128 MANUAL OF MILK PRODUCTS 



meniscus in the reading. Glymol should be used in the read- 

 ing of the cream test only; the milk test should be read 

 without the use of glymol. If glymol were used in the read- 

 ing of the milk test, the results would be too low. Experi- 

 mental results have indicated that in the milk test the meniscus 

 compensates for the loss of residual fat. It therefore must be 

 included in the reading. 



Glymol may be purchased in drug stores. Ask for white 

 mineral oil. 



Coloring glymol 



Some operators prefer the use of colored glymol. Glymol is 

 best colored with alkanet root, which gives it a bright cherry 

 color. Use one ounce of crushed alkanet root to one quart of 

 glymol. Wrap the alkanet root in a small piece of cheesecloth 

 and drop it into the vessel containing the glymol. The alkanet 

 root may be removed from the glymol after twenty-four to 

 forty-eight hours. 



Alkanet root is sold by druggists at about twenty-five cents 

 a pound. 



Abnormal appearance of the fat column 



If the test has been made properly and in accordance with 

 above instructions, the fat column is clear and has a golden 

 yellow color. 



Milky curd in and immediately below the fat column shows 

 that not enough or too weak acid was used. A charred and 

 dark curdy fat column indicates the use of too much or too 

 strong acid. Abnormal tests should be rejected, as the reading 

 usually is indistinct and misleading. 1 



1 For directions for avoiding the presence of foam on the surface 

 of the fat column, see "Abnormal Appearance of the Fat Column" on 

 page 118. 



