No kind of reasoning ought to have weight, when opposed by fair experience. But physicians have formed contrary and opposite conclusions, with respect to the effect of the natural and artificial balsams, even when they have laid all theory and reasoning aside, and decided on their powers from practice and experiment only. This is sufficient to prove, at least, that their efficacy is very problematical. For my own part, after the fairest trials, and the most accurate observations I have been able to make, I cannot say that I ever knew them of service in any hectic complaint proceeding from an ulcer in the lungs; and I have generally found those physicians, on whose judgment I have more reliance than on my own, of the same opinion. It is far from being uncommon to see a cure retarded, not to say any thing stronger, by the means employed to hasten it; and physicians who found their practice on theoretical reasonings, are not the only persons to whom this misfortune may happen. Those who profess to take experience for their sole guide, if it is not directed by candour, and enlightened by natural sagacity, are liable to the same. A man may, for twenty years, order a medicine, which has in every instance done a little harm, though not always so much as to prevent nature from removing the complaint at last; and if the reputation of this medicine should ever be attacked, he may bring his twenty years experience in support of it. It ought to be remembered, that as often as the animal constitution is put out of order, by accident or distemper, nature endeavours to restore health. Happily she has many resources, and various methods of accomplishing her purpose; and very often she succeeds best without medical assistance. But medical assistance being given, she frequently succeeds _notwithstanding_; and it sometimes happens, that both physician and patient are convinced, that the means which did not prevent have actually performed the cure.