CONDENSED MILK 45 



(Z>) 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 b.etween 

 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 100. The 

 most common defect in condensed milks is deficiency in fat, 



