This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
The quince is the fruit of Pyrus Cydonia, Linne (N.O. Rosaceoe), a small tree indigenous to Persia, but distributed by cultivation throughout central Europe and other warm countries; the seeds are imported chiefly from Cape Colony.
The fruit, which resembles a pear, contains five carpellary cavities, in each of which there are about twenty seeds closely packed in two vertical rows. These seeds are separated from the ripe fruit and dried; being coated with mucilage they adhere more or less firmly together.
Quince seeds bear a general resemblance to apple pips. They are of about the same size, and of a similar mahogany-brown colour. By the mutual pressure to which they are subjected in the fruit, quince seeds, however, are distinctly flattened on the two larger sides, whilst of the two narrow sides or edges one is obtuse and boldly arched, the other only slightly curved and often provided with a distinct acute ridge. They frequently adhere firmly to one another in small irregular masses or in two more or less regular rows, being cemented together by dry mucilage, which is visible in the form of whitish flakes on the surface of the seeds and in the interstices between them. This mucilage is derived from the cells of the epidermis of the seed-coat in which it is stored. (Compare fig. 92, E).
The seeds are pointed at one end, where the hilum may be distinguished as a minute paler spot, and obtuse at the other (the chalazal extremity). Transverse sections through the seed, which is rather hard, exhibit two firm, yellowish white cotyledons with a very narrow endosperm. The kernel possesses a taste resembling that of bitter almonds, but much fainter. The seed-coats, when chewed, are simply mucilaginous.
The student should observe
(a) The angular shape of the seed,
(b) The dry mucilage which cements them together,
(c) The taste of the kernel and seed-coats.
Fig. 92. - Quince seed. A, the seeds cemented together by mucilage, natural size. B, a single seed, natural size. C, the same, softened in water and magnified 3 diam. D, transverse section of B. E, portion of the same, magnified 190 diam.; o-, the epidermis, in which the mucilage is secreted; v, endosperm. (Berg).
The principal constituent of quince seeds is the mucilage, of which they are said to yield as much as 20 per cent. It is contained in the cells of the outer epidermis of the seed-coat, and swells and dissolves when the seeds are soaked in water. The seeds also contain about 15 per cent, of fixed oil and probably a small proportion of amygdalin and of emulsin since they evolve an odour resembling that of bitter almonds when they are crushed and mixed with water.
Quince seeds have been employed as a demulcent, but are not now much used medicinally in this country.