Page:History of the Royal Society.djvu/315

 2. 'Whether it be used to scour the Sordes, which may interpose between the Coloranda, and the Dying Stuff; and so hinder the due adhesion of the one unto the other: The boyling of several things first in Allum seeming to tend this way. But I find this work to be done in Cloth, and Rugs, by a due scouring of the same in the Fulling-mills with Earth, and in Silk with Soaps, by which they boyl out the Gums and other Sordes, hindring or vitiating the intended Colours.

3. 'Whether Allum doth intenerate the Hairs of Wool, and Hair-stuff, as Grograins, &c. Whereby they may the better receive and imbibe their Colours? Unto which opinion I was led by the Dyers; saying, that after their Stuffs were well boyled in Allum, that they then cleared them of the Allum again: But we find the most open bodied Cottons and Silks, to have Allum used upon them; as well as the harder Hairs. Nor is Allum used in many Colours, viz. in no Woad or Indico Blues; and yet the Stuffs dyed Blue, are without any previous inteneration quickly tinged; and that with a slight and short immersion thereof into the Blue-fat.

4. 'Whether it contribute to the Colour it self, as Copperas doth to Galls, in order to make a Black; or as Juice of Lemons doth to Cocheneel in the Incarnadives; or as Aqua-fortis impregnated with Pewter, doth in the Bow-Scarlet, changing it from a red Rose-Crimson to Flame-Colour. This use is certainly not to be denied to Allum in some cases; but we see in other cases, that the same Colours may be dyed without Allum, as well as with it, though neither so bright and lively, nor so lasting.

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