But the proof of this antidotal power to the venereal virus in mercury, need not be rested upon a mere possibility. That mercury, in reality, does possess a power of destroying the activity of this poison, is rendered, if not certain, at least highly probable, from the circumstance of its curing venereal ulcers in consequence of topical application. In daily practice, we have undeniable proof, that mercury, topically applied, does cure venereal ulcers. This holds not only of those ulcers to which dressings can be applied, and continued for a considerable length of time, but of others also more out of reach, where its application can only be temporary. The advantages obtained from the different modes of applying mercury to ulcers in the throat, whether in the form of steam or gargle, sufficiently shew the truth of this assertion. The cure produced in all the cases of ulcers to which mercury is topically applied, is unquestionably to be referred to an immediate action upon the part. It takes place without any marks of the mercury having entered the system. And it can by no means be alledged, that, in such cases, any general affection, such, for example, as an increased discharge, is produced. But it is perhaps needless to insist on this, as in those instances the cure is never attributed to any other mode of operation than that of immediate action. As far, then, as the assertion, that mercury cures ulcers from topical application, can prove any thing in favour of its possessing an antidotal power, it may be assumed as an undeniable fact. It has indeed been alledged, that the cure here arising from the topical application of mercury, is entirely to be referred to its action as a stimulus to those parts to which it is applied. But this is an opinion, which, for many reasons, can by no means be admitted. Other stimuli which operate more immediately and more strongly, have by no means an equal effect. When mercury stimulates in the highest degree, the best consequences are by no means observed to arise from it. And it often produces a cure from topical application, where no effects of its operating as a stimulus can be observed. From these facts, it is evident, that the cure of venereal ulcers, produced by the topical application of mercury, can by no means be referred to its stimulant power. This naturally leads us to ascribe it to some other cause.