MILK INSPECTION i 9 jr 



rminute and the percentage of fat is read off in the neck of the bottle 

 lay measuring with calipers from the lower to the upper border of 

 the fat in the neck. The reading must be done before the contents 

 or the bottle cool off. The addition of the hot water may be 

 -■accomplished without removing the bottles from the machine (see. 

 Frontispiece). 



Estimation of Solids in Milk by Quevenne's Lactometer 



Since most cities require that market milk shall contain a 

 standard percentage of milk solids, it is of advantage that the 

 farmer be able to determine this matter for himself. 



Quevenne's lactometer (Fig. 59) is an instrument by which 

 the solids can be roughly estimated. It consists of a glass bulb 

 -weighted with mercury and terminating in a stem like a thermom- 



Kg- 59- 



I fa a fc! b? h to ^ j a a g fa fci g fci big 



Quevenne's Lactodensimeter or Lactometer. 



•■eter, and marked by lines on the stem from 15 to 40. It should 

 also carry a thermometer. 



The principle upon which the lactometer is based depends upon 

 the . fact that, when it is placed in milk, in floating it displaces a 

 bulk of milk equal in weight to the weight of the lactometer. The 

 milk must be thoroughly mixed — but free from bubbles of air — 

 ■and the reading is taken at the actual level of the milk; not at the 

 point of the stem to which it is drawn by capillary attraction. 



The lactometer is then used to determine the weight of milk 

 (or in other words, the specific gravity) as compared with the 

 weight of an equal bulk of water when both are at the same 

 temperature. 



If 1,000 is taken as the weight of a certain quantity of water, 

 the weight of the same quantity of milk, at the same temperature, 



