16 H. G. SMITH. 
botanical differences which Mueller saw are now shown to 
be distinctive. The essential oils obtained from the leaves 
by steam distillation are alone sufficient for the purpose, 
as these are distinctly different in the two trees, that from 
M. genistifolia has no possible commercial value, as it con- 
sists very largely of pinene, between 80 and 90 per cent. 
of the oil being that constituent, and it does not appear to 
contain in any degree the characteristic constituent of the 
oil of the other species. The oil of M. bracteata consists 
very largely of methyl-eugenol—a constituent heavier than 
water—while the very small amount of terpene present is 
pbellandrene. The oil also contains a small amount of an 
ester of cinnamic acid, a little cinnamic aldehyde, and some 
eugenol. None of these constituents occur in the oil of 
M. genistifolia. Surely these two plants must be distinct. 
The yield from M. bracteata is about one per cent., so that 
it produces an oil containing methyl-eugenol in larger 
amount than is obtainable from the leaves of any other 
known plant. Since the first results were published the 
Technological Museum has received material of M. brac- 
teata from Kinbombi in Queensland, hundreds of miles from 
the previous locality. The oil from this material was 
identical in character with that from New South Wales, 
showing the constant nature of this chemical character. 
If the time ever came when it might be desirable to culti- 
vate M. bracteata for its oil, it would not do to substitute 
M. genistifolia, the closely agreeing botanical characters 
notwithstanding. wit , 
The correct position of M. trichostachya with that of 
M. linariifolia has also been decided in a similar manner. 
The leaf oil of M. trichostachya is rich in cineol and the 
species may thus eventually be of some commercial import- | 
ance, but M. linariifolia has no economic value in a like 
direction. 
