ORIGIN OF LIFE, SEX, SPECIES, ETC. 213 



force and direction of chemical affinities, whether 

 these originate within or without the masses of 

 which they are parts. 



From instant to instant the movements within 

 each aggregate produce innumerable differences 

 in the distribution, locality, and distances between 

 the atoms, molecules, etc., within them, and there- 

 fore in the force and direction of the affinities and 

 repulsions exercised between them. The universal 

 commotion does the same for the environing atoms, 

 molecules, masses, etc. ; and since these two, the 

 separate and the universal, motions continuously 

 interact with each other, therefore must the in- 

 finitely great tendency to enter into new combina- 

 tions and to break away from the old, experience 

 infinite multiplication from moment to moment. 

 This tendency is limited, however, by the power 

 which originates it, viz., the sum total of all internal 

 and external affinities and repulsions which act on 

 any separate unit. 



So long as these new and old combinations re- 

 tain within certain limitations of quantitative 

 variability the essential properties of living sub- 

 stance, so long may they be classified as such. 



When, as for instance in ivory or mother of pearl, 

 through the quantitative predominance of carbon 

 and of the secondary elements of life, the mobility 

 for purposes of chemical changes or interior motions 

 is almost nil, or when, as for instance in swamp gas 

 or ammonia, sulphureted hydrogen, etc., the exces- 



