FUNCTIONS OF LIFE ELEMENTS 



6i 



power of combustion.' Its ions are very important factors in 

 animal respiration and in gastric digestion.'- It is very active 

 in dissociating or separating oxygen from various compounds, 

 and through its affinity for oxygen forms water (H2O), the 

 principal constituent of protoplasm. 







Fig. 7. Hm>rogen Flocculi Surrounding a Group of Sun-Spots. 



The vortex structure is clearly shown. After Hale. From the Mount Wilson 



Observatory. 



Oxygen, like hydrogen, has an attractive power which brings 

 into the organism other elements useful in its various functions. 

 It makes up two- thirds of all animal tissue, as it makes up 

 one-half of the earth's crust. Besides these attractive and syn- 

 thetic functions, its great service is as an oxidizer in the release 

 of energy; it is thus always circulating in the tissues. Through 

 this it is involved in all heat production and in all mechanical 

 work, and affects cell division and growth.^ 



1 Henderson, Lawrence J., 1913, pp. 218, 239, 245. 



^ W. J. Gies. ^ Loeb, Jacques, 1906, p. 16. 



