Stratton claimed to experience mind-bending perception disruption, resulting in what he described as an "out-of-body experience" whenever his sight did not match up with his sense of feeling. After the experiment ended, he began to see the world "normally" again, although his definition of normality is obviously not ours.
Too Many Scientists Have Eaten Shit
Back in the early 20th century, the skin disease Pellagra ravaged the Southern states of the U.S. as effectively as deep-frying and racism combined. It was similar to leprosy, causing sufferers' skin to flake off and bleed, with a side of diarrhea and dementia for kicks. Its fatality rate was about 40 percent, and by 1912, South Carolina had reported 30,000 cases. So the government tasked Joseph Goldberger with finding out why all these people were turning into grayscale cases.
The first thing Goldberger noticed was that prisoners seemed to be especially susceptible to the disease, but prison staff were not, which seemed to contradict the popular idea that it was caused by a virus or bacteria. After ruling out biological class warfare, he concluded that some sort of dietary deficiency was the culprit. He of course then developed a methodical study of the prisoners' diet to determine what was lacking.
Just kidding, he ate their various excretions.
How this was supposed to diagnose a dietary deficiency isn't clear, but as always, we suspect it was secretly a messed up sex thing. Especially since his wife begged to get in on it. She described the time they spent eating the feces, snot, skin lesions, scabs, and urine of the prisoners (during what they called "filth parties") as the time in their marriage when they were the closest. Certainly, debilitating bloating and diarrhea -- which was the result of their experiments -- will do that for a relationship. Alas, they failed to contract pellagra, proving that it wasn't transmitted by bodily fluids at all. Turns out it was a lack of niacin, as confirmed by other people doing normal science.
Yellow fever's symptoms include fever (right there in the name), headache, chills, bleeding from the eyes and mouth, skin blisters, black vomit, and other things not usually seen outside of an Exorcist movie. Some scientists of the time believed the disease wasn't contagious, among them Jean Louis Genevieve Guyon. Because things were done hard back in the day, Guyon took a sweaty shirt from a man who had died of yellow fever and wore it for 24 hours. Then he injected himself in both arms with pus from the dead man's blisters. A few weeks after that, infuriated by his good health, Guyon donned the clothes of a patient so recently dead that they were still warm from the man's body heat (and still soaked in his vomit). When that was still not enough to sicken him, he climbed into the man's poop-filled bed, rolled around in it, and smeared it all over his body. He stayed like that for six and a half hours (because seven is obviously when that starts to get weird). And after all that, it was reported that "M. Guyon enjoyed uninterrupted health during the performance of these experiments." Presumably that refers only to the physical and not mental side of things.