CHAPTER I 



THE NUTRIENT CONTENTS, PALATABLE NESS, AND 

 DURABILITY OF THE FEEDING-STUFFS. 



ONLY those materials can be accounted food- 

 stuffs that contain organic or mineral nutrients 

 in a form which can be utilised and which, within 

 the usual limits of practice, have no injurious 

 action. 



Indigestible materials, such as peat, ground 

 leather, powdered coal, sand, earth, etc., or poison- 

 ous substances like castor-oil seed meal, poppy 

 seeds, poisonous plants, etc., further such sub- 

 stances as contain injurious bacteria, are not food 

 materials. 



Amongst the properties which determine the 

 value of a feeding-stuff the first place is taken by 

 the variety, quality, and action of the digestible 

 nutrients. 



A glance at Table I, in the Appendix, will show 

 that great differences exist. There is only one way 

 in which information regarding these properties can 

 be obtained, and that is by a chemical and micro- 



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