CHAPTER VII 
FEEDING 
The old adage that a little knowledge is a dangerous thing 
is nowhere better illustrated than in the scientific phases of 
poultry feeding. The attempted application of the common 
theoretical feeding standards to poultry has caused not only a 
great waste of time but has also resulted in expenditures for 
high-priced feeds when cheaper feeds would have given as 
good or better results. 
The so-called science of food chemistry is really a rough ap- 
proximation of things about which the actual facts are un- 
known. Such knowledge bears the same relation to accurate 
science as the maps of America drawn by the early explorers 
do to a modern atlas. Like these early efforts of geography 
the present science of food chemistry is all right if we realize 
its incompleteness. In practice, the pouliryman, after a gen- 
eral glance at the “map,” will find a more reliable guide in 
simpler things. 
I am writing this book for the poultryman, not the professor, 
and because I state that the particular kind of science wherein 
the professor has taken the most pains to teach the poultry- 
man is comparatively useless, I fear it may arouse a mistrust 
of the value of science as a whole. I know of no way to pre- 
vent this except to point out the distinction between scientific 
facts and guesses couched in scientific language. 
When a scientist states that a hen cannot lay egg shells 
containing calcium without having calcium in her food, that 
is a fact, and it works out in practice, for calcium is an ele- 
ment, and the hen cannot create elementary substances. When 
the same scientist, finding that an egg contains protein, says 
that wheat is a better egg food than corn because it has the. 
largest amount of protein, that is a guess and does not work 
in practice because protein is not a definite substance, but the 
name of a group of substances of which the scientist does not 
know the composition, and which may or may not be of equal 
use to the hen in the formation of eggs. 
All substances of which the world is made are composed of 
elements which cannot be changed. When these elements are 
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