CHLOROFORM

also called trichloromethane nonflammable, clear, colourless, mobile, heavy liquid with a pleasant, etherlike odour, used as a solvent and an anesthetic. It was first prepared in 1831. The Scottish physician Sir James Simpson of Edinburgh was the first to use it as an anesthetic, in 1847, and it was generally accepted by 1853, when an English physician, John Snow, gave it to Queen Victoria during the birth of Prince Leopold, her eighth child. Chloroform is one of the most potent inhalation anesthetics, a few millilitres usually being enough to produce surgical anesthesia within a few minutes. It is mainly excreted with the exhaled air, and the patient awakens in 10-15 minutes, usually groggy but with very little nausea or vomiting. The margin of safety in chloroform use is relatively narrow. It has a depressing effect on most organs, especially the heart, blood vessels, liver, pancreas, and kidneys. Fatalities occurring during induction of anesthesia, termed primary collapse, are most often due to overdosage. Delayed chloroform poisoning results when chloroform is given in high concentration with too little oxygen and occurs most often in poorly nourished patients. Chloroform is often the preferred anesthetic in very hot climates because of its high boiling point, in very cold climates because of its high potency, and in the presence of flames and high-voltage electricity and under other conditions in which explosive anesthetics would be too dangerous to use. Chloroform is sometimes used internally as a pain reliever, for gas relief, and in cough medicines. Externally, it is used in solutions, ointments, or liniments as a local irritant or counterirritant for treatment of rheumatic conditions, headache, and neuralgia. It is an anti-itching agent for insect bites and in industry has a limited use as a solvent for fats. The specific gravity of chloroform is 1.476 at 20 C (68 F). The vapour is about four times as dense as air. Chloroform solidifies at -62 C (-80 F) and boils at 61 C (142 F). Its solubility in water is low (1 millilitre in 140 at 20 C) but high in animal and vegetable fats, alcohol, ether, acetone, gasoline, and most other organic solvents. Chloroform can be prepared from various organic compounds (most often from alcohol or acetone). Although it is not flammable, it may be decomposed to toxic compounds when exposed to flame, heat, light, or oxygen. The chemical formula is CHCl3.