Besides this too, you may have a most certain sign of such Petry places by those Spiders that have a small body and round, and long feet, for they stick to those stones in abundant measure: For such Spiders do not feed upon hearbs, grass, flies or other insects, but on old Walls, and they seat themselves chiefest of all on those aforesaid stones. They are not all venemous as the common house Spiders are, and therefore the Children do gather them, and are much delighted with them. Now they sticking on to the softer sandish stones do most certainly demonstrate that Salt-petre is contained in them; for tis that which they are nourished with, and conserve their life by, and this I was willing to signify unto you. But put case that no such nitrous stones were to be found, yet however there is not the opportunity denied us of making Salt-petre of the common Lime-making stones, and of them there is every where plenty enough, if they are calcined by the benefit of Wood, and made nitrous with the juice of wood.
What shall I say of the Calcined fæces of Tartar which are yearly gathered up and thrown away in vast quantities, in all that tract which lies on the River Mhene, between Bamberg and Franckfort, whereas notwithstanding some hundreds of hundreds weight of Salt-petre might be extracted thence-from, did they but mind it. For whatsoever Tartar is therein contained, is all of it Salt-petre when ’tis duly boiled with a Lixivium of Lime, and being hence strained, and a sufficient evaporation made, it be set by to Chrystallize. For it attracts the soul after a magnetick manner, which Operation if rightly instituted, there may be prepared thence from a most inflammable nitre in three days space, the which is likewise of far greater profit than the getting out the Tartar by the help of a Press, and with a great deal of labour; or else than the making Potashes, as we see usually done.
Besides too, there are found other stones that being burnt do yield abundance of Salt-petre, such as are the Tophi (or soft sandy stones) which may be abundantly gathered near Triefelstein, which is a Monastery situate on the Mhene, in other places of Germany they make even whole Mountains: So that it is evident that there is no where any want of convenient matter to gather Salt-petre from, if Men would but set their hands to the work. These stones are obvious unto all; and who knows what Treasures the Woods (which we do not at all search into) abound withal? Would time permit me I could shew that various kinds of Metals are conserved in the Mountains situate between Kitzing and Franckfort, and especially in the Speshardensine (Mountain,) the disclosing of which, some other more commodious place will admit of.
Now follows what we mentioned of the aforesaid
LAZARUS ERCKER.
Of the manner of Boiling Salt-petre.
AND FIRST
By what means a Lixivium is to be made out of a Nitrous Earth.
If you are minded to make a Lixivium of such an Earth, dig it as deep as you shall find by proving it to be either good or naught, especially if you intend to make it in great quantity, and keep it in a dry place. Then take care to have some great wooden Tubs, or Vessels made, so large, that each of them may hold about some ten Wheel-barrows full of the Earth, and whereby you may be able to prepare Lixivium enough, answerable to the work you have proposed to your self to do, and to the bigness of your Copper. Now there are commonly required for such a work, to one Copper Pan that weighs two hundred weight, eight Wooden Vessels which are to be placed in such order, that on each side there may stand four in a row, opposite to each other. These same Tubs are to be so far distant from the next Collateral Vessels, as is requisite for the Wheel-Barrow wherein the Earth is brought to come between: Yea, and it is necessary that there be half an Ell’s space betwixt the said Tubs and the Earth, or Ground, it self, whereon they are placed. Likewise, each of the Vessels, or Tubs, must have a hole in the fore-part, and towards the bottom thereof, fit to put in a Plug (or Tap) at: Then finally, there must be put under those Plugs, a long Vessel like a Channel-pipe, which may receive in it the Lixivium running out of the Tubs, and may guide it along into a peculiar Wooden Vessel, as into a common Store-house set in the Earth hollowed for that purpose, to receive the said Lee in.