166 H. G. SMITH. 



this class. It seems quite unnecessary, therefore, to go to 

 the expense of redistilling the crude oil of Eucalyptus 

 Smithii, as it can so readily be prepared in a marketable 

 condition by simpler methods. 



The material which has furnished the oils for the present 

 investigation was all collected from trees growing at Hill 

 Top, in this State, with the exception of that from the 

 cultivated tree at Marrickville. The leaves and terminal 

 branchlets were, in all cases, cut as for commercial oil 

 distillation and were distilled at the Technological Museum, 

 with the exceptions of (f) and (g) below, which were dis- 

 tilled by Mr. Ohalker. 



The material worked upon is represented by the following 

 stages of growth: — 



(a) Leaves from lopped trees, seven months' growth ; col- 



lected May 1913. 



(b) Leaves from lopped trees, fifteen months' growth; col- 



lected May 1913. 



(c) Leaves from seedlings, twelve months' growth; col- 



lected June 1914. 



(d) Leaves from seedlings two and a half years old; col- 



lected July 1914. 



(e) Leaves from cultivated tree at Marrickville; collected 



June 1915. 



(f) Leaves from general material, partly young; collected 



January 1915. 



(g) Leaves from general material collected three weeks 



later than (f). 

 (h) Leaves from old trees; collected March 1913. 



The constants etc. given by the crude oils from the above 

 material were as follow: — 



