LIPOID-ALTERANT SUBSTANCES 197 



than by solution in the Hpoids has been supported by 

 many recent investigators, especially Czapek, Traube, 

 and Warburg/ 



The general fact that the physiological action 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 : 



Ai^^T,^! Volumes 



^I'^^^o^ (per cent) 



CH3OH 20 



aHsOH 15 



C3H70H 10 



C4H9OH 2.5 



CsH„OH I 



C6HX3OH 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 Plasmahaui, Jena (191 1) ; Traube, 

 "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. 



2 Richardson, "Physiological Researches on Alcohols," Medical 

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



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

 Wiesel obtained similar results with the series of ure thanes {loc. cit.). 



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

 ences in the papers cited above. 



