Oil of Orange Flowers (Oleum Naphæ, Oleum Neroli),
commercially known also under the French names huile de fleurs d’oranges, huile néroli, huile néroli pétale, is obtained from the flowers of the orange-tree in Southern France, where the orange is specially planted for this purpose. The odor of the oil varies with the mode of its preparation; that obtained by distillation with water has a different odor from that made by maceration with fat and extraction with alcohol. The latter variety of oil as such, however, is not found in commerce, the alcoholic extract entering at once into the composition of the perfumes.
The French manufacturers of this oil, which is of great importance in perfumery, distinguish several varieties. The most valuable is the oil from the flowers of Citrus vulgaris (or Citrus Bigaradia), the true bitter orange (or Seville orange) tree. This is the so-called néroli bigarade. That called néroli pétale is obtained from the same flowers carefully deprived of their floral envelopes, so that only the petals are subjected to distillation. Much cheaper than these two is the oil of petit grain which is distilled from the leaves and sometimes also unripe fruits of various trees of the Citrus order.
All these oils are among the most delicate; when fresh they are colorless and have a peculiar bitter taste; exposed to light and air they assume a reddish tint and undergo rapid resinification. They should, therefore, be preserved in particularly well-closed vessels in a dark, cool place.
Not to be confounded with these oils is the