192 INJURY, RECOVERY, AND DEATH 



It is easy to see how a decrease of permeability to 

 ions must hinder the production and the transmission 

 of stimuli in so far as these are dependent on the move- 

 ment of ions in the tissues, and there is abundant 

 evidence that stimulation is always accompanied by such 

 movements of ions in the protoplasm. It seems clear, 

 therefore, that a decrease of permeability may result in 

 the decrease of irritability, which is the characteristic 

 effect of an anesthetic. 10 



These investigations are of interest in view of the 

 fact that a number of writers hold the view that anesthet- 

 ics increase permeability, while others believe that 

 anesthetics bring about a decrease of permeability. 11 It 

 appeared desirable to clear up this uncertainty as a 

 necessary step toward a satisfactory theory of anesthesia. 



In order to see whether these facts are generally true, 

 the scope of the investigation was widened to include a 

 variety of material. Similar results were obtained in 

 experiments on frog skin, 12 but the effect was much more 

 striking. The increase of resistance was greater and 

 occurred with lower concentrations. 13 With respect to 

 recovery, the same difference was found between alcohol, 

 on the one hand, and ether, chloroform, and chloral 

 hydrate on the other. 



10 It might be expected on this basis that substances which decrease 

 permeability, such as Ca, La, etc. would act as anesthetics. To what 

 extent this is the case must be decided by future investigation. 



11 Cf. Hober (1914) pp. 466, 597; Lillie (1912, A, B; 1913, A, B; 

 1916, 1918); Lepeschkin (1911); Ruhland (1912, A); Katz (1918), 

 Weinstein (1916). 



12 For technique see page 33. 



13 Cf. Osterhout (1919, C). 



