Curare: The Poisoned Arrow that Entered the Laboratory and Sparked a Moral Debate.

Curare, a paralysing poison derived from South American plants, fascinated European explorers with its deadly powers. Generations of travellers were perplexed by how animals affected by curare showed no signs of suffering. British experimenters relabelled curare as an anaesthetic and used it to restrain animals during experiments. But during the 19th century, doubts started to appear: can a paralysed animal feel pain but be unable to express it? A scientific dispute emerged as not all British physiologists accepted Claude Bernard's claim that curare affected only the motor nerves. The scientific controversy over curare reached the British parliament, and the Cruelty to Animals Act (1876) stated that curare would not be considered an anaesthetic. Nevertheless, antivivisection advocates continued to contest its use for decades. The article reveals new aspects of colonial import of bioactive plants in a case that reshaped the production of medical knowledge and presented epistemological and moral challenges.