History—Dioscorides drew attention to the poisonous properties of Κολχικὸν, which he stated to be a plant growing in Messenia and Colchis.[2615]
This character for deleterious qualities seems to have prevented the use of colchicum both in classical and mediæval times. Thus Tragus (1552) warns his readers against its use in gout, for which it is recommended in the writings of the Arabians. Jacques Grévin, a physician of Paris, author of Deux Livres des Venins, dedicated to Queen Elizabeth of England, and printed at Antwerp in 1568, observes—“ce poison est ennemy de la nature de l’homme en tout et par tout.” Dodoens calls it perniciosum Colchicum; and Lyte in his translation of this author (1578) says—“Medow or Wilde Saffron is corrupt and venomous, therefore not used in medicine.” Gerarde declares the roots of “Mede Saffron” to be “very hurtfull to the stomacke.”
Wedel published in 1718, at Jena, an essay De Colchico veneno et alexipharmaco, in which, to show the great disfavour in which this plant had been held, he remarks,—“hactenus ... velut infame habitum et damnatum fuit colchicum, indignum habitum inter herbas medicas vel officinales....” He further states that, in the 17th century, the corms were worn by the peasants in some parts of Germany as a charm against the plague.
In the face of these severe denunciations, it is strange to find that in the London Pharmacopœia of 1618 (the second edition), “Radix Colchici,” as well as Hermodactylus, is enumerated among the simple drugs; and again in the editions of 1627, 1632 and 1639. It is omitted in that of 1650, and does not reappear in subsequent editions until 1788, when owing to the investigations of Störck (1763), Kratochwill (1764), De Berge (1765), Ehrmann (1772), and others, the possibility of employing it usefully in medicine had been made evident.
Development of the Corm[2616]—At the period of flowering, the corm is surrounded with a brown, closed double membrane or tunic, which is prolonged upwards into a sheath around the flowering stem; at the base of the corm is a tuft of simple roots. On removing the membranes, we find a large, ovoid, fleshy body (Corm No. 1), marked at its apex by a depressed scar, the point of attachment of the flower-stem of the previous year; it is on one side flattened, and traversed by a shallow longitudinal furrow, from the upper part of which arises a much smaller and rudimentary corm (No. 2), bearing a flower-stem. After the production of the flower in the autumn, Corm No. 2 increases in size, throwing up as spring advances its fruit-stem and leaves, and acquires, after these latter have come to maturity, its full development. Corm No. 1 on the other hand, having performed its functions, shrivels and diminishes in size, in proportion as No. 2 advances to maturity, and ultimately decays, leaving a rounded cicatrix, showing its point of attachment to its successor.
Collection—In England the corms are usually dug up and brought to market in July, at the period between the decay of the foliage and the production of the flower, or even after the latter has appeared. For some preparations, they are used in the fresh state. If to be dried, it is customary to slice them across thinly and evenly with a knife, and to dry the slices quickly in a stove with a gentle heat; the membranes are afterwards removed by sifting or winnowing.
Schroff has stated, as the result of his experiments,[2617] that the corms possess the greatest medicinal activity when collected in the autumn during or after inflorescence; that they ought to be dried entire, by exposure to the sun and air; and that if thus preserved, they lose none of their strength, even if kept for several years.
Description—The fresh corm is conical or inversely pear-shaped, about 2 inches long by an inch or more wide, rounded on one side, flattish on the other, covered by a bright brown, membranous skin, within which is a second of paler colour. When cut transversely, it appears white, firm, fleshy and homogeneous, abounding in a bitter, starchy juice, of disagreeable odour. The dried slices are inodorous, and have a bitterish taste. They should be of a good white, clean, crisp and brittle,—not mouldy or stained.
Microscopic Structure—The outer membrane is formed of tangentially-extended cells, with thick brownish walls; the main body of the corm, of large thin-walled, more or less regularly globular cells, loaded with starch, and interrupted by vascular bundles containing spiral vessels. The original form of the starch granules is globular or egg-shaped, but from mutual pressure and agglutination, many are angular or truncated. A large proportion are more or less compound, consisting of several granules united into one. In all, the hilum is very distinct, appearing in some as a mere point, but in most as a line or star.
Chemical Composition—The corms contain Colchicin (see next article), starch, sugar, gum, resin, tannin, and fat. When sliced and dried, they lose about 70 per cent. of water.[2618] By drying, the (probably) volatile body upon which the odour of the fresh corm depends, is lost.