X, A, 2 



Gibbs: Modification of Ylang-Ylang Oil 



101 



This improvement in quality has continued as evidenced by 

 the constants compiled from data obtained from the oils examined 

 by this laboratory, and given in Table III. 



Table III. — Yearly average of constants of ylang-ylang oil for 1910-191^. 



Constants. 



Average for— 



1910 



1911 



1912 



191S 



.1914 



Eeter number 



Index of refraction 



114.3 

 1.4918 

 -27.3 



111.0 

 1.4900 

 -25.7 



112.6 



- 1.4876 



-32.4 



122.3 

 1.4925 

 —20.7 



133.2 

 1. 4853 

 -18.9 



Specific rotation 



degrees-- 





" To Ju 



y 1. 1914 











Measured by Bacon's standard, the average for each year 

 tabulated in Table III has shown a rise in quality over the aver- 

 ages for the years preceding it. This advance in quality is 

 indicative of the fact, referred to above, of the improvement 

 made by the adoption of better methods in handling and distilling. 



In the light of the above tabulation I believe the time is 

 opportune for the introduction of a few changes in the standards 

 for the classification of ylang-ylang oil. Therefore I propose 

 the adoption of a table introduced by Doctor Jahrling of the 

 firm of Santos and Jahrling of Manila. Table IV gives these 

 constants as published by Jahrling." 



Table IV. — Classification of ylang-ylang oil according to Jahrling. 



Grade. 



Ester 

 number. 



Index of 

 refrac- 

 tion. 



Specific 

 rotation. 



Soluble in 



alcohol 



of- 



Extra - - 



>145 

 >120 

 >100 

 <100 



< 1.4900 

 <1.4950 



< 1.4990 

 >1. 4990 







<-35 



<-48 

 <-60 

 >— 60 



Per cent. 



80 



90 



90-96 



96 



la 



1 b 



2 — . 









This table really divides what was formerly classed under 

 Class I into three divisions : namely. Extra, la, and lb, depending 

 on the constants shown by the oil. I believe this to be a 

 fair extension of the grading proposed by Bacon, since it makes 

 a distinction among the really high-grade oils and gives the man 

 with an extra-quality oil credit for his efforts. 



Schimmel & Co." state that in their experience the best oils 

 have a range of constants as given in Table V. 



'Rev. gen. chim. (1913), 16, 43. 



'Bericht von Schimmel & Co. (October, 1913), 108. 



