In the case which I have related, the influence of bad practice was palpable; but even here it was not so during all the time it was doing its deadly work, but only after that work was done. And in most cases in which bad treatment has been ruinous in its results, the evidence is not such, even at the conclusion of the case, as will satisfy the public, at least that portion of it which is inclined to quackery. An examination after death is not always obtained; and when it is, it will not always afford us as clear evidence, as was seen in the case above related, for both disease and medicine may destroy life, without leaving any manifest and undisputed traces of their action, to be revealed by the knife of the anatomist. If a lawyer make a mistake, for example in framing some instrument, it is readily seen to be a mistake, and definite and known results follow, clearly exposing his ignorance. But if a quack, or a physician, through mistake in the treatment of a case, destroy life, or fail to save it, when it could be saved by the use of proper means, we can very seldom have the opportunity of exposing such ignorance, because as you have seen in the chapter on the Uncertainty of Medicine, it is so difficult to connect effects in the human system indisputably with their cause. Suppose the fatal mistake is manifest to physicians, who happen to know the facts in the case; how can they demonstrate it to the satisfaction of the public? The only undoubted proofs of it are often buried with the patient; and if they are not, but are brought to light, even as clearly as in the case which I have described, the community do not adequately appreciate their value, as the honest and high-minded physician is often pained to find, in his conversations on this subject with even intelligent men. Many a popular and fashionable physician, as well as the quack, is saved by the causes to which I have alluded from any effectual exposure of his ignorance and unskillfulness. I have said that it is by no means easy to cull out from the mass of cases those in which the treatment must necessarily affect the question of life and death. There are inherent difficulties in the way of doing this. Even the skillful and careful observer may mistake in the attempt to do it, from the fact that the first appearance of a case does not always indicate the amount of disease, nor its obstinacy. While some cases, which appear of a grave character at the outset, turn out to be mild ones, when the disturbance of the attack is once over; those, on the other hand, which seem to be mild, are sometimes found to contain in concealment the elements of destruction. And if this difficulty seriously embarrass the physician in making the selection spoken of, much more then would it embarrass the community.