The Essp:ntial Oils of the Westehn Australian Eucalvpts. 247 
13.— THE ESSENTIAL OILS OF THE WESTERN 
AUSTRALIAN EUCALYPTS. 
Part VII. 
THE OIL OF EUCALYPTUS EBYTHRONEMA, TURCZ. 
Bv E. M. Watson, Ph. D. 
Read 9th June, 1942 ; published 28th March, 1944. 
EiicoJyptus crythronerna Turez. has been recorded as occurring along the 
Eastern Railway from Tammin to Southern Cross. North of Tammin, it is 
known at Wyalkatchem and Cow'cowing and, farther west and north-west, 
at Wongan Hills and Ballidu. It also occurs soutli of the railway, and the 
material used in this investigation was collected some 10 miles south-east 
of Merredin. 
It is a small tree, 12 to 18 feet high, or a malice with a bulbous stock 
and several erect stems. It grows in clay soil, usually associated -with E. 
saliihris and E. salmonophloia^ either in the malleo association fringing the 
woodland or in the woodland. The leaves are lanceolate, narrow^ lanceolate,, 
or falcate in shape, and are from tw'O inches to four inches long. The colour is a. 
dark and usually lustrous green, the venation of the cineole type and the- 
submarginal vein is removed from the edge. The lamina is copiously dotted, 
with oil glands. The bark is covered wdth a fine white talc-like powder which 
easily rubs off, leaving, in the older parts, a pinkish bark. Because of this; 
white powder on the stem and branches, it is commonly called the ‘‘ white 
mallee.” The wood is dark brown in colour, is very hard and susceptible to- 
termite attack, which, how'ever, is confined to the heart wood. 
The material used was collected by Mr. G. E. Brockw-ay of the ForestS' 
Department, towards the end of August, 1941. It was obtained from mallees 
on Avon Location 20751, about 10 miles south-east of Merredin, and its identity 
was confirmed by Mr. C. A. Gardner, Government Botanist. 
The air-dried terminal branches were steam distilled, the oil coming' 
over very rapidly. It w^as pale yellow in colour and had an irritating odour 
the yield a\’craged from 2*5 to 2-6 per cent, by weight. The physical con- 
stants of the oil are those of a typical cineole oil, and its solubility in alcohol 
shows a low proportion of terpenes. The crude oil itself contains over 70 
per cent, of cineole. whilst the rectified oil contains 80 per cent, of cineole. 
Free acids and esters are present in only small amount, but alcohols, the greater- 
part of which is geraniol, make up more than 13 per cent, of the oil. Both, 
low' and high boiling aldeliydes are present, but in no great quantity. 
The rectified oil, boiling between 164° and 185°, is a very high grade- 
medicinal oil. It makes up over 80 per cent, of the oil, contains, as already 
stated, 80 per cent, of cineole, and (‘omplies wdth all the requirements of the 
British Pharmacopoeia for eucalyptus oil. It is colourless and has a very 
pleasant, non-irritating, camphoraceous odour. 
Although clearing for farming has probably removed appreciable 
quantities of this eucalypt, its commercial exploitation should still be possible.. 
Cultivation shoukl also be economically sound on account of the good yield 
of high grade oil obtainable from it. 
