94 MILK PRODUCTS 
found that two tests devised for detection of 
rosin-oil can be satisfactorily adapted to detec- 
tion of palm oil. Success depends on several 
points. The sample must be kept in a cool 
dark place until used, filtered at a temperature 
not above 70°, the heating as brief as possible, 
and promptly tested. The reagents must be 
pure and colorless. Cochran finds that annatto 
will simulate palm oil in these tests, and hence 
the absence of the former must be assured 
(see above) before inferring the presence of the 
latter. 
Halphen method.—1o0 c.c. of the filtered fat 
are dissolved in 300 c.c. petroleum spirit and 
shaken out with 50 c.c. of potassium hydroxid 
solution (0.5 % of hydroxid). The water is drawn 
off, made distinctly acid with hydrochloric acid, 
and shaken out with 10 c.c. of carbon tetrachlorid. 
This solution is drawn off, and part of it tested 
by adding to it 2 c.c. of a mixture of 1 part crys- 
tallized phenol in 2 parts carbon tetrachlorid. To 
this add 5 drops of hydrobromic acid (sp.gr. 1.19). 
The test is best performed in a porcelain basin and 
the contents mixed by agitating gently. _ Palm oil 
gives almost immediately a bluish-green liquid. 
Liebermann-Storch method.—r1o c.f. of the 
filtered fat are shaken with an equal volume of 
acetic anhydrid, one drop of sulfuriq acid (sp. 
gr. 1.53) is added and the mixture shaken for 
{ 
| 
; 
