﻿THE TERPENE OILS OF MANILA ELEMI. 37 



odor and is perfectly miscible with all the solvents. It redistilled from 

 275° to 279° at ordinary pressure, with the formatidh of water. 



The other oils are all more or less yellow in color. Because of the 

 great viscosity of the oils in the lower part of the series and also because 

 of their lack of optical activity, it seems certain that the sesquiterpene 

 derivative contained in them is quite different from the optically active 

 substance XII,B, purified. 



AMYRIN. 



The crystalline residue obtained from elemi by treating it with alcohol 

 has been worked with by many chemists and has long been known as amy- 

 rin. Banp, 27 who appears to have employed Manila-eZe/ni in his work, 

 gives 174° as the melting point of the substance. Vesterberg 2S who also 

 used Manila-eZemt was unable to obtain a constant melting point and 

 showed that the substance is a mixture of two very similar bodies, which 

 were separated by means of their acetyl derivatives; these bodies are 

 o-amyrin, melting point 180° to 181°, and /8-amyrin, melting point 

 193° to 194°. Tschirch and Cremer give 170° to 171° as the melting 

 point of amyrin from Manila-eZewn, after repeated crystallization. 



I wished to note if there was any variation in the amyrin obtained 

 from individual samples of elemi; it was thought that possibly a-amyrin 

 or /3 -amyrin might be found in a pure condition, when derived from the 

 resin of a single tree. 



Two samples, VIII, from which had been isolated pure limonene, and 

 XVIII, which had yielded almost pure phellandrene, were examined. 

 In neither case could a body of constant and sharp melting point be ob- 

 tained; the products resulting from several recrystallizations behaved as 

 mixtures, although compartively, they melted at about the same tem- 

 perature. 



CHANGES IN THE RESIN ON STANDING. 



Portions of three of the samples of resin used in this work were 

 allowed to stand for about fifteen months in covered jars, at the end of 

 which time they were still moderately soft. 



(1) Sample IV yielded much less terpene oil when heated to 150° than it 

 had formerly. The oil, after having been purified in the usual manner, distilled 

 almost completely from 82° to 84° at 38.5 millimeters, this being the same as 

 the boiling point of the pure oil isolated from this sample fifteen months before. 

 Essentially it had undergone considerable change. Its physical constants are given 

 in comparison with those of IV,A, purified, previously isolated. The oil obtained 

 from the old resin when treated with nitrous acid, yielded only a very small 



"Jahresl. f. Chem. (1851), 528. 



™Ber d. chem. Ges. (1887), 20, 1243; (1890), 23, 3187. 



