26 . HEPATICUg. 
27. Fluor. 
. 23 . Apatites. 
29. Boracites. 
[ 61 ] 
When feraped or expofed to heat fmelling , 
like liver of fuiphiir. 
Int'ufed i[i hot fniphiiric acid emits a gas 
which corrodes and diifolves glals. 
When fpriiiklcd on red hot charcoal emits a 
green phpfphorercent flame, . pot ealily 
melted. 
Cubic, liard, IcmitranTparent. 
ORDER IV. ARGILLACEOUS. 
30. Aluxjinaris. Dry and harlh, folublc almofl; e.itircly in 
nitric acid. 
31 Argilla. 
32. PuTEOLANA. 
33. CAiMENTUM. 
34 - . Cariosus. 
35 - Ardesia. 
Grealy to the touch, plaftic, hardetiing by 
fire. 
Friable, hardening in the air when kneaded 
with water and quicklime. 
Solid, ha deiiiug in the air when pounded 
and knead-d with w'ater and quicklime. 
Rough, filling into powder in water. 
FifliVe, when moilkrted giving out an argil- 
laceous odour. 
36. Easaltes. 
37 - Lava. 
3 ^. IVlicA- 
39 - Opalus. 
40. Zeolithu?. 
SCORLUS. 
Ppake, viihont luftre, compand, ot a didl 
colour, ealily motildering into pieces, mc.t- 
ing into a blackifli glafs before the blowpipe, 
The'prodticeof volcanos or fubterraneous fires. 
Scaly, Ihining. 
Of no determinate fliapc when broken, corn- 
paft, melting with the grcateli: difficulty, 
tafily melting with ebullition, and in melt- 
ing emitting a phofphorefcent liidit. 
Melting,but emitting nophofpborefecnt light. 
ORDER V. SILICEOUS. 
42 . Gemma. 
43. Olivinus. 
44. Feldspatum. 
45. Pyromachu.s. 
46. Petrcsilex. 
Cryflallinc, hard and very hard, ihining ir. 
the dark. 
Ealily falling to pieces in the air, melting 
with great difficulty. 
Lamellar, melting with foda into a tranfpR- 
rent glafs: mouldering in the air. 
Not mouldering in the air, ormeltiitg without 
the grcatelt degree of heat, breaking into 
convex fragments. 
Melts without ebullition, of ffiivery frafture. 
