86 ODOllOGRAPHIA. 



the benzene, are dissolved in alcohol and precipitated by basic 

 acetate of lead, which is afterwards eliminated by sulphuretted 

 hydrogen and the curcumine re-crystallised from alcohol. It 

 forms into yellow crystals, having the odour of Vanilla, and 

 exhibiting by reflected light a beautiful blue colouration. Daube 

 assigned to them the formula C\o H^^ O^g. According to 

 Gajewsky, Curcumine is best prepared by washing an ethereal 

 extract of Curcuma with a weak solution of ammonia, and 

 dissolving the residue in concentrated boiling ammonia, then, by 

 passing into the solution a current of carbonic acid, the curcumine 

 is percipitated in a flocular form.* 



On moistening a piece of paper with an alcoholic solution of 

 curcumine, and bringing the paper in contact with an alkali, a 

 beautiful orange-brown colouration is produced, which changes to 

 violet on drying. Boracic acid communicates to curcumine an 

 orange colouration, changing to blue on the addition of an alkaline 

 solution.f 



On the addition of borax to curcumine, a rose-coloured substance 

 is produced, which was named by Schlumberger Eosacyanine, 

 Daube obtained this in the crystalline state. Ivanow Gajewsky, 

 who isolated it by w^arming the alcoholic extract of curcuma with 

 boracic and sulphuric acids, describes it as a crystalline purple 

 powder, giving a green metallic reflection, insoluble in water and 

 soluble in alcohol. Alkalies colour its solution a deep blue. The 

 same chemist also found in the drug a very small proportion of an 

 alkaloid. Kachler found in the aqueous decoction of the root a 

 large quantity of binoxalate of potassium. 



* Curcumine also exists in the roots of Zangiher Cassumunai\'Ro-iih. (formerly 

 called Radix Cassumvnar) and in Curcuma amarissima. Roscoe, C. alta, and C. 

 pettolata, Roscoe ; all of which plants are figured in Roscoe's magnificent work 

 " Monandrous plants of the order Scitaminea?, 1828." 



t This reaction of crude curcumine was discovered by Vogel, as far back as 

 1815, and has since been utilised as a chemical test for the presence of curcuma 

 as an adulterant in powdered rhubarb and mustard. The following expeiiment 

 described by Fliickiger and Hanbury, demonstrates in a striking manner some 

 of these colour reactions : — Place a little pulverised curcuma on blotting paper 

 and moisten it at frequent intervals wdth chloroform, A yellow stain is left 

 on the paper, which, by the action of a weakly acidulated solution of borax, 

 exhibits on drying, a purple tint. On then moistening the paper with a weak 

 solution of ammonia the stain assumes a transient blue colouration. In this 

 way the test can be applied in the examination of rhubarb and mustard for the 

 presence of turmeric or curcuma. 



