COMMERCIAL TANNING MATERIALS.
=Algarobilla.=--The seed-pods of _Prosopis pallida_ and _P. Algarrobo_
are known as _algarobilla_, the two kinds being distinguished as
_negro_ and _blanco_. The trees are abundant in mountainous parts
of South America, notably Chili and the Argentine Republic. The
pods contain up to 50 per cent. of a bright-yellow tannin, somewhat
resembling that of myrobalans. The friable tannin is readily soluble
in cold water, and is so loosely held in the fibrous network of the
pod, that great loss is sustained by careless handling. The commerce
in algarobilla does not figure in the official trade returns; but J.
Gordon & Co., Liverpool, obligingly state that they imported 50 tons,
at an average value of 18_l._ 10_s._ a ton, in 1880. Widow Duranty &
Son, also of Liverpool, are good enough to add that they received 160
tons in 1881, the first that had reached them for a long time. Havre
imported 50 tons in 1881. The name _algarrobo_ is also applied to
_Balsamocarpon brevifolium_ in Chili, and to _Hymenæa Courbaril_ in
Panama.
=Chestnut-extract.=--The wood of the chestnut (_Castanea vesca_)
contains 14-20 per cent. of a dull-brown tannin. It is quite different
from the bark and bark-extract of the American chestnut-oak (_Quercus
sessiliflora_). Its extract is used largely to modify the colour
produced by hemlock-extract, and for tanning and dyeing. The pulverised
wood is also extensively employed in France. The imports are included
in barks and extracts, p. 39.
=Cork-bark.= See Oak-barks.
=Cutch, Catechu, or Terra Japonica= (Fr., _Cachou_; Ger.,
_Catechu_).--The term _kát_, _kut_, or "cutch," is applied to the
dried extract, containing 45-55 per cent. of dark-coloured mimo-tannic
acid, prepared chiefly from 2 trees:--(1) _Acacia Catechu_ [_Mimosa
Catechu_, _M. sundra_], a tree of 30-40 ft., common in most parts of
India and Burma, growing also in the hotter and drier districts of
Ceylon, and abundant in tropical East Africa--the Soudan, Sennar,
Abyssinia, the Noer country and Mozambique, though the utilisation of
its tannin is restricted to India; (2) _A._ [_M._] _Suma_, a large tree
inhabiting South India (Mysore), Bengal, and Gujerat.
The process for preparing cutch varies slightly in different districts.
The trees are reckoned to be of proper age when their trunks are about
1 ft. diam. They are then cut down, and the whole of the woody part,
with the exception of the smaller branches and the bark, is reduced
to chips: some accounts state that only the darker heart-wood is thus
used. The chips are placed with water in earthen jars, arranged in a
series over a mud fire-place, usually in the open air. Here the water
is made to boil, the liquor as it becomes thick and strong being
decanted into another vessel, in which the evaporation is continued
until the extract is sufficiently inspissated, when it is poured into
moulds made of clay, or of leaves pinned together in the shape of
cups, or in some districts on to a mat covered with the ashes of burnt
cow-dung, the drying in each case being completed by exposure to the
sun and air. The product is a dark-brown extract, which is the usual
form in which cutch is known in Europe.
In Kumaon, North India, a slight modification of the process affords
a drug of very different appearance. Instead of evaporating the
decoction to the condition of an extract, the inspissation is stopped
at a certain point, and the liquor is allowed to cool, coagulate,
and crystallise over twigs and leaves thrown into the pots for the
purpose. By this method is obtained from each pot about 2 lb. of _kath_
or catechu, of an ashy-whitish appearance. In Burma, the manufacture
and export of cutch form one of the most important items of forest
revenue. The quantity of cutch exported from the province in 1869-70
was 10,782 tons, valued at 193,602_l._, of which nearly half was the
produce of manufactories situated in British territory. The article is
imported in mats, bags, and boxes, often enveloped in the large leaf of
_Dipterocarpus tuberculatus_. It is brought down from Berar and Nepal
to Calcutta. That of Pegu has a high reputation.
Our imports of cutch in 1880 were 5155 tons, value 173,040_l._, from
the British East Indies; 539 tons, 15,572_l._, from other countries;
total, 5694 tons, 188,612_l._ Our exports in the same year were:--892
tons, 28,527_l._, to Germany; 676 tons, 24,562_l._, to the United
States; 478 tons, 15,505_l._, to France; 303 tons, 10,537_l._, to
Holland; 177 tons, 5859_l._, to Russia; 141 tons, 4835_l._, to Belgium;
245 tons, 8719_l._, to other countries; total, 2912 tons, 98,544_l._
The approximate London market value of Pegu cutch is 21-42_s._ a cwt.
An astringent extract prepared from the areca nut (_Areca Catechu_) is
said to contribute to commercial cutch; if so, it is a totally distinct
product from those just described.
=Divi-divi, or Libi-dibi.=--These names are applied to the seed-pods of
_Cæsalpinia coriaria_, a tree of 20-30 ft., indigenous to several of
the West Indies, Mexico, Venezuela, and North Brazil, and naturalised
in Madras and Bombay Presidencies, and in the North-West Provinces.
The pod may be known by its drying to the shape of a letter S; it
contains 30-50 per cent. of a peculiar tannin, somewhat similar to that
of valonia. It is cheap, and may be used in admixture with barks; but
it is dangerously liable to undergo fermentation, suddenly staining
the leather a dark-red colour, and is therefore not in extensive
use. The imports of it are mainly from Maracaibo, Paraiba, and St.
Domingo. Maracaibo, in 1880, exported 197,674 lb. of divi-divi, value
3222-1/4 dol. (4_s._ 2_d._), to New York. Our imports of divi-divi into
Liverpool, according to figures kindly furnished by Haw & Co., were
2200 tons in 1877, 1740 in 1878, 2132 in 1879, and 780 in 1880. The
approximate market value is 12-17_l._ a ton.
=Galls.=--The generic term "gall" is applied to those excrescences on
plants which are produced by the punctures of insects, for the purpose
of depositing their eggs. The excrescences are usually considered to be
a diseased condition of vegetable tissue, resulting from the injection
of some secretion of the insects. But this has been combated by A.
S. Wilson, of Aberdeen, who considers that all insect galls are in
reality leaf-buds, or fruit-buds, and not mere amorphous excrescences.
The vascular lines which would form leaves can easily be followed up
in the structure of the oak-leaf galls. And in cases where the egg
has been deposited in the tissue of a young branch, the cap of the
gall is sometimes surmounted by a leaf 2-3 in. long. But in the large
blue Turkish galls, many lacunæ occur where the fleshified leaves have
not filled up the spaces between them. If a dissection be made of one
of the weevil-galls on the bulb of the turnip, the second or third
slice will show the outer foliations, exactly similar to those of the
root-buds. When the centre has been reached, where the maggot will be
found, there will also be a vascular pencil running up from a medullary
ray in the bulb, and bearing on its top a bud of the same description
as that produced by a ray running out from a root. The insertion of the
ovipositor brings a medullary ray into action, producing a tuberculated
bud, and it is only the bud which the larva feeds upon. The growth of a
bud is an intelligible cause of the growth of a gall, but nothing can
be inferred from the injection of a fluid. The analogy to leaves is
further shown by the fact that various microscopic fungi are matured in
the interior of imperforate galls.
The principal commercial kinds of gall are oak-galls and Chinese galls.
_Oak-galls_, _Nut-galls_, _Aleppo_ or _Turkey-galls_ (Fr., _Noix de
Galle_, _Galle d'Alep_; Ger., _Levantische_ or _Aleppische Gallen_,
_Galläpfel_).--These are formed by the punctures of _Cynips_
[_Diplolepis_] _Gallæ tinctoriæ_ on _Quercus lusitanica_ var.
_infectoria_ [_Q. infectoria_], a shrubby tree of Greece, Cyprus, Asia
Minor, and Syria, and probably other varieties and even species of oak.
