Production and Commerce—Flax is cultivated on the largest scale in Russia, from which country there was imported into the United Kingdom in 1872 linseed to the value of 3 millions sterling. The shipments were made in about equal proportion from the northern and the southern ports of Russia.
The imports from India in the same year amounted in value to £1,144,942, and from Germany and Holland to £144,108. The total import in 1872 was 1,514,947 quarters, value £4,513,842.
The cultivation of flax in Great Britain appears to be declining. The area under this crop in 1870 was 23,957 acres; in 1871, 17,366 acres; in 1872, 15,357 acres; and in 1873, 14,683 acres. The last named area reckoning the yield at 2 to 2½ quarters of seed per acre would represent a production of about 30,000 to 38,000 quarters.
In English price-currents, eight sorts of linseed are enumerated, namely, English, Calcutta, Bombay, Egyptian, Black Sea and Azof, Petersburg, Riga, Archangel. The first three appear to fetch the highest prices.
Uses—In medicine, linseed is chiefly used in the form of poultice which may be made either of the seed simply ground or of the pulverized cake. In either case the powder should not be long stored, as the oil in the comminuted seed is rapidly oxidized and fatty acids produced. An infusion of the seeds called Linseed Tea is a common popular demulcent remedy.
Adulteration—Linseed is very liable to adulteration with other seeds, especially when the commodity is scarce. The admixture in question is due in part to careless harvesting and in part to intentional additions. In 1864 the impure condition of the linseed shipped to the English market had become so detrimental to the trade that the importers and crushers founded an association called The Linseed Association of London, by which they bound themselves to refuse all linseed containing more than 4 per cent. of foreign seeds, and this step very rapidly improved the quality of the article.[402]
As the druggist has to purchase linseed meal, he must of necessity rely to some extent on the character of the oil-presser from whom he derives his supplies. The presence of the seeds of Cruciferæ (as rape and mustard) which is common, may be recognized by the pungent odour of the essential oil which they develope in contact with water. The introduction of cereals would also be easily discovered by iodine, which strikes no blue colour in a decoction of linseed. The microscope will also afford important aid in the examination of linseed cake or meal.
ZYGOPHYLLEÆ.
LIGNUM GUAIACI.
Lignum sanctum; Guaiacum Wood, Lignum Vitæ; F. Bois de Gaïac; G. Guaiakholz, Pockholz.