THIRTY CENT BREAD 57 



trol of the chemical reaction of the blood and tissues 

 they govern enzyme action. 



"They unite with injurious products of metabo- 

 lism, and render them harmless or useful. 



"As catalyzers they alter the speed of reactions, 

 and the rate of metabolism generally, as measured 

 by oxygen consumption. 



"Through their effects on surface tension they 

 participate in the mechanism of cell movement. 



"Through their control of the imbibition of water 

 by the colloids they govern absorption and secretion. 



"Through their control of the affinity of the blood 

 for gases they govern respiration. 



"Finally, they control the state of solution, precipi- 

 tation, mechanical aggregation, chemical association 

 and ionization of the colloids which compose living 

 tissue. 



"These then are some of the functions of the 

 mineral elements. Considering their nature and 

 importance, it is at once obvious that life could not 

 endure if its complex mineral requirements were 

 not automatically and constantly maintained in 

 almost perfect adjustment. 



"What then are the facts which warrant the prac- 

 tical consideration of this subject? 



"They are that in pathological states these func- 

 tions are somewhat deranged, and that life as we 

 live it is in many respects highly abnormal, in the 

 sense of dififering from that to which human metabo- 

 lism is attuned; and with our ever-increasing social 

 differentiation life puts increasing stress upon the 

 integrity of the body and its normal processes. 



"In relation to food niaterials there are also im- 

 portant facts bearing on this matter of the mineral 



