PART I. 



INTRODUCTION. 



Cow's milk has a peculiar place among our food 

 stuffs in that it is not only an important and indispens- 

 able part of the daily dietary of most people, but it is 

 being used more and more for the feeding of infants and, 

 indeed, is often almost the exclusive food for children 

 during the first years of life. It is, therefore, quite natu- 

 ral that at present when the science of hygiene is receiv- 

 ing so much attention especially in relation to the large 

 cities that there should be a demand for a reliable 

 supervision of market milk. It is true that the milk 

 trade in cities has been subject to a certain inspection, 

 but attention has been directed to only one side of the 

 question, to the possibility of adulteration, and to pro- 

 vide that fat is not removed and that there is no 

 alteration in the composition of the milk. From the 

 standpoint of hygiene this is merely of secondary im- 

 portance because it is in other ways that milk acquires 

 dangerous properties and may, indeed, become the 

 means of spreading virulent diseases. 



A properly organized milk control of the present 

 day can not, therefore, be restricted to determining 

 that milk offered for sale is unadulterated. On the 

 contrary, it must be its chief purpose to prevent milk 

 possessing injurious properties from coming into the 

 market and to prevent market milk from acquiring such 

 properties during the time that it is being handled and 

 stored. Since it is possible only by means of a thor- 

 ough, tedious examination to determine whether a given 



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