The History of Forensic Science

For centuries, a perfect murder weapon existed. Tasteless and untraceable, arsenic was known as the 'inheritance powder'. This changed because of a trial in 1832, when a man named John Bodle was acquitted of murdering his grandfather. The key evidence, a crude arsenic test, deteriorated before the jury could see it. A chemist at the Royal Arsenal, James Marsh, was infuriated. He resolved to create a better method. In 1836, he perfected a glass apparatus that could detect even a tiny amount of arsenic, as little as 0.02 milligrams. It produced a stable 'metallic mirror' as undeniable proof. Thanks to Marsh, poisoners could no longer rely on their weapon being invisible, and forensic toxicology was born. The test was famously used in 1840 to convict Marie Lafarge in France.