3i7 



the statemenl has been made thai al certain times ol the year, the yield is 

 greater than thai obtainable from the leaves al the same period. 



The results of the investigation on the oil from the bark show it to be identical 

 in composition with thai obtainabL from the leaves, so thai no separation need 

 be made for commercial purposes. With trees ol fail size, il should 1"' profitable 

 to steam distil the bark for its oil, thai is, il h be considered u to i nl down 



the trees in the process ol manufacture. The growth oi "suckers" from the 

 stumps "t the felled trees is, however, somewhal rapid, so thai new material 

 would soon be available, and, as shown above, an excellenl "il is obtainable from 

 this young foliaceous grow th. 



The bark was chopped into small pieces, coarsely ground in a mill, and 

 steam-distilled. The yield of oil was equal to 0-12 per cent. 



The crude oil was ol a light amber colour, and had a distinct odour of 

 geranyl-acetate. It gave the following results: — 



Specific gravity at 15° C. ... ... ... ... = 0-9214. 



Optical rotation a D ... ... ... ... ... + 1-2°. 



Refractive index at 20 C. ... ... ... = 1-4718. 



Soluble iu t-2 volumes 70 per cent, alcohol. 



The optii al activity of the oil was due to the presence of a small quantity 

 of dextro-rotatory pinene. The stearoptene eudesmol, which is a constant 

 constituent in the leaf oil, does not appear to be present in the bark oil. 



The saponification number for the esters in the cold with two hours' contact 

 was 169-5, equal to 59-3 per cent, geranyl-acetate. 



A portion of the oil was then acetylated in the usual way. Hie saponi- 

 fication number with this acetylated oil in the cold was 198-8, equal to 69-6 per 

 cent, of ester. The saponification number had thus increased by 29-3, so that 

 the free geraniol in the oil was 8 pei cent. 



A sample of crude oil from the bark of this species distilled in October, at 

 Wingello, by Mr. W. J. Quigg, was also investigated at the Technological Museum. 

 It contained a larger amount of ester than did the oil distilled by us, and had the 

 following characters : 



Specific gravity at 15° C... ... ... ... = 0-9099. 



Optical rotation a D ... ... ... + 1-4°. 



Refractive index at 20 ... ... ... ... = 1-4648. 



Soluble in 1-2 volumes 70 per cent, alcohol. 

 The saponification number for the ester in the cold with two hours' contact 

 was 195, equal to 68-2 per cent, geranyl-acetate. 



The saponification number for the acetvlated oil, also in the cold, was 22^. 

 equal to 78-4 per cent, oi ester, an increase in the saponification number of 29, 

 representing about 8 per cent, of free geraniol in the crude oil. 



A coramen ial sample of the bark oil of this species, presented to the Museum 

 by De Meric Ltd., George-street, Sydney, had the following characters :— 

 Specific gravity at i5°C. ... ... ... = 0-9218. 



Optica] rotation a D ... ... ... ... + 1-2°. 



Refractive index at 20 ... ... ... ... = 1-4711. 



Soluble in 1-2 volumes 70 per cent, alcohol. 

 The saponification number in the cold with two hours' contact was i<>(), 

 equal to ^r- per cent, geranyl-acetate. 



This Eucalyptus is one of the very lew species ol the genus from which an 

 ■ 1 ntial oil 1 an be distilled from the bark, and, SO fai as at present known, it is 



the onh Eucalyptus bark 0! commercial value !"■ oil production. 



