Chemistry of Essential Oils

BUTACE.E 417

what in their odour, etc., so that a trained nose can discriminate between
them.
The table on opposite page, covering analysis by Schimmel & Co.,
gives an outline of the differences between the oils of different districts-
during a given season (1908).
Lemon oil contains a considerable number of constituents, of whieh-
the principal is the aldehyde citral, which is present to the extent of from,1
4 to 5*5 per cent., rarely up to 6 per cent. Burgess and Page
1
have
isolated a hydrocarbon, which is interesting as being quite different from
the terpenes so generally found in the citrus oils. It has the following
characters :—

Origin.

Palermo:

S. Agata:

Barcelona:

Messina:

S. Teresa:

Taormina:

Giardini:

Mascali:

Acireale:

Acicatena:

Catania:

Syracuse:

Pressed in

January

February

March

January

February

March

January

February

March

January

February

March

January

February

March

January

February

March

January

February

March

January

February

March

January

February

March

January

February

March

January

February

March

January

February

March

0-8578

0-8590

0-8577

0-8580

0-8583

0-8575

0-8570

0-8580

0-8575

0-8583

0-8586

0-8591

0-8600

0-8607

0*8610

0-8569

0-8572

0-8580

0-8575

0*8589

0-8585

0-8569

0-8574

0-8578

0-8588

0-8583

0-8590

0-8580

0-8586

0-8580

0-8576

0-8580

0-8589

0-8580

0-8583

0-8575

+ 60° 2'

+ 57° 15'

+ 59° 44'

+ 59° 10'

+ 58° 40'

+ 61° 36'

+ 62° 4'

+ 60° 40'

+ 59° 0'

+ 57° 53'

+ 58° 26'

+ 56° 50'

+ 59° 18'

+ 57° 20'

-r 57° 24'

+ 62° 20'

+ 62° 16'

+ 60° 52'

+ 61° 0'

+ 59° 20'

+ 59° 56'

+ 61° 44'

+ 62° 40'

+ 60° 14'

+ 60° 12'

'+ 59° 38'

+ 58° 22'

+ 60° 6'

+ 60° 14'

+ 59° 12'

+ 61° 52'

+ 58° 16'

+ 59° 50'

+ 59° 28'

+ 60° 35'

+ 62° 6'

aDOf

the First

10 per Cent.

+ 57° 42'

+ 55° 10'

+ 56° 40'

+ 56° 8'

+ 55° 50'

+ 58° 12'

+ 58° 30'

+ 57° 50'

+ 54° 24'

+ 52° 24'

+ 53° 88'

-t 53° 30'

+ 58° 0'

+ 54° 50'

+ 54° 36'

+ 60° 40'

+ 59° 26'

+ 59° 10'

+ 8° 4'

+ 56° 40'

+ 56° 48'

+ 58° 40'

+ 59° 18'

+ 56° 4'

+ 57° 24'

+ 56° 20'

+ 55° 0'

+ 56° 28'

+ 58° 0'

+ 56° 24'

+ 59° 20'

+ 5,o° 26'

+ 56° 50'

+ 57° 24'

+ 59° 22'

+ 60° 32'

Residue

on

Evaporation.

2-6 per Cent.

3-0 „

2-6 „

2-8 „

3-6

2-6

2-2 „

2-4

2-8

3-0

3-0

3-2

3-2 „

3-0

2-8 „

2-4

2-7

2-4

2-8

2-8

3-0

2*4

2-8

2-7

2-6

2-2

2-8

3-2

3-5

3-0

2-8

2-6

2-8

2-9

2-8

2-6

(>

j ( n f } ; > t

Citral

5-2 per Cent.

5-4

6-4

6-3

5-5

5-5

5-9

5-7

5-2

6-5

6-0

5-7

7-1

7-2

6-6

5-8

6-0

5-3

5-7

6 0

5-3

4-7

4-4

4-3

6-5

5-6

5-9

4-9

5-1

4-9

5-0

5-4

5-1

6-7

7-0

5-3

t

t

,

r

r

Specific gravity

Optical rotation

Refractive index

Boiling-point

VOL. I.

1

Jour. Chem. Soc., 85 (1904), 1328.

27

0'7257

0°

1-4066 at 15°

023° to 124°