CHRONIC ARSENICAL POISONING. 



This comes from continuous injudicious dosing with arsenic, or 

 from the condensing on the grass of the vapors from the smelting 

 of ores containing arsenic. 



Syiiiptonis. There is chronic indigestion, emaciation, hide- 

 bound, depilation, red or weeping eyes, chronic diarrhoea, sup- 

 pression of milk in cows, muscular weakness, paraplegia, soreness 

 of the gums, salivation. 



The lesions are essentially the same only less intense than in the 

 acute form. Hugo found in the intestines of poisoned animals a 

 slimy, serous, grayish white fluid, and a false membrane like a 

 frog spawn streaking the intestine. Later this may be dense like 

 a diphtheritic membrane. There was fatty degeneration of the 

 liver and of the gall bladder epithelium. Injection of the 

 capillary vessels of the brain and pia, and effusion into the 

 ventricles and on the surface of the brain were found in dogs. 



EliDiimxtion. Arsenic is eliminated mainly in the urine, but 

 also in part in the bile and perspiration. 



Tests for Arsenic. When taken in the solid form it may be 

 found undissolved on the gastric mucosa. 



If burned on red hot charcoal or iron it gives out the odor of 

 garlic. 



Marsh's test consists in evolving ar.seniureted hydrogen from 

 zinc and sulphuric acid to which a little of the suspected liquid 

 has been added. A flask is taken having a cork conveying two 

 tubes, one a funnel reaching nearly the bottom of the flask, and the 

 other a delivery tube of some length and provided with a chloride 

 of calcium bulb, and at its end turned up at right angles and drawn 

 out to form a narrow orifice. Pieces of zinc are placed in the 

 bottom of the flask, and sulphuric acid is poured upon these 

 through the funnel. This causes the evolution of hydrogen. 

 The suspected liquid is now added, and the gas issuing from 

 the delivery tube having been lighted, a piece of cold white 

 porcelain is held above and a short distance from the flame. A 

 dark metallic .spot of arsenic is obtained. The stain obtained by 

 antimony differs in being formed more closely to the flame, in 



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