Preface To The Second Book - Concerning The Semiminerals.

HAVING previously described the metals to you, before I proceed any farther I do not wish to fail to tell you, as I promised to do in the first chapter on metals, what I have learned through experience concerning the semiminerals, although this may seem to you outside our proposed subject. Since these are not produced by Nature as all rock or all metal they are called semiminerals by speculative physicians. Many kinds of these are found; those that resemble rocks are earthy, very difficult to liquefy, and much more adapted for adorning paintings than for anything else. Those that liquefy with fire, like sulphur, antimony, marcasite, [22] calamine, zaffre, manganese, and others, resemble the metals almost like brothers. Some others are more watery so that they dissolve in water, although they are fairly dense, and are obtained and reduced to their, perfection by means of water. These are the salts, vitriol, rock alum, and saltpeter. To these, as a watery thing, belongs also quicksilver, as it is commonly called because of its motion. Although it appears. not only liquid, but very liquid, this is not at all similar in its effects to any of the above. Indeed, it retains its same being until its very form is consumed. Since the reasons for its effects are almost impossible to investigate, I do not intend to speak of them here or to enter now this maze of speculation, because I wish to make definitely clear to you what this quicksilver really is. Therefore, leaving aside opinions and disputes, I shall take only those of the said semiminerals that I know are useful. First we shall see the method by which the semiminerals can be found and then how they are to be extracted from their matrices. These, perhaps, have no less need of effort and industry than the metals since they are substances completely hidden in the rocks or in the earth. For this reason some of these that are sought are made use of by means of fusion after they have been mined from their mother mountains, and some others need to be disposed by a certain maturative corruption, now with moisture and coldness, now with dryness and heat, as with waters, rains, frosts, or long baking in the sun, with fire, or even with a strong reheating within themselves. Most of them can finally be brought to the desired end by means of solution with water and fire.