a thin ferosus humor, occasionally oozing out of the glands about the mouth and throat.

Rhubarb: A genus of the monogyne order, belonging to the enneandra clasps of plants; and in the natural method ranking under the 12th order, Holoraceae. There is no calyx; the corolla is sixfold and persistent; and there is one triquetrous seed. There are five species, viz. 1. The rhaponticum, or common rhubarb, hath a large, thick, fleshy, branching, deeply-flaking root, yellowish within; crowned by very large, roundish, heart-shaped smooth leaves, on thick, slightly-furrowed foot-stalks; and an upright strong stem, two or three feet high, adorned with leaves singly, and terminated by thick close spikes of white flowers. It grows in Thrace and Scythia, but has been long in the English gardens. Its root affords a gentle purge. It is however of inferior quality to some of the following sorts; but the plant being attringing, its young stalks in spring, being cut and peeled, are used for tarts. 2. The palmatum, palmated-leaved true Chinese rhubarb, hath a thick fleshy root, yellow within; crowned with very large palmated leaves, being deeply divided into acuminate segments, expanded like an open hand; upright stems, five or fix feet high or more, terminated by large spikes of flowers. This is now proved to be the true foreign rhubarb, the purgative quality of which is well known. 3. The compactum, or Tartarian rhubarb, hath a large, fleshy, branched root, yellow within; crowned by very large, heart-shaped somewhat lobated, sharply indented, smooth leaves, and an upright large stem, five or six feet high, garnished with leaves singly, and branching above; having all the branches terminated by nodding panicles of white flowers. This has been supposed to be the true rhubarb; which, however, though of superior quality to some sorts, is accounted inferior to the rheum palmatum. 4. The undulatum, undulated, or waved-leaved Chinese rhubarb, hath a thick, branchy, deep-flaking root, yellow within; crowned with large, oblong, undulate, somewhat hairy leaves, having equal foot-stalks, and an upright firm stem, four feet high; garnished with leaves singly, and terminated by long loose spikes of white flowers. 5. The Arabian rhubarb, or currant rhubarb of Mount Libanus, hath a thick fleshy root, very broad leaves, full of granulated protuberances, and with equal foot-stalks, and upright firm stems, three or four feet high, terminated by spikes of flowers, succeeded by berry-like seeds, being surrounded by a purple pulp. All these plants are perennial in root, and the leaves and stalks are annual. The roots being thick, fleshy, generally divided, strike deep into the ground; of a brownish colour without and yellow within; the leaves rise in the spring, generally come up in a large head folded together, together, gradually expanding themselves, having thick foot-stalks; and grow from one to two feet high, or more, in length and breadth, spreading all round: amidst them rise the flower-items, which are garnished at each joint by one leaf, and are of strong and expeditious growth, attaining their full height in June, when they flower; and are succeeded by large triangular seeds, ripening in August. Some plants of each fort merit culture in gardens for variety; they will effect a singularity with their luxuriant foliage, spikes, and flowers; and as medical plants, they demand culture both for private and public use.

They are generally propagated by seeds sowed in autumn soon after they are ripe, or early in the spring, in any open bed of light deep earth; remarking, those intended for medical use should generally be sowed where they are to remain, that the roots, being not disturbed by removal, may grow large. Scatter the seeds thinly, either by broadcast all over the surface, and raked well in; or in shallow drills a foot and half distance, covering them near an inch deep. The plants will rise in the spring, but not flower till the second or third year: when they, however, are come up two or three inches high, thin them to eight or ten inches, and clear out all weeds; though those designed always to stand should afterwards be hoed out to a foot and a half or two feet distance: observing, if any are required for the pleasure ground, &c., for variety, they should be transplanted where they are to remain in autumn, when their leaves decay, or early in spring, before they shoot: the others remaining where sowed, must have the ground kept clean between them; and in autumn, when the leaves and stalks decay, cut them down, and slightly dig the ground between the rows of plants, repeating the same work every year. The roots remaining, they increase in size annually; and in the second or third year many of them will shoot up stalks, flower, and perfect seeds; and in three or four years the roots will be arrived to a large size; though older roots are generally preferable for medical use.

