John Adams had a lot to worry about in 1776, what with fighting the revolutionary war, founding a country, and hating Thomas Jefferson. Despite all the real and genuine perils he faced, though, he managed to find the time to worry about something else altogether: the night air.
To wit: One evening in September 1776, Adams and Benjamin Franklin were forced to share a tiny room at a crowded inn in New Jersey. You’d think they’d be tired, having just won the war and all. But Adams couldn’t sleep.
“The window was open and I, who was an invalid, and afraid of the air in the night, shut it close.” (“Invalid” is no exaggeration: According to historian Jay Winik, Adams suffered from “constant headaches, fatigues, chest pains, visual impairment, night sweats, insomnia, heart palpitations, ‘quivering fingers,’ pyorrhea, skin eruptions and aching joints, memory loss and acute anxiety, melancholy, colds so severe that he thought had yellow fever, possibly a goiter, and perhaps even Graves’ disease.” Oh, and near-fatal toxothyrosis. And bad vision.) Anyway, Benjamin Franklin tried to reassure poor Adams that night air was nothing to be afraid of. But apparently his harangue was so boring that Adams fell asleep, never fully disabused of this particular fear.
Adams was no outlier on this. Over the next few centuries, this fear gained ground, as people embraced zymotic theory—in which poisonous vapors supposedly emanated from the ground (particularly at night…for some reason) and spread diseases like malaria. Belief in the deathly threat of the night air became commonplace, as Wired‘s Matt Simon explains:
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.”
So what caused people to stop holding their breath when it was dark outside? The realization that
mosquitos transmitted malaria made people stop demonizing the sky and start hating asshole insects like they should have all along. Understanding bacteria helped, too. Good one, science.