TRANSLATOR'S PREFACE 



certain, important chapters from animal husbandry, 

 dairy husbandry and dairy industry. 



Until quite recently, milk inspection in the United 

 States has been carried on by untrained men who have 

 had little, if any, knowledge of the sources or nature of 

 the contaminations of milk or of the means by which 

 they must be avoided ; their whole technical equipment 

 has consisted in a few rule-of-thumb tests to detect 

 gross adulterations. A large number of milk inspection 

 services are still organized on this basis. In several 

 cities, however, attention has been paid to microscopic 

 and bacteriologic examinations of milk, and it has been 

 shown that a very large proportion of the supply fails to 

 meet even a moderate standard for cleanliness, thus re- 

 vealing the need for measures at the seat of production 

 and during transit to prevent injurious contaminations. 



It is becoming increasingly manifest to sanitarians 

 that more must be done to protect consumers from the 

 unwholesome conditions and the diseases propagated 

 and transmitted by milk and the broader men in dairy 

 industry realize that milk must be made safe and be pro- 

 tected if it is to find and retain its proper place in the 

 dietary of the people. 



This makes a demand for a discussion of milk 

 hygiene from the standpoint of the sanitary supervision 

 of market milk from the side of the man who is to do 

 the practical work of protecting the milk supply and it 

 is this demand that Professor Jensen's book is planned 

 to meet. 



LEONARD PEARSON. 



