﻿iqi6] OSTERHOUT— PERMEABILITY 157 



to produce anesthesia, 10 being least for chloral hydrate and largest 

 for alcohol. 



On the other hand, the increase of permeability (except in the 

 case of alcohol, within certain limits) produces permanent injury 

 and is not reversible. It cannot be regarded, therefore, as the 

 characteristic effect of the anesthetic. The characteristic effect 

 must be regarded as in some way connected with decrease of per- 

 meability. 



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 movement 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 in permeability may result in the decrease 

 of irritability, which is the characteristic effect of an anesthetic. 



These investigations are of interest in view of the fact that 

 Meyer's theory of anesthesia, which has found wide acceptance, 

 states that anesthesia is the result of an increase of permeability. 

 Meyer supposes that anesthetics act on the lipoids of the cell 

 in such a way that they become more permeable. 



On the other hand, Lillie 11 has developed a theory according 

 to which anesthetics act by rendering the plasma membrane more 

 refractory to changes of permeability either by decreasing its 

 permeability or in some other way. Lillie has observed that 

 anesthetics antagonize the action of NaCl. This, however, does 

 not by itself tell us anything regarding the action of anesthetics 

 on permeability under normal circumstances, as for example when 

 added to sea water. Lepecshkin," on the bases of plasmolytic 

 investigations, states that the entrance of dyes and of KN0 3 into 

 the cell is hindered by anesthetics, but this is disputed by Ruhlaxd." 



Since the announcement of the writer's investigations, 2 similar 

 experiments have been undertaken in Hober's laboratory, with 



10 See, for example, the recent investigations of V. Korosy, Zeit. Physik. Chemie 

 93:145- I9I4- He finds that the reversible action of chloroform on ceil division in 

 fish embryos and photosynthesis in Elodea is confined to practically the same con- 

 centrations as those which produce reversible effects in the permeability of Laminaria 



