GENERAL ACTION OF MERCURY AND ITS SALTS 211 



PREPARATION. 



Vnguentum Hydrargyri Ammoniati. Ointment of Ammoniated Mer- 

 cury. (U. S. & B. P.) 



Synonym..— White precipitate ointment. Ammoniated mercury, 10- 

 benzoinated.lard. 90. (U. S. P.) 



GENERAL ACTION OF MERCURY AND ITS SALTS. 



External. — The salts of mercury are antiseptic, germi- 

 cidal, irritant and — in the ease of the soluble salts — caustic, 

 when applied to raw surfaces or mucous membranes. Cor- 

 rosive sublimate is one of the most powerful and frequently 

 used antiseptics. The germicidal action of mercury salts is 

 due to their habit of combining with albumin wherever it 

 exists and forming the albuminate of mercury. Thus they 

 act on bacteria and in so doing destroy germ life. The 

 caustic action of the soluble salts of mercury may be ex- 

 plained by the fact that when the salts are dissociated by con- 

 tact with the tissues the metallic and acid ions are corrosive. 

 Moreover, like the other salts of the heavy metals, they pre- 

 cipitate the proteids of the tissues with which they come in 

 contact but, unlike them, the mercury albuminate thus formed 

 is soluble to some extent in the fluids of the body and there- 

 fore does not protect the surface from the further action of 

 the salt. The antiseptic efl^ect of corrosive sublimate is les- 

 sened by this action since the salt is decomposed in contact 

 with albumin and the coagulated proteid prevents it from 

 reaching germs. By the addition of salt, hydrochloric or 

 tartaric acid to solutions of corrosive sublimate the union 

 of mercury with albumin. is materially prevented and such 

 combination (with tartaric acid) is provided in the tablets 

 sold for surgical purposes. 



Corrosive sublimate is more irritant to the tissues than 

 carbolic acid, creolin or lysol, and cannot penetrate raw 

 surfaces so well to reach germs (on account of its coagulating 

 proteids), and cannot be used in contact with metallic in- 

 struments since mercury is deposited upon them through 

 decomposition of this salt. The salts of mercury kill the 

 lower forms of animal as well as vegetable life, and are 

 valuable in the treatment of parasitic skin diseases. As a 

 rule, antiseptics relieve itching, and the mercury salts are 



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