Other Elements 19 



as a basis for the manufacture of commercial fertilizers. 

 All feeding stuffs in their natural forms contain phos- 

 phorus, either as phosphates, * or as combined in cer- 

 tain fats and nitrogen compounds which stand in close 

 relation to the vital processes. It is distributed in the 

 flesh of animals, and combined with lime constitutes a 

 large part of bone. 



Chlorine, which is a constituent of common salt, is 

 essential to the nutrition of the animal. At ordinary 

 temperatures it is, in the free state, a greenish -colored, 

 disagreeable gas. When combined with hydrogen it 

 forms hydrochloric acid, a compound which is necessary 

 to ths digestion of food. Any ordinary mixed ration 

 contains this element in a quantity sufficient for the 

 animal's needs. 



Potassium combined with oxygen and hydrogen 

 gives us the caustic potash of the market. The ashes 

 of all plants contain this element, a familiar illustra- 

 tion of this fact being the potassium carbonate leached 

 from wood ashes by hot water in the old-fashioned way 

 of making soft soap. The saleratus formerly used in 

 bread -making is a potassium compound. This element 

 is found in the flesh of animals, mostly in the form of 

 the phosphate, and is abundantly supplied for the pur- 

 poses of nutrition by all feeding stuffs that are not 

 by-products. 



Sodium is the basal element of common salt, and in 

 this form it is very generally supplied to domestic ani- 

 mals. In this connection, sodium chloride (common 

 salt) is about the only sodium compound we need to 

 mention, for this is the one that serves almost wholly 



*See note 1, p. 60. 



