140 THE CHEMISTEY OF ESSENTIAL OILS
The semi-carbazone of the melting-point 126°, heated with dilute sul-
phuric acid, gave the characteristic odour of hydrocirinamic aldehyde.
Cumic aldehyde : C 10 H 12 O.
From the bisulphite liquors from which the double compounds of
the aldehydes mentioned above had separated as solid products, a
small quantity of an aldehyde was obtained which had the odour of
cumic aldehyde. Its semi-carbazone melted at 201° to 202°, and
yielded on combustion values corresponding to those calculated for
the semi-carbazone of cumic aldehyde.
- 0-1481 grm. of the substance yielded 0-1002 grm. H 2 0 and 0-3494 grm. C0 3.
- 0-1475 „ „ „ „ 0-0991 „ „ 0-3457 „
Calculated for CnH 15 ON 3 :— Pound:—
- C 64-39 per cent. 64-35 per cent.; 63-93 per cent.
H 7-32 „ 7-52 „ 7'47 „
- -"The semi-carbazone obtained from cuminol had the same melting-
point ; the mixture of the two products also melted at 201° to 202°.
On oxidation of the aldehyde with moist silver oxide, cumic acid of
the melting-point 114° to 116° was obtained ; a mixture of this acid
with pure cumic acid melted at the same temperature.
Linalol: C 10 H 18 O.
The fractions of the boiling-point 80° to 92° (at 6 to 7 mm. pressure),
freed from aldehydes by bisulphite solution, were rectified in vacuo, and<
the portions distilling at ordinary pressure at 195° to 205°, which had a
distinct linalol-like odour, were oxidised in the cold with chromic acid
mixture. The specific gravity of this fraction was 0*8772, the optical
rotation - 8° 32'. The resulting aldehyde purified by the bisulphite
compound had the odour of citral; when heated with pyruvic acid and
/?-naphthylamine, it yielded citryl-/2-naphthocinchoninic acid of the
melting-point 197°.
Linalyl isobutyrate : C 10 H 17. OCOC 3 H 7.
Linalyl isobutyrate appears also to be present. When saponifying
the fractions boiling between 80° and 111° (at 6 to 7 mm. pressure) and
which had been treated with bisulphite, which on the average gave the
saponification number 20
- 4, there was isolated, in addition to an acid
with a pungent odour (possibly formic acid), another acid with a dis-
tinct odour like St. John's bread. The silver content of its silver salt
did not, however, agree with the value calculated for silver isobutyrate,
which may have been caused by the presence of formate or acetate.
Eugenol: C 10 H 12 O 2.
In order to detect eugenol, " heavy Ceylon cinnamon oil" was
shaken with 2 to 3 per cent, potash solution; the oil separated from
the alkaline solution by acid gave the blue eugenol reaction with ferric
chloride, and yielded with benzoyl chloride and soda solution, benzoyl
eugenol of the melting-point 69° to 70°.
Caryophyllene : C 15 H 24.
This sesquiterpene could be detected in one of the last fractions,
boiling at 104° (at 5 mm. pressure).
- The specific gravity of the portion distilling at 260° to 261° was
0-9047, the rotatory power aD = - T 20'.
Two analyses gave the following values :—
