All your Tubs being thus rightly ordered, put in upon every Tubs bottom another (false) wooden bottom, perforated with many Holes, and let it lie two Fingers breadth distant from the true bottom: Upon this (false) bottom lay yet another made of Bull-rushes, or your small sort of Reeds which grow plentifully in Ditches about the thickness of a quarter of an Ell: In want of these Reeds throw in upon the aforementioned perforated bottom, the quantity of a Span (thick) of Chopt Hay, or Straw, laying some very thin boards thereon, that so it may not be scattered (or float) abroad. And your Vessels are made compleatly ready.
Now then, put of the Earth you have already tried and gathered, as much into each of your Tubs, as they can hold, yet with this Caution, That the top part of your Vessel be empty a Spans heighth. And observe this, that if you can get some old ashes of the Curriers, or Soap-boilers, as much of it as two or three Wheel-barrows will carry, it must be put in upon the topmost (made) bottom of the Tub, afore the Earth, but now spoken of, be put in. At the top of the earth, lay a Cover made of Twigs, (or Withes) and fasten it with a wooden stick at the top of the earth. This done, pour common water upon the earth contained in the Vessel, an Hands breadth in heighth, so as that it may rather touch (or be poured) on the Twigs, than the Earth it self, least the said earth become unequal thereby, and hollowed in several places. Let it stand thus for eight hours, which time being overpast, draw your Plug out, and let the water you poured on, run out at the hole beneath, which as long as it is muddy, you must always pour in again into the Vessel, repeating this so often, till it comes out clear, then keep it, and this water is called a weak Lee or Lixivium.
This done, pour common water again upon the earth from which the Lee hath been already, once separated, that so it may extract the residue of the Lixivium out of the earth; and this Lee is of no use, save that it may be poured on upon new earth, instead of simple water; for it oftentimes doth even yet contain a great deal of Nitre, insomuch, that you may sometimes extract out of an hundred weight thereof, three or four pound of Nitre.
This Extraction being finished, take out the unprofitable earth out of the Vessel, and put in new; and continue the Operation, after the aforesaid manner, reiterating it so long, and so often, until you have gotten store enough of the Lixivium, that the work of boiling be not intermitted for want of Lixivium.
Besides, there must be some Wooden Vessel placed at the upper part of the Copper which this Lixivium is boiled in, out of which may run so much Lixivium into the Copper as is wasted away by boiling, that so there may be still kept the same order of boiling, and the same quantity of Lixivium in the Copper. This boiling is to be on this wise continued, until a Centenary, or hundred weight of Lixivium in the Copper, yields according to the less assay (or weight) twenty five pounds of Nitre; and this may be done in two Days, and one Night.
This being thus done, you must have ready yet two Tubs, or Vessels (more) of Wood, made after the afore prescribed manner, and furnished with a (false) perforated wooden bottom, besides its own bottom, and likewise with such a bottom as is made of Reeds (or Bull rushes); only you are to observe this here; That there must be put yet another perforated wooden bottom upon this topmost bottom of Reeds, upon which there must be first cast in some chop’d Straw, then some Ashes of Firr, Beach, or any other Tree, so much in quantity as may overtop the Straw an Ell or Cubit, [Ulna] high; or rather (if it may be had for a very mean price) as much as may fill the Tubs, or Vessels. But yet, these Ashes are not to be just simply thrown in (as they are) upon the Straw, but afore this is done, they must be first well mixt together, then moistened with some of the best hot Lixivium, that there may be made a Mass. Then when the Ashes are on this wise prepared, and put in the Vessel, the Lixivium boil’d to its heighth, and which yields in the proof twenty five pound, must be poured thereon, as hot as possibly it may, and is to be often drawn off by the lower hole, until (if troubled or muddy) it becomes clear.
After that all the Lee hath thus passed through the Ashes of both Tubs (the which is done upon this account, That all its fatness may pass into (or be left with) the Ashes, which Ashes are hereby rendred stronger to wash withal) keep it in a peculiar Vessel.
Then pour the common Lee or Lixivium upon the Ashes remaining in the Tubs, which when it hath passed through the Ashes, is called the second stronger Lixivium: Then again pour on yet a third time, hot Lixivium, and when ’tis drawn off, it is called the second weaker Lixivium: Lastly, the common Lee, or Lixivium, may be poured on cold upon the Ashes, that so all the virtue of the same may be wholly extracted.
The Figure before going (Numb. 1.) will shew you the way of placing the Tubs, of preparing the Lixivium, and ordering the boiling.
A Are the eight Wooden Tubs, wherein the earth is put.