Chemistry of Essential Oils

404 THE CHEMISTEY OF ESSENTIAL OILS

Spermaceti or stearin will be easily detected, whilst paraffin wax or

the solid constituent of guaiacum wood oil (which is of an alcoholic

nature) are not so easy of detection. As the stearoptene of pure rose oil

consists of hydrocarbons, no fatty acids will be obtained by saponification,

whereas spermaceti and stearin will yield on saponification and decom-

position of the resulting salts with hydrochloric acid, palmitic and

stearic acids respectively, which may be identified by their melting-

points (palmitic acid from 55° to 62°, and stearic acid from 62° to 68°).

Paraffin will be indicated by the more granular structure of its crystals

than that of the normal stearoptene, whilst the solid portion of guaiacum

wood oil consists chiefly of a solid alcohol and will give an acetylation

value which the pure stearoptene will not.

The following tables are given by Schimmel:—

1.

German

Oil,

Miltitz,

1900.

Specific gravity

Rotatory Power

CoDgealing-point

Stearoptene - con-

tent.

Acid Number

Sap. Number

Sap. Number after

Acetylisation

Sap. Number after

Formylation

Calculated from

these figures:—

Total Alcohols

C 10 H 180.

Citronellol in the

Formylation Pro-

duct.

at 40°

0-8372

at 30°

0-8438

at 30°

• 0° 44'

• 29-0'

28-50

°

/0

2-3

4-5

188-7

59-21

60-44 °/ 0

16-49 7O

German

Oil,

Miltitz,

1900.

at 40°

0-8304

at 33°

0-8360

at 33°

• 0° 52'
  
  
  • 30-0°
  
  
  
  

39-97 °

0

10-4

171-14

47-9

54-00 °/ 0

13-34 ° / 0

Bulgarian

Oil

(Kazanlik).

at 30°

0-8566

at 25°

0-8598

at 30°

-2° 20'

+ 20-0°

18-62 °/ 0

0

11-03

216-0

92-9

70-88 ° 0

25-88 °/ 0

Bulgarian

Oil

(Kazanlik).

by Himself.

at 25°

0-8594

at 25°

• 2° 43'

• 20-4°

18-83 7.

2-3

7-0

204-1

96-8

66-27

26-96

5. 
   
   
   
   6. Oil from F'hilippople
      from our Expert.
      Distilled
   
   
   
   

at 25°

0-8634

at 25°

• 2° 58'
  
  
  • 19-6°
  
  
  
  

18-49 7O

0

11-1

214-7

104-0

70-37

28-97

Purchased.

at 25°

0-8614

at 25°

• 2° 36 '
  
  
  • 20-4°
  
  
  
  

20-55 °/ 0

0

10-1

211-0

100-6

68-93

28-03

Values obtained direct in analysing oils free from stearoptene

Spec. Gravity at 15°

Rotatory Power 20°

Sap. Number after

Acetylisation

Sap. Number after

Formylation

Total Alcohol

Citronellol

0-8857

• 0°56'
  271-55

74-70

93-78 %

20-81 7O

0-8886

• 1°2'

261-64

• 81-22
  90-80 7O
  22-63 7O

—

0-8862

• 2° 49'
  255-8
  125-28
  87-04 °/ 0
  34-90 "U

0-8774

• 2° 38'
  254-8

127-4

86-63 7O

35-50 7O

—

—

—

Of the chemistry of oil of roses, although fairly well understood now,
much controversial matter has been written. Eckart^1 states'that a small

(^1) Inaugural Dissertation, Breslau, 1891.