I found this story from following @HistoryWeird on Twitter. Their post is here. The original source, which has a title almost good enough for its own post, was Philip Thicknesse's The Valetudinarians Bath Guide, or the Means of Obtaining Long Life and Health, London, 1780.
"Philip Thicknesse (1719-92) was a writer for London’s Gentleman’s Magazine, known for his esoteric and eccentric views." In his above book, he gave a (ludicrous) theory about how to obtain a long and active life. That theory? A sort of sexual/spiritual vampirism. He writes that you can stay young forever(ish) by:
“…partaking the breath of young virgins, or what is perhaps the same thing, by partaking the breath of youthful persons.”
His justification? By "citing several examples of teachers who had lived to very old age. A schoolmaster named Claudius Hermippus, Thicknesse claims, lived to the age of 115 years and five days because he was:
'“…a tutor or director of a college of young virgins, where there might be a constant and quick succession of female children, from the age of five to 13. Doctors Busby, Friend, Nicholls and many learned men who have been at the head of great schools have all lived to a considerable age.'"
Of all the creepy things I have posted on this blog, this is definitely in the top ten. It's very, "Hey, baby baby, come sidle up next to grandpa. No, of course I'm not perving, I just want you to breathe on me. It's 'medicine'". Actually, appropriately enough for Halloween, this story is the non-family friendly version of Hocus Pocus.