Chapter 9

Poisons

= chemicals that can harm the body if ingested, absorbed, or inhaled in sufficiently high concentrations

Can detect and measure small amounts in human tissue

History of Toxicology Early 1700s – used chemistry to detect

poisons Dutch chemist, Hermann Boerhaave –

arsenic has distinct odor when heated, but ineffective method in body

Others developed techniques to measure poisons in body

Early 19th century – new scientific discipline

France, 1840 – 1st use in legal case – LaFarge murder trial

Marie accused of killing husband, Charles, with rat poison (arsenic)

English chemist, James Marsh – test to detect arsenic

Found traces of arsenic in food, but not body

Orfila retested exhumed body Found traces of arsenic in body, but not

surrounding soil So, not absorbed by body after burial Marie LaFarge convicted of murder

Forensic Toxicologist Concerned with legal and medical

aspects of alcohol, drugs, poisons, and toxins in bodily fluids

Often works with pathologist Analyzes evidence to determine if

alcohol or drugs contributed to crime Presents expert testimony