Here's a pic of R. Gordon Wasson drinking the pressed juice of amanita muscaria in Japan, circa 1965. Wasson theorized that amanita muscaria was Soma, the hallucinogenic sacrament of the Vedas. Many different people have suggested that many different plants are in fact Soma, so take this theory with a grain of salt. My guess is that Soma has more to do with symbology than actual matter, but I tend to think of everything as symbolic.