The brain symptoms may cause death. As later symptoms of lead poisoning may be mentioned lead gout and kidney disease (lead nephritis). The genesis of both these diseases is much disputed. It seems to be proved that the gout is true gout (with presence of tophi) and that the contracted kidney is indistinguishable from ordinary chronic Bright’s disease. The kidney symptoms suggest that a regular excretion of lead through the urine takes place which, if it were a fact, would have been an important aid to diagnosis. But often analysis of urine for presence of lead is negative. Excretion of lead by the skin is scarcely to be credited, although occasionally affirmed. Elimination of lead is effected mainly through the intestines (probably for the most part as sulphide of lead). All lead compounds more or less are to be regarded as poisonous, although the intensity of the action depends on the amount absorbed. For this its solubility in water or in weak acids (hydrochloric acid of the gastric juice) is the simplest test. According to this acetate of lead, lead chloride, carbonate of lead (white lead), oxide of lead (lead dross), minium (red oxide of lead) are relatively the most poisonous. Lead sulphate and lead iodide are to be regarded as relatively less poisonous, although by no means innocuous. The least poisonous, if not altogether innocuous, is sulphide of lead, because it is an insoluble lead compound. Treatment of lead poisoning ought to aim first and foremost at the elimination of lead from the body. But unfortunately such attempts have had little success. Treatment of symptoms is all that for the most part is possible. Administration of iodide of potassium to assist the excretion of lead has not been found the success which many anticipated. This remedy however, can be tried; better results are to be expected from careful regulation of the bowels by means of purgatives. During colic administration of opium or morphia may be advisable to relieve pain and overcome the probable cramp of the intestinal muscles. The cautious administration of atropine (occasionally with cocaine) also serves the same purpose. Hot compresses and mustard plasters may be applied, and liquid diet should be given. Lead cachexia must be treated by strengthening diet. Electrical treatment for lead paralysis is advocated. From baths (sulphur baths) nothing more is to be expected than a bracing effect—elimination of lead through increased diaphoresis is hardly to be hoped for. ZINC (ZINC ALLOYS) Zinc (Zn) melts at 412° C. and distills at about 900° C.; exposed to the air it burns, when heated, into zinc oxide. Older writers, when investigating gastric and intestinal diseases and affections of the nervous system observed in zinc smelters, regarded them as the result of chronic zinc poisoning; but it may now be accepted as certain that these symptoms are due to the lead always present in the zinc.