4 



may occur. When extraction is complete the alcoholic solution is 

 evaporated to pasty consistency and repeatedly extracted with dilute 

 acid and finally water. The aqueous extracts are separated by filtra- 

 tion from any tarry matters and are then extracted while still acid 

 with chloroform and ether until no more colouring matter is removed. 

 The liquor is then made slightly alkaline with ammonia and again 

 repeatedly extracted with chloroform until the extracts show only 

 traces of alkaloid. For the purpose of testing the extracts for the 

 alkaloid Mayer's solution will be found convenient. The chloroform 

 solution is now dried with calcium chloride, and if necessary filtered 

 and evaporated to dryness, preferably under reduced pressure, though 

 now that water is absent this is of much less consequence than in the 

 other stages of the extraction process. When most of the chloroform 

 is evaporated the liquid becomes very viscous, and if left to cool 

 frequently crystallizes in very characteristic spherical tufts of exceed- 

 ingly fine needles. Before purification the crude alkaloid is generally 

 of a brownish colour, and when prepared in quantity the crystalline 

 mass obtained strongly resembles the mineral crocidolite in appearance. 

 In order to obtain the alkaloid in a pure state it is necessary to recrys- 

 tallize it a time or two from a mixture of benzene and petroleum spirit. 

 In the latter of these liquids it is quite insoluble, so that a suitable 

 mixture can be readily obtained. When pure, hyoscyamine forms 

 fine white needles having a melting point at 108 C. 



Hyoscyamine forms a well crystallized salt with gold chloride, 

 which when pure melts at 162 C.* When crystallized from dilute 

 hydrochloric acid it forms brilliant golden yellow plates. The picrate 

 is also a finely crystalline salt but slightly soluble in cold water. It 

 is of a brilliant canary yellow colour, and when pure melts at 167 C. 

 These two salts are both well characterized and serve for the identifi- 

 cation and purification of the alkaloid. 



Associated with the alkaloid in henbane there appears to be some 

 very strongly smelling body which in small quantity reminds one of oil 

 of winter green (methyl salicylate), though when much is present the 

 odour more resembles that of nicotine. 



* It may be pointed out here that this melting point agrees with that given by Henry, but 

 it is several degrees higher than that recorded by Dunstan and others. It would appear that 

 their figures are some degrees too low. When pure the melting point is fairly sharp. 



