THE WONDERS OF LIFE 



to illustrate the limit of this transgressive growth by a 

 simple physical example, Ostwald imagines a ball placed 

 in a small flat basin, built up high on one side. The 

 ball is in a state of equilibrium in the basin; when it is 

 lightly pushed aside it always returns to its original 

 position. But when the push goes beyond a certain 

 point, and the ball is thrust over the side of the basin, 

 the balance is lost; the ball does not return, but falls to 

 the ground. The crystal behaves just in the same way 

 in a supersaturated solution when it exercises its power 

 of forming new crystals; and it is just the same with 

 the bacterium growing in a nutritive fluid when it 

 passes the limit of its volume of growth, and divides 

 into two individuals. 



As we can find no morphological and little physiological 

 difference between the living and non-living, we must 

 look upon metabolism as the chief characteristic of or- 

 ganic life. This process causes the conversion of food into 

 plasm; it is determined by the vital force itself, and is 

 the formation of new living matter. It thus effects the 

 nutrition and growth of the living being, and therefore 

 its reproduction, which is merely transgressive growth. 

 As I shall describe this metabolism fully in the tenth 

 chapter, I will do no more here than emphasize the fact 

 that this vital process also has analogies in inorganic 

 chemistry, in the curious process of catalysis, especially 

 that form of it which we call fermentation. 



The distinguished chemist Berzelius discovered in 

 1 8 10 the remarkable fact that certain bodies, by their 

 mere presence, apart from their chemical affinity, set 

 other bodies in decomposition or composition without 

 being themselves affected. Thus, for instance, sulphuric 

 acid changes the starch in sugar without undergoing 

 any alteration itself. Finely ground platinum brought 

 in contact with hydrogen-superoxide divides it into 

 hydrogen and oxygen. Berzelius called this process 



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