The dominant note of the discussion that for years has been waged in scientific and medical circles as to the effect of alcohol on the human constitution has been, to the puzzled layman at any rate, the insistent, reiterated cry of the fundamental “mystery” of alcohol. Alcohol is poison! cries one school. It is not anything of the sort, being, as a matter of fact, a food! retorts the opposing school. Its use in health or its administration to patients sick of any ailment is hardly short of a crime, declares one leading physician. Tut! tut! alcohol in moderation does no harm, and it is invaluable in the treatment of many diseases! replies another. And so the arguments proceeded. Summing up his views of the deliberations of the British Association for the Advancement of Science, recently held at Leicester, England, and which formed a storm center for the great alcohol debate, a noted chemist in London “Science,” said that we know how far the sun is, and can tell the weight of the earth, predict when the next comet may be expected, and give true answers to many other important questions, but we do not know “anything to speak of” on the subject of alcohol. As to the discussions that have waged at Leicester and elsewhere on the question of the medical use of alcohol, the general impression left on the world of laymen is that they all (the noted authorities) disagreed with one another more or less, and that nobody can declare with any scientific authority whether alcoholic liquor is good for us or bad for us. We propose here to describe the work of one scientist who has made experiments which enable him to declare with authority that alcohol is injurious. This investigator is Charles E. Stewart, M. D., of the Battle Creek Sanitarium. He has closely studied the work of Sir Edward Wright, London, the discoverer of “Opsonins”; and his experiments were suggested by those of Wright. They led him to the discovery that alcohol has a harmful effect on the blood by lowering its supply of opsonins. It has been demonstrated to the satisfaction of most students of Wright and Metchnikoff, and their allies, that the opsonins form one of the most valuable of the body’s defences against disease. And if Dr. Stewart has demonstrated that alcohol poisons the opsonins, it must be admitted that at last a positive and tangible proof has been brought forward of alcohol’s harmful qualities. What nourishes and strengthens the blood, helps the lifeforce within us; what weakens or poisons the blood, is an attack upon the very citadel of vitality. Alcohol, says Dr. Stewart, is such an enemy.