AUSTRALIAN MELALEUCAS AND THEIR ESSENTIAL OILS. 117 
The knowledge concerning the chemical composition of 
oil of ‘‘cajuput’’? is now somewhat complete, and during 
recent years chemists have devoted considerable effort 
towards the elucidation of this problem. This question is 
more fully considered in Part V of this series of papers on 
the Australian Melaleucas and their oils, and an analysis 
given of a sample of oil of “‘cajuput,’’ sent to us by Dr. M. 
Treub of the Royal Botanic Gardens, Buitenzorg, Java, 
(This Journal, 1913). 
The elementary composition of the principal constituent 
in “‘cajuput”’ oil of commerce was correctly recorded as 
C1oH:s0 by Blanchet as early as 1833 (Annalen 7, p. 161). 
It was named cajuputene hydrate by Schmid] (Journ. Chem. 
Soc. 14, 1862, p. 63). Dr. Gladstone named it cajuputol 
(Journ. Chem. Soc. 25, 1872, p.1). Its identity with cineol 
was shown by Wallach, (Ann. 225, 1884, p. 315). 
‘““Cajuput’’? of commerce is essentially a heavy oil, the 
specific gravity mostly ranging between 0°92 and 0°93; it 
is usually slightly leevorotatory, and contains an excess of 
50 per cent. of cineol when determined by the phosphoric 
acid method. In addition to the cineol the aromatic 
alcohol terpineol is present in small amount, while the 
terpene pinene appears to be the leevorotatory form. 
Although the oil of Melaleuca ericifolia contains both 
cineol and terpineol—the latter in the dextrorotatory form, 
yet, it can replace in no way the “‘cajuput”’ oil of commerce 
for pharmaceutical purposes, as the amount of cineol in the 
crude oil is less than 10 per cent., and the excess of terpenes, 
consisting of dextrorotatory pinene and dextrorotatory 
limonene, causes the specific gravity to be far too low for 
it to conform to official requirements for “‘cajuput.’’ The 
somewhat large amount of terpineol which it contains 
gives to ita much more aromatic odour than possesses that 
of “‘cajuput,’’ and in consequence it may be considered more 
