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cate than that of leaves. For example, the odor of the leaves of a 

 Rose Geranium is due to (/cranial, but the more delicate odor of a 

 rose is due to geraniol plus seven or eight other volatile oils whose 

 odors combine to give the more delicate scent of the flower. 



The essential oils of flowers occur in the epidermal cells of the 

 petals and/or sepals, usually on the upper surface. In the flower- 

 bud it is stored in an inert form— probably as a glucoside (a com- 

 bination of sugar and an essential oil). As the flower opens this 

 glucoside is acted on by an enzyme ( ferment), which breaks down 

 the glucoside and releases the essential oil, thus giving the opening 

 flower its odor. 



The combination of essential oils in lilac flowers lias a very for- 

 bidding name — "three-methyl-valeraldehyde-isopropyl carbinol, with 

 small amounts of phenyl acetaldehyde, phenyl propylaldehyde, and 

 phenyl glycol." Bui this forbidding name describes the chemical 

 basis, as we all know, of a very atractive and popular odor, although 

 the odor of lilacs is not attractive to some people. Some varieties 

 ot lilac have flowers with an odor unpleasant to most people, often 

 resembling the disagreeable odor of the flowers of Privet, another 

 shrub of the same family (the Olive Family) to which the Lilac 

 belongs. (C. .V. (/.) 



The essential oil of lilac is not available as a perfume in com- 

 merce. "A basic formula for a synthetic lilac oil would consist of 

 approximately fifty parts of Terpineol, twenty-five parts of Hy- 

 droxy Citronellol, six parts of Anis Aldehyde, live parts of Helio- 

 tropine, one part of [so Eugenol, two parts of Alpha Amy] Cin- 

 namic Aldehyde, twelve parts of DiMethyl Benzyl Carbinol. two 

 parts of Phenyl .Acetaldehyde, two parts of Anis Alcohol. Besides 

 these, compound oils of Jasmine, Tuberose, Jonquil, Rose, Iris. 

 Orange blossoms, Ylang, Hyacinth, and others, are added in small 

 quantities." (Dr. Ernst Ohlsson. In personal letter.) 



Lilac Colors 



Mrs. McKelvey ( V)2&) gives detailed descriptions of the colors 

 of buds, and of the inside and outside of the flowers of several 

 hundred varieties, according to Ridgway's Color Chart. 



