professor. susan joins me by phone now. thank you for joining me. >> caller: you're welcome. >> let me find out how you came upon the information. >> caller: i was doing research on my book on the syphilis study. i was doing what historians do, which is go to archives and read dead people's mail. and i found the records in the pittsburgh -- university of pittsburgh archives of john c. cutler, the physician who did this study in guatemala. >> when you realized that 696 men and women were essentially used in this experiment, what did you think when you realized what erp reading and had researched was a reality. >> one thing i want to correct that bob bazell said. the study was to look at whether or not penicillin could be a cure. in some cases they were given syphilis and gonorrhea, they were also given penicillin to treat it. so this was an infecting study.