22 Causes and Course of Organic Evolution 



But even now, though heat was rapidly being absorbed as such, 

 and also modified as light, into the atoms, and so a cooling of 

 the surrounding surface regions was proceeding, the tempera- 

 ture probably ranged from 10,000° C. do\Mi to 4000° C. The 

 earth then appeared successively as a white, next as a yellow, 

 and later as a red star. 



But ^dth increasing absorption of intra-atomic energy over 

 the evolving crust, with resulting rapidity of atomic motion 

 and reduced amplitude of the field of movement between the 

 energized ether particles, there was next established an increased 

 viscosity, and so the possibility of intimate union of atoms 

 between themselves, to constitute molecules. The energy 

 resulting from this union represented in turn a still higher 

 and more perfect type than that of light, and so greatly higher 

 than that of heat, and is what we term chemical affinity. This 

 period would approximately correspond, in iVrldt's table already 

 given (p. 12), to his "crust-formation" and in part his "anhy- 

 drate" periods, and so may have extended over more than 100 

 millions of years. 



The next progressive stage in energy transformation and 

 molecular evolution seems to have been the electrical. Since 

 gases are bad conductors of electricity — theoretically non- 

 conductors in the complete absence of radio-active bodies — 

 the abundant formation and free transfer of it during the gase- 

 ous period of the earth would have been small. Only after 

 the liquid and specially the solid state w^as assumed would 

 pathways for its flow be easy, and atomic centers for storage 

 of it be appropriate. So the period of its increasing evolution 

 and transformation would extend from Arldt's crust-forming, 

 on to his inorganic, epoch. Much of this electricity may have 

 been derived from the more primitive type chemical energy, 

 owdng to the active chemical reactions proceeding between 

 metals and electrolytic substances; in part it may have con- 

 densed from light transformations, but not a little may have 

 been derived on the one hand from radiated internal heat 

 and on the other from absorbed solar radiations. During this 

 period, therefore, those extensive magneto-electric disturbances 



