Stains

is to come, we must, before dunging the goods, apply a little of the lime juice, or tartaro-oxalic acid discharge paste, to the place. If, on the contrary, the stains are not perceived till after the madder ing, we must then apply to it first a strong solution of chloride of lime with a pencil, next a solution of oxalic acid mixed with a little muriatic with another pencil, and immediately afterwards wash with water. Every madder stain will be effaced by this means. Rust stains are removable by a mixture of oxalic and muriatic acids. Indigo stains by the combined action of chloride of lime and muriatic acid. Topical yellow stains, or yellow dyes, by the same combination. Metallic greens and Scheele’s green by the acid alone. Chrome green, and Pru ian blue. The blue may be taken out by a caustic alkali; after which the goods must be washed: the residuary rust stain may be removed by the mixture of oxalic and muriatic acids. The above methods refer to cotton and linen. The stains on silk and woollen stuffs should be removed before fixing the colours by the soap boil; which may generally be done by scratching with the finger, with the aid of a little water. For a direct calico green, see oxide of Chrome . Mr. Hudson, of Gale, near Rochdale, obtained a patent, in December, 1834, for a mechanism which furnishes a continual and regular supply of colour to the sieve or tear ( tiré , Fr.) into which the printer has to dip his block, for the purpose of receiving the colour about to be transferred to the fabric in the operations of printing calicoes or paper hangings. The contrivance consists in a travelling endle web, moved by power, which, by pa ing progre ively from the colour vat over the diaphragm, brings forward continuously an equable supply of the coloured paste for the workman’s block. IMG:4147767755307473660_illo0243.png:Hudson Fig. 251. represents the construction of this ingenious apparatus, shown partly in section. a a is a ve el of iron, supported upon wooden standards b b , over the upper surface of which ve el a sheet or diaphragm, c c , of oiled cloth, or other suitable elastic material, is distended, and made fast at its edges by being bent over a flange, and packed or cemented to render the joints water-tight. A vertical pipe d is intended to conduct water to the interior of the ve el a , and, by a small elevation of the column, to create such upward pre ure as shall give to the diaphragm a slight bulge like the swimming tub. An endle web, e e e , pa ing over the surface of the diaphragm, is distended over three rollers, f g h , the lower of which, f , is in contact with the colour-roller i in the colour-trough K . On the axle of the roller i a pulley wheel is fixed, which allows the roller to be turned by a band from any first mover; or the roller may receive rotatory motion by a winch fixed on its axle. On this said axle there is also a toothed wheel, taking into another toothed wheel on the axle of the roller f ; hence, the rotation of the colour-roller i in the one direction will cause the roller f to revolve in the opposite, and to carry forward the endle web e e e , over the elastic diaphragm, the web taking with it a stratum of colour received from the roller i , evenly distributed over its surface, and ready for the printer to dip his block into. The axles of the rollers f and g turn in stationary bearings; but the axle of h is mounted in sliding nuts, which may be moved by turning the screws m , for the purpose of tightening the endle web. The axle of the colour-roller i turns in mortises, and may be raised by screws n , in order to bring its surface into contact with the endle web. To prevent too great a quantity of colour being taken up, the endle web pa es through a long slit, or parallel aperture, in a frame o , which acts as a scraper or doctor, and is adjustable by a screw p , to regulate the quantity of colour carried up. The contents of the ve el a , and of the colour-trough K , may be discharged when required by a cock in the bottom of each. See Paper Hangings , for the Fondu style.