10 BULLETIN 1054, U. S. DEPARTMENT OE AGRICULTURE. 
A serious difficulty encountered in the removal of the solvent was 
the tendency of the oils to foam when the last portions of the benzol 
were being removed. This foaming was much more severe in the 
extracts from the dry-process germs, due possibly to the presence 
of more starchy matter in such material than in the germ stock sepa- 
rated by the wet process, in which all the starch is removed by thor- 
ough washing. The presence of the starch also makes the benzol 
extracts from the wet-process germs exceedingly difficult to filter. 
For purposes of convenience the several oils will hereafter be 
designated as follows: A, Wet-process germ by expeller: B. wet- 
process germ by solvent; O, wet-process cake by solvent; D\ 
dry-process germ by expeller; E, dry-process germ by solvent; 
F. dry-process cake by solvent. 
APPEARANCE AND CHARACTER OF THE CRUDE OILS. 
Samples of the two expeller oils and the four benzol-extracted 
oils were placed in standard 5^ inch bottles for the purpose of com- 
paring the color and other characteristics. Some of the oils, espe- 
cially the benzol-extracted oils from the oil cake, appeared to be 
somewhat turbid when cold, although they were filtered clear while 
warm. For this reason the samples were allowed to stand in a dark 
place for a month and their condition then noted. Table 3 sum- 
marizes the appearance of the oils. 
Table 3. — Color and appearance of crude com oils in standard 51-inch bottles 
after standing in the dark for one month. 
Oils. a 
Color. Clarity, deposit of solids, etc. 
Sample D, dry-process germ by expeller. .. | Bright golden "\ ery slight whitish deposit. 
Sample E , drv-process germ by solvent Tdo About >-inch whitish deposit. 
Brieht golden, with reddish Very slight whitish deposit. 
tinge. 
Slightlv more reddish than About |-inch whitish deposit, 
oil A. 
Reddish yellow J-inch dark brown deposit. 
Reddish brown Hnch light brown deposit. 
Sample A, wet-process germ by expeller... 
Sample B, wet-process germ by solvent. . . 
Sample F, dry-process oil cake by solvent. 
Sample C, wet-process oil cake by solvent. 
a The samples of oil are arranged according to their depth of color, lightest to darkest. 
It will be noted that the oils from the dry-process material are 
on the whole somewhat lighter in color than the other oils. However, 
the same oils also appear to have the heaviest deposits of solids. 
While, no doubt, some stearin is present in these deposits, yet from 
the fact that the oils from the dry-process germ material contain the 
heaviest deposits it may be assumed that a portion of these solids is 
starchy material. The benzol-extracted oils from the oil cakes deposit 
by far the greatest quantity of solid matter. 
The free fatty acid content of each of the oils was determined, and 
the results are shown in Table -i. 
