ay also be stained of a durable purple by means of solution of gold in aqua regia. The solution for this purpose should be as fully saturated as possible; it should be diluted with three times its quantity of water; and if the colour is required deep, the piece, when dry, must be repeatedly moistened with it. The colour does not take place till a considerable time, sometimes several days, after the liquor has been applied; to hasten its appearance, the subject should be exposed to the sun and free air, and occasionally removed to a moist place, or moistened with water.—When solution of gold in aqua regia is soaked up in linen cloths, the metal may be recovered by drying and burning them. The anacardium nut, which comes from the East-Indies, is remarkable for its property of staining linen of a deep black colour, which cannot be washed out either with soap or alkaline ley. The stain is at first of a reddish-brown, but afterwards turns to a deep black on exposure to the air. The cashew-nut, called the anacardium of the West-Indies, differs from the oriental anacardium, in its colouring quality. The juice of this nut is much paler than the other, and stains linen or cotton only of a brownish colour; which indeed is very durable, but does not at all change towards blackness.—There are, however, trees, natives of our own colonies, which appear to contain juices of the same nature with those of India. Of this kind are several, and perhaps the greater number, of the species of the toxicodendron or poison-tree. Mr. Cateby, in his history of Carolina, describes one called there the poison-ash, from whose trunk flows a liquid as black as ink, and supposed to be poisonous; which reputed poisonous quality has hitherto prevented the inhabitants from collecting or attempting to make any use of it. In the Philosophical Transactions for the year 1755, the abbe Mazeas gives an account of three sorts of the toxicodendron raised in a botanic garden in France, containing in their leaves a milky juice, which in drying became quite black, and communicated the same colour to the linen on which it was dropped. The linen thus stained was boiled with soap, and came out without the least diminution of colour; nor did a strong ley of wood-ashes make any change in it. Several of these trees have been planted in the open ground in England, and some still remain in the bishop of London's garden at Fulham.

That species called by Mr Miller the true lac tree, was found by Dr Lewis to have properties of a similar kind. It contains in its bark, and the pedicles and ribs of the leaves, a juice somewhat milky, which soon changed in the air to a reddish-brown, and in two or three hours to a deep blackish or brownish-black colour: wherever the bark was cut or wounded, the incision became blackish; and on several parts of the leaves the juice had spontaneously exuded, and stained them of the same colour. This juice, dropped on linen, gave at first little or no colour, looking only like a spot of oil; but, by degrees, the part moistened with it darkened in the same manner as the juice itself. On washing and boiling the linen with soap, the stain not only was not discharged, but seemed to have its blackness rather improved; as if a brown matter, with which the black was manifestly debased, had been in part washed out, and left the black more pure.

As the milky juices of some of our common plants turn dark-coloured or blackish in drying, the doctor was induced to try the effects of several of them on linen. The milks of wild-poppies, garden-poppies, dandelion, hawk-weed, and sow-thistle, gave brown or brownish-red stains, which were discharged by washing with soap; the milks of the fig-tree, of lettuces, and of different kinds of spurge, gave no colour at all. The colourless juice which issues from hop-balls when cut, stains linen of a pale-reddish or brownish-red, extremely durable; the colour was deepened by repeated applications of the juice, but it never made any approach to blackness. The juice of floes gave likewise a pale-brownish stain, which, by repeated washings with soap, and being wetted with strong solution of alkaline salt, was darkened to a deeper brown: on baking the floes, their juice turns red; and the red stain which it then imparts to linen is, on washing with soap, changed to a pale-blueish, which also proves durable. These colours could not be deepened by repeated applications of the juice. The floes were tried in different states of maturity, from the beginning of September to the middle of December, and the event was always nearly the same.

In the fifth volume of Linnæus's Amoenitates Academicae, mention is made of a black colour obtained from two plants which grow spontaneously in Britain; the one is the altar spicata, herb-christopher, or baneberries; the other the enica baccafera nigra, black-berried heath, crow-berries, or crake-berries. The juice of the bane-berries boiled with alum, is said to yield a black ink; and the heath-berries, boiled also with alum, to dye linen of a purplish black.

Linens flowered with Gold leaf. Dr Lewis informs us of a new manufacture established in London for embellishing linen with flowers and ornaments of gold-leaf. The linen, he says, looks whiter than most of the printed linens; the gold is extremely beautiful, and bears washing well. The doctor informs us, that he had seen a piece which he was credibly informed had been washed three or four times, with only the same precautions which are used for the finer printed linens; and on which the gold continued entire, and of great beauty.—Concerning the process used in this manufacture, he gives us no particulars.

Festive Linen, is a kind of amianthus, which consists of flexible, parallel, soft fibres, and which has been celebrated for the uses to which it has been applied, of being woven, and forming an incombustible cloth. Paper also, and wicks for lamps, have been made of it. See Amianthus and Asbestos.