•592 ARISTOLOCHIACE^. 



or Colubrina, i.e. snake-root, to the rhizome of Polygonum Bistorta, L. 

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

 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 Gerarde's 

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

 species of Aristolochia from Crete with what he calls " that snake-weed 

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

 at South Lambeth, anno 1G32." It was very briefly noticed by 

 Cornuti in his Canadensium Plantarum Hiatoria (1635), and in a 

 much more intelligent manner by Parkinson in 1640. These authors, 

 as well as Dale (1693) and Geoflroy (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 1650. 



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

 which is knotty, contorted, scarcely 1 inch in length b}^ I of an inch in 

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

 previous years, and throwing ofi' from the under, 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 

 (inesophlceum) 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 being 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 cells of all are those com- 

 posing the pith ; the latter, seen in transverse section, occupies not 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. 



Chemical Composition — Essential oil exists in the drug to the 

 extent of of about {r per cent. ; and resin in nearly the same pro])ortion. 

 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 coloured 

 greenish by perchloride of iron. Neutral acetate of lead precipitates 

 some mucilage as well as the bitter principle, which latter may also be 

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

 which deserves further investigation. By an alkaline solution of tartrate 

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



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

 Boston, in bales, casks or bags. 



