CONSTITUENTS OF BUTTER. 389 



young grass, which will also satisfy a cow. That one 

 hundred pounds of young grass will yield more butter, 

 will scarcely admit of a doubt. The t venty-eight 

 pounds of hay will be equal in' albuminous matter and 

 in oil to the one hundred pounds of grass ; but in the 

 element of starch, sugar, etc., there is a marked differ- 

 ence. During the growth of the plant, the starch and 

 sugar are converted into woody fibre, in which form 

 they are scarcely digestible or available for respiration. 

 It seems, then, not improbable that, when a cow is sup- 

 plied with hay only, she will consume some portion of 

 ihe oleine oil for respiration, and yield a less quantity 

 of butter poorer in oleine. 



If you assume summer butter to contain of oleine, . . 60 per cent 

 " " " " " •' " of margarine, 40 " " 



100 " " 

 If the cow consume of the oleine, 36 " " 



The quantity of butter will be reduced from 100 to . 64 " " 



And the proportions will then be, of oleine, . . . 40 " " 

 " " " " " " of margarine, . . 60 '* " 



100 " " 



If you supply turnips or mangel with hay, the cow 

 will consume less of hay ; you thereby substitute a 

 material richer in sugar, etc., and poorer in oil. Each 

 of these materials, in the quantity a cow can consume, 

 is deficient in the supply of albumen necessary to keep 

 up the condition of an animal giving a full yield of 

 milk. To effect this, recourse must be had to artificial 

 or concentrated substances of food, rich in albuminous 

 matter. 



It can scarcely be expected, nor is it desirable, that 

 practical farmers should apply themselves to the attain- 

 ment of proficiency in the art of chemical investiga- 

 tions ; this is more properly the occupation of the pro- 

 fessor of science. The following simple experiment, 

 however, seems worth mentioning. On several occa- 

 sions, during winter, I procured samples of butter from 

 my next neighbor. On placing these, with a like quan- 

 tity of my own, in juxtaposition before the fire, my 

 33* 



