Hair of the dog:
Today this phrase refers specifically to partaking of liquor after waking, in order to see off the ill effects of the previous night’s overindulgence – something that might well occur on a New Year’s morning. But originally “the hair of the dog that bit you” described a supposed medical treatment, based on an ancient belief that an injury from a dog bite could be treated with a dressing that included a few hairs from the offending animal.
A dose of radium:
The unfortunate scientists who discovered the radioactive element radium discovered too late that it was also deadly – in the meantime, the strangely glowing stuff was touted as a remedy for everything from arthritis to dental decay, in the form of radioactive bath salts, radioactive drinking water and even radioactive toothpaste. This phase of “radiation quackery” in the early 20th century ended quickly when many of its proponents died suddenly from radiation illnesses.
The tapeworm diet:
Intestinal tapeworms were touted in the early 20th Century as a sure-fire way to get rid of body fat and keep it off. Pills that claimed to contain tapeworm cysts were marketed in the US until around 1920, although no-one is now sure if they really did. Urban legend tells that the opera singer Maria Callas kept trim with tapeworm pills – but in fact she suffered from tapeworms after eating contaminated steak tartare, a dish made from raw meat.
Holes in your head:
The practice of trepanation, or having holes drilled your skull, has attracted a surprisingly large number of adherents over the centuries. Trepanated skulls have been found in prehistoric tombs from thousands of years ago, and in the Middle Ages it was touted as a cure for madness, epilepsy, migraines and various mental illnesses. Today this treatment has only limited medical use for some types of eye surgery.
Smoking cigarettes:
Before there were anti-smoking ads, there were pro-smoking ads. In the early 20th century it was common for cigarette advertising to tout the health benefits of smoking tobacco. The inhalation of fumes from burning tobacco was even suggested as a therapy for asthma and other lung disorders, and images of reassuring doctors were often used to sell cigarettes.