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Show 412 RHUBARB. RHUBARB. This account may serve to show both the ardour of this respectableSociety in encouraging the growthof this useful article, and the persevering industry of some gentlemen in overcoming all the difficulties attendant on introducing a new plant into cultivation, finding out the means ofcuring it as an article for ex- tensive sale, and overcoming the prejudices of such as cannot persuade themselves that a drug of British growth can bear a competition with what is sent us from foreign countries. To conclude: The duke of Athol has raised rhubarb in Scotland which was thought by eminent druggists, and gentlemen of the medical profession in London, to be nearlyif not quite equal to the Russian, in smell, taste, and effect. By paying little more attention to the curing, they conceived that its beauty might be increased ; upon which, the year after, his grace sent up specimens ofstill superior quality. It having braved the climate of St. Petersburgh, and succeeded well in Scotland, is a sufficient proof of its hardiness. Dr. Robertson informs us, that it grows luxuriantly in Perthshire (latitude 56°); that gardeners and othersraise it there in great perfection ; and that there is in Scotland a constant demand for it as a medicine. The general characters of good rhubarb are, its having a whitish or clear yellow colour, being dry, solid, and compact, moderately heavy; brittle;’ when recently broken appearing marked with yellowor reddish veins, mixed with white; being easily pulverizable ; forming a powder of a fine bright yellow, having the peculiar, nauseous, aromatic smell of rhubarb, and a subacrid, bitterish, somewhatastringent taste, and when chewed feeling gritty under the teeth, speedily colou ring the saliva, and not appearing very mucilaginous. The size and form of the pieces areof little consequence; only we must break the large ones, to see that they are not decayed or rotten within; and we must also observe that they are not musty or worm-eaten. This is the more necessary, as damaged pieces are frequently so artfully dressed up, and coloured with powdered rhubarb, as to impose on the buyer. The principal constituent of rhubarbis extractive matter, sojuble both in alcohol and in water. Bygentle decoction it loses above one-half its weight. Rhubarb also contains some volatile odorous matter, on which its peculiar nauseous smell, and its activity as a purge, depend; for when dissipated, either by age 413 or any preparation to which the rhubarb has been subjected, the powers of the medicine are almost destroyed. It also contains about one-sixth of its weight of oxalate of lime, and some tan. nin, which resides entirely in the dark-coloured veins ; for, on wetting the surface with a weak chalybeate solution, these alone are blackened, while the white veins do not change their colour. Neumann got from 480grains 180 of alcoholic, and afterwards 170 watery extract ; and inversely, 350 watery, and only 5 of alcoholic extract. MEDICAL USE. Rhubarbis a mild cathartic, which operates without violence or irritation, and may be given with safety even to pregnant women and to children. In some people, however, it occasions severe griping. Besides its purgative quality it is celebrated as anastringent, by which it increases the tone of the stomach and intestines, and proves useful in diarrhcea and disorders proceeding from laxity. Rhubarbis exhibited, 1. In substance, in the form of powder. It Operates more powerfully as a purgative in this form than in any other. The dose for an adult is about a scraple or upwards. On account of its great bulk it is sometimes unpleasant to take a sufficient dose; its laxative effects are therefore often increased by the ad. dition of neutral salts, or other more active purgatives. In smaller doses it often proves an excellent stomachic. 2. In infusion. Rhubarb yields more of its purgative property to water than to alcohol. Theinfusion is, however, considerably weaker than the powder, and requires double the dose to produce the same effect. It is well adapted for children, but must be always fresh prepared. 3. In tincture. On account of the stimulating nature of the menstruum, this preparation frequently cannot be exhibited in doses large enough to operate as a purgative. Its principal use is as a tonic and stomachic. The virtues of rhubarb are destroyed by roasting, boiling, and in forming the extract. PREPARATIONS, Inruston or Ruusars. (Infusum Rhei Palmati. E.) Take of rhubarb, bruised, half an ounce ; - boiling water, eight ounces; ———. spirit of cinnamon, one ounce: |