If you’re a millennial like me, you remember the Nickelodeon show Are You Afraid of the Dark?, in which kids sit around a campfire (or flickering stage lights or whatever), taking turns giving each other anxiety disorders with scary stories. The title is a bit of a silly question, though. Everyone is to some degree afraid of the dark, because we’re evolutionarily programmed to be. During our tribal days, in the blackness—where our dull senses were essentially useless—we were easy prey for hunters of the night. Safety was with our people in a fire-lit camp.

When civilization progressed and we settled into homes, that fear stuck with us. And then it gave rise to one of the stranger and more little-known theories of Western society: Night air is poisonous.

Not only was venturing into the darkness and breathing in the evening ether terrible for your health, but so too was simply leaving a window open at night. It was such a powerful and pervasive myth that all the way into the early 1900s, many anxious Americans were taking every possible measure to seal their homes against the poisons of the evening, according to Peter Baldwin in his essay “How Night Air Became Good Air.”

But good lord, how did it come to this? Being afraid to venture out into the night and mingle with mountain lions and such is one thing, but fearing the air you require to live? It turns out that our ancestors actually did have good reason to be afraid of night air—but not for the reasons they imagined.

The myth is a component of miasma theory, which held that “bad air” emanating from decaying organic matter caused disease (an idea later replaced by germ theory). This was particularly bad around swamps, of course, and seemed to worsen at night. Said Catharine Beecher, the great American educator: “Thus it appears, that the atmosphere of the day is much more healthful than that of the night, especially out of doors.”

In arguing against the silliness of "bad air," Ben Franklin proved that he really liked air—more so than most people. Wikimedia

The idea of bad night air had come over with the first Americans. Baldwin notes a conversation between none other than John Adams and Benjamin Franklin, who while traveling in 1776 were forced one night to share a room in a crowded inn. “The Window was open, and I, who was an invalid and afraid of the Air in the night (blowing upon me), shut it close,” Adams wrote in his autobiography. But old Ben Franklin demurred, demanding that he reopen the window, lie down, and listen to why he was being a jackass. So Adams endured the lecture until he fell asleep.

Adams was a highly educated man who would later become president, who nevertheless believed that when the sun went down air suddenly turned into poison. This was not, therefore, simply superstition. Indeed, over the next century and a half, even doctors and other educated folk propagated the myth.

For instance, Baldwin notes that in 1850 a prominent Cincinnati physician wrote that we ought to close up our windows when we turn in for the night. “Two effects result from" open windows, he claimed, "first, the exclusion of malaria [from the Italian meaning “bad air,” not the mosquito-borne disease], or the poison which produces autumnal fever; second, the exclusion of moisture, which in the latter part of the night, often chills the body.”

All along, though, there were dissenters. A dozen years after that doctor’s order, one skeptic admonished his fellow Americans who sealed their homes before retiring to bed: “The object of people generally appears to be to shut out the pure air of heaven—the breath of life—from bed-chambers, under the mistaken notion that night air is injurious.”

Cholera, as represented by a skeleton of "bad air." Wikimedia

There was, of course, the added benefit of not freezing half to death by closing windows. Northeasterners in particular had long suffered brutal winters, so when building practices improved and they were gradually gifted with better insulation, they jumped at the opportunity to hermetically seal their homes. And their fellow countrymen in the South, who had been absolutely terrorized by all manner of insects, were more than happy to do the same.

But with this came the decidedly first-world problem of stuffiness—and an entirely new dimension to the problem of poisonous air. With central air conditioning a long ways off, sealed homes essentially became tombs and, some experts warned, a health hazard. These advocates of ventilation, Baldwin writes, argued that those obsessed with shutting out the night air entirely “forced themselves to breathe air that was far more dangerous.”

You see, simply by exhaling we sullied the air in our homes. In their 1869 housekeeping guide The American Woman’s Home, Catharine Beecher (the aforementioned educator) and Harriet Beecher Stowe (author of Uncle Tom’s Cabin) argued in no uncertain terms: “Experiments seem to prove that other matter thrown out of the body, through the lungs and skin, is as truly excrement and in a state of decay as that ejected from the bowels, and as poisonous to the animal system.”

When in Doubt, Blame the Poor!

So it seemed when it came to opening up your windows at night, it was damned if you do, damned if you don’t. But for advocates of ventilation, Baldwin writes, it was civilization itself that was part of the problem, and “the worst danger was thought to come from crowded urban slums,” which gave off clouds of toxic air. Thus did the well-off in the mid-1800s begin seeing the home as “a refuge from the world, and the preferred middle-class neighborhood was at a distance from the tenement districts.” Ah, villainization of the poor. A tale as old as time.

But out in the sticks, where there were no slums to worry about, for many the principal concern remained bad night air—even all the way up to 1918, Baldwin notes, when one textbook told of some city folk recently visiting relatives in the country, only to find all of the windows in their bedroom nailed shut. It was a bit of an overreaction, sure, but these superstitious homeowners had indeed protected themselves from what had been the problem all along: mosquitoes.

The mosquito is both the most annoying and the deadliest creature on Earth, thanks to the malaria it carries. James Gathany/CDC via Wikimedia

It was never some mysterious evil of night air flowing into your home that brought sickness, but the insects that rode in on those drafts. Beginning in the late 1890s, according to Baldwin, we began to make the connection between mosquitoes and diseases like malaria and yellow fever. And so the homemaker’s defenses shifted to not only barricade their domicile with screens—now that they knew that it wasn’t simply air that was the problem—but to deploy all manner of wacky anti-mosquito powders and pastes, none of which were in any way effective.

Then the anti-mosquito campaign embraced the preemptive strike, championed by an entomologist named L. O. Howard. He urged towns to drain marshy ground and, no joke, dump kerosene in any standing water: cisterns, privies, and of course ponds. Baldwin notes that “Winchester, Virginia, was one of Howard’s early success stories: An anti-mosquito campaign there spurred so many townspeople to apply kerosene that ‘the town smelled like a Standard Oil tank.’” And at the risk of blowing the entire town two miles into the sky, mosquito populations plummeted.

Today we take a decidedly more measured approach to controlling mosquitoes, the deadliest critters on Earth, but that isn’t to say we aren’t getting creative with it. Some dude did, after all, invented a laser that blasts the bugs right out of the air. So with any luck, we’ll be able to get the better of the mosquito—without having to nail our windows shut or turn our ponds into lakes of fire.

Reference:

Baldwin, P. (2003) How Night Air Became Good Air. Environmental History. Vol. 8, No. 3, pp. 412-429