Says Professor Alonzo Clark, M.D., of the New York College of Physicians and Surgeons: "All of our curative agents are poisons, and as a consequence, every dose diminishes the patient's vitality." Says Professor Joseph M. Smith, M.D., of the same school: "All medicines which enter the circulation poison the blood in the same manner as do the poisons that produce disease." Says Professor St. John, of the New York Medical College : "All medicines are poisonous." Says Professor B. R. Peaslee, MD., of the same school: "The administration of powerful medicines is the most fruitful cause of derangements of the digestion." Says Professor H. G. Cox, M.D., of the same school: "The fewer remedies you employ in any disease, the better for your patients." Says Professor E. H. Davis, M.D., of the New York Medical College: "The modus operandi of medicines is still a very obscure subject. We know that they operate, but exactly how they operate is entirely unknown." Says Professor J. W. Carson, M.D., of the New York University Medical School: "We do not know whether our patients recover because we give medicines, or because Nature cures them." Says Professor E. S. Carr, of the same school: "All drugs are more or less adulterated; and as not more than one physician in a hundred has sufficient knowledge in chemistry to detect impurities, the physician seldom knows just how much of a remedy he is prescribing." The authors disagree in many things; but all concur in the fact that medicines produce diseases; that their effects are wholly uncertain, and that we know nothing whatever of their modus operandi. But now comes in the testimony of the venerable Professor Joseph M. Smith, M.D., who says: "Drugs do not cure diseases; disease is always cured by the vis medicatrix naturae." And Professor Clark further complicates the problem before us by declaring that, "Physicians have hurried thousands to their graves who would have recovered if left to Nature." And again: "In scarlet fever you have nothing to do but to rely on the vis medicatrix naturae." Says Professor Gross: "Of the essence of disease very little is known; indeed, nothing at all." And says Professor George B. Wood, M.D., of Jefferson Medical College, Philadelphia ("Wood's Practice of Medicine"): "Efforts have been made to reach the elements of disease; but not very successfully; because we have not yet learned the essential nature of the healthy actions, and cannot understand their derangements." On the other side of the Atlantic the claims of the existing medical schools to popular favor, do not appear to rest upon any surer basis than they do here, if we may judge from the following opinions expressed by some of the most eminent authorities in the British Kingdom: "The medical practice of our days is, at the best, a most uncertain and unsatisfactory system; it has neither philosophy nor common sense to commend it to confidence." DR. EVANS, Fellow of the Royal College, London.