792 SOLANDRINE, A NEW MIDRIATIC ALKALOID, 



The liquid left in the retort from the first distillation contained 

 the whole of the alkaloid, which was recovered by shaking out 

 with chloroform, and now weighed 0*164 gram. This much 

 purer material was used for the subsequent examination. 



Chemical i^roperties. — The material as obtained in the above 

 manner is a yellow viscous mass, which becomes quite fluid on 

 gently warming. It is quite free from odour, even on heating. 

 The solubility in benzene and ether is slight; it is very soluble in 

 chloroform and in alcohol; but slightly soluble in water, giving 

 au alkaline solution and possessing a bitter taste. All attempts 

 to crystallise it failed, hence the difliculty of its purification. 



The aqueous solution gave well marked ppts. with the follow- 

 ing alkaloid reagents: — I in KI, picric acid, phosphotangstic 

 acid, tannic acid, AuClg, PtCl4,and KI.HgT2. In Vitali's test 

 a bright purple colour was obtained. 



Phenolphthalein is not reddened. HgClo 5 % in alcohol, gives 

 a white precipitate (atropine gives j'ellow, and red on w^arming). 

 PtCl4 gives, in a strong solution after standing some time, perfect 

 yellow cubical crystals, which decompose at 170°C. AuClg 

 yields two kinds of crystals, transparent colourless cubes and 

 octohedra, mixed with irregular yellow crj'^stalline masses. With 

 picrie acid, radiating groups of prisms are obtained showing 

 many curved and feathery crystals. 



10 mgms. of the alkaloid were next h3^drolysed with barium 

 hydroxide, and on separation of the products of hydrolysis there 

 were obtained, first, an acid which crystallised on evaporation in 

 long thin needles having a melting point of 106°C ; and secondly, 

 a basic substance which resembled the original viscous yellow 

 alkaloid in appearance, but formed a very different platinum salt. 

 The quantity was not sufficient to decide whether the base is 

 tropine or oscin. From 10 mgms. of the alkaloid were obtained 

 by hydrolysis 35% of an acid possessing the identical m. point 

 and properties of atropic acid, and 30 % of an uncrystallisable 

 base. This ratio of acid to base is equal to 1*17, which is the 

 exact theoretical ratio of tropic acid to tropine in the well 

 known atropine group. 



