From STRONTIAN. 13 



are delicate flender prifms, fometimes two inches long, having 

 a foft filky appearance. If the refrigeration has been very gra- 

 dual, the prifms will be formed lefs delicate, and of a more di- 

 ftinguifliable fhape. All of them are hexagonal, fome having 

 all their fides equal, others having two broad fides, with two in- 

 tervening narrow ones, while another fort is feen with three 

 broad alternating with three narrow fides. At one time they 

 end abruptly, at another an obtufe trihedral pyramid terminates 

 them, and now and then they are feen pointed like a needle. 



29. By the facility of cryftallization, and by the peculiar 

 form of the cryftals, this earthy fait may be eafily dete<5led 

 wherever it exifts in folution. For this purpofe, put a few 

 drops on a plate of glafs, and the muriate will foon difcover 

 itfelf by fhooting into its long flender needles, which are often 

 difpofed in a radiated form. 



30. These cryftals, after they are thoroughly dried, fufFer 

 little change from expofure to air, yet when the atmofphere is 

 greatly loaded with moifture, they are apt to deliquefce. Their 

 folubility in water is great. At temperature 60, one ounce of 

 diftilled water is capable of difTolving one ounce, four drachms 

 and one fcruple. To the fame quantity of diftilled water, kept- 

 boiling on a fand bath, I added in fuceeffive portions four 

 ounces of the fait, which became fluid, and I imagine I might 

 have added any quantity more with the fame event, as the tem- 

 perature of the folution, when boiling, feems fufhcient to ena- 

 ble the water of cryftallization itfelf to diftblve the faline mat« 

 ler. 



31. If into a faturated folution, fome ftrong muriatic acid be 

 thrown, a precipitation inftantly happens. The matter that 

 falls down is the fait in fmall needle form cryftals, and the fe- 

 paration of them from the water arifes from the force with 

 which the acid attrads the fluid, being greater than that exert- 

 ed by the fait to retain its folvent. 



32. The 



