640 MEDICAL JURISPRUDENCE Fatal Dose.—Two to four fluid drachms, when taken internally, are likely to cause intoxication. One fluid ounce may prove fatal to an adult, although larger quantities can "be borne by individuals accustomed to its use. The concentration of ether necessary to produce anaesthesia reasonably quickly is about 6 per cent by volume or 15 per cent by weight in the inspired air. The concentration of ether reaching 0.14 per cent in the blood i^s sufficient to cause anaesthesia. When the concentration of ether reaches 11 per cent by volume in the inspired air, there is a distinct danger to life. The inhalation of two-and-a-half ounces of ether has caused death.28 Fatal Period.—Death may occur at any time during ether administration, or it may occur from pulmonary complications hours or days after recovery from ether anaesthesia. Treatment—Lavage of the stomach and cardiac and respiratory stimu- lants are indicated, if ether has been swallowed. Fresh air, respiratory stimulants, such as ammonia, artificial respiration, inhalation of oxygen com- bined with carbon dioxide, and strychnine hypodermically are indicated in cases where respiration or the heart's action stops during ether anaesthesia. Sodium amytal and glucose in saline may be administered to control the convulsions. Post-mortem Appearances.—The brain is pinker than normal and is slightly oedematous. The strong smell of ether is noticed on opening the thoracic cavity. The trachea contains a little frothy mucus. The lungs are congested, and exude a good deal of cedematous fluid smelling strongly of ether. Medico-Legal Points.—Accidental poisoning occurs from ether employed as an anaesthetic for general surgery. Ether is sometimes swallowed or inhaled for suicidal purposes. It is rarely used for homicidal purposes. Ether is excreted largely through the lungs and partly through the kidneys. ETHYL CHLORIDE, C,HBC1 This is prepared by wanning a saturated solution of hydrochloric acid in ethyl alcohol in the presence of anhydrous zinc chloride. It occurs as a gas at the ordinary temperature and pressure, but is usually condensed into a colourless, mobile, inflammable and volatile liquid, possessing a pleasant, ethereal odour and a burning taste. It boils at 12.5 °C. It is a pharmacopoeia! preparation, known as Aethylis chloridum, the non- official dose being 45 to 75 minims by inhalation for adults and 15 to 45 minims by inhalation for children. When used as a spray, ethyl chloride freezes the skin and surrounding tissues owing to its rapid volatility, and produces local anaesthesia for minor surgical work. Its pro- longed use may cause local sloughing of the tissues. It is administered by inhalation as a general anaesthetic for performing operations of short duration. It is sometimes used to induce anaesthesia previous to the administration of ether or chloroform. Ethyl chloride causes poisonous symptoms, when it' is inhaled in the concentrated form, It depresses the central nervous system and the respiratory centre, and produces myocardial weakness. A man, aged 40 years, with a diseased heart died after 90 drops of ethyl chloride had been inhaled.29 Treatment.—Stop the inhalation of the drug, and hold weak ammonia vapours to the nostrils. Keep the patient warm and start artificial respiration, if necessary. Re- covery is usually rapid. J Post-mortem Appearances.—These are not characteristic. The blood is fluid and the organs are congested. Ethyl Bromide, CoHsBr.—This is prepared by adding anhydrous sodium bromide to a cold mixture containing absolute alcohol and concentrated sulphuric acid and then distilling slowly. It is a colourless, volatile liquid, having an ethereal odour and a 28. Holland, Med. Chem. and Toxic., Ed. V, p. 406 CMrurgie> Leipzig> Jul^ 30> 1921» P- 1073; Jour. Amer, Med.