ESSENTIAL OILS FROM THE GENERA EUCALYPTUS, ETC. 11 



railway, street carriages, and our hats with it ; and as to our books, 

 if they are not covered with it they ought to be. Truly our progress in 

 art and science is defying all prediction as to what we may not accom- 

 plish, and rendering obsolete many of our familiar proverbs, and none 

 more strikingly so than that " there is nothing like leather." — ' Mechanics' 

 Magazine.' 



ESSENTIAL OILS FROM THE GENERA EUCALYPTUS AND 

 MELALEUCA, SUITABLE FOR GENERAL APPLICATION IN 

 THE ARTS. 



These oils, consisting of nineteen varieties, have properties which fit 

 them for the manufacture of varnishes and for illuminating purposes, 

 and the trees and shrubs from which they are derived are so widely dis- 

 tributed, and obtainable in such quantities, as to render it probable that 

 the oils can be produced at a cost enabling them to compete commer- 

 cially with similar products of other countries. 



Eucalyptus amygdalina (Tasmanian Peppermint, Dandenong Bastard 

 Peppermint). — The tree, from the leaves of which this oil is obtained, 

 occurs chiefly in the southern districts of the Colony of Victoria, and is 

 common in Tasmania ; it occupies open and undulating forest land, and 

 s always interspersed with other trees, and is one of the least valuable 

 of the Eucalypti, considered in reference to its timber. On the other 

 hand, its yield of essential oil is astonishingly plentiful, 100 lbs. of the 

 freshly-gathered leaves, inclusive of the small branchlets to which they 

 are attached, giving upwards of three pints, imperial measure. The oil 

 exists ready formed in the leaf, and the cells containing it may be seen in 

 great numbers on examination by transmitted light. 



This oil is a thin transparent fluid of a pale yellow colour, possessed 

 of a pungent odour, resembling that of oil of lemons, but coarser and 

 stronger ; its taste is rather mild and cooling, producing an after sensa- 

 tion in the mouth resembling camphor, with something of its bitterness. 

 Its specific gravity at 60° F. is 0-881. It boils freely at 330 Q ; but as the 

 evaporation proceeds, the mercury rises rapidly to 370°, where it remains 

 almost stationary. Cooled to 0° F., it at first becomes turbid, and then 

 clearing, deposits a white floccrdent substance, which melts at + 27° F. 

 Suffered to evaporate spontaneously, it proves to be somewhat less 

 volatile than oil of turpentine. Like other essential oils, it leaves no 

 stain on paper, and in shallow vessels it absorbs oxygen, giving rise to a 

 residual resinous matter. When brought in contact with iodine no ex- 

 plosion ensues, even when the temperature is raised ; but a dark-coloured 

 solution is created, which, when heated, emits peculiar variegated 



