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92 ARISTOLOCHIACE^. 



or Colubriua, i.e. snake-root, to the rhizome of Polygomim Bistorta, L. 

 In America it was not the appearance, but the application of the drvar 

 under notice to which it owes the name snake-root. 



The earliest account of Virginian snake-root is that of Thomas 

 Johnson, an apothecary of London who published an edition of Gerarcle's 

 Herbal in 163C. It is evident however that Johnson confounded a 

 species of Arisfolochia from Crete with what he calls *' that snake-weed 

 that was brought from Virginia and grew with Mr. John Tradescant 

 at South Lambeth, anno 1632," It was very briefly noticed by 

 Cornuti in his Canadenshim Plcmtarum Ilistoria (1635); and in a 

 much more intelligent manner b}^ Parkinson in 1640, These authors, 

 as well as Dale (1693) and Geoiiroy (1741), extol the virtues of the 

 root as a remedy for the bite of the rattlesnake, or of a rabid dog. 

 Serpentary was introduced into the London Pharmacopoeia in 1C50. 



Description — The snake-root of commerce includes the rhizome, 

 which is knotty, contorted, scarcely 1 inch in length hy -| of an inch in 

 thickness, bearing on its upper side the short bases of the stems of 

 previous years, and throwing off from the undei', numerous, slender, 

 matted, branching roots, 2 to 4 inches long. The rhizome is often still 

 attached to portions of the weak, herbaceous stem, which sometimes 

 bears the fruit, — more rarely flowers and leaves. The drug has a dull 

 brown hue, an aromatic odour resembling valerian but less unpleasant, 

 and a bitterish aromatic taste, calling to mind camphor, valerian and 

 turpentine. 



Microscopic Structure — In the rhizome, the outer layer of the 

 bark consists of a single row of cuboid cells ; the middle cortical portion 

 {mesophkeum') of about six layers of larger cells. In the liber, which 

 is built up of numerous layers of smaller cells, those belonging to the 

 medullary rays are nearly cuboid with distinctly porous walls, those of 

 the liber bundles bein;; smaller and arranged in a somewhat crescent- 



shaped manner. Groups of short, reticulated or punctuated vessels 

 alternate in the woody rays with long, porous, ligneous cells; those close 

 to the pith having thick walls. The largest colls of all are those com- 

 posing the pith ; the latter, seen in transverse section, occupies iiot the 

 very centre of the rootstock, but is found nearer to its upper side. The 

 rootlets exhibit a central fibro-vascular bundle, surrounded by a nucleus 

 sheath. In the mesophloeum both of the rootstock and the rootlets, 

 there occur a few cells containing a yellow essential oil. The other 

 cells are loaded with starch. 



^,^ Essential oil exists in the drug to the 



extent of of about I per cent. ; and resin in nearly the same proportion. 

 The outer cortical layer, as well as the zone of the nucleus-sheath, con- 

 tains a little tannin, and a watery infusion of the drug is cplo^'ea 

 greenish by perchhu^ide of iron. Neutral acetate of lead prccipit^^t;^^ 

 some mucilage as well as the bitter principle, which hatter may a so i^t 

 obtained by means of tannic acid. It is an amorphous, bitter suhstanc^^ 

 which deserves further investigation. By an alkaline solution of tartrac 

 of copper the presence in serpentary of sugar is made evident. 



Commerce— Virginian snake-root is imported from New York an 

 Boston, in bales, casks or ba^-s. 



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