CASTOR-OIL INDUSTRY. 33 
TABLE X.—Analyses of castor oils from various sources, showing the effect of heating upon 
acidity. 
Acidity (per cent). 
Description of sample. 
Control. | Heated. 
Refined No. 1 OE eas eee ce oe oe ee Hei aoe RS cereal 0. 47 0. 58 
Oe NO sal 0 Urs set Sera epg ie ie icine elec wie a Sinn sd wias Sodio wisi BS ace ae eee 1. 00 1.05 
IRGHECINIGFEO) ll Rasa eh Gs amg ese SOB eS BCR OC eI cs SER eee gain ears eer 71 79 
IRGC INGE APOE AES ASE 5 OSs oe SS Se SSS CSI eo ees ce ee 92 96 
It is thus evident that heat alone has little effect on the acidity. 
This question arose from the possibility that if such acidity did 
develop, it might operate to pit the walls of the gas-engine combustion 
chamber during a run. 
When the Bureau of Aircraft Production went into the market for 
castor oil for lubricating purposes it drew up the specifications 
listed below, giving the properties which a good grade of lubricating 
castor oil should possess. Since these properties are possessed only 
by a high-grade No. 1 oil, these specifications may be accepted as 
fairly representative of this entire grade, regardless of its intended 
use. 
General.—(1) This specification covers the requirements of the Bureau of Aircraft 
Production in all purchases of castor oil for rotary-engine lubrication. The oil must 
be a high-grade vegetable castor oil suitable for this purpose. Both cold-pressed 
vegetable castor oil and hot-pressed vegetable castor oil which has been refined so 
that it will meet the requirements of this specification may be submitted for purchases. 
(2) The castor oil must be free from adulteration, other oils, suspended matter, grit, 
and water. (3) The castor oil must meet the following requirements: 
Color.—(4) When observed in a 4-ounce sample bottle, the castor oil must be color- 
less or nearly so, transparent, and without fluorescence. 
Specific gravity.—(5) The castor oil must have a specific gravity of 0.959 to 0.968 at 
60° F. (Baumé gravity must be from 16.05 to 14.70 at 60° F.) 
Viscosity.—(6) The castor oil when tested in a Saybolt universal viscosimeter must 
have a viscosity of not less than 450 seconds at 130° F. and 95 seconds at 212° F. 
Flash point—(7) The flash point must not be less than 450° F. in a Cleveland 
open-cup flash tester. 
Pour test.—(8) The castor oil, in a 4-ounce sample bottle one-quarter full, must 
not congeal on being subjected to a temperature of plus 5° F. for one hour. (See 
specification No. 3525, ‘‘ Pour test.’’) 
- Evaporation test—(9) The castor oil must not show a greater loss than five-tenths 
of 1 per cent when heated in an oven at 230° F. for 1? hours. This test shall be made 
on a 5-gram sample in a glass crystallizing dish approximately 24} inches in diameter 
and 14 inches high, inside dimensions. 
Ash.—(10) The castor oil shall not show more than 0.015 per cent of ash and shall 
ohow no impurity of any sort not related to the original product. 
Solubility.—(11) The castor oil must be completely soluble in 4 volumes of 90 
per cent alcohol (specific gravity 0.834 at 60° F.). This test shall be made on a2 c. c. 
sample. = 
