It is also important to emphasize the fact that no hard and fast line of demarcation can be drawn between the bodily and mental effects of smoke-clouds or smoke-produced weather states. The human organism is a psycho-biological unity, and we cannot, except in a purely artificial and arbitrary fashion, divide the _soma_ and the _psyche_ into two independent compartments. Bodily states normally influence mental states and mental states, in turn, normally influence bodily processes, particularly the functions of the glandular, circulatory, sexual and neural systems. I. The Pathology of Smoke THE DIRECT AND INDIRECT EFFECTS OF SMOKE ON BODILY AND MENTAL WELL-BEING. _A. The direct effects of smoke on health and conduct._ When it is remembered that the average adult consumes about 30 cubic inches of air in each inhalation or possibly 864,000 cubic inches every day, it does not seem an exaggeration to say that more persons are devitalized, disabled and poisoned by the impurities contained in smoke-polluted air, than by the noxious ingredients in food and water. Not only do the solid and vaporous ingredients of smoke-begrimed air--noxious compounds of carbon, sulphur, nitrogen, chlorine, and arsenic--irritate the sensitive membranes of the eyes, nose, throat and lungs, and thus aggravate or cause inflammatory diseases of these organs, or produce collapse of their sensitive tissues, or increase their susceptibility to such specific diseases as bronchitis, pneumonia and subacute forms of phthisis; but the poisonous compounds also enter the gastro-intestinal tract, and this causes nausea, vomiting, diarrhea and systemic poisoning. That the gastro-intestinal tract is affected by inhaled solids has been demonstrated by the experiments of Saito (19)[1] on dogs and rabbits which were compelled to inhale, during periods varying from 1 to 33 hours, air charged with white lead dust. Only from 4 to 24% of the dust was subsequently recovered from the respiratory organs while the remainder was found in the digestive organs. In the case of a man who inhaled the air from 10 to 15 minutes on 20 occasions and who avoided acts of swallowing, 95% of the dust remained in the body, 50% of which was primarily retained in the nares. By processes of exclusion 12% probably found its way to the lungs, for 60 to 80% was recovered from the alimentary canal. Thus the principal portal of entry of soluble inhaled dust appears to be the alimentary canal.