ON THE ACTION OF THE METHYL AND ALLIED SERIES. 167 



to the vapour, pigeons aud rabbits glide into the deepest sleep of unconscious- 

 ness without a movement, and in a state more strikingly resembling natural 

 sleep than any other condition ; the insensibility may be sustained for two 

 hours without the least apparent danger. Within the last ten da3'S, after 

 first inhaling the vapour myself, I administered it to the human subject, 

 while Mr. Brudenell Carter performed an operation on the eyeball for the cure 

 of strabismus. The action in this instance was simply perfect ; the patient 

 subsided into what seemed a natural sleep, without a convulsive or disturbed 

 movement; the operation was performed without the faintest manifestation 

 of sensation, and recovery was perfect in one minute after the vapour was 

 withdi-awn*. The experience of the action of the narcotic I have here 

 described is so good that I could not let it pass silently ; but I am not yet sure 

 whether the application can be brought into general use. The production of 

 the fluid is troublesome and costly, and after a time, if exposed to the air, 

 it loses its efficacy. Tn brief, it is not a homogeneous substance, and is 

 therefore open to the objections against compound fluids mentioned in my 

 Report at the Norwich Meeting. The part played by the heavy ether is 

 excellent, in that it equalizes diff'usion and prevents pungency of vapour ; 

 aud I may be able, by further research, to improve the method, or to be guided 

 by what I know of it to some new and better advance ; but this I must leave 

 for future research. 



The tnmeilijjUc ether of which I have spoken is a much lighter fluid than 

 the triethyhc ; it boils at 140° F., and has a vapour-density of 53 ; but the 

 odour of its vapour is not agreeable, and although it produces safe auajsthesia, 

 it is not perfect in its action. 



PAET III.— PHYSIOLOGICAL CONSIDERATIONS. 



In conducting a lengthened series of experiments such as I have been 

 engaged in carrying out during the past year, many observations, incidental 

 to the work in hand, naturally come before the mind, and to one or two 

 observations of this character I would, for a moment, direct attention in 

 closing the Report. 



Consciousness and common sensation. — The metaphysicians, in treating of 

 conscious and unconscious states of mind, have long taught that there may 

 be periods of consciousness with an absence of common sensibility. The 

 truth of this inference is sustained by physical inquiries. In a previous 

 Report on Amylene I pointed out that the vapour of amylene, while it 

 destroys sensation, does not destroy all conscious acts; and in my later obser- 

 vations on the action of methylic ether the same fact has been more perfectly 

 elicited. In several cases where I administered the ether for removing pain 

 in surgical operations, the patients, when quite insensible to pain, were so 

 conscious that they were able to obey every request asked of them ; and in some 

 instances were even anxious to reason, stating that they knew what was going 

 on, and arguing that they were not ready for the operation because they were 

 sure they should feel pain. Nevertheless in this state of mental activity they 

 were operated on, and afterwards, while remembering every incident, were 

 firm in their assertion that they felt no pain whatever during the operation. 

 One patient who sat for the extraction of two teeth selected the tooth to be 



* During the Meeting of the Association at Liverpool I administered the same vapour 

 to a woman over seventy years of age, while my friend Mr. Walker operated for cataract. 

 The results were as perfect as in Mr. Carter's case. 



