DESTRUCTIVE DISTILLATION OF MANILA COPAL. 207 



The fraction boiling between 164° and 166° was tested for /3 pinene by oxidizing 

 with alkaline permanganate in the cold. 1 " From a sample weighing 30 grams only 

 a very small quantity, about 0.5 gram, of nopinie acid was isolated, which after 

 recrystallizing from ligroin melted at 124° to 125.° About 15 grams of the oil 

 was unacted upon and was recovered. This was again treated with alkaline 

 permanganate and a small quantity of nopinie acid again obtained. 



The fraction boiling from 165° to 170° was tested for phellandrene, but with 

 negative result. 



The fraction boiling from 170° to 180° was also examined for sylvestrene by 

 testing for its color reaction with acetic anhydride and a few drops of sulphuric 

 acid. The result was negative. An attempt to isolate sylvestrene hydrochloride 

 from the hydrochlorides of the hydrocarbons in this fraction also gave negative 

 results. r 



No limonene tetrabromide could be isolated from the fractions of any 

 of the distillates boiling from 170° to '180° and taken from samples 

 yielding 10 per cent or more of terpenes. 14 Limonene was found only 

 in the distillates from samples yielding from 2 to 3 per cent of volatile 

 oil. I hardly feel warranted in advancing any explanation of these facts. 

 Dr. F. W. Foxworthy, 15 of the section of botany, biological laboratory, 

 Bureau of Science, is convinced that almaciga resin is produced by one 

 species of tree only. Whether certain individual trees of this species 

 produce limonene and others do not, as was found to be the case with 

 Manila elemi, 10 has not been determined. Wallach 17 believes that limo- 

 nene is formed in the plant from pinene in the presence of acids. This 

 question may be taken up more fully at a later date. 



THE GASES GIVEN OFE BY MANILA COPAL DURING DISTILLATION. 



The gas given off by the copal during fusion was collected and analyzed. 

 The carbon dioxide in the gas was determined quantitatively at intervals 

 during the distillation. Below 330° the percentage of carbon dioxide 

 remained practically constant at 92.6 per cent, as was demonstrated by 

 repeated analyses. When the temperature had reached 330° the change 

 in the nature of the decomposition was shown by the difference in the 

 composition of the escaping gas. Beginning at this point, gas analyses 

 made at intervals of ten minutes showed the following results: 



13 Baeyer and Villiger. Ber. d. ilcutschen chem. Ges, ( 1896) , 29, 22. Schimmel 

 & Co., Rep. (1908), April, 103. 



14 The only terpene positively identified in these fractions was dipentene. The 

 fractions were brominated as for limonene and the solutions placed in an ice box 

 for four days. Only very small yields of crystals were obtained, which, after 

 recrystallizing from alcohol and ether, melted at 120°. 



"This Journal, Sec. A (1910), 5, 



16 Clover, This Journal, Sec. A ( 1907) , 2, 1 ; Bacon. This Journal. Set: A ( 1909 I . 

 4, 93. 



17 Ann. d. Chem. (Lieoig) (1888), 246, 235. 



