PHYSIOGRAPHY. 1ST 



Epsom Salt Erinite. 



truncation of the pyramidal edges. Fracture, conchoidal. 

 Surface, crystals striated vertically upon their lateral planes. 



Lustre vitreous. Color white. Streak white. Trans- 

 parent . . . translucent. 



Rather brittle. Hardness2-0 . ..2-5. Sp.gr. = l-751. 

 Taste saline and bitter. 



Compound Varieties. Botryoidal, reniform, and in the 

 shape of crusts: composition columnar, if the particles are 

 very delicate, the lustre becomes pearly. Pulverulent. 



1. It deliquesces before the blow-pipe, but is with difficulty fusible, 

 if its water of crystallization has been driven off. It dissolves very rea- 

 dily in water. 



2. Analysis, 



By VOGEL. 



Water .... 48-0 



Sulphuric acid .... 33-0 

 Magnesia '. 18-0 



."5. It effloresces from several rocks, both in their original repositories, 

 and iu artificial walls. It forms the principal ingredient of certain min- 

 eral waters. 



4. It occurs in Freiberg, and in its neighborhood, efflorescent upon 

 gneiss; likewise in Scotland, in the Hartz, in Berchtesgaden, in Salz- 

 burg, at Idria in Carniola, in Bohemia and in Hungary. 



It abounds in the limestone caves of Kentucky and Indiana, whose 

 floors are often covered with it in delicate crystals, intermingled with 

 dry earth to a considerable depth. In New York also, ten miles from 

 Coeymans, on the east face of the Helderberg, it effloresces from the 

 calcareous sandstone. 



5. After having been purified, it is employed in medicine, as well as 

 for the production of magnesia. 



ERINITE. Dystome Copper-Baryte. 



Highly crystalline : the individuals arranged in concen- 

 tric coats, with rough surfaces, produced by the termina- 

 tion of exceedingly minute crystals ; the layers often not 