The female insect is furnished with a delicate ovipositor, by means of
which she pierces the tender shoots of the tree, and lays her eggs
therein. In the centre of the full-grown gall, the larva is hatched
and undergoes its transformations, finally (in 5-6 months) becoming a
winged insect, and boring for itself a cylindrical exit-hole. The best
commercial galls are those which have been gathered while the insect
is still in the larval state. Such have a dark olive-green colour, and
are comparatively heavy; but after the fly has escaped, they become
yellowish-brown in hue, and lighter. Hence they are distinguished in
the London market as "blue" or "green," and "white." In Smyrna, they
are classified as "white," "green," and "black," the first two sorts
generally fetching nearly the same price, while the black obtain
considerably more, the approximate quotations being: white and green,
per Turkish _oke_ (of 2·83 lb.), 8-1/2-9 _piastres_ (of 2_d._);
black, 13-1/2-14 _piastres_. The "nuts" come mostly from Melemen,
Cassaba, and Magnesia, also from the Syrian coasts, being plentiful
on the east of the river Jordan, and are chiefly forwarded to France,
England, and Salonica. The triennial yield is said to be invariably
the best. They begin to reach Smyrna from the interior towards the
end of July. The crop of 1880 was estimated at over 50,000 _okes_.
The province of Aleppo, which used to afford 10,000-12,000 _quintals_
(of 2 cwt.) annually, only exported 3000 in 1871. The galls collected
in the Kurdistan mountains are marketed at Diarbekir, and sent thence
to Trebizonde for shipment. Bussora, Bagdad, and Bushire also export
considerable quantities.
_Knoppern_, a species of gall formed from the immature acorns of
_Quercus pedunculata_ and _Q. sessiliflora_, are largely used for
tanning throughout Austria.
The exports from Aleppo (including yellow berries) in 1880 were:--60
tons, 3600_l._, to Great Britain; 322 tons, 19,320_l._, France; 15
tons, 900_l._, Italy; 44 tons, 2640_l._, Austria; 55 tons, 3300_l._,
Turkey; 30 tons, 1800_l._, Egypt; total, 526 tons, 31,560_l._ In
1878, the figures were 673 tons, 38,400_l._ Alexandretta exported in
1879 (including yellow berries):--41 tons, 2460_l._, to England; 299
tons, 17,940_l._, France; 20 tons, 1200_l._, Italy; 25 tons, 1500_l._,
Austria; 87 tons, 5220_l._, Turkey; 6 tons, 360_l._, Egypt; total
478 tons, 28,680_l._ The shipments from Trebizonde by steamer in 1880
were (from Turkey):--47 sacks (of 2 cwt.), 188_l._, to Turkey; 240
sacks, 960_l._, Great Britain; 264 sacks, 1056_l._, France; 103 sacks,
412_l._, Austria and Germany; 26 sacks, 104_l._, Greece; total, 680
sacks, 2720_l._; (from Persia): 25 sacks, 100_l._, Great Britain; 31
sacks, 124_l._, France; 30 sacks, 120_l._, Austria and Germany; total,
86 sacks, 344_l._ Bushire despatched 5000_r._ worth to India in 1879.
Syra sent 248_l._ worth to Great Britain in 1879. Venice exported 1745
tons of gall and bark, value 34,906_l._, in 1879.
The best oak-galls contain 60-70 per cent. of tannic or gallotannic
acid, and 3 per cent. of gallic acid. "Rove" is a small crushed gall,
containing 24-34 per cent. of gallotannic acid. There are many other
varieties of non-commercial oak-gall.
_Chinese or Japanese Galls._--These are vesicular protuberances
formed on the leaf-stalks and branches of the _Rhus semialata_
[_Bucki-amela_], a tree of 30-40 ft., common in North India, China, and
Japan, ascending the outer Himálaya and the Khasia Hills to 2500-6000
ft., by punctures of the female of _Aphis chinensis_. The galls are
collected when their green colour is changing to yellow, and are then
scalded. They are light and hollow, 1-2-1/2 in. long, and of very
varied and irregular form. The Japanese are the smaller and paler,
and usually more esteemed. The galls contain about 70 per cent. of
tannic or gallotannic acid, and 4 per cent. of another tannin. They are
consumed mainly in Germany, for the manufacture of tannic acid.
Hankow exported 30,949 _piculs_ (of 133-1/3 lb.) in 1872; and 21,611
_piculs_, value 136,214 _taels_ (of about 6_s._), in 1874. In 1877, the
total Chinese export did not exceed 17,515 _piculs_. Hankow exported
24,742-1/2 _piculs_ in 1878, and 28,392 _piculs_, 59,614_l._, in 1879;
Pakhoi, 62_l._ worth in 1879; Canton, 3155-1/3 _piculs_ in 1877, 1939
in 1878, 3163-1/2 in 1879; Ichang, 100-1/2 _piculs_, 132_l._, in 1878,
402-1/2 _piculs_, 586_l._, in 1879; Shanghai, 27,659-1/2 _piculs_ in
1879.
In China trade returns, they are always miscalled "nut-galls" or
"gall-nuts": correctly, they are _wu-pei-tze_. Oak-galls are exported
from China resembling those of Western Asia. Japanese galls, _kifushi_,
are sent in increasing quantities from Hiogo.
Our imports of galls in 1880 were:--24,590 cwt., 68,697_l._, from
China; 17,311 cwt., 60,648_l._, from Turkey; 9182 cwt., 9013_l._,
from other countries: total, 51,083 cwt., 138,358_l._ Our re-exports
in the same year were:--6260 cwt., 18,479_l._, to Holland; 6022
cwt., 18,147_l._, to Germany; 3214 cwt., 11,002_l._, to France; 3045
cwt., 8598_l._, to Belgium; 2651 cwt., 11,004_l._, to the United
States; 1625 cwt., 5205_l._, to other countries; total, 22,817 cwt.,
72,435_l._ The approximate London market values of galls are:--Bussora,
blue, 82-102_s._ a cwt.; do., white and in sorts, 50-90_s._; China,
50-70_s._; Japan, 55-56_s._
=Gambier, Pale Catechu, or Terra Japonica= (Fr., _Gambir_, _Cachou
jaune_; Ger., _Gambir_).--These names are conferred upon an extract
from the leaves of _Uncaria Gambier_ [_Nauclea Gambir_] and _U. acida_,
containing 36-40 per cent. of a brown tannin, which rapidly penetrates
leather, and tends to swell it, but alone gives a soft porous tannage;
it is largely used in conjunction with other materials for tanning
both dressing- and sole-leather. The plants are stout climbing shrubs,
the first-named being a native of the countries bordering the Straits
of Malacca, and especially the islands at the eastern end, though
apparently not indigenous to any of the islands of the volcanic band,
growing also in Ceylon, where no use is made of it; while the second,
probably a mere variety, flourishes in the Malay islands.
The shrubs are cultivated in plantations, often formed in jungle
clearings; the soil is very rapidly exhausted, and further injured
by excessive growth of the ineradicable _lalang_-grass (_Andropogon
caricosus_). It is found advantageous to combine pepper-culture with
that of gambier, the boiled leaves of the latter forming excellent
manure for the former. The gambier-plants are allowed to grow 8-10
ft. high, and as their foliage is always in season, each plant is
stripped 3 or 4 times in the year. The tools and apparatus for the
manufacture of the extract are of the most primitive description. A
shallow cast-iron pan about 3 ft. across is built into an earthen
fire-place. Water is poured into the pan, a fire is kindled, and the
leaves and young shoots, freshly plucked, are scattered in, and boiled
for about an hour. At the end of this time, they are thrown on to a
capacious sloping trough, the lower end of which projects into the pan,
and are squeezed with the hand so that the absorbed liquor may run back
into the boiler. The decoction is then evaporated to the consistence
of a thin syrup, and baled out into buckets. When sufficiently cool,
it is subjected to curious treatment: instead of simply stirring it
round, the workman pushes a stick of soft wood in a sloping direction
into each bucket; and, placing two such buckets before him, he works a
stick up and down in each. The liquid thickens round the stick, and,
the thickened portion being constantly rubbed off, while at the same
time the whole is in motion, it gradually sets into a mass, a result
which, it is said, would never be produced by simple stirring: it is
reasonable to suppose that this manner of treating the liquor favours
the crystallisation of the catechin in a more concrete form than it
might otherwise assume. The thickened mass, resembling soft yellowish
clay, is now placed in shallow square boxes; when somewhat hardened,
it is cut into cubes, and dried in the shade. The leaves are boiled a
second time, and finally washed in water, which is saved for another
operation.
