GATHERED CREAM 169 



sample is used, and reduces the error in reading by one- 

 half. The small bore of the neck also lessens any error in 

 reading the test. 



In testing cream with this bottle, add 9 grams of 

 cream, 9 c.c. of water, 17.6 c.c. of sulphuric acid and 

 proceed with the test in the usual way, remembering that 

 the fat column gives the reading for an 18 gram sample. 



Preparing the Sample. Before weighing the cream on 

 the balance, care should be taken to thoroughly mix the 

 sample by pouring and repouring a few times. Should 

 the samples show any dried or churned cream, the sample 

 jars must be placed in water at a temperature of about 

 110° F. until the lumps of cream or butter have melted. 

 When this is done the sample for the test bottle must be 

 taken instantly after mixing, as the melted fat separates 

 very quickly. In general, warming the sample jars some- 

 what before sampling by placing them in warm water 

 will facilitate the mixing and sampling of the cream. 



Making and Reading Cream Tests. The different 

 steps in testing cream are essentially the same as in testing 

 milk. However, as already stated, the cream must be 

 weighed and tested in a special bottle. Furthermore, 

 special precautions must be used in reading the test. 



It is well known that reading the extremes of the fat 

 column gives too high a reading. This error is due to 

 the meniscus at the top of the fat column, the size of 

 which varies with the width of the neck. Farrington 

 and Woll recommend reading from the lowest extremity 

 of the fat column to the bottom of the upper meniscus. 

 This is the method commonly employed in reading tests. 

 Eckles and Wayman recommend removing the meniscus 

 by adding- a small quantity of amyl alcohol (colored red") 



