In short we are here in a region where exact scientific investigation has not yet established reliable criteria of judgment. We cannot cite irrefutable facts. We can only express opinions and opinions are usually grounded in prejudice. Physicians tend normally to prohibit, but they rarely prohibit judiciously because, under our present chaotic medical system, they cannot afford to make a sound, thorough-going clinical examination of every patient and must regard medicine as an art--_i. e._, fall back upon empiricism. As for prejudice, it amounts to little. Cromwell and his Puritans smoked excessively. About 1840 women smoked outrageous stogies and cumbersome pipes so shamelessly that men were alarmed and vigorous caricatures satirized them in the periodicals of the day. Early in the Victorian era smoking was all but a lost art. Today it is again in ascendency, yet human depravity has remained at about one level throughout. In an editorial upon the subject during 1925 _The Journal of the American Medical Association_ especially emphasized the fact that variations in human susceptibility and tolerance were factors as yet little understood. Extreme caution in generalization was wisely advised on such subjects as the harm inherent in tobacco smoking, and the reader was admonished that over-indulgence in turnips or parsnips, or even in water, would turn out a great deal worse than he might anticipate on immature consideration. This factor of human individualization is rightly coming to the front in medical literature today. Advances in biological chemistry constantly attest the fact that each human individual is unique chemically. What Smith can do with impunity Jones can only do with a prospect of sudden death. This is not a superficial matter, but one deep seated in the cellular structure of the human body, a thing going back through ages of inheritance via the complex and ill-understood chromosome. More and more it is being realized that routine diets, prescriptions and prohibitions will not do in all cases--in fact are actually unsafe and dangerous in many. For all we definitely know today with positive assurance we cannot deny the proposition that tobacco smoking is probably beneficial to many people. Not long ago everybody was urged to go in for bran because we all sadly needed roughage. Bran would cure constipation and a thousand routine diets spattered the press. It was all very well, except that constipation persisted. Today it is realized that nervous and psychic factors have much more to do with constipation than diet and the parade has set in that direction now. In fact some authorities declare that these rough diets have actually had fatal consequences in certain instances where a smooth diet was required.