102 ACTIONS OF NARCOTICS 



ity. But a certain number of studies are now available. 

 The rnore important of these are those of Jacobs and 

 Parpart (1937), Barlund (1938), and Davson (1940). 

 Barlund showed that ether tends to decrease cell per- 

 meability and that the decrease varies with the molecule 

 which is considered. The effect is never very large. 

 Jacobs and Parpart showed that butyl alcohol de- 

 creases permeability of the red cells of man, rat and rabbit 

 to glycerol, but increases the permeability of the red 

 cells of ox, sheep and dog to glycerol. Davson found 

 that various narcotics increased the permeability of cat red 

 cells to potassium and simultaneously decreased their 

 permeability to sodium. These and various other results 

 in the literature indicate that the effect on cell permea- 

 bility of a given narcotic is sometimes to decrease the 

 permeability, sometimes to increase it: the effect varies 

 from cell type to cell type, species to species, and mole- 

 cule to molecule. As the narcotic substances do not 

 display any common effect on cell permeability it seems 

 unlikely that the changes in permeability which they 

 may induce are often prominent as effective modes of 

 action in narcosis. 



7^ Traube's Theory of adsorption correct? Traube noted 

 that there is a close parallel between the effect of narcotic 

 substances on surface tension and the physiological effect 

 of the substances. As the number of CHg groups is in- 

 creased, so surface tension is reduced and narcotic activ- 



