_For Wool._—The goods, well washed and soaked, are warmed gently in a bath containing, besides the dyestuff dissolved in plenty of water, a little sulphuric acid and a good deal of Glauber’s salt. Both acid and salt should be free from iron, or the shade will be dulled. The amount of acid to be used may vary between considerable limits without affecting the results. If too much is present, there is danger of injuring the feel and the lustre of the fibre. If there is not enough acid in the bath, the color will wash right out of the wool, as soon as it is rinsed. In general it is well to start with about one tablespoonful of dilute (30%) sulphuric acid for each gallon of dye-liquor and about twice that amount of Glauber’s salt. It is hard to tell just what is the function of the Glauber’s salt. It seems, however, to open up the pores of the wool in some way, and to make it dye more evenly and deeply. The bath is gently heated, with constant stirring of the goods, until the right shade is produced, or, if it is desired to exhaust the bath and so waste no color, until near the boiling point. The goods when taken out of the dye-bath must be washed very thoroughly, to remove the last trace of acid, which otherwise on drying would ruin the wool. It must be remembered that these Acid dyes hardly affect cotton in the least, and so the goods dyed in this way must be free from vegetable fibres, if level dyeings are to be obtained. In dyeing wool skeins commercially it is, of course, of the utmost importance to have the colors perfectly level and uniform. This uniformity is obtained easily enough, when using these Acid dyes, by having the wool thoroughly wet before placing it in the dye-bath; by having it well loosened out and well stirred so that the color will penetrate evenly every part of the material; and, finally, by starting the bath at a moderate temperature, and heating it gradually, until the proper shade is obtained. For handicraft dyeing the student is strongly advised to practise shaded and irregular effects, the so-called Rainbow dyeing, with wool in skeins, just as, in previous lessons, with raffia and with cotton. By using coarse heavy yarns, very beautiful two and three color effects can be produced, which, when used for embroidery or weaving, will prove most interesting.