CHEMICAL ANALYSIS OF SOME CALAMINES, 79 



b. One of thefe cryflals, expofed to the flame of the blow- Blowpipe ex- 

 pipe, decrepitated and became opaque, and fhone with a green 



light, but feemed totally infufible. 



Borax and microcofmic fait diflblved thefe cryftals, without 

 any efFervefcence, producing clear colourlefs glafles. Carbonate 

 of foda had little if any adion on them. 



c. According to Mr. Pelletier's experiments * on the cala- 

 mine of Fribourg in Brifgaw, which is undoubtedly of this 

 fpecies, its compofition is. 



Quartz 0.50 



Calx of zinc - - - - 0.33 

 Water - - - - - 0.12 



1.00. 



The experiments on the Regbania cryftals have had different 

 refults ; but, though made on much fmaller quantities, they 

 will perhaps not be found, on repetition, lefs in conformity" 

 with nature. 



23. 45 grs. heated red hot in a covered crucible, decrepitat- 

 ed a little, and became opaque, and loft 1.05 grs. but did not 

 fall to powder or grow friable. It was found, that this matter 

 was not in the leaft deprived of its ele61rical quality by being 

 ignited ; aad hence, while hot, the fragments of thefe decrepi- 

 tated cryftals clung together, and to the crucible. 



d. 22.2 grs. of thefe decripitated cryftals, = 23.24' grs. of 

 the original cryftals, in a ftate of impalpable powder, being 

 digefted over a fpirit-larap wdth diluted vitriolic acid, fliowed 

 no efFervefcence ; and, after fbme time, the mixture became a 

 jelly. Exhaled to drynefs, and ignited flightly, to expel the 

 fuperfluous vitriolic acid, the mafs weighed 37.5 grs. 



On extradion of the faline part by diftilled water, a fine 

 powder remained, which, after ignition, weighed 5.8 grs. and 

 was quartz. 



The faline folution afforded, on cryftallization, only vitriol Component 



of zinc. Thefe cryftals therefore confift of, P"'^ of eleftrl- 



' cal calamins. 



Quartz - - . - 0.250 



Calx of zinc - - - - 0.683 

 Water 0.044. 



0.977 

 Lofs ..-.-- 0.023 



1. 000. 

 • Journal de Phyfique. Tom. XX. p. 414. 



The 



