"I had in my possession some carbon tetrachloride, which I used to kill beetles for my collection. Knowing this substance belongs to the same chemical family as chloroform (it is even more toxic), I thought I could regulate its action very simply and easily: the moment I began to lose consciousness, my hand would fall form my nostrils carrying with it the handkerchief moistened with the volatile fluid. Later on I repeated the experiment in the presence of friends, who could have given me help had I needed it. The result was always exactly the same; that is, it exceeded and even overwhelmed my expectations by bursting the limits of the possible and by projecting me brutally into another world." - Rene Daumal, "A Fundamental Experiment"
published in Psychedelic Review, No. 5, 1965, p. 40 - 49 [PDF]