996 THE COMPLETE GRAZIER. BOOK x. 



added, is roughly taken into account in the mode of calculation now 

 described. 



The reader is supposed to have before him, the ordinary chemical 

 analyses of the feeding stuffs which he wishes to compare. The items 

 of moisture, indigestible woody fibre, and ash he ignores for the 

 moment though these sometimes affect variously the question of 

 condition or mechanical suitability when they are abnormal ; but here 

 we assume that the foods are normal and of good quality. He then 

 takes the percentage of oil and the percentage of albuminoids, and 

 adds them together and multiplies the total by 2|. To this he adds 

 the percentage of " mucilage, sugar, starch and digestible fibre." The 

 total roughly represents the relative value of the food in what for the 

 time we may call " food units." 



Let us as an example compare an average sample of linseed cake 

 with an average sample of wheat, taking the analytical figures given on 

 page 986. We there find as follows : 



Linseed Cake. Wheat. 



Oil or fat 11'4 1'8 



Albuminoids 25 '4 10 '2 



Starch, mucilage, sugar, &c. . . . 35 '8 71 '6 



Adding together the fat and albuminoids and multiplying by 2| we 

 get: 



Linseed Cake. Wheat 



11-4 1-8 



25-4 10-2 



36-8 12-0 



21 21 



73-6 240 



18-4 6-0 



92-0 30-0 



Add starch, &c. . . . 35 '8 71 '6 



Total food units . . . 127 '8 101 "6 



The value of the two foods in food units (including manure value) is 

 therefore roughly as 128 to 102. Now let us assume that the cost of 

 the linseed cake is 8 per ton, and that of the wheat 7 per ton. 

 Then in a ton of cake costing 8 we get 128 "food units," and in a 

 ton of wheat costing 7, we get 102 food units. In other words each 

 1 spent in cake (at the price per ton named) buys 16 " food units," 

 while each 1 spent in wheat (at the price per ton named) buys 14| 

 units. The cake, therefore, is, under the particular circumstances 

 assumed, the cheaper food. 



The possible error of such a valuation is much diminished when 

 foods of the same class are compared, and it will be found very useful 

 for comparing different specimens, say, of linseed cake, in order to see 

 which is the more economical to buy for it often happens that cakes 

 containing widely different percentages of oil and albuminoids are sold 

 at prices bearing little relation to their respective composition. 



