CONDENSED MILK 45 



(6) The albumin is determined by means of magnesium 

 sulfate. If less than 0.35 per cent, is found, sterilized milk 

 may be considered to be present. 



(c) The milk-sugar is determined by the polarimeter, and 

 also gravimetrically, in duplicate. If the difference between 

 the two estimations be more than 0.2 per cent., it will be cor- 

 roborative evidence of the presence of sterilized milk. It is 

 doubtful whether a proportion of sterilized milk much below 

 30 per cent, can be detected. 



The following figures, by Stewart, show the percentage of 

 soluble albumin found in milk raised to various temperatures: 



CONDENSED MILK 

 The form of condensed milk called "evaporated cream" con- 

 sists merely of whole milk concentrated to about two-fifths 

 of its bulk, but most condensed milks contain a considerable 

 amount of cane-sugar. These samples represent, usually, 

 whole milk concentrated to about one-third or two-sevenths 

 of its original volume. A small amount of invert-sugar may 

 be present. Portions of the lactose may crystallize from con- 

 densed milk, and when solutions are prepared for analysis, 

 abnormal polarimetric reading will result unless the liquid 

 stands for some hours or is heated for a short time to ioo°. The 

 most common defect in condensed milks is deficiency in fat. 



