Although Norvig's assumption that Fisher probably died of colorectal cancer because of smoking is not necessarily true - after all, prostate cancer and then colorectal cancer are the most prevalant cancer in males (and not lung c., as you die of it), and col. c. is one of the four most deadliest cancers. Oh well, only my smoker-addiction can keep up this argument to keep me doing it, I guess. ;)
http://norvig.com/experiment-design.html
has a funny photo related to this statement.