290 THE: MOJONNIER TEST 



(14) Place counterpoise for dish and the approximate weight 

 for fat on right hand balance pan. 



(15) Transfer dish to left hand balance pan and weigh quickly 

 to 0.10 milligram (0.0001 gr.). 



(16) Weight of fat divided 'by weight of sample taken, mul- 

 tiplied by 100, represents per cent butter fat. 



TOTAL SOLIDS DETERMINATION 



(1) The temperature of the hot plate in the solids vacuum 

 oven must be 100 degrees C. The temperature of the outside solids 

 plate must be 170 degrees to 180 degrees C. 



(2) To weighed milk in solids dish add about 1 c-c. water and 

 distribute mixture evenly over bottom of dish. For sweetened con- 

 densed milk use hot water. 



(3) Place not more than two dishes at once upon hot plate, 

 which must be perfectly level. Allow all visible moisture to evap- 

 orate. During the evaporation turn the dishes around with crucible 

 tongs, slowly, so as to produce an even boiling over the whole bot- 

 tom surface of the dishes. The dishes must be watched carefully 

 during the evaporation. This step should require not more than 

 two minutes. The end point is reached when bubbling and crack- 

 ling ceases and sample shows first trace of brown. Vigorous boil- 

 ing without spattering and complete evaporation are fundamentally 

 essential. 



(4) Place dishes into vacuum oven, which must be at 100 de- 

 grees C., and turn on the vacuum. Heat for ten minutes. In the 

 case of sweetened condensed milk keep it for twenty minutes in 

 vacuum oven. The gauge should register not less than twenty-two 

 inches of vacuum. If for any reason you cannot obtain at least 

 twenty-two inches of vacuum then leave dishes in oven for twice 

 the regular time. 



(5) Remove from oven and place into cooler. Allow dishes 

 to cool for five minutes. 



(6) Weigh dishes with covers on in the same manner that 

 the butter fat dishes were weighed, being careful to weigh quickly 

 and very exactly- 



(7) Weight of dry solids divided by weight of milk taken, 

 multiplied by 100, represents per cent total solids. 



