ACORUS CALAMUS. 315 



The bitter principle Acorin was first extracted from Acorus 

 Calamus root by Faust, in 18G7, who obtained it in the form of a 

 semi-fluid brown glucoside, containing nitrogen ; but he failed to 

 obtain it in a crystalline form or even as a solid. In attempting 

 to prepare this substance by the tannic acid method, Fllickiger and 

 Hanbury obtained* only a minute quantity of a very bitter 

 substance, which however, was perfectly crystalline. The investi- 

 gation was renewed by ThomSjf who, taking advantage of the 

 property possessed by charcoal of absorbing bitter substances* 

 attained more definite results. A quantity of perfectly dry 

 rhizome, cut small, was macerated for two days, with five times its 

 weight of distilled water, the liquor was then strained off and the 

 residue pressed, after which the marc was stirred with a fresh 

 quantity of distilled water, and again pressed. The united filtered 

 liquor was allowed to digest for two days with freshly washed and 

 ignited animal charcoal, with frequent shaking, at the end of which 

 time it w^as entirely deprived of bitterness. The charcoal was 

 washed on a filter w4th water as long as the filtrate showed any 

 turbidity, then after being dried on a water-bath, it was boiled 

 with 90 per cent, alcohol ; this alcoholic extract was filtered, the 

 alcohol distilled off and the turbid residual liquor shaken with 

 ether. Upon evaporation of the ether, and drying over sulphuric 

 acid, the bitter principle was obtained as a thick, clear, honey- 

 yellow balsam, neutral in reaction, and with a faintly aromatic 

 odour and very bitter aromatic taste. It was found to be insoluble 

 in water, dilute acids and alkalies, but perfectly and easily soluble 

 in absolute alcohol, methylic alcohol, ether, benzol, toluol, 

 chloroform, carbon disulphide, and acetone. The yield of this 

 body — which has been named acorin, and is represented by the 

 formula CggHgoOg — was only 0-1854 per cent. AVhen treated 

 with dilute acids and alkalies in a current of hydrogen, acorin 

 splits up into essential oil of calamus and a sugar ; but when the 

 reaction takes place in atmospheric air, the oil readily oxidizes and 

 is converted into a neutral resin, acordin, identical with resin, 

 occurring in the rhizome. This resin, wiien reduced from alkaline 

 solution by nascent hydrogen, gives the essential oil and sugar as 

 final products. From the extract remaining after shaking out the 



* Pharmacocjraphia, 2nd Ed., p. 678, and Hist, des Drogues, ii., p. 499. 

 t Archiv. der Pharm., 1886, p. 465. 



