It became very popular in the 19th century, but was eventually banned in most countries beginning in 1908. The reason is the presence of the toxic oil 'thujone' in wormwood, which was one of the main ingredients of Absinthe. Absinthe seemed to cause brain lesions, convulsions, hallucinations and severe mental problems. Thujone was thought to be the culprit, along with the fact that Absinthe was manufactured with an alcohol content of 68% or 132 proof.