292 THE MOJONNIER TEST 



TOTAL SOLIDS DETERMINATION 



(1) Use .3000 gram sample- Add 2 c.c. distilled water to 

 the sample in this dish. Mix milk powder and water thoroughly 

 with the blunt rod. 



(2) Continue the determination as under evaporated milk, 

 but continue heating in the vacuum oven for twenty minutes. 



LIST OF PRECAUTIONS TO OBSERVE IN OPERATING 

 MOJONNIER TESTER 



(1) Before the reagents are put into the cans be sure that 

 the cans are thoroughly cleaned by washing all parts first with warm 

 water, then alcohol and then ether. Every third or fourth time 

 cans are filled, empty out last portion of reagents and use for clean- 

 ing purposes. 



(2) The bottom of all dishes should be kept as flat as possible. 

 Any bulging may be worked out by resting dishes upon marble plate 

 in front of balance, rubbing entire bottom surface with thumbs. 

 Operator should observe this every time dishes are cleaned. This 

 is very important. 



(3) The calcium chloride in the coolers should be changed 

 every three or four weeks. The same calcium chloride may be 

 used over and over by drying the used calcium chloride in the tin 

 dishes placed upon hot plates held at 135 degrees centigrade for 

 at least 5 hours. 



(4) The bottles should be whirled in the centrifuge until the 

 ether extraction is perfectly clear. About 30 turns at a normal 

 speed is to be recommended. For sweetened condensed milk this 

 time must be doubled. 



(5) Be sure to keep extraction flasks perfectly clean. Wash 

 often with sulphuric acid and washing powder, if necessary. If 

 particles cling to the sides put in small shot, washing powder, and 

 hot water and shake thoroughly. 



(6) Keep temperature regulated as nearly to standard tem- 

 perature as possible. 



(7) Never pour off extraction into a hot dish. Remove dish 

 from plate before second extraction is run into dish- 



