THALLIUM: 545 5. Lead is eliminated largely in the faeces, and to a small extent in the urine. It is also slowly excreted in the bile, saliva, milk, and hair. How- ever, being a cumulative poison, lead tends to accumulate in the system, Chuni Lai Bose15 reports that lead was detected in the urine of a man about six weeks after he was poisoned by white, lead taken in mistake for betel-lime. 6. Idiosyncrasy plays a great part in the effects of the poison. Some people, even though exposed to the action of lead salts, may not be affected. Persons addicted to alcohol are more prone to the attack of chronic poison- ing. Gouty persons are soon affected; it should, however, be remembered that chronic poisoning develops gout and granular kidneys. 7. Not only does abortion occur is a pregnant woman suffering from chronic lead poisoning usually between the 3rd and 6th months, but a healthy woman, if impregnated by a man suffering from chronic lead poisoning, is likely to abort. Children are more susceptible to lead poisoning than adults, the central nervous system is particularly susceptible in them. Children suffering from chronic lead poisoning are generally backward in their studies even after recovery, as their mental development is often affected. Infants may suffer from slow and progressive lead poisoning by imbibing lead secreted in the milk of their mothers who are poisoned by face powders, skin cosmetics and hair dyes containing lead. The other sources of poison- ing in infants are feeding bottles made of glass containing lead and lead nipple-shields. 8. Blair Bell, Williams and Cunningham16 have carried out investiga- tions on the toxic effects in the human subject of lead administered intravenously. The lead used was metallic lead in colloidal form for the treatment of malignant neoplasms. They have shown that there is great difference in individual tolerance to lead, and that the male is more tolerant than the female to the toxic effects of lead, as the following figures tend to demonstrate:— Maximum and Minimum amount of Lead required to produce Toxic Symptoms: Average for all ages Maximum Minimum Males Females Males Females 0.34 g. 0.29 g. 0.1 g. 0.04 g. THALLIUM Thallium is a soft, heavy metal, having a tin-white, lustrous colour, but, on exposure to the air, tarnishes upon its surface, owing to the formation of black thallous oxide. It is chiefly used in the dye and glass industries. The chief salts of thallium which are of value from a toxicological point of view are thallium acetate and thallium sulphate. Thallium acetate was used as a remedy for the night-sweats of phthisis, but is now used only as a depilatory in the treatment of ringworm .of the scalp. It is administered to children under ten years of age in the dose of 8 to 8,5 mg. per kilogramme of body weight. The hair of the head begins 15. 16. 35 Calcutta Med. Jour., Feb. 1916. Lancet, Oct. 17, 1925, p. 793.