Point X.
Pewterers may harden their Tin or Pewter, and give to it an elegant whiteness, so that it will resemble Silver both in colour and sound; neither will it easily tarnish, and by reason of its hardness, will last longer than common Pewter.
If Tin be often melted, and extinguished in a lixivium of fixt Nitre, it is made harder than it was before; but if it be put to Nitre in Flux, and suffered to melt in it; then also it will be more hard. NB. But if the Tin be reduced into Scoria by Nitre, and the Scoria again reduced, it will be rendered harder and fairer, than by the two former ways.
Point XI, XII, XIII.
Cabinet-makers may strike an excellent Black upon Pear-tree, Cherry-tree, Box, Walnut-tree, and other hard Woods, which may be used for curious Works instead of Ebony. Skinners or Furriers may dye their Ermins, Fox-skins, Wolf-skins, and the like Furs, with a scarlet, crimson, or deep black colour, far exceeding the natural. In like manner Feather-dyers may swiftly give any lasting colour to their Plumes.
If an Aqua-fortis be destilled from Nitre and Vitriol, and a little silver dissolved in it, and Rain water poured thereon (for the weakening of the Aqua-fortis) then not only all hard Woods, are blacked by it, so that they represent Ebony, but also skins and feathers are made black as a coal, a ground being first laid upon the feathers, skins, or woods, that the Colours may remain and endure firm. Therefore the 11, 12, and 13 points are thus verified together.
Point XIV.
Taylors may take out Spots or Stains, out of Woolen, Linen, or silk Garments, and restore their Beauty.
Of fixed Nitre is made a Soap, so subtile and pure, that by it all Spots may be taken out of Garments.