whole, be the less preposterous mistake; for it is true that long droughts, by parching out the swamps, may sometimes reduce the mosquito-plague, but no kind of warm weather will mitigate a catarrh, while the patient persists in doing what thousands never cease to do the year round, namely, to expose their lungs, night after night, to the vitiated, sickening atmosphere of an unventilated bedroom. "Colds" are, indeed, less frequent in midwinter than at the beginning of spring. Frost is such a powerful disinfectant that in very cold nights the lung-poisoning atmosphere of few houses can resist its purifying influence; in spite of padded doors, in spite of "weather-strips" and double windows, it reduces the in-door temperature enough to paralyze the floating disease-germs. The penetrative force of a polar night-frost exercises that function with such resistless vigor that it defies the preventive measures of human skill; and all Arctic travelers agree that among the natives of Iceland, Greenland, and Labrador pulmonary diseases are actually unknown. Protracted cold weather thus prevents epidemic catarrhs, but during the first thaw Nature succumbs to art: smoldering stove-fires add their fumes to the effluvia of the dormitory, tight-fitting doors and windows exclude the means of salvation: superstition triumphs; the lung-poison operates, and the next morning a snuffling, coughing, and red-nosed family discuss the cause of their affliction. "Taken cold"—that much they premise without debate. But where and when? Last evening, probably, when the warm south wind tempted them to open the window for a moment. Or "when those visitors kept chatting on the porch, and a drop of water from the thawing roof fell on my neck." Or else the boys caught it by playing in the garden and not changing their stockings when they came home. Resolved, that a person can not be too careful, as long as there is any snow on the ground. But even that explanation fails in spring; and, when the incubatory influence of the first moist heat is brought to bear on the lethargized catarrh-germs of a large city, a whole district-school is often turned into a snuffling-congress. The latter part of March is the season of epidemic colds.
The summer season, however, brings relief. In the sweltering summer nights of our large sea-board towns the outcry of instinct generally prevails against all arguments of superstition; parents know
- The correlation of damp weather and catarrhs can be explained by the fact that moisture lessens the modicum of fresh air which would otherwise penetrate a building in spite of closed windows. "All materials," says a correspondent of the "Revue des Deux Mondes," "become impermeable to the air when they are wet. It has been found less easy to drive moisture through bricks and mortar than to make air pass through them; only a few drops of the liquid can be made to appear on the opposite surface. Water is therefore not easy to dislodge from the pores it has occupied, and is removed at most very slowly by evaporation. But, when water stops the pores, it prevents the air from circulating through them a mischievous effect upon the permeability of building materials."—(Vide Popular Science Monthly" for December, 1883, p. 170.)