130 SOME POISOXOUS PL\NTS IV N.O. SOLANACE^. IV., 



cost £10 per oz., and its salts, including the sulphate, £5 per 

 oz. In 1916, British catalogues contain duboisine sulphate at 

 £25 per oz. Its use is almost entirely confined to ophthalmic 

 Avork, and as each of these alkaloids is powerfull}^ midriatic, a 

 variation in the composition of the mixture affects but little the 

 main result. This is in marked contrast to the action on the 

 central nervous system, where hyoscyamine acts as a stimulant, 

 and scopolamine as a depressant and hypnotic. The relative 

 midriatic values are given as : — 



Scopolamine ... 20 (Bastedo's Mat. Med., 384). 



Lsevo-hyoscyamine 16 (Cushny). 



Atropine 8 (Wynter Blyth's Poisons, 384). 



Norhyoscyamine.. 2 (Carr and Reynolds, J. C.S. 1912,948). 



Nor-atropine ... 1 ,, ,, 



Before 1880, duboisine was recognised as closely resembling, 

 but not identical with atropine. 



In 1880, Ladenburg found it to be entirely hyoscyamine. 

 Harnack emphasised that it was much stronger. 



In 1887, Ladenburg isolated only scopolamine, no other 

 being present. 



In 1890, Schering and Co. separated both hyoscyamine and 

 scopolamine. 



In 1891, Bender obtained from one sample of leaves only 

 hyoscyamine, and from another diiferent sample only scopola- 

 mine. Schmidt repeated and confirmed Bender's results. 



In 1892, Schmidt obtained inactive scopolamine only. Merck 

 obtained pseudo-hyoscyamine, hyoscyamine, and scopolamine. 



In 1912, Carr and Reynolds separated nor-hyoscyamine 

 (Merck's pseudo-h.) and hyoscyamine only, no scopolamine being 

 present. 



In 1916, the writer examined an old sample of commercial 

 duboisine purchased from Messrs. Baird and Tatlock, of London. 

 He isolated from the gold salts a fraction with the melting-point 

 of Isevo-scopolamine, a second fraction containing nor-hyoscya- 

 mine, and a third containing laevo-hyoscyamine. A considerable 

 proportion of the alkaloids separated as viscous particles on 

 further concentration of the mother-liquors. 



