xx PRESERVATION OF MILK 393 



Condensed milk is undoubtedly used to a large extent for 

 infant feeding. In this connection the present regulations are 

 not precise enough as to the necessity for the unmistakable 

 differentiation of whole condensed and machine-skimmed con- 

 densed milk. The extensive use of the latter for infant feeding 

 is partly due to this reason and partly to ignorance on the 

 part of mothers. 



Coutts makes a number of valuable recommendations, of 

 which the following may be mentioned : 



1. Tins of condensed skimmed milk to be required to bear, 

 in a prominent and unobscured place, in letters of prescribed 

 size, the words, " Skimmed milk unfit for infants." 



2. Prohibition of the use of any preservative, except sugar, 

 in condensed milk. 



3. Control over trade statements liable to mislead the pur- 

 chaser as to the character, food value, or wholesomeness of the 

 product sold. 



4. Declaration of the content of milk fat and of added 

 substances foreign to milk. 



5. Some arrangement adopted for the systematic marking 

 of tins so as to indicate the manufacturer or person responsible. 

 If possible also the approximate date of canning should be 

 indicated. 



Dried Milk. Dried milk is now manufactured commer- 

 cially to a considerable extent. It is the powder obtained 

 either by passing milk rapidly between heated surfaces so 

 that it is deprived of its water, or by drying on a cylinder in 

 a partial vacuum. This dry powder, on being again mixed 

 with water, is converted into a fluid which looks like milk, 

 and which, on ordinary chemical analysis, shows the chemical 

 constituents of that substance. It is not, however, correct to 

 speak of such a fluid as milk, since it has been considerably 

 altered. The enzymes have been destroyed, the fat globules 

 have been physically altered, etc. It is a highly nutritive, 

 nearly sterile fluid, which may very possibly be in every way 

 as good a nutritive food as milk, but this has not been 

 proved. 



Dried milk is prepared by several processes, and the experi- 

 ments which have been carried out have shown that in all the 

 methods the temperature is sufficient to kill the non-resistant 



