HEMLOCK CONINE 519 



parsley (^Ethusa cynapium), water hemlock or cowbane 

 (Cicuta virosa), the fine-leaved water hemlock (Phellandrium 

 aquaticum), the water parsnip (QEnanthe crocata), are 

 Umbelliferae with physiological actions similar to those of 

 conium maculatum, and when freely eaten have poisoned 

 many of the domestic animals. Of wholesome dietetic 

 Umbelliferse, parsley, parsnip, and celery are illustra- 

 tions. The natural family is rich in aromatic carminative 

 seeds. 



ACTIONS AND USES. Hemlock and its alkaloids have many 

 points of resemblance to curare and nicotine. The chief 

 action of conine is to paralyse motor nerve-endings, so 

 giving rise to more or less complete paralysis, with 

 weak, staggering gait and then a gradual failure of re- 

 spiration. 



GENERAL ACTIONS. Hemlock was the state poison of the 

 Athenians, the death-potion of Socrates. The alkaloid 

 conine especially paralyses motor nerve-endings and so 

 produces weak, staggering ataxic gait, and then complete 

 paralysis. At the same time certain nerve cells are para- 

 lysed as with nicotine, so that vomiting and diarrhoea may 

 occur from paralysis of the inhibitory sympathetic ganglion 

 cells in the abdomen. Similarly the heart beats quicker 

 from depression of vagal ganglion cells and blood-pressure 

 falls from vaso-dilation. On the central nervous system 

 it exerts a primary, brief, stimulant action, followed by 

 depression. Thus there is twitching, tremor, quickened 

 respiration, then slower, shallow breathing (diaphragm 

 paralysed or centre ?), asphyxial convulsions, and death. 

 Death results from paralysis of respiration. It is excreted 

 by the kidneys. It acts more powerfully on man and 

 carnivora than on herbivora. Goats with impunity eat 

 considerable quantities of the fresh leaves (Kaufmann). 

 Its physiological antagonists are nux-vomica, strychnine, 

 and other tetanisers. 



Toxic ACTIONS. Harley and Mavor gave a two-year-old 

 thoroughbred colt six, eight, and twelve ounces of succus 

 conii without appreciable effect. Sixteen ounces produced 

 in twenty-five minutes dulness and stupidity, drooping 

 and swollen eyelids, but no change in the pulse or pupils. 



