42 
president’s ADDRESS SECTION R. 
I have published analyses of a large number of Acacia gums ; but 
there are a large number of others yet to be identified and examined, 
as gums of this kind are usually mixed together by collectors. While 
speaking of this genus, we know nothing of the composition of the 
clammy substance (probably resinous) found on the leaves of 
A. vernicijiua , A. Cunn. (syn. A. exudans , Lindl.), and first remarked 
upon by Sir Thomas Mitchell. 
I will refer to a few other leguminous gums in alphabetical order 
of genera. Adenantliera pavonina , Linn., is found in India, Ceylon, and 
North Queensland. In Ceylon it yields a gum called Madatia, but 
we know nothing of its properties or composition. Albizzia porcera, 
Benth., yields a partially soluble gum; and other Albizzias and. Fithe- 
colobiums will probably be found to yield similar gums. 
A small quantity of the gum of Gastan ospermum australe. A. Cunn., 
in my possession seems to resemble the StercuUa gums, but I have not 
yet examined it. I have also a small quantity of the gum of Derris 
scandens , Benth. I have not yet seen the gums of our Erythrinas ; 
an Indian-grown specimen of E. indica , Lam., is stated to be a “ brown 
gum of no value.” A very large plant (stem about an inch in 
diameter) of Kennedga rubicimda , Vent., has yielded a little gum. I 
have described a kino from Milletia (Wistaria) megasperma , F, v. M., 
and a gum from Mezoncuron Scortechinii, F. v. M., # and have since 
acquired a little gum from M. brachgcarpum . Bed Cedar gum ( Gedrela 
australis , F. v, M.) and gum of Flinders ia maculosa , F. v. M.,f have 
been analysed and possess interest, if only because they are the only 
gums of our Australian Meliacefe yet examined. I have received a 
true gum from F. australis , B. Br., and a small quantity of a gum 
from Bog Onion ( Owenia cepiodora,F. v. M.), but have not examined 
them, and would point out to chemists that we know nothing of a 
true gum from any other Australian genus of Meliacere. 
The Macrozamia ( Enceplialartos ) gums appear to be practically 
the same, no matter the species. I have examined J\£. perowskiana , 
Miq., and M. spiralis, J Miq. They mainly consist of metarabin. 
Since 1 found pararabin in StercuUa gum,§ I have examined 
other Sterculiaceous gums ( Harriet ia , &c.) with similar results. There 
appears to be a good deal of uniformity in gums of this Natural 
Order. 
Coming to the Malvaceae, the “nutritious white gum,” spoken of 
by Grey|| as having been found on the bark of the Grouty Stem-tree 
( Adansonia Gregorii , F. v. M.), would appear to be closely allied to 
the above. It does not appear to have been examined, neither has the 
“dark-red gum” spoken of by Bentham (FI. Aust.) as exuding from 
the fruit. No one has yet examined the “rich yellow gum on the 
seed-vessels, like gamboge,” described by Bev. J. E. Tenison- Woods 
as occurring on Thespcsia populnea, Corn, in Northern Queensland. 
The Tiliaceao are closely allied to these two Natural Orders, and 
it is not surprising to find that the family likeness extends to their 
* Proe, Linn. Soc. N.S.W. [2], vi., 679. 
f Proe Linn. Soc. N.S.W. [2], iv., 1047 ; Proc. A.A.A.S., ii„ 379. 
X Chem. and Drugg. of Australasia, Jan. — Feb., 1890. 
§ Pharm. Journ., [3], xx., 381. 
|| Journal of Two Expeditions, &c., p. 112. 
