EFFECTS OF INTOXICATING GAS. 387 



sensation and voluntary power, a feeling analogous to that 

 produced in the first stage of intoxication, but unattended 

 by pleasurable sensations." In describing the effects of 

 another experiment, he says, " Having previously closed 

 my nostrils and exhausted my lungs, I breathed four 

 quarts of nitrous oxide from and into a silk bag. The 

 first feelings were similar to those produced in the last 

 experiment, but in less than half a minute, the respiration 

 being continued, they diminished gradually, and were 

 succeeded by a highly-pleasurable thrilling, particularly 

 in the chest and the extremities. The objects around me 

 became dazzling, and my hearing more acute. Towards 

 the last respiration the thrilling increased, the sense of 

 muscular power became greater, and at last an irresistible 

 propensity to action was indulged in. I recollect but 

 indistinctly what followed ; I knew that my motions were 

 varied and violent. These effects very rarely ceased after 

 respiration. In ten minutes I had recovered my natural 

 state of mind. The thrilling in the extremities continued 

 longer than the other sensations. This experiment was 

 made in the morning; no languor or exhaustion was 

 consequent, my feelings through the day were as usual, 

 and I passed the night in undisturbed repose." 



In giving an account of another experiment with this 

 gas, Sir Humphry thus describes his feelings : " Imme- 

 diately after my return from a long journey, being 

 fatigued, I respired nine quarts of nitrous oxide, having 

 been precisely thirty-three days without breathing any. 

 The feelings were different from those I had experienced 

 on former experiments. After the first six or seven 

 respirations, I gradually began to lose the perception of 

 external things, and a vivid and intense recollection of 

 some former experiments passed through my mind, so 

 that I called out, * what an annoying concatenation of 

 ideas.' " 



