216 PHYSICAL BASIS OF CIVILIZATION 



confined within comparatively narrow limits as to 

 proportions and qualities follows, because, when- 

 ever the fixity goes beyond a certain limit, then that 

 process of unbalancing and balancing from instant 

 to instant, on which the maintenance of the mov- 

 ing equilibrium of life depends, must come to an end. 

 But when at the opposite extreme, the pent-up and 

 actual motions, exceed the force of the sum total of 

 attractive affinities operating on the atoms, mole- 

 cules, and concentrations of a mass or portion of 

 living substance, then it breaks up and the freed 

 atoms and molecules form less complex and more 

 stable compounds, which are then not suitable for 

 life. 



The nature of assimilation next claims attention. 

 By this process the suitable portions of any ma- 

 terials coming into contact with living substances 

 are first transformed by them into compounds 

 similar to the transforming ones, and then annexed 

 to them. This process evidently is only possible 

 when the balance of energy resides in the transform- 

 ing substances. 



Returning to the main line of argument : the last 

 thing mentioned was the mode of formation of the 

 very first protoplasmic masses on earth. Imme- 

 diately after their formation the particles within 

 these masses must have been in exceptionally 

 energetic motion; for the violent rushing toward 

 each other of the elementary atoms and compound 

 molecules, entering into these combinations, was 



