LEATHER (VARNISHED FRENCH, MAN UFACTURE OF). This process consists of two operations :—First, the preparation of the skin, described under the head fanning; and, second, the varnishing of the leather thus dressed. In the prepa ration of the leather, linseed oil, made to dry quick by means of metallic oxides and salt, is employed as the basis. For each twenty-two gallons of linseed oil, twenty two lbs. of white lead and twenty-two lbs. of litharge are employed, and the oil boil ed with those ingredients until it has at tained the consistency of svrup. This preparation, mixed either with chalk, or ochres, is applied to leather by means of appropriate tools, and well worked into the pores ; three or four layers are applied in Succession, taking care to dry each layer thoroughly before the application of the next coating. Four or five coatings of the dried linseed oil, without the admixture of the earthy substances, are then given and the addition of very fine ivory black and some oil of turpentine is usually made to the oil. 'These coatings are put on very
thin, and when carefully dried the leather is rubbed over with fine pumice stone powder to render the surface perfectly smooth and even, for the reception of the .varnish. The varnish is composed as follows :—Ten lbs. of oil prepared as above, half a lb. of asphalt or Jewish bitu men, five lbs. of eopal varnish, and ten lbs. of turpentine. The oil and asphalt are first boiled together, the copal var nish and turpentine added afterward, and the mixture well stirred. Instead of as phalt, Prusian blue or Ivory black may be employed. This varnish must be kept in a warm place for two or three weeks before it is fit for use. The greatest pos sible care must be taken both before and during the application of the varnish to prevent the adherence of any dust to the leather. The leather, when varnished, must be put into drying stoves, heated to about 200 decrees or more, according to the nature of the leather and the varnish employed.