160 THE MODERN MILK PROBLEM 



mand, although, to be sure, these effects are subject 

 to modification by conditions of present-day milk in- 

 dustry which we have considered elsewhere. 



THE ROLE OF THE LABORATORY 



In gauging the quality of milk the scientific method 

 is to rely upon the indication of the laboratory as op- 

 posed to the less accurate indications of inspection. 

 Reasons for this have already been set forth in Chapter 

 III, in the discussion of the score-card method of 

 dairy inspection. By means of inspection such matters 

 as health of cows and methods of operating milk plants 

 may be looked after, but, as regards operations in the 

 dairy, it is seldom possible to observe them. Inspec- 

 tion is therefore chiefly a means of giving advice or 

 instruction to the dairyman. But, by means of the 

 laboratory, samples of a milk may be taken at any 

 stage of its history and subjected to specific tests. 

 These tests can disclose not only its general bacteri- 

 ological and chemical character but also, perhaps, the 

 quantity of dirt which has contaminated it, and can 

 even detect abnormal udder conditions in the milch 

 cow when physical examination of the animal would 

 not do so. 



Laboratory methods are steadily being developed in 

 scope and exactitude. They must rightly be regarded 

 not as a mere adjunct of inspection but as a first means 

 of indicating where inspection or rather instruc- 

 tion is needed. 



A recent paper by Dr. Charles E. North, arguing 

 cogently for proper correlation of laboratory and in- 

 spection work, and putting the laboratory test before 



