THE FIRST PART

Coarse and fine sand containing flaming and light gold gives a blue smoke in cremation and is exalted in color, namely to brown; but that which does not change contains nothing.

Fine yellow or red earth passing like a vein through sand or a mountain also contains gold, which is for the most part volatile and immature, flying off in reduction, having an entry into Luna silver and other metals, and thus is conservable in this way.

For the sake of better knowledge, you can also test the stones with white fusible glass, a matter about which I have written in the Fourth Part of the Philosophical furnaces, so that you may not have cause to impute the blame of an error committed to me; wherefore I would have you forewarned that not all stones contain gold, nor is it separable from all by the spirit of salt: Therefore, they must be known before they are applied to the work.

First, it is necessary to extinguish the flints, made white-hot in the fire, in cold water, and afterwards, when removed and cooled, to crush them most finely.

NB. When they are crushed in a mortar, the better parts can easily be separated from the ignoble ones; for while they are being crushed most finely, the better part always goes first into a red powder, leaving behind the ignoble, coarser, and harder part, containing little or nothing. Even if they are crushed coarsely and passed through a very fine sieve, the finer part passes through the sieve like red powder, leaving the useless part in the sieve like a white powder, which is to be thrown away. Even if some redness still appears in them, it is necessary that they be crushed again in a mortar, and again the better part will go into a red powder, leaving the ignoble, coarser, white part in the sieve, and therefore to be thrown away. It must be observed, however, that not all and every flint is so separable by the benefit of crushing; for some, when crushed, retain one and the same color everywhere, without any separation of the better parts; these must be crushed most finely in their entire substance and extracted. But those (namely the separable ones) are extracted more easily, because all the gold contained in one pound can generally be collected from three or four ounces crushed most finely and separated in the aforementioned manner; so that there is no need to extract the whole stone, nor to consume such a quantity of the spirit of salt. But sand and clay do not have need of such preparation, but are extracted by the pouring of the spirit of salt without previous preparation.