The Lactometer and its Application. 99 



of the milk is thereby increased; with the quantity usu- 

 ally added ( gram to a pint of milk) the increase amounts 

 to about 1 lactometer degree, and this correction of lacto- 

 meter readings should be made with milk samples pre- 

 served in this manner. To avoid this error, Dr. Eichloff 1 

 recommends using a solution of bi-chrornate in water 

 (43 grams to 1 liter), the specific gravity of which is 

 1.032, or similar to that of average milk; 5 cc. of this so- 

 lution is required for a pint of milk. No correction is 

 necessary for the dilution with this small amount of liquid 

 preservative. 



115. Cleaning of lactometer. The lactometer should be 

 cleaned directly after using, by rinsing with cold water; 

 it is then wiped dry with a clean cloth and placed in the 

 case. 



CALCULATION OF MILK SOLIDS. 



116. A number of chemists have prepared formulas for 

 the calculation of milk solids when the fat content and 

 the specific gravity (lactometer reading) of the milk are 

 known. By careful work with milk tester and lacto- 

 meter it is possible by means of these formulas to deter- 

 mine the composition of samples of milk with consider- 

 able accuracy outside of, as well as in chemical laborator- 

 ies. As the complete formulas given by various chemists 

 (Behrend and Morgen, Clausnitzer and Mayer, Fleisch- 

 mann, Hehner and Kichmond, Eichmond, Babcock) 2 are 

 very involved, and require rather lengthy calculations, 

 tables facilitating the figuring have been prepared. The 

 formulas in use at the present time, in this country and 



1 Technik der Milchpriifung, p. 98. 



2 Agricultural Science, vol. Ill, p. 139. 



