102 LIBBIE H. HYMAN 



degree of susceptibility, or, conversely, a different degree of re- 

 sistance to the action of these substances. This will be especial- 

 ly true if the metabolic difference is one of rate, for those parts 

 in which metabolism is going on most rapidly must be most 

 susceptible to substances which stop metabolism; moreover, we 

 have no reason to assume that the fundamental metabolic 

 processes are different in kind along the axis of a simple organism. 

 The method is, therefore, within certain limits, specifically a 

 method for demonstrating differences in metabolic rate between 

 the parts of an organism, or between comparable organisms. 



Regarding the exact way in which substances containing the 

 cyanogen radical and anaesthetics act on protoplasm, there is 

 at present much difference of opinion. It would be fruitless 

 to review here the numerous theories which have been advanced 

 with regard to the action of anaesthetics (Gwathmey,'14, Chap. II) 

 among them probably the Verworn conception of anaesthesia 

 as an asphyxiation has been received with the most favor. The 

 most recent evidence does not, however, support this view. 

 Thus Loeb and Wasteneys ('13 a, '13 b) and Winterstein ('14) 

 have measured the oxygen consumption under anaesthesia, and 

 have found that narcosis may occur without any decrease in 

 oxygen consumption, or usually only a slight one, or even a 

 slight increase. Winterstein ('13, '14) also calls attention to 

 many other data leading to the conclusion that the depression of 

 oxidation is not the primary factor in the production of anaesthe- 

 sia, as Verworn maintains. On the other hand, Tashiro and 

 Adams ('14) have reported a decided decrease in CO2 production 

 in the anaesthetized nerve of the spider crab. Further experi- 

 mental work is much needed before any conclusion regarding 

 the nature of anaesthesia can be drawn. 



More agreement exists as to the effect of the cyanides on liv- 

 ing matter. Since the work of Geppert, it has been generally 

 accepted that the cyanides act by diminishing or inhibiting the 

 oxidation processes. Geppert ('89) showed that an animal 

 poisoned by hydrocyanic acid was consuming less than the usual 

 amount of oxygen, even though such an animal goes into violent 

 convulsions; and further, that the oxygen content of the venous 



