Immediately after a journey of 126 miles, in which I had no sleep the preceding night, being much exhausted, I respired seven quarts of gas for near three minutes. It produced the usual pleasurable effects, and slight muscular motion. I continued exhilarated for some minutes afterwards: but in half an hour found myself neither more or less exhausted than before the experiment. I had a great propensity to sleep. I repeated the experiment four or five times in the following week, with similar effects. My susceptibility was certainly not diminished. I even thought that I was more affected than formerly by equal doses. Though, except in one instance, when indeed the gas was impure, I had experienced no decisive exhaustion after the excitement from nitrous oxide, yet still I was far from being satisfied that it was unanalogous to stimulants in general.—No experiment had been made in which the excitement from nitrous oxide had been kept up for so great a length of time and carried to so great an extent as that in which it is uniformly succeeded by excessive debility under the agency of other powers. It occurred to me, that supposing nitrous oxide to be a stimulant of the common class, it would follow that the debility produced in consequence of excessive stimulation by a known agent, ought to be _increased_ after excitement from nitrous oxide.[215] [215] In the same manner as the debility from intoxication by two bottles of wine is increased by a third. To ascertain whether this was the case, I made on December 23d, at four P. M. the following experiment. I drank a bottle of wine in large draughts in less than eight minutes. Whilst I was drinking, I perceived a sense of fulness in the head, and throbbing of the arteries, not unanalogous to that produced in the first stage of nitrous oxide excitement. After I had finished the bottle, this fulness increased, the objects around me became dazzling, the power of distinct articulation was lost, and I was unable to walk steadily. At this moment the sensations were rather pleasurable than otherwise, the sense of fulness in the head soon however increased so as to become painful, and in less than an hour I sunk into a state of insensibility.[216] [216] I ought to observe that my usual drink is water, that I had been little accustomed to take wine or spirits, and had never been compleatly intoxicated but once before in the course of my life. This will account for the powerful effects of a single bottle of wine. In this situation I must have remained for two hours or two hours and half. I was awakened by head-ache and painful nausea. The nausea continued even after the contents of the stomach had been ejected. The pain in the head every minute increased; I was neither feverish or thirsty; my bodily and mental debility were excessive, and the pulse feeble and quick.