GELSEMIUM 343 



in the rhizome they form an interrupted ring of isolated fibres or groups 

 of two or three (Sayre, 1897). 



The drug has a bitter taste, especially conspicuous in the bark, and 

 a very slight aromatic odour. 



The student should observe 



(a) The splintery fracture, 



(b) The radiate structure of the transverse section, 



(c) The purplish colour and small pith of the rhizome, 



(d) The yellowish colour and slightly tortuous appearance of 



the root. 



Constituents. Gelsemium rhizome contains three alkaloids, one only 

 of which, gelsemine, has been obtained crystalline, the others (gelsemi- 

 nine and gelsemoidine) being amorphous. Other constituents are 

 /3-methyla3Sculetin, emodin monomethyl ether, phytosterol, resin and 

 fixed oil. 



Gelsemine, C 20 H 22 N 2 O 2 , has been reported to owe any toxicity it 

 may possess to the presence of accompanying gelseminine but this 

 has been denied ; both of the amorphous alkaloids are strongly toxic. 



/3-methyl8esculetin, C 9 H 5 (CH 3 )0 4 (gelsemic or gelseminic acid, 

 scopoletin, chrysatropic acid), is a product of the hydrolysis of methyl- 

 aesculin, aesculin being a fluorescent substance found in horse-chestnut 

 bark. /3-methyl8esculetin is present in belladonna root and in scopola 

 rhizome ; in alkaline solution it exhibits an intense bluish green 

 fluorescence, and its presence in the drug may easily be demonstrated 

 by shaking a little of the powder with lime water or, better, by shaking 

 with chloroform, filtering and shaking the filtrate with very dilute 

 solution of ammonia. 



Gelsemine must be carefully distinguished from gelsemin, which 

 is a powdered alcoholic extract. 



Uses. Gelsemium resembles hemlock in action but is more strongly 

 depressant. It has been much used for, and appears to relieve, certain 

 forms of neuralgia and sick headache as well as rheumatic and ovarian 

 pains. 



PICRORHIZA 



(Picrorhiza) 



Source, &C. Picrorhiza is the dried rhizome of Picrorhiza Kurroa, 

 Royle (N.O. Scrophularinece), a small plant indigenous to the Alpine 

 Himalayas. 



Description. The rhizomes- are greyish brown, more or less cylin- 

 drical, about 2-5 to 5 cm. long and 4 to 8 mm. thick. They are often 

 deeply wrinkled longitudinally and covered with a thin cork. The 

 surface exhibits the transverse scars of cataphyllary leaves, numerous, 



