50 The Feeding of Animals 



The blood contains a variety of mineral substances, 

 the chief of which is sodium chloride, or common 

 salt, although a minute amount of iron is present, 

 having a most important function. In the bile, soda 

 is abundant, combined mostly with the peculiar or- 

 ganic acids of this secretion. Chlorine is a constant 

 constituent of the gastric juice, its presence as chlor- 

 hydric acid being essential to digestion. The preceding 

 are some of the prominent facts concerning the inor- 

 ganic compounds of the animal body, but they are only 

 a brief suggestion of the knowledge which pertains to 

 this part of animal chemistry. 



NOTE 1. Recent studies by Hart and Patten demonstrate the 

 absence of inorganic phosphorus compounds in the grains. Straw, 

 and by-product feeding stuffs that have been submitted to fer- 

 mentations and other treatment, may contain appreciable amounts 

 of inorganic phosphorus. 



NOTE 2. Certain important elements of the ash, including 

 at least potassium, sodium, calcium and magnesium, sustain basic 

 relations to organic compounds in the plant and animal, but in 

 what proportions and to what extent we do not well understand. 



