LESIONS AND ANTIDOTES 277 



organs of the body affords the only positive proof of arsenical 

 poisoning. 



In treating acute cases of poisoning, the stomach must be 

 washed out with copious draughts of tepid water, and 

 emptied, in carnivora by emetics, such as mustard or zinc 

 sulphate, in horses or cattle by the stomach pump. The 

 best chemical antidote is prepared by precipitating ferric 

 chloride solution with ammonia, washing the precipitate with 

 warm water, and administering it moist and freshly made. 

 Some authorities recommend precipitation of two to three 

 ounces of liquor ferri perchloridi, with one ounce of sodium 

 carbonate diluted with water ; these quantities, freshly pre- 

 pared, suffice to neutralise ten grains of arsenic, converting 

 it into insoluble iron arsenite. Dialysed iron is nearly as 

 effectual as the ferric oxide or carbonate. These iron antidotes 

 should be given as soon as possible, in repeated doses, at 

 intervals of ten minutes, until a quantity at least twelve 

 times greater than that of the poison has been swallowed. 

 Magnesia in its hydrated or gelatinous form, prepared by 

 precipitating a solution of Epsom salt with caustic potash, 

 also greatly diminishes the solubility of arsenic. Perhaps 

 the best agent is made by adding magnesia to iron sulphate, 

 for this contains the iron hydrate and magnesium sulphate 

 which helps excretion. Insoluble powders, charcoal and 

 clay, envelop the particles of poison, and retard absorption ; 

 but such agents to be of service must be given before, along 

 with, or immediately after the poison. Oils, lard, glycerin, 

 mucilage, lime-water, white of egg, and milk, exercise 

 similar mechanical effect, and some of these bodies also 

 slightly diminish the solubility of arsenic. Demulcents and 

 opium are given to combat gastro-intestinal irritation, whilst 

 collapse is prevented by warmth and stimulants, alcohol, 

 digitalis and strychnine. In chronic cases oleaginous 

 laxatives and enemata relieve griping and constipation ; 

 easily-digested, nutritive food helps to sustain the powers of 

 life, and occasional diuretics hasten excretion of the poison 

 by the kidneys. 



MEDICINAL USES. Arsenic is administered to animals as 

 a gastric stimulant in dyspepsia and gastralgia, and in 

 chronic catarrhal diarrhoea, where imperfectly-digested food 



