Tuskegee syphilis experiment
The researchers' original goal was to study the effects of syphilis for just six months. At first, they studied the men in the experiment for six to eight months. They were then given the only treatments that were known at the time. These included arsphenamine (which is now used as a chemotherapy), ointments made of mercury and bismuth. These treatments were all very poisonous. Some treatments helped a little while others made things worse.