FRANKINCENSE or OLIBANUM, a gum-resin obtained from certain species of trees of the genus Boswellia, and natural order Burseraceae. Sir George Birdwood distinguishes five species of Boswellia: (A) B. thurifera, Colebr. (B. glabra and B. serrata, Roxb.), indigenous to the mountainous tracts of central India and the Coromandel coast, and B. papyrifera (Plosslea floribunda, Endl.) of Abyssinia, which, though both thuriferous, are not known to yield any of the olibanum of commerce ; and (B) B. Frereana, B. Bhua-Dajiana, and B. Carterii, the "Yegaar," "Mohr Add," and "Mohr Madow" of the Somali country, in East Africa, the last species including a variety, the "Maghrayt d'Sheehaz" of Hadramaut, Arabia, all of which are sources of true frankincense or olibanum. To obtain the frankincense a deep incision is made in the trunk of the tree, and below it a narrow strip of bark 5 in. in length is peeled off. When the milk-like juice ("spuma pinguis," Pliny) which exudes has hardened by exposure to the atmosphere, the incision is deepened. In about three months the resin has at tained the required degree of consistency. The season for gather ing lasts from May until the first rains in September. The large clear globules are scraped off into baskets, and the inferior quality that has run down the tree is collected separately. Much as for merly described by Arrian, in the region of Sakhalites in Arabia (the tract between Ras Makalla and Ras Agab), so now on the sea coast of the Somali country, the frankincense when collected is stored in heaps at various stations. Thence, packed in sheep and goat-skins, in quantities of 20 to 4o lb., it is carried on camels to Berbera, for shipment either to Aden, Makalla and other Arabian ports, or directly to Bombay. At Bombay, like gum acacia, it is assorted, and is then packed for re-exportation to Europe, China and elsewhere. Olibanum is a reputed natural pro duct of China.
Frankincense, or olibanum, occurs in commerce in semi-opaque, round, ovate or oblong tears or irregular lumps, which are covered externally with a white dust, the result of their friction against one another. It has an amorphous internal structure, a dull frac ture ; is of a yellow to yellowish-brown hue, the purer varieties being almost colourless, or possessing a greenish tinge, and has a somewhat bitter aromatic taste, and a balsamic odour, which is developed by heating. Immersed in alcohol it becomes opaque, and with water it yields an emulsion. It contains about 72% of resin soluble in alcohol (Kurbatow) ; a large proportion of gum soluble in water, and apparently identical with gum arabic; and a small quantity of a colourless inflammable essential oil, one of the constituents of which is the body oliben, Frankincense burns with a bright white flame, leaving an ash consisting mainly of calcium carbonate, the remainder being calcium phosphate, and the sulphate, chloride and carbonate of potassium (Braconnot). Good frankincense, Pliny tells us, is recognized by its whiteness, size, brittleness and ready inflammability. That which occurs in globular drops is, he says, termed "male frankincense"; the most esteemed, he further remarks, is in breast-shaped drops, formed each by the union of two tears. The best frankincense, as we learn from Arrian, was formerly exported from the neighbourhood of Cape Elephant in Africa (the modern Ras Fiel) ; and A. von Kremer, in his description of the commerce of the Red Sea (Aegypten, etc., p. 185, ii. Theil, Leipzig, 1863), observes that the African frankincense, called by the Arabs "ash," is of twice the value of the Arabian "luban." Frankincense was used by the ancient Egyptians in their religious rites, but, as Herodotus tells us (ii. 86), not in embalming. It constituted a fourth part of the Jewish incense of the sanctuary (Ex. xxx. 34), and is frequently mentioned in the Pentateuch. With other spices it was stored in a great chamber of the house of God at Jerusalem (I Chron. ix. 29, Neh. xiii. As a medicine it was in former times in high repute. Pliny (Nat. Hist. xxv. 82) mentions it as an antidote to hemlock. Avicenna (ed. Plempii, lib. ii. p. 161, Lovanii, 1658, fol.) recom mends it for tumours, ulcers of the head and ears, affections of the breast, vomiting, dysentery and fevers. In the East frankincense has been found efficacious as an external application on carbuncles, blind boils and gangrenous sores, and as an internal agent is given in gonorrhoea. In China it was an old internal remedy for leprosy and struma, and is accredited with stimulant, tonic, sedative, as tringent and vulnerary properties. It is not used in modern medi cine, being destitute of any special virtues. (See Waring, Pharm. of India, p. 443, etc.; and F. Porter Smith, op. cit., p. 162.) Common frankincense (thus, or abietis resina), is the term ap plied to a resin which exudes from fissures in the bark of the Norway spruce fir, Abies excelsa, D.C. ; when melted in hot water and strained it constitutes "Burgundy pitch," Pix abietina.