CASTOR-OIL INDUSTRY. 



31 



part of the following day and the third day is finished by bleaching 

 and filtering. During this time the increase in the acidity is almost 

 negligible, increasing only about 0.1 of 1 per cent. An oil can 

 hold 0.15 per cent moisture without clouding, but when the moisture 

 runs up to as much as 1 per cent the moisture settles out and a 

 permanent cloud is formed. 



PROPERTIES OF THE OIL. 



The quality of castor oil is determined in the trade by its color, 

 clearness, and acidity. The best grade, designated as No. 1, is a 

 cold-pressed oil low in acidity, brilliantly clear, and approaching 

 colorlessness. Some cold-pressed oils are a very light straw color, 

 almost white; all hot-pressed oils are brownish yellow, while the 

 so-called No. 3 grade varies from dark brown to green. There is no 

 generally recognized No. 2 grade, since this was designated by only 

 a few dealers to represent some stock inferior to No. 1, but better 

 than No. 3. The specifications accompanying trade in this com- 

 modity usually consist of clearness, color, acidity, specific gravity, 

 iodin value, saponification value, odor, and taste. 



Table VIII. — Analyses of commercial samples of castor oil covering the period from 

 November, 1917, to December, 1918, and of expeller oils made at the Government plant 

 at Gainesville, Fla., in the spring of 1919 . 



Properties comparer!. 



Hydraulic-pressed oil. 



Expeller oil (series of more 

 than 100 samples). 





Range. 



Average. 



Range. 



Average. 



1 



2 



3 



4 



5 





0.961 to 0.965 0.9626 



0.9610 to 0.9634 



0.60 to 1.83 



6 82.7 



6 181.4 



61.0 



9620 



Acidity per cent. . 



Iodin number 



a 0.45 to 1.6 

 83.0 to 87.5 

 176.3 to 188 

 0.21 to 0.78 

 513 to 570 

 a 93 to 112 



1.22 

 85.6 

 182.5 

 .33 

 535 

 97.1 



.98 







T Jnsaponifiable matter per cent . . 





Flash point ° F . . 

















Properties compared. 



Expeller oil (series of 7 sam- 

 ples). 



Extracted oil. 





Range. 



Average. 



Range. 



Average. 



1 



6 



7 



8 



9 



Specific gravity (15.6° C.) • 



0.961 to 0.962 



0.85 tu 1.46 



80. 8 to 86. 1 



178 to 182 



0.20 too. 30 



524 to 527 



0. 9613 

 1.17 



84.2 

 179.6 

 .26 

 525 



0.9607 to 0.9624 

 a 3. 09 to 6. 66 



0. 9614 



Acidity per cent . . 



Tciiin number 



4.80 









TJnsaponifiable matter per cent . . 







Flash point ° F. . 













1 



a One higher value in each case was discarded as unrepresentative. 



6 One sample. 



