This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol2", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Colchicum is the product of Colchicum autumnale, a beautiful little plant commonly called meadow saffron, which grows wild in Europe, where it is also cultivated for medical use. The root, or in botanical language, the cormus, formerly called the bulb, is in perfection in the summer, near the close of which it puts forth an offset, which grows at the expense of the maternal cormus, and sends up flowers in the autumn. in the following spring, the old cormus has shrunk considerably, and gradually goes on diminishing till it perishes; while the new one flourishes, sends up the fruit and leaves, and attains its full growth in summer. it is generally thought that the virtues of the root depend very much upon the stage of its growth, and that the proper period for collecting it is from the early part of June to the middle of August; as, before that time, it has not become fully developed, and afterwards deteriorates by giving up its substance to its offspring. All parts of the plant, the leaves, flowers, and fruit, possess medical virtues, as well as the cormus; but it is only this and the seeds that are recognized as officinal.
1. Colchicum Root. When fresh, this is shaped somewhat like the bulb of the tulip, though rather smaller, is covered by a brown membranous coating, is white, solid, and fleshy within, and contains an acrid milky juice. After being dried, and deprived of its coating, which easily separates, it appears rounded on one side, and somewhat flattened on the other, where there is generally a vertical groove running from the top to the bottom of the cormus. Generally, however, before being dried, it is cut into thin transverse slices, sometimes into vertical slices, in which state it is usually kept in our shops. These slices, if transverse, are circular, with a notch on one side; if vertical, are heart-shaped. They are a little more than a line in thickness; and their cut surface has a grayish-white colour, and starchy appearance. They have little smell, but a hot, acrid, bitter taste, and yield their virtues readily to vinegar, wine, or spirit. They are injured by keeping, and are very apt to be of inferior quality, either from this cause, or from original defect in the cormus. The best test of their efficacy is the degree in which they possess the bitter taste.*
2. Colchicum Seeds. These are collected in the summer, when quite ripe. They are about the eighth of an inch in diameter, of a reddish-brown colour more or less dark on the outside, whitish within, and similar in appearance to black mustard seed. They are inodorous, and have an acrid bitter taste. Like the cormus, they readily yield their virtues to vinegar, wine, or spirit. They are less apt to suffer deterioration in drying, or by time.
Active Principle. The activity of colchicum depends on a peculiar alkaline principle called colchicia, which, when first discovered, was supposed to be identical with Veratria, but which Geiger and Hesse demonstrated to be quite distinct. For the mode of preparing it, and its characteristic properties, see the U. S. Dispensatory. independently of other peculiarities, it differs from Veratria in being crystallizable, soluble in water, and destitute of acrid and sternutatory properties. it must be a powerful poison, as one-tenth of a grain killed a young cat in twelve hours. it exists in the seeds and cormus, and probably in all parts of the plant.*
* From experiments made by Professor Schroff, of Vienna, it would appear that some of our notions, on the subject of the relative value of the bulb and seeds, and the proper season for gathering the bulb, must be modified. He found that the dried bulb, dug in the autumn, is superior in efficacy to the seeds: that the bulb dug in the autumn, and dried simply by exposure to the sun and air, loses none of its strength either in the drying process, or subsequently by keeping; that the dried bulb is stronger than the fresh in equal weights; and that both fresh and dried bulbs are much stronger dug in the autumn than in the summer. The drying of the whole bulb by exposure to the sun, and in the open air, is better than any other method; and good bulbs, kept free from insects and other avoidable source of injury, will retain their virtues unimpaired for several years. (Am. Journ. of Pharm., July, 1857, p. 324; from Oester. Zeitschr. fur pract. Heilkunde.) - Note to the second edition.
Colchicum is locally somewhat irritant; but not violently so. in moderate medicinal doses, it is believed often to act beneficially in disease, without in any discoverable manner deranging the healthy functions. Hence it must be considered as an alterative; and, as it is given with a view more to an influence of this kind than for its sensible effects, it would appear properly to belong to the present class.
More largely given, it produces very sensible and important effects. One of the first and most common of these is nausea; and there are few medicines, the nauseating effect of which is more distressing to the patient. it is also very apt to purge, and in considerable doses to vomit; and, if given to a certain amount, usually produces both active vomiting and purging, with oppressive nausea, and great feelings of weakness and prostration.
When not carried off by purging, it has a tendency to act on the secretions, and may indeed be looked on as a universal secretory stimulant, acting on some one of the functions preferably, or on two or more jointly, according to the special circumstances of the case. it most strikingly affects the skin and kidneys, sometimes producing copious diuresis, sometimes not less copious diaphoresis, being most disposed to the former effect when the patient is about, and drinks freely of cold water; to the latter, when he is warm in bed, and especially when its use is conjoined with that of an opiate, or warm drinks, or both. Occasionally it is said to cause profuse salivation. it is thought also, in some instances, to stimulate the hepatic and bronchial secretions, and to act as an emmenagogue. Some have ascribed to it the property of promoting uterine contraction, and thus hastening protracted labours. These latter effects, however, are only occasional, and cannot be relied on.