212 PROTOPLASMIC ACTION AND NERVOUS ACTION 



this action in a manner resembling that of an antagonistic 

 salt like CaCla. Clowes has shown that in the physical 

 drop-systems which he studied — alkaline NaCl solution 

 flowing from a stalagmometer through oil — anaesthetics 

 produce an effect closely comparable with that of CaCla; 

 both actions are to be referred to changes in the properties 

 of the interfacial films formed between the oil and the 

 aqueous solution.^ The presence of a compound (Ca 

 soap, or fat-solvent compound) which is more soluble 

 in the oil phase than in the water phase, modifies the 

 conditions at the boundary in the same manner in both 

 cases, and produces the same physical effect in the 

 system. The parallelisms observed by Clowes between 

 the biological and the physical phenomena may be 

 interpreted as indicating that the conditions in living 

 protoplasm are of a closely analogous kind. 



The foregoing effects of anaesthetics on the physical 

 properties of protoplasm do not, however, enable us to 

 decide whether the solvent action or the adsorbent 

 action is the chief factor in the narcotic effect, or whether 

 both are equally concerned. Certain widely general 

 biological phenomena do not appear to be entirely 

 consistent with Traube's theory that surface-activity is 

 the essential factor in all cases of narcosis. These are: 

 (i) the great differences observed between the narcotizing 

 concentrations of the same compound in different cells, 

 tissues, and organisms; (2) the fact that weak solutions 

 of many narcotic compounds have a sensitizing or 

 accelerating influence on many cell-processes;^ (3) the 



'Clowes, Journal of Physical Chemistry, XX (1916), 407; cf. 

 pp. 434 fif. 



* Cf. the instances cited in my review of the theory of anaesthesia 

 {Biological Bulletin, loc. cit.). 



