GENERAL ACTION OF MERCURY AND ITS SALTS 197 

 GENERAL ACTION OF MERCURY AND ITS SALTS. 



External. — The salts of mercury are germicidal, irritant, 

 and, in some cases, caustic, when applied externally. 

 Corrosive sublimate is the most powerful antiseptic in 

 general use. It unites with albuminous fluids in, or on, the 

 tissues, to form insoluble albuminates of mercury, and its 

 antiseptic properties are then lost. This action is prevented 

 by adding 5 parts of tartaric acid to 1 part of corrosive 

 sublimate, and such combination is provided in the tablets 

 foanufactured for surgical purposes. 



Hydrochloric acid, or salt, may be employed to obtain 

 the same result. Corrosive sublimate is a more powerful 

 germicide than carbolic acid, yet it cannot be used to disin- 

 fect metallic instruments, as the bichloride is decomposed 

 and mercury deposited upon them. 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 

 often used to comVjat this condition. Mercury and its salts 

 are absorbed when rubbed into the unbroken skin, particu- 

 larly when in combination with oil or grease. 



Metallic mercury and its salts (notably the iodide), when 

 rubbed well into the skin with fat, are thought to aid the 

 absorption of inflammatory exudates in underlying parts. . 



Internal. — The irritant salts of mercury, as the bichloride, 

 iodide, nitrate, and some of the oxides, in large doses, 

 produce gastro-enteritis, vomiting, colic, bloody diarrhoea, 

 collapse and death. The white of egg is an antidote to 

 corrosive sublimate, forming an insoluble albuminate. 

 Emetics, or the stomach pump, should be used in case 

 vomiting is not spontaneous. 



The use of mercury, or any of its compounds, if con- 

 tinued for any considerable time, either internally or exter- 

 nally, 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 



