LIPOID-ALTERANT SUBSTANCES 197 



than by solution in the Hpoids has been supported by 

 many recent investigators, especially Czapek, Traubc, 

 and Warburg.^ 



The general fact that the physiological acticm of 

 homologous compounds increases progressively with 

 increase in molecular weight has long been noted. 

 Richardson,'' in 1869, in a study of the pharmacological 

 action of alcohols, called attention to this rule, which 

 applies also to the effects on lower organisms; thus, 

 according to Regnard,^ the first six alcohols have equal 

 effects in suppressing the growth of yeast in the 

 following concentrations: 



Alcohol Volumes 



(per cent) 



CH3OH 20 



GHsOH 15 



C3H7OH 10 



C4H9OH 2.5 



CsH.xOH I 



C6H13OH 0.2 



In a series of papers beginning in 1904, Traube has 

 directed special attention to the parallelism between 

 surface-activity and physiological action.'' For example, 



^ Czapek, Oberflachenspanmmg der Plasmahaul, Jena (igi i) ; Traul>c, 

 "Theorie der Narkose," Arch. ges. Physiol., CLIII (1913), 276; CLX 

 (1915), 501. Cf. also "Theorie des Haftdrucks und Lipoidtheorie," 

 Biochem. Z., LIV (1913), 305, and other papers there cited. Warburg, 

 see below. 



* Richardson, "Physiological Researches on Alcohols," Medical 

 Times and Gazette, VIII (1869) (cited from Czapek, loc. cii.). 



3Regnard, Compt. rend. Soc. Biol, X (1889), 124- Warburg and 

 Wiesel obtained similar results with the series of urcthancs {loc. (it.). 



4 Traube, Arch. ges. Physiol, CV (1904), 541, 559, further refer- 

 ences in the papers cited above. 



