In the cure of diseases by refrigeration, cold air is the readiest substitute for cold water. In the higher latitudes Nature supplies the remedy free of cost for six months of each year, and intermittently hundreds of times even in midsummer and at the threshold of the tropics, for the reduction of temperature in the early morning hours generally suffices to restore the functional vigor of the jaded organism.

The remedial effect of cold air equals that of cold water; air-cures, indeed, offer the advantage of superior facility of application for the cure of respiratory disorders. Expurgative currents of cold air can be made to reach the tissue of the lungs, and the significance of that circumstance is commensurate with the prevalence of a delusion more mischievous than the drug-superstition, vis.: the current theories concerning the cause of catarrh and consumption.

Consumption," says an advocate of medical reform, "is a house-disease, and the plan of confining its victim in overheated, ill-ventilated sickrooms favors the development of its germs to a degree which the remedial powers of Nature strive in vain to counteract. . . . Not drugs or warmth, but cold, pure air is Nature's specific for the cure of consumption and ' colds.'"

That "colds," or catarrhal affections, are so very common—so much, indeed, as to be considerably more frequent than all other diseases taken together—is mainly due to the fact that the cause of no other disorder of the human organism is so generally misunderstood. Few persons have recognized the origin of yellow fever; about the primary cause of asthma we are yet all in the dark; but in regard to "colds" alone the prevailing misconception of the truth has reached the degree of mistaking the cause for a cure, and the most effective cure for the cause of the disease. If we inquire after that cause, ninety-nine patients out of a hundred, and at least nine out of ten physicians, would answer: "Cold weather," "raw March winds," or "cold draughts"—in other words, outdoor air of a low temperature. If we inquire after the best cure, the answer would be, "Warmth and protection against cold draughts"—i. e., warm, stagnant, indoor air.

And yet it can be proved with as absolute certainly as any physiological fact admits of being proved, that warm, vitiated indoor air is the cause, and cold outdoor air the best cure of lung-disorders. Many people "catch cold" every month in the year, and often two or three times a month. Very few get off with less than three colds a year; so that an annual average of five catarrhs would probably be an under-estimate. For the United States alone that would give us a yearly aggregate of three hundred and fifty-five million "colds."

That such facilities for investigation have failed to correct the errors of our exegetical theory is surely a striking proof how exclusively our dealings with disease have been limited to the endeavor of suppressing the symptoms, instead of ascertaining and removing the cause. For, as a test of our unbiased faculty of observation, the degree of that failure would lead to rather unpronounceable conclusions. What should we think of the scientific acumen of a traveler who, after a careful examination of the available evidence, should persist in maintaining that mosquitoes are engendered by frost and exterminated by sunshine?

Yet, if his attention had been chiefly devoted to the comparative study of mosquito ointments and mosquito bars, he might, for the rest, have been misled by such circumstances as the fact that gnats abound near the icy shores of Hudson Bay and are rarely seen on the sunny prairies of Southern Texas.

In all the civilized countries of the colder latitudes, catarrhs are frequent in winter and early spring, and less frequent in midsummer: hence, the inference that catarrhs are caused by cold weather and can be cured by warm air.

Yet of the two fallacies, the mosquito theory would, on the whole, be the less preposterous mis' take, 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 indoor 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 catarrh; but during the first thaw Nature succumbs to art; smouldering 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 suffering, coughing, and red-nosed family discuss the cause of their affliction. "Taken cold"—that much they premise, without a 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 cannot 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 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 catarrhs, and the evil is ascribed to "dampness," when the cold-theory becomes at last too evidently preposterous.

To an unprejudiced observer that theory, though, is equally untenable in the coldest months of the year. No man can freeze himself into a catarrh. Out-of-doors we cannot "catch cold."

I have, upon the approach of cold weather, removed my undergarments," says Dr. Charles Page, "and have then attended to my outdoor affairs, minus the overcoat habitually worn; I have slept in winter in a current blowing directly about my head and shoulders; upon going to bed, I have sat in a strong current, entirely nude, for a quarter of an hour, on a very damp, cold night, in the fall of the year. These and similar experiments I have made repeatedly, and have never been able to catch cold. I became cold, sometimes quite cold, and became warm again, that is all. ("Natural Cure," p. 40.)