352 Milk and Its Products 
To Determine Lactic Actin, Usine 17.6 c. c. or MILK on CREAM 
Instead of determining lactic acid as described above, it is often 
more convenient to make the tablet solution of such a strength that 
1c. c. of the solution will neutralize .01 per cent of lactic acid in the 
amount of milk or cream taken. Since a 17.6 c. c. pipette is always 
found where there is a Babcock testing outfit, 17.6 c. c. is a very con- 
venient assay, as it does not necessitate procuring an additional 
pipette. If 5 Farrington tablets are dissolved in 97 c. v. of water the 
solution will be of such a strength that each ec. ec. of solution 
will neutralize .01 per cent of lactic acid in 17.6 c. c. of milk, and the 
total number of c. cv. used will indicate the amount of lactic acid present 
in hundredths of one per cent; e. g.: 
5 tablets are dissolved in 97 c. c. water, and 35 c. c. of the solu- 
tion are required to neutralize the lactic acid in 17.6 ¢. c. of cream; 
the percentage of lactic acid present is therefore .35 per cent. 
To Sevect Mitk For PasTEURIZATION 
Dissolve any convenient number of Farrington alkaline tablets in 
an equal number of ounces of water. Provide any convenient small 
measure, and to one measure of milk add two measures of the pre- 
pared tablet solution. If the milk remains uncolored, it contains 
more than .2 of 1 per cent of acid, and is too sour to be safely 
used. If it is colored pink, it contains less than .2 of 1 per cent of 
acid, and may safely be used for pasteurizing or sterilizing. Or, the 
tablet solution will be of very nearly the same strength, and may be 
used in the same way, if 3 tablets are dissolved in 90 c. c. of water. 
To PREPARE VISCOGEN FOR RESTORING THE CONSISTENCY 
.OF PASTEURIZED CREAM 
Two and one-half parts by weight of a good quality of granulated 
sugar are dissolved in five parts of water, and one part of quick lime 
gradually slaked in three parts of water. The resulting milk of lime 
is strained and added to the sugar solution. The mixture should be 
agitated at frequent intervals, and after two or three hours allowed 
to settle until the clear liquid can be decanted off. This clear liquid 
(viscogen) is the part used and should be kept in well-stoppered bottles, 
as it loses strength and becomes dark-colored when exposed to the air. 
The darkening in color, however, does not impair its usefulness. 
