Caproic — Chambers's Encyclopaedia

Caproic, Caprylic, and Capric Acids are represented by the formulae $HC_6H_{11}O_2$ , $HC_8H_{15}O_2$ , and $HC_{10}H_{19}O_2$ , and are members of the acetic or fatty-acid series. They derive their names from capra, 'a goat,' in consequence of their more or less resembling in smell the odour of that animal. They may all be obtained from butter by pressing out the portion which remains liquid at $60^\circ$ ( $15.5^\circ$ C.), saponifying this oil, and distilling the soap which is thus formed with sulphuric acid. The liquid which passes over contains, along with butyric acid, these three acids, which, by being converted into baryta salts, are separable from one another. All three of these acids are also obtained by the oxidation of oleic acid by nitric acid; and capric acid is also obtained by acting upon oil of rue with fuming nitric acid; hence it is frequently called rutic acid. Each acid forms a series of salts, Caproates, Caprylates, and Caprates; but the inorganic ones, such as those containing barium, potash, and soda are of little importance. The Ethyl and Methyl salts, however, resemble each other, and by virtue of their pine-apple flavour, similar to that of Butyric Ether (q.v.), are sometimes used in the production of artificial fruit-essences.