200 A. R. PENFOLD. 
- 
(2) On subjecting a sample of boiling point, 74—75° CO. at 
20 mm. to distillation over sodium at 757 mm., the first 
drops came over at 172° C., one-third of its volume distill- 
ing at 173—175° C., the remaining two-thirds boiling 
between 175 — 182° C., thus showing partial conversion into 
allo-ocimene. 
(3) On reduction with sodium and alcoho! dihydromyrcene 
was obtained in a moderately pure condition possessing 
the following characters: — Boiling point 68° C. at 20 mm. 
optically inactive; specific gravity at +3° C. 0°790; refrac- 
tive index at 20° C. 1°4511. 
(4) The bromide of the above dihydromyrcene was pre- 
pared by dissolving the hydrocarbon in a mixture of one 
part amyl alcohol and two parts ether, as recommended in 
Parry’s “Chemistry of Essential Oils,’? Vol. 11, page 68. 
On recrystallising from boiling alcohol it melted at 88-89°C. 
Determination of Sesquiterpene.—The fractions boiling 
above 120° ©. at 10 mm. were redistilled, finally over 
metallic sodium, but the quantity available did not permit 
of the isolation of the sesquiterpene in anything like a 
condition of purity, with the single exception of the last 
distillation. This was partly accounted for by the presence 
of resinous bodies in the first two lots, which is evident 
from the following table:— 
Refractive 
index at 
20° C. 
26/9/21 136-—140°C.at 5mm. 0:9492(17°C,) —7-3° 1-5008 
18/10/21 127-—140° C.at5mm. 0:9333(18°C.)  —1°6° 1-5018 
24/8/22 1383—135° C.at 10mm. 0°923 (42° C.) —4:25° 1:5040 
Optical 
Boiling Point. Specific Gravity. otation 
The last mentioned is as pure a sample as was possible 
to be obtained. Precisely the same remarks apply here as 
stated under H. virgatus regarding the identification and 
colour reactions of the sesquiterpene isolated therefrom. 
Minor Constituents.—Small quantities of amyl alcohol 
and its acetic and butyric acid esters were separated by 

