BUTTER 87 
with alcohol and then with ether, and thoroughly 
dried by heating in the water-oven. After 
cooling, it is allowed to stand for about fifteen 
minutes and weighed. (In ordinary operation 
this preparation of the flask may be omitted.) 
A pipet, graduated to 5.75 c.c., is heated to about 
60° and filled to the mark with the well-mixed 
fat, which is then run into the flask. After 
standing for about fifteen minutes the flask and 
contents are weighed. 20 c.c. of the glycerol- 
soda are added and the flask heated over the 
Bunsen burner. The mixture may foam some- 
what; this may be controlled, and the operation 
hastened by shaking the flask. When all the 
water has been driven off, the liquid will cease 
to boil, and if the heat and agitation be continued 
for a few moments, complete saponification will 
be effected, the mass becoming clear. The whole 
operation, exclusive of weighing the fat, requires 
about five minutes. The flask is withdrawn from 
the heat and the soap dissolvedin 135 c.c. of water. 
The first portions of water should be added drop 
by drop, and the flask shaken between each 
addition in order to avoid foaming. When the 
soap is dissolved, 5 c.c. of the dilute sulfuric acid 
are added, a piece of pumice dropped in (this 
must not be omitted), and the liquid distilled 
until 110 c.c. have been collected. The con- 
densing tube should be of glass, and the distilla- 
7 
