279 ACORUS CALAMUS 



the Pharmacopoeia of India. But it was formerly recognised in 

 both the London and Edinburgh Pharmacopoeias. 



Collection. The rhizomes of sweet flag should be collected late 

 in the autumn, or in the spring ; and after being carefully 

 washed, and freed from their roots, dried with a moderate 

 heat. In the process of drying they shrink to about half their 

 original diameter, but their odour and taste are much improved. 

 In Germany the rhizomes are sometimes peeled before they are 

 dried, but such an operation materially injures their properties, as 

 we have explained below in speaking of their general characters 

 and composition. Formerly the London market was supplied 

 from Norfolk and the banks of the Thames ; but at the present 

 time the rhizome is generally obtained from Germany, although 

 in rare cases also from India. Fliickiger and Hanbury believe 

 that it is brought into Germany from Southern Russia. 



General Characters and Composition. Calamus or sweet flag 

 rhizome as found in commerce, is in flattened, somewhat curved 

 pieces, which are usually some inches in length, and from about half 

 an inch to an inch in diameter. Externally it has a yellowish-brown 

 or fawn colour, and is more or less shrunken and wrinkled; it 

 is marked on its upper surface with the scars and fibrous ves- 

 tiges of the leaves, and on its under surface with numerous little 

 elevated pale-coloured circular dots with a dark centre ; these 

 latter indicating the points from whence the roots arose. The 

 rhizome breaks with a short rough fracture, its texture is spongy 

 or corky, and its colour internally is pale brown and somewhat 

 roseate. Its odour is aromatic and agreeable ; and its taste 

 bitterish, aromatic, and pungent. The Indian variety is said to 

 have a stronger and more agreeable flavour than that obtained 

 in Europe or the United States of America. The rhizome dete- 

 riorates by keeping. The decorticated rhizome, which is some- 

 times imported from Germany, is in greyish-white spongy pieces 

 of variable length. Its odour is similar to the rhizome as ordi- 

 narily prepared, but is not so powerful, as the receptacles con- 

 taining the volatile oil of sweet flag to which the odour is 

 due are more abundant in the external portions of the rhizome. 



