Louis Pasteur’s famous experiments in the 1860s—including his swan-necked flasks, which demonstrated that microorganisms didn’t spontaneously generate in broth—convinced much of the scientific establishment that his germ theory of disease was correct. Pasteur was so successful, in fact, that he kicked off a craze for discovering the infectious agents behind all sorts of ailments. This zeal, though, caused some scientists to search for the microbial culprits behind conditions we now know have a more complex genesis—such as schizophrenia and other psychiatric illnesses.

Two such investigators—Bayard Holmes and Henry Cotton—firmly believed that the atypical behaviors and trouble with distinguishing reality that are characteristic of schizophrenia were caused by some kind of toxin. They hypothesized that the body itself produced this toxin and that it poisoned the brain.

Holmes and Cotton independently tried to cure schizophrenia by cutting out the organs they thought were responsible for the illness. Holmes focused on intestines; Cotton also removed "teeth, tonsils, gall bladders, cervices, colons, thyroids and other body parts," according to the Journal of Medical Biography.

The pseudonymous blogger Neuroskeptic tells the tale for Discover. He writes that both "surgeon-psychiatrists" were following the theory of autointoxication with their work:

This was the idea that ‘insanity’ was actually a state of chronic intoxication, caused by some mind-altering substance or toxin produced inside the sufferer’s own body. Proponents of the autointoxication theory didn’t all agree on what this natural hallucinogen was, or on where it came from. Some held that the toxin was generated by the human body’s own glands and organs, while others believed that it was produced by bacteria that had infected the host. Holmes and Cotton fell into the latter camp.

When his son developed schizophrenia, Holmes, who had never trained as a psychiatrist, "devoted the rest of his life to researching the disease." In 1916, he decided that the cause was a type of intestinal blockage produced by an overgrowth of bacteria. The bacteria themselves pumped out the toxin, which he thought was histamine.

His solution: cut open the intestine by going through the appendix and wash the intestine out daily. Tragically, when he performed this surgery on his son, Ralph died within four days, due to complications. Still, Holmes went forward with about 22 patients. Jonathan Davidson of Duke University, who wrote the journal article, reports that Holmes claimed several "good successes" and two fatalities. His son’s case he expunged from his medical reports.

Cotton’s success wasn’t better, though he did specialize in psychiatry after qualifying in medicine in 1899 in Maryland. He did an astonishing number of surgeries during his tenure as director of the Trenton State Hospital in New Jersey and claimed success rates over 80 percent and a mortality rate of 25 to 30 percent. This high death rate, he said, was "due to the poor physical condition of patients with chronic psychosis… at times Cotton operated in the absence of consent or in defiance of family wishes," writes Davidson.

The methods may seem brutal today, but in the context of the time, they could have seemed bold and visionary. (More modern treatments for mental illness, like shock therapy, don't have the best reputation, either, in retrospect.) And though the side effects of today's treatments are much less harsh than death, researchers are still far from understanding every aspect of this disease—or how to treat it.