ABSTRACT
The drugs known variously as the hallucinogens, the Central Nervous System (CNS) stimulants, and cannabis are by name and reputation a varied collection of materials. A hallucinogen is a substance that creates some unexplained and unconfirmable imagery, a CNS stimulant clearly invokes some anatomical or physiological site of action, and cannabis is the generic name of a plant. The most widely known drug of this entire group is the semisynthetic compound, lysergic acid diethylamide, lysergic acid diethylamide -25. The simplest of the central stimulants and the parent structure to a large number of active compounds, both as sympathomimetic stimulants and as psychotomimetics, is the chemical phenethylamine. The latter pharmacological property appears to be the more dominant, as changes simultaneously in both areas of the molecule yield hallucinogens that are of increased potency, but do not promote appreciable stimulation. The only heterocyclic system mentioned so far has been the indole system and it is indeed paramount in most alkaloidal chemical systems.