A second plan is as follows:--The leaves are boiled, and bruised in a
wooden mortar (_lesong_), from which they are put into a kind of basket
of rattan open-work, which is pressed by a long piece of wood acting
as a lever; the liquid is received into a trough, and there allowed to
settle. When the sediment has acquired sufficient substance, it is put
into a _kulit-kayo_, formed like a tub without a bottom, which lets
the superfluous water drain off; when that is done, it is taken out,
made into small cakes, and dried for use. A plantation employing 5
labourers contains 70,000-80,000 shrubs, and yields 40-50 _catties_ (of
1-1/3 lb.) of gambier daily.
Plantations were commenced in Singapore in 1829, and once numbered 800;
but owing to scarcity of fuel, abundance of which is essential to the
manufacture, and dearness of labour, the culture was fast declining
in 1866. In 1872, it had much recovered. It is largely pursued on
the mainland (Johore), and in the Rhio-Lingga Archipelago, S.-E. of
Singapore; on Bintang, the most northerly of the group, there were 1250
plantations of it in 1854. None is cultivated in Sarawak, though found
wild in many parts; the foreign export from Sarawak in 1879 had a total
value of 88,148 dol. The best kind is brought largely from Sumatra,
but is often adulterated with sago. The Rhio product is also thus
sophisticated, and rendered heavier by the Chinese purposely packing
it in baskets lined with wet _cajangs_, occasioning a loss to the
purchaser of about 30 per cent.
Singapore is the great emporium for gambier, and exported 34,248 tons
in 1871, 19,550 tons having been imported, chiefly from Rhio and the
Malay Peninsula. In 1876, the export increased to over 50,000 tons of
pressed block, and 2700 tons of cubes. In 1877, it fell to 39,117 tons,
owing to differences with the Chinese dealers concerning adulteration;
of this quantity, 21,607 tons were for London, 7572 for Liverpool, and
2345 for Marseilles. The United Kingdom imports in 1872 were 21,155
tons, 451,737_l._, almost all from the Straits Settlements; in 1880,
they were 26,061 tons, 461,781_l._, from the Straits, and 352 tons,
6468_l._, from other countries; total, 26,413 tons, 468,249_l._ Our
re-exports in 1880 were:--2487 tons, 48,507_l._, to Holland; 1591 tons,
31,542_l._ to Germany; 1137 tons, 23,694_l._, to Russia; 594 tons,
12,026_l._, to other countries; total, 5809 tons, 115,769_l._ The
approximate London market values are 15_s._ 6_d._-21_s._ 6_d._ a cwt.
for block, 18-24_s._ for pressed cubes, and 23-27_s._ for free cubes.
=Hemlock.=--The bark of the hemlock or hemlock spruce (_Abies
canadensis_), of Canada and the United States, contains nearly 14 per
cent. of tannin. The stripping of the bark commences in the southern
parts of the United States in spring, and lasts during April-May;
in New York, Michigan, and Wisconsin, the season is June-July; and
farther north, it is still later. It is said that the best product is
obtained farthest south. The destruction of the hemlock forests is fast
approaching. Within the last 25 years, the preparation of an extract
from the bark, containing 18-25 per cent. of a deep-red tannin, giving
considerable weight and firmness to leather, has superseded the export
of crude bark. One mode of preparing the extract is as follows:--The
bark in pieces 1/2-1 in. thick, and several inches long, is soaked for
about 15 minutes in water at 200° F. (93° C.); it is then fed into
a hopper, which conducts it to a 3-roller machine, something like a
sugar-cane mill, through which it passes, coming out lacerated and
compressed; it next falls into a vat of hot water, where it is agitated
by a wheel, that the tannin from the crushed cells may be dissolved
in the water; hence it is raised by a series of buckets on an endless
chain, somewhat in the manner of a grain-elevator, to another hopper,
whence it is fed to another 3-roller mill; here it receives its final
compression, and comes out in flakes or sheets, like coarse paper, and
almost free from tannin. The buckets are made of coarse wire, that the
water may drip through during the elevation. In order to avoid the
blackening action of iron, wherever this metal will come into contact
with the solutions it is thickly coated with zinc. The solution is
evaporated to a solid consistency, generally by vacuum-pans. About
2 tons of bark are represented by 1 bar. (of less than 500 lb.) of
extract. The chief makers are A. S. Thomas, Elmira, N.Y.; S. Brown &
Co., New York; Canada Tanning Extract Co., St. Leonard and Bulstrode;
J. Miller & Co., Millerton, New Brunswick. The total production is
probably over 10,000 tons annually, ranging in value between 14_l._ and
20_l._ a ton. Our imports are included in barks and extracts.
=Kino= (Fr., _Kino_; Ger., _Kino_).--The term "gum kino" is applied
to a class of astringent extracts of varied origin, none of which can
accurately be called either resins or gums.
[Illustration:
Pl. II.
_E. & F. N. Spon, London & New York._ "INK-PHOTO" SPRAGUE & CO. LONDON.
REMOVING THE HAIR; SCRAPING AND CLEANING THE SKINS.]
(1) _East Indian or Amboyna Kino._--This is obtained from _Pterocarpus
Marsupium_, a common tree in the central and southern parts of the
Indian peninsula, and in Ceylon; and a liquid kind from _P. indicus_,
of South India, Burma, Malacca, Penang, the Andamans, and Malaysia.
The collection of the juice is effected in the following manner. A
perpendicular incision, with lateral offshoots, is made in the stem of
the tree when blossoming has set in, and a receptacle is placed at the
foot of the incision. The exuding juice appears like red-currant jelly,
but it soon thickens by exposure to the air, and when sufficiently
dried, is packed into wooden boxes for exportation. It is one of the
reserved timber-trees of the Government forests in Madras, and its
juice is collected by natives, who pay a small fee for the permission.
The hardened juice consists of blackish-red, angular, pea-like grains,
partially soluble in water, almost entirely in spirit of wine of sp.
gr. 0·838, readily in caustic alkaline solutions, and largely in a
saturated solution of sugar. The liquid kino produces a very inferior
article on drying. The annual collection of kino in Madras probably
does not exceed 1-2 tons. Its approximate London market value is
60-150_s._ a cwt. It is employed medicinally, and in the manufacture
of wines, and might be employed as a source of tannin in dyeing and
tanning, if sufficiently cheap.
(2) _Butea, Bengal, Palas or Dhak Kino._--This variety is afforded by
the _palas_ or _dhak_ tree (_Butea frondosa_), common throughout India
and Burma, and affording a dyestuff, and a fibre, as well as by _B.
superba_ and _B. parviflora_. During the hot season, there issues from
natural fissures and from wounds made in the bark of the stem, a red
juice, which quickly hardens to a ruby-coloured, brittle, astringent
mass. It occurs in small drops or tears, and in flat pieces which have
been dried on leaves, and is almost always mixed with bark-fragments.
It is transparent, freely soluble in cold water, and does not soften in
the mouth. It is unknown in European commerce, but is employed in India
as a substitute for the kind first described.
(3) _African or Gambia Kino._--This is derived from _Pterocarpus
erinaceus_, a native of Tropical West Africa, from Senegambia to
Angola. The juice exudes naturally from fissures in the bark, but more
abundantly from incisions, and soon coagulates to a blood-red and
very brittle mass, known to the Portuguese of Angola as _sangue del
drago_ ("dragon's-blood"). It is practically undistinguishable from
the officinal kind first described, but is not a regular article of
commerce.
(4) _Australian, Botany Bay, or Eucalyptus Kino._--Several species of
_Eucalyptus_ afford astringent extracts, those from the "red," "white,"
or "flooded" gum (_E. rostrata_), the "blood-wood" (_E. corymbosa_),
and _E. citriodora_, being quite suitable for replacing the officinal
kind. It is chiefly obtained by woodcutters, being found in a viscid
state in flattened cavities in the wood, and soon becoming inspissated,
hard, and brittle. Minor quantities are procured in a liquid state by
incising the bark of living trees, forming a treacly fluid yielding 35
per cent. of solid kino on evaporation. It is imported from Australia,
but there are no statistics to show in what quantity.
