46 PHYSIOGRAPHY. 



CLASS 1. 



G. The salt which goes by the name of Blue Vitriol from 

 Goslar, though it contains sulphate of copper, is not tetar- 

 to-prismatic Vitriol-salt, since its forms are not tetarto- 

 prismatic, but hemi-prismatic, and similar to those of the 

 hemi-prismatic Vitriol-salt. Its colour is sky-blue, but 

 considerably paler than that of tetarto-prismatic Vitriol- 

 salt. Besides sulphate of copper, it also contains sulphate 

 of zinc, and is probably one of the salts expressed by the 

 general formula 11 S 2 + 12 Aq. of MITSCHERLICH, upon 

 which supposition it would consist of 14-95 Oxide of Copper, 

 13-83 Oxide of Zinc, 29-94 Sulphuric Acid, and 41-28 Water. 



3. PRISMATIC VITRIOL-SALT. 



Pyramidal Vitriol or White Vitriol. JAM. Syst. Vol. III. 

 p. 21. Man. p. 75. Sulphate of Zinc. PHILL. p. 

 356. Natiirlicher Vitriol. WEEN. Hoffm. H. B. Th. 

 III. 1. S. 235. Zink- Vitriol. HAUSM. III. S. 1118. 

 Zink- Vitriol. LEONH. S. 314. Zinc sulfate. HAUY. 

 Traite', T. IV. p. 180. Tabl. comp. p. 104. Trait*?, 2de 

 Ed. T. IV. p. 198. 



Fundamental form. Scalene four-sided pyramid. 

 P = 12727'; 12645'; 785'. Vol.1. Fig.9. R.G. 



a : b : c = 1 : V 3-0407 : V 3-0037. 



Simple forms. P (1) ; P + oo (M) = 90 42' ; 



(Pr) 3 ; (Pr + <x) 3 = 53 25'; Pr = 120 20'; 



Pr + oo (o) ; Pr = 120 3' ; Pr + oo. 

 Char, of Comb. Hemi-prismatic, of inclined faces. 

 Combinations. 1. P. P + oo. 



2. P. P + oo. Pr + oo. Sim. Fig. 6. 



3. Pr. P. P + oo. Pr + oo. 



4. Pr. Pr. P. (Pr)'. P + oo. (Pr + oo)*. 

 Pr + oo. 



Cleavage. P r + oo, highly perfect ; Pr, less dis- 

 tinct. Traces of P + oo, Fracture conchoidaL 



