entered as rapidly as possible into the baths. Some workers acidify the wool first and chlorinate afterwards; others mix the bleaching powder and acid together, but this often leads to loss of chlorine, the effect of which is disagreeable to the workers, as chlorine gas is most unpleasant to breathe. Practice shows that 4 pounds good bleaching powder to 100 pounds of goods is about the minimum quantity to use that will give an unshrinkable effect. More may be used, but in this case there is a greater risk of producing two rather undesirable effects, that of imparting a yellow color to the wool fabrics and that of making them harsh. Much depends upon the quality of the wool being treated, and workers should ascertain for themselves the maximum amount of bleaching powder they can use without producing this yellowness; some recommend as much as 10 pounds to the 100 pounds of goods, but this is rather excessive. Any harshness may be removed by working for half-an-hour in a bath made of 125 pounds acetate of alumina, 18° Tw., and 250 gallons of water for 100 pounds of goods. This may be used cold, but the employment of heat, say 150° F., facilitates the action. After this bath the goods are well washed in water. It is well to pass the goods, after the washing process, through a weak bath of ammonia to neutralize any acid for the goods, after the chlorination treatment, have an acid reaction which makes them slightly harsh; the alkaline treatment softens them. THE DYEING OF INDIGO MLB ON WOOLEN YARN. For the dyeing of blues on woolen yarns Indigo MLB, applied in one or the other of the various hydrosulphite vats, is of very great service both when the indigo is used by itself or when the blue serves as a bottom for other colors. In preparing the vat with Indigo MLB 20 per cent. paste, a stock vat is first prepared from 44 pounds Indigo MLB 20 per cent. stirred with 1 gallons caustic soda 42° Tw., and 83 gallons of Hydrosulphite 0, or with 24 gallons hydrosulphite of soda. The hydrosulphite is prepared by mixing 10 gallons of bisulphite of soda 70° Tw., with 20 gallons of water, and with a paste of 10 pounds zinc dust and 1 gallons of water. The mixture should be well stirred, the temperature will rise a little but it ought not to be allowed to go much higher than 95° to 100° F. After standing one or two hours, the clear supernatant liquor is run off and mixed with milk of lime made from 10 pounds quicklime in 2 gallons of water. Stir the mixture well, then allow to stand for two hours, pour off the clear liquor and to every 10 gallons add pint of caustic soda 42° Tw. Store the hydrosulphite so made in well closed vessels. As this solution does not keep well it is advisable to use Hydrosulphite 0 Hoechst which is more stable. The stock vat, as made above, may be made of any quantity either larger or smaller than is given above. It should have a clear greenish yellow color and be free from any turbidity. If the color is green there is insufficient hydrosulphite; if yellow, too much; the remedy in both cases is obvious. If the liquor be turbid there is too little caustic soda. It is important to avoid the use of too much caustic soda as it has an unfavorable action on the wool fibre. The dye vat is made with the usual amount of water, and 1 gallon of hydrosulphite is added to each 500 gallons of the water in order to remove any oxygen the water contains that might act detrimentally on the indigo. Sufficient of the stock vat is then stirred well in and allowed to stand. The condition of the vat should be ascertained, as indicated above, and brought to the right state by addition of hydrosulphite or caustic soda, as may be required. In dyeing it is necessary to immerse the yarn below the surface of the liquor. This is effected by arranging the sticks on which the yarn is suspended to hang on rails running on the side of the vat. A better plan is to use bent iron sticks resting on the edges of the vats, as these are more handy to handle and work. The best temperature to work at is 100° to 110° F. The yarn is worked for twenty to thirty minutes, care being taken in working not to expose the yarn to the air. At the end of the time the yarn is taken out, well wrung out, and then hung in the air for the blue to properly develop. For pale blues one dip is enough; for deep shades two to three dips will be needed, oxidizing in the air between each. After the blue is fully formed, rinse the yarns in a weak sulphuric acid bath; this helps to develop the blue, and, at the same time, any risk of damage to the wool from the