i7o POPULAR SCIENCE MONTHLY 



In this connection, Chas. W. Townsend, M.D., of the Boston Float- 

 ing Hospital, says: 



The quality of the fat of Jersey and Guernsey milk, aside from its quan- 

 tity, is in some infants a cause of digestive disturbance; I have many times 

 seen babies gain but slowly and show fatty stools on Jersey milk modifications, 

 even when the percentage of fat was low, while the same babies gained rapidly 

 and digested well the modifications having the same amount of fat, made with 

 the milk of Ayrshire, Holstein or common red cows. 



Since centrifugalization was introduced much more attention has 

 been given to breeds giving more rational milk, for the separator 

 removes as easily and at the same cost the fat from a low as a high 

 percentage milk. Hence, the effort as indicated has been to develop 

 breeds which would produce skimmed milk which was nutritious and 

 regarding the manifold virtues of which as a food we need not enter 

 into here. 



So highly developed are some of these breeds of the first class that 

 it is worthy of note that many individuals are to be found that will 

 give their weight of milk each month and total butter production for 

 the year, equivalent to one half their weight. 



Hence, we find in breeds representing the first class, namely, the 

 Holsteins and the Ayrshires, the qualities particularly desirable in the 

 family cow, inasmuch as their milk is best for infants, and furnishes 

 a perfectly balanced ration alike for older children and adults. 



Again, important as are the chemical analysis of milk and urgent 

 as is the necessity of its being delivered fresh and uncontaminated, the 

 question of the vigorous health and temperament of the individual cow 

 is quite as vital. 



Let us then again consider the relative merits of the two classes 

 of dairy cows as heretofore indicated, in relation to their claim for 

 excellence in this indispensable particular. Mention will be made only 

 of the leading breed in each class in order to emphasize the illustra- 

 tion. 



It is a well-known fact that the Jerseys, as bred and cared for in 

 this country, have a highly irritable nervous temperament, and are 

 more difficult to feed, rear and manage than any other breed. 



The Holsteins, on the contrary, are a large, healthy breed of placid 

 temperament, great constitutional vigor, enormous digestive and pro- 

 ducing capacity, comparatively resistant to disease, and flourish to a 

 high degree in our trying climate. The same qualities which commend 

 the wet nurse in the performance of the function which the child's 

 natural mother is unable to perform, are those which should commend 

 to the community the cow which now, more than ever, sustains to the 

 infant population the relationship above indicated. 



Common knowledge independent of scientific observation sustains 

 the fact that a nurse with poor or delicate digestion, sensitivelv and 



