90 
IOWA ACADEMY OF SCIENCES. 
Benedict* and Lewkowitsche give the following con- 
stants for cotton seed oil: 
Specific Gravity 99° .8725 
Saponification Equivalent . . . 191 — 196.5 
Iodin Number 100 9—116.9 
The specific gravity is that found by Allen while the 
saponification equivalent is also the result of the investi- 
gations of that author. The Iodin number is that found 
by Wiley. 
COTTON SEED OILS. 
I. 
II. 
III. 
IV. 
V. 
VI. 
VII. 
VIII. 
IX. 
Specific Gravity 
• 90035 
.9005 
.9003 
• 9005 
.9005 
.9005 
.9003 
.9006 
.9005 
Volatile Acids 
. 3 i 5 
. 22 
.217 
■ 502 
. 872 
• 78 
.609 
• 557 
• 54 
Saponification (equivalent in mg, 
KOH for 1 gram. ) 
195.6 
198. 6 
194.4 
194.2 
195. 1 
194.9 
192. 1 
192. 1 
194. 8 
.Soluble Acids - 
.52 
.88 
• 53 
• 5 i 
i.8* 
2. 05 
i -47 
1.85 
.85 
Insoluble Acids 
Iodine Absorption 
95.48 
84. 83 
94.81 
88. 12 
95 - 61 
82. c8 
95.48 
86. 50 
94.08 
96.5 
94 - 58 
97-4 
94 - 73 
106. 2 
93 - 97 
106. 7 
94. 66 
101. 8 
It will be noticed that the specific gravity of the samples 
investigated varies from .9008 to .9006 and with an average 
of .90045. This is considerably higher than that given 
by either Allen or Benedict and Lewkowitsche. 
The limits of the value of the Saponification equivalent 
as given by Allen are very wide while the other authors 
give a more restricted limit for the constants of these oils. 
The results from the samples vary from 192.1 to 19S.6 
and with an average of 194.6, the better oils having the 
higher and the common oils the. lower values. 
In the Iodin number there is a great variation which 
depends largely on the nature of the oil, whether of the 
better grade or not. 
The common and crude oils gave results which came 
within the limits for the constants as stated by Allen and 
also Benedict and Lewkowitsche. 
The better grades of oils, however, give results for the 
Iodin absorption which are much lower than the limits 
given for the constants by the authors as quoted. 
The methods used in the investigation are those of the 
Association of Official Agricultural Chemists and pub- 
lished in bulletin No. 46 of the Division of Chemistry 
(revised edition). The results given are the average of 
three determinations for each sample. 
* Oil Fats and Waxes, p 306. 
