LECT. V.] THE ROOT. SOILS. 239 



Arnica,, Arnica montana ; and as expectorants, Se- 

 neka-root, Polygala senega, and the bulb of the 

 Squill, Scilla maritima. That division also of the 

 class of stimulants, which comprehends those re- 

 medies that exert a general operation on the sys- 

 tem, is equally rich in roots : thus, among the 

 permanent stimuli we find the roots of Common 

 Avens, Geum urbanum, Bistort, Polygonum Bis- 

 tort a, Tormentil, Tormentilla erect a, and of the 

 Water Dock, Rumex aquaticus, employed as astrin- 

 gents ; and those of Sweet Flag, Acorus Calamus, 

 Ginger, Zingiber officinale, Sweet Fennel, Anethum 

 Fceniculum, garden Angelica, Angelica archange- 

 lica, Zedoary, Curcuma Zedoaria, Yellow Gentian, 

 Gentiana lutea, Elecampane, Inula r Helenium, and 

 Calumba, as aromatics and tonics. Among the 

 diffusible stimuli the root of Thorn Apple, Datura 

 stramonium, is narcotic, and that of Valerian, Va- 

 leriana officinalis, antispasmodic ; whilst the bulb 

 of Meadow Saffron, Colchicum autumnale, besides 

 acting as a cathartic, exerts a directly sedative 

 effect on the nervous energy. 



As agents in the art of dying, the chief colour 

 that roots impart is red; in producing which, 

 those of Madder, Rubia tinctorum, and of Alka- 

 net, Anchusa tinctoria, are of great importance: 

 various shades of this colour are also obtained 

 from the roots of several species of Bed-straw, 

 Galium ; and a very beautiful, but less permanent 



