Lead, Tar′trate of. Syn. Plumbi tartras, L. Prep. By precipitating acetate of lead, by tartrate of ammonium, washing and drying.
LEAD DUST. Syn. Pulvis plumbi, Plumbum divisum, L. Prep. By melting new lead, adding bruised charcoal, mixing with violent agitation, which must be continued until the metal ‘sets,’ and then pounding and washing away the charcoal. Used by potters.
LEAD, GRANULATED. Prep. By melting new lead, and pouring it in a small stream from an iron ladle with a hole drilled in its bottom, into a pail of water. Used to make solutions and alloys.
LEAD, RED. See Red pigments.
LEAD, WHITE. See White pigment.
LEAD PYROPH′ORUS. See Pyrophorus.
LEATH′ER. Syn. Corium, Corius, L. Leather is the skin of animals which has been prepared by one or other of several processes adopted for the purpose, having the common object of preventing its spontaneous destruction by putrefaction, besides other objects, which are more or less peculiar to each variety of this useful substance.
Leather is only prepared on the large scale, and primarily either by the process of ‘TANNING’ or ‘TAWING,’ in the manner briefly described under these heads.
Curried leather is leather which has been tanned, and sold to the currier, who, after soaking it in water, and rubbing it to soften it, pares it even with a broad, sharp knife, rubs it with a piece of polished stone or wood, and, whilst still wet, besmears it with oil or grease (DUBBING), which gradually penetrates the leather as the moisture evaporates. It next undergoes the operation of ‘waxing,’ which consists of first rubbing it on the flesh side with a mixture of oil and lamp black; it is then ‘black-sized’ with a brush or sponge, and, when dry, is lastly ‘tallowed’ with a proper cloth, and ‘slicked’ upon the flesh side with a broad and polished lump of glass. Leather curried on the hair or grain side, termed ‘black on the grain,’ is blackened by wetting it with iron liquor, and rubbing it with an iron ‘slicker’ before applying the oil or grease. The grain is finally raised by the ‘pommel’ or ‘graining board’ passed over it in various directions.
Leather is dyed or stained by the application, with an ordinary brush, of any of the strong liquid dyes, in the cold or only gently heated, to the surface of the skin previously stretched on a board. The surface, when dry, is commonly finished off with white of egg and the pommel or smoothing stick. Bookbinders generally employ copperas water as a black