Nadia raised her hand, "The berries are the part used medicinally, collected when ripe and from which an acrid, nauseous, bitter juice is obtained by expression. From this juice, with the addition of sugar and aromatics, syrup of Buckthorn (Succus Rhamni) is prepared.



When freshly gathered in the autumn, the berries are about 1/3 inch in diameter, with the remains of a calyx beneath. The fruit is collected for use chiefly in the counties of Herts., Bucks. and Oxon, and is usually expressed in the locality where it is grown, by the collectors themselves, who sell the juice to the wholesale druggists, generally more or less diluted with water, the admixture being generally about 6 parts water to 1 of juice. From the dried berries, a series of rich but fugitive colours is obtained; the berries used to be sold under the name of 'French berries' and imported with those of Rhamnus infectorius from the Levant. If gathered before ripe, the berries furnish a yellow dye, used formerly for staining maps or paper. When ripe, if mixed with gum-arabic and limewater, they form the pigment 'Sap or bladder green,' so well known to water-colour painters. The bark also affords a yellow dye. "