Chemistry of Essential Oils

18 THE CHEMISTRY OF ESSENTIAL OILS

Specific gravity at 15° 0-862 to 0-870

Refractive index 1-4680 „ 1-4730

Initial boiling-point 154° „ 155-5°

Distillate under 160° 72 „ 74-5 per cent.

„ 170° 95 ,,97-5 „

Bromine value 1-96 ,, 2-31

Iodine value (Hiibl) 360 , 375

„ (Wijs) 335 , 350

„ , , of last 10 per cent, on distillation (Hiibl) 349 , 369

(Wijs) 350 , 365

Refractive index of 1st 20 per cent.... 1-4700 , 1-4722

„ „ 2nd ,, .... 1-4700 „ 1-4724

„ „ 3rd „ .... 1-4710 „ 1-4735

4th „ .... 1-4710 „ 1-4740

5th ,,.... 1-4780 „ 1-4821

The characters of wood turpentine, and the effect of this and of other
adulterants on thess figures is shown in the foliowing table by the author
(loc. dt.):—

Specific Gravity....

Refractive Index

Initial Boiling-point

Distillate under 160°

., 170°

Bromine Value *.

Iodine Value (Hiibl)

.. (Wijs)

...

...

...

„ of last 10 per cent. (Hiibl).

., „ (Wijs).

Refractive Index of 1st 20 per cent.

2nd „.

3rd „...

4th„.

5th„.

• 
  
  
  
  1. 
     
  
  
  
  

Pure

Americanurpentine.

0-866

1-4720

155°

74°

94°

2-2

372

350

360

355

1-4719

1-4700

1-4712

1-4712

1-4781

(2

Wood

urpentine.

0-873

1-4745

159°

61°

™%

1-46

264

240

251

242

1-4731

1-4730

1-4734

1-4732

1-4842

(3)

J3

>er

cent, eac

L)

and (2).

8"

0-869

1-4737

157°

68°

84°

1-82

321

298

304

298

1-4728

1-4720

1-4722

1-47-21

1-4821

(4)

'etroleum

"

urpentine.

0-808

1-4490

98°

48°

75%

0-05

9 0

8-4

9-0

8-5

1-448

1-419

1-4481

1-4470

1-4495

(5)

ii

ll

s~

0-838

1-4610

99°

62°

82°

1-1

190*5

179

184

177

1-4660

1-4675

1-4721

1-4721

1-4735

As Hertz
1
has shown, the optical rotation of American oil of turpen-
tine is very variable. NM.J
The experiments on the opposite page by the United States Govern-
ment Chemists with the oil from named trees show how widely the
rotation may vary even with the product of the same tree :—

1

Jour. Amer. Chem. Soc., 30, 863.