1890.] PUBLIC DOCUMENT — No. 4. 143 



testing tubes, because I desired to have them correspond 

 with the depth of the pails in which I set the mass of 

 my milk. 



How used. 



The manner of using these cans, and determining results, 

 is very simple. Each can is filled with the milk of an indi- 

 vidual cow, immediately after being drawn, and placed in 

 tanks of water at a temperature of sixty-three degrees. All 

 are submitted to precisely the same conditions, and a record 

 taken at six, twelve, twenty-four and thirty-six hours from 

 the time of milking. In this manner I learned many inter- 

 esting practical facts. Among these were : — 



1. That the milk of each individual cow has its own pecul- 

 iar time for sending up its cream. 



2. That this time is dependent upon the characteristics of 

 the milk, and its butter globule. 



3. That, knowing these characteristics of the different 

 samples, we may readily determine their comparative value 

 for butter-making purposes. 



Tell me the time required for a given sample of milk 

 to send up its cream through a depth of twelve inches, at a 

 temperature of sixty-three to sixty-five degrees, and I will 

 tell you its quality for butter-making purposes. Tell me 

 also with regard to the annual milk })roduction of the cow 

 furnishing such sample, and I will tell you her standing as a 

 butter producer. 



The first tests of my herd gave some surprising results. 

 While the milk of one cow parted with its entire cream 

 (thirty per cent) in three hours, that of another, standing by 

 its side, continued to rise for thirty-six hours, while I had 

 reason to believe that much of it never came to the surface. 



These novel and unexpected results of course excited my 

 curiosity, and led me to study the phenomena presented in 

 the manipulation of milk. Further investigation revealed 

 the causes of this wide difierence in results. They were 

 easily traced to the difierence in the peculiar qualities of the 

 two samples. 



The first was found to have a large uniform butter glob- 

 ule, to contain comparatively little caseine and other milk 

 solids. The milk when skimmed had a thin, blue, watery 



