=Carbolic Acid.=—Externally, this acid is used in weak solutions (1 : 40 to 1 : 20) as an antiseptic, and in concentrated form as a caustic. Weak solutions are also employed to allay itching in skin diseases. Internally, carbolic acid is used as an antiseptic in dyspepsia and diarrhea. Applications of carbolic acid, even when dilute, should never be prolonged, as they are liable to cause gangrene. Poisoning by carbolic acid is characterized by white patches on the lips, the odor of the drug on the breath, burning pain in the abdomen, vomiting, purging, unconsciousness, and collapse. The _dose_ is from ½ to 3 minims (0.03-0.2 c.c.). =Castor Oil.=—This is an oil expressed from the seed of an East Indian plant. The seeds themselves are acrid poisons. It is a mild purgative, unloading the bowels very thoroughly in from four to six hours. It may be given in flexible capsules, in emulsion, or with equal parts of lemon-juice and glycerin. The _dose_ is from ½ to 1 ounce (15-30 c.c.). There are two simple methods of taking castor oil without producing nauseating effects. Have the patient wash out the mouth with water as hot as can be borne, then swallow the oil, and follow this by rinsing out the mouth well with hot water. The other method is to hold a piece of ice in the mouth long enough to chill the lining membrane, swallow the oil, and rinse the mouth with ice-water. =Chloral.=—This substance is an active depressant of the brain and spinal cord. In large doses it also depresses the heart and respiration. It is employed to produce sleep and to check convulsions. The _dose_ is from 10 to 30 grains (0.6-2 gm.) in some agreeable syrup. Poisonous doses cause unconsciousness, embarrassed breathing, and collapse. =Chloralamid.=—This is a comparatively safe and reliable hypnotic, producing sleep without causing much depression of the heart or disagreeable after-effects. The _dose_ is from 10 to 30 grains (0.6-2 gm.), well diluted. Hot liquids decompose it. =Chloroform.=—This substance is employed by inhalation as a general anesthetic, by the mouth as a sedative in colic, neuralgia of the stomach, and obstinate cough, and externally in the form of liniment as a counterirritant in muscular rheumatism, sprains, etc. As a general anesthetic it is more powerful than ether, more readily inhaled, but not so safe. Death from chloroform is usually the result of heart failure. The _dose_ of _Spirit of Chloroform_ (Spiritus Chloroformi) is from 5 to 30 minims (0.3-2 c.c.); of _Chloroform-water_ (Aqua Chloroformi), 1 to 8 drams (4-30 c.c.).