752 Wisconsin Academy of Sciences, Arts, and Letters. 
The Bark Oil of Incense Cedar ( Libocedrus decurrens Torrey.) 1 
The oil has the following constants; d 15 ° 0.8621; n Dl6 ° 1.4716; 
a D 2 o° +1-10; acid No. 0.60; ester No. 3.22; ester No. after acety¬ 
lation 9.53; yield of oil 0.14%. 
Furfural was detected colorimetrically. The oil consisted 
largely of a-pinene, the nitrolpiperidine melting at 117-118°. 
The small amount of oil distilling between 160-168° was exam¬ 
ined for /3-pinene with, negative results. The oil distilling be¬ 
tween 168 -173° gave dipentene dihydrochloride melting at 48- 
49°. The melting point of the dihydrochloride indicates the ab¬ 
sence of sylvestrene. 
The ester fraction was too small for identification of the con¬ 
stituents. “Green oil” was again present in the high boiling 
fractions. 
The oil has the following composition: furfural, trace; a-pinene 
75-85% ; dipentene 5-6% ; ester as bornyl acetate 1% ; free alco¬ 
hol as borneol 2% ; “green oil” 3%. 
The Oleoresin of Digger Pine (Pinus sabiniana Dougl.) 2 
The oleoresin contained 11.4% of oil having the constants: 
d 15 ° 0.6971; n Dl5 ° 1.3903. 
About 95% of the oil distilled between 96.1 and 98.8°. This 
oil consisted of n-heptane as shown by determination of the phy¬ 
sical properties. 
Rabak 3 states that both the oleoresin and rosin are optically 
inactive but this was not found to be true of either substance. 
A 5.58% alcoholic solution of the rosin had the rotation a D2 o 0 
+0.38°. 
All attempts to obtain a crystalline resin acid from the orig¬ 
inal rosin were unsuccessful. At 10 mm. pressure, the rosin 
distilled between 240 and 250° with only slight decomposition. 
The distillate cooled to a hard transparent mass that crystallized 
readily from acetone. The crystals melted at 151-152°. The 
silver salt contained 26.15% of silver showing that the resin 
acid had the formula of abietic acid, C 20 H 30 O 2 , the silver salt 
of which requires 26.37 % silver. 
Resin crystals removed from the original oleoresin by suction 
1 Jour. Ind. Eng. Chem. 8 (1916) 22. 
2 Forest Service—Bulletin 119, p. 18. 
3 Pharm. Bev. 25 (1907) 212. 
