400 



THE KEEPING OF MILK. 



Another experiment gave almost identical figures. 



It is probable from these experiments that milk exposed to a 

 temperature of 10 C. always will yield a liquid portion having 

 the composition given above. The figures also show that milk 

 cannot be frozen into blocks, from which pieces can be cut off and 

 melted c for use, without modifying the composition to a serious 

 extent. 



The author has had the opportunity of examining three samples 

 of milk which had been frozen for transport and remelted (Table 

 CXXXVIIL). 



The samples were taken under such conditions as would repre- 

 sent the retailing of the milk. 



TABLE CXXXVIIL COMPOSITION OF FROZEN MILK. 



No. I. has the composition of concentrated milk, No. II. of a 

 watered milk, and No. III. of a slightly skimmed milk. 



Attempts have been made to introduce frozen, or partially 

 frozen, milk into the English market from Holland and other 

 foreign countries. The above figures show what may be some- 

 times the composition of milk as retailed, unless extreme care be 

 taken in melting the imported product. 



Condensed Milk. 



For convenience of transport, milk is deprived of the bulk of 

 its water by evaporation under diminished pressure in a vacuum 

 apparatus fitted with a condenser, or by heating to a low tempera- 

 ture and exposing a large surface to evaporation ; this is termed 

 condensed or evaporated milk. It is made in two forms : 

 sweetened condensed milk, which is a preparation of milk and 

 cane sugar ; and unsweetened condensed milk, which consists 

 of milk evaporated per se. 



The methods of manufacture are similar. In the manufacture 

 of sweetened condensed milk 1 J to 1J Ibs. of cane sugar are added 

 to each gallon of milk, and the mixture heated to such a tempera- 

 ture (80 to 85) that it will commence to boil at once on being 



