WHAT MORTAL MIND FELT AND SAW

An investigator's experiment he describes as follows: I began to respire twenty quarts of unmingled nitrous oxide. A thrilling, extending from the chest to the extremities, was almost immediately produced. I felt a sense of tangible extension, highly pleasurable in every limb. My visible impressions were dazzling and apparently magnified. I heard distinctly every sound in the room, and was perfectly aware of my situation. By degrees, as the pleasurable sensations increased, I lost all connection with external things; trains of vivid, visible images passed rapidly through my mind, and were connected with words in such a manner as to produce perceptions perfectly novel. I existed in a world of newly connected and newly modified ideas. I theorized; I imagined that I made discoveries. When I was awakened from this semi-delirious trance by Dr. Kinglake, who took the bag from my mouth, indignation and pride were the first feelings produced by the sight of the persons about me. My emotions were enthusiastic and sublime, and for a minute I walked around the room perfectly regardless of what was said to me. As I recovered my former state of mind, I felt an inclination to communicate the discoveries I had made during the experiment. I endeavored to recall the ideas; they were feeble and indistinct. One collection of terms, however, presented itself, and with the most intense belief and prophetic manner. I exclaimed to Dr. Kinglake: "Nothing exists but thought. The universe is composed of impressions, ideas, pleasures, and pains." About three minutes and a half only had elapsed during this experiment, though the time, as measured by the relative vividness of the collateral ideas, appeared to me much longer.