COCAINE 



357 



insoluble in glycerin. The individual crystals as usually obtained 

 on a microscopic slide vary in length from 0.4 mm. to 2 mm. 1 



Cocaine hydrochloride occurs in two forms, the hydrous salt crys- 

 tallizing from aqueous solutions; and the anhydrous, from non- 



Flo. 158. Crystals of cocaine-chloro-aurate. To 1 c.c. of a dilute solution 

 (1:300) of cocaine are added 3 drops of gold chloride test solution, avoiding 

 shaking as in the case of the platinum chloride test. A precipitate immedi- 

 ately forms and slowly changes from the amorphous into the crystalline state. 

 Under the microscope, the crystals resemble fern-fronds, generally with a 

 stellate arrangement. In dilutions of 1:12,000, similar crystals form after 

 long standing. 



With the gold test, alpha-eucaine gives branching, twig-like crystals; sto- 

 vaine gives large crystals resembling those of cocaine chloroplatinate in gen- 

 eral structure, but differ in that the branches possess smaller branches, which 

 is not the case with the cocaine chloroplatinate. Amorphous precipitates 

 are given with beta-eucaine, acoine and holocaine. Euphthalmine gives 

 no precipitate. After Seiter and Enger, Amer. Jour. Pharm., 1911, p. 195. 



aqueous solvents, such as alcohol. The latter is supposedly the 

 official salt and is erroneously stated to crystallize in monoclinic 

 prisms. At 25 C. one part of cocaine hydrochloride is soluble in 



1 Tschermak in Lossen's paper, Ann. Chem. Pharm., 1865, 133, p. 355. 

 also A. Fock, Zeitschr. f. Krystallog, 1890, 17, p. 370. 



See 



