syphilis, with classic examples in literature including John Keats' "La Belle Dame sans Merci". The Flemish artist Stradanus designed a print called Preparation and Use of Guayaco for Treating Syphilis, a scene of a wealthy man receiving treatment for syphilis with the tropical wood guaiacum sometime around 1590. Tuskegee and Guatemala studies The "Tuskegee Study of Untreated Syphilis in the Negro Male" was an infamous, unethical and racist clinical study conducted between 1932 and 1972 by the U.S. Public Health Service. Whereas the purpose of this study was to observe the natural history of untreated syphilis; the African-American men in the study were told they were receiving free treatment for "bad blood" from the United States government. The Public Health Service started working on this study in 1932 in collaboration with Tuskegee University, a historically black college in Alabama. Researchers enrolled 600 poor, African-American sharecroppers from Macon County, Alabama in the study. Of these men, 399 had contracted syphilis before the study began, and 201 did not have the disease. Medical care, hot meals and free burial insurance were given to those who participated. The men were told that the study would last six months, but in the end it continued for 40 years. After funding for treatment was lost, the study was continued without informing the men that they were only being studied and would not be treated. Facing insufficient participation, the Macon County Health Department nevertheless wrote to subjects to offer them a "last chance" to get a special "treatment", which was not a treatment at all, but a spinal tap administered exclusively for diagnostic purposes. None of the men infected were ever told that they had the disease, and none were treated with penicillin even after the antibiotic had been proven to successfully treat syphilis. According to the Centers for Disease Control, the men were told they were being treated for "bad blood"—a colloquialism describing various conditions such as fatigue, anemia and syphilis—which was a leading cause of death among southern African-American men. The 40-year study became a textbook example of poor medical ethics because researchers had knowingly withheld treatment with penicillin and because the subjects had been misled concerning the purposes of the study. The revelation in 1972 of these study failures by a whistleblower, Peter Buxtun, led to major changes in U.S. law and regulation on the protection of participants in clinical studies. Now studies