But, even previous to this, it might be made a question, how far what is here assumed as a fact is well founded? And if it should appear, that mercury does not cure _lues venerea_ in proportion to the evacuation which it produces, a strong argument might from thence be brought against this theory. But what may be said on this question will, with greater propriety, occur when the objections to the theory come to be adduced, than in attempting to refute and invalidate the arguments brought in its favour. At present, it will be sufficient to show, that, even allowing it to be true, it is no argument in favour of the supposition. If it be true, that mercury cures _lues venerea_ in proportion to the evacuation it produces, it may indeed, with some degree of probability, be concluded, that the evacuation and cure are not unconnected. And, if the evacuation is not the cause of the cure, it might at least from thence be inferred, that both of them depend upon the same cause; but it no more, unquestionably, follows from thence, that the evacuation is the cause of the cure, than that the cure produces the evacuation. The degree of evacuation which, in any case, arises from the employment of mercury, will, it is natural to imagine, be proportioned to the quantity of active mercury which is introduced into the system. But, in whatever way mercury acts in the cure of the venereal disease, it may then be supposed to act most powerfully when it is present in the system in most considerable quantity. In this point of view, then, the evacuation which arises from the use of mercury is to be considered merely as an index of the quantity of the medicine which is introduced into the system in an active state; and the cure may be proportioned to the evacuation, only as pointing out the degree in which the mercury exists in the habit. Even supposing, then, that the foundation upon which this argument is built were not to be called in question, yet, taken in its greatest latitude, it is still at best but doubtful; and from it no conclusion can be drawn in favour of the theory which it is brought to support. The second argument mentioned in proof of the supposition that mercury acts, in the cure of _lues venerea_, as an evacuant, was, that the cure produced by mercury depends more upon the stimulant power of the preparation employed, than upon the quantity of mercury which is used.