Modern medicine owes its successes to centuries of trial-and-error experiments on the human body. Without accidental discoveries and meaningful mistakes, our medical canon wouldn’t be as full as it is today.
Here are a few of the grisly practices that led to the efficient methods we have today.
Trepanning, as the practice is called, is one of the oldest surgical practices in the archaeological record. Skulls with holes have been found dating back to the Neolithic period, according to a study in Surgical Neurology International.
The procedure was usually done on people who were acting abnormally. The belief was that drilling a hole into someone's head until the surface of the brain tissue showed could cure them of seizures or mental disorders.
According to Mental Floss, French neurologist Paul Broca suggested in the 1870s that the procedure had been done by ancient cultures to keep bad spirits from being trapped in the brain. But archaeologist Ephraim George Squier, who worked with Broca, suggested people trepanned to relieve swelling and pressure buildup in the skull after head injuries.
Today, the practice of trepanning still exists among brain surgeons, albeit not by the same name. They call it craniotomy, and it's used to relieve pressure in the skull and implant brain stimulators in Parkinson's patients.
The technique involves placing a heated cup on targeted areas of the body and inducing suction by cooling the cup or mechanically pumping out air. The cup is left on for five to 15 minutes, then taken off, leaving a visible mark that eventually fades away.
There are two ways to do cupping: dry cupping and wet cupping. The major difference between the two is that wet cupping involves small incisions on the skin to let blood flow during the process.
These bloodsucking worms might be the stuff of nightmares, but for a time, they were used unflinchingly in medicine.
The belief was that bodily fluids had to be in balance to be healthy; imbalances were considered the cause of inflammation, fever, or diseases that made skin appear redder than usual.
Leech saliva reportedly has anesthetic properties, which is why a leech can go unnoticed and is the reason the medical procedures were virtually painless for patients.
Today, we know that mercury is a toxic metal that can contaminate seafood and lead to numerous medical conditions. Organic mercury that accumulates in the body can cause blindness, memory loss, numbness, tremors, and even seizures and death.
In medial history, mercury was used until the late 20th century. Sometimes known as calomel, mercury chloride was used as a laxative, antiseptic, skin ointment, and diuretic, even though it had toxic concentrations that caused side effects when used over time.
The use of mercury has since dropped significantly -- we now have mercury-free thermometers and the US government has issued warnings about eating too much seafood, which can lead to mercury poisoning.
Historical medical drama 'The Knick' features Clive Owen as a surgeon with a nasty cocaine habit. In addition to shooting himself up, he also shoots his patients up -- a move that's historically accurate, since the drug was used as a local anesthetic.
The first use of cocaine as a surgical anesthetic was in 1884, when Austrian ophthalmologist Karl Koller used it to numb the eyes of one of his patients. The drug then proliferated on the market in the form of toothache drops, lozenges, and wines. Of course, it was also an ingredient in Coca Cola during those years.
Doctors and patients soon realised, however, that they were using dangerously high concentrations -- patients died or succumbed to addiction after taking too much cocaine.
In 1905, safer, weaker forms of the drug, like Novocaine, began to be developed.
Heroin was once used in cough medicine and marketed to children.
In 1897, Felix Hoffmann, an employee for pharmaceutical company Bayer, was instructed to make codeine (which is still widely used today as a cough suppressant). Instead, he accidentally synthesized diamorphine, the chemical name for heroin.
Hoffmann didn't anticipate the addictive effects of the drug. Between 1898 and 1910, diamorphine was marketed as 'heroin,' a supposedly non-addictive cough suppressant and morphine substitute.
Bayer continued to sell diamorphine, despite reports that suggested people had grown tolerant and addicted to the drug.
Though the reports surfaced as early as 1899, the drug wasn't banned until 1924.
Before antipsychotic medicines existed, doctors performed lobotomies on patients with psychological conditions and mental disorders. As many as 50,000 people received lobotomies, most of them between 1949-1952, according to NPR.
Dr. Walter Freeman, the neurologist who popularised the procedure in America (and became notorious for practicing it on cadavers with an ice pick) said it could cure schizophrenia, depression, and other mental illnesses.
The procedure involved sticking a slender, sharp instrument into the eye socket's tear duct until it hit bone. Once there, the doctor would hammer lightly until it broke through the part of the skull protecting the prefrontal cortex. The doctor would then twist the tool to clear the bone and destroy brain fibre in the area.
The practice was phased out thanks to antipsychotic drugs, but the Nobel Prize Committee hasn't rescinded the award it gave to Egal Nomiz, the original creator of the lobotomy.
The Ancient Egyptians put moldy bread in poultices to treat sores and infections. Records show that the Chinese also used moldy tofu to treat their wounds. Even though they didn't know what antibiotics were back then, they were on the right track.
Penicillium, the fuzzy blue mould you sometimes find on bread, is what the popular antibiotic penicillin comes from.
Penicillin was properly derived in 1929 by Scottish biologist Alexander Fleming, and production and demand for the antibiotic ramped up in the following decades. Without it, modern medicine could have turned out much differently.
NOW WATCH: Briefing videos
Business Insider Emails & Alerts
Site highlights each day to your inbox.