RHUBARB. 



precipitation, or alter the properties of this infufion, and 

 are therefore incompatible in formulae with it : viz. the 

 ftrong acids and lime-water, folution of fulphate of iron, 

 fulphate of zinc, nitrate of filvrr, oxymuriate of mercury, 

 fuperacetate of lead, and tartarized antimony ; infufions of 

 catechu, cinchona, and cufparia. 



Thefe infufions are the beft form in which rhubarb can 

 be given, when they are intended for acting on the bowels. 

 The dofe of the former may be from fjj to f * iv, and of 

 the latter half the quantity, united with neutral falts or aro- 

 matics, as circumftances may direft. 



Extra&um rhei, Lond. Pharm., extract of rhubarb, is 

 obtained by macerating for four days, in a gentle heat, a 

 pound of bruifed rhubarb root, with a pint of proof fpirit, 

 and feven pints of water ; then (training the folution, and 

 fetting it apart that the fcculencies may fubfide. Pour off 

 the clear liquor, and evaporate it to a proper confidence. 

 The»virtues of rhubarb are impaired during this procefs of 

 infpifiation, and the fimple infufion is preferable. The dofe 

 is from grs. x to j(i, given in the form of pills, or difiblvcd 

 in peppermint water. 



TinSura rhei, Lond., tincture of rhubarb, is prepared by 

 macerating for fourteen days two ounces of rhubarb root 

 fliced, half an ounce of cardamom feeds bruifed, two 

 drachms of faffron, in two pints of proof fpirit, and filter- 

 ing. The Dublin pharmacopeia directs to take of rhubarb 

 root fliced, two ounces ; lefler cardamom feeds hulked and 

 bruifed, and liquorice bruifed, of each half an ounce ; faf- 

 fron, two drachms ; and proof fpirit, two pints : to digefl 

 for feven days, and then filter. 



Tinclure r ha palm ah, Edinb., tincture of rhubarb, is pre- 

 pared by digefting for feven days three ounces of rhubarb 

 root fliced, half an ounce of lefler cardamom feeds bruifed, 

 in two pounds and a half of proof fpirit, and filtering through 

 paper. 



Tinftura rhei eompofila, Lond., compound tincture of 

 rhubarb, is prepared by macerating for fourteen days two 

 ounces of rhubarb root fliced, half an ounce of liquorice 

 root bruifed, ginger root fliced, and faffron, of each two 

 drachms, in a pint of water, and twelve fluid ounces of proof 

 fpirit, and then filtering. 



TinSura rhei el aloes, tincture of rhubarb and aloes, for- 

 merly elixir Jiicrum, or (acred elixir, Edinb., is prepared by 

 digelting for feven days ten drachms of rhubarb root fliced, 

 fix drachms of foecotonne aloes powdered, half an ounce of 

 leffer cardamom feeds bruifed, in two pounds and a half of 

 proof fpirit, and filtering through paper. 



Ti/itluia rhei et geniiante, tincture of rhubarb and gentian, 

 Edinb., formerly tinBura rhei amara, or bitter tincture of 

 rhubarb, is obtained by digelting for feven days two ounces 

 of rhubarb root fliced, half an ounce of gentian root fliced, 

 in two pounds and a half of proof fpirit, and filtering 

 through paper. 



All thefe tinctures of rhubarb are purgative and fto- 

 machic ; but they arc not generally ufed in the firft inten- 

 tion, on account of the (trength of the menitruum, and are 

 therefore more ufually employed as adjuncts to faline pur- 

 gatives, for giving them warmth, and to llomachic infufions 

 in dyfpepfia, flatulent colic, diarrhoea, the coilivenefs of 

 old people, and of cold phlegmatic habits. The dofe for 

 operating as a purgative is t 3 vj, and from f 3 j to fjhj 

 tor producing their ftomachic effects. 



Pilult rhei compofitt, Edinb., compound rhubarb pills. 

 See Pills. 



