174 THE HISTORY OF SCIENCE 



were called. The founding of such an establishment 

 has been termed a scientific aberration, but the use 

 now made in medical practice of oxygen, nitrous 

 oxide, chloroform, and other inhalations bears wit- 

 ness to the sanity of the sort of research there set 

 on foot. Even before going to Bristol, Davy had in- 

 haled small quantities of nitrous oxide mixed with 

 air, in spite of the fact that this gas had been held 

 by a medical man to be the " principle of contagion." 

 He now carried on a series of tests, and finally un- 

 dertook an extended experiment with the assistance 

 of a doctor. In an air-tight or box-chamber he in- 

 haled great quantities of the supposedly dangerous 

 gas. After he had been in the box an hour and a 

 quarter, he respired twenty quarts of pure nitrous 

 oxide. He described the experience in the following 

 words : 



" A thrilling, extending from the chest to the ex- 

 tremities, 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 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 rapidly passed 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 



