S82 
[FliBRUARY I, li?92. 
THE CHEMISTRY AND COMMERCIAL 
POSSIBILITIES OF WATTLE GUM. 
BY J. H. MAIDEN, F.L.S., F.C.S., 
Curator of tin' I'echnolof/ical Mtixenm, of Xen- Sonlh 
Wah'.o. 
The subject acquires additional interest on ac- 
count of the short suijply of good gnni arable, and 
the categorical statement whicli lias been more 
than once made that Australia )iiight meet the de- 
mand. Although a connnon product, seen and known 
by everyone in the Colonies, it is singular that wattle 
gum has not hitherto formed the subject of syste- 
matic reseach. In the following pages I have 
treated the subject both from a botanical and 
chemical point of view, and have, I believe, included 
all published references to the subject. My researches 
and observations, conducted with exceptional facili- 
ties for thoroughly sifting the subject, have caused 
me to arrive at "the conclusion that Europe and 
America must not look to Australia for any quantity 
of high class gum. 
"Wattle gum is the produce of various Australian 
.species of Acacia, a genus which is very largely 
developed in that continent, comprising about 820 
species, besides a large number of well marked va- 
rieties. 
Gum has, however, only been recorded from com- 
paratively few species, as by far the great majority 
have no local names, and where it has been collected 
at all it has usually been styled "wattle gum." The 
present paper includes all species known to the 
author as having yielded gum in Australia ; several 
of the gums are now recorded or described for the 
first time. The specimens described are in the Tech_ 
nological Museum. 
Speaking of Wattle gums in general, Bentley and 
Trimen, ' Medicinal Plants,' say, " It is found com- 
monly in large tears or masses of a dark yellow or 
reddish-brown colour. This gum, which has a trans- 
parent appearance, being nearly free fr ^m cracks or 
fissures, is said to be readily soluble* in water, and 
to form a very adhesive mucilage. It is frequently 
contaminated with pieces of the astringent barks of 
the trees from which it is obtained, hence its solu- 
tion, unless carefully prepared, will frequently contain 
some tannic acid." This is an objectionable con- 
stituent, as it affects the mordants in calico printing. 
" Best selected Turky gum " is the ideal gum of 
the group to which Wattle gum belongs, and if 
judging were to be by points, it would take the 
highest place as regards absence of colour, freedom 
from accidental impurities, ready solubility, and ad- 
hesiveness of its mucilage. Tlie Australian gums 
seen by the author for the most part full far behind 
this high standard, although specimens of those from 
honiaJojilii/lla, ^1. jiriiiliihi, A. sciifin, and Fhii- 
(Irrxia marulosa compare with it very favourably. 
As far as his experiments go, those samples ob- 
tained from the interior (comparable in its aridity 
to the Soudan and other noted gum-producing 
countries), are completely soluble in water, and make 
good mucilages, while those obtained east of the 
Dividing Range, i.r., in well watered districts, in 
whic vegetation is comparatively luxuriant, are 
more r less insoluble, portions, at least, merely 
Hwellin g up in water, like cherry gum. In other 
word (D (speaking of the Eastern colonics, in the ah- 
scnceoof detailed knowledge of the western one), 
the c^aKt Wattle gums contain metaraljin, while the 
interi r ones do not, And when it is borne in, mind 
^ha.t the yield of gum in the interior is insignificant 
• Perhaps this Btatement has arisen from the fol- 
lowing : — " Ooncrally speaking, the Victorian acacia 
giiiMK arc Homcwliat less sohiblo tlian tlic gum araliic 
of com mcrcc, Imt, on Mie otlier liand, tlioy appear 
to yield a inoie adliesivo mucilage, wliicli is less 
IJuble to Hplintcr and ci'ack when diy " fltr/iort on 
/iirHfi. J'li/ii. Siilixl., Victorian lOxiiiliition, 1S(11.) 
