I was driving down Haight Street the other day, and coming in the opposite direction was the Further Bus with Ken Kesey standing on the top-deck in a psychedelic suit. I honked my horn and flashed the piece sign as they went by, and for a brief moment I met eyes with Mr. Kesey.
This morning I found this article on CIA experiments with LSD, which included a video with some great old footage of the Merry Pranksters: Kesey discusses how government experimentation with LSD ultimately led to its introduction into the subculture. Another article that I found seems to corraborate that the government used people as "lab rats" for experimentation with all kinds of dangerous substances such as nerve agents and other poisons.
Here is an old article from the 1960's written while Kesey was "on the lam."