Advice about sex has been around forever, some for better and some for worse. In the Victorian age (1837-1901), publicly available advice on sex was often wound up with the ideas of sin and public decency and control of one's animal nature. A list of 11 bits of Victorian advice on sex starts with these gems:
1. Be aware that sex makes you stupid.
Knowledge workers of the world be warned: “The accumulated evidence of the world goes to show that celibacy is a most favorable state for severe mental labor,” according to Eliza Bisbee Duffey.
Though radically progressive on many matters, Duffey held to the ancient notion that sex wasted the body’s vital spirits. She therefore recommended abstinence, by which “the forces of the body are conserved, and are concentrated, and that goes to brain-power which would otherwise be exhausted in sexual union.”
2. Too much hair makes you horny.
Large buns coiled atop the head were all the rage in the 1880s, much to the chagrin of Dr. John Cowan. “This great pressure of hair on the small brain produces great heat in the part,” he warned, increasing blood flow to the brain’s sex center and causing “a chronic desire for its sexual exercise.”
As you may guess, sex within marriage was okay, as long as one didn't engage in it too much. Read the rest of the list of Victorian sex tips at Mental Floss.