A couple of hundred years ago, doctors discovered a horrifying -and possibly fatal- medical disorder caused by "abuse of the genitals." They called it spermatorrhoea, which means involuntary ejaculation. France's preeminent physician of the time, Claude François Lallemand, wrote about the disorder in the 1830s.
During a period of fourteen years, I have collected more than one hundred and fifty cases in which involuntary seminal discharges were sufficiently serious to disorder the health of the patients considerably, and even sometimes, to cause death.
You know that today this would be called "nocturnal emission" or more colloquially "wet dream," which is correlated somewhat with masturbation, but neither is considered harmful. However, in the early 19th century, young men died of all kinds of unknown causes. If he was known to suffer from spermatorrhoea, it could easily be blamed for his death. But rather than studying the reason behind the, uh, event, doctors tried ways to keep it from happening, such as the invention detailed above. It delivered a small electric shock at the first hint of an erection, which woke the patient up and saved him from a wet dream. And it's not the most horrifying device invented to combat spermatorrhoea, which you can see and read about at Thomas Morris. -via Strange Company