830 BOTANY AND PHARMACOGNOSY. 



alcohol ; 3.8 parts of ether ; and one part of chloroform or 

 benzene. It is insoluble in glycerin. The individual crystals as 

 usually obtained on a microscopic slide vary in length from 0.4 

 mm. to 2 mm. (Fig. 157, A). 



Cocaine. Crystals from dilute alcohol, or a mixture of 

 alcohol, ether and chloroform. 



Monoclinic : a: b: c ^ 0.8432 : i : 1.032 ; ^ = 73 50'.* 



Forms observed : Base (001); orthopinacoid (100); prism 

 (no); and clinodome (oli) (?). 



Angles : Angle on the base between the prism-base edges 

 (ooi-i 10 Aooi-Iio) = 99 44' (normals) . 



Habit : Tabular on the base, elongated along the b axis. 

 The crystals are apparently hemimorphic, the termination on 

 one end of the b axis being the prism faces, and on the other 

 end the clinodome. This hemimorphism is, however, not certain. 

 It was not observed by Fock (loc. cit.). 



Optical properties : As viewed on the base, the elongation 

 of the crystal (b axis) is the direction of least refractive index. 

 The optical orientation further than this was not determined. 



Cocaine Hydrochloride (Ci-H^jNO^.HCl). 



Cocaine hjtirochloride occurs in two forms, the hydrous salt 

 crystallizing from aqueous solutions ; and the anhydrous, from 

 non-aqueous solvents, such as alcohol. The latter is supposedly 

 the official salt and is erroneously stated in the U. S. P. to 

 crystallize in monoclinic prisms. At 25 C. one part of cocaine 

 hydrochloride is soluble in 0.4 part of water ; 2.6 parts of 

 alcohol; 18.5 parts of chloroform; and 4 parts of glycerin. The 

 microscopic crystals of the anhydrous salt may attain a length 

 of 3 mm. (Fig. 157, B). The hydrous salt affords long needles 

 or elongated plates, which, when crystallized on a microscopic 

 slide, may be as much as 20 mm. long. 



Cocaine Hydrochloride (anhydrous). Crystals from solu- 

 tion in a mixture of equal parts of alcohol and chloroform. 



* Tschermak in Lossen's paper, Ann. Chem. Pliarm., 1865. 133, p. 355. 

 See also A. Fock. Zeitschr. f. Krysiallog., 1890, 17, p. 370. 



