279 ACORUS CALAMUS 



The decorticated rhizomes are therefore inferior to the ordinary 

 ones of commerce. 



The principal constituent of calamus or sweet flag rhizome is 

 volatile oil, which can be obtained by distilling it in a fresh or 

 dried state with water. The dried rhizomes yield about 1*25 per 

 cent, of oil ; this oil has a yellow colour at first, but becomes red 

 by keeping, it is dextrogyrate, and to its presence calamus owes its 

 odour and aromatic pungent taste. The rhizome also contains a 

 bitter principle, termed acorin, which was first isolated by Faust 

 in 1867, and determined by him to be a glucoside; it has since 

 been described by Fliickiger and Hanbury as a very bitter, 

 perfectly crystalline body. To the presence of these two prin- 

 ciples sweet flag rhizome owes its properties ; the other con- 

 stituents, such as starch, &c., are of no importance. 



Adulteration. The rhizome of the common Yellow Flag, Iris 

 Pseudacorus, L., is sometimes mixed with that of the Sweet 

 Flag rhizome when the latter is collected in this country; it is 

 readily distinguished by its darker colour, different structure, 

 and want of aromatic odour and taste. 



Medical Properties and Uses. Sweet flag rhizome was formerly 

 much esteemed as an aromatic stimulant and mild tonic ; but at 

 the present day it is very rarely employed by regular medical 

 practitioners, either in this country or in the United States, 

 though, as stated by Pereira, it might frequently be substituted 

 with good effect for the more costly oriental aromatics. The 

 testimony of many physicians indicate that it is now too rarely 

 prescribed. It has been from the earliest times one of the most 

 popular remedies of the native practitioners of India ; in which 

 country it is to be met with in all the bazaars. Dr. A. T. Thomp- 

 son and Dr. Royle speak highly of its value in intermittent fevers ; 

 either by itself, or in conjunction with other tonics. In Norfolk 

 the powdered rhizome is still employed by the country people 

 for the cure of ague. It has also proved very serviceable in 

 flatulence, flatulent colic, and in atonic dyspepsia ; and Pereira 

 found it of especial value in the dyspepsia of gouty subjects. It 

 is also a useful adjunct to tonic or purgative medicines in cases of 



