MINERAL OE INORGANIC POISONS 65 



The greater part of a dose of silver nitrate is thus 

 rendered unabsorbable, but in contact with organic matter 

 the chloride is reduced, and the silver converted into black 

 silver sulphide, which passes into the fseces. 



Nevertheless, some proportion is absorbed, and in the case 

 of prolonged dosage is deposited with blackening of the 

 skin, especially when exposed to light, in the condition 

 known as argyria. 



Silver is stored in the liver, spleen, pancreas, and bones, 

 and is mainly excreted through the bile. 



Toxic Doses. — Dogs are poisoned by from 30 to 60 

 grains of silver nitrate. The larger animals would doubtless 

 require doses of considerable magnitude, but data on the 

 point are wanting. 



Symptoms. — Large doses of silver nitrate cause the 

 symptoms of gastro - enteritis, with vomition of blood- 

 streaked clots in dogs. Great prostration is caused, with 

 weakening of the heart's action, and often paralysis, 

 convulsions, and death from shock. 



Chronic poisoning, argyria or argyrism is often attended 

 in animals by the same blackening of the skin as in man. 

 There is chronic indigestion, loss of appetite, weakness, 

 anaemia, and emaciation. 



Post-MoFtem Appearances. — Beyond the signs of gastro- 

 enteritis the lesions due to acute silver poisoning are not 

 characteristic. With large doses, and when vomition has 

 not been profuse, flakes of discoloured silver chloride might 

 be noticed. The bowel contents are black from the presence 

 of silver sulphide. 



In chronic poisoning there is fatty degeneration as witK 

 arsenic, antimony, and phosphorus. 



Treatment. — Sodium chloride is a chemical antidote to 

 acute silver poisoning, acting by formation of silver chloride^ 

 It must be remembered that silver chloride dissolves slightly 

 in salt solution, so the dose given should not be dispropor- 

 tionately large, and should be diluted. Demulcents and 

 opium should follow the ordinary measures to secure 



removal of the cause. 



5 



