NITROUS OXIDE. 481 



tremities. The objects around me became dazzling, and my hear- 

 ing more acute. Towards the last inspiration the thrilling increased, 

 the sense of muscular power became greater, and at last an irresist- 

 ible propensity to laughter was indulged in ; I recollect but indis- 

 tinctly what followed ; I know that my motions were various and 

 violent. These effects soon ceased after respiration. In ten min- 

 utes I had recovered my natural state of mind. The thrilling in the 

 extremities continued longer than the other sensations." 



(d.) " The effects of the nitrous oxide on the human system are 

 analagous to a transient, peculiar, various, and generally very viva- 

 cious ebriety." Dr. Hare. 



(e.) It differs from all other diffusible stimuli in not being attend- 

 ed by any subsequent depression ; in general, on the contrary the 

 violent effects gradually subside into cheerfulness, and manifest them- 

 selves by gayety and activity, which sometimes continue for hours, 

 and even in particular cases for days. 



(f.) The general dose is from 4 to 6 or S quarts of the gas. JIX 

 (g.) It is breathed into and from a silk bag, or an air 

 jar furnished with a stop cock, of a wide bore, or with 

 a arge bent tube, as in the annexed cut : and the action 

 ofl the lungs may be relieved by having an assistant to hold 

 the jar over the well of the pneumatic cistern, so that it, 

 may rise and fall; a small gasometer is still more con-= 

 venient. 



(h.) The effects are not always agreeable. Some persons are not 

 excited, but are rather depressed, and also fatigued, by the constrained 

 mode of breathing. Some become faint and fall as in a Jit or swoon; 

 but they in general soon recover, as if from a troubled dream or a turn 

 of nightmare ; some are rendered apparently, apoplectic, and others 

 are thrown into a temporary, but often violent delirium, and in such 

 cases the subsiding feelings are disagreeable. 



(i.) There is good ground for caution, and it would now be 

 proper that the practice of breathing the nitrous oxide should be dis- 

 continued, except for medical purposes.* 



Remark. Although we can offer no satisfactory theory to account 

 for the action of the nitrous oxide, it cannot but be regretted, that so 

 powerful a stimulus both of our physical and inellectual powers should 



* Among multitudes to whom I have administered this gas, about 6 out of 8 have 

 been agreeably affected ; but there has been very great variety in the appearances, 

 influenced, in most cases, apparently, by the physical and moral temperament of the 

 subject. I have seen not a few cases attended by symptoms so violent and alarming 

 that I have been very glad when they have subsided. I have personally known 

 no instance of fatal effects, either immediate or remote ; but some have thought 

 themselves injured for a considerable period, and it has always been a subject of 

 anxiety lest some idiosyncrasy should,) produce an unhappy termination. The ex- 

 perience of Thenard, Vanquelin, and their companions was altogether painful. 

 See Thenard's Chem. 



61 



