160 MILK AND THE PUBLIC HEALTH CHAP. 



infants in tenement houses in New York upon cows' milk. 

 The investigation had three objects : 



(1) To make comparison of the results of infant feeding 

 in tenements in winter and summer. 



(2) To determine how far such results were affected by the 

 character of the milk used, especially its original bacterial con- 

 tent, its preparation, and whether it was fed after heating or raw. 



(3) To see to what extent results were modified by other 

 factors, such as the care the infants received and the surround- 

 ings in which they lived. 



The observations were extensive, 632 infants being care- 

 fully studied. In estimating the results obtained by the 

 different methods of feeding, the factors considered were the 

 gain or loss in weight and the amount of digestive disturbance, 

 particularly diarrhoea, which occurred. 



They divided the cases into four groups. The results 

 obtained were as follows :: 



Food and Results Winter. 



Food and Results Summer. 



