﻿THE TERPENE OILS OF MA ML A ELEMI. 29 



in a dish of water. After four or five hours, the absorption appeared 

 to be nearly complete, but the current of acid was continued for several 

 hours longer. The contents of the flask were then distilled at reduced 

 pressure. After the excess of acid and the carbon disulphide had been 

 removed, the residue was distilled at as low a presure as could be main- 

 tained, considering that hydrochloric acid appeared continually to be 

 given off. The product boiled completely within a range of 15° or 20° ; 

 the distillate contained much terpene and possessed a very strong odor 

 of hydrochloric acid. Phellandrene behaves quite differently from li- 

 monene, and the hydrochloride which appears to be formed at ordinary 

 temperature is decomposed to a large extent by distillation at reduced 

 pressure. 



Action of bromine. — Several investigators have studied the action 

 of bromine upon phellandrene-containing oils and from their work it 

 appears that the substance takes up at once only 2 atoms of bromine to 

 form an oily dibromide. It was desired to ascertain whether this dibro- 

 mide, when produced from pure phellandrene, could be obtained in the 

 crystalline form. 



Three and one-tenth grams of phellandrene, taken from sample XVI. A. purified, 

 Mere dissolved in 3 volumes of carbon tetrachloride and the solution cooled in 

 a freezing mixture; 3.4 grams bromine (2 atoms) dissolved in 3 volumes of the 

 same solvent and cooled were then slowly added to the first solution, which was 

 continuously shaken, while immersed in the freezing-mixture. The color of the 

 bromine disappeared immediately, until nearly all had been added: the last few 

 drops producing a color which remained for over one minute and fumes of 

 hydrobromic acid then appeared. The solution was then evaporated in vacuo 

 for several hours in order completely to remove the solvent. The residue, a 

 quite mobile oil, was allowed to remain in the ice chest for twenty-four hours, 

 but did not crystallize. 



Crystalline auto-oxidation 'product of phellandrene. — It was frequently 

 observed that samples of purified oils on standing deposited a greater or 

 less quantity of crystals upon the walls of the containing vessel. In most 

 cases, even after long standing, the amount of crystalline substance was 

 small in proportion to that of the oil but in several instances about 0.2 

 gram was obtained from 50 to 75 grams of oil. One sample of purified, 

 high-boiling oil, not over 25 grams in amount, deposited nearly 0.5 gram 

 of this crystalline substance soon after distillation. It was later observed 

 that in no case were crystals found in an oil derived from a sample of 

 elemi known not to contain phellandrene. Although at this time some of 

 the oils had been completely used up, it was observed that more or less of 

 the crystalline substance could be found in both the terpene and the bigh- 

 boiling oils on hand, which were derived from phellandrene-containing 

 samples. It seems almost certain that the substance is derived from phel- 

 landrene. In all cases which were studied, the crystals from dilTerent 

 oils were found to be identical. They are moderately soluble in alcohol 



