POISONING BY ZINC.
Sulphate and chloride poisonous, less potent oxide and carbonate. Symptoms: colics, emesis, congested alimentary mucosa, diarrhœa, cramps, weakness, paresis, anæmia, emaciation. Lesions: white, leathery, sloughing or ulcerated alimentary mucosa, strictures. Treatment: emesis, demulcents, tannic acid, sodium carbonate.
The sulphate and chloride are the most likely to be taken in dangerous amount, the former being mistaken for Glauber salts. Three ounces of sulphate intravenously in the horse has proved fatal, or 10 to 50 grains in the dog. In the vicinity of zinc ore furnaces the agent is taken in on the fodder as oxide or carbonate.
Symptoms. There is much abdominal pain, emesis in vomiting animals, quick pulse, congested mucosæ, diarrhœa, cramps, weakness, and paresis, and if the patient survives, anæmia and emaciation.
Lesions. The mucosa of mouth, gullet, stomach and perhaps duodenum is white, opaque, hard, corrugated, leathery, sloughing, or ulcerated. Congestion is well marked. Strictures may appear in chronic cases.
Treatment. Give tepid water and tickle the fauces. Use white of egg or milk freely and mucilaginous agents. Tannic acid, or carbonate of soda are antidotal by tending to precipitate insoluble compounds.
POISONING BY SILVER.
Toxic doses of silver come mostly from materials used in the arts. The photographer uses chiefly the nitrate, iodide, bromide, cyanide and chloride. Taken into the stomach the silver salts are less poisonous because they are largely precipitated as insoluble chloride or albuminate. The chloride and albuminate are, however, soluble in solutions of alkaline chlorides and hence even they may poison.
Symptoms. Colic, emesis in vomiting animals the vomited matters blackening in the light, diarrhœa, great muscular weakness, paresis, weak clonic spasms, and disturbed respiration. The nervous symptoms are very prominent (Rouget and Curci). Chronic poisoning produces emaciation and fatty degeneration of liver, kidneys and muscles (Bogoslowsky).
Lesions. Patches of congestion and of white corrosion on the buccal œsophageal and gastric mucous membrane, the presence of the curdy white chloride of silver adherent to the gastric mucosa. In chronic cases the visible mucosæ and white skin may have a slaty color.