THE PROCESSES OF DEPRESSION 253 



by typical strychnine tetanus. If a nerve is placed in a gas cham- 

 ber through which a mixture of nitrogen and ether is allowed to 

 flow until irritability is greatly decreased, and is then displaced 

 by pure nitrogen, irritability increases more or less completely 

 according to the time which has passed from the beginning of 

 asphyxiation. This investigation proves that living substance, 

 even after the deepest narcotic depression, may recover on ces- 

 sation of the narcosis, although in an entirely oxygen-free medium. 

 Frohlich, Botidy and Heat on, by the methods of their experi- 

 ments above described, have proved this fact in a great number 

 of instances. On the other hand, Ishikawa could not observe 

 a pronounced recovery in amoebae from narcosis in pure nitrogen. 

 But it is possible that here the difference is perhaps merely 

 quantitative. 



What position should be taken in the face of these facts ? Does 

 recovery of a deeply narcotized tissue in an oxygen-free medium 

 really make it difficult to suppose that narcosis is the result of 

 an acute suppression of the processes of oxydation? On closer 

 view, it will be found that this difficulty is merely apparent. In 

 reality it is quite possible to bring these facts into harmony with 

 the assumption that narcosis consists in a suppression of these 

 processes. If one proceeds from the supposition that living sub- 

 stance possesses a certain, even though merely a small supply of 

 oxygen in its interior, then it is at once evident that a more or 

 less complete recovery of irritability from narcosis depression is 

 possible, even in an oxygen-free medium. It can take place at 

 the cost of the oxygen still present in the living substance and 

 which during the narcosis, on account of the suppression of the 

 oxydation processes, could not be consumed. If the presence of 

 a certain oxygen reserve in living substance is entirely set aside 

 and a different explanation sought for the primary continuance 

 of irritability after a complete withdrawal of the oxygen supply 

 from without, the great difference of time in the setting in of the 

 depression in narcosis and that of the complete elimination of the 

 oxygen supply from without would make it necessary to assume 

 the processes occurring in narcosis are entirely different in nature. 

 The explanation that narcosis is the result of suppression of the 



