POWDERED MILK. 175 



yet devised gives a product exactly similar to the original 

 milk. 



Powdered Milk. Within the last few years methods of 

 preserving milk by reducing it to a powder have been 

 invented and perfected. There are several methods of 

 accomplishing this powdering of the milk, some of which 

 make use of a vacuum and others evaporate the milk with- 

 out a vacuum. In any case the milk, usually without the 

 fat, is thoroughly dried and subsequently passed through a 

 mill and ground into a fine powder. The material thus 

 obtained is much like flour, but is far more nutritious than 

 flour, inasmuch as the amount of proteid it contains is very 

 high, being very nearly 40%. The powder thus obtained 

 can be kept indefinitely if it is protected from moisture. The 

 bacteria that were present in the original milk are not killed 

 by the process, and they remain in the powder for a long 

 time in the condition for growth, but they cannot develop in 

 the powder, since it is dry and most of them soon die. The 

 milk powder which has been kept for some months contains 

 very few bacteria. The presence of these bacteria, however, 

 is a matter of no special significance, inasmuch as they cannot 

 multiply, and when the powder is subsequently dissolved in 

 water for use it is sure to be consumed so quickly that the 

 few bacteria left in the powder thus find no opportunity to 

 do any mischief. The milk powder thus produced is an 

 extremely valuable product, and can be used for a great 

 variety of purposes for which fresh milk has hitherto 

 been used. The material made by dissolving this powder 

 in water is not, however, exactly like fresh milk and will 

 never take its place. This method of preserving milk is par- 

 ticularly applicable to warm climates, for milk powder, if 

 kept dry, can be sent to any climate and preserved indefi- 

 nitely, being used anywhere and at any time that it is needed. 

 If the fat is retained the milk may be similarly dried, but the 

 product is somewhat different in character. It makes a 



