G 
BULLETIN 4:54, U. S. DEPARTMENT OF AGRICULTURE. 
Table IV. — Physical properties and chemical composition of peppermint oil distilled 
from the fresh and from the dry herb at various stages of growth during successive years — 
Continued. 
Physical properties. 
Chemical composition (per 
cent). 
Year and descrip- 
tion of material. 
Rota- 
Solubil- 
-p... ! Ester Menthol. 
Color,odor, a nd« a ste.|P^ 5 5ii : ^^- 
ity in 
80" per 
cent 
alcohol. 
acid KT 1 }" 
.(as «£ 1 
tube, i 
aoelte) -to£). Free - Total 
1909. 
Dry herb: 

Volumes. 
Budding 
Greenish yellow; 
strong minty odor; 
pungent, minty 
taste. 
a0. 9337 
-13.1 
61.4695 
c 1.2 
0.17 
13.26 
36.07 
46.38 
Flowering 
Golden yellow; 
a. 9163 
-13.5 
61. 4695 
(d) 
.16 
12.73 
37.37 
47.44 
minty odor; pun- 
gent . minty, slight- 
ly fatty taste. 
Fruiting 
Yellow; unpleasant ! a. 9344 
minty odor; strong, 
pungent, minty 
taste. 
-8.1 
61.4718 
«1 
.36 
17.68 
34.2 
48.15 
1910. 
Fresh herb: 
Budding 
Bark golden; not i /.9155 
fragrant, minty | 
-12.1 
ol. 4718 
9.7 
.86 
16.62 
43.76 
56.85 
odor; slightly bit- | 
ter,pungent,minty 
taste. 
Flowering 
Pale yellow; mild, 
agreeable odor; fat- 
ty, strong, cooling, 
pungent taste. 
/.9273 
-5.7 
al.4820 
e.6 
.03 
11.67 
30.94 
40.13 
Fruiting 
Yellowish green; 
very fragrant flow- 
ery odor; very bit- 
ter and slightly 
pungent taste. 
/.9250 
— 7 
al.4712 
ft. 8 
1.14 
20.86 
12.7 
29.14 
Dry herb: 
"Budding 
Light golden; herb- 
like, faint, minty 
odor; slightly bit- 
ter,pungent,minty 
taste. 
/.9167 
-11 
al. 4724 
KG 
1.20 
19.80 
39.41 
55.01 
Flowering 
Pale brown; herb- 
al. 4765 
3.20 
30.41 
like odor; pungent 
and cooling taste. 
Fruiting 
Golden yellow; fra- 
grant, pleasant 
/. 9383 
— 3.3 
al.4713 
?. 5 
.56 
20.51 
odor; very bitter 
and slightly pun- 
gent taste. 
1911. 
Fresh herb: 
Budding 
.06 
.20 
12.02 
13. 79 
32.37 
34.11 
41.84 
Flowering 

44.97 
a At 22° C. 
6 At 25° C. 
' Turbid in excess. 
d Turbid in 1 volume absolute alcohol; insoluble 
in SO and 90 per cent alcohol in any proportion. 
e Turbid in 2 volumes or more. 
/At 24° C. 
S Turbid in 4 volumes or more. 
h Turbid in 1§ volumes or more. 
» Turbid in 12 volumes or more. 
Table IV shows that the oils distilled from the fresh herb collected 
at the three stages of growth show only slight differences in their 
general properties — color, odor, and taste. The oils from the flower- 
ing plants show a higher specific gravity and comparatively lower 
rotation than those from the budding and fruiting stages. With 
respect to their solubility in 80 per cent alcohol the several oils vary 
considerably. 
