The Lactometer and Its Application. 109 



tained are 1.022, 1.029, and 1.036, for 3, 4, and 5 pei 

 cent, solutions, respectively. 



Calculation of Milk Solids. 



119. 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 

 lactometer it is possible by means of these formulas to 

 determine the composition of samples of milk with con- 

 siderable accuracy, both cutside of and in chemical lab- 

 oratories. As the complete formulas given by various 

 chemists (Behrend and Morgen, Clausnitzer and I\Iayer, 

 Pleischmann, Hehner and Richmond, Richmond, Bab- 

 cock)^ 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 abroad, are those proposed by Fleisch- 

 mann, Hehner and Richmond, or Babcock. Babcock's 

 Formula is the one generally taught in American dairy 

 schools and is therefore given here ; it forms the foun- 

 datiim for Tabic VI in the .\ppendix for the calculation 

 of solids not fat. 



By the use of these tables the percents of solids not 

 fat may be found, corresponding to lactometer read- 

 ings from 26 to 36, and to fat contents from to 6 

 per cent. The formula, as amended in 1895,- is as fol- 

 lows, S being the specific gravity and / the per cent, of 

 fat in the milk. 



Solids not fat=(^,„g,;;^^,^-l)(100-f)2.5 



» Agricultural Science, vol. Ill, p. I3y. 



'Wisconsin experiment station, twelfth report, page 120. 



