pharmacy, a gummy resin, the product of the juniperus lycia (Lin.), brought from Turkey and the East Indies, usually in drops or tears like those of mastic, but larger; of a pale yellowish, and sometimes reddish, colour; a moderately warm pungent taste, and a strong, not very agreeable smell. This drug has received many different appellations, according to its different appearances: the fine tears are called simply olibanum, or thus; when two are joined together, they have been called thus mycolum, and when very large, thus farninimum: sometimes four or five, about the bigness of filberts, are found adhering to a piece of the bark of the tree which they exuded from; these have been named thus corticisum: the finer powder which rubs off from the tears in the carriage, mica thuris; and the coarser powder, manna thuris. This drug is not however, in any of its states, what is now called thus or frankincense in the shops. See the article Thus.

Olibanum consists of about equal parts of a gummy and resinous substance; the first soluble in water, the other in rectified spirit. With regard to its virtues, abundance have been attributed to it, particularly in disorders of the head and breast, in haemoptysis, and in alvine and uterine fluxes: but its real effects in these cases are far from answering the promises of the recommenders. Riverius is said to have had large experience of the good effects of this drug in pleuritis, especially epidemic ones: he directs a scooped apple to be filled with a dram of olibanum, then covered and roasted under the ashes; this is to be taken for a dose, three ounces of carduus water after it, and the patient covered up warm in bed; in a short time, he says, either a plentiful sweat, or a gentle diarrhoea, ensues, which carry off the disease. Geoffroy informs us, that he has frequently made use of this medicine after venefication, with good success; but acknowledges that it has sometimes failed.

Oligædra, in natural history, the name of a genus of crystals composed of very few planes, as the name expresses. The word is compounded of ὀλίγος "a few,"