The psychedelic alkaloid mescaline occurs naturally in peyote cactus and other plants. And though it became popular in the mid-20^th Century, its use dates back to the earliest Andean cultures. Mike Jay joins guest host John McCaa to tell the stories of seekers through the years who have experimented with mescaline in search of new states of consciousness, which he writes about in “Mescaline: A Global History of the First Psychedelic” (Yale University Press)