30 BULLETIN 769, U. S. DEPARTMENT OF AGRICULTURE. 
Taken all together, they constitute some 7,000,000 pounds, or 0.2 
per cent of our total fat resources, exclusive of butter. While it 
would perhaps be impossible to develop any of these in a short time 
to the point where they would add materially to our oil supply, it 
may be well to mention here some of the more common of these oils. 
Our importation of rape or colza oil dropped from about 20,000,000 
pounds in 1916 to only a little over 10,000,000 pounds in 1917. This 
oil is used very largely for lubricating purposes, but, ljke nearly all 
vegetable oils, it can be refined to form a fairly palatable food oil. 
The soap industry uses very appreciable quantities (Table 9). 
Closely related to rape oil is the oil obtained from mustard seeds, 
of which there are several varieties. Mustard oil, not the pungent- 
smelling, volatile oil, but the bland, fixed oil, can be used in foods, 
particularly in salad dressing. Undoubtedly a large part of the 
mustard oil produced in this country goes into our condimental 
dressings. A part of this oil is obtained as a by-product in the 
manufacture of mustard flour and prepared mustards, being expressed 
from the mustard seeds before they can be properly ground and bolted. 
In the grain elevators of the great Northwest, many hundred tons 
of wild oil seeds, principally brown mustard and charlock, are obtained 
in the screenings. One or two firms dealing in such miscellaneous 
products press these, and mix and market the oil Under the label 
"Vegetable Oil." This is sold to manufacturers of soap or other 
technical products. 
Sesame oil, one of the staple food oils of southeastern Europe and 
also produced to some extent in Mexico, is apparently coming into 
more common use in the United States. Recently a few hundred 
tons of sesame seed, known in Mexico as "Ajonjoli," have been 
pressed by southern oil mills, and a project is under way to import 
greater quantities as conditions in Mexico become more settled. 
Sesame would grow as far north as Ohio and Kansas. The harvest- 
ing of the seeds, however, requires a good deal of hand labor, for the 
little pods holding the seeds are readily shattered as soon as they are 
ripe, and, unless picked at exactly the right time and carefully 
handled, much loss occurs, because of the scattering of the seeds. 
Sunflower seed oil, which constitutes from 45 to 50 per cent of the 
seed of the large cultivated sunflower, has a pale yellow color, a mild 
taste, and a pleasant odor. In Russia, where large quantities of this 
oil are produced, the cold-drawn grade is used for culinary purposes 
and in making butter substitutes, while that which is hot pressed is 
employed in making soaps and Russian varnishes. The Russian 
peasants also use it as a burning oil. In 1911, more than 500 mills in 
the Caucasus were engaged in pressing sunflower seeds, and part of 
the oil thus obtained was exported to English refineries. Although, 
so far, no appreciable quantity of sunflower seed oil has been made 
