212 VETEEINAEY TOXICOLOGY 



order, varieties of Cotyledon — viz., C. ventricosa, Echloniana, 

 and orbiculata — are quoted as poisonous, and causing the 

 C'Nenta disease [q.v.). 



UMBELLIFER^. 



The umbel family contain important poisonous plants, 

 of which those belonging to the genera Conium, Cicuta, 

 (Enanthe, ^thusa, and Ghceropliyllum (Anthriscus) are the 

 commonest. 



Conium. 



The only member of this genus is the very common and 

 well-known Conium maculatum, or spotted hemlock, the 

 poisonous nature of which has been known for centuries. In- 

 fusion of the hemlock was a favourite poison among the 

 Greeks, and was the agent of the official suicide of 

 Socrates. 



Botanical Characters. — Conium maculatum (Fig. 28), or 

 spotted hemlock. An erect, branching annual or biennial, 

 3 to 5 feet high, or sometimes more, glabrous, and emitting 

 a nauseous smell when bruised. Leaves large and much 

 divided into numerous small ovate or lanceolate deeply 

 cut segments ; the upper leaves gradually smaller and 

 less divided. Umbels terminal, not large for the size 

 of the plant, of 10 to 15 rays. Bracts short and lanceo- 

 lated ; those of the general involucre variable in number ; 

 those of the partial ones turned to the outside of the 

 umbel. Fruit about 2 lines long. The stem is often con- 

 spicuously marked with purplish-red spots. The plant is 

 common on the banks of streams, in hedgerows, and the 

 borders of fields. 



Active Principle and Doses. — In the green state all the 

 parts are poisonous, less so in northerly than in southerly 

 latitudes, the root containing only small quantities of the 

 active volatile alkaloid conine. Slow drying or boiling 

 results in the loss of most of this volatile alkaloid. The 

 plant is liable to be eaten more particularly in early spring ; 



