ill! A New Dairy Industry. 



depends. It was equally of importance to establish 

 a method to enable an examination of the keeping 

 qualities of milk which would manifest the spoilt 

 character of the milk even before this should be ex- 

 ternally visible. 



Commonly, the keeping quality of milk is judged 

 by the earlier or more protracted appearance of ciirdl- 

 ing. But milk is really spoilt before this occurs, as 

 the requisites for curdling are all present, so that it 

 needs only a slight warming to effect the separation. 

 The curdling of milk is, however, generally the con- 

 sequence of its acidity, and one would believe that 

 the reaction of the milk should furnish a measure for 

 the expected appearance of curdling. In the case of 

 raw milk this measure could, perhaps, be adopted, 

 and, in fact, experiment's have recently been made to 

 determine what must be the degree of acidity to make 

 milk curdle at warming ; this will be described later 

 on. The method, even if reliable results are to be 

 obtained by it, is one of complicated manipulations 

 suited only to laboratory work, and has for this reason 

 not received the attention and application it merits as 

 a means to examine milk brought to market, which 

 in itself is a most desirable investigation. When it, 

 however, comes to the manufacture of milk into food 

 for infants we can not operate with any such uncer- 

 tain factors, therefore the degree of acidity in the 

 milk to be used for this purpose must needs be ascer- 

 tained by the manufacturer ; there must be, absolutely, 



