Ill] Umhelliferae 41 



Hemlock (Conium maculatum L.). This plant, famous from ancient 

 times as extremely poisonous, has a fetid, disagreeable odour — a mousy 

 smell — especially noticeable when the plant is bruised. It has caused 

 human poisoning in three ways : the seeds have been eaten in error for 

 anise, the leaves for parsley, and the roots for parsnips. 



Animals rarely appear to eat this plant, but cases have been recorded. 

 It is stated that in the United States many domestic animals have been 

 killed by it ; and Ewart says that it is responsible for poisoning a number 

 of cows in Victoria. Goats are believed to be largely immune to the 

 poison, or are less harmed than other animals, and sheep are stated to 

 eat the plant with impunity, though cases of poisoning are recorded. 

 Johnson and Sowerby state that horses have occasionally swallowed 

 considerable quantities without apparent effect, while Cornevin remarks 

 that to cause death a horse would need to eat 4 to 5| lb. of the fresh 

 plant, or a cow 8| to 11 lb. 



Hemlock is probably most dangerous to live stock in the spring, 

 when green herbage is least plentiful and the young shoots of hemlock 

 are fresh and short. Chesnut says that the root is nearly harmless in 

 March, April and May, but dangerous later, especially in the first year 

 of growth; but Esser states that it is only poisonous in the spring. 

 The foliage is more poisonous before flowering than after, when the 

 poisonous principle passes to the fruits, which are more poisonous before 

 ripening (three quarters ripe) than afterwards. Pott remarks that 

 after eating hemlock cows give milk with a bad taste. 



Toxic Principle. Early in summer the toxic principle appears to 

 be chiefly contained in the foliage, but later in the fruit, particularly 

 when still green. Among the substances contained in hemlock are the 

 toxic alkaloid Coniine (CgHiyN), the poisonous Coniceine (CgHigN), 

 Conhydrine (CgHi^NO), the alkaloid Meihylconiine (C9H19N), Pseudo- 

 conhydrine (CgHi^ON). Coniine may be described as an oily, colourless, 

 quite volatile liquid, quickly turning brown on exposure to the air, and 

 giving a mousy odour to the whole plant. The amount of Coniine in 

 the fresh leaves is given (Pammel) as 0-095 per cent., but in the ripe 

 seeds 0-7 per cent. Enghsh fruits contain much more of the total 

 alkaloids than imported fruits. Owing to the volatile character of the 

 poisons hemlock largely loses its toxicity when dried in hay, and is there- 

 fore the less likely to prove injurious to domestic animals. 



Symptoms. Hemlock is a dangerous narcotic plant. Even the 

 smallest quantities may cause inflammation of the digestive organs, 

 paralysis and death. The general symptoms are salivation, bloating, 



