MOROCCO LEATHER.
Morocco leather is produced from goat-skins. Rough-haired or
"blue-back" seal-skins are also used, and produce an excellent article;
while an inferior description, called "French morocco," is produced
from sheep-skins. The skins are unhaired by liming in the usual way,
and are then baited with a mixture of dogs' dung and water. The tanning
is done chiefly with sumach, at first in paddle-tumblers, and then in
handlers, lasting about a month in all. Sheep-skins are usually tanned
through in about 24 hours, by being sewn up into bags, grain-side
outwards, and nearly filled with strong sumach infusion. A little air
is then blown in, to completely distend the skin, and they are floated
in a sumach bath, and kept moving by means of a paddle. After the
first day's immersion, they are thrown up on a shelf, and allowed to
drain; they are then again filled with sumach liquor; when this has
a second time exuded through the skin, they are sufficiently tanned,
and the sewing being ripped open, they are washed and scraped clean,
and hung up to dry, making what are called "crust-roans." The dyeing
is sometimes done by brushing on a table, grain-side upwards, but more
usually the skins are folded closely down the back, flesh-side inwards,
so as to protect it as much as possible from the influence of the
colour, and then passed through the dye-bath, which is now generally of
aniline colours. The original oriental method of manufacture for red
morocco was to dye with cochineal before tanning, and this is still
customary in the East, but is quite obsolete in this country. A grain
or polish is given to the leather, either by boarding, or by working
under small pendulum rollers, called "jiggers," which are engraved
either with grooves or with an imitation of grain. A well-cleaned
sumach-tanned skin is capable of being dyed in the finest shades of
colour; and this branch of the manufacture of leather has been brought
to great perfection.