=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. =The lesions= are those of hæmorrhagic enteritis. =Treatment= is principally of a preventive character. The cakes should be examined, and if they contain insufficiently crushed seeds or beans should be discontinued or given in smaller quantities. The proportion of ricin in mixed rape and castor cakes should be determined. Curative treatment consists in removing the cause and treating the enteritis. The latter is best controlled by giving emollients, diuretics, and mucilaginous drinks prepared from linseed, marsh-mallow, barley, etc. POISONING BY COTTON CAKE. Cotton cake forms a rich food, which fattens animals very rapidly, but given in excess may produce true poisoning, and if prepared from undecorticated seed may produce mechanical irritation ending in obstruction of the bowel. The latter accident occurs only in the sheep. It consists in obstruction of the omasum (œsophageal gutter), and particularly of the abomasum, by the woody seed covering, the fibres of which become agglutinated and close the pyloric opening, just as do the fragments of wool or the hairs in animals affected with the licking habit (pica, depraved appetite). The mass thus formed passes into the intestine, and is apt to become fixed at some point and to cause death. In the ox, as in the sheep, true poisoning may result from the action of an injurious principle which Cornevin discovered in the seed and particularly in the meal. The relative rarity of such accidents is explained by the composition of the cakes, which are rich in husks but poor in meal.