The corresponding decomposition of a glyceride into an acid and glycerin takes place when the glyceride is distilled in superheated steam, or by boiling in water mixed with a suitable proportion of caustic potash or soda.
As to the detergent action of a soap, Berzelius held that it was due to the free alkali liberated with water; but it is difficult to see why a solution which has just thrown off most of its fatty acids should be disposed to take up even a glyceride, and, moreover, on this theory, weak cold solutions, in which the hydrolysis is considerable, should be the best cleansers, whilst experience points to the use of hot concentrated solutions.
STEARIC ACID, n-Octodecylic acid CH 3 (CH 2) 16 CO 2 H, an organic acid found as its glyceride stearin, mixed with palmitin and olefin, in most tallows (hence its name, from Gr.
PALMITIC ACID, n-Hexadecylic Acid, Ch3(Ch2)14c02h, an organic acid found as a glyceride, palmitin, in all animal fats, and partly as glyceride and partly uncombined in palm oil.
Linoleic acid, C18H3202, found as glyceride in drying oils, and ricinoleic acid, C18H33(OH)02, found as glyceride in castor oil, closely resemble oleic acid.
Thus Japan wax is a glyceride and should be more correctly termed Japan tallow, whereas sperm oil is, chemically speaking, a wax.
A fat consisting of the glyceride of one fatty acid only, such as stearin or tristearin, C3H5(O C1811350)3, the glycerin ester of stearic acid, C17H35 C02H.
These three glycerides have been usually considered the chief constituents of most oils and fats, but latterly there have been recognized as widely distributed trilinolin, the glyceride of linolic acid, and trilinolenin, the glyceride of linolenic acid.
In addition to the fatty acids mentioned already there occur also, although in much smaller quantities, other fatty acids combined with glycerin, as natural glycerides, such as the glyceride of butyric acid in butterfat, of caproic, caprylic and capric acids in butter-fat and in coco-nut oil, lauric acid in coco-nut and palm-nut oils, and myristic acid in mace butter.
It is most conveniently obtained from olive oil, after removal of the oleic acid, or from Japanese beeswax, which is its glyceride.