VI PREFACE. 



and to refer to standard works on the subject for the methods 

 except in the case of some of the simple tests. 



Dr. William H. Boynton, Assistant in Pathology and Bac- 

 teriology, New York State Veterinary College, has very gener- 

 ously permitted the use of the photographs appearing as figures 

 13 and 14, together with his description of them, in advance 

 of publication by himself. Professor G. C. Watson, General 

 Manager of the Tully Farms, Tully, N. Y., has kindly per- 

 mitted the use of photographs appearing as figures 3 and 4. 

 Dr. Francis H. Slack, Chairman of the Committee of the 

 American Public Health Association on Standard Methods of 

 Bacterial Milk Analysis, has rendered assistance by furnishing 

 a manuscript copy of the 1908 report of that Committee. 

 Specific acknowledgement as to sources of information has 

 been made largely throughout the text by means of the system 

 of references employed. 



It is not safe to indulge in the hope that important work 

 has not been overlooked, or that new facts may not require a 

 modification of attitude towards certain troublesome problems. 

 Therefore, assistance tending to improve the book will be 

 gratefully received. 



A. R. W. 



