The first reason for dealing with the Banisterin alkaloid gave investigations into a drug that is still in use in Central and South America at the natives today. Lewin has reported this under "Banisteria Caapi" in his book "Phantastica" and now in "Investigations about Banisteria Caapi Spr. According to the indications of the natives and self-tests Weisser, the effect on mental areas shows, in addition to a change in the noise-like and sometimes leading excitations, which is not yet known, the effect of the sense-warning and also in the occurrence of sense-deception of the face and hearing. The toxic noise produces a series of apparently highly remarkable psychopathological phenomena that have in some similarity to the experiences in the mescalin intoxication.