68 SENESCENCE AND REJUVENESCENCE 



oxygen carriers of the cell incapable of activating the molecular 

 oxygen, and that the cell consequently asphyxiates. A. P. Mathews 

 and some others have maintained that the action of narcotics 

 upon the oxidations is direct and chemical, and Mathews has re- 

 cently suggested that the residual valences of narcotic substances 

 are responsible for their action. In this coimection it may be noted 

 that the temperature coefi&cient of the susceptibiUty of Planaria 

 to potassium cyanide and alcohol is of the same order of magnitude 

 as the usual temperature coefiScient of chemical reactions (Child, 

 '13a). This fact indicates that the susceptibility increases in the 

 same ratio as the rate of chemical reaction and therefore suggests 

 that the cyanide and alcohol act directly upon the metabolic reac- 

 tions or some of them. But this relation between the temperature 

 coefficients of susceptibiHty and the rate of chemical reaction can- 

 not be made the basis of positive conclusions because it is possibly 

 nothing more than a coincidence, or it may result from a complex 

 of factors which we cannot analyze. 



Within the last few years various investigators have recorded 

 results at variance with the Verworn theory of narcosis. Warburg 

 found that certain narcotics produced narcosis without decreasing 

 the oxygen consumption of the organism. Later Loeb and Waste- 

 neys reported very similar results. They found that in some forms 

 of narcosis the decrease in oxygen consumption was very sUght, 

 while in others it was much greater. With the cyanides particu- 

 larly, narcosis occurs only when oxygen consumption is greatly 

 reduced, while in alcohol narcosis the decrease in oxygen consump- 

 tion may be very sKght. Oxygen consumption is decreased in 

 all cases, however, if sufficiently high concentrations of the nar- 

 cotic are used. Kisch has concluded from certain experiments 

 on protozoa that while narcosis does decrease certain oxidations it 

 does not affect all. Winterstein has also found that in alcohol 

 narcosis of the spinal cord of the frog a slight increase rather than 

 a decrease in oxygen consumption may occur even when irritabihty 

 is completely lost; there is, however, no increase in oxygen con- 

 sumption with stimulation. 



Assuming that these results are correct and not due to unrecog- 

 nized technical or other sources of error, we are forced to conclude 



