Poisons are among the favorite weapons of mystery writers, if not murderers. Guns may be quicker, but poisons have a cachet that you really can't beat. On the other hand, murder by poison has become increasingly dangerous - to the perpetrator! Despite the fact that incredibly small amounts of certain chemicals constitute a lethal dose, resourceful forensic scientists have pushed the limits of quantification to even smaller values. It is amazing that a person can be killed with only micrograms of a few substances (think about what a microgram would look like), but even more so that they are always detectable in a corpse. "Molecules of Murder" recounts some of the most infamous murders by poison in a style that will appeal to chemists and students of chemistry. While he does not provide chemical structures for the toxins (so as not to put off the non-chemical reader), skilled science writer John Emsley [author of other Hal's Picks in November 2001 and July 1998] deftly describes the murders and the murderers in a case-by-case style that never speaks down to his audience.