=Mimosa- or Wattle-bark.=--The bark of numerous species of _Acacia_,
natives of Australia, contains considerable percentages of deep-red
mimo-tannic acid, which forms a hard and heavy tannage if used strong,
though soft upper-leathers may be tanned with it in weak liquors. The
chief kinds are as follows:--The common wattle (_Acacia decurrens_),
including its variety _A. mollissima_, is known also under the names of
green, black, and feathery, but must not be confounded with the silver
wattle (_A. dealbata_), though but doubtfully a distinct species. The
bark is obtainable in vast abundance, and is much used by tanners. The
trees are stripped in September and the 2 or 3 months following, and
the bark, being allowed to dry, is then in a marketable condition. This
tree, which grows in the uplands, affords a larger percentage of tannin
than the silver wattle.
Blackwood or lightwood (_A. melanoxylon_) yields tanners' bark, which,
is inferior, however, to that from _A. decurrens_. The bark of _A.
penninervis_ yields of tannic acid 17·9 per cent., and of gallic acid
3·8 per cent. The bark of the native hickory (_A. suppurosa_) yields of
tannic acid 6·6 per cent., and of gallic acid 1·2 per cent.
The bark of _A. saligna_, of South-Western Australia, is much used
by tanners, as it contains nearly 30 per cent. of mimo-tannin. _A.
harpophylla_, of South Queensland, furnishes a considerable share
of the mercantile wattle-bark for tanning purposes. The bark of _A.
lophantha_ contains only about 8 per cent. of tannin.
The broad-leaved or golden wattle (_A. pycnantha_), of Victoria and
South Australia, deserves extensive cultivation. It is of rapid growth,
will succeed even in sandy tracts, and yields seed copiously, which
germinates with the greatest ease. The perfectly-dried bark contains
about 25 per cent. of tannin. The aqueous infusion of the bark can
be reduced by boiling to a dry extract, which in medicinal and other
respects is equal to the best Indian cutch. It yields approximately
30 per cent. of tannin, about half of which, or more, is mimo-tannic
acid. Probably no other tanning plants give so quick a return in
cultivation as the _A. pycnantha_ and _A. decurrens_ of Australia. The
latter varies in its proportions of tannin from 8 to 33 per cent. In
the mercantile bark, the percentage is somewhat less, according to the
state of its dryness, it retaining about 10 per cent. of moisture. The
bark of the silver wattle (_A. dealbata_) is of less value, often even
fetching only half the price of that of the black wattle. The bark
improves by age and desiccation, and yields 40 per cent. of tannin,
rather more than half of which is tannic acid.
Amongst all the kinds, the bark of the broad-leaved wattle is
considered the most valuable, containing the greatest quantity of
tannin; that of the silver wattle is not so valuable, being deficient
in tannin; the black wattle is considered the most productive species;
it can be barked at 8 years of age, and will produce 40-60 lb. dried
bark, and full-grown trees will yield 100-150 lb. per tree.
The cultivation of wattles for commercial purposes has till now
remained undeveloped; but no doubt, as soon as it is understood, the
utilisation of many acres of land lying waste, or which have already
been exhausted and rendered unfit for the growth of cereals, will
be effected by the cultivation of the wattle. It requires so little
attention as to make it very profitable, and wattle-growing and grazing
can be combined satisfactorily. After the first year, when the young
trees in the plantation have reached the height of 3-4 ft., sheep can
be turned in.
Wattles grow in almost any soil, even the poorest, but their growth
is most rapid on loose sandy patches, or where the surface has been
broken for agricultural purposes. When the soil is hard and firm,
plough furrows should be made at a regular distance of 6-8 ft. apart,
into which the seeds are dropped. The seed should be sown in May,
having been previously soaked in hot water, a little below boiling
temperature, in which they may be allowed to remain for a few hours.
The seed should be dropped at an average distance of 1 ft. apart along
the furrow, in which case, about 7200 seeds would suffice for one acre
of land. The seed should not be covered with more than about 1/4 in. of
soil.
On loose sandy soil, it might even be unnecessary to break up the
soil in any way; the furrows may be dispensed with, and the seed sown
broadcast after the land is harrowed. After the plants have come up,
they should be thinned so that they stand 6-8 ft. apart. When the
young trees have attained the height of 3-4 ft., the lower branches
should be pruned off, and every effort afterwards made to keep the
stem straight and clear, in order to facilitate the stripping, and
induce an increased yield of bark. It is advisable that the black and
broad-leaved should be grown separately, as the black wattle, being
of much larger and quicker growth, would oppress the slower-growing
broad-leaved one. Care should be taken to replace every tree stripped
by re-sowing, in order that there should be as little variation in the
yield as possible. The months of September-December, in Victoria, are
those in which the sap rises without intermission, and the bark is
charged with tannin. Analysis proves that the bark from trees growing
on limestone is greatly inferior in tannin to that obtained from other
formations, differing 10-25 per cent.
The estimated expenditure on a wattle-bark plantation of 100 acres
during 8 years is:--
£ _s._ _d._
Rent of 100 acres for 8 years at 6_s._ per acre per annum 240 0 0
Ploughing 100 acres in drills 10 ft. apart 25 0 0
Sowing wattles and actual cultivation, including cost
of seed 37 10 0
Supervision for 8 years (nominal), say 10_l._ per annum 80 0 0
Pruning the trees, taking off useless wood (necessary
for 2 years), 10_s._ per annum 50 0 0
Incidental and unforeseen expenses 27 10 0
Interest on the whole amount expended during 8 years 240 0 0
─────────────
700 0 0
Actual cost of stripping and carting, as shown below 1515 0 0
─────────────
£2215 0 0
─────────────
The receipts derivable from a wattle plantation of 100 acres,
planted in the manner proposed, would be:--
£ _s._ _d._
Each acre planted with wattles, 10 ft. apart, would
carry 400 trees, and at end of 5th year trees would
yield say 56 lb. matured bark: stripping only
every 3rd tree, 332 trees would be obtained off
100 acres: this, at 4_l._ per ton, would give for
1st stripping 1332 0 0
In the 6th or following year, a similar number of
trees would be stripped: the bark having increased
in weight (say 14 lb.), the increased yield of 2nd
stripping would be 400 tons at 4_l._ per ton 1600 0 0
In the 7th year, the remaining trees would be
stripped, from which a still greater increase would
be obtained, say 480 tons at 4_l._ per ton 1920 0 0
Total yield of bark 4852 0 0
The cost of stripping would not exceed 15_s._ per ton,
on account of the facilities presented by the
regularity of the trees, while carting would represent
another 10_s._ per ton: these combined
charges would be 25_s._ per ton, and on 1215 tons,
would be 1515 0 0
─────────────
Leaving a clear profit on the 100 acres of £2637 0 0
─────────────
The exports of mimosa-bark in 1876 were 11,899 tons from Victoria,
4758 from South Australia, and 1735 from Tasmania. Later returns are
included in barks, p. 39. Shanghai imported 7038 _piculs_ (of 133-1/3
lb.) in 1879. The approximate London market values of mimosa-bark
are:--Ground, 6-13_l._ a ton; chopped, 5-12_l._; long, 5_l._-9_l._
10_s._ A very superior extract has been made from this bark.
=Myrobalans or Myrabolams.=--The fruits of several species of
_Terminalia_ constitute the myrobalans of commerce; they are chiefly
_T. Chebula_ and _T. Bellerica_, natives of India, the former being
a tree 40-50 ft. high, and esteemed for its timber also. The fruits
contain 30-35 per cent. of gallotannic and ellagitannic acids,
producing a soft and porous tannage, and good samples giving a
bright-yellow colour. The tannin exists in the pulp, and is absent from
the very hard "stone." The dried fruits are known locally as _har_,
_harra_, or _bahera_, and are used commonly for dyeing, but not for
tanning.
Our imports of myrobalans in 1880 were:--238,151 cwt., 121,465_l._,
from Bombay and Sind; 115,670 cwt., 51,339_l._, from Madras; 11,020
cwt., 4717_l._, from Bengal and Burma; 3520 cwt., 1402_l._, from other
countries; total, 368,361 cwt., 178,923_l._ Our re-exports in 1880
were 8015 cwt., 4328_l._, to Germany; 16,127 cwt., 8515_l._, to other
countries; total, 24,142 cwt., 12,843_l._ The approximate London market
values of myrobalans are 7-14_s._ a cwt. for good, and 5-10_s._ for
common. Shanghai imported 4403 _piculs_ (of 133-1/3 lb.) in 1879.
