COMFREY 349 



are occasionally substituted for the root of Alkanna tinctoria, the Syrian 

 drug being apparently more than half as rich again in colouring matter 

 as the Hungarian. Both of these substitutes are larger than alkanet 

 root. 



COMFREY ROOT 

 (Symphyti Radix ; Consolidae Radix) 



Source, &C. Comfrey root is the dried rhizome and root of 

 Symphytum officinale, Linne (N.O. Boraginew), an indigenous and 

 widely distributed perennial herb. The plant produces a large erect, 

 branching rhizome and stout, fleshy roots. 



Description. The commercial drug consists chiefly of root and 

 occurs in pieces of varying length (often 5 to 20 mm.) and about 5 

 to 15 mm. thick. Externally it is deeply longitudinally wrinkled 

 and blackish or greyish black ; internally it is pale grey, brownish, 

 or even brown in colour. It may be hard, horny or tough in con- 

 sistence and exhibits a waxy surface when cut. The structure is 

 often indistinct, but favourable pieces show a dark cork and a grey 

 cortex separated by a greyish cambium line from an indistinctly 

 radiate wood within which, in pieces of the rhizome, there is a circular 

 pith. It has a slight odour and a mucilaginous taste. 



Constituents. Comfrey root contains about 0-8 per cent, of allantoin 

 together with tannin, resin, gum, and sugar. 



Allantoin, C 4 H 6 O 3 N 4 , is a diureide of glyoxylic acid. It occurs in colourless, 

 glistening prisms melting at 227. Oxidising agents convert it into allantoic 

 acid, C 3 H 4 N 4 O 2 . It is soluble in solution of sodium hydroxide, the solution 

 evolving ammonia when heated, with simultaneous production of urea. 



Uses. The drug has been used as an application to wounds, sores 

 and ulcers, the healing action being attributed to the allantoin con- 

 tained in it. 



SCAMMONY ROOT 



(Radix Scammoniae) 



Source, &C. Scammony root is obtained from Convolvulus 

 Scammonia Linne (N.O. Convolvulacece), a twining plant indigenous 

 to the eastern Mediterranean countries, and resembling the common 

 bindweed but much larger. It produces a root, often of very consider- 

 able size, from which a number of slender aerial stems spring. The 

 root, which yields by incision the gum-resin scammony, is collected 

 and dried. It is exported from Odessa, Batoum, &c. 



Description. Scammony root is usually simple and often of large 

 size. Small roots measure about 12 mm. in diameter and 15 to 30 cm. 



