224 SCIENTIFIC FEEDING OF ANIMALS 



average 37-38 % of phosphoric acid is obtained. 

 This powder is the phosphate of lime used for 

 feeding purposes, in which 90 % of the phosphoric 

 acid ought to be soluble in ammonium citrate. The 

 phosphate of lime is valued according to its content 

 of citrate-soluble phosphoric acid. Often the pro- 

 duct is very damp, and therefore less valuable ; 

 sometimes in it are found dangerous quantities of 

 arsenic, soluble calcium salts, or sulphurous acid, 

 which latter is now used in some places instead of 

 hydrochloric acid for dissolving out the mineral 

 matter from the bones. It is necessary to be 

 cautious in buying phosphate of lime for feeding 

 purposes, for not seldom less valuable materials, 

 such as bone meal or bone ash, are sold, instead of 

 the precipitated phosphate of lime. The phosphoric 

 acid in the last product can be utilised to the extent 

 of 50-60 %, whereas the animal is not able to 

 assimilate more than 13-14 % of the phosphoric 

 acid in the two former products. 



(n) Cattle powders. 



In spite of the many scientific investigations 

 which have been carried out on the nutrition 

 of animals, no means have yet been discovered 

 whereby the digestive power of a healthy animal 

 can be increased or its ability to produce flesh 

 augmented. The failure of competent men to 



