:S2 ANNUAL. REPORT OF THE Off. Doc. 



Skim-milk is also a valuable food for liiiiuan beings, both in the 

 form of a beverage and in eooking. It should be used much more 

 extensively than it is. Unfortunately, dishonest milk dealers have 

 tried fraudulentlv to isell skim-milk as whole milk, so that the sale 

 of skim-milk has to be atte^ided with annoying restrictions. 



Skim-milk is also used in considerabh? quantities in the manufac- 

 ture of collage-cheese. 



Tlie casein of skim-milk is used for a variety of ijurjjoses, among 

 which may be mentioned, its use as sizing or dressing in the manu- 

 facture of paper as a substitute for celluloid, and as a constituent 

 of plastics for a great variety of purposes. 



24. Composition of Separator-Slime. 



The separator-slime, which collects on the walls inside the sepa- 

 rator-bowl, consists largely of milk-casein, in which are collected all 

 kinds of solid impurities contained in the milk, such as dust, fine par- 

 ticles of hay, ground grain, dung, cow^ hairs, etc. It is heavily loaded 

 with bacteria. The chemical composition of separator-slime is about 

 as follows: 



Per cent. 



Water, 67.0 



Fat, 1.0 



Casein, 26.0 



Milk-sugar 2.0 



Ash, 4.0 



On an average, 2,500 pounds of milk produce one pound of separator 

 slime. The amount increases with the amount of dirt present i«i the 

 milk. 



CHAPTER V. 



BUTTER-MAKING. 



In taking up the subject of butter-making, we assume that we 

 have the cream to start with. The question is sometimes asked 

 why it is necessary to remove cream from milk for butter-making, 

 why not churn the milk itself? Experiments in churning milk 

 have never succeeded in removing the fat from the milk at all com- 

 pletely and the method results in large losses of fat with conse- 

 quent decrease in yield of butter. 