=Oak-barks= (Fr., _Écorces de Chêne_; Ger., _Eichenrinden_).--The barks
of several species of oak have valuable tanning properties. They are
chiefly:--The common oak (_Quercus Robur_, varieties: _sessiliflora_,
Ger. _Traubeneiche_; _pedunculata_, Ger. _Stieleiche_), which is of
even greater importance as a timber-tree; the cork-oak (_Q. Suber_);
the evergreen oak (_Q. Ilex_); and the American chestnut-oak (_Q.
Castanea_). These barks are among the most esteemed tannins as regards
quality of leather, but are incapable of giving much weight, and from
their bulk are costly to handle, containing only 10-12 per cent. of
tannin (quercitannic acid). They give a reddish fawn-coloured leather,
and deposit a good deal of bloom, but yield little or no gallic acid.
The barks of the cork-oak and evergreen oak from Southern Europe,
are stronger and darker-coloured than English bark. The American
chestnut-oak contains a peculiar fluorescent principle like æsculin.
Our imports of unspecified barks for tanners' and dyers' use in 1880
were:--189,399 cwt., 101,108_l._, from Australia; 123,302 cwt.,
32,974_l._, Belgium; 57,232 cwt., 20,988_l._, United States; 22,100
cwt., 6030_l._, Holland; 18,648 cwt., 3676_l._, Italy; 16,151 cwt.,
6972_l._, Algeria; 22,669 cwt., 8838_l._, other countries; total,
449,501 cwt., 180,586_l._ Our imports of unenumerated bark-extracts in
the same year were valued at:--516,578_l._ from Holland, 92,654_l._
France, 30,187_l._ United States, 16,315_l._ British North America,
12,796_l._ Belgium, 13,769_l._ other countries; total, 682,299_l._ Our
re-exports of barks in 1880 were:--19,548 cwt., 10,348_l._, to Germany;
14,627 cwt., 7425_l._, France; 4555 cwt., 3041_l._, Holland; 10,304
cwt., 6080_l._, other countries; total, 49,034 cwt., 26,894_l._
With regard to cork-tree bark, James Gordon & Co., Liverpool,
obligingly write that very little comes to England, the great bulk
going direct to Ireland, where the consumption is large. The imports
at Liverpool in 1880 were 186 tons, average value 8_l._ per ton. Of
oak-bark, Hungary, in 1877, produced 25,000 tons, of which, 20,000
were exported to Germany for tanning purposes. The approximate London
market values of oak-bark are:--English, 12-16_l._ per load of 45 cwt.;
Foreign, tree, 5-8_l._ a ton; ditto, coppice, 6-8_l._ In 1879, Algiers
exported 12,660,047 _kilo._ (of 2·2 lb.) of tanning bark.
=Quebracho.=--The local name _quebracho_, contracted from
_quebra-hacho_ ("axe-breaker"), is applied to several South American
trees possessing hard wood, belonging to distinct genera. They are
chiefly as follows:--(1) _Aspidosperma Quebracho_, the _quebracho
blanco_, a tree growing in the province of Catamarca, Argentine
Republic; (2) _Loxopterygium_ [_Quebrachia_] _Lorentzii_, the
_quebracho colorado_, most prevalent in the province of Corrientes, the
wood and bark of which come largely into commerce as tanning materials;
(3) _Iodina rhombifolia_, the _quebracho flojo_, whose wood and bark
are mixed with those of No. 2; (4) _Machærium fertile_ [_Tipuana
speciosa_], the _tipa_, which affords both wood and bark of less
tanning value than No. 2. It would seem that the wood and bark of No.
2 are by far the most largely employed, containing 15-23 per cent. of
a bright-red tannin. The wood and an extract from it are imported into
Europe.
From information kindly furnished by James Gordon & Co., and Haw &
Co., of Liverpool, it appears that the imports of quebracho-wood into
Liverpool in 1880 were 200 tons, value about 4_l._ 10_s._ a ton; and of
quebracho-bark, about 20 tons, none of which had been sold.
=Sumach or Shumac= (Fr., _Sumac_; Ger., _Gerbersumach_,
_Schmack_).--The commercial term "sumach" is applied to the dried
leaves of a number of South European and American tannin-yielding
plants. These are chiefly as follows:--In Sicily, the European or
tanning-sumach (_Rhus Coriaria_); in Tuscany, _R. Coriaria_, often
adulterated with leaves of _Pistacia lentiscus_; in Spain, several
_Rhus spp._, the products being divided into 3 kinds--Malaga or Priego,
Malina, and Valladolid; in the Tyrol, the smoke-tree or fragrant or
Venetian sumach (_R. Cotinus_); in France, _Coriaria myrtifolia_,
divided into 4 sorts--_fauvis_, _douzère_, _redoul_ or _redon_, and
_pudis_; in Algeria, Tezera sumach (_R. pentaphylla_), used by the
Arabs for making morocco-leather; in North America, the smooth or
white sumach (_R. glabra_), the Canadian sumach (_R. canadensis_), the
staghorn sumach (_R. typhina_), and the dwarf or black sumach (_R.
copallina_). These are found growing wild in the countries indicated,
and are further subjected to cultivation in some districts, notably
in Sicily. _R. glabra_ and _R. copallina_ are recommended chiefly for
extended cultivation in the United States.
The soil usually chosen for cultivation of the plants is poor and
light; but a much larger crop of leaves can be secured from strong,
rich, deep soils, and it is generally admitted that the product in the
latter case is also better. In Italy, limestone soils are considered
to be especially suited to this culture, but the American varieties
appear to be well adapted to sandy and clay soils as well. The primary
requisite in a soil is that it shall be well drained, the presence
of stagnant water about the roots being exceedingly prejudicial. To
prepare the soil for planting, it is ploughed as deeply as possible,
and laid out in rows about 2 ft. apart. In Italy, small holes are made
about 2 ft. long, 7 in. wide, and 5 in. deep, and a plant is inserted
at each end. A more convenient method would consist in marking the
field in shallow furrows in one direction 2 ft. apart, and then, with
a heavy plough, tolerably deep furrows the same distance apart as, and
at right angles to, the first. A plant may then be placed in the deep
furrows at each intersection, the furrow again filled with the plough,
and the earth pressed about the plant with the foot. If this were done
in early spring-time, as soon as the earth is sufficiently dry to be
conveniently worked, there can be no doubt that it would be successful,
while it would certainly involve little cost. Plants are generally
propagated from the young shoots which form each year about the base of
an older plant, but may also be produced from cuttings made from young
well-ripened wood, rooted by setting in a nursery or in frames, as in
the propagation of grape-vines from cuttings. This latter method is
scarcely ever required, however, when the cultivation has been started.
Plants are also raised from seed, and seedlings are always found to
be strong, vigorous, and thoroughly hardy; but on account of the
greater time and labour involved in their production, this method of
propagation has not received extended application. The first-mentioned
generally gives the quickest, and probably most satisfactory results.
In selecting plants from any source, there are certain points to be
observed:--(1) The shoots should come from young vigorous plants; (2)
they should be over 1 ft. long; (3) those with large roots and few
rootlets should be rejected; (4) those having white roots, covered with
a fibrous, white, silky down, are also to be rejected, this being an
indication of the presence of a very injurious subterranean parasitic
fungus, capable of destroying the entire crop; (5) a good shoot is
straight, at least 1/2 in. diam., 18 in. long, furnished with numerous
buds close to each other, root short, but covered with rootlets. Shoots
for planting may be collected in autumn, after the leaves have fallen,
and be preserved in a nursery until spring; or this may be done in
early spring, when the ground is very moist and soft. In either case,
care should be observed that the rootlets are not injured by drying, or
from any other cause.
The culture to be given the plant is somewhat similar to that required
by Indian corn: the earth about it should be kept tolerably mellow
and free from weeds, and such conditions can probably be maintained
to a degree sufficient for sumach, by working several times during
the growing season with a cultivator, and passing through the rows
occasionally with a plough. All this work is not absolutely necessary
to the life of the plant, but its vigour, and consequently its yield in
leaves, may be considerably increased and strengthened thereby. After
the first year, the number of operations may be diminished, but they
should always be sufficient to keep the ground free from weeds and
grass.
