. Dairy chemistry; a practical handbook for dairy chemists and others having control of dairies. Agricultural chemistry; Milk. 134 ANALYSIS OF MILK. is titrated with tliis, and the number of used divided by 10 will give the acidity in terms of lactic acid; this practice is, however, to be deprecated, as freshly-drawn milk has a very distinct acidity, though lactic acid is in all probability absent. The acidity of milk to phenolphthalein is due partly to the mono- and di-basic phosphates, and partly to the dissolved carbonic acid. Soxhlet and Henkel have proposed the use of N normal soda s
. Dairy chemistry; a practical handbook for dairy chemists and others having control of dairies. Agricultural chemistry; Milk. 134 ANALYSIS OF MILK. is titrated with tliis, and the number of used divided by 10 will give the acidity in terms of lactic acid; this practice is, however, to be deprecated, as freshly-drawn milk has a very distinct acidity, though lactic acid is in all probability absent. The acidity of milk to phenolphthalein is due partly to the mono- and di-basic phosphates, and partly to the dissolved carbonic acid. Soxhlet and Henkel have proposed the use of N normal soda solution, and use a special apparatus (Fig. ] 3); they express the acidity as degrees ; 1 Soxhlet-Henkel degree = the number. Fig. 12.—M'Creath Acidimeter. .N of of ^ alkali used per 100 of milk ; it is to be regretted that this " degree " has been introduced, as it is 2-5 times larger than the ordinary degree, and has caused confusion. Instead of using phenolphthalein, delicate neutral litmus paper may be employed; milk is practically neutral to this. The acidity can be titrated with fair accuracy, though the end point of the titration is not well marked. There is more justifi- cation for calculating the acidity to litmus as lactic acid, as both. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Richmond, Henry Droop. London, C. Griffin & Company, Limited
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectagriculturalchemistr
