PREFACE 
In this book an effort has been made to present 
systematically, in concise form, the facts and principles 
which are of importance in the practice of milk hygiene 
and to describe how they may be applied in the inspec- 
tion of dairy farms and in the examination of milk. The 
material has been obtained from various sources. Jen- 
sen’s “ Milk Hygiene,” Savage’s “‘ Milk and the Public 
Health,” Conn’s “ Practical Dairy Bacteriology,” Swith- 
inbank and Newman’s “ Bacteriology of Milk,” King’s 
“ Ventilation,” Van Slyke’s “‘ Modern Methods of Test- 
ing Milk and Milk Products,” Grimmer’s “‘ Chemie und 
Physiologie der Milch,” Rievel’s “‘ Milchkunde,” Weig- 
mann’s “ Mykologie der Milch,” Ernst’s “ Milchhygiene 
fiir Tierdrzte,’ Sommerfeld’s ‘‘ Handbuch der Milch- 
kunde,” and Barthel’s “ Methoden zur Untersuchung 
von Milch und Molkereiprodukten” have been freely 
drawn upon, while articles by numerous research workers 
which have appeared in the various journals and official 
reports have furnished many important facts. To all of 
these authors and investigators due acknowledgment is 
made. 
The book is intended primarily as a text for students 
taking a course in milk hygiene, but it is the hope of the 
author that it will also prove of service to dairy inspec- 
tors, milk examiners, public health officials, dairymen, 
milk distributers, and others interested in the production 
of wholesome milk. 
Louis A. Kien 
PHILADELPHIA, Pa. 
SEPTEMBER 15, 1917. 
