Brown), renders most important service in subduing loose coast-sand
the lower branches striking root into the so il; it should therefore be
disseminated on extensively bare sand-shores in regions, where no
severe frosts occur. The hark of A. longifolia is only half as good as
th a t 01 A. mollissima for tan, and used chiefly for sheep-skins The
tree is of quick growth.
A c a c ia m a c r a n th a , Bentham.
From Mexico to Argentina, also in the Galapagos-Group. This
tree, usually small, provides the “ Cuii-pods ” for tanning- fSim-
monds]. ®
A c a c ia M e la n o x y lo n , R. Brown.*
South-Eastern Australia. Ascends to sub-alpine country. Generally
known as Blaekwood-tree, passing also under the inappropriate
name of Lightwood-tree. In irrigated glens of deep soil the
tree will attain a height of 80 feet, with a stem several feet in
diameter. The wood_ is most valuable for furniture, railroad-cars
and carriages, boat-building (stem and stern-post, ribs, rudder), for
tool-handles, crutches, stethoscopes, some portions of the work of
orgau-builders, billiard-tables, pianofortes (for sound-hoards and
actions) and numerous other purposes; it has also come into use for
casks, which need however previous long soaking. Planks 12 feet
by 4_ feet are occasionally obtainable for select purposes. Specific
gravity of the dry wood 0-664-0-777. The Victorian Eailway-
Lominissioners report it for railway-carriages better adapted than
almost any other timber, being handsome and durable, and not particularly
expensive; wood from hilly country is also in this instance
superior to th a t from low and particularly wet localities. The
fine-grained wood is cut into veneers; it takes a fine polish, and is
considered almost equal to walnut. The best wood in Victoria for
bending under steam; it does not warp and twist. Local experiments
p v e the strength in transverse strain of Blackwood equal to Euca-
^ptiis-wood of middling strength, approaching th a t of the American
W h p Oak, and surpassing th a t of the Kauri. The bark contains
up to 20 p e rc en t, mimosa-tannin. The tree has proved, with A.
mollissima and A. dealbata, hardy in the Isle of Arran IRev. D.
L a n d sb o rp g h ]. Mr. T. R. Sim states th a t it thrives well in Cape
Colony wherever it finds plenty of root-moisture, but without th a t
it dies out early.
A c a c ia m ic ro b o try a , .Bentham.
South-Western Australia. The “ Badjong.” A comparatively
tall species, the stem attaining a diameter of 1 to U feet. I t prefers
naturally. According to Mr. Geo.
Whitfield, a single tree may yield 50 lbs. of gum in a season. The
aborigines store the gum in hollow trees for winter-use; it is of a
. pleasant, sweetish taste.
A c a c ia m o llis s im a , Willdenow.*
The Black Wattle of South-Eastern Australia and Tasmania. I t
seems best to re-adopt the systematic names, by which our three
principal feather-leaved wattles were distinguished during the first
half of the century. The systematic aflfinity of A. mollissima is
nearer to A. dealbata than to A. decurrens, the differences having
already been set forth under those' two species. I t is generally a
middle-sized tree, its wood being used for staves, occasionally also for
piok-handles and similar purposes, but principally serving as an
excellent fuel. A chief use of the tree would also be to afford the
first shelter in treeless localities for raising forests in regions where
no severe frosts occur. I t also exudes a useful gum. By far its
greatest importance however rests upon its bark, so highly valuable
for tan n in g ; indeed it seems destined to stand ahead of all the other
tan-trees of the world through the facility of its culture in suitable
localities and the strength of its product. Mr. James Dickinson states
th a t he has seen 10 cwt. of fresh bark obtained from a single tree of
gigantic dimensions at Southport. A quarter of a ton of bark was
got from one tree a t Tambo, without stripping all the branches. The
height of this tree was 60 feet, and the stem 2 feet in diameter.
The English price of the bark ranges generally from £7 to £12. In
Melbourne it averages about £ 5 to £10 per ton. I t varies, so far
as experiments made in my laboratory have shown, in its contents
of tannic principle from 30 to 40 per cent, in bark completely dried,
but this is not all pure tannic acid. In the mercantile bark the
percentage is somewhat less, according to the state of its dryness,
it retaining abont 10 per cent, moisture. 1-^ lbs. of Black Wattle-
bark give 1 lb. of leather, whereas 5 lbs. of English Oak-hark are
requisite for the same results ; but the tannic principle of both is
not absolutely identical. Melbourne tanners consider a ton of
Black Wattle-bark sufficient to tan 25 to 30 hides ; it is best
adapted for sole-leather and other so-called heavy goods. The
leather is fully as durable as th a t tanned with oak-bark, and nearly
as good in colour. Bark, carefully stored for a season, improves in
tanning power considerably. From experiments made under the
author’s direction it appears, th a t no appreciable difference exists
in the percentage of tannin in Wattle-bark, whether obtained in
the dry or in the w-et season. The tannin of this Acacia yields a
grey precipitate with ferric and a violet colour with ferrous salts ;
it is completely precipitated from' a strong aqueous solution by
means of concentrated sulphuric acid. The bark improves by age
and desiccation, and yields about 40 per cent, of catechu, rather
more than h a lf of which is tannic acid. Bichromate of potash
added in a minute quantity to the boiling solution of mimosa-
tannin, produces a ruby-red liquid, fit for dye-purposes ; and this
solution gives with the salt of sub-oxide of iron black pigments,
and with the salts of the full oxide of iron red-brown dyes [F . v. M.
and Rummel]. As far back as 1823 a fluid extract of Wattle-bark
was shipped to London, fetching then an extraordinary price.