Yes, LSD was synthesized by Dr Albert Hofmann in 1943, and he discovered
its mind-altering properties while riding his bicycle on the way
home. This is a quote from his laboratory notes:

    I suddenly became strangely inebriated. The external world became
    changed as in a dream. Objects appeared to gain inrelief; they
    assumed unusual dimensions; and colors became more glowing. Even
    self-perception and the sense of time were changed. When the eyes
    were closed, colored pictures flashed past in a quickly changing
    kaleidoscope. After a few hours, the not unpleasant inebriation, which
    had been experienced whilst I was fully conscious, disappeared. what
    had caused this condition?

More information can be found here [erowid.org] and here [hofmann.org].
http://www.erowid.org/chemicals/lsd/lsd.shtml http://www.hofmann.org/