BY REINHARD J. WEBER, PH.G.
From an Inaugural Essay.
Description.—Luffa aegyptiaca, nat. ord. cucurbitaceae, is indigenous to Egypt and Arabia, and is a large climbing vine, with a thin, but very tough light green succulent stem, attaining a length of from ten to thirty feet. The leaves are alternate and palmately lobed, of a light green color and almost destitute of taste. The flowers are monoecious; petals five, united below into a bell-shaped corolla; anthers cohering in a mass; ovary two-celled, style slender, stigmas three. The fruit is elliptical ovate, fleshy and indehiscent, with a green epidermis, longitudinally marked with black lines, varying from ten to fifteen in number; under each of these lines is found a tough woody fibre. The fruit attains a length of from six to twenty-five inches. I have seen a specimen of the fruit, grown in Allentown, Pa., which measured thirty-four and a half inches in length, and nine inches in diameter. When the epidermis is removed it presents a layer of interwoven woody fibres, which may be used like a sponge, being hard and rough when dry, and soft when soaked in warm or cold water; they absorb the latter with the same facility as the ordinary sponge, and have the advantage over the sponge not to wear out by ordinary use for a number of years; hence, the name of "Vegetable Sponge," or "Wash Rag," and its use as a flesh glove. The seeds are numerous, and are almost flat, broadly ovate, three-eighths of an inch long. The testa is of a blackish brown color and rough, cotyledons almost flat, of a yellowish brown color and oily.
Analysis.—An infusion of the epidermis of the fruit (1 to 10) was made and tested for tannin, with tincture of chloride of iron, with sulphate of iron, and Russian isinglass, whereby a trace of tannin was shown, 100 grains of the epidermis thoroughly dried, yielded fifty-four per cent. of residue; on being incinerated at a low heat, the epidermis (dry ?) yielded twelve per cent. of a dark gray ash, one half of which was soluble in water; the ash consisted of silica, carbonates and sulphates of potassium and calcium. The fibrous portion, after being incinerated, yielded sixteen per cent. of ash, partly soluble in water.
The fruit contains a large amount of mucilaginous substance, which yields a white precipitate with solution of subacetate of lead.
An infusion of the fibrous portion, when evaporated to a syrupy consistence, became gelatinous on cooling. The gelatinous mass had all the properties of bassorin, and was free from starch. One troy ounce of the epidermis was powdered, and successively exhausted with benzin, alcohol and water. The benzin solution yielded a small quantity of yellow coloring matter; the alcoholic tincture left chlorophyll and a little extractive, and the infusion gave twenty per cent. of slightly bitter extract.
One troy ounce of the powdered seeds was treated with boiling benzol; the green solution, on being evaporated, yielded two and a half per cent. of a brown, fatty oil, and twelve per cent. of a green mass. The latter, on being treated with very dilute hydrochloric acid, and evaporating the liquid, yielded a minute amount of crystals. Similar crystals were also obtained from the green alcoholic extract of the seeds previously exhausted with benzol. Water afterwards took up nothing of note.
Mode of preparing the fibrous portion.—The fruit is cut longitudinally on one side, stripped of the epidermis, the seeds are then removed, and the net work of fibres is washed thoroughly to get rid of the mucilaginous substance and dried. It is then ready for use. This fibrous portion is the only part of the plant, as far as I know, that has ever been in use.