318 MERCURY. 



uterine system leads to its employment as an emenagogue. Dif- 

 ferent obstinate cutaneous diseases, lepra, tinea capitis, scabies, 

 and others, are occasionally removed by the internal administration 

 of mercury as an alterative ; and these, as well as various forms of 

 cutaneous eruption and ulceration, often yield to the external 

 application of mercureal preparations. 



" The most important medicinal operation of mercury remains 

 to be stated — that displayed in removing the disease induced by the 

 syphilitic poison. Tn this its power is nearly, if not altogether* 

 specific ; no article in the materia medica can be substituted for 

 it ; and there may be affirmed of it, what cannot with equal justice 

 be said of any remedy employed in the treatment of any other 

 morbid affection, that, if duly administered, it will scarcely ever 

 fail in effecting a cure. It is difficult to assign any satisfactory 

 theory of its operation. Its efficacy has been ascribed to its 

 general evacuant power, in consequence of which the syphilitic 

 virus is discharged from the body. But the speedy disappearance 

 of the local symptoms of syphilis under its use, and even from its 

 local application, affords a proof that it operates on some other 

 principle ; no similar advantage is derived from any other evacuant ; 

 and its efficacy is not proportional to the evacuation it excites, but 

 is frequently displayed where this is altogether insensible. The 

 opinion has been advanced, that it acts as an antidote to the vene- 

 real virus, neutralizing it somewhat in the manner in which one 

 chemical agent subdues the properties of another — an opinion 

 extremely vague and hypothetical, and rendered improbable from 

 the consideration of the very small quantity of some of the more 

 active preparations of mercury, from which a cure may be obtained, 

 compared with the large quantity of others less active that require 

 to be administered. The explanation advanced by Mr. Hunter, 

 that the efficacy of mercury in the treatment of syphilis depends 

 on its general and permanent stimulant operation on the system, 

 by which it induces and keeps^up an action incompatible with that 

 morbid action which constitutes the disease, until the virus is 

 destroyed by the chemical changes going on in the system, or until 

 it is eliminated from the body by the usual excretions, is on the 

 whole most probable. 



