The ipecacuanha plant in India has been tried under a variety of conditions as regards sun and shade, but thus far with only a moderate amount of success. The best results are those that have been obtained at Rungbi, 3000 feet above the sea, where the plants, placed in glazed frames, were reported in May 1873 as in the most healthy condition.[1386]
Description—The stem creeps a little below the surface of the soil, emitting a small number of slightly branching contorted roots, a few inches long. These roots when young are very slender and thread-like, but grow gradually knotty and become by degrees invested with a very thick bark, transversely corrugated or ringed. Close examination of the dry root shows that the bark is raised in narrow warty ridges, which sometimes run entirely round the root, sometimes encircle only half its circumference. The whole surface is moreover minutely wrinkled longitudinally. The rings or corrugations of a full sized root number about 20 in an inch; not unfrequently they are deep enough to penetrate to the wood.
The root attains a maximum diameter of about ²/₁₀ of an inch; but as imported, a large proportion of it is much smaller. The woody central part is scarcely ¹/₂₀ of an inch in diameter, subcylindrical, sometimes striated, and devoid of pith.
Ipecacuanha is of a dusky grey hue, occasionally of a dull ferruginous brown. The root is hard, breaks short and granular (not fibrous), exhibiting a resinous, waxy, or farinaceous interior, white or greyish. The bark, which constitutes 75 to 80 per cent. of the entire root, may be easily separated from the less brittle wood. It has a bitterish taste and faint, musty smell; when freshly dried it is probably much more odorous. The wood is almost tasteless. In the drug of commerce the roots are always much broken, and there is often a considerable separation of bark from wood; portions of the non-annulated, woody, subterraneous stem are always present.
During the last few years there has been imported into London a variety of ipecacuanha, distinguished as Carthagena or New Granada Ipecacuanha, and differing from the Brazilian drug chiefly in being of larger size. Thus, while the maximum diameter of the annulated roots of Brazilian ipecacuanha is about ²/₁₀ of an inch, corresponding roots of the New Granada variety attain nearly ³/₁₀. The latter, moreover, has a distinct radiate arrangement of the wood, due to a greater developement of the medullary rays, and is rather less conspicuously annulated. Lefort (1869) has shown that the New Granada drug is a little less rich in emetine than the ipecacuanha of Brazil.
Mr. R. B. White, of Medellin in the valley of the Cauca, New Granada, near which place the drug has been collected, has been good enough to send us herbarium specimens of the plant with roots attached; they agree entirely with Cephaëlis Ipecacuanha.
Microscopic Structure—The root is coated with a thin layer of brown cork-cells; the interior cortical tissue is made up of a uniform parenchyme, in which medullary rays cannot be distinguished. In the woody column they are obvious; the prevailing tissue consists of short pitted vessels. The cortical parenchyme and the medullary rays are loaded with small starch granules. Some cells of the interior part of the bark contain however only bundles of acicular crystals of oxalate of calcium.
Chemical Composition—The peculiar principles of ipecacuanha are Emetine and Ipecacuanhic Acid, together with a minute proportion of a fœtid volatile oil. The activity of the drug appears to be due solely to the alkaloid, which taken internally is a potent emetic.
Emetine, discovered in 1817 by Pelletier and Magendie, is a bitter substance with distinct alkaline reaction, amorphous in the free state as well as in most of its salts; we have succeeded in preparing a crystallized hydrochlorate.
The root yields of the alkaloid less than 1 per cent.; the numerous higher estimates that have been given relate to impure emetine, or have been arrived at by some defective methods of analysis.[1387]