MAGNESIUM tjgo 3. Caustic potash gives a white precipitate, soluble in excess, which reappears on adding ammonium chloride, but not on adding hydrogen sulphide. 4. Ammonium carbonate gives a white, fiocculent precipitate. 5. A blue incrustation is formed on charcoal when heated with a solution of cobalt nitrate. Medico-Legal Points.—Aluminium is present in many vegetables, in many fruits in milk, in eggs, and in sea food and probably in the tissues of the human and anirnal bodies. Aluminium vessels used for cooking purposes are regarded as quite harmless It is possible that slow poisoning may occur among almunium workers. A case?* is recorded in which a man working with the metal suffered from loss of memory tremors, jerky movements, impaired co-ordination, chronic constipation and incontinence of urine. MAGNESIUM Magnesium Sulphate (Epsom Salts), MgSO*, 7H2(X—This forms small colourless rhombic prisms, and dissolves readily in water. Its solution has a saline, bitter taste' and acts as a purgative. The pharmacopceial dose is 30 to 240 grains. When taken in excess, it acts as an irritant poison, It is contained in the official preparation of I^Tistura sennte composite (Black draught), dose, 1 to 2 fluid ounces and is an ingredient of mistura magnesii hydroxidi (Cream of magnesia), dose, 60 to 240 minims. Symptoms.—These commence in less than half-an-hour after swallowing a poisonous dose. They are burning pain in the stomach and intestines, nausea, vomiting, purging dilated pupils, paralysis of the lower limbs, tetanic spasms, suppression of urine, collapse and death from respiratory failure. Sometimes, after swallowing a large dose, the patient becomes pale, feels giddy- falls down and dies from syncope. A Christian boy,72 7 years old, was given in the earhr morning 2 ounces of magnesium sulphate as an aperient and had vomited it up. Ue ^ j again been given another dose of 2 ounces about 2 hours later and had again Vomited but one hour later he became unconscious and was removed to the J.J. Hospital, Bombav* where he was found unconscious and cyanosed with dilated pupils reacting sluggigjjy shallow respirations, and a feeble pulse. He died in less than an hour. A case occurred to Dr. Khambolja of Kander in which a woman, about 20 years old, felt giddy soon after swallowing a dose of 1J ounces of magnesium, sulphate in the morning of the first October 1948, became unconscious and died within two hours. The Chemical Analvser Bombay, detected magnesium sulphate in the viscera usually preserved for chemical analysis. When injected into the blood, magnesium sulphate depresses the heart, paralyses the central nervous system and causes death from paralysis of respiration. Fatal Dose.—One ounce has caused death, though the same quantity may be given as a purgative. Two ounces have caused the death of a boy, ten years old. Fatal Period.—Death occurs rapidly from a few minutes to two or three hours Death occurred in 60 hours in a case where 310 cc. of a 4 per cent solution of magne- sium sulphate had been injected subcutaneously.73 Treatment.—Empty the stomach; give stimulants and treat the symptoms. Subcu- taneous or intravenous administration of calcium salts has been recommended, as calcium salts have an antagonistic action on the inhibitory effect of magnesium sulphate. Post-mortem Appearances.—Signs of irritation of the gastro-intestinal tract may be present. .Chemical Tests.—1. A solution of sodium phosphate in the presence of ammonium chloride and ammonia gives a white, crystalline precipitate, soluble in dilute hydro- chloric acid. 2. Caustic potash gives a white precipitate. 3. A rosy pink incrustation on charcoal, if heated with cobalt nitrate. Medico-Legal Points.—Poisoning by magnesium sulphate is rare, but a few cases of accidental poisoning have occurred from large doses of magnesium sulphate taken as a purgative. Injected into the spinal canal magnesium sulphate induces ansesthesia, and alleviates tetanic spasms- Magnesium sulphate closely resembles oxalic acid and zinc sulphate; hence the latter salts have frequently been mistaken for the_ former. Magnesium sulphate is chiefly excreted in the urine, rendering it alkaline., 71. J. Spofforth, Lancet, 1921, Vol. I, p. 1301. 72. Bombay Chem. Analyser's Annual Heport, 1930, p. 4. 73. Curtis, Jour. Amer. Med. Assoc., 1921, Vol. 77, p. 1492.