352.  Hypericum perforatum.  St. John’s wort.  The Leaves and Flowers.—­Its taste is rough and bitterish; the smell disagreeable.  Hypericum has long been celebrated as a corroborant, diuretic, and vulnerary; but more particularly in hysterical and maniacal disorders:  it has been reckoned of such efficacy in these last, as to have thence received the name of fuga daemonum.

353.  JASMINUM officinale.  Jasmine.  The Flowers.—­The flowers have a strong smell, which is liked by most people, though to some disagreeable:  expressed oils extract their fragrance by infusion; and water elevates somewhat of it in distillation, but scarcely any essential oil can be obtained from them:  the distilled water, kept for a little time, loses its odour.

354.  Iris Pseudoacorus.  Flower-de-Luce.  The Root.—­The roots, when recent, have a bitter, acrid, nauseous taste, and taken into the stomach prove strongly cathartic; and hence the juice is recommended in dropsies, in the dose of three or four scruples.  By drying they lose this quality, yet still retain a somewhat pungent, bitterish taste:  their smell in this state is of the aromatic kind.

355.  Iris florentina.  Florentine iris, or Orris-root.—­The roots grown in this country have neither the odour nor the other qualities that those possess which are grown in warmer climates:  so that, for the purposes of medicine, they are usually imported from Leghorn.

The root in its recent state is extremely acrid, and, when chewed, excites a pungent heat in the mouth which continues several hours; but on being dried, this acrimony is almost wholly dissipated, the taste becomes slightly bitter, and the smell approaching to that of violets.  It is now chiefly used in its dried state, and ranked as a pectoral or expectorant.  The principal use of the roots is, however, for the purposes of perfumery, for which it is in considerable demand.

356.  Lactuca sativa.  Garden lettuce.  The Leaves and Seeds.—­It smells strongly of opium, and resembles it in its effects; and its narcotic power, like that of the poppy heads, resides in its milky juice.  An extract from the expressed juice is recommended in small doses in dropsy.  In those diseases of long standing proceeding from visceral obstructions, it has been given to the extent of half an ounce a-day.  It is said to agree with the stomach, to quench thirst, to be greatly laxative, powerfully diuretic, and somewhat diaphoretic.

357.  Lamium album.  White Archangel, or dead Nettle.  The Flowers.—­The flowers have been particularly celebrated in female weaknesses, as also in disorders of the lungs; but they appear to be of very weak powers.

358.  LAVENDULA Stoechas.  Arabian Stoechas, or French Laven-der.  The Flowers.—­They have a very fragrant smell, and a warm, aromatic, bitterish, subacrid taste:  distilled with water, they yield a considerable quantity of a fragrant essential oil; to rectified spirit it imparts a strong tincture, which inspissated proves an elegant aromatic extract, but is seldom used in medicine.