Chemistry of Essential Oils

218. THE CHEMISTKY OF ESSENTIAL OILS

COMPARISON OP THE PHYSICAL PROPERTIES AND THE CHEMICAL COMPOSITION OP
PEPPERMINT OILS DISTILLED FROM THE FRESH LEAVES, FROM THE TOPS,
AND FROM THE ENTIRE FRESH HERB AT THE VARIOUS STAGES OF GROWTH
(continued).

• 
  

DescriptionYear and

of Material.

1910.

Budding stage:

Herb

Leaves

Tops

Flowering stage:

Herb

Leaves

Tops

Fruiting stage:

Herb

Leaves

Tops

Physical Properties.

Colour, Odour and

Taste.

Dark golden; not

fragrant, minty

odour ; slightly bit

ter, pungent, minty

taste

Golden-yellow; faint

not especially

minty odour;

slightly bitter, pun-

gent taste

Golden-yellow; agree-

able, minty odour;

strong, pungent,

bitter, cooling taste

Pale yellow; mild

agreeable odour

fatty, strong, cool-

ing, pungent taste

Pale yellow : strong

minty odo ur;

slightly fatty, bit-

ter, pungent, cool-

ing taste

Pale yellow; frag-

rant, agreeable

odour; fatty, bitter,

pungent, cooling

taste

Yellowish green ;

very fragrant flow-

ery odour; very

bitter, slightly pun-

gent taste

Golden-yellow;

strong minty

odour; bitter, cool-

ing, slightly pun-

Greenish -yellow;

agreeable, flowery

odour; bitter,

slightly pungent,

cooling taste

Specific

Gravity.

3-9155

(^3) -9156

—

3

-9273

•9231

•9242

•9250

—

Rota-

tion,

50 mm.

Tube.

- 12-1

- 13-1

—

- 5-7

- 9 - 4

- 6-5

- 7

—

Refrac-

tion.

1

1-4718

(^1) 1-4710

—

1

1-4820

1-4753

1-4780

1-4712

1-4720

1*4738

Solubil-

ity in

80 per

Cent.

Alcohol.

4

.7

(^4) -6

—

2-66

•7

•8

•8

—

Chemical Composition

(per Cent.).

Free

Acid

cetic).

•86

•90

•13

-03

1-90

1-43

1-14

4-80

3-30

Ester

(Men-

thyl

Ace-

tate).

16-62

19-80

13*44

11-67

22*27

22-98

20^86

43-40

28-29

Menthol.

Free.

43-76

18-79

29-19

30-94

37-83

48-60

12-7

Total

56'85

34-89

39-78

40-13

68-88

66-71

29-14

—

1

At 22° C.

» At 24° C.

(^2) Turbid in 3 volumes or more.
4
Turbid in 4 volumes or more.