POISONING BY ANNUAL MERCURY.
Annual mercury given in green fodder is stated to produce indigestion, diarrhœa, vesical and intestinal hæmorrhage, and early death. Some authors, however, deny that it has such toxic properties.
POISONING BY BRYONY.
In large doses all parts of the bryony plant are toxic—the root, stalk, and leaves.
Bryony is sometimes used as a purgative. Poisoning is characterised by nausea, sweating, diuresis, frequent action of the bowels, and, in grave cases, by tetaniform convulsions followed by death.
POISONING BY CASTOR OIL CAKE.
Causation. Excessive use of this form of cake is the usual cause of such poisoning, though bad quality is also an important factor. The castor oil beans are often insufficiently crushed and compressed, so that a considerable amount of oil is contained in the cakes as sold; but the most dangerous constituent is undoubtedly the material known as ricin, which, in some specimens of cake, may exist in highly dangerous quantity.
The oil contained in the cake, like every other fatty substance, favours intestinal peristalsis and the onward movement of the digested food. The laxative principle excites secretion, and if the cake be given for considerable periods, the most serious consequences may ensue.
Cakes prepared from mixed rape seed and castor beans act in a similar way, though in a longer or shorter time, according to their richness in ricin.
The earliest symptom consists in purgation, which gradually develops into super-purgation, and is followed by direct irritation of the mucous membrane, indicated by serous, fœtid, and sometimes sanguinolent, diarrhœa. The symptoms may appear in twenty-four hours. They are usually accompanied by a rise in temperature of 2° to 3° Fahr. Secretion of milk ceases, and animals heavy with young sometimes abort. In exceptional cases death follows.