RHUBARB. 



543 



Rand, at Chelsea, were said to supply this 

 important desideratum. 



As some doulits still remained, Boerhaave 

 procured from a Turkish merchant the seeds of 

 those plants whose roots he annually sold. These 

 seeds were soon propagated, and were discovered 

 to produce two distinct species, the r. undulatum, 

 and r. palmatum. Previous to this time Dr 

 Gorter had repeatedly sent its seeds to Linnseus, 

 hut the young plants which thej' produced con- 

 stantly perished; at length he obtained the fresh 

 root, which succeeded very well at Upsal, and 

 afterwards enabled the younger Linnseus to 

 describe this plant in 1767. 



Two years before this, Dr Hope had read 

 before the Royal Society of London, an account 

 of a plant of the r. palmatum, which grew in 

 the Botanic garden at Edinburgh. " From the 

 perfect similarity of this root," says Dr Hope, 

 " with the best foreign rhubarb, in taste, smell, 

 colour, and purgative qualities, we cannot doubt 

 of our being at last possessed of the plant which 

 produces the true rhubarb; and may reasonably 

 entertain the agreeable expectations of its prov- 

 ing a very important acquisition to Britain." 

 Since that period this species, as well as several 

 others, have been cultivated with success in this 

 country. But owing to the prejudice in favour 

 of foreign roots, the demand for the home growth 

 has not been such as to encourage its farther 

 cultivation. The only deficiency was in the 

 digging of the root, but this might easily be 

 improved. Its cultivation is easy. It is sown 

 in spring, in a light soil, and transplanted next 

 spring into a similar soil well trenched, the 

 plants being sftt at a yard distance from each 

 other each way. The third year some plants 

 begin to flower; but the roots are not lifted till 

 the autumn of the sixth year. When dug out 

 of the ground, they are first to be washed in a 

 large quantity of water; and after the fibres and 

 small roots are cut off, they are well brushed in 

 fresh water, and cut into pieces of a proper size. 

 The brown bark is then washed off, and they 

 are again thrown into fresh water for three or 

 four hours, in which they give out a great quan- 

 tity of gummy matter. They are then taken 

 out and laid upon twigs to drip till next morn- 

 ing; and it is chiefly in this time that they 

 exude at every part, a white, transparent, gummy 

 matter, resembling jelly. They are lastly placed 

 in a stove, heated to 120° or 140°, till they dry. 

 Twenty-five pounds of the recent root, yield 

 only about eight pounds of the dry. It is not, 

 however, yet fit for sale. All the wrinkles must 

 be rasped and filed out, and the pieces thus 

 dressed put in a barrel fixed on an axis, and 

 rolled about in it for twenty minutes or half an 

 hour, when they get covered by a fine powder 

 formed by their rubbing against each other. 

 Prepared in this way, it may be powdered, and 



has in every respect the appearance of foreign 

 rhubarb. The chief peculiarity in this process 

 is the steeping the roots in water, to extract the 

 gummy or mucilaginous matter; without this 

 precaution, according to Baume, the root cannot 

 be reduced to powder, even when perfectly dry, 

 but becomes pasty under the pistil. British 

 rhubarb is cultivated in considerable quantities 

 in the neighbourhood of Edinburgh, and sold 

 at nearly the price of foreign rhubarb. It is 

 easily reduced to a very fine powder, although 

 it is merely washed and peeled, before it be cut 

 into proper pieces, and dried upon the top of a 

 baker's oven. 



There are two sorts of rhubarb imported into 

 this country, Chinese and Turkey rhubarb, dif- 

 fering in quality, although they both come from 

 the same country. All the rhubarb of com- 

 merce is brought from the Chinese town, Sini, 

 or Selim, by the Bucharians. It grows on the 

 neighbouring chain of lofty mountains, which 

 stretches to the lake Kokonor, near the source 

 of the river Chorico. It is dug up by the pea- 

 sants, cleared from the earth, cut into pieces, 

 strung with the bark on strings, and exposed to 

 dry under cover in the shade for a whole year, 

 when it is again cleansed and prepared for expor- 

 tation. In Kiachta, on the Russian frontier, it 

 is received from the Bucharians by a Russian 

 apothecary, who examines it; the bad is imme- 

 diately burnt, and the good is freed from its 

 bark, woody parts, and every impurity in the 

 most careful manner. It is then sent to Moscow 

 and Petersburgh, where it undergoes a second 

 examination. This forms the Russian or Turkey 

 rhubarb, which is reckoned the best. It is com- 

 monly in round pieces, of a reddish or whitish- 

 yellow colour, feels gritty between the teeth; 

 and is often perforated with so large a hole, that 

 many pieces have the appearance of a mere 

 rind. The Chinese or East India rhubarb, is 

 brought by sea from Canton, and is heavier, 

 harder, and more compact, than the other; sel- 

 dom perforated with holes, and is either in long 

 pieces or with two flat sides, as if they had been 

 compressed. The general characters of good 

 rhubarb are, its having a whitish or clear yellow 

 colour, being dry, solid, and compact; moderately 

 heavy, brittle; where recently broken appearing 

 marked with yellow or 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, somewhat astringent 

 taste, and when chewed feeling gritty under the 

 teeth; speedily colouring the saliva, and not 

 appearing very mucilaginous. Rhubarb contains 

 a large proportion of bitter extractive matter, 

 soluble in water and spirits; and also an aromatic, 

 odorous matter, on which its activity as a pur- 

 gative depends. 



