Cornevin says that this plant causes the poisoning of animals every year—they eat it willingly, showing an enfeebled instinct owing to domestication. The plant is poisonous in all its parts, the root being the most toxic, and drying does not destroy the toxic property. Cornevin gives the following quantities of the fresh root as necessary to poison various animals:—
Horse 0·100 per cent. of the live weight. Ox 0·125 „ „ „ Sheep 0·200 „ „ „ Pig 0·150 „ „ „ Rabbit 2·000 „ „ „
Holmes described _Oenanthe crocata_ as the most dangerous and virulently poisonous of all our native plants (_Pharm. Jour._, 1902).
Other species of _Oenanthe_ are also poisonous in a less degree—_e.g._ _O. fistulosa_ L., and _O. Phellandrium_ Lamk.
_Toxic Principle._ Poehl (1895) obtained from the root of this species an amorphous neutral product which he designated _Oenanthotoxin_. The latest investigation is that by Tutin, who examined entire dried plants collected in early spring, and the experiments confirmed the conclusion arrived at by Poehl, that the toxic principle is a neutral resin. A dark-coloured, viscid resin, insoluble in water, and equal to 3 per cent. of the weight of the plant, was extracted, and it is stated that the neutral portions of the petroleum and ether extracts of this resin represent the toxic principle of the plant. As there is no evidence of the homogeneity of this product, and it is probably complex in character, it was given no name or formula. The fact that it has poisonous properties was ascertained by administering the various products to guinea pigs _per os_.
_Symptoms._ In poisoning by _O. crocata_ the symptoms generally appear very quickly, and in serious cases death may follow in from one hour to a few hours. In Tutin’s experiments on guinea pigs the extracts referred to above rendered the animal hypersensitive in two to four hours, while marked convulsions, with trismus soon appeared; the heart-beat became very noticeably slow and the convulsions persisted until death ensued. There is great restlessness, difficult breathing, convulsions, loss of sensation, blindness and stupefaction (Müller); Lander says the symptoms recall hemlock poisoning, with the addition of green fœtid diarrhœa.