2011 years of the international chemical
Giorgio Nebbia nebbia@quipo.it
"Critics argue that the mining and metallurgical damage the trees and fields, which also you get food and timber, and destroy the birds provide meat quality and cheer the soul with their singing. "This phrase, which appears from one of many ongoing debates on the effects of industry on the environment, but was written almost half a millennium ago by Georg Bauer, known as Agricola, which is celebrating the anniversary of the birth cinquecentesino.
Agricola politely reply to the criticism by saying that the negative environmental effects are certainly there, but that the mining activities offer endless materials useful to humans, gold and silver alum, sulfur, metals essential for the progress of iron, copper, zinc, mercury, antimony, and so on. The debate è contenuto nella principale opera di Agricola, il trattato in dodici libri "De re metallica", cioè sull'arte e la tecnica dell'estrazione dei minerali e della produzione dei metalli.
Agricola fu uno straordinario personaggio, figlio di un'epoca di transizione, all'alba della primissima rivoluzioine industriale, di quella che Lewis Mumford ha chiamato l'"era paleotecnica".
Agricola era nato nel 1494 a Glauchau in Sassonia (Germania) e aveva seguito, come si usava in quel tempo, studi classici e letterari nelle Università di Lipsia, Bologna, e Padova, per laurearsi poi in medicina nell'Università di Ferrara. Dal 1527 al 1533 ricoprì l'ufficio di medico a Joachimsthal (oggi Jachymov), in Bohemia (now Czech Republic) and, from 1534 until his death in 1555, was a doctor and then mayor of Chemnitz, in neighboring Saxony (Germany).
Although he wrote several works on medicine, on weights and measures, history and theology --- defended the Catholic faith from the attacks of the Protestant Reformation --- his main book is the great treatise on mining, first noted, appeared after his death in 1556. Living in Europe's biggest mining region of the time, in the heart of the Ore Mountains (Erzgebirge), was able to observe, study and report on all phases of mining and metallurgical industries.
"De re metallica" is beautiful work and was a huge success and was translated from Latin into many languages, including Italian, already in 1563, and has preserved over the centuries its freshness and charm enough to deserve, in 1912, a translation in modern English by the spouses and Louise Herbert Hoover, both mining engineers. Herbert Hoover later became president of the United States from 1929 to 1932: it was the president of the Great Depression, and was the predecessor of Franklin Delano Roosevelt, elected president in 1933. Hoover administration was responsible for the construction of one of the largest dams in the world, on the Colorado River, which bears his name. I do not think it's a case that the work of Agricola, typical of a period of revolution and industrial innovation, as were the early decades of the 1500s, has attracted a man like Hoover, who lived, in turn, the other major phase of modern industrial-technological revolution of the early 1900s.
Agricola describes not only facts and techniques and equipment, with meticulous precision and with a series of illustrations are very beautiful and interesting even today, a strong humanistic culture he compares the knowledge of his time with those of Greek and Latin classics. Agricola cites a large number of minerals, many shown for the first time, and explains the processes of transformation of minerals into metals, some of which still apply today.
The work on the art mining begins by explaining the rationale for studying the geology, mineralogy and metallurgy, and the qualities that an entrepreneur must have to do its job well. Meanwhile requires good observation skills to recognize the world around the veins of useful minerals, trade, mines and furnaces must be located near a forest and a river, the forest provides wood for the construction of wells and use as a source power for the furnaces and the water has carried away the debris of the crushing of minerals, even if the farm does not fail to detect damage resulting pollution.
Mining activity must be monitored by special officials who should receive a good education and culture geological and mining. Officials must be able to perform analysis on the mineral and agricultural cites the various methods used. The concentration of mercury in distilled and mineral is measured by weighing the mercury recovered, the gold concentration is measured by mixing the gold with lead impurity in a special pot called gold leaf lead and other metals are oxidized and are absorbed by land of the melting pot: still a little button of pure gold which is then weighed. The process of cups is still used today.
The transformation of minerals into metals requires furnaces where the ore is added with land fluxes and charcoal: search and retrieve the metal molten. Some of the drawings illustrate well the principle of operation and in some cases followed, with minor variations, even today. Agricola explains well that certain minerals, before being processed in the ovens, must be "roasted", that is heated to transform, for example, sulfides in metal oxides, an operation that generates harmful fumes and irritating. Metallurgical activities must therefore be carried out away from the city.
Some metals should be treated with concentrated acids and Agricola describes the process of manufacture of nitric acid by reaction of potassium nitrate with sulfuric acid. Moreover, the nitric acid is still important because it "dissolves" all metals except gold. The ninth and tenth, of the twelve books of which 'made the work "De re metallica", are dedicated to their precious metals: gold and silver.
The twelfth and final book explains the processes of the nascent chemical industry: it is described the preparation of the salt by evaporating in the sun or by the distillation of sea water, saltpetre, alum, sulfuric acid, sulfur and Glass, whose farm also illustrates the processes of swelling that had probably seen at Murano, near Venice
, during his stay in Italy.
A reading with the current knowledge, the work of Agricola Agricola shows that some substances confused and had no clear ideas on the actual composition of some minerals. With his work, however, we move from vision to
alchemical materials chemistry and engineering modern vision.
Agricola mentions for the first time, and with some skepticism, the use of the fork by dowsers to search for water and special metals.
Agricola soon, as we mentioned at the beginning, attention to pollution due to mining activities: the drawings illustrating his works clearly show the kilns where the smoke out you can imagine and corrosive acids. Agricola speaks with expertise in medicine, the harsh conditions under which the work is performed and the miners' diseases and intoxications in which they are exposed. Unlike Greeks and Romans, who used slave labor in the mines, at the time of Agricola's work in the mines is done by free men, workers and as entrepreneurs, whose health is endangered by the stench and fumes, but also by spirits elfs (radon emanation?) to the miners who make mischief and cause strange visions.
is to smile to think that a child of the Renaissance, a man so close to us, could have believed in these naive, but then there is not so to smile when you think that some "intellectuals" of our time believe even the esoteric practices and to spiritualism, perhaps things would smile if he could see us Agricola. A text
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