12 
BULLETIN 350, U. S. DEPARTMENT OF AGRICULTURE. 
seen the favorable effect of the refining process. The acetyl value 
of 20.3 in the crude pit oil was reduced to 3.45 in the refined oil. The 
kernel oil. however, shows a considerably higher acetyl value than 
the refined oil from the pits. This is due to the fact that the kernels 
were taken from pits which were not in fresh condition. 
The amount of unsaponifiable matter in an oil depends largely 
upon the amount of coloring matter and waxlike substances con- 
tained in it. Therefore, the crude oil would be expected to show* the 
highest percentage, which is substantiated by the results obtained. 
As previously stated, the insoluble acids are most important fac- 
tors in determining the quality and usefulness of an oil. Therefore, 
the physical and chemical constants of these acids were determined, 
and the results are presented in Table IV. For the purpose of com- 
parison, the known constants of a number of related oils are also in- 
cluded in Table IV. 
Table IT. — Physical and chemical constants of insoluble acids of oils from 
cherry pits and kernels and from other fruit kernels. 
Source of oil. 
Color. 
Odor. Taste. 
Spe- 
cific 
eravitv 
at25°C. 
Refrac- 
tive 
index 
at25°C. 
Congeal- 
ing point. 
Xeu- 
trali- Iod'n 
zation value. 
value. 
Cherry pits: 
Crude 
Refined.. 
Cherry ker- 
nels. 
Pale brown. 
do 
Pale straw. . 
Rancid, fatty. Bland, fatty, 
bitter. 
Slightly ran- Sweet ish,fatty, 
cid, fatty. bitter. 
Nut like, slight- Sweetish.fatty. 
ly rancid. slightlv bit- 
ter. 
0.9019 
.9137 
.9092 
1.4635 
1.4641 
1.4635 
° a 
12 to 11 
12.5 to 12 
13.5 to 13 
13. 5 to 13 
192.4 
179.7 
180.8 
205 
to 
209.9 
194 
99.9 
93.7 
92.8 
94.1 
nels. 1 
Apricot ker- 
nels. 2 
Prune ker- 
.9195 
to 
101.9 
99.4 
13 to 12 
11. S 
to 
11.3 
to 
i 103.8 
200.4 1 95.7 
nels. 5 
Mmnnri Ver- 
1.4461 
i to 
1 102 
204 1 93.5 
nels. 4 
to 
96.5 
i Lewkowitsch, J. Chemical Technologv and Analvsis of Oils, Fats, and Waxes, vol. 2, p. 232. London, 
1909. 
2 Specific gravity at 15° C. see Lewkowitsch, L, op. cit., p. 228. 
s Lewkowitsch, J., op. cit. .'p. 230. 
4 Refractive index at 60° C, see Lewkowitsch, J., op. cit., p. 237. 
Only slight differences in the physical properties — color, odor, and 
taste — of the insoluble acids are noted in the cherry oils. Data on 
these points were not available for the other oils. The specific grav- 
ity, refractive index, and congealing points of the insoluble acids of 
cherry oils compare favorably with the same constants of the related 
oils. The neutralization values differ somewhat from those of the 
related oils, with the excerption of the crude pit oil. This indicates a 
slightly different composition from the standpoint of fatty acids. 
The iodin value, which indicates the content of unsaturated acids, 
