ESSENTIAL OILS. 85 



oils, somewhat small, about 0'8 per cent, in the former and about 

 0-7 per cent, in the latter. Both trees belong to the " Stringybark " 

 group, and grow to a large size, so that to make the distillation of 

 turpentine from them in any way commercial^ possible, it would 

 be necessary to cultivate them. Whether the article could then be 

 produced to compete with ordinary turpentine at its present price 

 is a question which yet remains to be settled, but the problem is one 

 certainly worthy of serious investigation.^ 



7. — M ethyl- eugenol Oils. 



An example of a Myrtaceous oil of this class, and one worthy 

 of consideration, is that of Melaleuca bracteata. This is a small tree 

 or shrub growing in the Warialda and other districts of this State, 

 the Museum material being obtained from Oakey Creek. Its 

 botanical features have no marked characteristics by which its 

 remarkable chemical constituents might be suggested, as it closely 

 approaches in some respects M. styphelioides, and has been pre- 

 viously associated with that plant and also with M. genistifolia. 

 It has. however, a remarkably hard and close bark, which seems to 

 separate it at once from the other Melaleucas. A paper on this 

 species was read before the Royal Society N.S.W., Dec, 1910, 

 where the full results of the botanical and chemical investigations 

 are recorded. The constiutents of the oil of this species are quite 

 foreign to those generally found in Melaleuca oils. The principal 

 constituent is methyl-eugenol, of which the oil largely consists. 

 This substance was recently shewn to be the chief odoriferous con- 

 stituent in the timber of " Huon Pine," of Tasmania, Dacrydium 

 Franklinirhni for any possible commercial use to which, in the future, 

 this constituent may be put the supplies could probably be ob- 

 tained from this species of Melaleuca more cheaph' and in larger 

 quantity than from any other source. 



Although perhaps at present there is no great demand for 

 methyl-eugenol, yet synthetic chemistry moves along so rapidly 

 that at any time a request for it might arise, so that it is well to 

 be informed from what source it is obtainable. It would not be 

 possible to prepare it from Eugenol, in the ordinary way, to com- 

 pete with the product from this Melaleuca, so that when the demand 

 does arise Australia is ready to supply it. 



Eugenol is present in small quantity in the oil of M. bracteata, 

 as is also free cinnamic acid and cinnamic aldehyde. An ester of 

 cinnamic acid is also present, but no acid of the fatty series could 

 be detected, nor was any low boihng alcohol found. The slight 

 laevorotation of the oil was due io the presence of la&vorotatory 

 phellandrene. Cineol (Eucalyptol) was quite absent. 



Three samples of oil were investigated from material collected 

 at various times of the year. These gave the following results : — 

 Specific gravity at 18°C. = 1-032 to 1-0358 ; optical rotation «„, 



1 For further results, see papers in Proc. Roy. Soc, N.S.W., Oct., 1898, and Nov., 1911. 



2 " Research on the Pines of Australia," June, 1910, p. 406. 



