ESSENTIAL OILS. 77 



The most valuable constituent in the oils of these two plants 

 is, of course, geranyl-acetate, and as this has a considerable value 

 (about 30s. per pound when pure), it is worthy of consideration, 

 whether the systematic cultivation of these plants could not be 

 made a successful commercial proposition. In no other plant, so 

 i^r known, has an oil so rich in geranyl-acetate been found. The 

 •oil can be distilled from the leaves of either plant very easily, so 

 that no difficulty whatever should be experienced in this respect. 



As with most species of Eucalyptus the vitality of this tree is 

 most marked, and no ordinary cutting seems to seriously affect 

 the life of the plant. Some time back, in a paddock at Bowral, I 

 saw numerous clumps of "sucker" growth of E. Macarthuri 

 springing from the stumps of trees which had previously been 

 'felled. I was informed that they were repeatedly eaten down by 

 stock, and yet continued to thrive. The yield of oil, too, in this 

 young growth is greater in amount than with the leaves of older 

 trees, and the ester content is larger also. Oil was distilled from 

 " suckers " obtained for me from Paddy's River, by Mr. W. F. 

 Farrell, who collected them in March, from the stumps of trees 

 felled the previous year. The growth of " suckers " was most 

 vigorous and dense. The yield of oil was 0'23 per cent., and the 

 amount of ester 77*5 per cent. ; this result is exceedingly satis- 

 factory and promising. It is probable that the month of January 

 will be found to be the best time of the year in which to collect 

 the seed. 



But little is known at present about the propagation of 

 Darwinia jascicularis, but pruning seems to have little effect 

 upon it, except to cause the grovv^th to be thicker and more foliaceous. 



From the knowledge so far gained, it seems reasonable to 

 suppose that with the systematic cultivation of either one or both 

 of these Myrtaceous plants, Australia could secure the greater 

 portion of the trade in this class of essential oils. The world's 

 demand for geraniol perfumery oils is now somewhat considerable, 

 and their use might be expected to increase considerably if they 

 were less costly : a result to be secured with the distillation of 

 these Australian plants. The output of geranium oils is given by 

 Schimmel and Co. for the year 1909 as about 125,000 pounds. 



2. — Citral Oils. 



Two Australian oils belonging to this group are here con- 

 sidered : — 



{a) Backhousia citriodora. 

 {b) Eucalyptus Staigeriana. 



[a) Backhousia citriodora, the " Sweet Verbena Tree," is a 

 medium-sized tree growing in the Moreton Bay district, and on 

 the North Coast Railway in Queensland, and was plentiful between 

 Brisbane and Gympie. The essential oil obtained from its leaves 

 by steam distillation is of considerable commercial importance, and 

 is richer in Citral than any other known essential oil. The yield 



