Myrrh was already in Moses's time an article used in the sacrifices of the Israelites. It seems to have been made use of by Democrates. Dioscorides enumerates eight varieties of it, and Pliny seven, which he obtained from Abyssinia. Herodotus and Diodorus Siculus mention Arabia as the home of the myrrh tree.
In perfumery, myrrh is chiefly used for dentifrices and fumigating pastilles and essences.
_Opopanax_ is the inspissated juice of the root of _Opoponax Chironium, Koch_, or _Ferula Opoponax, L._ It forms grains or lumps of a red-yellow or brown color, and has a fracture of a waxy lustre. It can be rubbed to a gold-yellow powder. It has a strong and peculiar odor, and a very bitter and balsamic taste. With water it forms an emulsion, while it is only partially soluble in spirit of wine. It contains very little volatile oil, and a resin which melts at 212° F., and is soluble in ether and aqueous alkalies. It further contains gum, organic and inorganic salts, and foreign admixtures. Opopanax is but little used in perfumery. For _Extraits_ the opopanax oil is better adapted than the tincture prepared from the gum, the latter coloring the _Extrait_ dark.
_Olibanum or Frankincense_ is the inspissated juice of various varieties of _Boswellia_, partially indigenous to Africa and partially to Asia. The pure pieces are pale yellow, seldom reddish, transparent, or opaque, brittle, covered with a mealy coating and of a splintery fracture. The specific gravity of olibanum is 1.22; its odor is slightly balsamic, and its taste bitter and pungent. It melts only incompletely when exposed to heat, diffusing an agreeable odor. It consists in 100 parts of 5 to 7 parts of a clear volatile oil, boiling at 323.6° F., and of specific gravity 0.86, 56 parts of acid resin, and 30 to 36 parts gum, which corresponds with gum-arabic. With water it forms a milky fluid, and is mostly dissolved by spirit of wine. Selected olibanum (_Olibanum electum_) is the best commercial variety, while _Olibanum naturale_, _O. in lacrymis_, and _O. in sortis_, form darker pieces intermingled with separate paler grains, and contaminated by pieces of bark, and wood and sand.
Olibanum is only adulterated with sandarac and naturally exuded pine resin, inspissated to tears by exposure to the air. The former is recognized by the fracture being glassy and transparent, and the latter by completely dissolving to a clear solution in spirit of wine.