96 Testing Milk and Its Products. 



meter, the milk is always warmed or cooled so that its 

 temperature does not vary ten degrees either way from 

 60 F. 



110. The temperature correction table for whole milk, 

 given in the Appendix shows that if, e. g., the specific 

 gravity of a sample of milk taken at 68 F. was found 

 to be 1.034, its specific gravity would be 1.0352 if the 

 milk was cooled down to 60. If the specific gravity 

 given was found at a temperature of 51, the corrected 

 specific gravity of the milk would be 1.0329. 



In practical work in factories or at the farm, sufficiently 

 accurate temperature corrections may generally be made 

 by adding . 1 to the lactometer reading for each degree 

 above 60 F., and by subtracting .1 for each degree below 

 60; e. g., if the reading at 64 is 29.5, it will be about 

 29.5 + .4=29.9 at 60 F.; and 34.0 at 52 F. will be 

 about 34.0 -.8 =33. 2 at 60 F. The table in the Appen- 

 dix gives 33.0 as the corrected figure in both cases. 



The scale of the thermometer in the lactometer should 

 be placed above the lactometer scale so that the tempera- 

 ture may be read without taking the lactometer out of 

 the milk; this will give more correct results, will facil- 

 itate the reading and save time. 



111. N. Y. Board of Health lactometer. In the East, and 

 among city milk inspectors generally, the so-called New 

 York Board of Health lactometer is often used. This 

 does not give the specific gravity of the milk directly, 

 as is the case with the Quevenne lactometer, but the scale 

 is divided into 120 equal parts, known as Board of Health 

 degrees, the mark 100 being placed at the point to which 

 the lactometer sinks when lowered into milk of a. specific 



