1-7 



The Variation in the Character of Eucalyptus Oils 



Distilled from Trees of Differing Ages 



and Forms of Growth. 



I in d I [iven in the previous article dealing with the comparative consl 

 oi the oil products, only treat with those distilled from general material, and 

 no1 from individual trees or selected growths. In order, therefore, to determine 

 the variation in amount of constituents in oils from such material thai mighl 

 be expected, the following work was undertaken. 



With the exception oi two samples oi E. Smithii f and g), which were 

 distilled by Mr. I>. E. Chalker, of Hill Top, New South Wales, from general 

 material, all were prepared at the Technological Museum, the leaves having been 

 specially collected foi the investigation, and with the exception oi e all were 

 from naturally growing trees. 



The results dealing with the oils oi E. Smithii were published in the Proc. 

 Roy. Soc, N.S.W., August, mi> 



I ho material worked on is represented by the following stages oi growth : 



a Leaves from lopped trees, seven months' growth ; collected May, E913. 



(6) Leayes from lop] ed trees, fifteen months' growth ; collected May, 1913 



c Leaves Erom seedlings, twelve months' growth ; collected June, 193 |. 



d Leaves from seedlings two and a hall years old ; collected July, 1914. 



(e) Leaves from tree cultivated al Marrickville, near Sydney; collected 



Juno, 11)15. : Tree, .;'. years old . 

 (/) Leaver from general material, partly young ; collected January, r.915. 

 g I eaves from general material collected three weeks later than (/). 

 /; Leaves from old trees ; collected March, 1913. 

 The constants, &c, given by the crude oils from the above material were as 

 follows : — 



The cineol was in all cases determined by the resorcinol method, in the 

 tilled portion oi the freshly obtained oils boiling below n,o ('. and 

 1 all ulated lor tin- original oil. 



h will he noticed from the above table th.it the oil from the younger 

 seedlings contained more dextro-rotatory pinene and less cineol than did thai 

 from the saplings two to three yeais old, and thai the maximum cineol content 

 was velud in the ml from leaves collected from older trees. This is true also 



