in the loss of physical or muscular power of the body, the attenuation of muscular fiber, the loss of integrity of cell-structure, and consequent liability to the invasion of disease, rather than in actual stature of inch-measurement. The true causes of this deterioration are neither very obscure nor far to seek. They are bad air and bad habits. To these may be added a prolific factor operating largely to produce degeneration of race, and that is, frequent intermarriage, often necessitated by religious affinities.
Taking these causes in the order in which I have placed them, but without reference to their relative intensity, I think bad air is a potent factor of enfeeblement. Included in the phrase "bad air" are bad sanitation and overcrowding. I have no doubt in my mind that it has a powerful and never-ceasing action, paramount and decisive, on the physical frames of young and old town-dwellers, producing deterioration of physique, lowered vitality, and constitutional decay. For over thirty years I have been hammering away at this question of "bad air" and "bad sanitation" as the prime causes of impairment of health and race, and the more I consider it the more I am convinced of the soundness of my conclusions. A great deal has been said on this subject, and it is not difficult to adduce conclusive evidence from a large variety of reliable sources in proof of the deleterious effects of impure air on the animal economy. Consumption is the best type of degenerative action and loss of vital energy. It stands out in bold relief as the disease most rife wherever foul air exists. The significance and value of fresh air were recognized by the old fathers of medicine. Hippocrates was accustomed to advise a walk in fresh air of ten or fifteen miles daily. Aretseus, Celsus, and Pliny speak of the good effect of fresh air; and our great English physician, Sydenham, did the same thing. Dr. Guy found that of 104 compositors who worked in rooms of less than 500 cubic feet of air for each person, 12·5 per cent had had spitting of blood; of 115 in rooms of from 500 to 600 cubic feet, 4·35 per cent showed signs of consumption; and in 100 who worked in rooms of more than 600 cubic feet capacity, less than two per cent had spit blood. Consumption is only one of the long list of evils to which the town-dweller is exposed. But it is not desirable to particularize all the medical features of this question; their name is legion. It may be well to mention that the Labrador fishermen and the fishermen of the Hebrides, with plenty of fresh air, are practically exempt from this disease. The absence of pure air acts upon the animal economy in much the same way as the withdrawal of light on plants, the result being pallor and feebleness of constitutional vigor. This effect ramifies in every direction; the tissues of which the human body is composed lose their tonicity and contractile power, and even mental integrity may be more or less affected.