286 The; Mojonnier Test 



27. Cock, that switches vacuum from main Hne into vacuum 

 oven. Set of cocks at right is for soHds oven, set of cocks at left 

 is for fat oven- 



28. Hole in top of fat plate holder, communicating with suction 

 fan, on power unit. Run exhaust pipe on suction fan out of window 

 and keep hood over the dishes in order to drive all ether fumes 

 from room. 



29. Stool, to be screwed to floor. 



DIRECTIONS FOR OPERATING MOJONNIER TEST 



Preliminary directions for tests of both Fat and SoHds. (See 

 also list of precautions appended, pp. 292-294. 



(1) Wash solids dishes with warm water and fat dishes with 

 gasoline. Dry with a towel and place into heated vacuum oven for 

 five minutes with vacuum on. At the end of five minutes put these 

 dishes into cooler and, with the pump still running, keep them there 

 for five minutes before weighing. Do not turn off motor until last 

 dish is weighed out of cooling chamber. 



(2) While dishes are being heated and cooled, wash pipettes 

 with water, alcohol and ether and dry by applying vacuum at ex- 

 haust cock upon tester. Always use clean and dry pipettes for each 

 different sample. Aim to clean pipettes as well as all glassware, 

 immediately after using. 



(3) It is very important to keep extraction flasks clean. Wash 

 these with warm water immediately after extraction is finished. 

 Wash with washing powder and shot when necessary. 



(4) After aluminum dishes have been in cooler for at least 

 five minutes, weigh accurately to .0001 gram, using the proper coun- 

 terpoise. Weigh solids dishes with cover on. Fat dishes do not 

 have covers. Fat dishes should be cooled for seven minutes before 

 being weighed. 



( 5 ) Use weighing pipettes as follows : Fill five-gram pipette 

 up to five-gram mark for butter fat, and one-gram pipette up to one- 

 gram mark for total solids. If duplicates are to be run fill two 

 pipettes from the same sample. As pipettes are filled place lower 

 end into cleaned and dry rubber tubes which are pressed upon 

 knobs at ends and center of weighing cross. Either five or less 

 samples for butter fat or five or less for total solids m'ay be 

 pipetted out. 



