208 



SURFACES AND MEMBRANES 



posed expanded stage of a film membrane would conform to the demands 

 of polarity made upon it as the result of the mosaic of pores and its rela- 

 tively flexible molecular orientation. It would depend for its degree of 



TABLE V-ll 



Chemical Analyses op Sap Compared with Normal Sea Water 



1 Valonia macrophysa. 2 Halicystis Osterhoutii. 



Mean Ionic Content of Blood Expressed in 

 Per Cent and Milliequivalent 



By Courtesy of W. J. V. Osterhout [1936]. 

 * By Courtesy of P. M. Hald and A. J. Eisenman [1937]. 

 For effects and changes due to high altitude see D. B. Dill, J. H. Talbot, and W. V. Consolazio 

 119371. 



polarity on the relative concentration of adsorbed ions and polar mole- 

 cules at the two faces of the bounding film. A shrinkage of such an 

 expanded film would also more nearly orient the molecules to produce an 

 increase in the degree of polarity and at the same time decrease the size 

 and number of the pores of the mosaic. 



In this connection Osterhout has shown that isotonic calcium chloride 



