﻿G CLOVER. 



order to study this matter further I decide to collect samples of resin from 

 single trees, for separate examination. Accordingly I went to the Prov- 

 ince of Tayabas and from different places in that province I gathered 

 seven samples of from one to two kilos each from pili trees differing in 

 size and sex. At the same time leaves taken from these trees were 

 preserved and also fruit where it was possible to obtain it. All the trees 

 appeared to the writer to be of the same species and all the botanical 

 material gathered was assigned by Mr. Merrill to the species already given. 

 The samples were obtained as fresh as possible, considering the fact that 

 the resin must have remained on the_trees for a month or so in order to 

 allow of the production of a good-sized mass. The different samples 

 were well wrapped in palm leaves and were all worked up within four 

 months after being gathered. The results developed by their examination 

 not only confirmed what had been suspected in regard to variation, but 

 showed that in the majority of cases, in each individual sample, a definite 

 terpene of the limonene series occurred in a pure condition. 



In order to obtain larger quantities of these pure terpenes and to 

 extend the results already obtained; also with the hope of isolating one 

 or more of the unknown terpenes of this class, another collecting trip 

 was made and 14 more samples gathered just as in the previous case. All 

 of these latter were worked up within four months after they were 

 collected. As a result of the complete examination of these 21 samples, 

 "it has been possible to isolate the terpenes dextro-limonene, dextro- 

 phellandrene, terpinene and terpinolene in a pure condition and to study 

 the behavior of these substances in a number of ways; to render certain 

 the presence of an unknown terpene in several products; to establish 

 regularities in the occurrence of certain mixtures where the terpene 

 product is not homogeneous ; to isolate in a pure condition from single 

 samples, two of the constituents of the high-boiling portion of the oil 

 and to show the composition of the mixture which constitutes the high- 

 boiling oil obtained from most samples. The high-boiling oil occurring 

 in elemi and which can be most conveniently and completely removed 

 by distillation in vacuo, will be seen to be a mixture of at least three 

 substances. Here also a great variation has been foimd in the different 

 samples but no connection appears to exist between the terpene oil and 

 the corresponding high-boiling one. No connection can be traced be- 

 tween the age or sex of the tree and the constituents of the oil. 



The following relates to the method of procedure followed throughout 

 in working with the resin. It is difficult to remove all of the terpene 

 oil by distillation with steam, and very little of the high-boiling portion 

 goes over except at quite an elevated temperature, because of the increas- 

 ing viscosity of the residue as the oil is removed. It was desired to 

 remove all the terpene oil possible and, in order to prevent any change in 

 the oil, at as low a temperature as could be used. With this end in view 



