106 MEDICINAL PLANTS. 



ly, this ought to be no objection to its use. Respecting the choice 

 of the different kinds of aloes, it may be observed that the socoto* 

 rine, as already mentioned, contains more gummy matter than the 

 hepatic, and hence is found to purge with more certainty and greater 

 irritation ; therefore is most proper where a stimulus is required, 

 or for promoting the uterine discharge ; while the hepatic is better 

 calculated for the purpose of a common purgative j and also by 

 containing more resin answers better for external application consi- 

 dered as a vulnerary. 



A full description of this plant is given in Dr. Edward Smith's 

 edition of Sibthorp's superb Flora Grseca. Sibthorp asserts, that the 

 aloe vulgaris, or common Barbadoes aloes, is the true AAcfyofDios- 

 corides, and in every respect resembles the Barbadoes aloes as de- 

 scribed by Sloane in his History of Jamaica. 



\Dioscor. Sloane. Woodv. Powell. 



SECTION XXI. 



Rhubarb. 



Jtheum Palmatum. Wildest. 



The rheum or rhubarb genus has eight species, as follows, all of 

 which are actively or slightly aperient. 



1. R.rhapontieum. Common rhubarb, a native of Thrace. 



2. R. palmatum. Palmate-leaved, or true Chinese rhubarb. 



3. R. undulatum. Wave leaved Chinese rhubarb. 



4. R. compactum. Thick leaved or compact rhubarb, a native 

 of Tartary. 



5. R. ribes. Wasted-leaved Persian rhubarb. 



fj. R.Tartaricum. Tartarian or heart-leaved rhubarb. 



7. R. hybridum. Hybrid rhubarb, a native of Asia. 



8. R. leucorrhizum. A native of Siberia. 



The officinal rhubarb is the species named in the second of these . 

 The root is perennial, thick, of an oval shape, and sends off long 

 tapering branches ; externally it is brown, and internally of a deep 

 yellow colour : the stalk is erect, round, hollow, jointed, sheathed, 

 slightly scored, branched towards the top, and rises to the height of 

 six or eight feet : the radical leaves are numerous, large, rough, of 

 a roundish figure, and deeply cut into lobes, and irregularly pointed 





