Fats which as linoleic

The mixed fatty acids are first separated into .several group by erystallisation from acetone, and then from light petroleum, at low temperatures, Each group of acids is analysed spectrographically before and after isomerisation with alkali, whence the proportions of α‐elueustearie and linoleic (and, if present, linoleuic) acids are determined. On the mixed fatty acids, the saturated acids are determined by the Bertram method, and palmitie acid by fractionation of the hydrogenated mixed esters. Oleic acid is determined by difference, since iodine values cannot be reliably employed where conjugated fatty acids are involved. With fatty acid mixtures very rich in elaeostearic acid, spectrographic analysis of the total fatty acids may lead to errors in the determined proportions of linoleic and other acids, and the preliminary low‐temperature resolution into several groups is essential. Two specimens of tung oil and the seed oils of Parinarium macrophyllum, Ricinodendron africanum , and Telfairia accidentalis have been studied by this procedure. All the oils contain elacostearic glycerides in varying proportions, but in no case was linolenic acid present. Saturated, especially palmitic, acids increase parallel with decrease, in the proportion of elacostearie acid, but the greater part of diminution in elaeostearic acid content is made up by increases in oleic and/or linoleic acid. The technical possibilities of the three Nigerian seed oils mentioned are discussed.