"The fact that perfumes are absorbed and retained by oils and fats was known in Egypt at an early date, and later to the Greeks and Romans; it was the basis of perfume-making in the ancient world, and it is still the principle of one of the modern methods employed when dealing with certain delicate flower-perfumes. Balanos oil, which is obtained from the seeds of ''Balanitesa egyptiaca'', a tree that at one time grew plentifully in Egypt and is still abundant in the Sudan (where it is called ''heglig''), is a bland odourless oil that does not readily become rancid and is hence very suitable for making perfumes. If balanos oil be warmed with myrrh, the volatile oil of the myrrh is absorbed by the fixed (non-volatile) balanos oil, which in consequence becomes perfumed, and when the extraction is finished, the perfumed balanos oil can be separated from the exhausted and useless residue by pressing."〔Lucas (1937), p. 30.〕