INTRODUCTION 11 



ing steadily. Not only is important scientific work 

 being carried on l)y them in several directions, which 

 supplements the work of chemists and physicians, but 

 the necessity for milk control is constantly being pointed 

 out in meetings of veterinarians, in the International 

 Veterinary Congresses and in the Congresses for 

 Hygiene. A s])ecial journal is devoted to questions 

 l)ertaining to milk hygiene, in conjunction with meat 

 inspection, and sei)arate courses in milk hygiene are 

 given in many Veterinary Colleges. 



What follows is essentially the substance of lectures 

 given ))y the author in the Veterinary and Agricultural 

 College of Coi)enhagen. On some points in the prepara- 

 tion of the book, the lecture notes have lieen expanded ; 

 for example, in citing the instances of disease resulting 

 from milk i)Ossessing injui-ious properties. Since vet- 

 erinarians are fre(iuently consulted, ])y sanitary officers 

 and by dairymen, in regard to the adulteration of milk, 

 it is considered to be desirable to discuss rather thor- 

 oughly the composition of milk, the variations that occur 

 under different conditions, and the adulterations. It is 

 also considered to be appropriate to briefly treat upon 

 the use of milk as food for infants. 



Division ov Subject 



The subject matter of this book is divided into the 

 following parts : 



Milk and its composition. 



Injurious properties that milk may possess. 



Pasteurization and sterilization of milk. 



The use of milk for infants. 



In order to prevent the expansion of the book to 

 unnecessary proportions, the hygiene of other dairy 

 products as clieose and butter, and milk preparations 

 as condensed milk, milk powder, etc., is not discussed. 



