EUTACE^S 427
orange commonly found in the Manila market is a green, loose-skinned
orange of the mandarin orange type. From the peel the essential oil
was obtained by rubbing under water to disintegrate the oil cells, strain-
ing the liquid through muslin and extracting the squeezed pulp with
petroleum ether. This was then shaken with the watery liquid and
separated. This was repeated three times. The petroleum ether was-
evaporated at a pressure of 12 to 15 mm., at a temperature below 50°,
until all the solvent was expelled. The yield and characters of the oil
in three cases are as follows :—
No.x
2
3Oil from 100
Peels.19-33 grs.
14-0 grs.Specific Gravity.0-8416
0-8620
0-8481
Rotation.+ 58-9°
+ 83-4°
+ 79°
Refractive Ester
Index. Number.1-4560 13
1-470 7
1-468 10
OIL OF TANGERINE ORANGE.
The Tangerine oil of commerce, also known as oil of Mandarin
orange, on account of the custom of presenting the orange in question
to the Mandarins in Japan, is obtained by expression from the peel of
Citrus nobilis (Citrus madurensis). The tree is cultivated in Italy,
Malta, the Azores, and several other places.
The peel of the fruit yields an essential oil with a slight blue-violet
fluorescence, due to the presence of a small quantity of methyl anthra-
nilate. The oil has the following characters :—
Specific gravity 0'854 to 0-859
Optical rotation + 67° „ + 75°
Refractive index 1-4748 „ 1-4778
Non-volatile residue 2 to 4 per cent.
The optical rotation of the first 10 per cent, distilled is about 2° to 3°
higher than that of the original oil.
A Spanish sample of Tangerine oil has been found
1
to have the fol-
lowing characters:—
Specific gravity 0-8665
Refractive index 1-4790
Non-volatile residue 8 per cent.
A number of Mandarin orange oils prepared in Japan have been
examined,^2 but as they appear usually to be prepared by distillation they do-
not always agree in physical characters with Italian oils, nor are they, as.
a rule, nearly so fragrant. These samples had the following characters :—
No.1 2 3 4 5 6 7
Iwvt*. | Optical Rotation.0-8489 + 92° 35'
0-8528 + 73° 36'
0-8541 + 68° 5'
0-8483 + 92° 20'
0-8478i + 90° 56'
0-849 + 90' 35'
0-848 + 94°Optical Rotation
of 1st 10 per Cent.
Distilled.+ 91° 32
+ 66° 10'
+ 60° 48'
(^1) Schimmel's Bericht, October, 1911, 39.
(^2) Schimmel's Report, October, 1914, 21; P. and E.O.R., 5 (1914), 72.