'J'his HtM Jiiient given an ex^iggcr.U.cd idea, of tbe 
value of Victorian gu iiH, and of Australian ones 
gencralljj 
as compared with that of the coast country, it be- 
comes apparent how hazardous is any generalization 
til at Australian gums are readily soluble in water. 
I do not think there is much commercial future 
I before Australian gum, on account of the high price 
of labour, except in the few localities where gum is 
very abundant and of high quality, and because the 
natural gum-yielding trees have been largely destroyed 
for their tan-bark and for firewood. 
Wattle gum exudes chiefly during the summer 
season from fissures and accidental injuries to the 
bark. After careful observation, I have formed the 
opinion that, as a very general rule, it is a patho- 
logical product. I came to this conclusion long 
before I was aware of Trecul's observations, that 
Acacias and the Rosaceas yield their gums most 
abundantly when sickly, and in an abnormal state 
caused by a fulness of sap in the young tissues. 
Wattle gum of various species is largely eaten by 
the blacks, and, by those of the interior at least, 
especially with fish. This fact is well-known in the 
Colonies, and I give a few quotations from explorers 
on the subject. Following is Captain Sturt's account 
of the occurrence and use of Wattle gum by some 
natives of Central Australia : — " Among other things 
we found a nuiiiVjer of Ijsjk troughs tilled with the 
gum of the mimosa, and vast quantities of gunt 
made into cakes upon tbe ground. From this it 
would appear that these unfortunate creatures were 
reduced to the last extremity, and being unaljle to 
procure any other nourishment, had been obliged 
to collect this mucilaginous food" ('Two Expedi- 
tions into the Interior of South Australia, ' etc., 
1828-;!1, i., lis). Captain Sturt was not then aware 
that the natives by no means look upon Wattle gum 
as starvation food. 
Captain J. Lort Stokes (' Discoveries in Australia ') 
gives " Minnung " as the name of a Western Aus- 
tralian Acacia whose gum is "very abundant," and 
eaten by the nati\es. 
Captain (now Sir George) Grey gives the following 
account of the use of Wattle gum {? A. microhotri/a) 
by the natives of Western Australia: — 
" The gum of the mimosa is a favourite article of 
food amongst the natives .... Kn-an-tiat is the kind 
of gum which most abounds, and is considered the 
nicest article of food. It is a species of gum 
tragacanth (sii:). In the summer months the Acacias, 
growing in swampy plains, are literally loaded with 
this gum, and the natives assemble in numbers to 
partake of this favourite esculent. As but few places 
afford a sufficient supply of food to support a large 
ajssemblage of persons, these Kwonnat grounds are 
generally the spots at which their annual barter- 
meetings are held, and during these fun, frolic and 
quarrelling of every description prevail." ('Journal 
of Two Expeditions,' etc., ii., '260, 204). Captain 
Grey also makes the intere- ting statement (p. 298 ) 
that some of these Kwonnat grounds appear to be 
visited by numerous families by acknowledged right 
at the period when the gum is in season, although 
not allowed there at any other time. This heredi- 
tary ownership is very rare amongst the aboriginals, 
although it is exercised in the well-known instance 
of the .Iraiwaria BidiriUi, of Queensland. 
Small boys eat the more insoluble gums, parti- 
cularly when made into a jelly and sweetened (see 
^1. di'i: unriix). 
Wattle gum is considered useful in diarrhoea (in 
such oases a little astringency would of course be 
n,n advantage rather than a drawback) and piles. It 
is also said to be employed in veterinary practice 
in the country for woppds and raw shoulders in 
liovses. 
I have been shown a statement by " a good 
practical man " that Wattle gum dissolved in beiir 
/.olc " makes an excellent carriage vanish." Perhaps 
licre will be a convenient opportunity to point out 
tluit Wattle gum is quite insoluble in that liquid, 
I to say nothing of the lidiculous suggestion to use a 
li ne gum for a varnish, and to protest against the 
reckless statements which are made in regard to out 
little known raw products. 
XI would appear that some species, which in their 
