Description—The seeds are somewhat globular or ovoid, a little compressed, ⁴/₁₀ to ⁸/₁₀ of an inch in diameter and weighing 20 to 40 grains. They are of a bluish or greenish grey tint, smooth, yet marked by slightly elevated horizontal lines of a darker hue. The umbilicus is surrounded by a small, dark brown, semilunar blotch opposite the micropyle. The hard shell is from ¹/₂₅ to ²/₂₅ of an inch thick, and contains a white kernel; representing from 40 to 50 per cent. of the weight of the seed. It separates easily from the shell, and consists of the two cotyledons and a stout radicle. When a seed is soaked for some hours in cold water, a very thin layer can be peeled from the surface of the testa. The kernel is bitter, but with the taste that is common to most seeds of the family Leguminosæ.
Microscopic Structure—The outer layer of the testa, the epidermis above alluded to, is composed of two zones of perpendicular, closely packed cells, the outer measuring about 130 mkm., the inner 100 mkm. in length and only 5 to 7 mkm. in diameter. The walls of these cylindrical cells are thickened by secondary deposits, which in transverse section show usually four or more channels running down nearly perpendicularly through the whole cell.
The spongy parenchyme, which is covered by this very distinct outer layer, is made up of irregular, ovate, subglobular or somewhat elongated cells with large spaces between them, loaded with brown masses of tannic matter, assuming a blackish hue when touched with perchloride of iron. The thick walls of these cells frequently exhibit, chiefly in the inner layers, undulated outlines. The tissue of the cotyledons is composed of very large cells, swelling considerably in water, and containing some mucilage (as may be ascertained when thin slices are examined in oil), small starch granules, fatty oil, and a little albuminous matter.
Chemical Composition—According to the medical reports alluded to in the Pharmacopœia of India (1868), Bonduc seeds, and still more the root of the plant, act as a powerful antiperiodic and tonic.
The active principle has not yet been adequately examined. It may perhaps occur in larger proportion in the bark of the root, which is said to be more efficacious than the seeds in the treatment of intermittent fever.[819]
In order to ascertain the chemical nature of the principle of the seeds, one ounce of the kernels[820] was powdered and exhausted with slightly acidulated alcohol. The solution after the evaporation of the alcohol was made alkaline with caustic potash, which did not produce a precipitate. Ether now shaken with the liquid, completely removed the bitter matter, and yielded it in the form of an amorphous white powder, devoid of alkaline properties. It is sparingly soluble in water, but readily in alcohol, forming intensely bitter solutions; an aqueous solution is not precipitated by tannic acid. It produces a yellowish or brownish solution with concentrated sulphuric acid, which acquires subsequently a violent hue. Nitric acid is without manifest influence. From these experiments, we may infer that the active principle of the Bonduc seed is a bitter substance not possessing basic properties.
Uses—The powdered kernels either per se, or mixed with black pepper (Pulvis Bonducellæ compositus Ph. Ind.), are employed in India against intermittent fevers and as a general tonic.
The fatty oil of the seeds is sometimes extracted and used in India; it was shown at the Madras Exhibitions of 1855 and 1857.
LIGNUM HÆMATOXYLI.
Lignum Campechianum v. Campescanum; Logwood, Peachwood; F. Bois de Campèche, Bois d’Inde; G. Campecheholz, Blauholz.