98 LINEiE. 



hemp seed 80, and poppy seed 150, the raodius castrensis, equal to about 

 880 cubic inches/ The propagation of flax in Northern Europe as of 

 so many other useful plants was promoted by Charlemagne.^ It seems 

 to have reached Sweden and Norway before the 12th century.'^ 



Description — The capsule which is globose splits into 5 carpels, 

 each containing two seeds separated by a partition. The seeds are of 

 flattened, elongated ovoid form with an acute edge, and a slightly 

 oblique point blunt at one end. They have a brown, glossy, polished 

 surface which under a lens is seen to be marked with extremely fine 

 pits. The hilum occupies a slight hollow in the edge just below the 

 apex. The testa which is not very hard encloses a thin layer of 

 albumen surrounding a pair of large cotyledons having at their pointed 

 extremity a straight embryo. The seeds of different countries vary 

 from l to ^ of an inch in length, those produced in warm regions being 

 larger than those grown in cold. We find that 6 seeds of Siciliau 

 linseed, 13 of Black Sea and 17 of Archangel linseed weigh respectively 

 one grain. 



When immersed in water, the seeds become surrounded by a thin, 

 slippery, colourless, mucous envelope, which quickly dissolves as a 

 neutral jelly, while the seed slightly swells and loses its polish. The 

 seed when masticated has a mucilaginous oily taste. 



Microscopic Structure — On examining the testa under almond 

 oil or oil of turpentine, the outlines of the epidermal cells are not dis- 

 tinctly visible. But under dilute glycerin or in water the epidermis 

 quickly swells up to 3 or 4 times its original thickness ; on warming, 

 the entire epidermis is resolved into mucilage, except a thin skeleton 

 of cell- walls, which withstands even the action of caustic Ij^e. The for- 

 mation of the mucilage may be conveniently studied by the use of a 

 solution of ferrous sulphate, with which thin sections of the testa 

 should be moistened. Other structural peculiarities may be seen if 

 they are imbued with concentrated sulphuric acid, washed and then 

 moistened with a solution of iodine. The application of polarized light 

 is also useful. By the latter means crystalloid granules of albumi- 

 noid matter become visible if the sections are examined under oil. 

 The tissue of the albumen and the cotyledons abounds in drops of 

 fatty oil. 



Chemical Composition— The constituent of chief importance is 

 the fixed oil which the seed contains to about ^ of its weight. The 

 proportion obtained by pressure on a large scale is 20 to 30 per cent, 

 varying with the quality of the seed. The oil when pressed with- 

 out heat and when fresh has but little colour, is without unpleasant 

 taste, and does not solidify till cooled to - 20° C. The commercial 

 oil however is dark yellow, and has a sharp repulsive taste and 

 odour. On exposure to the air, especially after having been heated 

 with oxide of lead, it quickly dries up to a transparent A^arnish con- 

 sisting chiefly of Linoxyn, C*^H'^0^\ The crude oil increases in weight 



^ The English imperial gallon = 217 '27 Kulturpflanzenund Hau-tthicre . . . Berlin, 



cubic inches. 1870. 97, 430. 



^ For further historical information on ' Schtibeler, Die PJlanzenwelt Norwegens, 



flax in ancient times, we may refer to Hehii, Christiania, 1873 — 1875. p. 332. 



