IN LIVING MATTER 31 



ing concentration P B increases in a^ less ratio than does P A ; 

 conversely on dilution, P B decreases in a less ratio than P A , and 

 hence in dilute solutions P B increases relatively to P A . : 



In the case of a neutral fat or triglyceride hydrolysing in 

 solution, 2 three molecules of fatty acid and one of glycerine are 

 formed from each molecule of the fat, and the equation of equi- 

 librium becomes P B 4 = K . P A . Accordingly, the effect of con- 

 centration becomes still more accentuated, and the tendency is 

 still greater to form the fat in concentrated solution, and the 

 fatty acid and glycerine in dilute solution. Similar results follow 

 in the formation, or vice versd, of the starches and proteids from 

 their component simpler molecules. 



It follows from the above considerations that in order that 

 hydrolysis may proceed under the most favourable conditions, 

 as in digestion, that the reaction should proceed in dilute solution, 

 while in order that recombination may occur, as in storage in 

 the cell, the process should take place in concentrated solution. 

 Further, that any drop in concentration of a substance in solu- 

 tion in the cell will tend to produce again hydrolysis and re-solution 

 of the stored-up substance. In fact, on the supposition that .the 

 enzymes are not capable of utilising any other forms of energy 

 in the transformations which they induce, and merely act in 

 hastening passage to the equilibrium point, hydrolysis during 

 digestion, and building up again in the cell during metabolism 

 can only ^ proceed if the concentrations are low in digestion, 

 and high in the cell during metabolism and accompanying 

 storage. 



The truth of the law deduced theoretically above with regard 

 to the effect of concentration upon the point of equilibrium of 

 reactions can also be shown by experiments. Thus Croft Hill 



1 It may be pointed out that an electrolyte, such as sodium chloride in aqueous 

 solution, behaves similarly and for the same reason. In dilute solution, the 

 electrolyte is practically dissociated into its ions, while in concentrated solution 

 an amount proportional to the osmotic pressures of the different reacting sub- 

 stances is undissociated. The type of reaction is the same as that discussed 

 above. If at equilibrium, the osmotic pressure of the undissociated molecules 

 is represented by P s and that of each ion by P I} then as above for equilibrium we 

 have P s = K . P z 2 and the same reasoning as given above shows that PI increases 

 relatively to P s with increasing dilution. 



2 The neutral fats are practically insoluble in water, but the reasoning holds 

 for fats in solution in the cell protoplasm. (See p. H4.) 



