2o6 PROTOPLASMIC ACTION AND NERVOUS ACTION 



effect is secondary to some physical modification pro- 

 duced in the protoplasm by the narcotizing compound.^ 



PHYSICAL CHANGES PRODUCED BY LIPOHD-SOLVENT 

 COMPOUNDS IN PROTOPLASM 



Certain definite changes in the physical properties of 

 protoplasm, analogous in many respects with those 

 produced by salts, have been observed in various cases 

 to accompany the action of narcotizing compounds; 

 these changes indicate that underlying narcosis there 

 are definite modifications of the structural conditions in 

 protoplasm; and presumably it is to such modifications 

 that the changes in physiological properties and activity 

 are to be referred. As we have seen, the distinctively 

 vital processes are controlled by structural conditions; 

 structural change impHes physiological change. 



' For a more detailed discussion of the relation of narcosis to oxida- 

 tion processes see my review, "The Theory of Anaesthesia" {Biological 

 Bulletin, XXX (1916), 311, also American Yearbook of Anesthesia, I, i). 



According to Warburg (cf . his recent article on the physical chemistry 

 of cell-respiration, Biochem. Zeitschrift, CXIX [1921], 134) the proto- 

 plasmic oxidations occur at the surface of the solid cell structures, which 

 adsorb the water-soluble oxidizable compounds; narcotics influence 

 oxidations by changing the physical and chemical character of the surfaces. 



He expresses his general conclusions on the conditions of proto- 

 plasmic oxidations as follows: "Two chief means are employed by the 

 cell to diminish the chemical resistance at the regions of oxidation; 

 namely, adsorption and the catalytic action of heavy metals .... Cell 

 respiration is a capillary process occurring at the iron-containing surfaces 

 of the solid cell-constituents. By adsorption at these surfaces the inert 

 organic compounds become capable of reacting with O2 just as do amino- 

 acids at the surface of charcoal. This view does not explain respiration 

 in the physical sense, but classes it with general phenomena of the 



inorganic world Narcotics check the cell-oxidations by occupying 



the surfaces and thereby displacing the oxidizable compounds. The same 

 action is exhibited by different narcotics when the same fraction of the 

 active surface is occupied by the narcotic" (pp. 152, 153). 



