204 
Leaves (Oil). —Messrs. Baker and Smith (Research on the Mucalypts) give 
the following particulars in regard to the oil of this species, and of the so-called 
variety didyma :— 
Species. 
Specific 
gravity at 
15° C. 
Specific rotation, 
Saponification 
number. 
Solubility in 
Alcohol. 
Constituents found. 
E. punctata 
0-9129 to 
- 2-52° to + 4-44° 
18-78 
H vols. 70 % 
Eucalyptol, pinene, 
0-9220 
aromadendral. 
E. punctata var. 
0-9033 to 
- 4-63° to - 6-53° 
10-9 to 11 6 
7 vols. 70 °/ o . to 
Eucalyptol, pinene, 
didyma. 
0-907. 
vols. 80 %. 
aromadendral. 
Flowers. —Large handsome flowers, with a sour offensive smell like sour 
gum arahic. 
Fruit. —Attention is directed to the fact that this is one of the species 
displaying considerable variation in the size and shape of the fruit. 
Bark .—It belongs to the smooth-harked group of gum-trees, and yet as 
compared with the silky smoothness of the White Gum (hcemastoma), or of the 
Blue Gum ( saligna ), its hark is raspy to the touch. As a whole, its trunk may he 
said to have a dirty appearance, often inclining to a yellowish or brownish cast. 
Large pieces of thin, dark-coloured outer hark give it a blotched appearance. I 
have already alluded to this in speaking of “Vernacular names.” 
Timber. —It is so much like Ironbark in appearance that it is difficult to 
discriminate between the two timbers. That will be the best guide to its appearance. 
An expert would usually detect the substitution for Ironbark (if he suspected any 
substitution), by noting that a chip of Grey Gum is more brittle than that of 
Ironbark ; it also cuts less horny. Nevertheless, the two timbers are wonderfully 
alike, and for many purposes Grey Gum is an efficient substitute for Ironbark, for 
it is remarkably durable. Its inferior strength, as compared with Ironbark, 
precludes its use as girders of any length, and when substituted for Ironbark in 
sleepers the holts and spikes work loose in them. I would encourage its use in 
every possible way for wood-blocks, 'flic chief objectors to its use at the present 
time are the saw-millers themselves, as the logs often contain gum-scabs or gum- 
veins. At present, where unblemished timber is insisted upon for wood-blocks, a 
saw-miller cannot afford to cut up Grey Gum (although it frequently turns out 
unblemished), because of the risk of having it condemned. I will speak on this 
subject in connection with Bloodwood, and would emphasise the opinion that wood¬ 
blocks should not be condemned because they contain a few gum-scabs or veins. 
Such excess of care practically leads to great waste of really valuable timber. It is 
recommended for paving-blocks, as already stated. It is in high repute for posts, 
having excellent records when employed in this very trying situation. I have seen 
it used for felloes and for shingles. It is very largely used as an Ironbark 
substitute for railway sleepers, Ac., which fact is in itself testimony to its excellence. 
