MISCELLANEOUS NOTES. A NOVELTY IN COTTON DYEING. John W. Fries, a practical cotton and woolen manufacturer of Winston-Salem, N. C., has spent several years in working out processes and machines which constitute a veritable revolution in the art and practice of dyeing. Patents have been taken out in this and foreign countries, and we are informed that others have been applied for. As a manufacturer of coarse goods, the selling price of which is notoriously near to the raw material, Mr. Fries was long impressed with the excessive labor cost involved in the repeated handling of yarns and cloth by old methods, and set himself to devise methods and machines, by which the material, taken dry as it would ordinarily go to the dyehouse, might be dyed, and if desired sized and finished, and delivered again without manipulation, and absolutely in one operation. For the basic dyes as contemplated in his earlier patents he uses acetate of lime or its equivalent with the color held in solution by free acid, which free acetic acid is driven off on drying, and leaves a precipitate of the color with basic acetate of lime, on the fiber; and provides for further fixing this precipitate if desired, by the use of common soap, which forms an insoluble lime soap. This method is well adapted to light and medium shades. In his later work, Mr. Fries sticks to the "one operation" idea, but otherwise follows an entirely different line, using the direct or substantive dyes, which are developed and fixed in an atmosphere of dry steam. By this method all shades are produced, from a mere tint of any color up to a full black. These machines can be advantageously used also with the new sulphur dyes, which are attracting so much attention in the technical world, and we predict that these sulphur colors are "the dyes of the future," when they shall come to be generally used in this way. As yet Mr. Fries' machines have been sold only for cotton chain dyeing, but his patents contemplate their use on all kinds and forms of textile materials, and a machine for coloring cloth is now in process of construction. INDIGO. Dr. M. Liebert. After the constitution of indigo had been established, the chemists-who by that time had learned to build up by synthesis, from their component parts, complicated chemical bodies which were primarily known as vegetable matter-naturally began to feel their way to building up this indigo blue synthetically. With these researches the name of Adolf von Baeyer, of Munich, will be coupled for all time as the great pioneer of the synthesis of indigo. He succeeded, in 1878, by a series of more or less complicated reactions, in converting oxidol into isatin. Isatin, on the other hand, was easily converted into isatin-chloride, and this, when reduced, yielded indigo. However, a more beautiful synthesis than the one just explained was discovered by Baeyer two years later. He used cinnamic acid as his starting material, and converting this first into its nitro-compound, and, by subsequently brominating the latter, produced first the di-bromide of this acid, then ortho-nitro-propiolic acid, and, finally, isatin and indigo blue. |