FROM THE PRACTICAL VIEWPOINT 



taken from the milk which was last discharged 

 from the holder. This milk had been in the holder 

 for exactly sixty minutes. Upon standing, this 

 milk showed 9 per cent, of cream and 3.7 per cent, 

 butter fat. 



These results indicated that milk could be heated 

 to 145 and held for thirty minutes without any 

 injurious effect upon the cream line being pro- 

 duced, but that if the milk was held for an hour, 

 the cream line was considerably affected. 



EIGHTH TEST. A further test was made at a 

 pasteurizing plant in which the milk was heated 

 by means of the heater shown in Fig. 7, and held 

 in the holder illustrated in Fig. 27- In this appa- 

 ratus the milk is forced through a series of pipes 

 which are themselves enclosed in a larger pipe 

 through which hot water is forced. The holding 

 apparatus consists of a series of large tubes 

 through which the milk is allowed to flow. It re- 

 quires about thirty-five minutes for the milk to be 

 discharged through the holding tubes. 



A sample was taken from the raw milk, before 

 clarifying. This was found to contain !5 l / 2 per 

 cent, of cream and 3.5 per cent, butter fat. A sec- 

 ond sample was taken from milk which had been 

 225 



