100 The Philipfjine Jouiital of Science lais 



The figures for the production prior to 1909 have been tabu- 

 lated by Bacon.- They are considered to be unreliable. 



Table I indicates that the foreign sale of ylang-ylang has fallen 

 off and that the average price per kilogram has decreased. The 

 decline is undoubtedly due in part to the competition of other 

 countries, resulting in a diminished demand for second- and 

 third-grade oils. The improved quality and the recent low price 

 of ylang-ylang flowers have also largely eliminated the poorer 

 grades of oil from the local market. 



The chemical constituents and chemical properties of ylang- 

 ylang oil have been the subject of numerous investigations.'' 

 Various attempts have been made to prepare an artificial oil 

 which would displace the true ylang-ylang oil; but on account 

 of the decrease in price of genuine ylang-ylang oil and its real 

 superiority, these attempts have met with very little success. 



Bacon * found that an oil with a low refractive index, low 

 optical rotation, and high ester number is almost certain to be 

 good; while high refractive index, high optical rotation, and low 

 ester number indicate a poorer grade oil. He states that the ester 

 number of first-grade oils is usually 100 or more, the refractive 

 index is rarely over 1.4900 at 30, and the optical rotation varies 

 from —32' to —45°, the latter depending on the proportion of 

 sesquiterpenes present. These constants are given in Table II. 



Table II. — Classification of ylang-ylang oil according to Bacon. 



Constants. 



First firrade. 



Second irrade. 



Ester number 



100 and above 



80 to 100. 

 Above 1.4900. 

 Above —45°. 



Index of refraction . . .. 



1.4900 and below 



—45° and below 







Two years later Bacon reports ' that owing to a reduction in 

 the price of flowers to 7 centavos (3.5 cents United States cur- 

 rency) per kilogram better flowers were obtainable, and because 

 of the adoption of improved methods in distillation, oils having 

 an ester number of from 130 to 150 were common. 



• This Journal, Sec. A (1908), 3, 65. 



■Gal, H., Cotnpt. rend. Acad. sci. (1873), 76, 1482; Fliickiger, Arch d. 

 Pharm. (1881) (3) 18, 24; Reychler, Bull. Soc. chim. Paris (1894), 11. 

 407, 576, and 1045; Dareus, Ibid. (1902), 27, 83; Schimmel & Co., Semi- 

 annual report (October, 1901), 53; D. R. P. (September, 1901), 142, 

 859; Bacon, This Journal, Sec. A (1909), 4, 130; and (1910), 5, 265. 



'This Journal, Sec. A (1908), 3, 65. 



'Ibid. (1910), 5, 265. 



