History.—Rye is mentioned in the English version of the Old Testament [Exodus, ix. 32.]; but, in the opinion of Sprengel [Hist. Rei Herb. ii. 9, 1807.], spelt wheat is meant. The same writer also states that Theophrastus [Hist. Plant. lib. viii. cap. 9.] is the earliest author who notices the Secale cereale; but the word τιφη, used by Theophrastus, is thought by Fraas [Synops. Pl. Florae Classicae, pp. 306 and 307, 1845.] to refer to Triticum monococcum, and not to rye. Galen  mentions rye under the name of βριςα, the term by which, as well as by σικαλι, rye is known in modern Greece [Fraas. op. supra cit.; also, Pharm. Graeca, pp. 501 and 540, 1837. ]. Pliny [Hist. Nat. lib. xviii. cap. 39 and 40, ed. Valp.] speaks of secale or rye.
Botany. Gen. Char.—Spikelets two-flowered. Florets sessile, distichous, with the linear rudiment of a third terminal one. Glumes two, herbaceous, keeled, nearly opposite, awnless or awned. Paleae two, herbaceous; the lower one awned at the point, keeled, unequal sided, broadest and thickest on the outer side; the upper shorter and bicarinate. Stamina three. Ovarium pyriform, hairy. Stigmata two, nearly sessile, terminal, feathery, with long, simple, finely-toothed hairs. Scales two, entire, ciliate. Caryopsis hairy at the point, loose (Kunth).
Sp. Char.—Glumes and awns scabrous (Kunth).
Hab.—The Caucasian-Caspian desert. Cultivated in Europe; but little in England; frequently on the Continent.
Description.—Rye grains (caryopsides vel semina secalis vel frumenti), in external appearance, more resemble wheat than other cereal grains; but they are smaller and darker externally. Internally they are white and farinaceous; externally brownish. Like wheat, as found in commerce, they are devoid of their husk or paleae.
In order that the changes which rye undergoes when it becomes ergotized may be better understood, Corda [Beitrag zur Kenntniss der Brandarten der Cerealien und des Mutterkorns, in the Oekonomische Neuigkeiten und Verhandlungen, No. 83, Vienna, 1846.] has given the following description of the microscopic characters of healthy rye grains: "When we submit a thin transverse section of a healthy grain of rye to microscopic examination, we perceive that the seed-coat (Fig. 207, a) consists of three layers of thick-walled cells, beneath which we find the second, properly the third, seed-coat (207, b), composed of a single layer of thick-walled cells, having scarcely any cavity. Next follows a layer of cells containing gluten (207, c); and afterwards the cellular tissue of the albumen (207, d). This consists of large roundish hexagonal cells, which contain grains of starch (Fig. 208). The starch-grains (Fig. 209) are roundish or ellipsoidal, and about the 0.000150 of the Paris line in length."
Composition.—Rye has been analyzed by Einhof [L. Gmelin, Handb. d. Chem. Bd. ii. S. 1343.], by Boussingault [Quoted by Johnston, Lectures on Agricultural Chemistry.], by Fuerstenberg [Journ. f. pr. Chem. Bd. xxxi. S. 195.], and by Payen (see ante, p. 106). The proportion of starch and proteine compounds contained in it, as ascertained by Krocker and Hereford, have been before stated (see ante, vol. i. p. 119).
|Husk or bran||24.2||24||Starch||61.07||64.0|
|Husk||6.38||& salts 6.0|
|Undetermined acid and loss||5.42||2.0|
The composition of the ashes of rye is stated at p. 106.
1. Proteine Compounds. Fibrine, Glutin, and Albumen.—The so-called gluten of rye differs from wheat-gluten. It is not cohesive, and is soluble in water and alcohol; but after it has been dissolved in alcohol it is insoluble in water. It agrees in its properties with the glutin of wheat (see vol. i. p. 116, and ante, p. 100). Heldt [Ann. d. Chem. u. Pharm. Bd. xlv. S. 198, 1843.] considers it to be identical in composition with the other proteine compounds of rye analyzed by Dr. Bence Jones and Scheerer.
2. Starch. The starch of rye, like that of wheat, consists principally of large and small grains, with but few of intermediate size; the larger ones being, on the whole, somewhat larger than the corresponding ones of wheat [The following measurements of eight (including the largest and smallest) grains of rye starch were made by Mr. George Jackson:—1. 0.0016 of an English inch. 2. 0.0015. 3. 0.0013. 4. 0.0010. 5. 0.0005. 6. 0.0003. 7. 0.0002. 8. 0.0001.]. The shape of the larger grains is circular, flat, or lenticular; of the smaller ones globular (chiefly), ellipsoidal or ovoiclal, rarely angular or mullar-shaped. On the flattened surface of the larger grains is seen the central, rarely circular, usually slit, or 3-, 4-, or even 5- radiate hilum, sometimes surrounded by very faint concentric rings and delicate radiating lines. By polarized light the grains show a central cross.
Chemical Characteristics.—A cold decoction of rye forms with iodine the blue iodide of starch. By washing rye-dough with water, nearly the whole becomes diffused through the liquid, little more than husk or bran remaining behind. The milky liquid deposits on standing starch grains, and the decanted portion yields on evaporation the so-called gluten; from which, sugar is extracted by water, and oil by ether: the residue (glutin) is soluble in alcohol.
Physiological Effects.—In its nutritive qualities rye resembles wheat, especially in the fitness of its flour for making bread; but it contains less proteine matter and more sugar.
Uses.—Rye is employed dietetically and medicinally; and also in the distillery and brewery.
Rye-bread (in Germany called Schwartzbrod or black bread) is in common use among the inhabitants of the northern parts of Europe, but in this country is rarely employed. It is said to be more laxative (especially to those unaccustomed to its use) than wheat-bread; and hence is sometimes taken to counteract habitual constipation. The roasted seeds (semina secalis tosta) have been employed as a substitute for coffee. On the continent rye-flour and rye-bran are applied to the same medicinal uses that wheat-flour and wheat-bran are applied in England. Rye pottage (pulmentum vel jusculum secalinum) is said to be a useful article of diet in consumptive cases [Pearson, Pract. Synop. of the Mat. Alim. 91.].