In July 1699, Spencer Cowper, a prominent English barrister and future judge, stood trial for the murder of Sarah Stout, a wealthy Quaker woman found dead in the River Lea at Hertford. Stout's body had been discovered floating on the surface of the water the morning after Cowper had visited her home. Because Stout was a Quaker, her family initially resisted an autopsy, but rumors of murder forced an exhumation and a legal showdown that introduced early, unscientific medical testimony to the courtroom.
The prosecution argued that Stout's body floated because she had been strangled and thrown into the river post-mortem. According to popular medical belief of the era, a live person who drowned would swallow large amounts of water, making the corpse heavy enough to sink, whereas a dead body tossed into water would retain air and float. To support this theory, prosecution witnesses produced sailors who swore that drowned sailors always sank to the bottom.
Cowper mounted a rigorous defense backed by prominent physicians, including Dr. Samuel Garth and Dr. Hans Sloane, founder of the British Museum.
The defense medical experts argued that fluid retention depended on body composition, clothing, and water currents rather than whether death occurred before or after immersion. They conducted crude experiments in court, debating physical decomposition and lung capacity without any standardized forensic precedent. The trial exposed the wild inconsistency of late 17th-century forensic medicine.
Ultimately, the lack of definitive scientific proof and Cowper's strong alibi led to his acquittal, highlighting the urgent need for empirical pathology in criminal law.