14 BULLETIN 350, U. S. DEPARTMENT OF AGRICULTURE. 



per cent, and the kernel oil 82.8 per cent. From the physical proper- 

 ties it is very probable that the bulk of the liquid acids consists of oleic 

 acid. The specific gravity of pure oleic acid is reported as 0.895 at 

 25° C. and the index of refraction at the same temperature as 1.4603. 

 These figures agree very closely with those recorded in Table V. The 

 descriptions of the acids obtained are also very similar to the descrip- 

 tion of official oleic acid, which is described as yellowish or brownish 

 yellow in color, with a peculiar lardlike odor and taste. 



That the bulk of the liquid acids consists of oleic acid is further 

 substantiated by the close agreement of the iodin value of these acids 

 as found in the cherry oils and the iodin value of commercial oleic 

 acid. Although the iodin value of the pure acid is 90, some oleic acids 

 of commerce have values as high as 100 to 110. 



The somewhat low neutralization values found in the cherry oils 

 are probably due to slight changes in the fatty acids, as it is well 

 known that these are apt to decompose. 



In approximating the composition of cherry oil, only the kernel oil 

 was considered. It was found that this oil consisted of 8.96 per cent 

 of solid acids, which were composed of stearic acid with a possible 

 trace of palmitic acid. Since the glycerid stearin contains 95.73 per 

 cent of stearic acid, it was found by calculation that the oil contained 

 9.36 per cent of stearin. The original oil consisted of 82.8 per cent of 

 liquid acids, which, calculated as oleic acid and reduced to terms of 

 olein (olein contains 95.7 per cent oleic acid), corresponds to 86.5 per 

 cent of the glycerid olein. 



A brief summary of the results obtained by the chemical examina- 

 tion indicates, therefore, the following approximate composition of 

 cherry kernel oil : Olein, 86.5 per cent ; ,stearin, including a possible 

 trace of palmitin, 9.36 per cent ; the remaining portion of the oil con- 

 sists of smaller amounts of free acids, volatile acids, and unsaponifi- 

 able matter. 



REACTION OF THE OIL TOWARD REAGENTS. 



Color reactions are frequently applied to fixed oils, although per- 

 haps more for the purpose of detecting adulterations than for deter- 

 mining the quality. Certain reagents produce characteristic color 

 reactions; therefore, when it is desired to compare related oils it is 

 often expedient to ascertain the behavior of the oils toward reagents. 

 Since this investigation deals with an oil which is closely related to 

 several well-known commercial oils, a number of color reactions were 

 therefore determined and comparison was made with the color reac- 

 tions obtained from the affiliated oils extracted by means of ether in 

 this laboratory. The results are presented in Table VI. 



