Description. Odourless; taste, bitter and acrid.

Macroscopical. Slices, sub-reniform or ovate in outline, about 1 to 3 by 1 to 2 cm. and 2 to 5 mm. thick; edges, yellowish-brown; slices, firm and breaking readily with a short mealy fracture; transverse surfaces, white and starchy and exhibiting numerous scattered fibro-vascular bundles; occasional sub conical pieces from the apex and irregular pieces from the base of the corm, also sometimes in longitudinal slices. The cut surface is immediately coloured yellow by hydrochloric acid.

Microscopical. Epidermis of rectangular to polygonal cells with brown pitted walls, slightly wavy anticlinal walls, and occasional stomata. Ground tissue of very thin-walled polyhedral parenchymatous cells, about 50 to 100 microns in diameter, filled with starch grains, simple or usually 2- to 3 - or up to 7- compound, individual grains spherical, or polyhedral, or muller-shaped, about 6 to 12 to 16 to 30 microns in diameter, with a triangular or stellate central hilum; also numerous slender conducting strands with narrow spiral or annular vessels.

Acid-insoluble ash. Not more than 0-5 per cent.

Foreign organic matter. Not more than 2-0 per cent.

Assay. Mix 20-0 g., in coarse powder, with 30 ml. of alcohol (95 per cent), and heat on a water-bath for about fifteen minutes. Transfer to an apparatus for the continuous extraction of drugs, and extract with alcohol (90 per cent) for three hours. Cool the extract, set aside for half an hour, and filter, washing the filter with alcohol (90 per cent) until complete extraction of the alkaloids is effected. Evaporate the filtrate to dryness on a water-bath, wash the residue into a separator with 20 ml. of a 20 per cent w/v solution of sodium sulphate and 50 ml. of solvent ether, shake well, allow to separate, run the lower layer into a second separator containing 50 ml. of solvent ether, again shake well, and separate.

Wash the dish with a further 5 ml. of a 20 per cent w/v solution of sodium sulphate, transfer to the first separator, shake, separate, run into the second separator, shake, and again separate. Repeat the washing of the dish and contents of the two separators in the same manner with a further 5 ml. of the solution of sodium sulphate and then with three quantities, each of 5 ml., of water.

Mix all the aqueous liquids, heat on a water-bath until the ether is completely expelled, cool, add 0-2 g. of powdered talc, and make up to 50 ml. with the solution of sodium sulphate. Allow to stand for about an hour, shaking frequently, and filter, rejecting the first 5 ml. of the filtrate. Take 40 ml. of the filtrate, representing ' 16 g. of Colchicum Corm, shake with 40 ml. of solvent ether, separate, and wash the ether with three successive quantities, each of 5 ml., of water. Mix the aqueous liquids, add 50 ml. of chloroform, and shake; add 2 ml. of N/l sodium hydroxide and again shake well. Run off the lower layer into a second separator containing 2 ml. of N/10 sodium hydroxide and 15 ml. of water, shake, separate, and filter the chloroform solution through a double filter.

Continue the extraction with further quantities of chloroform, washing each portion with the alkaline liquid contained in the second separator, and filtering as before. Remove the chloroform, add 2 ml. of alcohol (95 per cent), evaporate, add a further 2 ml. of alcohol (95 per cent), evaporate, dry over phosphorus pentoxide at a pressure not exceeding 5 mm. of mercury for three hours, and weigh the residue.

To the weighed residue, add 10 ml. of water and allow to stand for a few minutes. Filter through a small filter, and wash the dish and filter with further small quantities of water until complete extraction of the alkaloids is effected. Dissolve any insoluble matter on the filter in a little alcohol (95 per cent), transfer to the dish containing the remainder of the insoluble matter, evaporate, dry over phosphorus pentoxide at a pressure not exceeding 5 mm. of mercury for three hours, and weigh. To obtain the weight of the alkaloids of colchicum corm, subtract the weight so obtained from the weight of the residue previously determined.

