A large number of extracts have been made from this part of the subject, because the book gives the position of positive, as distinguished from speculative, Alchemy at the time. It is the Editor's desire to show that at this period there was a system of theory based on the practical knowledge of the day.
Chemistry took its rise as a science about four hundred years before our era. In the fragments of two of the four books of Democritus we have probably the earliest treatise on chemical matters we are ever likely to get hold of. Whether it is the work of Democritus or of a much later writer is uncertain. But merely taking it as a representative work of the early stage of chemistry, we remark that the receipts are practicable, and some of them, little modified, are in use to-day in goldsmith's shops. The fragments remaining to us are on the manufacture of gold and silver, and one receipt for dyeing purple. In this state of the science the collection of facts is the chief point, and no purely chemical theory seems to have been formed. Tradition, confirmed by the latest researches, associates this stage with Egypt.
The second stage in the history of Chemistry—the birth of Alchemy in the Western World—occurred when the Egyptian practical receipts, the neo-Greek philosophies, and the Chinese dreams of an "elixir vitae" were fused into one by the Arab and Syriac writers. Its period of activity ranges from the seventh to the tenth centuries. Little is really known about it, or can be, until the Arabic texts, which are abundant in Europe, are translated and classified both from the scholar's and the chemist's standpoint. Many works were translated into Latin about the end of the tenth century, such as the spurious fourth book of the Meteorics of Aristotle, the treatises of the Turta Philosophorum, Artis Auriferae, etc., which formed the starting-point of European speculation. The theoretical chemistry of our author is derived from them.
The third stage of chemistry begins with the fourteenth and ends with the sixteenth century. It is characterized by an immense growth of theory, a fertile imagination, and untiring industry. It reached its height in England about 1440, and is represented by the reputed works of Lully (vixit circ. 1300), which first appeared about this date. In this period practical alchemy is on its trial.
The fourth stage begins with Boyle, and closes with the eighteenth century. Still under the dominion of theoretical alchemy, practical alchemy was rejected by it, and its interest was concentrated on the collection of facts. It led up to modern chemistry, which begins with Lavoisier, and the introduction of the balance in the study of chemical change.
Chemical theory, then, in our author's time stood somewhat thus. Metals as regarded their elemental composition were considered to partake of the nature of earth, water, and air, in various proportions. Fossils, or those things generated in the earth which were not metals, were again subdivided into two classes—those which liquefy on being heated, as sulphur, nitre, etc., and those which do not. The metals were considered to be composed of sulphur and mercury. These substances are themselves compounds, but they act as elements in the composition of metals. Sulphur represented their combustible aspect, and also that which gave them their solid form; while mercury was that to which their weight and powers of becoming fluid were due.
This theory was due to two main facts. Most ores of metals, especially of copper and lead, contain much sulphur, which can be either obtained pure from them, or be recognised by its smell when burning. This gave rise to the sulphur theory, while the presence of mercury was inferred doubtless from the resemblance of the more commonly molten metals, silver, tin, and lead, to quicksilver. The properties of each metal were then put down to the presence of these substances. The list of seven metals is that of the most ancient times—gold, electrum, silver, copper, tin, lead, iron; but it is clearly recognised that electrum is an alloy of gold and silver.
Most of the facts in this book are derived from Pliny through Isidore, but, that the theory is Arab in origin, one fact alone would convince us. A consideration of the composition of the metals shows us that tin is nearest in properties of all metals to the precious ones, but tin is precisely the metal chosen by Arab alchemists as a starting-point in the Chrysopoeia.
Beside their scientific interest these passages have supplied many analogies. When Troilus is piling up his lover's oaths to Cressida, his final words are:
"As iron to adamant, as earth to centre;"