NUTRITIVE VALUE OF AGRICULTURAL PRODUCE. 613 



It is not unlikely that turnips, raised from bones, will also abound more 

 largely in phosphates than turnips raised from dung or rape dust, and 

 may therefore be better fitted for growing stock. 



§ 15. Can we correctly estimate the relative feeding properties of different 

 kinds of produce under all circumstances. 



Since the several nutritive effects of different kinds of food are de- 

 pendent upon so many circumstances — upon the state of the animal 

 itself — the purpose for which it is fed — the mode in which it is housed 

 and protected — the form and period at which it is given— can it be pos- 

 sible to classify them in an order which will indicate their relative feed- 

 ing values in all cases and for all purposes ? This is obviously impos- 

 sible. We may easily arrange them in the order of their relative values 

 in reference to some one of the several purposes for which food is given. 

 We may shew in as many different tables the order of their relative 

 values in laying on fat — in increasing the muscles — or in promoting the 

 growth of bone ; but we cannot arrange theoretically, nor can experi- 

 ment ever practically classify, all our common vegetable productions in 

 one invariable order which shall truly represent their relative values in 

 reference to each of these three different points : — 



1°. Experimental values. — This, however, practical writers have often 

 attempted to do. Making their experiments in different circumstances, 

 with different varieties of the same produce, upon different kinds of 

 stock, or upon animals fed for different purposes, they have obtained re- 

 sults of the most diversified kind, and have classified the several kinds of 

 fodder in the most unlike order. I se'ect a few of these results for the sake 

 of illustration.. Taking 10 lbs. of meadow hay as a standard, — then, to 

 produce an equal nutritive effect, the different quantities of each of the 

 other kinds of fodder represented by the numbers in the following table 

 ought to be used — according to the several authors whose names are 

 given. 



Experimental quantities of fodder which must he used to produce an 

 equal nutritive effect^ according to — 



F^om an inspection of this table, we should naturally conclude eituer 

 26* 