POWDERED COLCHICUM CORM (Colchici Cormi Pulvis)
Description. Light grey. Diagnostic structures: occasional fragments of epidermis of isodiametric cells, 40 to 60 to 95 microns in width, with indistinct pits on the anticlinal walls and very rarely with nearly circular stomata; starch grains, numerous, free or enclosed in the abundant thin-walled parenchyma, simple or usually 2- to 3- or up to 7-compound, with characteristic hilum, individual grains, frequently muller-shaped; vessels, spiral or annular, up to 30 microns in width; calcium oxalate, absent.

Standard for alkaloids; Acid-insoluble ash; Foreign organic matter. Complies with the requirements for alkaloids, Acid-insoluble ash, and Foreign organic matter stated under Colchicum Corm.
Preparations. Colchicum Liquid Extract. Colchicum Tincture.

COLCHICUM LIQUID EXTRACT Colch. Liq. Ext.
Colchicum Liquid Extract contains 0-3 per cent w/v of the alkaloids of colchicum corm (limits, 0-27 to 0-33).
Colchicum Corm, in moderately fine powder....... 1000 g.
Alcohol (70 per cent) . . . a sufficient quantity

Exhaust the Colchicum Corm by percolation with Alcohol (70 per cent), reserving the first 600 ml. of the percolate. Remove the alcohol from the remainder of the percolate and evaporate the residue to a soft extract under reduced pressure at a temperature not exceeding 60�. Dissolve the extract in the reserved portion. Determine the proportion of alkaloids in the liquid thus obtained by the Assay described below. To the remainder of the liquid add sufficient Alcohol (70 per cent) to produce a Colchicum Liquid Extract of the required strength. Allow to stand for not less than twenty-four hours; filter if necessary.

Alcohol content. 60 to 70 per cent v/v.
Assay. Evaporate 20 ml. to dryness on a water-bath and complete the Assay described under Colchicum Corm, commencing at the words 'wash the residue into a separator . . 40 ml. of the nitrate represents 16 ml. of the colchicum liquid extract being assayed.
Preparation. Colchicum Tincture, see below.

COLCHICUM TINCTURE Colch. Tinct.
Colchicum Tincture contains 0-03 per cent w/v of the alkaloids of colchicum corm (limits, 0-027 to 0-033).
Colchicum Liquid Extract . . . .100 ml.
Alcohol (70 per cent), sufficient to produce . . 1000 ml.
Mix; allow to stand for not less than twelve hours; filter.
Alcohol content. 67 to 70 per cent v/v.
Assay. Evaporate 200 ml. to dryness on a water-bath and complete the Assay described under Colchicum Corm, commencing at the words 'wash the residue into a separator . . . 40 ml. of the nitrate represents 160 ml. of the colchicum tincture being assayed.

Cultivation. Requires light, sandy loam, enriched with decayed manure or leaf-mould. Plant the bulbs 3 inches deep and 3 inches apart in July or August, in moist beds or rockeries, shrubbery, borders or lawns near shade of trees. The foliage dies down in June and July, and does not reappear until after the plant has flowered. It may also be propagated by seeds sown J inch deep in a bed of fine soil outdoors in August or September, or in pans or boxes of similar soil in cold frame at the same time, transplanting seedlings 3 inches apart when two years old; or by division of bulbs in August. Seedling bulbs do not flower till four or five years old.

The active principle is said to be an alkaline substance of a very poisonous nature called Colchinine. It is acrid, sedative, and acts upon all the secreting organs, particularly the bowels and kidneys. It is apt to cause undue depression, and in large doses acts as an irritant poison. Dr. Lindley relates the case of a woman who was poisoned by the sprouts of Colchicum, which had been thrown away in Covent Garden Market and which she mistook for onions.

The Hermodactyls of the Arabians, formerly celebrated for soothing pains in the joints, are said to be this plant.

The corm or root is usually sold in transverse slices, notched on one side and somewhat reniform in outline, white and starchy internally, about ⅛ inch thick, and varying from � to 1 inch in diameter. Taste sweetish, then bitter and acrid. Odour radish-like in fresh root, but lost in drying.