PREFACE TO AMERICAN EDITION. 



IT is doubtful whether any industry has changed more 

 during the past twenty years than has that of the produc- 

 tion of milk and its manufacture into butter and cheese. 

 Progress has been made in every direction. The present 

 generation has seen the shallow-setting system of cream- 

 raising superseded by the deep-setting systems, and these 

 again largely by hand or power separators. The wonderful 

 growth of the creamery movement, the invention of the 

 cream-separator and the butter-extractor, the introduction 

 of pure cultures in the manufacture of butter, have all 

 come to us during this time, as have also the various 

 methods of preserving milk for direct consumption; and 

 still more, underlying it all, an increased knowledge has 

 been gained and a fuller understanding of the nature and 

 properties of dairy products and the changes to which they 

 are subject. 



In this advance of the dairy industry the Scandinavian 

 countries have taken the most prominent part, Denmark 

 and Sweden having given the cream-separator to the 

 world the former country also contributing the method 

 of ripening cream by means of pure cultures, and the 

 latter the butter-extractor. Also Finland Scandinavian 

 by language, if not by government has contributed her 

 share to the advancement of dairying; and for a long time 



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