30 
LABORATORY MANUAL 
EXERCISE NO. 22 
Object: To demonstrate the fallacy of testing cream by volume. 
Procedure: “Several factors tend to render inaccurate the measuring of 
cream for the Babcock test, and correct results can therefore 
only be obtained by weighing the cream.” (F. & W. % 86). 
A. Test a sample in duplicate as in exercise 21. 
B. Measure out a 17.6 cc. sample of the above cream into each of 
two cream test bottles and complete the test in the usual man¬ 
ner. 
Note: In case the 9 gram sample is the legal sample, weigh 
out 9 grams of cream under A above, add about 9 cc. ol water 
and mix. Then add 17.5 cc. of sulfuric acid, mix, and test as in 
Exercise 21. 
Observations: 
Sample 
% fat 
Color 
Condition 
1 
a 
b 
2 
a 
b 
Conclusion: 
Questions: (1) Give three reasons why the cream samples should be 
weighed rather than measured with a pipette. 
(2) Give a table of figures to show how the richness of cream influ¬ 
ences its weight. 
(3) Explain the use of, and describe the construction of the Wis¬ 
consin hydrostatic cream balance. 
(4) Give a formula for calculating the test of a sample of cream 
if less than 18 grams are used in an 18 gram test bottle. 
References: F. & W. H 85-89 inclusive; Van S. pp 73-92; Jud. pp 75-85; 
St. pp 119-128. 
