A newly discovered letter reveals that doctors knew about the risk tobacco posed to people’s health as early as the 18th century.

(Medical student William Adams, wrote to his father in 1799 saying how he feared his mother’s pipe-smoking habit was harmful. He said tobacco had a narcotic power, and its use destroyed digestion. Adams, who was studying in Edinburgh, also referred to a case where a woman had died after being given the wrong dose of tobacco by a chemist.)