History—The quince was held in high esteem by the ancients, who considered it an emblem of happiness and fertility; and, as such, it was dedicated to Venus, whose temples it was used to decorate. Some antiquarians maintain that quinces were the Golden Apples of the Hesperides. The name Cydonia alludes to the town of Kydon, now Canea, in Creta; in the Talmud quinces are called Cretan apples.
Porcius Cato in his graphic description of the management of a Roman farmhouse, alludes to the storing of quinces both cultivated and wild; and there is much other evidence to prove that from an early period the quince was abundantly grown throughout Italy. Charlemagne, a.d. 812, enjoined its cultivation in central Europe.[1033] At what period it was introduced into Britain is not evident, but we have observed that Baked Quinces are mentioned among the viands served at the famous installation feast of Nevill, archbishop of York in 1466.[1034]
The use of mucilage of quince seeds has come to us through the Arabians; it is still met with in Turkestan.
Description—The quince is a handsome fruit of a golden yellow, in shape and size resembling a pear. It has a very agreeable and powerful smell, but an austere, astringent taste, so that it is not eatable in the raw state. In structure, it differs from an apple or a pear in having many seeds in each cell, instead of only two.
The fruit is, like an apple, 5-celled, with each cell containing a double row of closely-packed seeds, 8 to 14 in number, cohering by a soft mucilaginous membrane with which each is surrounded. By drying, they become hard, but remain agglutinated as in the cell. The seeds have an ovoid or obconic form, rather flattened and 3-sided by mutual pressure. From the hilum at the lower pointed end, the raphe passes as a straight ridge to the opposite extremity, which is slightly beaked and marked with a scar indicating the chalaza. The edge opposite the raphe is more or less arched according to the position of the individual seed in the cell. The testa encloses two thick, veined cotyledons, having a straight radicle directed towards the hilum.
Quince seeds have a mahogany-brown colour, and when unbroken a simply mucilaginous taste. But the kernels have the odour and taste of bitter almonds, and evolve hydrocyanic acid when comminuted and mixed with water.
Microscopic Structure—The epidermis of the seed consists of one row of cylindrical cells, the walls of which swell up in the presence of water and are dissolved, so as to yield an abundance of mucilage. This process can easily be observed, if thin sections of the seed are examined under glycerine, which acts on them but slowly.
Chemical Composition—The mucilage of the epidermis is present in such quantity, that the seed easily coagulates forty times its weight of water. By complete exhaustion, the seeds afford about 20 per cent. of dry mucilage, containing considerable quantities of calcium salts and albuminous matter, of which it is not easily deprived. When treated with nitric acid, it yields oxalic acid. After a short treatment with strong sulphuric acid it is coloured blue by iodine. Tollens and Kirchner (1874) assign to it the formula C₁₈H₂₈O₁₄, regarding it as a compound of gum, C₁₂H₂₀O₁₀, and cellulose, C₆H₁₀O₅, less one molecule of water.
Quince mucilage has but little adhesive power, and is not thickened by borax. That portion of it which is really in a state of solution and which may be separated by filtration, is precipitable by metallic salts or by alcohol. The latter precipitate after it has been dried is no longer dissolved by water either cold or warm. Quince mucilage is, on the whole, to be regarded as a soluble modification of cellulose.
The seeds on distillation with water afford a little hydrocyanic acid, and, probably, bitter almond oil.