camping-gear for the Alleghany highlands, and arrange for their return by the end of October. Patrons of a transatlantic passenger line had better go a month sooner, to avoid the midsummer nightmares of a superheated cabin. European tourists can combine the useful with the agreeable by doing their sight-seeing afoot; but they should remember that Alpine morning breezes can not always neutralize the bedroom air of a South-German tavern, and that sultry heat aggravates the effects of mal-ventilation. The German, Austrian, and Russian shepherds stay the whole summer with their flocks, but, as a class, are nevertheless remarkably subject to pulmonary diseases, and for the following reason: They pass the night in a Schäfer-hütte, a sort of ambulance-box, eight feet by four, and six feet high, without windows, but with a tight-fitting sliding-door. This door the ill advised proprietor shuts after dark, and breathes all night the azotized air of his Black Hole of Calcutta on wheels. In the morning he awakens with a hacking cough, superadded to a profuse perspiration and a feeling of nausea. The air of the mountain meadows gradually relieves the other symptoms, but not the cough, which finally becomes chronic; and, with exquisite facilities for the attainment of a patriarchal longevity, the slave of the night-air superstition dies in the forenoon of his life.
Mal-nutrition, combined with a tubercular diathesis, hastens the macerative (or "hectic") stage of the disease. Air is gaseous food, and the body of an ill-fed man who stints his lungs in life-air is thus suffering under a compound system of starvation. Hence the occasional rapidity in the development of tubercular consumption, and its frightful ravages in the homes of the poor, and in the stuffy tenements of French dress-makers and Silesian weavers, where a perpetual air famine aggravates the want of bread.
Fat is the best lung-food, and, among all fat-containing substances, fresh, sweet cream is about the best, and salt pork the worst. There is a close correlation between consumption and the various scrofulous affections; "pulmonary scrofula" is, indeed, sometimes used as a synonym of tuberculosis. The French physiologist Villemin found
- "The rate of life, and consequently the amount of disintegration, in any organized structure, depend in great measure upon the temperature at which it is maintained; and thus it happens that the production of carbonic acid from this source, at the ordinary rate of vital activity, is much more rapid in warm-blooded than in cold-blooded animals, and that the former suffer far more speedily than the latter from the privation of air. But, when the temperature of the reptile is raised by external heat to the level of that of the mammal, its need for respiration increases, owing to the augmented waste of its tissues. When, on the other hand, the warm-blooded mammal is reduced, in the state of hibernation, to the level of the cold-blooded reptile, the waste of its tissues diminishes to such an extent as to require but a very small exertion of the respiratory process to get rid of the carbonic acid, which is one of its chief products. And, in those animals which are of retaining their vitality when they are frozen, vital activity and disintegration arc alike suspended, and consequently there is no carbonic acid to be set free" (Gurney Smith, "On Respiration").