Observations on the Operation and Use of Mercury in the Venereal Disease

by Andrew Duncan

To this argument, it may indeed occur as an objection, that mercury does not in every case, from topical application, produce a cure of venereal ulcers. This, it might be imagined, should happen, did it operate in the manner here alledged. But it is to be remembered, that the venereal virus may often be so situated, while it produces an external sore, as to be totally out of the reach of any application made to the surface of that sore. And, even in cases where the seat of the virus is superficial, the mercury may be applied in such a form as will not readily admit of a conjunction with the virus. Those cases, therefore, in which mercury has failed of producing a cure, can never afford any sufficient reason for setting aside this argument. But, on the other hand, any one well vouched instance, in which mercury, by being topically applied, has produced a cure in the manner here alledged, is a sufficient foundation, for every thing which has been advanced from this fact, to prove the supposition of its being an antidote to the venereal poison.

From what has been said, it appears, that mercury is an antidote to the venereal virus; and that, whether it be introduced into the circulating system, or used externally only, it comes in contact with the venereal virus in those parts in which it is lodged, previous to its producing a cure. It may, then, be reasonably concluded, that the theory formerly suggested is well founded; and that mercury cures lues venerea from its power as an antidote, in consequence of its being actually applied to the venereal matter.

In favour of this hypothesis, it may farther be urged, that it is confirmed by a proper attention to many phænomena attending the cure of lues venerea by mercury; while at the same time it is not equally liable to objection, as the other theories which have been mentioned.

From the supposition of a topical action in the manner here supposed, the fluid to be acted upon is, as it were, separate and distinct from the general mass. In this case, then, the objection, that the effects of the mercury will be taken off from the quantity of matter upon which it has to act, will not apply. At the same time there is here no necessity for having recourse to any hypothetical attraction between mercury and the venereal virus.

It cannot, indeed, be alledged, that, in this case more than in the former, any obvious change occurs in the appearance of the venereal matter in consequence of the use of mercury. But the venereal matter, even in the most detached state in which it ever exists in the human body, is always blended with a certain proportion of pus and other humours. From this circumstance, we can never become acquainted with what is its real appearance. It cannot, therefore, be reasonably expected, that any changes which take place in it should become the object of observation. But observation sufficiently demonstrates a manifest difference in the effects produced by this virus, after the use of mercury, when compared with those which that virus before produced. That, therefore, in consequence of the employment of mercury, its nature is in reality changed, is but a reasonable conclusion.

It was formerly adduced, as an argument in favour of another supposition, that the cure of lues venerea produced by mercury was proportioned to the quantity of discharge which the mercury occasions. This assertion we have already attempted to show is by no means, in every case, true. It must, however, be allowed, that in some cases it does hold, and in those cases more especially where the discharge takes place from the system in general. To account for this on the theory here advanced, it is only necessary to consider in what manner such a discharge arises from the internal use of mercury.

These evacuations are, without doubt, to be referred to the mercury reaching and acting upon the excretories by which they are made. The quantity of these discharges, then, will, in many cases, serve as a standard by which to determine the quantity of active mercury circulating in the system. But, in proportion to the quantity of mercury which circulates in the general mass of fluids, a greater or less quantity will come to be applied to every part in the body; and, among others, to those places in which the venereal matter exists. Upon the supposition, then, that mercury acts in the cure of lues venerea as an antidote, it is easy to see how the cure should, in such cases, come to be proportioned to the quantity of the discharge.

Mercury, as was already observed, does not always produce a cure from external application. Where this fails, the cure is often effected by internal use. Mercury, from being used internally, comes to be applied to parts otherwise inaccessible, and even to the interior surface of superficial sores, to which, from external application, it cannot penetrate. From this, it is obvious on what principles the internal use of mercury co-operates in the cure of lues venerea with external application; or produces a cure alone where it is not used externally at the same time.

Although the cure of lues venerea from mercury may often correspond with the quantity of the evacuation, yet it frequently happens, that, from the early increase of any one particular discharge, the cure is frustrated. This is particularly experienced in those patients in whom the almost immediate effect of mercury is to excite salivation. While this fact is a very strong objection against the supposition that mercury cures by operating as an evacuant, it can readily be accounted for upon the theory here adopted. In such habits, the quantity of mercury accumulated in the circulating fluids can never be very great, as it finds a ready outlet from the system.

Besides these phænomena, this theory affords a ready solution for many others also. From hence it is easy to account for the obstinacy of this disease after it has affected the bones. When that has happened, the application of mercury to the part affected, whether it be externally applied, or taken internally, can only be obtained after long continued use.