking into trapezoid frag- 

 ments. 

 Shift, aluminof. lamellof. Cronft. min. 124. 2. 3. i. 

 Ka*-ft, magaz* Ilel-u. natur, 3, p. 204. 

 Hoffm^ Bergm*'Journ. 1788. 2. p. 550, 



2. Hardilh, fliining internally, undulately flaty, a little greafy to 



the touch, breaking into indeterminate fragments. 

 Schilf. aluminar. undulat. Cronft. min. 124. 2. 3. 2. 

 Karft, ?naga%. Hi In;, naiur. 3. p. 205, 

 Hoffjn. Berg, Journ. 1788. 2. /. 501. 



3. Slightly efFervefcing with acids. 



Alum, lapide calcareo, Wall.Jyst, 2. p. 35. «. 5, 



Found in the neighbourhood of coal-mines in various parts of 

 England^ Scotland^ and Walesy in Siberia, Nor^-vjay, Snveden, 

 many parts of Germany^ &c. forming vaft mountai'.s, and 

 ftrata over coals and iron ore ; it is alfo found in fmall flatted 

 fpherical malles, containing fmall particles of fulphuret of 

 iron in the form of pyrites : colour black, gives a dark grey • 

 ftreal<, adheres a little to the tongue: texture ^^ty, fome- 

 times ftraight, fometimes curved, and has a fweetifh and 

 fomewhat aftringent tarte, and is apt to wither in the air into 

 a dull grey powder. It is ufed in alujn works. 



tHrfa. Not emitting vapours when fulphuric acid is poured upqn 



it, mixed with turt. 

 Alumen turfa mineralis. Wall./yfi. 2. /. 33. 

 Sijuab. ASi.Ztockh. 28./». 37. Kirivan min. 2- p. 20. 

 Found near Elfimburg in Snvedeny and in France^ and confifts of 



turf fo impregnated with fulphuret of iron as to yield a fmall 



portion of alum. 



