ON THE PINES OF AUSTRALIA. 155 
material of C. glauca; but with both C. robusta from West 
Australia, and C. verrucosa from New South Wales—closely 
allied species—separate determinations were undertaken. 
It will be noticed that in the results, obtained with the 
material of C. glauca from Narrandera, 25/4/07, the oil 
from one large tree (kept separate) varied by 6°7° from 
that obtained from trees growing alongside, and that 
the ester content was less also. The branchlets from 
the single tree had numerous fruits, and considerably more 
than were present on the general material. These differ- 
ences, however, are so well under control, that it is prac- 
tically possible to decide the species of Callitris, when 
judged from an investigation of the oil constituents, pro- 
viding no mixture of material from various species has 
taken place. The advantages of this will eventually be 
self-evident when the complete results are published. The 
distillations were continued for six hours in all cases, 
except with No. 7, as it was found that a fair quantity of 
oil came over during the fifth hour. 
The main constituents of the oils of all the samples of 
C. glauca were the same, and the higher boiling fractions 
in all cases were highly dextrorotatory, due to the presence 
of dextrorotatory bornylacetate and dextrorotatory borneol. 
The comparative uniformity of results with the several 
fractions, obtained with the five samples redistilled, can 
be seen from the tabulated results, Table II. The crude 
samples of oil were mostly slightly yellowish in tint, and 
only one or two were reddish in colour. The material was 
distilled in iron vessels. When cleared by dilute aqueous 
solution of soda, the oil was almost colourless, being slightly 
yellowish in tint. When rectified by steam, or by direct 
distillation, it was quite colourless. In both odour and 
appearance the leaf oil of this species of Callitris compares 
favourably with the better Pine-needle oils of commerce, 
