230 Milk Inspection. 



milk is below 1 . 028, that of the serum below 1 . 026 and the content 

 of fat-free solids falls considerably below 8%. 



2. Cream has been removed from the milk when in the pres- 

 ence of an increased specific gravity of the milk and normal specific 

 gravity of the serum or normal content of fat-free solids, the per- 

 centage of fat content of the milk solids falls considerably below 

 20% ; that is, the specific gravity of the latter is increased consider- 

 ably above 1.4. 



3. Adulteration with water together with removal of some 

 of the cream may be suspected when with a normal specific gravity 

 of the milk, that of the serum falls below 1.026, and with a dimin- 

 ished amount of all the ingredients of the milk the fat content of 

 the solids falls considerably below 20% ; that is, the specific gravity 

 of the latter is increased considerably over 1.4. The percentage 

 of fat contents of the solids is obtained from the following formula : 



f X 100. 



At the same time it must be remembered that no definite 

 figures of limitation should exist and that only comparative figures 

 are convincing. The sample for comparative tests may be ob- 

 tained by informing the manager of the dairy or the responsible 

 producer that the milk is suspected of being watered, and he is 

 directed to devote special attention to the milk production and its 

 subsequent handling. If following this procedure the milk becomes 

 notably changed the test may be considered as comparative, pro- 

 vided that it is not preferred to undertake immediately an official 

 comparative test. This must be done as quickly as possible, and 

 not later than the third day after the suspicion has been estab- 

 lished. According to Herz the following formulas apply in the 

 calculation of adulterations : 



w = the added water contained in 100 parts of milk. 



v == the added water to 100 parts of milk. 



p = the fat removed from 100 parts of milk. 



F! = the fat-free solids of the stable sample. 



r 2 = the fat-free solids of the suspected market sample. 



fi = fat contents of the stable sample. 



f 2 = fat contents of the suspected market sample. 



M = 100 w, the amount of original undiluted milk contained 

 in 100 parts of watered milk. 



100 X (r, r,) 



w 



100 X (r, r 2 ) 



f.X (f,- 



P 



