320

Materia Medica.

Hrlleborvs nigcr.

PART II.

phate of magnesia, purple. According to Chevreul, logwoodcontains a volatile oil, tannin, two kinds of colouring matter,one of which is soluble both in water and alcohol, the othersoluble in alcohol only; acetate of lime and of potass '; and apeculiar substance, which is procured in small brilliant crystals,of a reddish-white colour, and a slightly astringent, bitter, andacrid taste; and which he named Hematin. «

Medical properties and uses. — Logwood is supposed to beastringent: but this is a questionable opinion, for although itproduces an ink with sulphate of iron, it possesses no acerbity,and does not produce a precipitate with gelatine. 3 It is em-ployed in diarrhoea, and in the latter stage of dysentery; butthe extract is more usually ordered. It has the advantage ofgiving tone to the general system, and thus obviates the laxstate of the intestines. The decoction may be taken in dosesof two or three fluid ounces, frequently repeated.Officinal preparation. Extractum Hcematoxyli, L.HELLEBOR.US. Spec. Plant. Willd. ii. 1335.CI. 13. Ord. 6. Polyandria Polygynia. Nat. ord. Multisiliquae, Linn.

Ranunculaceae, Juss.G. 1089. Calyx none. Petals five or more. Nectaries bilabiate,

tubular. Capsules many seeded, nearly erect.Species 3. H. niger. Black Hellebore. Med. Bot. 2ded. 473. t. 169.Species 6. H.Jbetidus. Foetid Hellebore, or Bear's foot. Med. Bot,2ded. 477. t. 170 Smith. Flor. Brit. 598. Eng. Bot. t. 613.

1. HeLLEBORUS NIGER.

Officinal. Hellebori nigri radix, Lond. Hellebori nigri

radix, Edin. ------•, (Melampodium 4 ) radix, Dub. The root of

Black Hellebore.

Syn. Hellebore (F-), Schwartze Niesswurzel (G.), Ellebro negro (/.), Helleboronegro (S.)> Kali Koothie (H.), Khurbuc usivud {Arab.)

Black hellebore, so named from the dark colour of the root,is a native of Austria, the Apennines, and Italy; flowering fromDecember till March; whence it has been called Christmasrose, and has obtained a place in our gardens. b The root isperennial, transverse, rough, knotted, externally black, inter-nally whitish, and sends off' many depending fibres. The leaves,which are deep green, spring directly from the root on longmaculated petioles; and are composed generally of five leaflets,pedate, two being supported on one partial petiole on eachside, and one terminal: the leaflets are ovato-lanceolate, smooth,shining, and coriaceous, with the upper half of each sparsely

1 Annates dc Chimie, lxvii. 254. Thomson's Chemistry, v. 206.

2 To obtain hematin, digest logwood rasped in water of the temperature 125°,filter and evaporate to dryness. lSigest the residue for a whole day in alcohol of sp.gr. 0.837, filter and concentrate by evaporation; then add a small portion of water,evaporate a little farther, and leave it to itself. Crystals of hematin are formed inabundance.

3 Vide Bancroft, Phil, of Permanent Colours, 2d ed. vol. ii. p. 395.

4 Named from ^Melampus, a soothsayer, who first gave it as a purgative.

5 It was first cultivated in Britain by Gerarde in J 59G,