Shortly after planting, and when the plant is well set, the stock is
pruned to a length of 6-8 in., when the plant is left to assume any
form, and is no further pruned except by the process of collecting the
leaves, unless hand-picking is resorted to; in such case, after the 2nd
year, pruning takes place each year in the fall or winter, the plant
being reduced to a height of 6-10 in. After the 3rd year, the plant
begins to produce the shoots from about its base, already mentioned;
these, if not needed for new plantations, should be removed each year,
for if left to develop, they weaken the plant. If not removed during
the summer, the operation should without fail be effected during the
fall or winter.
The 1st crop of leaves may be secured during the year following that
of planting. This develops and matures somewhat later than that from
older plants, and in Italy it is not collected until the end of August
or the 1st of September; but there are reasons for believing that in
the United States, especially in the Northern States, the collection of
leaves from native varieties should be made much earlier, because the
summer is much shorter, and the habits of the varieties grown differ
from the Sicilian. Macagno has shown (Chem. Soc. Journ., xxxviii., p.
733) that the leaves from the upper side of the branches contain much
more tannin than those below, and that especially in the lower leaves
the percentage of tannin is much higher in June than in August. All
the leaves, except the young and tender ones of the extremities of the
branches, are stripped off and placed in baskets, in which they are
carried to a threshing-floor, where they are spread out in thin layers
to dry. Here they must be frequently stirred and turned over, for which
purpose a fork with wooden prongs is employed. In the fall, when growth
is finished, and before the leaves have had time to become red, those
remaining on the extremities are collected. To this end, the branches
are broken just below the tuft of leaves, and the latter are allowed
to remain suspended from the branch by a piece of bark not detached,
and left in this condition until nearly or quite dry. They are then
collected and treated in the same manner as other leaves, but the
product obtained in this way is always of inferior quality.
After the 2nd year, crops of larger quantity and superior quality are
obtained, and the collection is made in a different way, and much
more frequently. The two methods followed in Sicily are (1) pruning,
and (2) defoliation. The first, which is the more ancient, but much
less costly, requires less care, and is simple and rapid; but it is
injurious to the future condition of the plant, and the quantity of
subsequent crops. The second, though slower, serves to better maintain
the vigour of the plant, and the uniform quantity of the crop from
year to year; in consequence, it reduces the necessity for frequent
renewal of stocks.
Harvest by pruning is carried on in Italy as follows. During May,
the lower leaves, which, from greater age, appear to have attained
full maturity, and may be in danger of loss from falling, are removed
in the same manner as described for collecting the leaves from
yearling plants. Toward the end of June, and during the course of
July, all branches bearing leaves are cut away, reducing the plant
to the principal stock: by this means, the crop is harvested and the
plant is pruned at the same time. But even in Sicily, the time for
this operation is limited to no absolute period, and varies with
the development of the leaf, as indicated by cessation of growth
and increase in size. In this condition, also, the leaves will have
acquired their deepest green colour, and attained their maximum weight
and best quality. It is further stated that while this time varies
according to locality, about Palermo it is never earlier than June nor
later than July. The harvest by pruning must always be made by men
accustomed to the work, and equal to the exertion required. Provided
with a pruning-bill, they cut off all leaf-bearing branches, collecting
them an the left arm, until each has cut as much as he can conveniently
carry, when he places the armful on the ground with the butts in the
direction of the prevailing wind, which, if tolerably strong, might
carry away some of the leaves if turned in the opposite direction;
finally, he presses down the branches with his foot, to make the heap
more compact, and leave less surface exposed to the wind and sun.
Another labourer deposits a second armful in the same place, presses it
with his foot in like manner, and the two deposits constitute a bundle.
At the close of the operation, there remain the young shoots which are
formed about the base of the plant, the leaves of which are not fully
developed, and consequently not fit for collection until at least 20
days later. After this time, they are removed by hand, care being
observed not to injure the buds, especially if the shoots are to be
used for stocks in the formation of plantations in the following year.
Defoliation, or collection by hand, is carried on whenever the leaf
may be fully developed and ripe, beginning at first with the lower
leaves, and continuing eventually to the ends of the branches. It takes
place at 3 different times during the season: the 1st in May, the 2nd
late in July or early August, and the 3rd in September. At the last
collection, the extremities of the branches are broken down, and the
leaves are allowed to dry before removal from the plant, as described
under collections of the 2nd year. In the application of this method,
the regular pruning is effected during the fall or winter, when the
plant is dormant, and under such conditions the operation becomes a
regenerative one, giving in this particular an advantage over the other
method, in which the pruning is effected in the summer when the plant
is in full vegetative activity, and so has a strongly deteriorating
influence. In both methods of pruning, care should be observed to leave
a long slanting section, upon which water will be less likely to settle
and promote decay.
The leaves collected by either method are dried in the open field where
they have grown, and when dried, are carried to a threshing-floor to
be beaten, or at once to the threshing-floor and dried there. In the
former, the operation is rather more rapid, but there is greater danger
of injury by rain, the effect of which is very deleterious, especially
if it fall upon the leaves when they are partially dried. The damage
resulting from this cause is less if the leaves are not lying upon the
ground, and are so arranged that the air may circulate freely about
and under them. In the pruning method, the leaves are dried upon the
branches and in the heaps where they are first deposited. Sometimes
they are turned, but generally it is considered better not to disturb
them until completely dried, and ready for transportation to the
threshing-floor. In this way, they are protected to a greater extent
from the action of direct sunlight, which is said to be injurious to
the quality of the product. When the leaves are collected by hand,
they are dried upon the threshing-floor, where they are spread in
thin layers, and stirred 3-4 times a day. They are then beaten with a
flail to separate the leaves from the branches and stems. If this be
done during the middle of the day, when the leaves are most thoroughly
dry and consequently brittle, they are reduced to small particles,
producing what is called "sumach for grinding." But if it be done in
the morning, or on damp days, when the air is charged with moisture and
the leaves are tough, they are separated from the stems more nearly
entire and less broken, and the product obtained is called "sumach for
baling." The stems remaining after the separation of sumach for baling
still retain small particles of leaves attached to them, and they are
therefore again beaten when perfectly dry for the production of a
low-grade sumach, called by the Italians _gammuzza_. The products are
classed as follows:--
Relative Market
Value.
Sumach for baling 2·5
" " grinding 2·3
" from yearling plants 1·5
" " ends of branches }
collected in autumn } 1·0
To prepare these different grades for ultimate consumption, they are
ground in mills similar to those employed for crushing olives, that
is, in which two large stone wheels follow each other, revolving upon
a circular bed, the whole construction being about the same as the
Spanish or Mexican _arrastre_. The sumach thus pulverised is passed
through bolting-screens, to separate the finer from the coarser
particles.
In Virginia, the leaves are collected and cured by the country
people, and sold and delivered to owners of mills for grinding. Their
particular object being to secure the largest possible quantity of
product at the lowest cost, little attention is given to the quality
obtained, or the manner of collecting. The most intelligent dealers
in the raw material urge upon collectors to observe the following
particulars:--The leaf should be taken when full of sap, before it
has turned red, has begun to wither, or has been affected by frost, to
ensure a maximum value for tanning purposes. Either the leaf-bearing
stems may be stripped off, or the entire stalk may be cut away, and
the leaves upon it allowed to wither before being carried to the
drying-shed; but care must be observed that they are neither scorched
nor bleached by the sun. When wilted, they are carried to a covered
place, and spread upon open shelving or racks to dry, avoiding the
deposit in any one place of a quantity so great as to endanger the
quality of the product by overheating and fermentation. Sumach should
be allowed to remain within the drying-house at least one month before
sending to the market; in case of bad weather, a longer period may be
required. When ready for packing for shipment, it should be perfectly
dry and very brittle, otherwise it is likely to suffer injury in
warehouses from heating and fermentation.
Buyers of sumach leaves for grinding depend largely upon colour for
the determination of the value; the leaves should, therefore, when
ready for market, present a bright-green colour, which is evidence that
they have suffered neither from rain after being gathered, nor from
heating during the process of drying. Leaves having a mouldy odour or
appearance are rejected. The Virginian crop reaches 7000-8000 tons, and
is collected at any time between July 1 and the appearance of frost.
