APPENDIX. 



I. THE LACTOMETER. 



1. The lactometer is a hydrometer which indicates specific gravi- 

 ties between 1.000, the gravity of water, and 1.0348. 



2. It is used to determine the specific gravity 

 of the milk. 



3. As the specific gravity varies with the 

 temperature, the observations are made at a 

 standard temperature of 60 Fahr. 



4. The specific gravity of the average milk 

 at a milking of a healthy cow, properly fed and 

 in a normal condition, varies from 1.029 to 

 1.0348. The former number being the lowest 

 or minimum gravity, 100 is placed at this 

 point on the lactometer ; is placed at 1.000, 

 the gravity of water ; the intervening space is 

 divided into 100, and the graduations are con- 

 tinued to 120, which corresponds to the speci- 

 fic gravity 1.0348. 



5. To apply the lactometer, the temperature 

 of the milk is first noted with the aid of the 

 thermometer ; the lactometer is then carefully 

 inserted, taking pains to avoid wetting the 

 portion of the stem above the milk, and to free 

 the surface of the milk from foam. The degree 

 to which the instrument sinks is then noted. 

 Bearing in mind the effect of temperature on 

 the gravity, the inspector now decides whether 

 the gravity will probably be below 100 at 60 

 Fahr. If he thinks it will, he carefully cools or 

 warms a sample of the milk, as the case may 

 require, to 60 Fahr., and again inserts the lac- 

 tometer. If it stands below 100, the gravity 



is below that of any genuine milk. He carefully notices the con- 

 sistence to determine whether he has before him a sample of thin 

 watered milk or a sample of thick cream. The black background of 



