300 TTMBELLIFER^. 



devoid of vittpe. When a mcricarp is cut transversely, the seed exhibits 

 a reniform outline, due to a deep furrow in the albumen on the side of 

 the commissure. 



The fruits of hemlock are dull greenish grey, and have hut little 

 taste and smell; hut when triturated with a solution of caustic alkali 

 they evolve a strong and offensive odour. 



Microscopic Structure — Hemlock fruits differ from other fraits 

 of the order by the absence of vittoe.^ In the endocarp, there is a 

 peculiar layer of small nearly cubic cells surrounding the albumen. 

 The cells of the endocarp are loaded with a brown liquid consisting 

 chiefly of conine and essential oil. 



Chemical Composition — The most important constituent of tk 

 fruits of hemlock Conine or Conia, C'H"NH, a limpid colourless oily 

 fluid, 0-84G sp. gr. at 12°-5 C. It has a strong alkaline reaction, and boils 

 at 170°C. in an atmosphere devoid of ox3^gen, without decomposition. It 

 was first observed by Giseke at Eislcben, Saxony, in 1827, recognized 

 as an alkaloid by Gciger in 1881, and more amply studied by Wertheim 

 in 1856 and 18G2. To obtain it, an alcoholic extract is submitted to dis- 

 tillation with a little slaked lime. The product should be neutralized vritli 

 oxalic acid, and the oxalate of conine removed by absolute alcohol misea 

 with a little ether, oxalate of ammonium being insoluble. The oxalate 

 of the alkaloid shaken with caustic lye and ether, affords the conme on 

 evaporating the solvent and distilling the alkaloid in a current ot dry 

 hydrogen. In the plant it is combined with an acid (malic?), and ac- 

 companied by ammonia, as well as by a second, less poisonous crystamz- 

 able base, called Conhydrine, C'H%0, which may be converted niw 

 conine by abstraction of the elements of water. From these alKaloids 



H 



fre- 

 con- 



by Wertheim. Even in nature one hydrogen atom of conine is 

 quently replaced by methyl, CH'; and commercial conine comnw^/^^^, 

 tams, as shown by A. von Planta and Kckule, methyl-conine, yH i^^ _ 

 Lastly there is present in hemlock fruits a third alkaloid having p 

 bably the composition CH^'N. . of 



As to the yield of conine, it varies according to the development 

 the fruits, but it is at best only about \ per cent. According to ^cn 

 (1870), the fruits are most active just before maturity, provided tney 

 gathered from the biennial plant. At a later stage, conine is ptoo ^j^ 

 partly transformed into conhydrine, Avhich However is present in 

 very small proportion, — about 1-^ per mille at most. . , j^gs 



In its deleterious action, conine resembles nicotine, but is mu 

 powerful. 1 • (Tof 



Schiff (1871-1872) has artificially produced an alkaloid pal•t'^^'[)°^ . 

 the general properties of conine, and having the same co^P^^, ^j^s 

 but it is optically indifferent. Conine, on the other hand, we tim 

 the plane of polarization to the right. ^ .inyoid 



The fruits of hemlock contain also a volatile oil which appears " 

 of poisonous properties ; it exists in but small quantity and Jias n 

 been fully examined. 



of the 



Uses—The fruits of hemlock are the only convenient source o ^^^^ 

 alkaloid conine. They were introduced into British mcdicnie m lo ^^,^ 



» See Moynler de ViUepoix, Annaks des Sciences naturelks, Botanique, v. {18< 



