79 



The lactodensiraeter of Quevenne-Miiller bears the scale in a 

 brass tube, and is, therefore, preferred by those who find the work- 

 ing with glass instruments unprofitable. It bears two scales — the 

 one to the right to be used for whole milk, and the one to the left 

 for skim milk. 



The meaning of the fractions on the right — iV (29 — 26), -h 

 (26 — 23), etc. — is that the addition of water to whole milk is about 

 as corresponds to these fractions. On the left of the scale the 

 same is repeated, but the fractions appear in different places, 32.5 — 

 36.5, corresponding to normal unwatered skim milk. The fractions 

 on the left stand about 4 degrees lower on the scale, for the reason 

 that the specific gravity of milk gains 4 degrees by the process of 

 skimming. 



This double scale allows of a far more extended application 

 of the lactodensimeter than those which only give the specific 

 gravity. 



It would, perhaps, be even better to construct the densimeters 

 with a scale ranging from 1.020 to 1.040, and divide these 20 de- 

 grees over the space occupied by 28 degrees. The reading of 

 subdivisions of degrees would thereby be greatly facilitated. This, 

 from a practical point of view, is easily justified by the fact that, 

 in doubtful cases, at any rate, all milks showing specific gravities 

 outside of the limits 1.027 to 1.033, must be analyzed. 



It is, likewise, to be recommended to have the thermometer 

 inclosed into the areometer, as is done with those which are manu- 

 factured in Germany. 



Each lactodensimeter must be carefully examined for its accu- 

 racy, by comparing the results obtained with it with those obtained 

 by means of a specific gravity bottle, and only instruments giving 

 correct readings for at least three decimals should be employed. 



Determination of the specific gravity : The apparatus neces- 

 sary for this are : 



1. A well adjusted and examined lactodensimeter of Quevenne, 

 with or without inclosed thermometer. 



2. An accurate Celsius thermometer. 



3. Glass cylinders sufficiently high and wide to admit of the 

 introduction and use of the lactodensimeters. 



