GENERA EUCALYPTUS AND MELALEUCA. 21 



rated to about one-fourth, its bulk, almost gelatinised when reduced to 

 zero, without losing its transparency. This oil burns very well. 



The red gum has a wider range than any other of the Australian 

 timber trees, being equally common within and beyond the tropics, and 

 is usually found on the banks of rivers ; it does not occur in Tasmania. 



Eucalyptus viminalis (Manna Gum). — A pale yellowish-green oil, the 

 smell of which is disagreeable, but not very strong or penetrating. In 

 taste it resembles odorata. Its specific gravity is 0921, and its boiling 

 points 318° and 360°. The yield is the least of any, being only 5} 

 drachms from 100 lbs. fresh leaves. It burns very well in a lamp. 



This Eucalyptus is to be met with on grassy reaches, often interspersed 

 with odorata ; it is found also in New South Wales, South Australia, and 

 Tasmania. 



Melaleuca linarifolia. — The extraordinary large yield of oil which 

 the leaves of this shrub supply, as compared with the quantities obtain- 

 able from others of the tea-tree genus, naturally places it at the head of 

 the list ; 100 lbs. of fresh branchlets and leaves giving a product measuring 

 28 fluid ounces. It presents the appearance of a very light straw- 

 coloured mobile fluid, of rather a pleasant odour resembling the oil of 

 cajeput, but less aromatic and pungent, and possessed of a singularly 

 agreeable taste — in which respect it differs from most of the other oils — 

 strongly suggestive of both mace and nutmeg, followed by the usual 

 mint-like aftertaste, common in a greater or less degree to the mrytaceous 

 oils. The specific gravity of the liquid under consideration is 0'903, the 

 lower of its two boiling points is unusually high, being 348°, while 

 the interval between it and the temperature at which the mercury ceases 

 to rise, is very much narrower than the average, comprising only 21°. 



This essential oil burns well in the lamp, as far as colour is con- 

 cerned, but its illuminating powers appear to be slightly inferior to 

 good kerosene. This shrub is restricted to East Gipps Land and New 

 South Wales, where it forms large bushes along some of the rivers. 



Melaleuca curvifolia. — The product obtained from the distillation of 

 the leaves and branchlets of this plant is of an oily consistency, and 

 amber colour ; and, like E. Woollsii, leaves a transparent stain on paper, 

 which peculiarity is probably due to a similar cause. Its specific 

 gravity is considerable, being - 938 ; it boils at 364° and 508°, which are 

 remarkably high, being each of them upwards of 40° above the average 

 boiling points of the eucalyptine oils, thus maintaining its similarity 

 to the E. Woollsii. The yield from 100 lbs. freshly-gathered material 

 is 5 ounces 7^ drachms. The taste of this oil is not disagreeable, and 

 resembles cajuput very closely. It is a good solvent for resins. 



This species of tea-tree is found on the coast of Victoria, where it 

 sometimes forms fine umbrageous trees ; it also grows in desert regions, 

 where it is of a scrubby habit. It seems to prefer a saline soil. 



Melaleuca erisifolia (Common Tea-tree of the Colonists). — The shrub 



