ORDER IV. OCTAHEDKAL AMMONIAC-SALT. 89 



well known to be mentioned here more at large. It shall 

 only be remarked, that for the greater part it is not used 

 in the state in which it is found in nature, but in that in 

 which it is obtained from evaporating its solutions. 



GENUS V. AMMONIAC-SALT. 

 1. OCTAHEDRAL AMMONIAC-SALT. 



Octahedral Sal Ammoniac. JAM. Sjst. Vol. III. p. 11. 

 Man. p. 11. Muriate of Ammonia. PHILL. p. 194. 

 Naturlicher Salmiak. WEEN. Hoff. H. B. Th. III. 1. 

 S. 219. Salmiak. HAUSM. III. S. 853. Salmiak. 

 LEON H. S. 631 . Ammoniaque muriate'e. HAU Y. Traits', 

 T. II. p. 360. Tabl. comp. p. 22. Traite 7 , 2de Ed. 

 T. II. p. 221. 



Fundamental form. Hexahedron. Vol. I. Fig, 1. 



Simple forms. H; 6(P), Vol. I. Fig. 2.; D,Vol. I. 

 Fig. 81. ; C i (*), Vol. I. Fig. 34. 



Char, of Comb. Tessular. 



Combinations. 1. H. O. Vol. I. Fig. 3. and 4. 



Cleavage, octahedron. Fracture conchoidal. Sur- 

 face smooth. 



Lustre vitreous. Colour generally white, often 

 inclining to yellow or grey. Sometimes it is 

 stained green, yellow, or black. Transparent 

 ... translucent. 



Very sectile. Hardness = 1-5 ... 2-0. Sp. Gr. 

 = 1-528. Taste acute and pungent. 



Compound Varieties. Stalactitic, botryoidal, glo- 

 bular, reniform shapes, also in crusts : composition 

 columnar. Massive: composition impalpable. Frac- 

 ture conchoidal. Sometimes in a state of mealy 

 efflorescence. 



