144 SOME POISONOUS PLANTS IX N.O. SOLAXACE^, V., 



sulphurous acid, filtering oft' the deposit of metallic gold, and 

 treating with a saturated solution of picric acid. These were 

 allowed to stand, the crystals were separated, recrystallised, 

 washed and dried, and their melting points taken. 

 (1.) Aurichloride m.p.l79°C. yields picrate with m.p.219-220^C. 

 (2.) „ 165 „ „ „ 163-166 



(3.) „ 136 „ „ „ 176 



(4.) „ 197 „ „ „ 180 



The above authorities have given the melting points of the 

 picrates of the pure alkaloids as follows: — 



Atropine picrate... ... ... m.p.l75-176X'. 



L?evo-hyoscyamine picrate ... m.p. 165 



Nor-hyoscyamine ,, ... m.p. 220 



Lsevo-scopolamine „ ... m.p.180-181 



From one gram of the crude alkaloid there was obtained 0*5 

 gm. of crystals of the gold salts. This quantity at the end of the 

 fractional crystallisation yielded approximately O'l gm. of scopo- 

 lamine salt, O'l gm. of nor-hyoscyamine salt, and 0'2 gm. of Itevo- 

 hyoscyamine salt. In other experiments, larger amounts were 

 obtained, but considerable proportions of a viscous uncrystallis- 

 able substance always separated. 



In the initial stages of the above crystallisation process (a, b, 

 and c), w^hen the crystals had been separated as much as possible, 

 the mother-liquors deposited yellow, amorphous, sticky particles. 

 When the solution was gently warmed, the amorphous substance 

 melted and floated on the surface like oily drops. This portion, 

 which contained part of the alkaloids, could not be induced to 

 crystallise, and further attempts to purify it did not alter its 

 viscous nature. 



Summary. 



The leaves of Duhoisia Leichhardtii contain a mixture of the 

 midriatic alkaloids, amounting to 1 '4 per cent, of the dried (at 

 100°C.) material or 0*28 per cent, of the fresh plant. By the 

 fractional crystallisation of their aurichlorides, the mixed alka- 

 loids were separated into nor-hyoscyamine, laivo-hyoscyamine. 



