ESSENTIAL OILS 



The natural essential oils are the volatile, odoriferous oils 

 obtained from plants. By volatile is meant that if one of these 

 oils is exposed to the air it will gradually evaporate. These 

 volatile oils may occur in the bark, root, leaves, or other parts 

 of the plant, but usually they are most abundant in the fruits 

 or flowers. Many of these essential oils have a pleasant taste 

 and a very fragrant odor, like that of fruits or flowers. They 

 are employed extensively in the manufacture of various sub- 

 stances for which there is a great demand ; as in perfumes, 

 toilet waters, scents (face and sachet powders), and in essences 

 which serve as flavoring materials for confectionery and for 

 beverages like lemonade and liqueurs. They are also used in 

 medicinal preparations to conceal nauseous odors and tastes. 



Perfumes have been in vogue since the earliest times, and 

 records show that the ancient Egyptians introduced perfumes 

 in their religious services. In certain countries vast tracts of 

 land are devoted to the cultivation of flowers from which 

 fragrant perfumes are obtained. In southern France large 

 quantities of various flowers are raised commercially for the 

 production of natural perfumes. In the French Riviera district 

 alone the annual revenue from cultivated flowers such as 

 roses, carnations, and violets, is over ^24,000,000. Roses are 

 cultivated extensively in Bulgaria, while in the Philippines ilang- 

 ilang is grown to a certain extent. In the Philippines there are 

 a number of perfume plants which are the bases of considerable 

 industries in other countries, but which are not so utilized in 

 the Philippines. Among these are patchouli, lemon grass, and 

 vetiver. 



Various methods such as steam-distillation, extraction with 

 fats (preparation of flower pomades), and extraction with vola- 

 tile solvents are used to obtain the perfume oils from flowers. 



As in the case of seed oils, the purity of essential oils is ascer- 

 tained by determining certain essential-oil constants such as 

 the specific gravity, optical rotation, and especially the ester 

 number, as the value of many oils depends largely upon the 

 presence of a quantity of certain esters. The real value of an 

 oil, however, is determined by the exact odor it possesses. This 



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