FEEDING 
analyze the substances of the fresh material. The answer is 
that he doesn’t know how. Progress is made every year but 
the whole subject is yet too much clouded in obscurity to be of 
any practical application. At present the feeding of mineral 
substance, like the feeding of protein, can best be learned by 
experimenting directly with the foods rather than by attempt- 
ing to go by their chemical composition. 
In practice it is found that green feed supplies something 
which grain lacks, presumably mineral salts. Moreover we 
know that such food fed fresh is superior to the same sub- 
stance dried. This may be because of chemical changes that 
occur in curing or simply because of greater palatability. 
The other chief source of mineral matter is meat prepara- 
tions with or without ground bone. Recent experiments at 
Rhode Island have attempted to show the relative value of the 
mineral constituents of meat by adding bone ash to vegetable 
proteids, as linseed and gluten meal. The results clearly in- 
dicate that mineral matter of animal origin greatly improves 
the value of the vegetable diet, but that the latter is still 
sadly deficient. Of course the burning process used in prepar- 
ing the bone ash may have destroyed some of the valuable 
qualities of the mineral salts. Practically, we do not care 
whether the value of animal meal be due to protein, mineral 
salts or both. 
In time the world will become so thickly populated that we 
cannot afford to rear cattle and condemn a portion of the car- 
eass to go through another life cytle before human consump- 
tion. By that time the necessary food salts will doubtless be 
known and we will be able to medicate our corn and alfalfa 
ana do away with the beef scrap. The poultrymen will do well, 
however, not to count on the chemistry of the future, for the 
chemist that makes the “tissue salts” for the hen may manu- 
facture human food with Niagara power and fresh eggs will 
come in tin cans. 
How the Hen Unbalances Balanced Rations. 
Let the poultryman who figures the nutritious ratio of 
chicken feed try this simple ex: eriment. Place before a half 
dozen newly hatched chicks a feed of one of the commercial 
chick feeds. When they have had their fill, sacrifice these 
innocents on the altar of science and open their crops. He 
will find that one chick has eaten almost exclusively of millet 
seed, another has preferred cracked corn, another has filled up 
heavily on bits of beef scrap and mica crystal grit, while a 
fourth fancied oats and granulated bone. In short the chick 
has, in three minutes, unbalanced the balanced ration that it 
104 
