Edme-Samuel Castaing (1796 – 6 December 1823) was a French physician[1] and is thought to have been the first person to use morphine to commit murder.

He graduated from the School of Medicine in Paris, becoming a doctor in 1821, by which time he had fathered two children with his mistress, the widow of a judge.

In October 1822 Hippolyte died from a sudden illness, leaving 260,000 francs to be split between his brother Auguste and their sister.

Castaing, who had been treating Hippolyte, and another doctor conducted the autopsy, concluding that he had died of pleurisy aggravated by consumption.

Auguste would later claim that this was to be used as a bribe to get the family lawyer, Lebret, to destroy a will by Hippolyte that favoured the brothers' sister.

[3] Castaing was defended by two advocates: Roussel, a schoolfellow of his, and the famous Pierre-Antoine Berryer, though the latter's speech is not considered one of his most successful ones.

He said that with the help of his own chemist he had put a quarter of a grain of the acetate into a large spoonful of milk, and had found it so insupportably bitter to the taste that he could not keep it in his mouth."

[3]After a failed appeal and a suicide attempt (using poison hidden inside a watch, which was brought to him in prison by a friend), he was executed on December 6, 1823.