(^270) THE CHEMISTEY OF ESSENTIAL OILS
named, the oil contains geraniol, dipentene, one or more terpenes not
identified, and a ketone which is probably thujone. The oil from young
plants contains as much carvacrol as, but less ketones than the oil from
matured plants. The following table gives the character of a number of
oils distilled during 1913-1916.
OILS DISTILLED IN 1913.
No. of
Sample.
1 2 8 4 5 6 7 8 9
10
11
12
13
14
15
16
17
18
19
20
21
22
Oil of
1914
1915
1916Yield
of Oil
Per
Cent.0-314
0-270
0-276
0*442
0-376
0-431
0-426
0-425
0-510
0-432
0-444
0-490
0-522
0-555
0 627
0-720
0-674
0-694
0-540
0-557
0-402
0-555
—
0-578
0-318
Specific
Gravity
of Oil
at 25°.0-9087
0 8960
0-9140
0-9033
0-9026
0-9089
0-9166
0-9239
0-9292
0-9355
0-9284
0-9440
C-9246
0-9290
0 9140
0-9465
0-9239
0-9034
0-9200
0-9340
0-9220
0-8998
0-9180
0-9087
0-9230
Optical Rota-
tion in
100 mm.
Tube.- 5-95
- 3-10
- 4-28
- 3-85
- 3-95
- 2-75
+ 0-25
+ 3-38
+ 0-60
+ 5-20
+ 4-00
+ 4-64
+ 3-70
+ 2-30
+ 12-25
4- 10-05
+ 1-60
- 4-22
- 2-35
+ 11-20
-0-80
Too highly
coloured
+ 0-05
+ 8-05- 1-10
Index of
XjRefraction A-Fi* A A 4" 1 ^V\
ofttb lft 1O -O^0 7? ,1-4962
1-4915
1-4850
1-4905
1-4930
1-4911
1-4894
1-4893
1-4980
1-4913
1-4905
1-4958
1-4910
1-4910
1-4840
1-4940
1-4902
1-4888
1-4995
1-4850
1-49741-4831—
1-4901 at 14-5°
1-5025 at 15°Per
Cent,
of
Phenol.41-4
34-2
21-7
31-0
38-0
32-0
24-0
19-0
38-0
23-0
22-0
29-6
25-0
26-0
14-5
28 0
27-4
28-0
53-0
20-0
42-0
15-0
32-0
23-0
49-0
Per
Cent,
of
Ketone.3-0
7-0
4-0
8-0
3-0
7-5
40-0
8-0
20-0
20*0
12*0
26-0
12-0
30-0
24-0
12-0
5-0
5-0
24-4
3-0
3-0
10-0
15-0
5-0
Acid
No.1-49
3-44
2-15
1-23
1-85
3-57
4-13
7-42
30-85
4-85
41-66
10-99
20-95
1-38
22 86
18-60
0-54
0-60
45-17
5-25
6 01
1-88
0-55
0-72
Ester
No.4-32
17-02
11-31
5-85
7-61
11-00
11-88
15-34
19-20
14-34
27-28
6-09
18-00
6-92
15-46
3-64
7-94
5-04
33-27
17 65
21-21
4-75
3-80
3-75
Saponifi-
cation No.
of Acetyl-
atedOiL166-5
_
193-7
173-8
160-4
167-1
148-7
118-2
165-8
175-2
142-3
158-8
127 0
171-5
85-8
146 7
184-3
180-4
193-1
185-2
195-8
190-7
138-8
110-1
111-6
VERBENACE^E.
OIL OF VERBENA.Most of the commercial so-called verbena oils and verbena extracts
are in reality composed of lemon-grass oil, which has almost entirely
superseded the older and true vervain oil. The genuine oil closely re-
sembles lemon-grass oil in general characteristics, but is of more deli-
cate odour. It contains a large quantity of citral, which, of course,
accounts for its similarity to lemon-grass oil. The plant yielding this oil
appears to be Lippia citriodora (Verbena triphylla : Aloysia citriodora).
The exact character of true verbena oil is somewhat obscure on account
of the almost universal use of lemon-grass oil under this name.