In Mr Bell's Travels we have an account of some curious particulars relating to the culture of rhubarb. He tells us, that the best rhubarb grows in that part of Eastern Tartary called Mongalia, which now serves as a boundary between Russia and China. The marmots contribute greatly to the culture of the rhubarb. Wherever you see 10 or 20 plants growing, you are sure of finding several burrows under the shades of their broad-spreading leaves. Perhaps they may sometimes eat the leaves and roots of this plant; however, it is probable the manure they leave about the roots contributes not a little to its increase; and their eating up the earth, makes it shoot out young buds and multiply. This plant does not run, and spread itself, like docks and others of the same species; but grows in tufts, at uncertain distances, as if the seeds had been dropped with design. It appears that the Mongols never accounted it worth cultivating; but that the world is obliged to the marmots for the quantities scattered, at random, in many parts of this country: for whatever part of the ripe seed happens to be blown among the thick grass, can very seldom reach the ground, but must there wither and die; whereas, should it fall among the loose earth thrown up by the marmots, it immediately takes root, and produces a new plant.

After digging and gathering the rhubarb, the Mongols cut the large roots into small pieces, in order to make them dry more readily. In the middle of every piece they scoop a hole, through which a cord is drawn, in order to suspend them in any convenient place. They hang them for the most part about their tents, and sometimes on the horns of their sheep. This is a most pernicious custom, as it destroys some of the best part of the root: for all about the hole is rotten and useless; whereas, were people rightly informed how to dig and dry this plant, there would not be one pound of refuse in a hundred; which would save a great deal of trouble and expense, that much diminish the profits on this commodity. At present, the dealers in this article think these improvements not worthy of their attention, as their gains are more considerable on this than on any other branch of trade. Perhaps the government may hereafter think it proper to make some regulations with regard to this matter.

Two sorts of rhubarb are met with in the shops. The first is imported from Turkey and Russia, in roundish pieces freed from the bark, with a hole through the middle of each: they are externally of a yellowish colour, and on cutting appear variegated with lively reddish streaks. The other, which is less esteemed, comes immediately from the East Indies, in length pieces, harder, heavier, and more compact than the foregoing. The first sort, unless kept very dry, is apt to grow mouldy and worm-eaten; the second is less subject to these inconveniences. Some of the more industrious artists are said to fill up the worm-holes with certain mixtures, and to colour the outside of the damaged pieces with powder of the finer sorts of rhubarb, and sometimes with cheaper materials: this is often so nicely done, as effectually to impose upon the buyer, unless he very carefully examines each piece. The marks of good rhubarb are, that it be firm and solid, but not flinty; that it be easily pulverizable, and appear, when powdered, of a fine bright yellow colour; that, upon being chewed, it impart to the spittle a saffron tinge, without proving flimsy or mucilaginous in the mouth. Its taste is subacrid, bitterish, and somewhat astringent; the smell lightly aromatic.

Rhubarb is a mild cathartic, which operates without violence or irritation, and may be given with safety even to pregnant women and children. Besides its purgative quality, it is celebrated for an astringent one, by which it strengthens the tone of the stomach and intestines, and proves useful in diarrhoeas and disorders proceeding from a laxity of the fibres. Rhubarb in substance operates more powerfully as a cathartic than any of the preparations of it. Watery tinctures purge more than the spirituous ones; whilst the latter contain in greater perfection the aromatic, astringent, and corroborating virtues of the rhubarb. The dose, when intended as a purgative, is from a scruple to a dram or more.

The Turkey rhubarb is, among us, universally preferred to the East India sort, though this last is, for some purposes at least equal to the other; it is manifestly more astringent, but has somewhat less of an aromatic flavour. Tinctures drawn from both with rectified spirit have nearly the same taste: on distilling off the menstruum, the extract left from the tincture of the East India rhubarb proved considerably the strongest.

