﻿4 CLOVER. 



was dextro-rotatory and showed a specific gravity of 0.900 and an index of refrac- 

 tion of 1.48592 at 20°. After fractionation, a good quantity of the nitrite of 

 dextro-phellandrene was obtained from that portion boiling below 175°. In the 

 portion boiling from 175° to 180° he isolated a large amount of dipentene tetra- 

 bromide by treating it with bromine in acetic acid. He recommends the use of 

 the oil for the preparation of dipentene derivatives. He points out that the crystal- 

 line hydrochloride obtained by Deville was dipentene dihydrochloride. Wallach 

 detected no other substances in the oil, but states that it contained a good portion 

 of higher-boiling matter which split off water during the distillation. During 

 the rectification of the oil he frequently noted the appearance of fine, needle- 

 like crystals. These he connected with the crystalline constituents of elemi. 

 These crystals will be referred to later in connection with my own results. 



From the data given by Wallaeh it appears that the oil with which he 

 worked was distilled from the resin at a temperature much above 100°, 

 for it will be shown later that Manila elemi contains a good proportion of 

 high-boiling, oxygen-containing' oil, having a higher specific gravity and 

 refractive index than the low-boiling terpene-containing portion. This 

 high-boiling oil is not removed from the resin except at higher temper- 

 atures. The oils worked with by Stenhouse and Deville, as they are 

 described, contained none of this high-boiling oil and were probably 

 removed from the resin at 100°. 



Schimmel & Co., in their semiannual report of October, 1896, publish some 

 observations concerning the higher-boiling portions of elemi oil. They isolated 

 a product most of which pased over from 160° to 161° at 10 millimeters. At 

 ordinary pressure it boiled from 279° to 280°. It was optically inactive and had 

 a specific gravity of 1.043 at 15°. They did not make an analysis. The April, 

 1897, report of the same firm gives the folowing data concerning elemi oil as 

 determined by them : 



Yield of oil from raw material, 15 to 30 per cent. 



Specific gravity at 15°, 0.87 to 0.91. 



Optical rotation, +45°. 



Tschirch and Cremer ° have distilled Manila elemi as well as other varieties 

 of elemi with steam and obtained oils, but the very meager data which they give do 

 not enable one to decide what differences, if any, exist in the different oils. The 

 oil from Manila elemi constituted nearly 20 per cent of the original, soft resin. 

 The major portion of it boiled from 170° to 175°, this distillate showing the 

 remarkably high specific gravity of 0.955, which figure seems almost incredible. 

 Beyond 175° a thicker oil passed over. The fraction from 175° to 210° deposited 

 white, needle-like crystals on standing; these crystals melted at 170°. 



EXPERIMENTAL. 



The following work concerns only the volatile constituents of Manila 

 elemi; that portion consisting of terpenes and sesquiterpenes and their 

 derivatives, which can be removed by distillation from the resin without 

 decomposition of the latter. In a preliminary examination of a sample 

 of elemi sent to the Bureau of Science from outside of Manila, it was 

 found that the low-boiling constituent of the oil obtained therefrom was 



hoc. tit. 



