226 PRINCIPLES OF VETERINARY SURGERY 



supervening the inhalation of the vapor was due to arrested 

 hsematosis. That is, the anaesthetic state was supposed to 

 depend upon the intoxication of the blood with carbonic 

 acid. This theory was, however, very short-Hved, as the 

 phenomena attending the accumulation of CO2 in the blood 

 and that accompanying the inhalation of an anaesthetic 

 possess nothing in common. The action of narcotics gen- 

 erally cannot be applied to anaesthetics, because of the 

 rnarkedly transient efifect of the latter. If a body is nar- 

 cotized with alcohol, opium, belladonna, etc., the dimin- 

 ished sensibility is lasting and it is never so regular, rapid 

 nor effectual as the state of anaesthesia. The total suspen- 

 sion of all consciousness, all sensibility and the diminution 

 of all the vital forces to the point of almost destroying Hfe, 

 accomplished in a few moments, and then as promptly 

 banished by a few breaths of air, is a phenomenon that is 

 as difificult to comprehend as to explain. 



The theory most generally accep^ted today, and which 

 seems to have been substantiated, in part, by experiments, 

 is that inhaled anaesthetics produce a transient alteration 

 of the protoplasm of the living cells. Claude Bernard and 

 Dubois go still farther by insisting that the alteration con- 

 sists of a dehydration of the protoplasm, which temporarily 

 suspends its activity. They compare their action on cells with 

 that of water applied to certain infusoria, which remain 

 dormant when dried but promptly become active in the 

 presence of moisture. In these low forms the dormant 

 state and the active state can be produced at will by alter- 

 nate desiccation and hydration. The effect is prompt and 

 regular and simulates the effect of inhaled anaesthetics. It 

 has been shown that all living cells are susceptible to the 

 action of anaesthetics, and that the sensibility to them 

 varies with their sensibility in general. That is, the higher 

 the order the more sensible is the cell to the influence. It 



