384 



THE CHEMICAL CONTROL OF THE DAIRY. 



The normal ratio of ash to solids not fat and their excessive 

 amount point to the milk having been concentrated. 



The milk had also been deprived of a portion of its cream. 

 Example b. The analytical figures were : 



Total solids, 



Fat, . 



Milk-sugar (polarised), 



(gravimetric 



Ash, . 

 Solids not fat, 



16-23 per cent. 



2-05 

 15-83 



3-12 



0-59 

 14-18 



The extreme difference between the polarimetric and gravi- 

 metric figures for milk-sugar points to the presence of added 

 sugar, probably cane sugar in aqueous solution. This sample 

 may possibly have been a diluted condensed milk. 



Example c. The analytical figures were : 



Specific gravity, . 



Total solids, 



Fat, . 



Milk-sugar, 



Protein, 



Ash, . 



Solids not fat, 



1-0293 



10-21 percent. 

 2-43 

 5-12 

 2-25 

 0-41 

 7-78 



The low ash and protein point to the presence of 35 per cent, 

 of added water ; there has also been an addition of milk-sugar, 

 probably to mask the addition of water. 



PROBLEM IV. To determine reason for milk being called 

 " poor." 



It is evident that either watering or abstraction of cream 

 would cause the milk to appear poor ; it is unnecessary to give 

 further examples of this kind. 



Example a. The analytical figures were : 



Specific gravity, 

 Total solids, 

 Fat, . 

 Albumin, 

 -Ash, . 

 Solids not fat, 

 Cream in six hours, 



1-0326 



13-45 per cent. 

 4-30 

 0-10 

 0-75 

 9-15 

 1-3 



This milk was normal in composition and contained a good 

 .percentage of cream. The low albumin and small amount of 

 cream thrown up in six hours showed that it had been boiled. 

 It was probably the slow rate of rising of cream, due to the 

 milk having been raised to a high temperature, that caused 

 a suspicion of " poorness." 



