56 THE ORIGIN AND EVOLUTION OF LIFE 



heat of the earth or of the sun, or of both the heat and light 

 of the sun. 



Finally, we observe that ionization is connected with the 

 radioactive elements, of which thus far only radium has been 

 detected in the organic compounds, although the others may 

 be present. 



Phosphorescence in plants and animals is treated by Loeb^ 

 and others as a form of radiant energy. While developed in a 

 number of living animals — including the typical glowworms in 

 which the phenomenon was first investigated by Faraday — the 

 living condition is not essential to it because phosphorescence 

 continues after death and may be produced in animals by 

 non-living material. Many organisms show phosphorescence 

 at comparatively low temperatures, yet the presence of free 

 oxygen appears to be necessary. 



In Rutherford's experiments on radioactive matter- he tells 

 us that in the phosphorescence caused by the approach of an 

 emanation of radium to zinc sulphate the atoms throw off the 

 alpha particles to the number of five billion each second, with 

 velocities of 10,000 miles a second; that the alpha particles in 

 their passage through air or other medium produce from the 

 neutral molecules a large number of negatively charged ions, 

 and that this ionization is readily measurable. 



Interaction or Coordination of the Properties of the 



Life Elements 



The actions and reactions of the life elements, which are 

 mainly contemporaneous, direct, and immediate, do not suffice 

 to form an organism. As soon as the grouping of chemical 

 elements reaches the stage of an organism interaction also be- 

 comes essential, for the chemical activities of one region of the 



^Loeb, Jacques, 1906, pp. 66-68. -Rutherford, Sir Ernest, 1915, p. 115. 



