ESSENTIAL OILS OF TWO SPECIES OF HOMORANTHUS. 193 
THE ESSENTIAL OILS or TWO SPECIES or HOMO- 
RANTHUS and THE OCCURRENCE or OCIMENE. 
By A. R. PENFOLD, F.C.S. 
Economic Chemist, Technological Museum, Sydney. 
[Read before the Royal Society of N. S. Wales, November 1, 1922. } 
THE essential oils herein detailed were obtained from the 
leaves and terminal branchlets of Homoranthus virgatus 
and H. fiavescens, both of which were described by Allan 
Ounningham when establishing the genus Homoranthus in 
1840 (Schau. Myrt. Xeroc. 191, t. 3, 1840). Later botanists, 
such as Mueller and Bentham united the two species under 
H. virgatus, considering them to be identical. The botany 
of these interesting Myrtaceous shrubs has been under 
careful observation by Mr. H. Cheel of the National Her- 
barium, Sydney, for some years, with the result that they 
are again separated and considered quite distinct species. 
The botanical description, together with key, distribution, 
and bibliography of both of them is fully described by this 
worker in this Journal, ‘“‘Notes on the genera Darwinia 
Homoranthus and Rylstonea in New South Wales, Queens- 
land, and South Australia,’’ on pages 63, 69, 75-77. 
The examination of the essential oils confirms in a most 
striking manner the individuality of the two species, the 
first named yielding an oil containing up to 80% d-«-pinene, 
and the other the same quantity of ocimene, two bodies of 
entirely different properties and constitution, and bearing 
no relation to one another. The author has also had the 
opportunity of seeing both species in the field, and was 
much impressed by the characteristic habit of H. flavesceius 
M—November 1, 1922, 
