FURTHEK ADVANCES IN PHYSIOLOGY 



THE EQUILIBRIUM OF COLLOID AND 

 CRYSTALLOID IN LIVING CELLS 



BY BENJAMIN MOORE 



THE living cell may be regarded from the physico-chemical point 

 of view as a machine or mechanism through which there constantly 

 is taking place a flux of energy. The cell is continually taking 

 energy up from its surroundings in certain forms, and redistribut- 

 ing this energy in other forms, but in the process it itself under- 

 goes little or no permanent change. Certain changes, it is true, 

 do occur slowly in the cell in the course of its life -history which 

 have the effect of permanently altering the character of the energy 

 discharged through it ; but these structural changes are so slow that 

 they can be put aside in the study of the cell as an energy machine 

 acting upon the energy supply at any given moment. 



If the case of the green plant cell acting as an energy trans- 

 former for light energy be placed on one side, it may be stated that 

 the energy supplies of the cell always come to it in the form of 

 organic compounds capable of yielding energy in the process of 

 oxidation in the cell. 



In order that the cell may be capable of oxidising these 

 chemical compounds of organic character coming in from its 

 environment, it is, however, absolutely essential that its own in- 

 tegrity be preserved ; and this integrity is just as completely de- 

 pendent upon the presence of the ions of certain simple inorganic 

 salts in the cell and its surrounding fluid media, as the exhibition 

 of the typical phenomena of cell activity is upon the supply of 

 energy in the form of the organic compounds to the living cell. 

 In fact, in point of time, the physiological activity of the cell is 

 more rapidly destroyed by removing or altering the supply of 



