COMPOSITE 295
OILS OF ACHILLEA.
Achillea millefolium is an aromatic plant known as Millfoil whose
leaves yield about 0*2 per cent, of essential oil, of a deep blue colour. It
has been examined by several chemists, the results recorded differing
according to the locality of origin of the plant. The majority of pure
samples have the following characters:—
Specific gravity 0-900 to 0'927
Optical rotation - 1° „ - 3°
Ester value 20 „ 38
„ „ (after acetylation) 65 „ 84
Sievers
J
has recorded American oils whose specific gravity varied
from 0-869 to 0*8935.
The oil has recently been very exhaustively investigated by E. E.
Miller.
2
A number of samples distilled from the plant grown near
Madison in various stages of development were found to have the
following characters:—No.1 2 3 4 5 6 7 8 9
1ft
10(^1112)
J.3
14
Place of Collection.
Sunset Point
Highlands.
Hammersley Farm
»» »
»»1 *>
» »»
Piper Farm.
Condition.
Dry
Fresh
Hammersley Farm (Flower
Heads only)
Hammersley Farm (Stems
and Leaves of No. 8)
Med. Herb Garden
Sheboygan Co.
Dry
Fresh
—
Dry
Dry
Dry
Yield
Per Cent.
0-164
0-212
0-125
0-111
0-123
0-111
0-213
0-85
0-067
.., „
—
—
Specific Gravity
at 25°.0-902
0-893
0-9035
0-908
0-9038
0-9098
0-8966
0-9055
—
0-9087
—
0-8926
Refractive
Index
at 19-6°.1-4740
1-4718
1-4885
1-4880
1-4855
1-4890
1-4765
1-4875
1-4850
—
—
The results of Miller's investigation may be summarised asfol.ows:—
(1) That a blue oil may be obtained from either the leaves or the
flower heads; most oil is obtained from the latter portion of the plant.
(2) That it would not be profitable to distil the lower two-thirds of
the plant.
(3) That the blue compound may be obtained from very young plants,
though in very small amount.
(4) That drying the plant material apparently produces no change in
either the quantity or the quality of the oil.
(5) That the oil contains the following constituents, Z-a-pinene, d-a
pinene, Mimonene, Z-borneol, bornyl acetate and other esters of borneol,
Z-camphor, cineol, salicylic acid, aldehydes, formic, acetic, butyric (?) and
isovaleric acids, a non-volatile acid or lactone, and a blue constituent of
high boiling-point.
Achillea coronopifolia, according to Willdenow, yields an oil of deep
blue colour and specific gravity -924 with a strong odour of tansy.
lPharm. Rev., 25 (1907), 215. 2
Bull. Univ. Wisconsin, 785.