A fun, accessible collection of stories from modern medicine's history when doctors experimented upon themselves.
Admittedly, it's not the kind of book you pick up just for kicks, and I first read it for a History of Science class, but I LOVED it. You'll be amazed how many things from our modern medicine began with really dangerous experiments that doctors first did upon themselves (typically, because they felt the question was important enough to taking the risk, but they didn't want to put other people at such high risks, and so chose to do it themselves.) Everything from nutrition to yellow fever, to seat belts to leukemeia and cancer, an then some.
Some stories make you wonder about the sanity of those docs, but it's eye-opening, and fascinating. And the author, Dr. Lawrence, is a guy who writes for the New York Times, and he knows how to write for an audience who has little or no background in medicine.
A while back, my family had its own book-reading group, and I had them read this when it was my turn to pick, and almost all of them really enjoyed it, too.