54 MILK 



of distinctly different tint from the milk below it. 

 Deception has of late been extensively practised 

 by a treatment of milk which breaks up the fat 

 globules and increases the volume of cream 

 formed, so that a slightly skimmed milk will yield 

 a fair volume of cream. Determination of fat by 

 the usual methods will show the fraud. See 

 page 65. 



It has been found that many of the bottles 

 used for distribution of milk are not of the capac- 

 ity designated on them, but this is a matter of 

 police regulation. 



Perservatives. — These are largely used, es- 

 pecially in the warmer season, as a substitute for 

 refrigeration. Many of them are sold under 

 proprietary names which give no indication of 

 their composition. Preparations of boric acid 

 and borax were at one time the most frequent 

 in use, but at present formalin, a 40% solution 

 of formaldehyd, has come into favor. Sodium 

 benzoate is now in common use as a preservative 

 of cider, fruit- jellies, and similar articles, and 

 may, therefore, be found in milk. Salicylic 

 acid is not so much employed. Sodium car- 

 bonate is occasionally used to prevent coagula- 

 tion due to slight souring. Fluorids and abrastol 

 may be used. A mixture of boric acid and borax 

 is more efficient than either alone. The quantity 

 generally used is equivalent to about 0.5 gram of 



