Page:History of the Royal Society.djvu/317

 with particles, as it were of Glass, the tinging of them yields more brightness, than the tinging of a Scabrous matter (such as unallumed Cloth is) can do. Analogous hereunto I take the use of Bran, and Bran-liquors in Dying to be; for Bran yielding a most fine Flour (as we see in the making of white Starch;) I conceive that this Flour entring into the pores of the Stuff, levigates their Superficies, and so makes the Colour laid on it, the more beautiful, just as we see, that all woods, which are to be gilded, are first smoothned over with white Colours, before the Gold be laid on.

'And indeed all other Woods are filled, not only as to their greater holes and Asperities, with Putty; but also their smaller Scabrities are cured by priming Colours, before the ultimate Colour intended be laid thereon.

'The next Mineral Salt is Salt-peter, not used by ancient Dyers, and but by few of the modern. And that not till the wonderful use of Aqua-fortis (whereof Salt-peter is an ingredient) was observed in the Bow-scarlet: Nor is it used now, but to brighten Colours by back-boyling them; for which use Argol is more commonly used. Lime is much used in the working of Blue-fats, being of Lime-stone calcined, and called Calke, of which more hereafter.

'Of the Animal Family are used about Dying, Cochineel (if the same be any part of an Animal) Urine of labouring Men, kept till it be stale and stinking; Honey, Yolks of Eggs, and Ox-gall. The three latter so rarely, and as the conceits of particular Workmen; and for collateral uses (as to increase weight, promote fermentation, and to scour, &c.) that I shall say very little more of them Rh