DOMBA OIL.—The Poonay or Palang tree (Calophyllum Inophyllum), the Alexandrian laurel, is a beautiful evergreen, native of the East Indies, which flourishes luxuriantly on poor sandy soils, in fact where scarcely anything else will grow. The seeds or berries contain nearly 60 per cent. of a fragrant, fixed oil, which is used for burning as well as for medicinal purposes, being considered a cure for the itch. As commonly prepared it has a dark green color. It is perfectly fluid at common temperatures, but begins to gelatinise when cooled below 50 degrees.
THE EARTH-NUT (Arachis hypogæa, or hypocarpogea).—This very singular plant has frequently been confounded with others, partly through the carelessness of travellers, and by the improper use of names, which tended to mislead and confuse. Its common appellative, the earth-nut, has led to the conclusion that it was a species of nut, such as is known in England under the name of "pig nut," "hawk nut," and "ground nut." This, as well as the "earth chesnut," belongs to a totally different genera. On the Continent and in the East Indies a similar confusion had long existed by the appellation of "ground pistachio," which caused the fruit to be confounded with the nut of the tree Pistacia vera. Some resemblance, on the other hand, existing between these—as well as from their being eaten by different nations, and used as an article of food, and also for producing oil—rendered the true description still more difficult. Botanists are, however, no longer at a loss, having well established the nature and character of all these plants. The Arachis "nut" partakes of the nature of the pea or bean of our own country, and is a low annual plant of the order Diadelphia decandria of Linn.; originally from Africa, but now extensively cultivated in every quarter of the globe. It has been naturalised in Europe, and with the climate of the South of France it may be turned to good account.
It has been said to be indigenous in Florida, Peru, Brazil, and Surinam; but the plant may be grown on a light sandy soil, under a moderate heat, equal to that of Italy or the South of France. The class to which it belongs approaches to the pea tribe; but its remarkable difference to this, as to the pulse we know as a bean, is the circumstance of its introducing its fruit or pod—if we may so call it—into the earth, for the purpose of ripening its seed. The Arachis, or earth nut, has obtained its name from this operation. The flowers, leaves, and stems are produced in the ordinary manner we see in the pea tribe. When the yellow flower has withered and the seed fertilised, there is nothing left but the bare stem which had supported it. This stem, in which is the germ of the future fruit and pod, now grows rapidly in a curved manner, with a tendency to arrive shortly on the surface of the ground, into which it penetrates this now naked stem, and sinks into the earth several inches. It is in this obscure position that the fruit takes its ripened form, and is either gathered from its hiding place or left to the future season, when its time of rising into new existence calls it from what was thought its unnatural position.
When mature, it is of a pale yellow color, wrinkled, and forms an oblong pod, sometimes contracted in the middle; it contains generally two seeds. The nuts or peas are a valuable article of food in the tropical parts of Africa, America, and Asia. They are sweetish and almond-like, and yield an oil, when pressed, not inferior in use and quality to that obtained from the olive. The leaf resembles that of clover, and, like it, affords excellent food for cattle. The cake, after the oil is expressed, forms an excellent manure.
The Arachis is usually sown in dry, warm weather, from May to June, and are placed at the distance of eighteen inches from each other. Insects are fond of them; and if the season is cold and unfavorable to them, or the growth retarded, they become musty and bad, or are eaten by insects.
The mode of obtaining the oil is nearly the same as for other pulse or seeds; and under favorable circumstances the Arachis will produce half its weight of oil. When heated and pressed the quantity is very considerably increased. This oil is good for every purpose for which olive or almond oil is used. For domestic purposes it is esteemed, and it does not become rancid so quickly as other oils. Experiments have been made on its inflammable properties, and it is proved that the brilliancy of light was superior to that of olive oil, and its durability was likewise proved to be seven minutes per hour beyond the combustion of the best olive oil, with the additional advantage of scarcely any smoke. In Cochin-China and India it is used for lamps. It is known as Bhoe Moong or Moong Phullee in Bengal, and as Japan or Chinese pulse in Java.
From China this plant was probably introduced into the continent of India, Ceylon, and the Malayan Archipelago, where it is generally cultivated.
In South Carolina the seed is roasted and used as chocolate. The leaves are used medicinally.
It is grown in Jamaica, and there called Pindar nut.
That the culture of the Arachis in warm climates, or even in a temperate one, under favorable circumstances, should be encouraged, there can be but one opinion. And when it is considered that its qualities are able to supersede that of the olive and the almond, which are but precarious in their crops—to which may be added, that as a plant it is greedily devoured in the green state by cattle—how much may it not serve to assist the new settler in regions of the world which have a climate suited to it.