PREFACE TO SECOND EDITION 



The writer and publishers feel gratified that a second 

 edition of this work is called for within a little over a year 

 from its first appearance. 



Such rapid advances have occurred in the knowledge 

 of subjects herein treated that it has been found necessary 

 to very materially add to and alter the former text — so 

 much so, that many chapters of the present volume have 

 been re-written and very considerably expanded. 



The attempt has been made in this revision to so 

 ■extend the scope of the original work as to supply to 

 veterinary, agricultural and dairy students, and to health 

 officers, a text-book on practical milk inspection and dairy 

 hygiene, which are becoming of such importance to the 

 public health. 



Moreover, the author has had the advantage of the 

 collaboration of Dr. H. W. Hill, whose work in milk 

 bacteriology is well known. 



The writer also desires to acknowledge his grateful 

 indebtedness to Professor Conn for his generosity in per- 

 mitting the use of the laboratory experiments in dairy 

 bacteriology. 



Both of these additions should prove of great benefit 

 .to students of milk bacteriology. 



Kenelm Winsi.ow. 



