The genus Cornus is characterized by the following marks. Petals four, superior; involucrum of four leaves, or wanting; drupe with a two-celled nut. The species florida is arboreous, with its flowers in heads surrounded by an involucrum of obovate leaves with recurved points.

Class Tetandria, order Monogynia, natural or der Stellato, Lin. Caprifolia. Juss.

The Cornus florida is of slow growth, and possesses a very compact wood, covered with a rough, broken bark. The branches are smooth, covered with a reddish bark, marked with rings at the place of the former leaves. The leaves, which are small at the flowering time, are opposite, petioled, oval, acute, entire, nearly smooth, paler be

were about twelve feet high, spreading horizontally, their limbs, meeting and interlocking with each other, formed one vast, shady, cool grove, so dense and humid as to exclude the sun-beams, and prevent the intrusion of almost every other vegetable, affording us a most desirable shelter from the fervid sun-beams at noon day. This admirable grove has by way of eminence acquired the name of Dog woods.

During a progress of near seventy miles through this high forest, there constantly presented to view, on one hand or the other, spacious groves of this fine flowering tree, which must in the spring season, when covered with blossoms, present a most pleasing spectacle, when at the same time a variety of other sweet shrubs display their beauty; as the Halesia, Stewartia, Esculus, Azalea, &c. entangled with garlands of Bignonia, Glycine, Lonicera, &c. &c. at the same time the superb Magnolia grandiflora standing in front of the dark groves, towering far above the common level." Travels, p. 399.

neath, and marked, as in others of the genus, with strong parallel veins. The flowers, which are very small, grow in heads or sessile umbels, upon peduncles an inch or more in length. At the base of each bunch is the large spreading involu crum, constituting the chief beauty of the tree when in flower. This involucrum is composed of four white, nerved, obovate leaves, having their paint turned abruptly down or up, so as to give them an

obcordate appearance. This point has frequently

a reddish tinge. Calyx superior, somewhat bellshaped, ending in four obtuse spreading teeth. Petals four, oblong, obtuse, reflexed. Stamens four, erect, the anthers oblong with the filaments inserted in their middle. Style erect, shorter than the stamens, with an obtuse stigma. The fruit is an oval drupe of a glossy scarlet colour, containing a nucleus with two cells and two seeds.

The bark of the Cornus florida is a powerful bitter, possessing also an astringent and somewhat aromatic taste. Both tannin and the gallic acid are abundantly developed in its solutions by their proper tests. In my experiments with the bark of young twigs, but a small quantity of pure resin was made manifest. It would seem that the prin cipal seat of the bitterness is in a variety of extractive matter.

In a valuable inaugural dissertation on the Cornus florida and Cornus sericea by Dr. Walker of Virginia, much attention appears to have been bestowed on the chemical properties of their bark. He found that water distilled from the bark in powder had a transparent, whitish appearance, with a slight aromatic odour, and no perceptible taste. When the heat was increased, the fluid had a lemon colour, with an unpleasant smell and an acerb taste. These effects were probably produced by the volatilization and partial decomposition of portions of the bark in consequence of the heat being continued until the mixture was evaporated nearly to dryness.

With a view to ascertain the effect of different menstrua, Dr. Walker subjected to experiment the residual mass furnished by evaporating a decoction of the root of Cornus florida. Two drachms of this residuum, which had been furnished by seven and an half ounces of the decoction, were macerated in successive quantities of the best alcohol, until the last portion ceased to be changed in colour and taste. The part, which remained undissolved, weighed only half a drachm. When redissolved it was destitute of taste, and underwent no change of colour on adding the test of iron. The alcohol, which had been employed in the ex

periment, was found to possess an intensely bitter taste with astringency, of a clear red colour, and turning to a deep black on the addition of iron. On evaporation, it yielded a drachm and an half of residuum.—Dr. Walker attempted to ascertain the quantity of resin by macerating the alcoholic extract in repeated portions of sulphuric ether. The ether acquired a dark colour and a bitter taste, and was found to have dissolved three quarters of the extract. When tested with iron, it was found that the remaining quarter only was chang ed to a black colour.

The Cornus florida is one of the many vege tables which, by the union of their gallic acid with the salts of iron, form a black compound, applicable to the purposes of ink. The constancy of the black colour thus produced varies greatly, according to the substance from which the gallic acid is derived. It is often extremely fugacious, sometimes fading in a few days, and at others becoming indistinct after some weeks or months. Considering the very great importance of the pur poses for which ink is employed, and the immense evils which may result from its obliteration in writ ings intended for permanency; it is with extreme caution that we should recommend the introduction of any change in the mode of its formation. The

oak gall has had the experience of ages in favour of its permanence and immutability. It is not until some indigenous article, producing an equal intensity of colour, has undergone a series of trials from time and exposure, sufficient to establish beyond a doubt its durability, that its substitution in the manufacture of ink should be considered expedient or even justifiable.

Upon the human body the bark of the Cornus florida acts as a tonic, an astringent and an antiseptic, approaching in its general effects to the character of the Peruvian bark. From a variety of experiments made by Dr. Walker upon the healthy system, it was found that this medicine uniformly increased the force and frequency of the pulse, and augmented the heat of the body. Collateral experiments were made at the same time with the Peruvian bark, with which the Cornus appeared to agree both in its internal and external effects.

In disease it has been principally employed in the same cases for which the cinchona is resorted to, particularly intermittent and remittent fever. Dr. Gregg of Pennsylvania, cited by Dr. Walker, states, that after employing the Cornus florida habitually for twenty three years in the treatment of intermittents, he was satisfied that it was not in