BUTTER. 71 



them throughly washed with water, alcohol and ether, 

 wiped perfectly dry on the outside, and heated for one 

 hour to boiling temperature. The flasks should then 

 be placed in a tray by the side of the balance and cov- 

 ered with a silk handkerchief until they are perfectly 

 cool. They must not be wiped with a silk handker- 

 chief within fifteen or twenty minutes of the time they 

 are weighed. The weight of the flasks having been 

 accurately determined, they are charged with the melt- 

 ed fat in the following way: 



A pipette with a long stem, marked to deliver 5.75 

 c. c. is warmed to a temperature of about 1 3<DF. The 

 fat having been poured back and forth once or twice 

 into a dry beaker in order to throughly mix it, is taken 

 up in the pipette and the nozzle of the pipette carried 

 to near the bottom of the flask, having been previously 

 wiped to remove any adhering fat, and 5.75 c. c. of fat 

 are allowed to flow into the flask. After the flasks 

 have been charged in this way, they should be recover- 

 ed with the silk handkerchief and allowed to stand 

 fifteen or twenty minutes, when they are again weighed. 



The saponification. Ten c. c. of 95 per cent, alcohol 

 are added to the fat in the flask, and then 2 c. c. of the 

 concentrated soda solution; a soft cork stopper is now 

 inserted in the flask and tied down with a piece of 

 twine. The saponification is then completed by- plac- 

 ing the flask upon the water or steam bath. The flask 

 during the saponification, which should last one hour, 

 should be gently rotated from time to time, being 

 careful not to project the soap for any distance up its 



