Gold During the Transition to Modern Scientific Views
"For I know by good and long experience and by many accurate trials that Quick-silver the most friendly mineral to the royal metals, can by no means or Artifice whatsoever be fixed and coagulated into either of the Royal Metals."
The interval between the publication of Agricola's De re metallica (1556) and the great controversy in earth sciences, instigated by Werner and Hutton and lasting into the early years of the nineteenth century, marks a time span of nearly three centuries, during which many changes took place in politics, social structure, economics, and science in Europe and the newly discovered (i.e., by Europeans) lands of the New World (Americas), Africa, the Far East, Siberia, and Australasia. The period witnessed in turn the great events of the aftermath of the Reformation (1517-1560), the exploration and exploitation of the newly found lands (Americas, Siberia, Africa, Australia, etc.), the continued expansion of capitalism and mercantilism, the rise and later decline of monarchial absolutism in Europe, the emergence of parliamentary monarchy in England, the Seven Years War (which removed French dominion from America 1759), the American Revolution (1775-1783), the French Revolution (1789-1795), and the rise and fall of Napoleon Bonaparte (1815). Amid all the vicissitudes of the period 1556-1820, there was steady progress in science. By the closing years of the period a large body of verifiable knowledge had accumulated in the fields of mathematics, astronomy, physics, chemistry, and medicine. In physics and astronomy the revolution begun by Copernicus (1473-1543) in his De revolutionibus orbium coelestium culminated in Newtons (1642-1727) monumental Principia, in which the geocentric Ptolemaic views of the solar system were abolished forever. Similarly in chemistry the pioneer work of Boyle (1627-1691) in demolishing the Aristotelian four element theory and establishing the clear definition of an element and compound and in challenging the current fanciful alchemical theories in his Sceptical Chymist led ultimately to the modern view of oxidation-reduction reactions, enunciated first by Lavoisier (1743-1794); these efforts finally overthrew the phlogiston theory that had sidetracked chemistry for almost a century. Technology also advanced greatly during the seventeenth and eighteenth centuries, particularly in mining methods, ventilation, and drainage as the demand for metals, especially the precious metals, grew. Most of this progress in mining technology took place in central Europe (Erzgebirge) and in England, and from these regions, many of the ideas of the period about ore-forming processes would soon originate.
Prospecting and discovery of gold deposits, remained largely a matter of chance during the transition period, although references in the literature of the period point to a greater appreciation of the role of indicators of auriferous deposits, such as quartz, gossans, mineralized springs, red earths, and depression lineaments along mineralized faults and fractures. Mining methods were improved over those utilized in the Late Middle Ages and Renaissance, including particularly the employment of horsepower on a wider scale during the seventeenth and early part of the eighteenth centuries and the introduction of the steam engine for pumping water from deep mines and other tasks during the last half of the eighteenth century and the early part of the nineteenth. Gunpowder (black powder) was used more extensively for blasting toward the end of the period, and there was much improvement in drilling, using handsteel methods for driving drifts and extracting the ore. Improvements in mine ventilation, drainage, timbering and lighting and in many of the metallurgical techniques led into those of the modern era. During the seventeenth century the study of ore deposits suffered a period of abeyance. In England Francis Bacon (1561-1626), onetime Lord Chancellor under James 1, was the foremost philosopher of the time and undoubtedly one of the greatest prophets of science. He sought to reform all knowledge and thus create a new learning, and he was a firm advocate of experimental method and inductive reasoning. Yet, in all of his many works, there is little of interest for the geologist, except perhaps his speculations on continental drift, and nothing specifically about mineral deposits. Rather one has to turn to an agriculturist, Gabriel Plattes, and to a South American curate, Alvaro Alonzo Barba, to discover the state of the theories of the origin of ore deposits.
In Plattes A Discovery of Subterraneall Treasure (1639, p. 34)), we read in the first part of chapter 8 dealing with gold the following interesting discourse:
And later in the chapter (p. 36) we learn Plattes' views on the epigenetic origin of gold from subterranean vapors:
"Now whereas I have formerly affirmed that all mettals in general are generated of the clammy and gluttenous part of the subterranean vapours, arising from Bituminous and Sulphurous substances, kindled in the bowells of the earth: it behooveth me to shew how gold, such a fixed substance can be found pure of it selfe, and not mixed with other base mettals.
And the reason of this can be no other, but because that all other mettalls whatsoever will putrifie in the earth in length of time, and turne to earth againe; but gold wil never putrifie by reason of his excellent composition, being made of a Balsamick Sulphur or fatnes, which is incombustible, and differeth from the Sulphure or fatnes contained in the other mettals, even as naturall Balsome differeth from all other oyles, and fat substances: so that though it be an oyle in shew, yet it will sink in water, whereas all other oyles wil swimme upon the top of the water...
Now whereas the substance of gold is not subject to putrifie in the earth by any length of time, it is probable enough that other metalls might be generated with it at the first, and afterward putrified and consumed from it in length of time, leaving the gold pure...
And the reason why the hotter the Country is, the richer the Minerals are, can be no other but the same, that roasted meates are sweeter than boyled meates, or raw meates: the reason whereof is plaine, for that the rawish and unsavory part is exhaled by the heate of the fire, leaving the sweeter part behind.
Rafal Swiecki, geological engineer email contact
This document is in the public domain.