164 INORGANIC AGENTS 



mouth lowered in resistance by elimination of mercury. Potassium iodide 

 is given to hasten the elimination of mercury from the body. 



The use of mercury, or any of its compounds, if continued for any 

 considerable time, either internally or externally, in such a way as to 

 lead to absorption, may cause a chronic form of poisoning or mercurialism. 

 This condition is characterized by fetor of the breath and soreness of the 

 gums, making mastication painful. The gums are swollen and bleed'eas- 

 ily; the tongue swells and salivation ensues. The teeth become loosened, 

 the salivary and parotid glands enlarge, the temperature is elevated, and 

 if the condition continues, there are: ulceration of the mouth (due to 

 irritation produced by mercury eliminated in the saliva), necrosis of the 

 jaw, general weakness, a watery condition of the blood, edema, anemia 

 and cachexia, prostration and death. Local poisoning, as exhibited by 

 paralysis of the hand and forearm, has occurred in a man who applied 

 the ointment of red iodide of mercury to cattle. There is a tendency for 

 mercury to accumulate in the liver and kidneys, chiefly, and also in the 

 tissues generally, when given in large doses, or in smaller doses when con- 

 tinued for a considerable period. 



The prevailing fashion of administering calomel in small and re- 

 peated doses may lead to mercurialism if purgation does not occur. 



Stomach and Intestines. — Calomel and preparations of metallic mer- 

 cury are most commonly used for their action on the digestive tract. It 

 has been shown by Schaefer (1910) that calomel is transformed in the 

 duodenum by the alkaline juices into a gray salt consisting of the car- 

 bonate and oxide. The cathartic action of calomel depends upon the gray 

 salt which is both locally irritating and antiseptic. The same change 

 occurs outside the body when calomel is added to a solution of sodium 

 carbonate. 



While calomel acts chiefly on the duodenum, sweeping out the bile, 

 it continues its action on the whole of the small intestine. If the dose 

 is insufficient to sweep out the whole intestinal tract it may empty the 

 contents of the small bowel into the colon, causing putrefaction there of 

 the undigested food. This is one of the reasons for following calomel 

 with a saline to flush out the large bowel. Calomel and mercuric chloride 

 are also intestinal antiseptics. 



The mercurial purges have always enjoyed a great reputation in the 

 treatment of so-called biliousness and torpid liver, the supposition being 

 that they stimulated the liver and flow of bile. But experiments on man 

 and animals show that they exert no apparent effect on the liver or 

 biliary secretion. Their indubitable efficacy is due to their cathartic and 

 intestinal antiseptic action, as such conditions (biliousness, etc.) are not 

 owing to liver disorder but to indigestion. 



The purga*^:ve action of calomel and mercury is assisted by salines 

 (as above), which increase the amount of fluid in the bowels, and aid in 

 the expulsion and prevent the absorption of mercury. The saline should 

 be given four hours after the administration of calomel to cattle. 



Blood and MetahoUsm.—li is stated that calomel may be absorbed 

 unchanged from the intestines by leukocytes to some extent. It is prob- 



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