170 A. R. PENFOLD. 



THE ESSENTIAL OIL OF LEPTOSPERMUM 

 FLAVESCENS (SMITH). 



By A. R. Penfold, f.c.s. 



[Read before the Royal Society of N. S. Wales, October 5, 1921.'] 



The essential oils described in this paper are those obtained 

 by distilling the leaves and terminal branchlets of the tea 

 tree described by Smith in Transactions of the Linnean 

 Society, Vol. Ill, (1797), page 262. It is a tall, graceful 

 shrub, varying from about four to twelve feet in height, 

 found growing extensively in the coastal and mountain 

 districts within about 100 miles of Sydney. It is one of 

 the commonest of our tea trees, and it is somewhat sur- 

 prising that its essential oil has not previously been inves- 

 tigated. At various periods of the year, and from shrubs 

 growing in different localities, a pleasant faint lemon-like 

 odour is detected upon crushing the leaves. This is shown 

 in this paper to be due to small amounts of the aldehyde,, 

 citral, varying from 0'25% to 0*75%. Leaves and terminal 

 branchlets were obtained from a number of distinct 

 localities, such as Longueville (Lane Cove River, Sydney)* 

 Kuring-gai on the Northern Line, 25 miles from Sydney, 

 Hill Top, southern district, N.S.W., 80 miles, and Black- 

 heath on the Blue Mountains, 75 miles from Sydney. 



The Essential Oil. 



The oils obtained from the different consignments of 

 leaves of this species were of a deep yellow to greenish- 

 brown colour, somewhat viscous and possessing a pleasant 



