Another, after making a few inquiries, starts some supposition or theory, and this directs all his future inquiries. He of course obtains a very partial knowledge of the facts, and this is mingled with errors. And so it is with him in his investigation of medical subjects. He is a theorizing practitioner. Another makes many inquiries, but they are of a rambling character. He finds out many of the facts in regard to the article, but by no means all of them. His observation is active, but it is without method and incomplete. Though he will be diligent in the investigation of disease, and will appear to most persons to be an acute and skilful observer, he never will obtain a thorough and complete knowledge of any case. Another, by a natural succession of inquiries, discovers one fact after another, till he knows the whole. He does not ask a single irrelevant question. The answer to every question either developes a new fact, or confirms one already discovered. He separates accurately the probable from the true, wholly rejecting the merely plausible. He frames no theory. His search is only for facts. You may be sure that he will be a skilful observer in the sick room, and that in the investigation of disease he will be constantly adding to his store of valuable and well-arranged facts. Do you wish to ascertain what characterizes a physician’s _measures_ in the treatment of disease? Instead of watching his practice, of which, as you have seen, you cannot judge with any good degree of correctness, observe what measures he proposes when acting, not in the capacity of a physician, but in that of a citizen, a neighbor, a member of an association, and what reasons he gives for these measures. If you find that he advocates measures which show common sense, shrewdness, and good judgment, and which accomplish the purpose aimed at; you may safely conclude that the same common sense, shrewdness and good judgment mark his treatment of his patients, and that he is a skilful and successful practitioner of medicine. A very little thing will sometimes develope some characteristic of a physician’s measures. A physician, as he starts his horse to leave you after a pleasant chat, finds the rein caught under some part of the harness. He pulls it up to disengage it; but, as he does not succeed, he gives it a twitch in which he succeeds no better. His face reddens, and he twitches again and again, each time more violently, and finally, by tearing out a loop in his harness, he disengages the rein. You may safely infer that that physician will be apt to have just such twitching measures in his treatment of the sick, and will in this way mar some things which are of some more importance than the loops in his harness.