Although dozens of species of psychedelic mushrooms are found in Europe, there is little documented usage of these species in Old World history besides the use of Amanita muscaria among Siberian peoples. The few existing historical accounts about psilocybin mushrooms typically lack sufficient information to allow species identification, and usually refer to the nature of their effects. For example, Flemish botanist Carolus Clusius (1526–1609) described the bolond gomba (crazy mushroom), used in rural Hungary to prepare love potions. English botanist John Parkinson included details about a "foolish mushroom" in his 1640 herbal Theatricum Botanicum. The first reliably documented report of intoxication with Psilocybe semilanceata—Europe's most common and widespread psychedelic mushroom—involved a British family in 1799, who prepared a meal with mushrooms they had picked in London's Green Park. Modern American banker and amateur ethnomycologist R. Gordon Wasson and his wife Valentina P. Wasson, a physician, studied the ritual use of psychoactive mushrooms by the native population in the Mazatec village Huautla de Jiménez, Mexico. In 1957, Wasson described the psychedelic visions that he experienced during these rituals in "Seeking the Magic Mushroom", an article published in the popular American weekly Life magazine. Later the same year they were accompanied on a follow-up expedition by French mycologist Roger Heim, who identified several of the mushrooms as Psilocybe species. Heim cultivated the mushrooms in France, and sent samples for analysis to Albert Hofmann, a chemist employed by the Swiss multinational pharmaceutical company Sandoz (now Novartis). Hofmann, who had in 1938 created LSD, led a research group that isolated and identified the psychoactive compounds from Psilocybe mexicana. Hofmann was aided in the discovery process by his willingness to ingest mushroom extracts to help verify the presence of the active compounds. He and his colleagues later synthesized a number of compounds chemically related to the naturally occurring psilocybin, to see how structural changes would affect psychoactivity. The new molecules differed from psilocybin in the position of the phosphoryl or hydroxyl group at the top of the indole ring, and in the numbers of methyl groups (CH3) and other additional carbon chains. Two diethyl analogs (containing two ethyl groups in place of the two methyl groups) of psilocybin and psilocin were synthesized by Hofmann: 4-phosphoryloxy-N,N-diethyltryptamine, called CEY-19, and 4-hydroxy-N,N-diethyltryptamine, called CZ-74. Because their physiological effects last only about three and a half hours (about half as long as psilocybin), they proved more manageable in European