The medicinal virtues of mudar, though so long esteemed by the natives of India, were not investigated experimentally by Europeans until the present century, when Playfair recommended the drug in elephantiasis, and its good effects were afterwards noticed by Vos (1826), Cumin (1827), and Duncan (1829). The last named physician also performed a chemical examination of the root-bark, the activity of which he referred to an extractive matter which he termed Mudarine.[1577]
Description—The root-bark of C. procera, as we have received it,[1578] consists of short, arched, bent, or nearly flat fragments, ⅛ to ⅕ of an inch thick. They have outwardly a thickish, yellowish-grey, spongy cork, more or less fissured lengthwise, frequently separating from the middle cortical layer; the latter consists of a white mealy tissue, traversed by narrow brown liber-rays. The bark is brittle and easily powdered; it has a mucilaginous, bitter, acrid taste, but no distinctive odour. The light yellow, fibrous wood is still attached to many of the pieces.
The roots of C. gigantea are clothed with a bark which seems to be undistinguishable from that of C. procera just described. The wood of the root consists of a porous, pale yellow tissue, exhibiting large vascular bundles, and very numerous small medullary rays, consisting of 1 to 3 rows of the usual cells.[1579]
Microscopic Structure—In the root-bark of C. procera, the suberous coat is made up of large, thin-walled, polyhedral, or almost cubic cells; the middle cortical layer, of a uniform parenchyme, loaded with large starch granules, or here and there containing some thick-walled cells (sclerenchyme) and tufts of oxalate of calcium. The large medullary rays are built up of the usual cells, having porous walls and containing starch and oxalate. In a longitudinal section, the tissue, chiefly of the middle cortical layer, is found to be traversed by numerous laticiferous vessels, containing the dry milk juice[1580] as a brownish granular substance not soluble in potash.
The microscopic characters of the root-bark of C. gigantea agree with those here detailed of C. procera. The stems of Calotropis are distinguished by strong liber-fibres, which are not met with in the roots.
Chemical Composition—By following the process of Duncan above alluded to, 200 grammes of the powdered bark of C. gigantea yielded us nothing like his Mudarine, but 2·4 grammes of an acrid resin, soluble in ether as well as in alcohol. The latter solution reddens litmus; the former on evaporation yields the resin as an almost colourless mass. If the aqueous liquid is separated from the crude resin, and much absolute alcohol added, an abundant precipitate of mucilage is obtained. The liquid now contains a bitter principle, which after due concentration may be separated by means of tannic acid.
We obtained similar results by exhausting the bark of C. procera with dilute alcohol. The tannic compound of the bitter principle was mixed with carbonate of lead, dried and boiled with spirit of wine. This after evaporation furnished an amorphous, very bitter mass, not soluble in water, but readily so in absolute alcohol. The solution is not precipitated by an alcoholic solution of acetate of lead. By purifying the bitter principle with chloroform or ether, it is at last obtained colourless. This bitter matter is probably the active principle of Calotropis; we ascertained by means of the usual tests that no alkaloid occurs in the drug. The large juicy stem, especially that of C. gigantea, ought to be submitted to an accurate chemical and therapeutical examination.[1581]
Uses—Mudar is an alterative, tonic and diaphoretic,—in large doses emetic. By the natives of India, who employ it in venereal and skin complaints, almost all parts of the plant are used. According to Moodeen Sheriff,[1582] the bark of the root and the dried milky juice are the most efficient; the latter is however somewhat irregular and unsafe in its action. The same writer remarks that he has found that the older the plant, the more active is the bark in its effects. He recommends that the corky outer coat, which is tasteless and inert, should be scraped off before the bark is powdered for use: of a powder so prepared, 40 to 50 grains suffice as an emetic.
The stems of C. gigantea afford a very valuable fibre which can be spun into the finest thread for sewing or weaving.[1583]