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 prune, or French plum, is the dried fruit of Prunus domestica, Linne, var. Juliana, de Candolle (N.O. Rosaceoe), a variety of the plum tree cultivated in France, especially in the valley of the Loire.
The plums are collected when ripe, and dried by exposing them to the sun for a day or two, after which the drying is completed in an oven or drying apparatus, the temperature being raised in stages from 45° to 90°. A more rapid process consists in drying in a special ' evaporator ' on wicker trays.
Prunes are of irregular flattened-ovoid shape, and about 3 cm. long. The surface is shrivelled and nearly black; the pulp, which should be soft and fleshy, is dark-coloured and surrounds a hard oval flattened stone; the latter is broadly rounded at one end and provided at the other with a shallow, slightly oblique depression. They have an agreeable odour and sweet fruity taste.
The best prunes are the French from the Loire districts, but California now exports large quantities of excellent fruit, and smaller amounts come from Bosnia, Spain, and Portugal.
The pulp contains about 40 per cent, of dextrose, about 2 per cent, of vegetable acids (malic, tartaric, &c), and about 30 per cent, of water, the composition varying with the season, degree of ripeness, etc.
The prune is nutritive, demulcent, and slightly laxative; it is frequently ordered as an article of diet in habitual constipation.