32 



BULLETIN 867, TJ. S. DEPARTMENT OP AGRICULTURE. 



An average of 54 analyses of commercial samples of No. 1 castor 

 oil manufactured by the leading crushers, covering the period from 

 November, 1917, to December, 1918, is given in Table VIII, columns 



2 and 3. These hydraulic-pressed oils are from cage presses and 

 represent the normal product regularly made. In columns 4 to 

 7 similar data are given for expeller oils made at the Government 

 plant at Gainesville, Fla., including more than 100 samples manu- 

 factured during the spring of 1919, and in columns 8 and 9 are 

 given the specific gravity and acidity of samples of extracted oil. 



That the refining of castor oil does not materially alter its chemical 

 characteristics other than merely to remove the acid is shown in 

 Table IX. Sample A represents a refined No. 1 oil the acidity of 

 which had risen to 10 per cent, while sample B is from a batch of No. 



3 oil chemically refined. 



Table IX. — Comparison of properties of representative samples of castor oils differing in 



acidity. 



Properties compared. 



Specific gravity 



Flash point °F . 



Fire do. . . 



Pour test do . . . 



Viscosity at 212° F seconds. 



Ash 



Total saponification . 



Odor 



Water 



Appearance 



Iod in value. 

 Solubility.. 



Sample A. 



/Atl5.25Be' 



\0.9643 



555 , 



630 , 







100 to 101. 



C 1 ) 



180.85 



Castor 



Trace 



Light yel- 

 low, pale 



87 



O.K... 



Sample B . 



JAtl5.70Be\ 

 \0.9613. 



555. 



615. 



0. 



96 to 97. 



( 2 ). 



182.48. 



Castor. 



Trace. 



Light 

 green. 



91. 



O.K. 



1 Trace, considerable alkalinity, but no sulphates. 2 Trace, slight trace of alkalinity, but no sulphates. 



The following is an analysis of a single sample of No. 1 expeller oil 

 containing properties not determined in the foregoing analyses: 



( '< .lor Straw, very slight cloud. 



Odor Mild. 



Specific gravity at 15.6° C. (60° F.).. 0.963 = 15.4° Be. 



Solubility in 90 per cent alcohol Completely soluble. 



Acid number 1.9 = 1 per cent free acid (as oleic). 



Iodin number 82.7. 



Saponification number 181.4. 



Viscosity 98.6. 



Unsaponifiable matter (per cent). .. 1.0. 



Rosin None. 



Adulterants None detected. 



Samples of castor oil from various sources were heated to 400° F. 

 for 1 hour to ascertain the effect of heating on the acfdity. These 

 results are given in Table X, and are reported as the percentage of 

 acidity expressed as oleic. 





