CRUDE DRUGS. 477 



cinnamic acid and rheosmin, an aldehyde having the odor of 

 rhubarb. A catechin resembhng the catechin of gambir has also 

 been found. Rhubarb also contains considerable starch ; calcium 

 oxalate; and yields about 15 per cent, of ash. 



Allied Plants. The rhizomes of other species of Rheum 

 are also used to a limited extent, as English or Austrian rhubarb 

 from Rheum rhaponticniii; they are more or less cylindrical, dis- 

 tinctly radiate, and contains, besides chrysophanic acid, rhapontin. 

 Rhcuni palmatinii which is cultivated in France. Germany and 

 Russia, produces rhizomes that are lighter in color and less valu- 

 able than the Chinese rhubarb, the constituents being similar to 

 those of Austrian rhubarb. 



ACONITUAL ACONITE. The tuberous root of Aconitmn 

 NapcUus (Fam. Ranunculaceae), a perennial herb (Figs. 84, 141), 

 growing in the mountainous districts of Europe, Asia and West- 

 ern North America. It is also cultivated in temperate regions 

 (p. 268). The commercial supplies are obtained from England 

 and Germany, and in England the root is collected in autumn 

 from cultivated plants after the overground parts have died down, 

 whereas in Germany the roots are collected from wild plants dur- 

 ing the flowering period, this being done to distinguish the partic- 

 ular species yielding the drug. The root should be carefully dried. 



Description. More or less conical or fusiform, 4 to 10 cm. 

 long, 5 to 20 mm. in diameter ; externally dark brown, smooth or 

 somewhat wrinkled, the upper portion with a bud, remains of 

 bud-scales or stem-scars, with numerous root-scars or short roots ; 

 fracture horny, somewhat mealy ; internally, bark light or dark 

 brown, i to 2 mm. thick, cambium irregular, 5- to 7-angled, wood 

 yellowish, in small bundles at the angles, pith light brown, about 

 2 to 6 mm. in diameter ; odor very slight ; taste sweetish, acrid, 

 pungent, accompanied by a sensation of numbness and tingling. 



The shrunken, hollow, older tubers, together with the over- 

 ground stem-remnants, should, be rejected. 



Inner Structure. See Figs 206, 309. 



Constituents. A number of alkaloids have been isolated, of 

 which aconitine is the most important ; it occurs to the extent 

 of about 0.75 per cent., and forms prisms (Fig. 142), which are 

 not colored by concentrated sulphuric or nitric acid. An aqueous 

 solution of the alkaloid, after acidulating with acetic acid, gives on 



