34 BULLETIN 867, U. S. DEPARTMENT OF AGRICULTURE. 
Acid number.—(12) It must not require more than 3 milligrams of potassium 
hydroxid (KOH) or 2.14 milligrams of sodium -hydroxid (NaOH) to neutralize 1 
gram of oil. This is equivalent to 1.5 per cent of oleic acid. 
-Unsaponifiable matter.—{13) The unsaponifiable matter must not exceed - per 
cent. Samples used for this test shall weigh 5 to 10 grams. 
Todin number (Hanus or Wijs methods).—(i4) The iodin number must be between 
80 and 90. Samples used for this test shall weigh 0.2 to 0.25 gram and shall be treated 
for } hour. 
Rosin (Lieberman-Storch test).—(15) The castor oil must not give a reaction for either 
rosin or rosin oil. 
Cottonseed oil ( Halphen test) —(16) The castor oil must not give a reaction for cotton- 
Seed oil. 
Inasmuch as the chemical analysis does not give the final word 
regarding the adaptability of an oil for lubricating purposes, engine 
tests have been made on the lubricating value of No. 1 hydraulic- 
pressed oil, No. 1 expeller oil, and No. 3 refined oil. The results of 
such tests show these oils to be of equal value for lubricating pur- 
poses. Since the chemical and physical constants expressed above 
are practically identical, it follows that color is the only evident 
means of differentiating between the various oils. A demulsibility 
test applied to hydraulic-pressed oil compared with expeller oil 
reacted slightly in favor of the expeller oil. The difference, however, 
was so slight that the two oils may be considered in this respect 
eee aly identical. 
The following statements quoted from leading dealers in castor 
oil (not pr intinciaece show how the trade considers American- 
produced oil as compared with various imported stocks: 
The American-pressed castor oil will remain free from rancidity for a longer period 
than the imported oils and as a general average is vastly superior to any imported oil 
that we have received. 
The oil that comes irom China and the Far East seems to be of a decided yellow color 
and. in the writer’s judgment, would indicate that it is hot pressed, i. e., that the oil 
was pressed from a warm or hot meal. 
In our opinion the oil made in the United States is equal, if not superior, to the im- 
ported. 
We will say that it has happened that the oil we purchased which was made in this 
country turned out to be better than that we have used which was made abroad. 
Domestic-manutfactured castor 011 will keep longer and be ireer from acidity than the 
oil which is imported. Generally speaking, the imported castor oil, especially from 
the Orient, contains from 1 to 8 per cent acidity and by keeping the oil the acidity 
is likely to be increased, especially where the oil tests from 3 or 4to 8 percent. We 
look upon the domestic-manuiactured white oil as being best not only for medicinal 
but for manufacturing purposes. 
Asa matter of fact, now that the War Trade Board has ruled (January, 1919) that 
castor beans and castor oil can come freely into this country, we doubt if any of 
this oil (oriental) willcomehere. Itis,as you may know, an inferior oil, and can only 
be used in comparison with a domestic production of No. 3 castor oil. 
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