988 THE COMPLETE GRAZIER. BOOK x. 



cakes, however, we notice that we have a different class of foods 

 specially rich in albuminoids or nitrogenous substances. These last- 

 named foods are, therefore, particularly valuable for raising the pro- 

 portion of albuminoids in a diet largely consisting of roots and straw 

 chaff, which are deficient in albuminoids. 



Reference has been already made to the variations in the composi- 

 tion of oil-cakes. These variations are those occurring in genuine 

 cakes. But other variations occur, due to the considerable and 

 deliberate adulteration or admixture of the oil seed with inferior 

 materials before crushing. Sometimes this, in the case of linseed- 

 cake, is due to the use of seed imported in a dirty condition, but very 

 frequently deliberate additions of linseed-screenings and various refuse 

 matters are made. The cakes thus produced are often sold as " oil- 

 cake " to avoid the penalties that might be legally incurred by calling 

 them "linseed-cake," but most farmers are in the habit of calling 

 linseed cake " oil-cake," and so do not detect the evasion. When, 

 therefore, linseed-cake is required the purchaser should stipulate for 

 its purity. 



Cotton-cakes also are sometimes adulterated, and, like linseed-cake, 

 should be bought subject to the test of analysis. 



It will have been seen that we have given only the total percentages 

 of the principal chemical ingredients contained in the foods tabulated, 

 without reference to the fact that all are not equally digestible. Many 

 experiments have been recorded showing the proportions of albuminoids, 

 oil, carbohydrates, &c., actually digested in different foods b}^ the same 

 animals under similar conditions, and also by different animals. Oxen, 

 sheep, horses, and pigs will digest different proportions of the same food. 

 But the subject is an exceedingly complicated one, because much must 

 depend upon the proportion of the food given, and upon the relation it 

 bears, physically as well as chemically, to the total rations of which it 

 forms a part, and also upon the health and temporary condition of the 

 animal. Any reader, however, who wishes to see an excellent summary 

 of the scientific work that has been done in this line of research, 

 will find it in Warington's " Chemistry of the Farm," previously 

 referred to. 



The relationship of the albuminoids to the other constituents of food 

 has been already spoken of, but the general sketch that has in this 

 chapter been attempted of the functions and properties of foods would 

 be very incomplete without a more detailed reference to this phase of 

 the subject, because much of the success of the practical feeder depends 

 upon how nearly, whether empirically or designedly, he complies with 

 certain conditions which Nature has laid down as indispensable to the 

 most successful feeding. In one direction, that of too liberal a 

 supply of albuminoids, the farmer may probably err with practical 

 impunity, but in the other direction that of insufficiency he may 

 not err without being, directly or indirectly, a loser. 



An able popular essay on "the albuminoid ratio" and its prac- 

 tical bearing was contributed by the late Professor Warington to the 

 " Live Stock Journal Almanac/' 1891. As nothing so concise and at 



