original herbarium material of Mueller, the "Victorian Apple," the "But But" of 

 Gippsland, and the " Apple " of New South Wales. These two latter represent 

 the same species, possess distinctive characters from the former, and have been 

 given the name of E. Bridgesiana. 



On the same grounds, from E. polyanthcinos, Sch., have been separated 

 E. Fletcher i, R.T.B., E. ovalijolia, R.T.B., and E. Dawsoni, R.T.B., which are 

 all good and distinct species, based on a natural classification. Several similar 

 cases may also be noted in this work. 



We have placed little value upon supposed varieties of Eucalypts morpho- 

 logically determined, because at the best they can only be varieties of varieties, 

 and are thus likely to cause' confusion. After all, the difference between a 

 variety and a species is only one of degree, and much must be left to one's 

 judgment as to how far the division or subdivision is advisable. 



Whatever differences of opinion may be held in regard to the nomen- 

 clature of the species as we now submit them, there can be no doubt as to the 

 particular trees from which the material has been obtained for the research, and 

 this, of course, will be found of the greatest importance both scientifically and 

 economically. 



It is evident that the main object of naming the species is for the purpose 

 of recognition, and any simplification in this directio.n should certainly be 

 considered advantageous. 



As the result of this research it can now be stated what are the special 

 yields of oil and their chemical compositions, and because of the practical 

 constancy of constituents in the oils obtained from identical species, it is also 

 now known what the prospective value of such an oil may be, and it can also 

 be stated with some certainty what is its comparative value. 



The uniformity of results and the regularity of specific characters has 

 enabled some order to be evolved, which is altogether most satisfactory. 



This investigation embraces nearly the whole of the known species in 

 New South Wales, Victoria, Tasmania, and South Australia; a few from 

 Queensland, and about a dozen from Western Australia. It will thus be seen that 

 the oils of most of those species peculiar to the north and north-western portion 

 of the continent yet remain to be determined. 



The botanical systematic portion of this work, the figures and other data 

 illustrating the species, are given because of the importance to be attached to 

 the combined botanical and chemical results, thus leading to a more accurate 

 foundation or scientific basis, upon which to establish this important essential 

 oil industry. 



The investigation of vegetable products on more than the botanical side 

 is becoming characteristic now cf workers in many parts of the world, and we 

 think, that future work on the economics of the Australian flora, should be also 

 conducted by the united efforts of botanist, chemist, physicist, and other 

 workers in cognate sciences, for thus only can be attained a complete know- 

 ledge of any plant and its products. One sees the same line of action being 

 pursued to-day in other fields of natural science, for instance the co-ordination 

 of physics and chemistry, with the result that physical chemistry has ultimately 

 emerged as a definite branch of natural knowledge, and similar instances will 

 readily occur to the reader. 



Botanical material of all the species from which oil has been extracted 

 is preserved for future reference, should any doubt arise as to the specific origin 

 of any of the essential oils. 



