Madder, or Rubia, L. a genus of plants, comprising nine species, one of which is a natives of Britain, viz. the R. tinctorum, Wild, or Common Dyers-Madder. It is perennial, and flowers in the months of June and July.

The most proper soil for the cultivation of Madder, in this country, is a soft sandy loam, that has been in a state of tillage for several years, and which is at least 2 1/2 or 3 feet deep, being perfectly clear from all weeds. It is necessary to plough the land thoroughly, before the commencement of winter, during which it should be laid in ridges, in order to mellow; and early in the ensuing spring, this valuable plant is propagated from slips, carefully taken from the old roots : these slips ought, according to the late celebrated Miller, to be set by the dibble, in rows at the distance of two or three feet from each other; though, in the opinion of Bechstein, they should be planted only six inches asunder. And, as madder requires constant moisture, without which the young roots would shrivel and decay, it will be useful, before they are committed to the ground, to immerse them in a fluid paste made of the best garden mould and soft water. Besides, this transplantation should be undertaken only in rainy weather, or when there is reason to suppose that showers will speedily follow.

During the first summer, it will be sufficient to scuffle the plants with the Dutch hoe, as soon as the weeds appear : in the succeeding autumn, when the stalks or haulm begin to decay, they must be raked off the ground, and the intermediate spaces carefully dug with a spade, or turned up with a hoe-plough, the soil being laid over the roots or heads of the plants in a roundish ridge. In the ensuing summer, the same management must be repeated ; but, before the ground between the plants is hoed, the haulm must be laid over the next intermediate space for two or three weeks, at the expiration of which it should be turned hack again on those intervals which. have been hoed ; care being taken to scuffle the soil, so that all weeds may be eradicated. In the following autumn, the haulm must be cleared, and the mould thrown up in ridges, similar to those of the first year.

Early in the third spring, before the young sprouts appear, the ground should be well raked; and, as soon as they are ready to be removed, they must be carefully taken off, at a distance from the crown of the parent plant. The culture of madder, during this summer, varies little from that of the two preceding, the plant only being earthed up somewhat higher ; as it has now acquired more strength. As soon as the haulm begins to decay in autumn, the roots must be taken up, carefully dried under an airy shed ; whence they should be conveyed as speedily as possible to a kiln; and managed in a manner similar to that followed with malt or hops ; because the beauty of the colour greatly depends on the expedition with which it is prepared. From the kiln, the madder is conveyed to the pounding-house, where it is pulverized; in which state it is fit for use.

Madder is employed in considerable quantities for dyeing a fine red colour, and likewise as a first tint for several other shades :—if wool be previously boiled in a solution of alum and tartar, and then immersed in a hot decoction of tartar only with this drug, it will acquire a very durable, though not beautiful red tinge.

M. Margraaff obtained from madder a permanent lake of a fine red colour, which is applicable to every purpose of painting. He directs two ounces of the purest alum to be dissolved in three quarts of distilled water previously boiled in a clean glazed vessel, which is to be set over the; fire. As soon as .the solution begins to simmer, it ought to be withdrawn, and two ounces of the best Dutch madder added ; alter which the mixture is to be boiled once or twice, removed from the fire, and filtred through clean white paper. The liquor, thus strained, is now suffered to subside for a night; when the clear fluid must be poured into the glazed pot, heated over the fire, and a strained solution of salt of tartar gradually introduced, till the mader be wholly precipitated.— This mixture is next to be filtered, and boiling distilled water poured on the red powder, till the fluid no longer acquires a saline taste. It now remains only to dry the lake, which will be of a deep red colour: but, if two parts of madder be used to one of alum, the shade will be still deeper; and, if one part of the latter article be added to four of the former, it will produce a beautiful rose-co-lour.r—See also Red,

The root of the Common or Wild Madder, is an excellent detergent and aperient; on which account it has been highly recom-. mended in visceral obstructions, particularly of the uterus ; in coagulations of the blood, induced either by falls or bruises; in the beginning of dropsical complaints ; and especially in the rickets.—It may be given pulverized, in doses from 5 to 15 grains to children, and from half to a whole dram, three or four times a day, to adults. When taken internally, it possesses the remarkable property of tinging the urine with a deep red colour; and produces similar effects on the bones of animals, if eaten among oilier food.

Madder-roots pay, on importation a duty of :5s. 1 1/2d. per cwt. and are subject to a convoy-duty of 2s. 3d. per cwt. The same duty is paid for the drug imported in a manufactured state.

This root forms an .important article for dyeing ; and, in order to encourage its cultivation, the 31st Geo 11. c. 35, subjects persons convicted of stealing or destroying madder-roots, to make satisfaction for damages, at the discretion of the magistrate, for the first offence; or, in case of non-payment, the convict is liable to be committed to the house of correction for one month, or to be whipped ; for the second trespass, such offender is to be confined in the house of correction for three months; provided the prosecution be commenced within thirty days. - Those who wish to acquire a more intimate knowledge of the culture, etc. of this profitable drug, will be gratified by the perusal of Mr. Mil-lee's " Method of cultivating Madder," etc. (4to. 1758, 2s. 6d'.) in which the subject is clearly treated, and illustrated with plates.