THE MOJONNIER TEST 371 



washed away. It is of the utmost importance to shake thor- 

 oughly at this point. 



(4) Add 25 c.c. ethyl ether, insert cork and shake vigorous- 

 ly, lengthwise of flask, with liquid in large bulb of flask, and 

 small bulb extended upward. Stop shaking at end of five seconds 

 until all liquid has run into large bulb and repeat vigorous shak- 

 ing for four five-second periods. 



(5) Add 25 c.c. petroleum ether and shake in same way. 



(6) Place extraction flasks into centrifuge and whirl for 

 thirty turns at speed of about 600 R. P. M. Double time for 

 sweetened condensed mjlk. 



(7) Place four 3^-inch dishes in line on shelf adjoining hot 

 plate, keeping them in order in which their weights were posted 

 upon record sheet. Aim to have numbers on flasks correspond 

 with number of dishes. 



(8) Pour ether extraction to dividing line into proper dishes 

 and slide dishes over onto hot plate, which should be held at a 

 temperature of 135 degrees C., as indicated by thermometer, in- 

 serted in nickel plated mercury well. 



(9) Repeat the extraction, adding first alcohol enough to 

 bring line close up to top of small neck of flask, then 25 c.c. 

 ethyl ether, and then 25 c.c. petroleum ether, and shake vigorous- 

 ly after the addition of each of above three reagents for four 

 5-second periods. 



(10) Whirl in centrifuge for thirty turns. 



(11) Move aluminum dishes back upon shelf adjoining hot. 

 plate and pour the second extraction into proper dishes. Never 

 pour extraction into hot dish. Remove dish from hot plate as 

 soon as ether is all evaporated. 



(12) When all of ether has evaporated place dishes into 

 vacuum oven, which should have a temperature of 135 degrees 

 centigrade. Keep them there for five minutes after the vacuum 

 gauge shows at least twenty-two inches of vacuum. 



(13) Place dishes into cooler for seven minutes, with pump 

 outfit running. See that water is running through cooling plates. 



(14) Place counterpoise for dish and the approximate 

 weight for fat on right hand balance pan. 



