ON MILK AND MILK-TESTING 93 



silver nitrate solution. The strength of this silver 

 nitrate solution is such that i c. c. of it represents 

 one-tenth of i per cent of salt. 



3. The Fitch salt test. A representative 3.5- 

 gram sample of butter is placed in a 300 c. c. glass 

 flask and 180 c. c. of boiling water added. The 

 flask is then corked and thoroughly shaken, care 

 being taken to remove the cork often tt) relieve the 

 pressure. The mixture is then allowed to cool and 

 after the fat has collected on the top and solidified 

 17.6 c. c. of the clear solution beneath the fat is 

 placed in a white cup. Then 17.6 c. c. of potassium 

 chromate indicator is added and the solution 

 titrated with a standard silver nitrate solution meas- 

 ured from a graduated cylinder till the solution be- 

 comes a permanent reddish color. The number 

 c. c. silver nitrate used divided by io=per cent salt. 



How is the moisture content of butter determined? 



1. By chemical analysis. 



2. By practical moisture tests. 



What are the names of the more commonly used 

 moisture tests? 



1. Cornell test. 



2. Mitchell-Walker. 



3. Irish. 



4. Gray's. 



5. Farrington. 



How should a representative sample of butter be 

 secured and prepared for making a moisture, 

 salt, or fat test? 

 From the mass of butter to be tested take several 



