PHYSICAL FORCES INVOLVED IN BIOLOGICAL ACTIVITIES 185 



When food is prepared it is probably in the form of a molecular or 

 ionic dispersoid which enters the substance of the protoplasm and 

 diffuses readily. The ionization of the cell is, according to many 

 authorities, dependent upon the ionic or molecular dispersoids which 

 are found in the cell substance, whether they are on their way to become 

 protoplasm or are the products of cell activity. When these ionic or 

 molecular dispersoids of the cell are of a nature and possess the affinity 

 to attach themselves to molecules of protoplasmic structure, their 

 diffusibility is lost and they become anchored; if, however, there exist 

 diffusible substances which are cast off from the protoplasmic molecules 

 by metabolic action and no longer possess the affinity for attaching 

 themselves, their dissipation by elimination is assured. The change of 

 starch, glycogen, protein, as food, to diffusible products by regulation 

 digestive processes and the elimination, as waste products, of diffusible 

 substances have a tendency to confirm this vital interpretation. 



Literature freely consulted and recommended for extended study. 



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CLARK, W. M., The Determination of Hydrogen Ions, 1920. 



HATSCHEK, Colloids. 



HOBER, Physikalische Chemie der Zelle und der Gewebe. 



ITANO, The Relation of Hydrogen Ion Concentration of Media to the Proteolytic 



Activity of B. subtilis. 

 JONES, Nature of Solutions. 

 KIMBALL, College Physics. 



MACLEOD, Physiology and Biochemistry in Modern Medicine. 

 McCLENDON, Physical Chemistry of Vital Phenomena. 

 MICHAELIS, L., Die Wasserstoffionenkonzentration. 

 NICHOLS and FRANKLIN, The Elements of Physics. 

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SORENSEN, S. P. L., Ergebnisse d. Physiologic, Bd. 12, 1912. 

 VON PROWAZEK, Physiologie der Einzelligen. 

 THOMSON, The Corpuscular Theory of Matter. 

 THOMSON, Rays of Positive Electricity. 

 WALKER, Introduction to Physical Chemistry. 

 WASHBURN, Principles of Physical Chemistry. 

 WELLS, Chemical Pathology. 



