334 BROOKS. 



Michelia champaca L. is a tree of such a size that a man can scarcely 

 encircle the trunk with his aims. This does not appear to be the case in 

 the Philippines. The trees about Manila are usually somewhat smaller 

 than those of ylang-ylang and have trunks which are 20 to 50 centimeters 

 in diameter. The above firm also states : "According to our observations, 

 the perfiune of the flowers of the Philippiae champaca is stronger and 

 sweeter than that of the Singapore, Penang, Colombo, and Peradiniya 

 flowers. It would appear that it is the same with this tree as with the 

 ylang-ylang, which does not yield the same essential oil in Java, the 

 Straits, or Ceylon as in the Philippines.'" 



The Boyal Botanical Gardens at Peradiniya, Ceylon, contain Michelia 

 champaca trees which are from 1 to 1.25 meters in diameter, and Mr. F. 

 A. McMillan, the cuiator, states that he has seen one felled which was 

 at least 2 meters in diameter. Many trees growing at Peradiniya are 

 much larger than those in the Philippines. Ylang-ylang and kapok trees 

 attain fully twice the size tlie}' ordinarily reach in this Archipelago. 



In experimenting with champaca flowers it is essential to work rapidly 

 as after they have been picked a few hours they begin to turn brown 

 and their fragrance is seriously impaired. The rapidity with which this 

 darkening takes place when the flowers are slightly bruised recalls the 

 similar behavior of gardenia flowers, which contain an oxidizing ferment. 



I have found that an oxidizing ferment is present in champaca flowers, 

 and the change in color and deterioration of the fragrance is accompanied 

 by oxidation. However, the development of the color may take place 

 slowly after the enzvme is killed or inhibited by certain poisons. The 

 autoxidation of a chromogen substance evidently occurs. 



An aqueous solution of the oxidase turns tincture of guiacum blue 

 directly and oxidizes certain phenols. The solution turns brown at the 

 surface the instant it is exposed to the air, but previous heating for a 

 few minutes to 100° wiU prevent the coloration. 



It is possible that this oxidase has something to do with the develop- 

 ment of the disagreeable odor in the brown flowers. 



The constants of two specimens of champaca oil recently prepared here 

 are as follows : 



1 





Specific gravity ^. 



Refractive index N ^ 



Ester number 



Ester number after acerylating 



0.904 0.9107 

 1.4640 i 1.468S 

 124 j 146 j 

 199 



