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 bated 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. (Spons' Encyclopedia.)

Without doubt, of all the manipulations that skins are subjected to in order to produce fancy leathers, that for the production of morocco leather is the most difficult and interesting. The discovery of the art is comparatively recent, and requires a thorough knowledge, not only of the action of the tannic acid upon the epidermis, but also of chemistry, for the preparation and application of the various colours. It was not until the end of the last century that a factory was established at Choisy (France) for the fabrication of morocco leather; the method employed remained for a long time a secret, it being more simple than the one mentioned by Dela-lande as existing at Morocco. The red colour that they gave the skins was found to be superior to the genuine article, could resist the astringent action of sumach for many days, and was unaltered by acids; in consequence of this, even at the present day the dyeing of the skins no longer takes place in the Oriental countries, but the skins are sent, under the name of Meschin leather, to be dyed and dressed in Europe. Little by little a variety of reddish colours were produced, but it was not until 1820 that the art of dyeing blue was discovered.

About the same year a new kind of morocco was made at Stras-burg, having a metallic appearance (obtained with a decoction of logwood and certain salts). After all the above had been accomplished, there were still other difficulties of great importance to be overcome. It was necessary to obtain rapid drying in all seasons. The delicate tints were easily altered by the rain; heat of an oven changed the colours; the only possible drying was in the open air. Fries and Fanler proposed ovens kept at a constant temperature by means of a ventilator.

Morocco leather is made of tanned goat-skins, and its manufacture is an industry in which Philadelphia can justly claim a superiority over any city in the Union; nearly three-quarters of the total number of skins imported are brought to that city to be converted into morocco. The climate and water seem to be well adapted for this purpose. This being a well-known fact, experts from other States and countries have come there to offer their services. The black colour is obtained with acetate of iron; as for the other colours, aniline dyes are made use of.

The number of skins utilized daily varies from 15 to 50 dozen, according to the size of the factory. They all arrive in a dry and hairy state, and are softened by soaking in water for several days treading them under the feet, and scraping on the fleshy side to produce evenness. They are then placed in lime-pits (these preliminary operations require great care). The hair is easily detached after one month's soaking, then they are scraped on the beam, after which they are placed in a milk of lime, and fleshed with a scraping-knife.

The vatting of the unhaired skins is more important in the manufacture of morocco than any other kind of leather, as a small quantity of lime will often be sufficient to destroy the action of the dye. The French understand the importance of this, and to ensure the skins being well washed after the vatting, they are placed in cylinders one-half filled with water, which revolve on a horizontal axis; afterwards they are frequently placed in a bath of lactic acid; in this manner the lime becomes soluble. The tanning now commences. Sumach in nearly every case is used. The skins are sewn together, and the necessary amount of tanning substance is placed in the interior of the sack thus formed. They are inflated with air, and are then sewn tightly to prevent any escape, and are thrown into a vat containing a shallow depth of a weak solution of sumach, and are made to float during 4 hours, being agitated occasionally in order to secure a uniform action of the sumach. (In England, instead of air, water is employed in the skins.) They are then piled one on the other, the pressure thus produced by their own weight being sufficient to force the tannin through all the pores of the skin.

This operation is again repeated, after which the bags are unstitched, scraped on the beam, and placed in the drying-room, which has a direct communication with the open air. When dry, they are again moistened, rubbed with a copper tool to make them smooth, and are again hung up to dry. The skins are now ready to be dyed, which can either be done in a dye-vat or with a brush.

The first takes place in a small trough large enough to hold one skin. The dye is at a temperature of 60°, and is about equal in quantity to the volume absorbed by one skin. They are continually moved to and fro. This dyeing operation is repeated several times, after which they are rinsed, stretched on boards, rubbed smooth, tacked round the edges, washed in water, and dried.

Then the brush is made use of. Two skins are placed together, and are rubbed exteriorly with a brush containing the mordant solution. The colour is applied afterwards in the same manner. The French method of dyeing red consists in sewing the skins flesh against flesh before tanning with sumach. (The mordant must be warm.) About 33 gr. of cochineal per skin are used.

As for other colours, the tanning takes place before the dyeing. The skins of the same colour, after being placed for a short time in the dye-vat, are piled one on the other, and are submitted to the action of a hydraulic press. In this manner the excess of dye-liquor is removed.

* The following table gives the chemicals made use of in dyeing skins in order to produce different colours: -

Dyeing In Vat

Colours obtained.

Chemicals made use of.

Prussian Blue.

1st. Diluted solution of nitrate of iron for 1 hour.

2nd. Warm bath containing yellow prussiate of potash and a little SO3

Scarlet.

1st. Mordant of chloride of tin and cream of tartar.

2nd. Extracted liquor of cochineal.

Purple.

Extract liquor of cochineal on the top of Prussian blue.

Bronze.

Strong extract of logwood and alum.

Dyeing With A Brush Applied Topically

Colour* obtained.

Chemicals made use of.

Black.

Solution of acetate of iron.

Crimson.

1st. Mordant of alum or tin salt.

2nd. Decoction of cochineal.

Puce.

1st. Mordant of alum.

2nd. Decoction of logwood.

Blue.

Solution of sulphate of indigo.

Olive.

1st. Mordant of a weak so-

lution of copperas.

2nd. Decoction of barberry

containing a little blue

bath.

Violet.

Consecutive application of a decoction of cochineal and weak indigo bath.

Skins are classified, and the finest are dyed with red. There are two kinds of morocco - the genuine and the imita-tion. The difference between the two is that the latter is obtained by the splitting of calf, sheep, and other skins, and is chiefly employed for bookbinding. The preparation of these skins is the same as the above, except after being stripped of their wool they are submitted to a powerful hydrostatic pressure to get rid of oleaginous matter, which would greatly interfere with the tanning. Dyed skins are enhanced by dressing, and the grain given. They are first rubbed on the hair side with linseed-oil, applied by means of flannel; then glazed by machinery, after which the peculiar appearance of the surface is given by rolling the skins on a table under a small weighted roller having a grooved face. (L. S. Ware in Polyt, Rv.)

Restoring Morocco Leather

Find some Judson's dyes the colour you require, and dilute for shade required. When dry, finish with glaire - i.e. the white of eggs whipped up and allowed to stand. The liquid is poured off, and this is the article required.