From srRONTIAN. S 



a centre. The uniformity of this radiation is frequently in- 

 terrupted by the fibres proceeding from different points of con- 

 vergence, croffing and interfecfling each other. Occafionally on 

 the furface, but more frequently in vacuities within the mafs; 

 the mineral is difcovered fhooting into flender prifmatic or co- 

 lumnar cryftals of various lengths. Some of thefe end obtufe- 

 ly, others of them in a fharp point ; they are generally flriated, 

 and have fix fides. I have feen thefe cryftals traverfing the cavi- 

 ties in the form of the fineft and mofl delicate fpiculas, and 

 when difpofed in a radiated form, equalling in delicacy, and 

 refembling in appearance, the moft exquifite zeolites. In other 

 portions, the ftriated fibrous contexture is fcarcely difcernible. 

 Sometimes the Strontian fpar is tranfparent and colourlefs, more 

 commonly it has a tinge of yellow or green, and fome diver- 

 fity is obfervable in the depth of the tint. 



4. It is not fo hard as to fcintillate ; it may be fcratched by 

 a knife ; it readily yields to the ftroke of the hammer ; it has 

 no particular fra<5Iure, though it commonly breaks along the di- 

 redion of the fibres. 



5. It is a heavy fpecies of fpar, having a fpecific gravity, go- 

 ing between 3.650 and 3.726. 



Chemical ^alities. 



6. This mineral to the tafte is infipid, and is only in a fmall 

 degree foluble in water. 1 boiled ten grains of it, reduced to 

 a very fine powder, in four ounces of diftilled water for fome 

 time ; about two grains and a half were difFolved. 



7. It is powerfully attacked by feveral of the acids, and a fo- 

 lution takes place in fome of them. This is accompanied by a 

 lively and brifk efFervefcence, which in this as in every other 

 inftance, proceeds from the difengagement of an aerial fluid. 



8. The gas that arifes during a folution of this mineral in 

 muriatic acid, extinguifhes the flame of a candle, and is ab- 



forbed 



