Flower-De-Luce, or Flag, Iris, L. a genus of plants consisting of 54 species, the following three of which are natives of Britain :

1. The pseudacorous, Water Flower-de-Luce, or Yellow Flag; which is perennial, grows on the banks of rivers, in marshes and wet meadows, and produces large yellow flowers in the month of July. The leaves of this plant, when fresh, are eaten by goats, and when in a dry state, by cows, but they are refused by horses and hogs. - On account of its poisonous nature to all cattle, except sheep, this vegetable ought to be carefully extirpated from meadow-grounds, and their contiguous ditches. The mice of the fresh root is very acrid, and has been found to produce plentiful evacuations from the bowels, after other powerful remedies had failed : by continuing its use, it cured an obstinate dropsy. For this purpose, it has been taken in closes of SO drops, every second or third hour; but the degree of its acrimony is so uncertain, that it can never be generally used.— With more advantage and safety we may recommend the whole of this strongly astringent plant to the tanner, and its flowers to the dyer, for extrating a beautiful yellow; but the root, in particular, as a substitute for galls in preparing a, black dye, or ink, with vitriol of iron. - Lastly, the roots of this species are stated to be an antidote to the bite of a mad-dog; and, after having been mixed with the food of some hogs that had been bitten, they escaped the disease, while others, injured by the same dog, died raving mad.

2. The fietida, STINKING Flower-de-Luce, Gladwyn, or Flag, which is found on hedge-banks, and sloping grounds, particularly in the south-western counties of England : it is perennial, and pro-duces flowers of a purplish ash-colour, which lose their smell during the night, and blow in the months of June and July. - This plant is refused by horses, sheep, and goats; its leaves are very fetid, and, when bruised, smell like rancid bacon. The juice of the roots of this, as well as the preceding species, have occasionally been used to excite sneezing; which is a dangerous practice, and has sometimes been attended with violent convulsions. It may, therefore, be more usefully employed for the de-struction of bugs and other vermin. 3. The Xiphium, or Bulbous-rooted Flower-de-Luce, or Flag, which has long been cultivated in our gardens, on account of its beauty. It has lately been found wild in the county of Wor-cester, and produces generally purplish-blue flowers. - M. Schulze informs us, in his "Social Narra-tives" (in German), that he made the following experiments with the azure-blue flowers of this negleted plant: He first bruised the Mower-leaves in a marble mortar, ex-pressed their juice, collected it in a shallow glass vessel, and, alter adding a small portion of finely-pulverized alum, he suffered it to dry under shade, in the open air: thus, he obtained a very beautiful green pigment. The flowers, however, should be gathered in dry weather, their white parts carefully separated from the coloured leaves, and the pounded alum gradually mixed With the juice, till the desired colour becomes perceptible. With this preparation, both linen and silk were dyed of a remarkably fine and permanent green colour. - Prof. Gmelin, in his German " Technical Chemistry" gives the following recipe for preparing a lively green water-colour: Take equal quantities of the expressed juice of the bulbous-rooted flag and rue, and add such a proportion of a strong solution of alum, as is required to produce the colour.