=Cinchona (Peruvian Bark).=—This is the bark of an evergreen tree growing in the tropics. It owes its medicinal properties to _quinin_ and _cinchonin_, especially the former. It is used as a general tonic, as a stomachic, as a febrifuge, and as an anti-malarial. Large doses cause ringing in the ears, headache, deafness, dimness of vision, convulsions, and coma. The _dose_ of _quinin_ and its salts is from 1 to 30 grains (0.06-2 gm.); of _cinchonin_, 1 to 30 grains (0.06-2 gm.); of the _Compound Tincture of Cinchona_ (Huxham’s Tincture), 1 to 4 drams (4-15 c.c.). =Cocain.=—This is the alkaloid of a shrub (_coca_) growing in South America. Applied to mucous membranes or raw surfaces, or injected under the skin, it blanches the part and produces anesthesia. Applied directly to the skin, however, it is without effect, as it is not absorbed from the unbroken skin. Internally, it is sometimes employed to stimulate the heart, to stimulate the respiration, and to allay vomiting. Its repeated use, even as a local remedy, is dangerous, in that it is prone to cause a habit, the symptoms of which are mental failure, loss of flesh and strength, anemia, and intense craving for the drug. The symptoms of acute cocain-poisoning are excitement, delirium, a rapid pulse, hurried breathing, convulsions, and coma. The _dose_ of _cocain_ is from ⅛ to ½ grain (0.008-0.03 gm.). As an anesthetic it is usually employed in from 2 to 4 per cent. solutions. A 2½-grain tablet of cocain, dissolved in a teaspoonful of water, makes a 2 per cent. solution; a 4½-grain tablet, in the same amount of water makes a 4 per cent. solution; a 10½-grain tablet in a like amount furnishes a 10 per cent. solution. These percentages are not mathematically correct, but are sufficiently exact for any surgical purposes. =Cod-liver Oil.=—This is more of a food than a medicine. It is preferable to other oils in being more readily digested. When well borne by the stomach, it is a valuable remedy in wasting diseases, especially phthisis. The _dose_ is from 1 to 4 drams (4-15 c.c.). It may be given in emulsion, in flexible capsules, or pure, dropped in the froth of porter. It is best taken two hours after meals.