Absinthe is an alcoholic liquor containing extracts from the wormwood plant. It was widely consumed in France in the late nineteenth century. Its production was banned in 1915, partly because it was thought to cause neurological disturbances, including mental changes and epileptic seizures. Modern knowledge of an acceptable content of the convulsant alpha-thujone in absinthe has allowed the lifting of the production bans, and called into question the experimental work of Valentin Magnan in the 1870s, which formed the scientific background to the campaign against absinthe. An examination of Magnan's published investigations suggests that his science was very adequate by the standards of his time, and that he had shown that an alcohol-soluble component of wormwood did produce lapses of consciousness, myoclonic jerks and tonic-clonic convulsions in animals. Whether that component, presumably thujone, was present at convulsant concentrations in some of the available absinthes of Magnan's time cannot now be known.