336 RALPH S. LILLIE. 



than the increase in capillary activity. The influence of the 

 H-ion concentration enters here, and probably constitutes the 

 preponderant factor. The part played by purely chemical action 

 seems to be underestimated in Traube's theory. Where this 

 factor enters, surface-activity may be of subordinate importance. 

 Thus in the case of neutral salts solutions of equal surface-ten- 

 sions may have entirely different action on colloids and hence 

 on living cells. Traube's rule is at best an approximation; but 

 its significance is not to be underestimated on this account. 

 Adsorption and surface-condensation undoubtedly run parallel 

 with capillary activity; this is a matter not only of deduction 

 from the Gibbs-Thomson principle, but also of direct observation; 

 and surface-forces play so large a part in biological processes 

 that it is not surprising to find a frequent parallelism between 

 the physiological effects of solutions and their surface-activity. 



Traube in fact recognizes that the lipoid-content of cells may 

 have an influence on the rapidity of intake of the narcotic 

 (since lipoid-solubility will naturally favor penetration), and 

 hence may be a factor in the narcotic action; but the narcosis 

 itself does not depend on this solution in lipoids; "the lipoid- 

 content influences narcotic action but does not determine it; 

 even lipoid-free cells may be narcotized." 1 This conception, 

 however, does not seem adequate in view of the observations of 

 Meyer cited above, on variation of narcotic action with tempera- 

 ture. 



It is important to note that surface-active substances affect 

 not only biological processes but also catalyses of various kinds, 

 especially those due to enzymes and other colloidal catalyzers 

 (platinum, etc.), where the action is probably dependent on the 

 character and extent of the surface between catalytic agent and 

 medium (heterogeneous catalyses). Enzymes are colloidal cata- 

 lyzers formed in cell-metabolism; as colloids it is to be expected 

 that surface-conditions will largely influence their action. Re- 

 cently Bayliss 2 has emphasized the importance of such conditions. 



1 "Theorie der Narkose," loc. cit., p. 305. 



2 Cf. Bayliss, "The Physiological Importance of Phase-boundaries," Science, 

 N. S., 1915, Vol. 42, p. 509. For the influence of anaesthetics on invertase and on 

 colloidal platinum, of. Meyerhof, Pfliigcr's Archiv, 1914, Vol. 157, pp. 251, 307; 

 cf. also Warburg, ibid.. Vol. 155, p. 547, for their influence on the catalytic activity 

 of finely divided carbon (animal charcoal). 



