SCIENCE AND INDUSTRY. 
It is not my purpose to expose business chicaneries or trade secrets, 
but these must be subservient to the matter in hand, viz., to show the 
importance of the products to which I refer. 
There are other Australian essential oils that contain citral— 
Hucalyptus staigeriana (the lemon-scented ironbark of Queensland), and 
Leptospermum liversidge: (the lemon-scented teatree)—but not to such 
an extent as the Backhousia citriodora. 
The essential oil of Hucalyptus macarthuri is another product that 
should have an exportable value. The chief constituent of this oil is 
geranyl acetate. From this product can be obtained some very useful 
perfumery substances, such as geraniol and rhodinol; the latter is one 
of the chief constituents of attar of roses. I have eliminated this very 
product, and produced some artificial attar of roses, the odour of which 
experts have been unable to distinguish from that of a living bloom of the 
Balkan oil rose (Rosa damascena trigentipetala), a few bushes of which 
I have growing. Geraniol and rhodinol are usually extracted from 
essential oils that can be and are used in their natural condition for 
perfumery purposes; but these would not be likely to be broken down 
if a supply of oil of Hucalyptus macarthurt were obtainable. It would 
be better economy to break down essential oils that are much less useful 
in their natural state than to derive the higher products from oils 
that already serve a useful purpose as they are. Mucalyptus macarthuri 
is commonly known as Paddy’s River box, or Camden woolly butt, con- 
fined to the counties of Camden and Argyle, New South Wales. Accord- 
ing to Messrs. Smith and Baker, the leaves and branchlets yield 0.112 
per cent. of crude oil, consisting principally of the ester geranyl-acetate. 
The leaves distilled in June, July, and August yield oil of a higher 
ester content, containing less terpenes, the maximum of ester being 
about 75 per cent. ih fe 
Eucalyptus citriodora, known as the “ citron-scented gum,” found 
principally in the north coast district of Queensland, is another of our 
most important eucalyptus oil species. ‘Those who have had experience 
in dealing with the leaves of this variety report a yield of 0.586 per 
cent. of oil, consisting of 80-90 per cent. of the aldehyde citronellal 
©,,H,,O. This aldehyde is easily reduced to the olefinic alcohol 
citronellol C,,H,,O with sodium amalgam or zine dust. Citronellol 
is a very important constituent of attar of rose, and is used largely in 
the manufacture of perfumery. 
My experience in the manufacture of citronellol from essential oil 
of Hucalyptus citriodora convinces me that ordinary care is all that is 
necessary in following out either of the methods usually adopted for the 
separation of aldehydes from essential oils containing them. ‘Technical 
books upon the subject recommend the bisulphite method, and no doubt 
it affords a very direct way of demonstrating qualitative contents; but 
for practical purposes I prefer fractionation under reduced pressure as 
being more economical and satisfactory as regards the conservation ot 
the by-products. I have produced citronella ©,,1,,0, the purity of 
which is proved by the reduction thereof with sodium amalgam to the 
alcohol citronellol C,,H,,O, the odour of which left nothing to be 
‘desired, and on re-distilling the product under reduced pressure, there 
was no residue. to 
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