TAKE of the purified Tartar before, one Pound; clear Filings of Iron or Steel two Ounces; pure rain Water eight Pints; boil all in a clear Iron Kettle, as long as you boil an Egg sit for eating, or somewhat longer; then pass it thro' a woollen Strainer, and stir the Liquor till it be cooled, and you shall have a Powder of a chalybeate Tartar, of a greenish Colour, and shining when dry, containing in it the Vitriol of Mars. This is incomparably more aperitive than the fore going Preparations, and has all the Virtues of them exalted to a high Degree, and therefore a most prevalent thing against the Green-Sickness, and other hysterick Diseases; but if you prepare it of the purified Tartar that is soluble, it will easily dissolve in any Liquor, and so be more sit for Use. Dose from half a Scruple to half a Dram. Note, That the Artist had best prepare the purified Tartar of which this is to be made, by itself, because most of what is sold in the Shops is adulterated with Alum or Nitre, or both. Or you may make it thus:
Take of Tartar crystalliz'd one Pound; Rust of Iron three Ounces; Water six Quarts; boil all together for half an Hour, or so long as to dissolve the Tartar; strain it hot thro' a Bag into an Iron Kettle, and in twelve Hours it will shoot into brown Crystals at the Sides and Bottom of the Kettle; decant the Liquor, evaporate it half, and set it to crystallize again in the former Kettle: Continue these Operations till you have all your Tartar, which dry in the Sun, and keep for Use. It is a good Remedy for Obstructions, especially against Quartan Agues, having all the Virtues of the purified Tartar, but much more powerful. Dose from fifteen Grains to two Scruples, in Broth or other proper Liquor.