KUTACB^ 439
(1) Two hours' saponification ....... 124
(2) One hour's „ 101'5
Difference 23
- 5
A large quantity of the oil was then repeatedly fractionated under re-
duced pressure. The difference in boiling temperatures of this group of
alcohols and esters is considerably less under very low pressure than at
normal pressure. Attempts to fractionate at normal pressure were suffi-
ciently definite to strongly support the whole of the preceding results,
although the characters of the fractions in question only showed ap-
proximations to those of terpinyl acetate. After a series of fractionations
a fraction was finally obtained boiling at 217° to 221°, which had a clear
and definite odour of terpinyl acetate, and whose specific gravity was
0-917, and refractive index 1*4773 at 20°. A fractional saponification of
this fraction, by the method above described, gave the following results:—
Two hours' saponification ........ 192
One hour's „ 160
Difference 32
By reducing the pressure to about 11 to 14 mm., and collecting the
fractions boiling from 100° to 118° and refractionating three times, a
fraction was obtained boiling at 110° to 115°, which had the following
characters:—
Specific gravity'. .. 0'9205
Eefractive index 1-4781
Saponification value (two hours) ....... 199
„ „ (one hour) 164
Difference 35
Similar fractionations were made with the saponified oil, and fractions
were obtained having a marked odour of terpmeol, although the body
could not be obtained in a pure condition.
Petit-grain oil contains camphene, /?-pinene, dipentene, limonene,
Z-linalol, d-a-terpineol, geraniol, esters of linalol and geraniol, a sesqui-
terpene, and methyl anthranilate.
OIL OF LIMES.
There are three distinct oils found in commerce, the one, hand-pressed
oil obtained from the Citrus limetta (Italian), the others being the dis-
tilled and hand-pressed oils respectively from Citrus medica var. acida
(West Indian). Expressed oil is prepared from the fruit in December
and January. In the south-west of Italy the tree is known as limoncello
di Spagna. The Italian oil somewhat resembles lemon oil, but with a
much richer odour, somewhat recalling the odour of bergamot. It con-
tains pinene, limonene, and probably dipentene, linalol, linalyl acetate,
and citral. It has the following constants :—
Specific gravity 0'872
Optical rotation ..........+ 58°
Saponification value ......... 75
Adulterants such as lemon oil and terpenes are frequently used and
may be detected by distillation tests as given for lemon and orange oils.
Distilled oil of limes, the usual oil of commerce, is obtained from Jamaica,
Dominica, and Tahiti, but chiefly from the island of Montserrat, the