Chemical Composition—The fat under notice is composed, in common with others, of several bodies which by saponification furnish glycerin and fatty acids. Among the latter occurs also oleic acid,[390] contained in that part of the cacao butter which remains dissolved in cold alcohol as above stated. In fact by evaporating that solution a soft fat is obtained. But the chief constituents of cacao butter appear to be stearin, palmitin, and another compound of glycerin containing probably an acid of the same series richer in carbon,—perhaps arachic acid, C₂₀H₄₀O₂, or “theobromic acid” C₆₄H₁₂₈O₂, as suggested in 1877 by Kingzett.
Uses—Cacao butter, which is remarkable for having but little tendency to rancidity, has long been used in continental pharmacy; it was introduced into England a few years ago as a convenient basis for suppositories and pessaries.
Adulteration—The description given of the drug sufficiently indicates the means of ascertaining its purity.
LINEÆ.
SEMEN LINI.
Linseed, Flax Seed; F. Semence de Lin; G. Leinsamen, Flachssamen.>
Botanical Origin—Linum usitatissimum L., Common Flax, is an annual plant, native of the Old World, where it has been cultivated from the remotest times. It sows itself as a weed in tilled ground, and is now found in all temperate and tropical regions of the globe. Heer regards it as a variety evolved by cultivation from the perennial L. angustifolium Huds.
History—The history of flax, its textile fibre and seed, is intimately connected with that of human civilisation. The whole process of converting the plant into a fibre fit for weaving into cloth is frequently depicted on the wall-paintings of the Egyptian tombs.[391] The grave-clothes of the old Egyptians were made of flax, and the use of the fibre in Egypt may be traced back, according to Unger,[392] as far as the 23rd century b.c. The old literature of the Hebrews[393] and Greeks contains frequent reference to tissues of flax; and fabrics woven of flax have actually been discovered together with fruits and seeds of the plant in the remains of the ancient pile-dwellings bordering the lakes of Switzerland.[394]
The seed in ancient times played an important part in the alimentation of man. Among the Greeks, Alcman in the 7th century b.c., and the historian Thucydides, and among the Romans Pliny, mention linseed as employed for human food. The roasted seed is still eaten by the Abyssinians.[395]
Theophrastus expressly alludes to the mucilaginous and oily properties of the seed. Pliny and Dioscorides were acquainted with its medical application both external and internal. The latter, as well as Columella, exhaustively describes flax under its agricultural aspect. In an edict of the Emperor Diocletian De pretiis rerum venalium[396] dating a.d. 301, linseed is quoted 150 denarii, sesamé seed 200, hemp seed 80, and poppy seed 150, the modius castrensis, equal to about 880 cubic inches.[397] The propagation of flax in Northern Europe as of so many other useful plants was promoted by Charlemagne.[398] It seems to have reached Sweden and Norway before the 12th century.[399]