By Angelika Börsch-Haubold
Science in School, Issue 4 (2007)
“Were such things here as we do speak about?
Or have we eaten on the insane root
That takes the reason prisoner?”
- Shakespeare, Macbeth
Thus wonders Banquo, who witnessed, together with Macbeth, the witches’ sabbath and the first foretelling of their future at the beginning of Shakespeare’s play. The apparitions were either true – or a hallucination. By giving these two options in 1606, at the height of the witch-hunt in Europe, Shakespeare not only provides a reasonable interpretation of the state of bewitchment, i.e. of delirious dreams, but also points to a possible cause of this insanity. There are poisonous plants that, upon contact or ingestion, cloud our mind and make us experience unreal sensations. As the deplorable persecution of witches tells us, most Europeans unfortunately lacked such botanical knowledge at that time.
The “insane root” may well have been mandrake (Mandragora officinarum), the most famous magic plant of the Mediterranean, sold at high prices in markets north of the Alps. Since the root can resemble a human body, mandrake was believed to contain a spirit that brings fortune and guards against evil those who own or carry the root. However, it was a dangerous business to dig up the plant, as it would issue a deadly shriek when taken from the earth. For this purpose, people were advised to fasten a dog to the half-exposed root and let the animal draw the plant out, a ritual that is often depicted in medieval books. Hundreds of years later, Goethe’s Mephistopheles makes fun of this superstition: ‘There they stand and marvel, not believing in the precious find; one drivels of mandrake, the other of the Black Dog.” Goethe, Faust II, Act I).
Mandrake and other plants of the nightshade family (Solanaceae) contain alkaloids that block nerve impulses, which may lead to hallucinations. Although the cellular and molecular mechanism of action was only explained at the end of the 20th century, the pharmacological effects of these plants were already described by the Greco-Roman physicians Dioscurides (1st century AD) and Galenus (circa 129-199) and, from the 16th century onwards, by authors of herbal medicine books in local languages. The plants deadly nightshade (Atropa belladonna) and henbane (Hyoscyamus niger) are indigenous to middle and northern Europe and were therefore readily available for medicinal use or narcotic and poisonous abuse. The physician Leonhart Fuchs explains in his New Kreüterbuch (printed in 1543) how to apply parts of these plants as sleeping agents and painkillers. In addition, he warns of their narcotic and toxic effects. He also groups the plant thorn-apple (Datura stramonium), which had recently been brought to Europe by travellers from India or Mexico, botanically correctly with the nightshades, but admits his ignorance of its medicinal usage.