38 DAIRY CHEMISTRY 



ing corrections for temperature, the following general 

 rule can be applied : When the temperature is 

 greater than 60° F., add .1 of a lactometer degree for 

 each degree of temperature, and when less than 60° F., 

 subtract .1 for each lactometer degree. This gen- 

 eral rule will apply only for a variation of 15 degrees 

 either above op below the temperature of 60°. In 

 case more accurate corrections for variation in tem- 

 perature are desired, these will be found in the tables 

 in the appendix. 



45. Other Lactometers. — The New York Board of 

 Health lactometer is graduated into 120°. The 100 

 mark represents milk with a specific gravity of 

 1.029; milk with a lower gravity shows a reading 

 of less than 100 on the lactometer scale, the per- 

 centage being somewhat proportional to the amount 

 of water added, a reading of 75 indicating that the 

 milk is 75 per cent pure, while a reading of more 

 than 100 indicates that the milk is above legal 

 standard as to fat content. These readings are, in 

 general, proportional to the character of the milk 

 and show whether extensive adulterations, as skim- 

 ming or watering, have been practiced. But, con- 

 sidered alone, the lactometer results obtained by 

 either the Quevenne or the New York Board of 

 Health lactometer are liable to error, not on account 

 of any imperfection in the principle or the instru- 

 ment, but because of the complexity of the composi- 

 tion of milk. When, for purposes of comparison, it 

 is desired to change the readings of the New York 



