COMPARISON OF ETHER WITH CHLOROFORM 



283 



the last stage, narcosis, or poisoning, is beginning, and there 

 itj depression of the three great medullary centres, controlling 

 the heart, respiration and vascular tension, and also the 

 lowest reflex centres of the cord, so that the urine and faeces 

 are passed involuntarily. Micturition frequently occurs in 

 the first stages of anaesthesia and should not of itself be con- 

 sidered a danger signal. The pulse becomes rapid, feeble 

 Mud irregular ; the breathing is at first stertorous, and then 

 the respiratory movements become shallow and weak, with 

 considerable intervals intervening between them. The 

 pupils are often dilated. The pupil is said to be a guide 

 during anaesthesia, especially with chloroform, since it is 

 contracted during the anaesthetic stage and dilates quickly 

 when danger approaches. Death, however, occurs in animals 

 with either dilated or contracted pupils. With the former, 

 probably from asphyxia ; with the latter, from syncope ; and 

 the pupil should not be regarded as an unfailing sign. The 

 foregoing stages are conventional, and are not in any case 

 so clearly defined in practice as they are described theoreti- 

 cally upon paper. The first stage may be either absent or 

 prolonged, and the last stage should not be reached at all. 



COMPARISON OF ETHER WITH CHLOROFORM. 



ETHER. 



More diffusible. 



Inflammable. 



Irritating ; may induce bronchitis 

 and nephritis. 



Administered slightly diluted with 

 air. 



Stimulant to heart, except in enor- 

 mous quantities. 



Stimulant to vasomotor centres, 

 except as above. 



Respiratory centres not so easily 

 depressed as by chloroform. 



Larger quantity required. 



Less rapid: stage of struggling 

 and excitement longer. 



More expensive. 



Fatal from respiratory failure. 



CHLOROFORM. 



Vapor heavier. 



Less irritating. 



Not inflammable. 



More danger from shock during 

 imperfect anaesthesia. 



Depresses powerfully, heart, res- 

 piratory and vasoiiioter centres 

 in large doses. 



Acts more quickly, profoundly, 

 and persistently. 



Smaller quantity required. 



Cheaper. 



Proportion of deaths to inhala- 

 tions, 4 to 5 times greater than 

 with ether. <* 



Death occurs from respiratory fail- 

 ure combined with circulatory 

 depression. 



Occasionally fatality results from 

 syncope. 



