SILVER NITRATE 249 



given to dogs cause prostration, weakness of heart action, 

 intestinal irritation, and sometimes convulsions, paralysis, 

 and death from shock. When administered for some time 

 it is deposited in the skin and blackens it (' argyria '), and 

 has also been detected in the liver, spleen, pancreas, and 

 bones. As in the case of arsenic, antimony, or phos- 

 phorus, chronic poisoning is accompanied by fatty degenera- 

 tion. Rosenstern, experimenting on the vessels of the 

 mesentery of frogs, with weak solutions of various astrin- 

 gents, found silver nitrate most powerful ; lead acetate 

 followed next in order, requiring for production of a given 

 effect a solution five times as strong ; ferric chloride acted 

 only feebly ; alum caused dilatation. Silver nitrate is 

 slowly excreted in the albuminous secretions and in the 

 bile, mainly by the bowels, very little, if any, by the kidneys. 

 Undue irritation, produced whether internally or externally, 

 is diminished by solution of common salt, which forms the 

 insoluble and inert chloride ; milk and eggs should also be 

 given. For pigmentation there is no certain remedy, 

 although potassium iodide may be tried. 



MEDICINAL USES. As a tonic it is prescribed in chronic 

 nervous diseases, especially amongst dogs. Like arsenic, 

 it is sometimes used to check chronic gastric irritation. 

 Alone, or in combination with opium, it is given as an 

 astringent in chronic diarrhoea and dysentery in dogs ; 

 while enemata of 2 to 5 grains to the ounce of distilled 

 water or of starch gruel are occasionally also used. 



Applied to irritable, relaxed, discharging skin or mucous 

 surfaces, it coagulates mucus and albumin, eonstringes 

 dilated vessels, produces a white film of chloride, which 

 quickly deepens in colour, from the reduction of the 

 salt to the sulphide and metal. The solid nitrate or 

 strong solution rubbed into the skin raises blisters. The 

 eschar remaining, after a free dressing, gradually cracks and 

 peels off, leaving usually a healthy surface beneath. The 

 solid nitrate acting superficially, and readily localised, is for 

 many purposes preferable to fluid caustics, or to the delique- 

 scent caustic potash. It is serviceable for destroying ring- 

 worm, warts, and other neoplasms, and checking the progress 

 of indolent boils. Silver nitrate rolled in a piece of tissue 



