In 1972, a venereal-disease investigator, now studying law, told an AP reporter what he knew about an obscure ""Tuskegee Study""--and one of the most shameful medical experiments ever conducted in this country came to fight: a 40-year, non-therapeutic study by the US Public Health Service of the effects of untreated syphilis on 399 black men in Alabama. When the story broke, Jones was a Kennedy Fellow in Bioethics at Harvard, and he has methodically investigated the serious questions that were not answered in the brief medical and public discussions following the story's publication: was the PHS interested in syphilis in blacks, or using blacks to study syphilis? Why was treatment withheld, especially after penicillin became available? Why did the subjects cooperate? Why did an all-black facility, as the Tuskegee Institute was in 1932, cooperate? Was there ever any opposition to the study? How did the doctors and one nurse notably involved view what they were doing? The main players, here, are those who planned, directed, and carried out the study; and against this background, the experiment is fitted into the development of the public health movement in the US. No one, Jones finds, ever strenuously questioned the morality of a study which withheld an established, effective treatment from the subjects; as a scientific study, the whole exercise was poorly designed (subjects dropped out, some were treated for other diseases--which may have affected their syphilis); subjects agreed to participate because 1) they were mostly illiterate and didn't understand the terms, 2) they were poor and received free medical care for minor ailments, 3) when they died (usually of neurologic or cardiac complications of the disease), their families received a $50 burial stipend (made possible by a grant from the respected Milbank Memorial Fund). A vital factor in keeping the program going, Jones found, was a black public health nurse named Rivers, who was hired to follow the men and their families for the entire study; who tracked them down when they moved, drove them to doctor's appointments, attended their funerals. (Even in 1972, when publicity brought the experiment to a close, she would refuse to believe it had harmed the men.) In 1975, as the result of a lawsuit, the government settled with the study's survivors for free medical care for the rest of their lives, treatment for afflicted wives and children, the long-established burial stipend, and some payment for damages; one of the institutional effects was the creation of standards for treatment of human subjects in experiments. One learns here almost nothing of the subjects; it is only by a chance remark that we realize that because the men weren't treated, their wives were also infected and their children were born with congenital syphilis. And larger questions--the part racism and class-ism played, whether we need to look even harder at our current research--are mainly left to readers' own consideration. But Jones' solid, thought-provoking evidence, gravely presented, makes its own comment.