dr. humphries, did we learn -- make medical advances during the civil war as well? >> guest: there's a few things. it's hard to point to something specific. it's not like, for example in world war ii, doctors learned to use penicillin. they learned about ddt, to control the malaria mosquito. the civil war, more of what you get this dissemination of ideas that a few doctors knew but every doctor left the war knowing. for example, chloroform was new nieca. a lot of doctors were suspicion and thought it was dangerous. the british in the crima, for example -- the crimea, for example in the mid-1850s, wrote it's dangerous to use chloroform, and we had these deaths from chloroform. well, by the end of the civil war, i think it's fair to say that every surgeon, union or confederate, knew how to use chloroform and use either anesthesia and now how to do amputations. and they learned about contagious diseases diseases ano control them with fresh air and the cleanliness. but they had concepts about what caused wound infections but if they tacted on them, worked. so, if gangre

dr. humphries, professor of history and professor over medicine and an md. written two other books, intensely human and malaria. you're watching booktv from can do university -- duke university. >>> booktv asked what are you reading this summer? >> i think i'm doing a catchup summer. reading a lot of things that are not particularly new but i have meant to read and not gotten done. so i ticked off also list of them, and they start with two sort of real life rescue stories from world war ii. one i'm reading now, the book, "frozen in time" about some american aviators who crashed in greenland in the second world war. then the rescue mission that went after them and also went down, and another one that disappear, and they finally did rescue these guys, who lived for months in the tail of an airplane. a gripping story. then the second part is about an expedition to go back and find the people who were lost trying to rescue the original crew, and they located aircraft and all kinds of things. so it's a great story. in reading that, of yours you read the book jack

dr. margaret humphries talked to booktv about the civil war which she says was the greatest health disaster. has ever experienced. >> host: and booktv is on location in durham, north carolina, where we're talking with some professors who are also authors. joining us now is dr. margaret humphreys. her book, "marrow of tragedy: the health crisis of the american civil war." you write that the civil war was the greatest health disaster the u.s. has ever experienced. that's your opening line. >> guest: true. >> host: how so? >> guest: how so. well, i mean, if you, you can count the numbers many ways, but one probably conservative estimate is that more than a million people died in those five years that would not have died, as they call premature or unexpected deaths because of that war. and it is useful to think of war as a health crisis, because you think about the women who died, the children who starved, the refugees who died of disease, the people who died this prisoner of war camps. not just the ones who died from wounds or actually while in the army. >> host: what were some of the health p