Rhubarb has been cultivated of late in this country with considerable success, and for medical purposes is found to equal that of foreign growth, as is proved by the Transactions of the London Society for encouraging Arts, Manufactures, and Commerce, who have rewarded several persons both for cultivating and curing it. In the Transactions for 1792, the gold medal was adjudged to Sir William Fordyce, for raising from seed in the year 1791 upwards of 300 plants of the true rhubarb, or rheum palmatum of the London Pharmacopoeia 1788, which in the second and third weeks of October were transplanted into a deep loam, at four feet distance from each other, according to rules laid down by the society. In 1793 it was adjudged to Mr Thomas Jones, from whose papers we derive the following information.

After giving an accurate account of his experiments and observations, he concludes, that the season for sowing is the spring about March or April, or in autumn about August and September; that those plants which are raised in the spring should be transplanted in autumn, and vice versa; that they cannot have too much room; that room and time are essentially necessary to their being large, of a good appearance, and perhaps to the increase of their purgative qualities; that to effect these purposes, the soil must be light, loamy, and rich, but not too much so, lest the roots should be too fibrous; that their situation can scarcely be too dry, as more evils are to be expected from a superabundance of moisture than any actual want of it; and lastly, we may conclude, that in particular the injuries which they are subject to are principally during their infancy, and to be imputed to insects and inattention to the planting season; afterwards, from too great an exposure to frost: but that none can be dreaded from heat; and that in general they are hardy and easy of cultivation, when arrived beyond a certain term.

The method of curing rhubarb, as proposed by Dr Tirrougel of Stockholm, is as follows: "No roots should be taken up till they have been planted ten years: they should be taken out of the ground either in winter, before the frost sets in, or in the beginning of spring, and immediately cut into pieces, and carefully barked; let them be spread upon a table for three or four days, and be frequently turned, that the juices may thicken or condense within the roots. After this process, make a hole in each piece, and put a thread through it; by which let them hang separately, either within doors, or in some sheltered shady shed. Some persons dry them in a different way: they inclose the roots in clay, and make a hole in the clay, about the thickness of a goose-quill, and in this manner hang up each piece to dry separately, that the moisture may not evaporate, nor the strength of the root be weakened. But the methods which the Tartars follow is a bad one: they dig the roots out of the deserts where they grow, bark them, and immediately string them, and hang them round the necks of their camels, that they may dry as they travel; but this greatly lessens the medicinal virtue of the root."

Mr Thomas Halley of Pontefract in Yorkshire, to whom the London Society voted the silver medal in 1793, informs us, that his father tried various experiments for curing rhubarb, as washing, brushing, baking, and peeling, and he dried them in the sun, on a kiln, in a stove, or in a warm kitchen. But of the success of all or either of these methods we have no account, owing to the death of Mr Halley's father. He sent, however, to them five different specimens, which the Society acknowledges to be superior to any rhubarb hitherto cured in England, and produced to them. The roots sent, Mr Halley says, were planted about the year 1781 in a light sandy soil, but were much neglected. They were taken up in the spring of 1792, and being thoroughly divested of the adhering earth, were placed for some weeks on the floor of a cool warehouse; the fibres were then taken off, cut up, and dried on the flue of a green-house; but, from mismanagement, were entirely spoiled. The prime roots were fevered in small pieces, peeled clean, and thoroughly cleared of every particle of unwholesome. Part was separately laid in sieves, and the remainder perforated, strung, and suspended in fettlers from the ceiling of a warm kitchen. The manner of dressing consists in paring off the external coat with a sharp knife, as thin and clean as possible, and then finishing it off by a piece of fish-skin, with its own powder; which powder may be procured from the chips and small pieces, either by grinding or pounding it in a large mortar.

