370 SUBTERRANEAN ORGANS 



The parenchymatous medullary rays readily break down and the 

 vascular bundles then separate into strands giving to the drug a 

 coarsely fibrous appearance. All the parenchymatous cells are 

 loaded with starch in simple or compound (two to three) grains. The 

 odour is slight and agreeable ; the taste at first bitterish but subse- 

 quently distinctly numbing. 



Constituents. Kava rhizome contains about 5- 8 per cent, of 

 resin, part of which (a-kava resin) is soluble in petroleum spirit, the 

 remainder (/3-kava resin) being soluble in ether. In addition it 

 contains methysticin (colourless crystals melting at about 137 ; 0'3 

 per cent.), yangonin (colourless crystals melting at 151; 0*18 per 

 cent . ) , and pseudomethysticin (yellowish crystals melting at 113; 0*18 

 per cent.) ; these readily crystallise from a concentrated alcoholic 

 tincture of the drug. Further constituents are an alkaloid, kavaine, 

 two glucosides and an abundance of starch. The medicinal activity 

 appears to be due to the resins. 



Uses. Kava rhizome is employed medicinally as an antiseptic 

 and diuretic in gonorrhoea and cystitis. The purified resin dis- 

 solved in sandalwood oil forms a proprietary preparation for 

 gonorrhoea. It is used in the South Sea Islands for preparing an 

 intoxicating drink, the intoxication being said to affect the power 

 of movement while leaving the intellect clear. 



SERPENTARY RHIZOME 



(Serpentary Root, Virginian Snakeroot, Rhizoma 

 Serpentariae) 



Source, &C. Two varieties of serpentary, or, as it is sometimes 

 termed, snakeroot, are official in the British Pharmacopoeia, viz. 

 Virginian snakeroot and Texan or Red River snakeroot. 



Virginian snakeroot is obtained from Aristolochia Serpentaria, Linne 

 (N.O. Aristolochiaceaz) , a small herbaceous plant with slender perennial 

 rhizome, growing in the United States, to the east of the Mississippi. 



Texan or Red River snakeroot is the produce of Aristolochia reticulata, 

 Nuttall, a rather stouter plant, growing, as its name indicates in the 

 south-western States. 



The drug is collected in the autumn and dried. It was known in 

 England in 1632, its use having been undoubtedly learnt from the 

 American Indians, and it found a place in the London Pharmacopoeia 

 of 1650. 



Description. The snakeroot at present in commerce is the variety 

 known as Texan, and is derived from A. reticulata. It consists of a 



