178 R. W. CHALLINOR, E. CHEEL, AND A. R. PENFOLD. 
in nearly equal proportion, and in this respect appears to 
occupy a position intermediate between the oils from 
Eucalyptus citriodora and Backhousia citriodora, both of 
which give the highest recorded yields of the respective 
aldehydes citronellal and citral. 
The relative proportions of these two aldehydes are also 
apparent from the specific gravity and refractive index of 
the oil, these constants being approximately what might 
be obtained when citronellal and citral are mixed in equal 
proportions. 
Hxperimental.—Three lots of material were collected at 
Copmanhurst, New South Wales, in September 1916, by 
Dr. T. Guthrie, Messrs. H. Cheel, and A. D. Ollé; in 
January 1917 by Mr. R. W. Challinor; and in November 
1917 by Mr. EK. Cheel. Altogether 686 ibs. of leaves and 
terminal branchlets were distilled, the yield of oil averag- 
ing from 1°73 to 1°85%. The crude oil was of a pale amber 
colour, of specific gravity 72° C. 0°8841; optical rotation 
ay +3°6 at 18° C.; refractive index 1) 20° O. 1°4730; con- 
tained 90% aldehydes and was soluble in 2 volumes of 70% 
alcohol (by weight). 
The Aldehydes.—The aldehyde content of the oil was 
determined quantitatively by the sodium bisulphite method. 
5 c.c. of oil leaving 0°55 c.c. unabsorbed oil, another 5 c.c. 
left a residue of 0°5 c.c., which indicates 897% and 90/ 
respectively of constituents absorbed by sodium bisulphite. 
A larger quantity of the oil was then treated, 50 c.c. at 
a time, and the non-aldehydic portion separated, the 
aqueous solution was extracted several times with ether to 
remove undissolved oily matter, the ether was distilled off, 
and the aldehydes regenerated by means of alkali, dried 
over anhydrous Na.Suc. and separated into two fractions, 
fraction 1, boiling at 938-94° C. (12 m.m.) and consisting 
approximately of 48% of the original oil, and Fraction 2, 
