SOLID FATTY ACIDS OF COCO-NUT OIL. 285 
Having thus shown in this research the existence in coco butter of acids 
proved by others to be present, the process of converting the mixture of fatty 
acids into ethers, and separating these by fractional distillation, may be con- 
sidered generally applicable for the examination of ordinary oils and fats. 
In this investigation the chief difficulties met with were, first, in saponifying 
the coco-nut oil, when it was found that only by prolonged boiling with a 
weak lye, decomposing the soap, and boiling for a second time with caustic 
soda, was complete saponification effected ; secondly, there was great difficulty 
experienced in thoroughly drying the ethers, even phosphoric anhydride, as 
already mentioned, only removing the water after prolonged contact with them. 
Chloride of calcium was of no use for drying them, and baryta could not be 
employed, as at ordinary temperature it slowly decomposes the ethers. 
As before remarked, the accompanying diagram (Plate XX.) shows 
the ether-fractions after distillation had been carried on, until no longer any 
appreciable separation was effected. The rectangular areas represent the 
quantity in grms. of distillate between given intervals of temperature, whilst 
the curve represents what may be supposed to be the limit when the intervals 
of temperature are indefinitely diminished. 
Such a curve is obviously of a highly characteristic appearance, depending 
upon the nature of the simple fats and the proportion in which they occur in 
the original mixture ; and it is possible that curves such as this may be of use 
in identifying particular mixtures of volatile substances. 
VOL. XXVIII. PART II. 4 
