qo MILK PRODUCTS 
mercial condensed milks usually represent whole 
milk concentrated to about one-third or two- 
sevenths of its original volume. A small amount 
of invert-sugar may be present. The most com- 
mon defect in condensed milks is deficiency 
in fat, due to preparation from closely skimmed 
milks. Preservatives (other than sucrose) and 
coloring-matters are rarely used, nor is it likely 
that foreign fats will be present. 
The fat of unsweetened condensed milk can be 
readily determined by the L-B method (page 18). 
In a recent publication, Bigelow andFitzgerald 
give the following detailed description of the 
application of the Leffmann and Beam method 
to the examination of unsweetened condensed 
milk: 
Weigh 9 grams of evaporated milk into an 
8% Babcock milk bottle. Add 10 c.c. of water. 
Thoroughly mix by shaking and add 3 c.c. of a 
mixture of equal parts of amyl alcohol and con- 
centrated hydrochloric acid. Shake thoroughly 
and add 10 c.c. of concentrated sulfuric acid 
(1.84 sp. gr.) in three or four portions, mixing 
after each addition. If too much heat develops 
the bottle may be cooled somewhat in water 
during the addition of the acid. 
Fill the bottle to near the base of the neck with 
a hot fresh mixture of equal parts of sulfuric 
acid and water. Thoroughly mix the contents 
