198 SODIUM CHLORIDE 



other sodium salts are removed from the body in unusual 

 amount, and most animals then instinctively take salt freely. 

 Besides furnishing an essential constituent of the animal 

 fluids and solids, it appears to assist in the assimilation of 

 nutritive matters. On the absorption of calcium salts it has 

 a marked effect, for when withheld from dogs with fractured 

 limbs repair and union are tardy. It is excreted by the 

 kidneys, skin, and mucous membranes. 



In common with cathartic salines, it acts chiefly physically 

 by osmosis, though it is absorbed much more readily and is 

 therefore a less effective purgative than magnesium sulphate. 

 It impedes absorption of fluid from the bowels, which thus 

 become mechanically distended with fluid. Their contents 

 are softened and peristalsis is encouraged. The blood not 

 only does not obtain from the bowels its usual supply of 

 fluid, but pours serous secretion into the bowels. Within an 

 hour or two after administration of a saline cathartic the 

 blood becomes concentrated, and thereafter gradually 

 recoups itself from the tissues, thus promoting excretion of 

 fluid and waste materials. 



On horses the cathartic action of common salt is uncertain, 

 often violent, and usually accompanied by considerable 

 irritation of the kidneys. On dogs it usually operates both 

 as an emetic and cathartic. Small and freely diluted doses 

 increase the secretion of urine and the proportion of urinary 

 solids. On pigs it acts as a purgative, but is not so safe or 

 certain as oil, jalap and calomel, or aloes. 



Toxic EFFECTS. Cases are recorded of pigs eating about four 

 and a half ounces daily for several days. They suffered from 

 flatulence, diarrhoea, vertigo, convulsions, and paralysis, and 

 died in eight to twenty-four hours after showing those symp- 

 toms. The mucous membrane of the stomach and bowels was 

 found after death highly injected and inflamed. Sir Charles 

 Cameron reported the poisoning of thirty-one pigs conveyed 

 by rail in a salt-truck, from the sides of which they had 

 licked the salt. For many hours they had been deprived of 

 water. They appeared in a state of asphyxia ; emetics and 

 subsequently stimulants were ordered, and eleven recovered. 

 The carcases of those that died exhibited ' signs of gastro- 

 intestinal inflammation ; the brain was greatly congested, 



