_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. In _cattle_, one hour after eating, there is depression and accelerated respiration; the conjunctivæ are injected, the eye turns in its orbit, the pulse is weak but rapid, and there is foaming. Later, there is colic, and spasmodic contractions of limbs and jaws. If the quantity ingested is sufficient to cause death, the animal falls, but still moves its limbs. There is bellowing, contraction of pupils, insensibility, and death in convulsions—or, if not fatal, cattle may remain paralysed. In the _horse_, the appearance of the symptoms and the course of the illness are much more rapid and the nervous symptoms are accentuated. If the _pig_ has consumed only a small quantity it soon gets rid of the poison by vomiting; but if the quantity is considerable there is no vomiting and death is as rapid as with cyanide poisoning (Cornevin). REFERENCES. 10, 14, 73, 81, 141, 146, 170, 190, 205, 209, 213, 235, 246.