So we live in what I think of as a CSI age, where we take for granted（授予） that scientists are going to work together with the police, help them solve crimes, map fingerprints, analyze poisons（毒）, but in fact this is really a very new idea. We only actually started training scientists and forensics（法院的） in this country in the 1930s. So as a writer interested in chemistry, what I wondered（想知道） was, what was it like（喜欢） before scientists knew how to tease a poison（毒） out of a corpse before you could actually catch a killer that way? And it won't surprise you to learn that the answer is pretty dangerous. And in fact in 1918, New York City issued（发行） a report admitting（承认） that smart（聪明的） poisoners could operate with impunity in the city. This is a 1918 crime scene photo from Brooklyn, and at this time the coroner system was so corrupt（腐败的） that you could literally（照字面地） buy your cause of death.

  Often coroners didn't even show up at crime scenes, and if you go back and you look at the death certificates（证书） of the time, I found one that read, "Could be an auto（(口语)汽车） accident, or possibly（可能地） diabetes." And another, which involved a man who shot himself in the head, said "ruptured aneurysm." So you find, not surprisingly, the police saying "we're going to look a lot smarter if we stay away from the science side of the story." But in 1918, New York City appointed（任命） the first trained medical examiner it ever had. That's the gentleman（绅士） sitting down there. And he hired（租借） the first forensic（法院的） toxicologist ever attached（缚） to an American city.

  And together these two men, Charles Norris, the medical examiner, and Alexander Geller, the chemist sitting next to him, rewrote the rules of crime detection（察觉） in this country. And that wasn't easy because poisons were everywhere. If we take this one, arsenic（[化]砷） trioxide, arsenic trioxide's probably the most famous homicidal poison in history, and it was in every home. Anyone could go to the grocery（食品杂货店） store, the pharmacy（药房）, and buy it. It was in every kitchen because, believe it or not, it was used to color food. It was in medicines, and it was in cosmetics in ways that prevented people from really understanding how dangerous these poisons were or how they worked.