BARBERRY BARK.

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a pigment identical with that already described as present rn the wongshy,or fruit of the Gardenia grandiflora. The colour of saffron may be obtainedfrom it by first exhausting with ether, whereby fatty and resinous matters areremoved, and treating the residue with water; the aqueous solution is preci-tated with acetate of lead, and the precipitate is treated as diredted for thatsimilarly obtained from wongshy.

Crocin is a rose-coloured inodorous powder, which turns brown by heat, andis decomposed at 200°; it is soluble in water, alcohol, and alkaline solutions,imparting to them an orange colour. Crocin is hardly soluble in ether; strongsulphuric acid dissolves it, the liquid assuming first a blue, next a violet colour.Boiling with dilute sulphuric acid splits crocin up into glucose and crocetin,an amorphous deep red substance, almost insoluble in water, but soluble inalcohol. Its formula is stated to be C 2 oH 2 60 n.

Barberry Bark.

The substance known as barberry bark and root is obtained from theBerberis vulgaris , a native shrub of Central Europe, and growing wild even inIndia: it is used as a dye-material, and contains a yellow pigment, chieflyaccumulated in the bark, but met with in the wood as well as the root of theshrub, which latter bears some likeness in outward appearance to ipecacuanha.The colour of the root is yellowish, and its taste bitter. The colouring prin-ciple of the barberry differs very essentially from the other yellow dies, inas-much as berberine is a nitrogenous substance,—in fadl, an alkaloid,—and isalso met with in Colombo root, in the root of Cocculus palmatus, and also,according to M. Dyson Perrins, in the Hydastis canadensis, to the extent of4 per cent; the yellow Assam wood ( Woodumpar ), of which the only specimenpresent in Europe is at the India Museum ; a peculiar root from Rio Grande,Brazil; the yellow bark from Bogota (7 per cent), from the Pachnelo, a vege-table produdt, of which only one sample exists at the Kew Botanical Museum ;the Coptis tecta, or Mahmira, a ranunculaceous plant, native of Hindostan andChina (8 per cent).

The substance which MM. Chevallier and Pelleton extradted from theXanthoxylum clava Herculis, a shrub belonging to the Rutaceae, is nothingelse than berberine. Berberine may be obtained from the root by adding, to apreviously concentrated aqueous decodtion, alcohol, which precipitates foreignmatters. T-he liquid is filtered, and the alcohol removed by distillation ; aftersome time the concentrated fluid deposits yellow needles of berberin, whichare purified by re-crystallisation from water.

The commercial extracts of barberry root and bark deposit, on standing,crystals of berberine, which the root contains to an amount of 1-3 per cent.

Berberine has the following properties :—It forms yellow, silky, needle-shapedcrystals, soluble in 500 parts of water at 12°, very soluble in hot water and hotalcohol, insoluble in ether; its salts are yellow, and generally not very soluble ;nascent hydrogen converts it into a colourless basic substance, C 20 H 2I N 0 4 ,hydroberberin ; a dilute solution of iodine in iodide of potassium precipitatesthe alcoholic solutions of the salts of berberine, producing green, mother-of-pearl-like, shining, scaly crystals, which resemble chrysanilin, and, like that,fix upon fibres without the use of mordants.

The root and concentrated liquid extradts of barberry are employed for