826 



BOTANY AND PHARMACOGNOSY. 



Forms observed: Base (ooi) ; unit prism (no) ; brachydome 



(on). 



Angles: Angle iioAiIo = 50 40Y (normals). 



Habit : Crystals tabular on the base. The smaller crystals 

 are combinations of base (001) and prism (no) (Fig. 95, a); 

 often with one or both of the acute angles of the prism trun- 

 cated by the faces of the brachydome (on) (Fig. 95, b). In 

 the larger crystals the brachydome is more developed, and the 



Fig. 331. Brucine sulphate: orthorhombic crystals from aqueous solution. 



crystal is either equidimensional (Fig. 95, c) or elongated on 

 the a axis (Fig. 95, d). 



Optical properties: 3= a; h^b; C=<:. Axial plane the 

 brachypinacoid. Bxa^c. Optical sign +. Axial angle large, 

 2V:^ca. 87. 



BRUCINE SULPHATE [Co3H26N204)2HoS04 + 3^HoO] , 



Occurrence : See p. 437. 



Brucine is always associated in the plant kingdom with 

 strychnine. It contains two methoxyl-groups and is looked upon 



