MILK AND DAIRY PRODUCTS PART 



instead of the unpleasant amyl alcohol, and to make the reading 

 of the column of fat easier the alcohol (sinol) is coloured red, 

 green, or blue. 



To make an analysis, the test-bottles are filled, in the 

 following order, with 



11 c.c. of Sinacid solution, 

 10 milk, 

 0*6 sinol, 



pipettes of the required size being used. The rest of the 

 operation is carried out as with the Gerber test-bottles, if 

 the "groove butyrometer" is employed. When the "valve 



butyrometer " is used, a 

 small piece of rubber 

 tubing must be pushed 

 over the valve before 

 the tube is filled. After 

 the reagents have been 

 filled in, the rubber stop- 

 per is fitted into the 

 test-bottle, which is then 

 violently shaken. The 

 test-bottles, after being 

 shaken, are placed in a 

 water-bath having a tem- 

 perature of 45 C. Before 

 placing the test-bottle in 

 the water-bath the band 

 of rubber tubing must 

 be pushed upwards so 

 that the small valve is 

 open. This is done to 

 prevent the pressure in 

 the test-bottle rising too 

 high. 1 The serum should 



now be perfectly clear, and free from any precipitate. The 

 free alkali of the solution serves to dissolve the casein, 

 whilst the tartrate prevents the precipitation of the lime 

 compounds, and so assists the separation of the fat. The 



1 Care must be taken to allow all the liquid in the ball of the butyrometer 

 to flow down into the graduated portion. 



FIG. 44. Water-bath and Test- bottles. 