alkalinity of the bath is avoided. Pale sky blues can be raised without airing by rinsing off in a weak acid bath. As the various lots of yarns are run through the vat this becomes exhausted of indigo and must be replenished from time to time by additions of hydrosulphite stock vat and a little alkali. Pale shades require more alkali than deep shades. When deep shades are dyed, the amount of stock indigo vat to be added is about half of that originally added; with medium blues about one-third, and with pale tints one-fourth the starting quantities. Practice soon puts the dyer right as to the quantities to be added. At the end of a day's work, it is well to make up the vat again, add a little extra hydrosulphite and alkali, stir well and allow to stand till next morning, when the vat will be in good condition for working. Used in the manner given above, Indigo MLB 20 per cent. paste will be found to work excellently and give pure shades of blue.— Dyer and Calico Printer. DIRECT SILK PRINTING. The silk is de-gummed with about 30% of olive oil soap, then rinsed and finally soured (4% muriatic or a corresponding amount of acetic acid). In order to whiten the material, the silk may be bleached by sulphuring or in a slightly alkaline bath of peroxide of hydrogen; a treatment with phosphate of tin is used only with Dianil and a few other dyestuffs. Almost all colors, with the exception of indigo and sulphur dyestuffs, can be used for direct printing on silk, and they may be fixed without further assistants. Basic colors may be used without tannin, and certain mordant colors may be fixed without mordants; but in order to enhance the fastness to water and washing, either tannin or metallic salts are employed. It is important to dissolve the colors properly and select the most advantageous thickening to produce even results. Thickenings and mordants have also great influence upon the feel of silk. A surplus of mordant produces a harsh feel and certain thickening agents, like gum in the presence of chrome mordants, act detrimentally upon the lustre of the silk; additions of soap, oil, Turkey red oil, etc., to the printing pastes must also be avoided. The most general thickening ingredient is gum; for light colors Gum Senegal is the most advantageous. White and yellow dextrines, also British gum and tragacanth may be used, the tragacanth-starch thickening, however, is less frequently employed, as it requires much more washing; the same applies to certain British gums containing starch; and since many thickenings are liable to produce dull effects, it is advisable to always make trials with these thickenings first to ascertain their suitability for the required purpose. The thickening has also an influence upon the depth of the shade. British gum yields the darkest shades, for medium British gum, dextrine yellow and white or mixtures are used; for light shades Gum Senegal, yellow dextrine and burnt starch are preferable. The alizarine colors, fixed with chromium acetate, may be thickened with any of the above with the exception of gum, which tends to make the handle harsh; the tragacanth thickening may be used for all colors with the exception of those that require chrome mordants. The thickenings are either stirred into the color solution, or the dextrine, burnt starch or British gum are added to the color and the whole heated until the thickening is properly dissolved. The latter method is advantageous for colors which dissolve with difficulty. For 1000 parts of printing paste are used: For Light Shades.......540 parts Yellow Dextrine For Dark Shades.. .250 parts British Gum In preparing printing pastes ammonia is often added in order to keep certain colors (Patent Blue, Acid Violet, Silk Wool Black, Eosine, Chinoline Yellow, Nigrosine, etc.), better in solution. After printing, the silk is steamed for one-half hour in moist steam. Tannin colors are then passed through an antimony bath and washed. Pastes containing starch are washed in a lukewarm Diastafor bath in order to soften the material. Since many of the colors fixed on silk are fairly fast to soap, the goods are generally soaped after printing. In order to improve the handle, the goods are soured after rinsing. 20 parts Dyestuff FOR BASIC COLORS. 100 parts Acetic Acid 12° Tw.. 600 parts Senegal Gum 1:1 20 parts Tartar Acid 40 parts Acetic Acid Tannin Solution 1:1 220 parts Water 1000 parts FOR ACID COLORS, INCLUDING RESORCINE COLORS. 20 40 parts Dyestuff 330-310 parts Water 600 parts Senegal Gum 1:1 30 parts Glycerine 20 parts Tartaric Acid 1000 parts |