LIPOID-ALTERANT SUBSTANCES 193 



according to the partition-ratios. Any tendency to 

 concentrate at surfaces (e.g., the general cell surface or 

 the surfaces of other hpoid-containing protoplasmic 

 structures) would be favorable to such solution; i.e., 

 would render it more rapid and greater in degree than 

 it would be otherwise, since the partition-equilibrium 

 would then be between the solution in contact with the 

 surface of the lipoid particle and the solution in the 

 interior of the particle. 



Meyer's experiments on the influence of temperature 

 on the critical anaesthetizing concentrations of certain 

 compounds^ gave further indications that the solubility 

 of these compounds in the cell-lipoids is the essential 

 factor in the physiological effect. He chose six com- 

 pounds whose oil-water partition-ratios vary considerably 

 with temperature, and determined the minimal concen- 

 trations required to anaesthetize tadpoles at the two 

 temperatures 3° and 30°. These concentrations are 

 given in the following table : 



An^cfViofi^ Critical Concentration Oil-Water Partition- 



Ansestnetic ^^^ Anaesthesia Coefficients 



At 3° At 30° At 3° Atao" 



(A) Salicylamide m/1300 m/600 22.23 ^4 



Benzamide m/soo m/200 0.67 0.43 



Monoacetin m/90 m/70 0.099 0.066 



(B) Ethyl Alcohol m/3 m/7 0.026 0.247 



Chloral Hydrate. . . m/50 m/250^ oo53 0.236 



Acetone m/3 m/7 o. 146 o. 235 



In the first three compounds (A) the relative Hpoid- 

 solubiHty decreases with rise of temperature, and the 



^ Meyer, Arch. f. exper. Path. u. PharmakoL, XL VI (1901), 3'38. 

 Recently Mary E. Collett has investigated the effects of variation of 

 temperature on the narcotic action of various compounds on marine 

 organisms; cf. Proceedings of the Society for Experimental Biology and 

 Medicine, XX (1923), 259. 



