16 ESSENTIAL OILS FROM THE 



fluid, igniting with great difficulty in open vessels, but burning well and 

 with a dense white luminous flame in the lamp. The ironbark tree 

 occurs on barren ranges, and is frequent in the vicinity of the gold-fields. 



Eucalyptus goniocalyx (one of the White Gums). — The yield from the 

 leaves of this tree is not so copious as that from E. amygdalina, although 

 still very considerable ; 100 lbs. of fresh leaves give a product measuring 

 16 ounces. This oil is of a very pale yellow colour, with a pungent 

 penetrating odour, rather disagreeable ; its taste is diffusible, strong, and 

 exceedingly unpleasant. Its specific gravity is 0-918 ; it boils at 306°, 

 after which the mercury rises to 346°. For illuminating purposes this 

 oil is admirably adaped ; it produces a brilliant white flame, superior in 

 intensity and colour to that from the best American kerosene ; its con- 

 sumption in one of these lamps does not cause any smoke or smell. 

 This tree is scattered over the mountain ranges of Victoria, but is not 

 known in Tasmania. It is in some places rather abundant, being found 

 from the Buffalo Ranges to the Mitchell River, in Gipps Land ; also in 

 the district of the Upper Yarra. 



Eucalyptus globulus (Blue Gum). — Two specimens of this volatile 

 oil are shown in the Exhibition ; No. 1 is from the leaves of 

 young trees, and No. 2 from those advanced in growth. The oil cells in 

 the younger leaves are remarkable for their size, but a larger yield of oil 

 is obtainable from those more perfectly matured ; this amounts to 12^ 

 fluid ounces from 100 lbs. of freshly-gathered material. The essential 

 oil from the blue gum must be regarded as one of the most important 

 of this series, on account of its solvent and illuminating properties, and 

 also in consequence of the large demand for blue gum timber, which 

 occasions the felling of many trees of this kind, so that in some localities 

 leaves of the E. globulus, which are utterly wasted at present, are to be had 

 in great abundance. This oil is a thin limpid fluid, of a very pale yellow 

 tint, almost colourless in the case of the sample from the young leaves ; 

 its odour is like that of cajeput, to which all the oils fi'om the Victorian 

 Eucalypti have more or less resemblance. In E. globulus the camphor- 

 like smell predominates ; its taste is not so disagreeable as the preceding, 

 and more cooling and mint-like. 



The specific gravity of this oil is - 9l7 ; it boils more readily than 

 the E. amygdalina' — viz., at 300", the mercury rising only to 350°. The 

 sample from the young leaves differs slightly in these respects. Reduced 

 in temperature to 0° F., it remained clear, and deposited no solid matter. 

 In contact with iodine, this oil acts like amygdalina, and it is equally 

 difficult to ignite in open vessels. In a lamp it gives a dense white 

 flame, superior to kerosene, without smoke or smell. Its solvent capa- 

 bilities are detailed in the following table. It is worthy of remark, that 

 it dissolves grass-tree resin perfectly, in which it differs materially from 

 E. amygdalina. 



