Emetics are medicines given for the purpose of causing vomiting, as in cases of poisoning. They consist of ipecacuanha, camomile, antimony, copper, zinc, and several others.
730. Ipecacuanha is an emetic, diaphoretic, and expectorant. It is used internally to excite vomiting, in doses of from ten to twenty grains of the powder, or one to one and a half ounce of the infusion, every half hour until vomiting takes place. To make it act well and easily, the patient should drink half pints of warm water after each dose of the infusion. As a diaphoretic, it should be given in doses of three grains, mixed with some soft substance, such as crumbs of bread, and repeated every four hours. Dose of the wine, from twenty minims to one drachm as a diaphoretic, and from one drachm to one and a half ounces as an emetic. Caution.--Do not give more than the doses named above, because, although a safe emetic, yet it is an acrid narcotic poison.
731. Mustard is too well known to require describing. It is an emetic, diuretic, stimulant, and rubefacient. It is used externally as a poultice. Mustard poultices are made of the powder, bread crumbs, and water; or of one part of mustard to two of flour; or, especially for children, of linseed meal, mixed with a little of the powder, or having some of the powder slightly sprinkled on the surface. Sometimes a little vinegar is added under the idea that it increases the strength of the poultice, but this is not necessary. In all cases where a stimulant is required, such as sore throats, rheumatic pains in the joints, cholera, cramps in the extremities, diarrhœa, and many other diseases. When applied it should not be left on too long, as it is apt to cause ulceration of the part. From ten to thirty minutes is quite long enough. When used internally as an emetic, a large teaspoonful mixed with a tumbler of warm water generally operates quickly and safely, frequently when other emetics have failed. In dropsy it is sometimes given in the form of whey, which is made by boiling half an ounce of the bruised seeds in a pint of milk, and straining off the curd. From three to four ounces of this is to be taken for a dose three times a day.