GENERA EUCALYPTUS AND MELALEUCA. 15 



in search of them ; and this supply could be maintained from day to day, 

 as required for distillation, almost without limit. 



Besides the favourable influence which the shrubby character of this 

 plant exerts upon the cost of the raw material, the manufacturer of this 

 oil upon a large scale would derive great benefit from the water-carriage 

 which the River Murray furnishes for the transport of produce, and the 

 constant and peculiarly abundant supply of water indispensable for pur- 

 poses connected with the distillation and refrigeration of the oil. 



The Eiver Murray, in Victoria alone, is for about 270 miles of its 

 course covered on its southern bank with Mallee Scrub, receding in some 

 cases to a short distance inland, whilst in others it comes down to the 

 water's edge. Under conditions so favourable, it is certain that the oil 

 can be produced at a very inconsiderable cost. 



The physical and chemical properties of the essential oil of E. oleosa, 

 do not differ materially from the preceding. It is a thin mobile liquid 

 of a pale yellow colour ; mild in taste as compared with others of this 

 class, the flavour being camphoraceous, and also suggestive of oil of tur- 

 pentine in a slight degree. 



Its odour, which is distinctly mint-like, is not so agreeable as that of 

 E. amygdalina. The yield of the shrub, though inferior to that of the 

 Dandenog Peppermint is still very large, 100 lbs. of the green leaves and 

 branches giving 20 ounces of oil. Its specific gravity is - 911, and it 

 boils freely at 320°, and temperature gradually increasing until it 

 remains stationary at 350°. 



Burned in a kerosene lamp, this volatile fluid produces a fine luminous 

 flame, superior in colour to that emitted by the preceding oil under 

 similar circumstances, and totally devoid of smoke or smell. It is an 

 excellent solvent for resins, but accurate determinations of the quantities 

 of such substances taken up by it have not been made. 



Its habitat extends from the Murray to the south of Lake Hindmarsh, 

 and to Spencer and St. Vincent's Gulfs, in South Australia ; it also 

 occurs in the vicinity of Lake Torrens, and in the neighbourhood of the 

 Darling and Murrumbiclgee. It is essentially a desert species, and is not 

 found in Tasmania. 



Eucalyptus sideroxlyon (Ironbark). — In productiveness this tree ranks 

 next in the series, 16 ounces 7 drachms having been obtained from 

 100 lbs. of the leaves alone. This amount should be taken as only 

 approximate, for the green material, closely packed, having to be trans- 

 ported for a considerable distance, had suffered fermentation, and, owing 

 to the heat evolved, to an extent certain to have acted disadvantageously 

 upon the yield of oil. 



The specific gravity of iron bark oil is 0.923 ; it boils at 310°, the 

 mercury afterwards rising to 352°. In taste and smell it closely re- 

 sembles that from mallee scrub. It is a thin, limpid, very pale yellow 



