STERILIZATION OF MILK. 147 



long voyages, in mining districts, etc. That this industry 

 at the present is not insignificant, however, is apparent 

 from the fact that according to official statistics not less than 

 520,000 boxes were exported from Switzerland during 1888, 

 each one containing forty-eight one-pound cans of con- 

 densed milk. The value of this export article was calcu- 

 lated to be about half of the value of the export of Swiss 

 cheese from Switzerland. 



Two different methods are mainly used for the prepa- 

 ration of condensed milk. In the older one of these, 

 adopted, e.g., in the factories in Cham and Guni of the 

 Anglo-Swiss Company, sugar is added to the milk in the 

 process of manufacture. The main features of the method 

 are as follows : The milk is repeatedly heated to 158 

 176 F. (70 - 80 C.), and evaporated in vacuum-pans; 40 

 to 50 grams of cane-sugar is then added for every liter 

 (quart) of milk. By this method the milk is sterilized and 

 its water content reduced to only one fourth of the original 

 bulk. The final product is a thick, syrupy mass containing 

 all the nutritive components in the milk. Chemical analy- 

 sis of this condensed milk shows its composition to be 23 

 to 26 per cent water, 6 to 11 per cent fat, 8 to 10 per cent 

 casein, 53 to 57 per cent sugar, and 2 to 3 per cent ash. 



In the other and later method for condensing milk no 

 sugar is added, and the product does not therefore obtain 

 the exceedingly sweet taste which makes the condensed 

 milk prepared according to the former method objection- 

 able to many persons. This method is applied, for instance, 

 at the factory Schuttendobel near Hartzhofen in the Bava- 

 rian Algauer Alps, and is described in the following man- 

 ner: 



As soon as received the milk is cleaned from the dirt 