There is an important difference in the value of the European and
American products. The proportion of tannic acid in the latter
exceeds that found in the former by 6-8 per cent., yet the former is
much preferred by tanners and dyers. By using Sicilian sumach it is
possible to make the finer white leathers, in great demand for gloves
and fancy shoes; while by the employment of the American product, the
leather has a disagreeable yellow or dark colour, apparently due to a
colouring matter, which, according to Loewe, consists of quercitrin and
quercetin, and exists in larger quantity in the American than in the
Sicilian.
The experimental results obtained by collecting sumach at different
seasons were:--
Per Cent. of
Tannic Acid.
Virginia, mixed, collected in June, gave 22·75
" " " July, 27·38
" _R. glabra_ " August, " 23·56
" _B. copallina_ " " " 16·99
Sicilian, _B. Coriaria_ " " " 24·27
It is evident, therefore, that in order to secure the maximum amount of
tannic acid, the sumach should be collected in July, but the colouring
matter of the leaves has an important influence upon the value of the
product. The leaves of the upper extremities of the stalks are always
richer in tannic acid than those of the base; and the increase of age
of the plant is accompanied by a general diminution of this acid. Yet
the collection of the crop should be delayed as long as possible,
because the diminution of tannin in the leaves will be abundantly
compensated for by the quality of the product.
Experiments upon the presence of colouring matters were made by
treating gelatine solutions, and gave the following results:--
Virginia, mixed, collected in June, gave A nearly white precipitate.
" " " July, " A decidedly yellowish-white
precipitate.
" _R. copallina_, " August " A dirty-yellow precipitate.
" _B. glabra_, " " " A very dirty-white
precipitate.
Fredericksburg mixed, " " " A dirty-yellow precipitate.
Sicilian " " " A slightly yellowish-white
precipitate.
It is therefore advised that for the purpose of tanning white and
delicately-coloured leathers, the collection should be made in
June; while for tanning dark-coloured leathers, and for dyeing and
calico-printing in dark colours, where the slightly yellow colour will
have no injurious effect, the collection be made in July. It appears
that for all purposes, the sumach collected after the 1st of August is
inferior in quality.
[Illustration: Fig. 8.]
Fig. 8 shows a mill for grinding sumach-leaves; it consists of a heavy
solid circular wooden bed _a_, 15 ft. diam., with a depression around
the edge _b_, a few inches deep and 1 ft. wide, for the reception
of the ground sumach from the bed, and 2 edge-rollers _c_, weighing
about 2500 lb. each, 5-6 ft. diam., and provided with numerous teeth
of iron or wood, thickly inserted. Most mills have to be stopped to
allow the unloading of the bed, but this delay is obviated by an
apparatus consisting of an angular arm _d_, attached to a scraper _e_,
and worked by a lever _f_, which passes through the hollow shaft _g_
and extends to the room above, where it terminates in a handle _h_.
The scraper carries the ground sumach to the opening _i_, whence it is
taken by an elevator to a revolving sieve or screen in a room above.
After screening, the sumach is packed in bags, 15 to the ton, being
always sold by that weight. The chasers and beds are inclosed in a
case or drum, and the grinding is done by the application of power to
the upright shaft _g_. The mills are fed from above. The packing is
sometimes done by machinery alone. The best mills cost about 600_l._
In Europe, and in some parts of the Southern States, sumach is still
ground by stones revolving on a stone bed, and the sifting is often
done by hand.
E. Coez & Co., St. Denis, near Paris, make a sumach extract. It is
concentrated to a syrupy consistence in a vacuum-pan, and keeps
well, exhibiting none of the acidity which is manifested by a simple
decoction of sumach leaves. Sumach contains 16-24 per cent. of
gallotannic acid, and is somewhat similar in tanning properties to
myrobalans, but paler in colour. It is principally used for tanning
morocco and other fancy leathers.
The district of Ancona yields 200 tons per annum of sumach, said to be
equal to and cheaper than the Sicilian, but mostly consumed locally.
Palermo exported of "ventilated" sumach to the United States 120,043
bags (14 = 1 ton) in 1877, and 50,085 in 1878, the average value being
14_l._ a ton. Trieste exported 7800 cwt. by land in 1877; in 1878,
the shipments to England were 16,600 _kilo._ (of 2·2 lb.), value 1328
fl. (of 2_s._), and in 1880, 91,800 _kilo._ 7344 fl. Rustchuk in 1880
exported 1400 tons, chiefly to Roumania and Austria. Our imports
in 1880 were 10,573 tons, 133,249_l._ from Italy, and 1047 tons,
12,416_l._, from other countries; total, 11,620 tons, 145,665_l._ The
approximate London market value is 15_s._-16_s._ 6_d._ a cwt. for
Sicilian, 10-11_s._ for Spanish.
=Valonia= (Fr., _Vélanèdes_; Ger., _Valonia_). This is the commercial
name for the large pericarps or acorn-cups of several species or
varieties of oak, chiefly _Quercus Ægilops_ and _Q. macrolepis_. The
former is found growing in the highlands of the Morea, Roumelia,
the Greek Archipelago, Asia Minor, and Palestine; the latter
constitutes vast forests in many parts of Greece, and especially on
the lower slopes of Taygetos, towards Ætylon and Mani (Laconia). Prof.
Orphanides, of Athens, alludes to a third species or variety called
_porto galussa_, which yields a superior kind of valonia, and named
by him _Q. stenophylla_. The chief localities of production in Asia
Minor are Ushak, Borlo, Demirdji, Ghiördes, Adala, Nazlü, Buldur,
Sokia, Balat, Troja, Aivalik, and Mytilene. The annual exports,
mainly from Smyrna, reach 600,000 _quintals_ (of 2 cwt.), value about
400,000_l._ In Greece, the production is chiefly centred in the
following districts: (1) The province of Lacedemonia, which afforded
10,000 cwt. in 1872; (2) the province of Gythium, in the lower part of
Mount Taygetos, which gave 60,000 cwt. in 1872; (3) the island of Zea,
which formerly yielded 30,000-40,000 cwt., lately reduced to 15,000
cwt. yearly; (4) Attica, especially the neighbourhood of Cacossalessi,
grows 3000-5000 cwt., shipped from Oropos, in the Strait of Chalcis;
(5) the island of Eubœa, whence about 1000 cwt. are shipped annually
at Bouffalo; (6) the province of Triphyllia raises 3000 cwt., which go
to Trieste, viâ Cyparissie; (7) the province of Pulos, especially the
commune of Ligudista, grows over 2000 cwt., despatched from Navarino to
Trieste; (8) the province of Achaia has a yearly crop of 30,000-40,000
cwt., shipped to Trieste from Courupeli and Caravostassi, between
Patras and Cape Papa; (9) the small towns of Anatolico and Astakos
(Dragomestre) collect the valonia of the eastern parts of Ætylon,
Acarnania, and Cravassaras (a port in the Gulf of Arta), and of all
the other western parts, to be sent to Trieste for shipment to England
and Italy. Ætolia and Acarnania furnish abundant crops, that of 1872
exceeding 100,000 cwt. The total area of the Greek valonia-yielding
forests is said to be about 13,000 _stremme_ (of 119-1/2 sq. yd.). The
total production in 1877 was estimated at 2,601,000 _quintals_ (of
2 cwt.); the greater part is exported, about 2/3 going to Austria,
and the rest to Italy and England. The proportions of tannic acid in
the valonia from different districts of Greece are said to vary as
follows: Patras, 19-28-1/2 per cent.; Gythium, 27-1/4-35-1/2; Zea,
12-1/4-25-1/4; Vonitza, 18-20.
In Turkey, the fruit ripens in July-August, when the trees are beaten,
and the fallen acorns left on the ground to dry. The natives afterwards
gather them, and transport them on camel-back to stores in the towns,
whence they go by camel and train to Smyrna, and are there placed in
heaps 5-6 ft. deep in large airy stores for some weeks, during which
the mass heats, and the acorn itself, which contains but little tannin,
and is used for feeding pigs, contracts and falls from the cup. This
incipient fermentation is attended with considerable risk; if carried
too far, a large proportion of the valonia becomes dark-coloured and
otherwise damaged. When ready for shipment, the heaps are hand-picked,
the best being reserved for the Austrian market (Trieste), and the rest
going to England. In some cases, the rubbish having been removed, the
remainder is known as "natural," and is thus exported to England.
