Buck-Thorn, or Rhamnus, L. a numerous genus of plants, consisting of 48 species, of which only two are indigenous, namely,

1. The catharticus, or purging buckthorn, a shrub growing in woods and hedges, very common in Shropshire. It attains, if cultivated, the height of 16 feet, flowers in May and June, and its fruit ripens about Michaelmas. Goats, sheep, and horses, eat the leaves, but cows refuse them. In our markets, the fruit of the blackberry bearing alder, and the dog berry tree, have lately been substituted for those of the buck-thorn. But this species of fraud may be easily discovered by opening the berries; for the genuine kind have generally four seeds, those of the alder two, and those of the dog-berry only one. Besides, buckthorn berries alone, when bruised on white paper, give it a green tint. The wood of this shrub is one of the finest for turnery, produced in this climate, as it sometimes grows to a size of six or eight inches in diameter. From the juice of the unripe berries, with alum, a yellow; and from the ripe ones, a fine green dye is obtained : the bark also strikes a yellow and brown-red colour. The juice of the unripe berries is of the colour of saffron, and is used for staining maps or paper: that of the ripe berries is the sap-green of miniature painters, and is much esteemed ; but if they are gathered late in autumn, the juice is purple,

Bechstein remarks, that the book-binders in Germany extract this colour by mixing the fresh juice with deep-red, or violet liquids, with which they dye the most beautiful sorts of paper and leather.

In medicine, buck-thorn berries have long been esteemed, and a syrup prepared from them is still kept in the apothecaries' shops, though seldom prescribed; as it occasions much sickness and griping. In a late Latin treatise, published by Dr. J. G. Kolb, of Erlang, 1794, the bark of the buck- thorn is much recommended as a mild, cheap, and efficacious remedy, in every respect preferable to the berries. After being exposed to the air, pr soaked in water, this bark soon assumes a yellow, orange colour. It contains a considerable proportion of gummy ingredients, which render it a tonic, gently astringent, and antiseptic medicine. The resinous extract is acrid and astringent, strongly purgative and resolvent: but the bark, in powder, mixed with honey, gum ara-bic, or any other mucilage, as well as a watery decoction of it, operates mildly, when taken in small doses, for the cure of intermittents : it may also be beneficially employed in slow, putrid, or nervous fevers, and in general debility after chronic diseases. Externally applied, in green wounds, laxity of the fibres, malignant foul ulcers, and in stopping the progress of mortification, this remedy possesses tonic, gently Stimulating and healing properties. The decoction is of great service in reducing inveterate inflammations of the eyes, and curing the itch; as it cleanses the skin, and abates the burning heat, without repelling the humours. But it should never be employed in ulcers that have arisen in consequence of erysipelas, or the rose: in other cases, its application will always be more safe, and attended with better effects, when it is at the same time used internally.

2. The frangula, or alder buckthorn, or black-berry bearing alder, grows in woods and moist hedges ; it generally attains a height of from six to ten feet. The wood of this shrub, when young, is soft and yellow, but becomes hard and light-red with age: its external bark is dark-grey, with white spots, but internally yellow; the branches contain an orange-coloured medullary tube. Its yellowish leaves appear late in May, or June, and sometimes a second foliage comes forth in autumn. The berries are at first d3rk-green, then become red, and at length black, when fully ripe; containing a sweet, though unpleasant juice. Goats devour the leaves with avidity, and they are also eaten by sheep : the flow-ers are particularly grateful to bees. The bark dyes yellow, and with iron, black. The berries gathered before they are ripe, dye wool green. Charcoal prepared from the wood, is preferred in making gun-powder. DAMBOURNEY made the following successful experiment with the ripe berries. He bruised them in cold water, and allowed the whole to undergo the vinous fermentation, which took place in eight days. This liquor he boiled for half an hour, and then dyed wool that had been previously prepared with bismuth: thus he obtained a very beautiful green colour, which he called a new, or native green, because it was not in the least affected either by strong vinegar, or a solution of potash. On adding a little sugar of lead to the dye, the vivacity of the colour was considerably increased.

The rind, boiled in milk, is asserted to be a safe and efficacious remedy for eruptions of the skin; yet we do not advise the reader to try experiments with this, or similar remedies, without consulting a medical friend. Decoctions of the bark in table-beer, are very certain and brisk purgatives, in dropsies, or constipations of the bowels of cattle.

Buck-Thorn, the Sea, or common sallow-morn, the Hip-pophce rhamnoides, L. is a very important shrub, growing wild on sandy shores, in various parts of the British coast, especially in Kent, Lincolnshire, and Yorkshire : it sometimes attains the height of eight or ten feet. Its bark is light-brown, the wood white, the small leaves of a sea-green colour, but silvery white be-low. The leaves appear early in spring ; the yellow flowers in June or July; the line red berries late in autumn.

In situations contiguous to the sea-shore, or the banks of rivulets, this shrub eminently deserves to be cultivated, as it is well calculated to bind a sandy soil, and to prevent the water from penetrating through banks and fences. It may be raised from seeds, but more expeditiously by planting layers, or propagating it from the very abundant spreading roots. On account of its thorny points, it affords excellent hedges, even on a ' sandy soil.

Although cows refuse the leaves of the sea buck-thorn, yet they are browsed upon by goats, sheep, and horses. The berries are strongly acid, with an austere vinous flavour : in Lapland, they are pickled and used as spice, but the fishermen of the Gulph of Bothnia prepare from them a rob, which, added to fresh fish, imparts a very grateful flavour.

From the leaves of this shrub, M. Suckow obtained an agreeable dark-brown dye for wool and silk, first treated with Vitriol of iron : Dambourney succeeded in producing a similar colour on cloth that had been previously steeped in a solution of bismuth.