630 THE POPULAR SCIENCE MONTHLY. 



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 pulmo- 

 nary diseases are actually unknown. Protracted cold weather thus 

 prevents epidemic catarrhs, but during the first thaw * Nature suc- 

 cumbs 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 stock- 

 ings 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 gen- 

 erally 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.) 



