east or west, the death-rate from lung-diseases was found to bear an exact proportion to the percentage of the inhabitants habitually engaged in sedentary and in-door occupations. Towns suffer more than the rural districts, cities more than country towns, manufacturing cities more than commercial and semi-agricultural cities, weaver-towns more than foundry-towns. "If a perfectly sound man is imprisoned for life," says Baron d'Arblay, the Belgian philanthropist, "his lungs, as a rule, will first show symptoms of disease, and shorten his misery by a hectic decline, unless he should commit suicide."
Moreover, it was shown that in non-manufacturing (uncivilized or pastoral) regions a low temperature seems to afford a protection against pulmonary disorders. Professor Jacoud found that, at an elevation of four thousand feet, the cold Alpine districts of Northern Savoy are almost free from lung-diseases. The medical statistics of the Austrian army have established the fact that recruits from the Tyrol, from Carinthia, and the Carpathians (Transylvania), i. e., from the highest, and consequently the coldest, provinces of the empire, enjoy a remarkable immunity from tubercular consumption. Dr. Hjaltelin, a resident of Iceland, states that among the inhabitants of that country pulmonary diseases are almost unknown.
But in the temperate zone consumption-statistics alone would enable us to infer the amount of dust-breathing and in-door work incidental to the pursuit of each trade. In the Italian cities that have largely engaged in the production of textile fabrics, consumption has become as frequent as in Lancashire. Irrespective of race-differences and special dietetic habits, the habitual breathing of vitiated air leads to the development of pulmonary scrofula. And science has furnished the rationale of that result. Physiology has demonstrated that air is gaseous food, and respiration a process of digestion. The atmosphere furnishes the raw material of the pulmonary pabulum; at each inspiration the organism of the lungs imbibes the oxygenous or nutritive principle of the air-draught, and excretes the indigestible elements. By breathing the same air over and over again, the atmospheric aliment becomes azotized, i. e., depleted of its life-sustaining principle, and therefore unfit to supply the wants of the animal economy. The continued inhalation of such vitiated air fills the respiratory organs with indigestible elements, which gradually accumulate beyond the dislodging ability of the vital forces, and at last corrupt the tissue of the congested organ and favor the development of parasites. Consumption is one of the diseases that seem to confirm the tenets of the germ-theory. A tubercular diathesis is favored by stagnant impurities of the circulatory system, by a warm and humid climate, and counteracted by cold air and other antiseptics. Six years ago a German physician demonstrated that the progress of pulmonary scrofula can be arrested by a pectoral injection of carbolic acid; and one of his countrymen lately ascertained that the tubercle-virus is alive with micro-
