tain nitrogen ; they are of like composition with the caseine or curd 

 of milk and the lean meat of animals, and are important, since this 

 caseine, lean meat, and wool, hair and some other parts of the body must 

 be produced from this part of the food. The non-albuminoids include 

 starch, sugar, oil, fibre, etc. This part of the food can not take the 

 place of the albuminoids, since there is no nitrogen in any of the sub- 

 stances mentioned. In the feeding tables we have given the digesti- 

 ble constituents of all our foods, and there is a great variation in the 

 proportion of albuminoids to non-albuminoids ; this ratio is known 

 as the " nutritive ratio," and means simply the number of pounds of 

 starch, sugar and fat, i. e., non-albuminoids 1o one pound of albu- 

 minoids. We are told by the German feeders and investigators that 

 the proper "ratio" for a cow giving milk is 1 : 5.4, or that a cow 

 weighing 1,000 pounds needs daily 2.50 pounds of albuminoids and 

 •13.50 pounds of non-albuminoids ; and it is for us in the United 

 States to determine whether this amount and proportion of actual di- 

 gestible matter is best. We have now seen what milk is, have 

 glanced at the most plausible theory concerning its origin, and have 

 learned that food is composed of unlike parts. It remains for us to 

 see what effects follow from changing the kind or quality of food. 



HOW MAY WE EXPECT TO CHANGE THE QUALITY OF MILK? 



1st. Can we increase or decrease the per cent, of water? 



2d. Can we increase or decrease the per cent, of fat? 



There is much misunderstanding concerning the way in which milk. 

 is commonly believed to be changed in richness. Now, if we can in- 

 crease the per cent, of solids from thirteen per cent, to fourteen per 

 cent., then we have made the milk richer ; and yet the relative pro- 

 portion of fat, caseine and sugar in these solids need not vary. Again 

 the solids may remain unchanged, and, if by some method of feed- 

 ing, we can increase the per cent, of fat, then, so far as the butter- 

 maker is concerned we have a richer milk ; or, again, the solids might 

 increase and the fat in the solids decrease to such an extent that 

 there would be no change in the actual per cent, of fat in the milk. 

 To sum up, there are just two ways in which the per cent, of fat in 

 the milk may be increased : 1st, b}- decreasing the per cent, of water, 

 the ratio of fat, caseine and sugar in the solids remaining undis- 

 turbed ; 2d, by increasing the relative amount of fat in the solids, 

 the per cent, of water remaining unchanged. Of course a combina- 

 tion of these two methods might have the same effect. For ex- 

 ample, let us assume that we have a cow giving milk like the average 

 composition given on page four, and we will suppose that by some 

 method of feeding it is possible to decrease the water to eighty-six 

 per cent and increase the solids to fourteen per cent. Now we need 

 not have any change in the relative propeities of caseine sugar and 

 fat. Under these circumstances the analysis of such a milk would 

 be as in the following table, No. 2, or under the second method 



