Allen Hornblum is an expert in criminal justice and is the author of the book, "Acres of Skin: Human Experiments at Holmesburg Prison" (Routledge). The book is about the use of prisoners as guinea pigs in the 1950s thru the mid 1970s at the Holmesburg Prison in Philadelphia. The prisoners were used to test products like facial creams, skin moisturizers, perfumes, detergents and anti-rash treatments. But they were also the subjects of experiments using more hazardous substances. The experiments were carried out by doctors at the University of Pennsylvania.