In the year 1794 the Society adjudged the gold medal to Mr William Hayward of Hanbury, Oxfordshire, for propagating rhubarb by offsets taken from the crowns of large plants, instead of seeds, for the purpose of bringing it to perfection in a shorter time, which fully answered his expectations. Mr Hayward was a candidate in the year 1789 for the gold medal; but having misunderstood their rules, he was not entitled to it, though with great propriety they voted to him the silver medal; in consequence of which he sent them his method of culture and cure. His method of cultivating Turkey rhubarb from seed is thus explained to the Society: "I have usually sown the seed about the beginning of February, on a bed of good soil (if rather sandy the better), exposed to an east or west aspect, in preference to the south; observing a full sun to be prejudicial to the vegetation of the seeds, and to the plants whilst young. The seeds are best sown moderately thick (broad-cast), treading them regularly in, as is usual with parsnips and other light seeds, and then raking the ground smooth. I have sometimes, when the season has been wet, made a bed for sowing the rhubarb seeds upon, about two feet thick, with new dung from the stable, covering it near one foot thick with good soil. The intent of this bed is not for the sake of warmth, but solely to prevent the rising of earthworms, which, in a moist season, will frequently destroy the young crop. If the seed is good, the plants often rise too thick; if so, when they have attained six leaves they should be taken carefully up (where too close), leaving the standing crop eight or ten inches apart: those taken up may be planted at the same distance, in a fresh spot of ground, in order to furnish other plantations. When the plants in general are grown to the size that cabbage-plants are usually set out for a standing crop, they are best planted where they are to remain, in beds four feet wide, one row along the middle of the bed, leaving two yards distance betwixt the plants," plants, allowing an alley between the beds about a foot wide, for convenience of weeding the plants. In the autumn, when the decayed leaves are removed, if the shoveling of the alleys are thrown over the crowns of the plants, it will be found of service.

His mode of cultivating the same plant by offsets is thus given: "On taking up some plants the last spring, I slipped off several offsets from the heads of large plants; these I set with a dibble about a foot apart, in order, if I found them thrive, to remove them into other beds. On examining them in the autumn, I was surprised to see the progress they had made, and pleased to be able to furnish my beds with 40 plants in the most thriving state. Though this was my first experiment of its kind, I do not mean to arrogate the discovery to myself, having known it recently tried by others, but without being informed of their success. I have reason to think this valuable drug will, by this method, be brought much sooner to perfection than from seed."

His method of curing rhubarb is thus described: "The plants may be taken up either early in the spring, or in autumn, when the leaves are decayed, in dry weather if possible, when the roots are to be cleared from dirt (without washing); let them be cut into pieces, and with a sharp knife freed from the outer coat, and exposed to the sun and air for a few days, to render the outside a little dry. In order to accelerate the curing of the largest pieces, a hole may be scooped out with a penknife; these and the smaller parts are then to be strung on packthread, and hung up in a warm room (I have always had the convenience of such a one over a baker's oven), where it is to remain till perfectly dry. Each piece may be rendered more tightly by a common file, fixing it in a small vice during that operation; afterwards rub over it a very fine powder, which the small roots furnish in beautiful perfection, for this and every other purpose where rhubarb is required."

In the year 1794, too, the Society adjudged the gold medal to Mr. Ball for his method of curing the true rhubarb, which is as follows: "I take the roots up when I find the stalks withering or dying away, clean them from the earth with a dry brush, cut them in small pieces of about four or five inches in breadth, and about two in depth, taking away all the bark, and make a hole in the middle, and string them on packthread, keeping every piece apart; and every morning, if the weather is clear and fine, I place them in the open part of the garden, on stages, erected by fixing small posts about six feet high in the ground, and fix feet astern, into which I fix horizontal pegs, about a foot apart, beginning at the top; and the rhubarb being strung crosswise on small poles, I place them on these pegs; so that if it should rain, I could easily remove each pole with the suspended pieces, into any covered place. I never suffer them to be out at night, as the damps at this season would be apt to mould them; and if at any time I perceive the least mark of mould, I rub it off with a dry cloth. In some of the pieces of rhubarb which I have cured this year, I have made holes about half an inch diameter in the middle, for the free passage of air, and have found that every one of these pieces dried better than the others where no such holes were made; and have likewise hung several strings in the kitchen, and never exposed them in the open air, and found them to dry exceedingly well, and much better than those in the open air. Some years since I dried a quantity of rhubarb in a malt-kiln, keeping up the thermometer to 80 degrees, which answered well, but I think rather dried too quick: the roots which I have cured this year are a part of the plantation of 1789, and for which the Society was so kind as to give me a medal (a)."