ODDER II. PRISMATIC HAL-BARYTE. 



ryte, which generally occurs in the higher parts of the 

 veins, hexahedral Lead-glance and dodecahedral Garnet- 

 blende, with several Lime-haloides, and other species ; it 

 is also found in lead-veins traversing greywacke, and in 

 irregular beds along with paratomous Lime-haloide in clay 

 slate. 



3. Large quantities of this species are found in England, 

 in the counties of Durham, Westmoreland, Lancaster, and 

 Salop, in veins ; also near Neuberg in Stiria in irregular 

 beds. It has been mentioned from Hungary, Salzburg, 

 Siberia, Sicily, and other places, where it seems to occur 

 only in small quantities. 



4. It is a violent poison, and has been used in several 

 parts of England for killing rats. 



3. PRISMATIC HAL-BARYTE. 



Prismatic Baryte or Heavy-spar. .JAM. Syst. Vol. II. p, 

 398. Man. p. 71. Heavy spar. Sulphate of Barytes. 

 PHILL. p. 183. Schwerspath. WERN. Hoffm. H. B. 

 III. 1. S. 155. Baryt. Hepatit. HAUSM. III. S. 991. 

 1000. Schwefelsaurer Baryt. LEONH. S. 606. Baryte 

 sulfate'e. HAUY. Traite', T. II. p. 295. TabL comp. p. 

 12. Traite', 2de Ed. T. II. p. 5. 



Fundamental form. Scalene four-sided pyramid. 

 P = 128 23', 91 2(f, 110 44'. Vol. I. Fig. 

 9. R. G. 



a : b : c = 1 : V 1 '7045 : J0662?. 



Simple forms. P OD (&); P (2); P + QD (n) 

 = 106 ?' ; (P) 3 = 69 9'* ; (P + <x) 3 = 47 

 49' ; (P 2) 4 = 74 54' f ; (P) 4 = 5440 / * ; 



" The faces of these pyramids occur with parallel edges of 

 combination between the faces of z and P ; the angle given is 

 that which two faces will produce, if enlarged to their inter- 

 section over the face M. H. 



f This edge of the pyramid possesses the same inclination 

 towards the principal axis, as the edge of 113 44' in (Pr I) 3 

 (//), which corresponds to the obtuse terminal edge of the fun- 



