2 BULLETIN 524,. U. S. DEPARTMENT OF AGRICULTURE. 
prevent excessive souring, to " lime " or " neutralize " cream of high 
acid content, before pasteurization, in order to reduce its acidity and 
improve the salable quality of the butter made from it. Some 
creameries use sodium carbonate for this purpose instead of lime. 
The work reported in this bulletin was undertaken for the purpose 
of developing and perfecting a method for detecting with certainty 
the addition of lime to cream before its manufacture into butter. It 
is believed that no such method has heretofore been published. The 
detection of alkali salts when used to neutralize dairy products has 
not been considered in this publication but has been left for future 
work. Nor has any consideration been given to the question of pos- 
sible detriment to health, or to the legal, economic, and ethical phases 
of the process discussed in this bulletin. 
Milk and products derived from milk contain calcium phosphate 
as one of the principal constituents of the ash. Leach 1 states that 
the percentage of calcium oxid in the ash of a typical milk is 20. 
T>lyth 2 gives figures ranging between 17.31 and 27.55 with a mean 
of 22. Tibbies 3 quotes an analysis by Schrodt wherein the calcium 
oxid is 21.45 per cent of the ash. Konig 4 gives a figure of 22.42 per 
cent. Kostler 5 reports values for the percentages of calcium oxid 
in the ash of milk, cream, buttermilk, and butter. His maximum 
and minimum figures are given in Table 1. 
Table 1. — Percentages of calcium oxid in the ash of dairy products, as 
calculated by Kostler. 
Number 
of 
analyses. 
Calcium oxid in ash. 
Substance. 
Maxi- 
mum. 
Mini- 
mum. 
Milk 
10 
1 
1 
19 
11 
Per cent. 
24.63 
24.48 
23. 09 
24.54 
22.83 
Per cent. 
22.24 
Buttermilk 
21.22 
20.07 
Shaffer and von Fellenberg 6 found values between 18.3 and 20.2 
per cent for butter. 
1 Leach, Albert E., Food Inspection and Analysis, 3d ed., p. 128, New York, 1913. 
2 Blyth, A. W. and M. W., Foods : Their Composition and Analysis, p. 201, London, 
1909. 
3 Tibbies, William, Foods, Their Origin, Composition, and Manufacture, p. 245, London, 
1912. 
4 Konig, J., Chemie der Menschlichen Nahrungs- und Genussmittel, 4th ed., v. 2, p. 603, 
Berlin, 1904. 
6 Kostler, G. Zur Charakterisierung unserer schweizerischen Butterarten. In Landw. 
Jahrb. der Schweiz, 25 (1911), 249-276. 
6 Shaffer, F., and v.on Fellenberg, Th. Zur Unterscheidung der Butterarten. In Mitt. 
Lebensm. Hyg., 2 (1911), 220. 
