70. The BUCK-THORN (Rhamnus catharticus) is a spinous shrub, which grows in thickets and hedges, and has clusters of small green flowers, globular black berries, and somewhat oval leaves, serrated at the edge.
About the month of September the berries of the buck-thorn begin to ripen; and, if these are bruised when perfectly ripe, they yield a green tint. They are made into the sap-green which is used by painters in water-colours, by evaporating their juice to the consistence of a gum. From the juice of the unripe berries, mixed with alum, a yellow dye is obtained, which is employed by dyers, and also for staining maps or paper. If the fruit be gathered late in the autumn the juice is purple. The syrup of buck-thorn berries is sometimes used in dropsies and other complaints, though there are objections to it from its occasioning sickness and griping. The berries have a faint disagreeable smell, and a nauseous bitter taste. It is not unusual to mix with, or substitute for them, the fruit of the berry-bearing alder, and of the dog-berry tree. The fraud is, however, easily detected on examination; for the buck-thorn berries have each four seeds, which the others have not.
The inner bark of the buck-thorn is said to yield a medicine preferable to that afforded by the berries, but it is an extremely powerful one.
71. NUX VOMICA, or VOMIC NUT, is a round, flat seed, about an inch in diameter, of greyish brown colour, and horny consistence, the produce of a tree (Strychnos nux vomica) which grows in the East Indies.
The tree is of large size, and has somewhat oval leaves, in pairs, each marked with three or five strong ribs. The young branches have swelled joints. The flowers are in a kind of umbels at the extremity of the branches.
The fruit which produces the vomic nut is a species of berry, about the size of a small apple, and covered with a hard substance somewhat resembling that of the pomegranate ([154]), and of beautiful orange colour when ripe. This fruit is filled with a pulp which contains the seeds.
There is so great a consumption of nux vomica, that the quantity vended at the East India Company's sales, in 1808, was about five tons' weight, and its price about nineteen shillings per hundred weight, exclusive of the duty. It is imagined that public brewers sometimes use this drug in the adulteration of ale and porter, for the purpose of rendering it more intoxicating than it otherwise would be.
It is employed for the destruction of vermin; and is said to be quickly fatal to dogs, foxes, wolves, and most other quadrupeds. When pounded and mixed with oatmeal, it is used for the killing of rats. Yet deleterious as this drug is, it has lately been employed on the Continent, as a medicine of great efficacy, in spasmodic affections of the bowels, and some other complaints; but its administration ought only to be attempted by medical men.
An extract of nux vomica has lately been imported from India; but it is not generally known for what purpose.
72. The TEAK-TREE (Tectonia grandis) is a valuable species of timber, which grows in the forests of the East Indies.