LEATHER

(Germ, leder.) The prepared skins of animals. The principal object of the art of converting skin into leather is to render it strong and tough, durable, and often water-proof, and to prevent its destruction by putrefaction. The skins are first cleansed of hair and cuticle, and then impregnated either with vegetable tan and extract, as in the production, of what is called tanned leather, or with alum and other salts, as for tawed leather; these proce es are sometimes combined, and tanned leather often undergoes the further operation oi currying, or impregnation with oil. As instances of these different results, thick sole leather is tanned; white kid for gloves is tawed; the upper leather for boots and shoes is tanned and curried; and fine Turkey leather is tawed, and afterwards slightly tanned. Tanned Leather.— Tor thin skins which are afterwards curried, the hide is cleansed, and soaked for a day or two in water; it is then beamed, or stretched upon a solid half cylinder of stone, where it is cleared of adhering fat and flesh; it is then soaked for several dajs in a pit of lime and water, by which the hair and cuticle are so far loosened as to admit of being scraped off upon the beam; the hide is then washed and put into the tnasterins pit, which is a mixture of water and dung, — that of nens, pigeons, or dogs is pr<?ferred, cow or horse dung not being sufficiently putrescible. When the hide has here become soft and supple, it is again thoroughly cleaned, and submitted to the tanning liquor, which is at first used very weak, and gradually strengthened till the operation is complete: this requires from two to four montlis for calfskins, and from twelve to eighteen months for tliick ox and boar hides intended for strong sole leather; and the latter hides, instead of being limed and dunged, are generally, after having been cleaned in water, placed in heaps, where they begin to putrefy, and then tht hair may be removed without lime, which would be apt to render the skin hard and harsh. The further opening of the texture, so As to ftrepare it for tanning, is effected by immersion in a sour iquor of fermented rye or barley, or in weak sulphuric acid. [s. 661]