Through out the history of science, there have been remarkably dedicated researchers, and incredibly crazy ones. These two characteristics collided in the most amazingly appalling way in the research of Stubbins Ffirth (1784-1820).
In 1793, an epidemic of yellow fever hit the city of Philadelphia. Some 4000 people of the town of 50,000 died during the course of the epidemic, and the panic was worsened by the fact that at that time the disease was so poorly understood. Trainee doctor Stubbins Ffirth became convinced that the disease was not contagious, and during a later epidemic of 1802-1803 he set out to prove it by exposing himself to the discharges and bodily fluids of the victims, among them the black vomit produced by sufferers in the late stages of the illness.
I’m not kidding. Ffirth began with animal experiments, and then exposed himself to the breath of ailing victims. Then, as described in a 1906 book, “Walter Reed and Yellow Fever,” by Howard A. Kelly,
Ffirth made numerous attempts to inoculate himself by depositing fresh black vomit and blood obtained from patients in the early stages of the disease into incisions made in his arms and legs. Besides numerous other experiments he inserted four drops of such serum into an incision in his leg. One must read this interesting treatise in order to appreciate fully the determination of the investigator, who administered black vomit to animals, injected it into his own circulation, and deposited it in his own tissues. He inhaled the fumes of six ounces of this material which he heated over a sand-bath in a small room; the residue he made into pills and swallowed. Failing in this, he further tried to inoculate himself with blood serum, saliva, perspiration, bile, and urine, and finally concluded that yellow fever was neither infectious nor contagious.
Emphasis mine. I think the description was attempting to be polite, in leaving out some of the grossest of Ffirth’s experiments. As Ffirth himself describes in his own 1804 thesis,
I took half an ounce of the black vomit immediately after it was ejected from a patient, and diluting it with an ounce and a half of water, swallowed it; the taste was very slightly acid; as I felt no mental anxiety or uneasiness, I could attend particularly to my sensations. It neither produced nausea or pain; my pulse, which was beating seventy-six in a minute, moderately strong and full, was not altered either in force or frequency: In fine, no more effect was produced than if I had taken water alone.
Emphasis again mine. I want to throw up just reading this again.
Though his methods leave much to be desired, Ffirth was correct about the contagious nature. Yellow fever is transmitted via mosquitoes, and is not directly contagious person-to-person. His belief that the fever arose from the stress of the summer months, however, was wrong, and it would not be until 1881 that Cuban scientist Carlos Finlay would correctly guess the mosquito connection.
And Finlay didn’t have to drink any vomit to figure it out!