In Greek commerce, three qualities are distinguished, _chamada_,
_rhabdisto_, and _charcala_. The _chamada_ (_camata_ and _camatina_
of Asia Minor) is the best; it is collected in April, before the
acorn is matured, hence the cup which encloses the acorn is small and
incompletely developed. The _rhabdisto_ is the second quality; it is
collected in September-October, and is distinguished by the fruit being
larger and riper; the name means "beaten," the fruits being beaten
down from the trees with sticks. After mid-October the collection
ceases, because the first rains cause the fallen fruit to ferment
or turn black, and they then take the name of _charchala_. They are
distinguished by the cups being completely open, and containing no
acorns. They are considered much inferior, possessing little tannin.
[Illustration: Pl. IV.
_E & F. N. Spon, London &. New York._
"INK PHOTO". SPRAGUE & CO LONDON
REVOLVING, WASHING AND PRESSING MACHINES.]
Sometimes the acorn cup is attacked by a kind of honey-dew, which
deposits on the cup, and makes it very liable to heat when gathered,
the cup becoming very dark and deficient in tannin. The Turkish crop of
1875 was much damaged from this cause, many parcels reaching England in
an unsaleable condition. The cause of the disease is yet unknown; it
seems specially prevalent when the crop is large and the acorn fully
developed. A good sample of valonia should be composed of medium-sized
cups, with the rim or wall very thick, and the exterior spines small
and uniform. The cut or broken cup should show a bright-drab fractured
surface. Valonia contains 25-35 per cent. of a tannin somewhat
resembling that of oak-bark, but giving a browner colour and heavier
bloom. It makes a hard and heavy leather, and is generally used in
admixture with oak-bark, myrobalans, or mimosa-bark.
The Greek crop in 1880 was much damaged by the cold spring: It gave
600 tons in Acarnania and Ætolia, 650 in Cape Papa, and 1400 in Mania;
total, 2650 tons. Calamata and Messenia produced 115 tons, 1700_l._
Syra exported in 1879, 1174_l._ worth to Great Britain, 348_l._
Austria, 259_l._ Russia, 250_l._ Turkey, 178_l._ Egypt. Hungary
exported 942 tons in 1880. Adana shipped 9450_l._ worth in 1878; and
Dedeagatch, in the same year, 1,500,000 lb., 9000_l._ Musyna [Mersineh]
sent 670 tons, 3350_l._, to Italy, and 450 tons, 2250_l._ to Austria,
in 1879; and 480 tons, 2240_l._, to Italy, and 128 tons, 640_l._, to
Greece, in 1880. Our imports in 1880 were:--From Turkey, 30,391 tons,
471,637_l._; Greece, 2916 tons, 41,312_l._; other countries, 466 tons,
7105_l._; total, 33,773 tons, 520,054_l._ The approximate London
market values are:--Smyrna, 12_s._ 6_d._-20_s._ 6_d._ a cwt.; Camata,
15_s._-19_s._; Morea, 10_s._ 6_d._-18_s._
=Miscellaneous.=--Besides the foregoing tannins, which already occupy
prominent places in European and American commerce, there are many
others as yet of minor importance, but possessing qualities which may
bring them into note in the near future. They are as follows:--
_Abies Larix_ bark, the larch, contains 6-8 per cent. of a red tannin.
_Acacia albicans_ fruits, the _hiusache_ of Mexico, are used as
substitutes for gall-nuts, costing locally about 5_d._ a lb. _A.
arabica_, the _babul_ of India, yields a tannin which gives a nearly
pure-white precipitate with gelatine: the proportions are 12·55 per
cent, in trunk-bark, 18·95 in branch-bark, 15·45 in twig-bark. The
supply is unlimited. It works well with myrobalans. _A. Cebil_, the red
cebil of the Argentine Republic, contains 10-15 per cent. of tannin in
the bark, and 6-7 per cent. in the leaves; another variety, the white
cebil, contains 8-12 per cent. in the bark, and 7-8 per cent. in the
leaves. _A. Cavenia_, the _espinillo_ of the Argentine Republic, has
33-34 per cent. of tannin in the fruit-husks. _A. penninervis_ bark,
the "hardy" acacia of Australia, contains 18 per cent. of tannic acid
and 3-4 of gallic.
_Alnus glutinosa_ bark, the common alder, contains about 16 per cent.
of tannin.
_Cœsalpinia Cacalaco_ fruits, the _cascalote_ of Mexico, are very rich
in tannic and gallic acids, and are locally used for tanning.
_Comptonia asplenifolia_ leaves, the sweet-fern of the United States,
contain 9-10 per cent. of tannin.
_Coriaria ruscifolia_ bark, the _tutu_ of New Zealand, contains 16-17
per cent. of tannin.
_Elæocarpus dentatus_ bark, the _kiri-hinau_ of New Zealand, contains
21-22 per cent. of tannin. _E. Hookerianus_ bark, the _pokako_ of New
Zealand, contains 9-10 per cent. of tannin.
_Ephedra antisyphilitica_, on the tablelands of Arizona and Utah, gives
11-12 per cent. of tannin.
_Eucalyptus longifolia_ bark, the "woolly-butt" of Australia, contains
8·3 per cent. of tannic acid, and 2·8 of gallic. The "peppermint"-tree
contains 20 per cent. of tannic acid in its bark. The "stringy-bark"
(_E. obliqua_) gives 13-1/2 per cent. of kinotannic acid. The Victorian
"iron-bark" (_E. leucoxylon_) contains 22 per cent. of kinotannic acid,
but is available only for inferior leather.
_Eugenia Maire_ bark, the _whawhako_ of New Zealand, contains 16-17 per
cent. of tannin. _E. Smithii_ bark, the "myrtle"-tree of Australia,
contains 17 per cent. of tannic acid and 3-4 of gallic.
_Fuchsia macrostemma_ root-bark is thin, brittle, and easily exhausted;
it contains about 25 per cent. of a bright-red tannin, which has been
successfully tried. It is the _churco_ bark of Chili, which, however,
is attributed by the Kew authorities to _Oxalis gigantea_.
_Inga Feuillei_ pods, the _pay-pay_ of Peru, contain 24 per cent. of an
almost colourless tannin.
_Laurus Peumo_ rind is used in Chili for tanning uppers.
_Malpighia punicifolia_ bark, the _naucite_, or _manquitta_ bark of
Nicaragua, contains 20-30 per cent. of a very light-coloured tannin.
_Persea Lingue_ bark is red-brown, soft, and easily exhausted by
water; it contains 20-24 per cent. of tannin, and much slimy matter
which promotes the swelling of the hides. It serves in South America,
especially in the Chilian province of Valdivia, for tanning Valdivia
leather. In Southern Chili are enormous forests of the tree. The
imported bark has given good results with heavy leathers.
_Phyllocladus tricomanoides_ bark, the _kiri-toa-toa_ of New Zealand,
contains 23 per cent. of tannin.
_Polygonum amphibium_ leaves, an annual plant abundant in the Missouri
Valley, contain 18 per cent. of tannin, and can be mown and stacked
like hay. It is largely used in Chicago tanneries, and said to give a
leather which is tougher, more durable, of finer texture, and capable
of higher polish, than that tanned with oak-bark.
_Punica Granatum_ fruit-rind, the pomegranate, contains about 13·6
per cent. of a tannin like myrobalans, and a considerable quantity of
starch; the tannin is greatest in the bitter kind, which is used for
preparing morocco leather; the root-bark also is rich in tannin.
_Rhizophora Mangle_ bark, the mangrove, of Venezuela, contains 24-30
per cent. of deep-red tannin, if obtained from young stems; samples
from the West Indies have given 11·94 per cent., probably by the
gelatine process; two samples from Shanghai, by Löwenthal's improved
method, gave respectively 9·8 and 9·5 per cent. calculated as oak
tannin, and 71·96 and 78·52 of woody fibre. Guayaquil exported 9328
cwt. of the bark to Peru in 1879.
_Tecoma pentaphylla_ bark, the _roble colorado_ of Venezuela, contains
27 per cent. of tannin, accompanied by a soluble orange-red colouring
matter.
_Wagatea spicata_ pods contain 15 per cent. of tannic acid. The plant,
a scrambling shrub, is a native of the Concans.
_Weinmannia racemosa_ bark, the _tawhero towai_, or _kamai_ of New
Zealand, contains 12-13 per cent. of tannin.