A HISTORY OF SCIENCE 



"To ascertain with certainty whether the more 

 extensive action of nitrous oxide corr-patible with life 

 was capable of producing debility, I resolved to breathe 

 the gas for such a time, and in such quantities, as to 

 produce excitement equal in duration and superior in 

 intensity to that occasioned by high intoxication from 

 opium or alcohol. 



" To habituate myself to the excitement, and to carry 

 it on gradually, on December 26th I was enclosed in 

 an air-tight breathing-box, of the capacity of about 

 nine and one-half cubic feet, in the presence of Dr. 

 Kinglake. After I had taken a situation in which I 

 could by means of a curved thermometer inserted 

 under the arm, and a stop-watch, ascertain the altera- 

 tions in my pulse and animal heat, twenty quarts of 

 nitrous oxide were thrown into the box. 



" For three minutes I experienced no alteration in my 

 sensations, though immediately after the introduction 

 of the nitrous oxide the smell and taste of it were very 

 evident. In four minutes I began to feel a slight glow 

 in the cheeks and a generally diffused warmth over 

 the chest, though the temperature of the box was not 

 quite 50. . . . In twenty-five minutes the animal heat 

 was 1 00, pulse 124. In thirty minutes twenty quarts 

 more of gas were introduced. 



" My sensations were now pleasant ; I had a generally 

 diffused warmth without the slightest moisture of the 

 skin, a sense of exhilaration similar to that produced 

 by a small dose of wine, and a disposition to muscular 

 motion and to merriment. 



" In three-quarters of an hour the pulse was 104 and 

 the animal heat not 99.5, the temperature of the 



210 



