president’s ADDRESS — SECTION B. 
43 
gums. The gum of FcJiinocarpus australis , Benth., # has a good deal 
in common with the Sterculia gums and that of three species of 
Elaocarpus ( grandis , cy aliens , obomins ), imperfectly examined by me, 
appear to strongly resemble the group. I notice that Seemann ( Flora 
vitiense ) quotes Mr. S torch as having found a gum-res in on E. StorcJcii , 
Seem., from Fiji. This exudation should be further examined. 
As recent work in the gums, &c., of the dry interior, I may refer 
here to my examination of the exudations collected by the Elder 
Expedition.f Professor Tate has also just placed in mv hands the 
exudations collected by the Horn Expedition, which, though few, 
appear to be very interesting. 
The aromatic Natural Order Eutacere is hardly one in which to 
expect true gums. In India and other places gums have been found 
in Citrus, Feronia , &c. I have gums from Pentaceras australis , Hook, f., 
and Xanthoxylon b racliyacan th um , E. v. M., but have not been able 
to examine them yet. Turning to the Sapindaceae, I have gums from 
two species of Oupania and one of Xep helium. That from Nuytsia 
jloribunda , E. Br., a Loranth from Western Australia, is stated to be 
“a tragaeanth-like gum which swells in water, but does not dissolve. ”J 
It requires examination. 
The gums of Panax§ closely resemble those of Acacia; it would 
be interesting to examine others of the Araliacese. The Terminalia 
gum, used for food both by Leichhardt and Stuart in North-western 
Queensland and the Northern Territory, is described as being very 
similar in appearance to gum tragacanth, but wo know nothing more 
about it, and authentic specimens should be gathered and analysed. 
This brief sketch of our gums shows how little has been done in the 
subject, and how much there remains to be done. 
RESINS. 
Our resins comprise some most interesting substances. In my 
opinion they are the most interesting of the exudations, and I some- 
times wonder why they have not more frequently engaged the atten- 
tion of investigators. The difficulty of obtaining authentic material 
is not present in all cases. For instance, an up-to-date examination of 
the resins so well known as Grass-tree Gum is badly wanted, particu- 
larly as the substance promises to again have some commercial 
importance; I have recently given an account of these “gums”|| 
which may save the chemist some trouble. 
Some of our Coniferous resins are of more than ordinary interest, 
and those of Frenela ( Callitris ) are destined to be of commercial 
importance. They are in every respect identical with the sandarach 
of commerce (the product of Callitris quadrivalvis, Vent.). 
Our Araucarias yield very interesting exudations which are true 
gum-resins — an unexpected occurrence in the Coniferse. MM. 
Heckel and Schl agdenhauffen^f made the first announcement of the 
occurrence of a gum in an Araucaria exudation. Unaware of this 
research, I announced a similar discovery to the Koyal Society of 
* Proc. Linn. Soc. N.S.W. [2], vi., 140. f Proc. R.S. S.A., xvi., 1. 
+ Col. and Ind. Exh. Reports, 1886. § Proc. Linn. Soc. N.S.W, [2], vii., 35. 
II Agric. Gaz. N.S.W., v., 748. 
1 T Comptes rendus, cv., 359 (16th August, 1887). 
