It is twenty years since the appearance of Stoll's paper: “Lysergic acid diethylamide, a hallucinatory agent of the ergot group” (23). In this he sought to reproduce in a group of subjects Hofmann's personal experiences of the drug, and so set the LSD snowball on its way. Some 1,500 papers must by now have been gathered to it; they deal with a greater range of uses than has been thought of for...