RHUBARB. 199 



first is in oblong pieces, flattish on one side, and convex on the 

 other ; compact, hard, heavy, internally of a dull red colour, varie- 

 gated with yellow and white, and when recently powdered appears 

 yellow, but on being kept becomes gradually redder. The second 

 is the most valuable, and is brought to us in roundish pieces, with a 

 large hole through the middle of each ; it is more soft and friable 

 than the former sort, and exhibits, when broken, many streaks of a 

 bright red colour. " The marks of the goodness of rhubarb are, 

 the liveliness of its colour when cut ; its being firm and solid, but 

 not flinty or hard ; its being easily pulverable, and appearing when 

 powdered of a fine bright yellow colour ; its imparting to the spittle, 

 when chewed, a deep saffron tinge, and not proving slimy or muci- 

 laginous in the mouth ; its taste is subacrid, bitterish, and somewhat 

 styptic ; the smell lightly aromatic." 



The purgative qualities of rhubarb are extracted more perfectly 

 by water than by rectified spirit : the root remaining after the action 

 of water is almost if not wholly inactive; whereas after repeated 

 digestion in spirit, it proves still very considerably purgative. The 

 virtue of the watery infusion, on being inspissated by a gentle heat, 

 is so much diminished, that a dram of the extract is said to have 

 scarcely any greater effect than a scruple of the root in substance ; 

 the spirituous tincture loses less; half a dram of this extract proving 

 moderately purgative. " The qualities of this root are that of a 

 gentle purgative, and so gentle, that it is often inconvenient by rea- 

 son of the bulk of the dose required, which in adults must be from 

 half a dram to a dram. When given in a large dose, it will occa- 

 sion some griping, as other purgatives do; but it is hardly ever 

 heating to the system, or shews the other effects of the more drastic 



long chain of mountains in Tartary, -which extend from Selin to the lake Koko- 

 nor near Tibet. At a proper age the roots are taken up, which, according to 

 Pallas, is in April or May ; but in Bell's account, this is said to be done in the 

 autumn: they are then to be cleaned, the smaller branches cut off, and the 

 larger roots divided into pieces of a proper size ; after this they are perforated 

 and suspended to dry either upon the neighbouring trees, or in tents, or as some 

 have reported, to the horns of sheep. The proper exsiccation of this root is 

 certainly attended with considerable difficulty, and the cultivators of rhubarb 

 in this country have not yet agreed in what mode this is to be best accom- 

 plished. The recent root in this process, according to the experiment of Sir 

 William Fordyce, loses nearly nine-tenths of its weight," See Tram, of the 

 Society for Encouragement of Arti, Ac, 



O 4 



