MICRO-ANALYSIS. 851 



Optical properties: L = a; b = 6; C = c. Axial plane the 

 brachypinacoid. A good interference figure is observed on the 

 base, and although the emergence of the axes was not observed, 

 c is probably the acute bisectrix with the value of 2E, large. 



Strychnine Sulphate [(C2iH22N202)2-H2S04 -f 6H2O]. 



Occurrence : See p. 437. 



Strychnine crystallizes in anhydrous orthorhombic crystals 

 from alcoholic solutions. It forms crystallizable salts with the 

 various acids, as well as double salts with platinic chloride and 

 gold chloride. Of the salts, the sulphates are commercially the 

 most important. According to Rammelsberg * there are three 

 strychnine sulphates : ( i ) An acid salt, with two molecules 

 of water of crystallization (C21H22N2O0.H2SO4 + 2H.O) and 

 crystallizing in needles, crystal form not given. (2) A neutral 

 salt with 5 molecules of water of crystallization [ (C2iH2oN202)2-- 

 H2SO4 -f- 5H0O], orthorhombic ( ?), from hot aqueous solutions. 

 (3) A neutral salt with six molecules of water of crystallization 

 [(C2iH22N202)2-H2S04 -[- 6H2O], tctragoual, obtained from 

 aqueous solutions at the ordinary temperature. This latter is 

 the most characteristic form and is the one here described. 

 At 25 C. one part of strychnine sulphate is soluble in 31 parts 

 of water ; 65 parts of alcohol ; and 325 parts of chloroform. It 

 is nearly insoluble in ether. Crystals obtained on a microscopic 

 slide from solutions in water, alcohol, dilute alcohol or a mixture 

 of alcohol and chloroform vary in size from 0.40 mm. to 2.0 

 mm. (Figs. 342-344). 



Strychnine Sulphate. Crystals from aqueous solution. 

 Tetragonal trapezohedral : a: c ^ i : 3.3 12. f 

 Forms observed: Base (001); and pyramid of the first 

 order (221). 



Angles: Angle 221 A 221 ^ 24 6'. 



* C. Rammelsberg, B^er. d. deutsch. chem. Ges., 1881, 14, p. 1231 ; 

 abstract in Zeiischr. f. Krystallog., 1884, 9, p. 108. 



t Des Cloizeaux. See Groth's Physikalische Krystallographie (1905), 

 4th Ed., p. 431. 



