The common Buckthorn grows in our woods and thickets, and used to be popularly known because of the purgative syrup made from its juice and berries. It bears dense branches of small green flowers, followed by the black berries, which purge violently. If gathered before they are ripe they furnish a yellow dye. When ripe, if mixed with gum arabic and lime water, they form the pigment called "Bladder Green." Until late in the present century-- _O dura ilia messorum!_--English rustics, when requiring an aperient dose for themselves or their children, had recourse to the syrup of Buckthorn. But its action was so severe, and attended with such painful gripings, that as time went on the medicine was discarded, and it is now employed in this respect almost exclusively by the cattle doctor. Dodoeus taught about Buckthorn berries: "They be not meet to be administered but to young and lusty people of the country, which do set more store of their money than their lives." The shrub grows chiefly on chalk, and near brooks. The name Buckthorn is from the German _buxdorn_, boxthorn, hartshorn. In Anglo-Saxon it was Heorot-bremble. It is also known as Waythorn, Rainberry Thorn, Highway Thorn and Rhineberries. Each of the berries contains four seeds: and the flesh of birds which eat thereof is said to be purgative. When the juice is given medicinally it causes a bad stomach-ache, with much dryness of the throat: for which reason Sydenham [70] always ordered a basin of soup to be given after it. Chemically the active principle of the Buckthorn is "rhamno-cathartine." Likewise a milder kind of Buckthorn, which is much more useful as a Simple, grows freely in England, the _Rhamnus frangula_ or so-called "black berry-bearing Alder," though this appellation is a mistake, because botanically the Alder never bears any berries. This black Buckthorn is a slender shrub, which occurs in our woods and thickets. The juice of its berries is aperient, without being irritating, and is well suited as a laxative for persons of delicate constitution. It possesses the merit of continuing to answer in smaller doses after the patient has become habituated to its use. The berry of the _Rhamnus frangula _may be known by its containing only two seeds. Country people give the bark boiled in ale for jaundice; and this bark is the black dogwood of gunpowder makers. Lately a certain aperient medicine has become highly popular with both doctors and patients in this country, the same being known as Cascara Sagrada. It is really an American Buckthorn, the _Rhamnus Persiana_, and it possesses no true advantage over our black Alder Buckthorn, though the bark of this latter must be used a year old, or it will cause griping. A fluid extract of the English mild Buckthorn, or of the American Cascara, is made by our leading druggists, of which from half to one teaspoonful may be given for a dose. This is likewise a tonic to the intestines, and is especially useful for relieving piles.