The seeds of Cydonia vulgaris, Persoon (Cydonia europaea, Savi; Sorbus Cydonia, Crantz; Pyrus Cydonia, Linné).
COMMON NAME: Quince-seed.
ILLUSTRATIONS: Köhler's Medizinal Pflanzen, Vol. I, Plate 34; Bentley and Trimen, Med. Plants, 106.
Botanical Source.—This is a well-known shrub or tree, from 8 to 20 feet high. The leaves are oblong-ovate, obtuse at base, acute at apex, entire, smooth above, and tomentose beneath. The flowers are solitary, white with a purple tinge, large, and terminal. The pome or fruit is tomentose, obovoid, yellow when ripe, having a peculiar fragrance, and an austere, acidulous, astringent taste; cells 5; seeds many, in a thick, soluble mucus (W.—L.).
History.—The quince tree is a native of Candia, but is cultivated extensively in this country and Europe, and its fruit is much employed in making jellies, preserves, etc. It grows wild in the forests north of Persia, not far from the Caspian Sea, and south of Caucasus, and also in Anatolia (De Candolle, Origin of Cultivated Plants, 1882). De Candolle also states that the fruit has been but little modified by cultivation, being as harsh and acrid yet as when known to the ancient Greeks. The parts used in medicine are the seeds.
Description and Chemical Composition.—The seeds are ovate, acute, flat on one side, convex on the other, being compressed triangularly, brown externally, with a reddish tinge, internally white, odorless, and of a bland, mucilaginous taste when whole, but when the testa is removed from the dicotyledonous embryo, the taste of the latter is somewhat like that of bitter almonds. The external coat of the seeds is composed of very fine cells, in which is lodged a large quantity of mucilage, which is taken up by cold or hot water. The decoction, evaporated to dryness, and powdered, will form a proper mucilage with water, in the proportion of 3 grains to the fluid ounce. One part of it gives a semi-syrupy consistence to 1000 parts of water. Pereira proposed to call this mucilage cydonin; he considered it a peculiar variety of gum, which, like arabin, being soluble in cold or boiling water, is different from cerasin and bassorin. This mucilage gelatinizes with perchloride of iron, but, unlike that principle, it is not affected by silicate of potassium. It has but little adhesive qualities, contains albumen and calcium compounds, is precipitated by alcohol, mercuric chloride, zinc chloride, neutral and basic acetate of lead, but is unaffected by sodium biborate in solution. Its composition is C18H28O14 (Kirchner and Tollens, 1875), and it may be obtained in a dry state to the extent of 20 per cent. Oxalic acid may be derived from it by treatment with nitric acid. The cotyledons contain fixed oil, and malic acid is present in the fruit to the extent of 3 to 3.5 per cent. Sixty grains of quince seeds will make a thick mucilage in 30 minutes, of 8 fluid ounces of water.
Action, Medical Uses, and Dosage.—Decoction of quince seeds forms a demulcent mucilage, very useful in gonorrhoea, dysentery, aphthous affections, and excoriations of the mouth and fauces; also as a collyrium in conjunctival ophthalmia. A syrup prepared from the fruit, or the jelly, forms an agreeable article, either alone or added to drinks, for patients laboring under febrile diseases, diarrhoea, dysentery, and nausea. The following preparation rubbed upon the parts twice daily, has been recommended to discuss slow inflammatory deposits and tumors. Rx Quince seed ℥iv, alcohol fl℥viij. Macerate 20 days and express. Mix with an equal bulk of turpentine (Scudder, Spec. Med., 122). The mucilage should always be freshly prepared, as it sours readily.
Related Species.—Cydonia japonica, Persoon (Pyrus japonica, Thunberg); Japan quince. This beautiful shrub, cultivated for ornamental effect, has handsome crimson or fire-red flowers, an acidulous fruit possessing a somewhat spicy fragrance, and smooth, shining, coriaceous, serrated, ovate-lanceolate leaves, acute at each extremity. Properties probably similar to those of the preceding plant. It is a native of Japan, and blooms in April and May.