Vinum rhei palmati, Edinb., wine of rhubarb, is prepared 

 by macerating for fevcu days two ounces of rhubarb root 

 fliced, a drachm of canclla bark bruifed, in two ounces of 



proof fpirit, and fifteen ounces of Spanifh white wine, and 

 filtering through paper. This wine, when newly prepared, 

 has the fame properties, and may be applied to the fame 

 ufes, :;•; the tincture ; but it is liable to undergo decompofi- 

 tion. The dof? isfrom f jfi to f|j, or more. Rhubarb 

 is alio an ingredient in a variety of "compofitions. Woodr. 

 Med. Bot. Thornton's Lond.' Difp. 



The Indian rhubarb town 111 our gardens has this peculiar 

 property, that it yields a fine and clear gum. This is per- 

 fectly white and pellucid, and in the months of June and 

 July is fo plentiful, that an ounce may fometimes be gathered 

 at a time from one plant of it. It exudates of itfelf from 

 all parts of the (talks and ribs of the leaves, and fometimes 

 from the under part of the leaves themfelves. It flands in 

 fome places in large drops, and in others the (talks, &c. feem 

 only to be covered with a thin layer of it; and the under 

 part of the leaves in fome have it in form of twitted wires or 

 long icicles. The plant may always be feen wounded by a 

 fort of cauitic in the places where the germen makes its way 

 out, and thefe may be followed with any pointed initrument 

 through the fkin. In fome parts of the plant this juice is 

 found to be turned gummy within it, and looks like clear 

 ice. As this is the only known herbaceous plant that 

 yields a true gum like that of trees, it would be worthy of 

 obfervation, whether or not fome of our own plants have fome 

 tendency of nature to form a juice of the fame kind. It 

 would be moft proper to look for this in the plants of the 

 fame genus, and as nearly related to the rhubarb as we can. 

 The docks, fo common about our fields, are of the fame 

 genus ; and the forrel fhews, by its talte, that it is particu- 

 larly allied to the plant ; for both are alike of the dock kind, 

 and both alike four. It would be proper to look carefully 

 about the leaves of forrel a little before it flowers, to fee 

 whether any thing like the fame gum appears on it. 



There is yet this farther analogy between this rhubarb and 

 our common forrel ; that the hulks of our forrel, boiled in 

 water, with a little alum, turn it to a fine red colour ; and 

 the hulks of rhubarb do the fame, and both the one and the 

 other often turn red in decaying. 



The juice of the roots of this rhubarb, extracted by 

 bruiting and (teeping it in common water, when the liquor 

 is (trained and evaporated, becomes only a clear uninflam- 

 mable gum, and melts in the flame of a candle. This gum, 

 as well as that of the (talks and leaves, is of an inlipid 

 tafte ; and it is obfervable, that though the plant naturally 

 yields it in fo large a quantity, yet it will not flow from 

 wounds made by art in any part of the plant. Upon the 

 confideration of the inlipid talte of this gum, and its folu- 

 bility in water, we may found fome probable conjecture, in 

 regard to the different virtues of this plant in purging and 

 binding. 



The woody fibres have a (trong tafte ; and, in all proba- 

 bility, are alone endued with the allringent quality. An in- 

 fufion of rhubarb is laid to purge, and a powder of it to 

 bind : the reafon is ealily feen on this confideration. The 

 water in infufion takes up all this gummy juice, and its 

 other juices, but leaves the fibrofe part behind, in confe- 

 quence of which, it ought to purge without binding ; but 

 in cafe of giving the powder, the juices are in great part 

 evaporated in the drying, and the woody part left almoft 

 alone ; it therefore purges but little, and proves powerfully 

 aftringent. Phil. Traiif. N° 224. 



R.HUBARB, in Sigrieu/ftin; a plant of the thick, flefhy, 

 tap-rooted, perennial kind, that may 111 iome cafes be pro- 

 bably cultivated in the field with advantage. There are two 

 forts, the common, and the palmaledox true kind. In the lirll 

 the root llrikes to a great depth, and is thick and branching, 



h.iving 



