280 MANUAL OF MILK PRODUCTS 



Reagents. 



Standard tenth normal silver nitrate solution. (Dissolve 

 17.5 grams of so-called chemically pure silver nitrate in water 

 and make the volume up to 1000 c.c.) 



Ten per cent solution of potassium chromate for indicator. 

 Making the test. 



Soften by warming to a pasty condition three or four ounces 

 of the butter in a fruit jar or wide-necked bottle. Mix thor- 

 oughly with a table knife or strip of wood in order to evenly 

 distribute the moisture. Weigh into a dish ten grams of the 

 mixed butter. Wash it with hot water into the pint bottle. 

 (If a moisture test was made on ten grams of the butter, the 

 substance remaining in the cup may be used for the salt test.) 

 Add enough hot water to bring the surface of the water up to 

 the 300 c.c. mark on the bottle. The melted fat should be above 

 the 300 c.c. mark. Place the stopper in the bottle and shake it 

 vigorously for about half a minute. Let the bottle rest for 

 about five minutes, then draw a Babcock milk pipette (17.6 c.c.) 

 of the watery portion and place it in a white cup. Add three 

 or four drops of the potassium chromate solution, stir, and run 

 in the standard silver nitrate solution from the burette, with 

 constant stirring until the color of the substance in the cup 

 changes to a permanent brownish red. Read on the burette 

 scale the amount of standard silver nitrate solution used. 



Each c.c. of standard silver nitrate solution used equals one 

 per cent of salt in the butter. 



WHEY BTJTTEK 



In sections of the country in which large quantities of cheese 

 are made, it is now customary to run the whey through a 

 separator, collecting the fat, which is then made into butter, for 

 in the making of cheese there is an appreciable amount of fat 

 which passes off in the whey. If this is removed by separation, 



