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Nitrous oxide, he said, administered in large doses, produces 

 great excitement, which increases with the quantity inhaled. The 

 vapor of chloroform, on the other hand, when inhaled rapidly, 

 causes an immediate and entire prostration. The same is true in 

 a less degree, of sulphuric ether. They do not produce the 

 intoxication which is caused by nitrous oxide. This agent 

 administered slowly, fails to produce the usual effects. In 

 1837-8 Dr. Jackson administered it to his pupils from a bag 

 with a very small aperture, without in any instance succeeding 

 in causing intoxication. The vapor of chloroform slowly inhaled 

 has an injurious influence. It disorganizes the blood, and stops 

 the circulation in the capillaries. When suddenly introduced it 

 retards, but does not stop the circulation. Patients to whom it is 

 slowly administered recover slowly. It is very important that 

 enough air should be admitted with it. Persons inhaling nitrous 

 oxide retain the sensibility to touch, and the respiratory action is 

 quickened, increases and becomes deeper as the inhalation is 

 prolonged. During the inhalation of chloroform and ether, on 

 the contrary, the respiratory power diminishes. Under the influ- 

 ence of exhilarating gas the system is made very irritable. 

 According to Davy it is not a suitable agent for producing insen- 

 sibility in grave surgical operations. Dr. Jackson thought that 

 the few cases of excitement after the inhalation of ether might 

 be attributed to the previous state of mind of the patient, or to 

 alcohol combined with it. Conclusions drawn from experiments 

 upon animals with these agents should be received with great 

 caution. Their action on animals differs according as they have 

 or have not a cutaneous perspiration. It kills those of the latter 

 class. Dr. Jackson recommended a mixture of chloroform with 

 alcohol, in the proportion of an eighth or a quarter of an ounce 

 of the former to four ounces of the latter. 



The President remarked that from his own experience he pre- 

 ferred ether to chloroform, as being much safer. He alluded 

 to the fatal cases that have been reported from the use of the 

 former, and said it was not easy to explain this result. He pre- 

 ferred, in his own practice, chloric ether to either of the other 

 anaesthetic agents. 



Mr. Desor said that he had lately observed among the 



