2IO 



Condensed Milk and Milk Powder 



GRAVIMETRIC METHOD— PAPER COIL 

 "Make coils of thick filter paper, cut into strips 6.25 by 62.5 

 cm., and thoroughly extract with ether and alcohol, or correct the 

 weight of the extract by a constant obtained for the paper. From 

 a. weighing bottle or weighing pipette, transfer about 5 grams of 

 milk to the coil, care being taken to keep the end of the coil held 

 in the fingers, dry. Dry the coil, dry end down, on a piece of glass 

 at the temperature of boiling water; transfer to an extraction ap- 

 paratus, and extract with absolute ether or petroleum ether boiling 

 at about 45 degrees C. ; dry the extracted fat and weigh." 



SWEETENED CONDENSED MILK 



PREPARATION OF SAMPLE 



Pour the contents of the can into a bowl or on a 

 glass plate. Scrape out the can thoroughly, removing 

 all the sugar sediment from the top and bottom of the 

 can. Mix thoroughly with pestle or spatula until a 

 homogenous emulsion is secured. This is important, 

 as it is exceedingly difficult to secure a representative 

 sample otherwise. 



If it is desired to use a 40 per cent, solution as 

 directed in the determination of the individual ingred- 

 ients, weigh accurately 40 grams of the properly mixed 

 contents of the can into a 100 c.c. graduated flask. 

 Add 60 c.c. of water. The sweetened condensed 

 milk mixes somewhat difficultly with the water. 

 Complete solution is facilitated by adding the water in 

 several installments, shaking after each addition un- 

 til condensed milk sediment adheres no longer to the bottom and 

 sides of the flask. 



specific gravity 

 Aerometric Method, by Means of Beaume Hydrometer 



apparatus 



Beaume Hydrometer. — Use a specially constructed Beaume 



hydrometer with mercury bulb, and a scale of 30 to 37 degrees B. ; 



graduated to tenths degrees. Length over all, twelve inches ; length 



of spindel, six inches ; length of empty bulb, four and one-quarter 



Fig. 60. Electric 

 fat extractor 



Courtesy of 



E. H. Sargent 



& Co, 



