AND THEIR ESSENTIAL OILS. 23 



EUCALYPTUS MUELLERI, T. B. Moore. 



(" Brown Gum." ) 



BOTANY. 



Historical. This tree was first brought under the notice 

 of Baron von Mueller by Mr. T. B. Moore, who was 

 anxious to dedicate a species of Eucalyptus to the then 

 Victorian Government Botanist. 



Remarks. From the correspondence now at the Mel- 

 bourne Herbarium, which we have been able to peruse 

 through the kindness of Professor Ewart, it is shown that 

 Baron von Mueller always hesitated to name this species as 

 distinct from E ' . vernicosa. 



There can be no doubt that the two are allied, but E. 

 vernicosa is a dwarf tree, whilst E. Muelleri is a very fine 

 specimen of the Tasmanian forests, and yields a first-class 

 hardwood timber in addition to a eucalyptol oil in its 

 leaves. 



Its economies thus outweigh those of its congener E. 

 vernicosa, which cannot be ranked as a timber tree, and 

 thus for commercial reasons alone we think the two should 

 remain as separate species. We have seen no intermediate 

 forms between the two. 



Timber. The timber was pronounced by Mr. Moore, its 

 discoverer, as extremely hard, close-grained, tough, and 

 heavy, and suitable for heavy construction work as well as 

 furniture, and in this we concur. 



CHEMISTRY. 



Essential Oil. Material of this species was obtained 

 from Mt. Wellington, at an altitude of about 3000 feet. 

 It was collected in July, 1908. The principal constituent 

 in the oil of this species is eucalyptol, accompanied with a 

 fairly large amount of pinene. Phellandrene was not 

 present, nor was it to be expected, judging from the 

 botanical features of the species. There was rather a large 

 amount of ester for oils of this class, and this appeared to 

 be largely geranyl-acetate, as it was mostly saponified in the 

 cold with two hours' contact. The crude oil was of a light- 

 amber colour, and had an odour resembling the oils of the 

 group of which E. Smithii may be considered the type; 

 the usual amount of volatile aldehydes was present, but 

 these were separated without difficulty on redistillation. 



The average yield of oil from leaves and terminal 

 branchlets was 1'28 per cent. The crude oil had specific- 

 gravity at 15 C. = 0*9096; rotation a D = + 10'4; 

 ^efractive index at 24 C. = 1/4629, and was soluble in 4 



