Google Samuel Hahnemann,
he invented Homeophatic medicine 1790 (!). He was NOT using scientific methods and made crazy claims even scientists back then found nonsensical and distanced themselves from him. It's 100% pure quackery based on his personal hunch on this self experience:
"While translating William Cullen's Lectures on the Materia medica into German, Hahnemann began to doubt Cullen's theory about Cinchona bark, a Peruvian plant that is now the basis of the malaria cure quinine, so he launched his own experiments, using himself as a guinea pig. Taking large doses of the substance, Hahnemann developed the fever, chills, thirst, and throbbing headache that characterize malaria. This experience convinced Hahnemann that small doses of the same substance would prompt the body's own immune system to fight off the disease, in much the same way a flu shot carrying deactivated germs wards off the flu. This became Hahnemann's famous maxim, like cures like, or the Law of Similars.
Read more at http://biography.yourdictionary.com/samuel-hahnemann#hDs1J7YfwGpCHk3U.99"
That was 1790! Medicine was just guesswork. For example he had no idea that white blood cells even exist because leukocytes where discovered 50 years later. So a guy who doesn't even have a basic clue about the human body is still believed to know what it does in detail when exposed to toxic material...
How this nonsense is still something people in 2017 believe in is baffling.