Chemistry in ancient times

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Engraving by Pieter Brueghel the Elder : The Alchemist

The chemistry in ancient times existed in the form of practical fire assaying (as applied knowledge on chemical skills and techniques) with its capacity as natural philosophical thought and theory building with increasingly alchemical imprint ( "secret knowledge" Alchemy ) on the other. Theory and practice were only combined at the beginning of modern times, when both were placed on the basis of scientific work.

Ancient skills and tasting skills

Campfire

Nobody can say when primitive men began to worry about the substances, their properties and transformations, which we call chemical reactions . "The earliest evidence of the controlled use of fire comes from Koobi Fora in East Turkana 1.5 million years ago."

In antiquity , many chemical processes were known to the higher cultures - most of the processes and reactions were carried out with the help of fire and very soon after their discovery became part of the respective cultures:

Stone age

In the Stone Age (before 2000 BC) were discovered:

  • The generation of friction fire (for heating and lighting)
  • The pottery (clay distillery)
  • Cooking, drying and preserving food by boiling / thickening
  • The extraction of fat , sebum and oil from food (e.g. for operating oil lamps).
  • Furthermore, the metals gold , silver and copper were known because they could be found in nature, as was iron (from iron meteorites ), which, however, could not yet be processed.

Bronze age

In the Bronze Age (around 1900 BC - 650 BC) the following were discovered with the help of fire :

  • The production of bronze (copper and tin ores .) Incl Kupfererzröstung ( oxidation of sulphide ores, for example: CuS + 2 3 O 2 → 2 CuO + 2 SO 2 )
  • Charcoal making ( charcoal production ; charcoal as fuel and reducing agent for copper and bronze production, for example from copper carbonate (CuCO 3 ), but also CuO, CuS and SnS 2  ; it was also discovered here that bellows help to increase the heat of the fire) ,
  • The lime burning (CaCO 3 → CaO + CO 2 ; slaking: CaO + H 2 O → Ca (OH) 2 , the slaked lime then hardens under the influence of carbon dioxide from the air to the product calcium carbonate).
Iron ore ( ribbon ore )

Iron age

The Iron Age (from around 1000 BC) began with the discovery that iron ores can also be reduced to metal in a charcoal fire with bellows (malleable carbon-containing iron). The discovery of the much harder iron brought great military advantages to the corresponding cultures (Egyptians, Philistines, Mesopotamians, later Persians, Greeks and Romans). Various peoples also discovered:

Practical skills and knowledge of ancient chemistry

The following were known of the chemical processes taking place in the cold until the Iron Age:

So ancient researchers learned chem with the help of the processes and products listed above. Processes such as roasting, melting, boiling, straining, filtering, clarifying, drying, distilling, crystallizing and cementing - the latter, for example, to separate silver and gold - as well as the production of false gold (copper was coated with a gold amalgam and the mercury 4- evaporated up to 5 times or cinnabar varnish was applied to sheet silver) or “gold stretching” (adding base metals to the gold).

Ancient theories about matter and the transformation of matter

Greek natural philosophy

Greek natural philosophers such as Anaxagoras (around 500 BC - 428 BC) and Socrates (470–399 BC) also thought about matter and the processes of material transformation in the cosmos and thus created the first theories. Aristotle (384 BC - 322 BC) claimed that there are only material foundations of things - something neither emerges from nothing, nor does something disappear and disappear into nothingness (materiality of the world). Thus, the search was made for the “primordial substance” from which all substances arise through transformation processes (according to Anaximenes, around 611 BC - 545 BC, through compression and dilution) - as the primary substances were considered: water (in the opinion of Thales v. Miletus, around 600 BC), air (after Anaximes, 585 BC - 525 BC) and fire (after Heraclitus , around 520 BC - around 460 BC, and Hippasus of Metapontium , around 500 BC). According to Empedocles (around 495 BC - 435 BC) there were "four eternal elements " - fire, water, air and earth - from which all matter is created.

According to Xenophanes (end of the 6th century BC), the "phlogiston" fuel consisted of particles of fire that floated in the air. According to Leucippus (500 BC - 440 BC) and Democritus (460 BC - 370 BC) all four elements (fire, earth, water, air) consisted of the smallest, indivisible "splinters" or particles (Greek: “atomos”, indivisible) of different sizes and shapes that combine to form other substances.

In contrast to Aristotle (384 BC - 322 BC; "There are only material foundations of things" - materiality of the world), Plato (s) (427 BC - 347 BC ) thought In the cosmos there is the “spirit” as a non-material, formative force above matter, immortal and essential. Plato took over Democritus " atomistics ". For him the atoms were tetrahedral (in the element fire), cubic (earth), octahedral (air) and icosahedral (water). Aristotle speculated: "As a result of the action of the form, the substance changes or gains its shape - like the stone through the work of a sculptor." He assumed that the very first form-giver and mover was God . A substance like rust or roasted iron ore (ferric oxide), which could be melted into iron in a fire, but rusted again in air and water, was for Aristotle a “mixture” of fire, earth, air and Water particles , a continuum in which the smallest particles have given up (lost) their old properties (whereas today we know that iron and oxygen atoms are bound in iron oxide with unchanged properties and in certain, discontinuous numerical ratios). Aristotle described an element as an inseparable primordial material , which is based on all opposites:

  • Earth - cold and dry
  • Fire - warm and dry
  • Air - warm and humid
  • Water - cold and damp.

For him, metals were, for example, mixtures of the element earth (cold, dry) with a higher proportion of water (damp and cold) than the mixed substance “stone”. In rock, on the other hand, the atoms were firmly connected, while for him air was a substance in which there had to be a lot of empty space between the mobile air atoms (because, as Democritus had already established: an arrow can easily penetrate air, but collides with rock from).

Ancient Chinese natural philosophers and alchemists

In addition to the speculations of Greek natural philosophers about “kosmos” (the world order), “to apeiron” (the in-definite, infinite), “atomos” (the indivisible) and “theos” (God, the divine) were the Arab alchemists in the Middle Ages Source of insights from European “gold makers”, researchers and scholars. The Arabs, however, had much of their alchemical knowledge from the Chinese, who had thought about the " Dao " (the right way, the world or natural order) and " Xian " (the immortals).

Sulfur in gypsum from the Weenzen gypsum pit

Already in antiquity, with Wei Boyang (2nd century) and Ge Hong (283–343), there was - out of the endeavor to bring oneself into harmony with the eternal Dao - the endeavor to produce vermilion immortality elixirs through the union of the male Principle of Yang (in relation to sulfur) and the feminine principle of Yin (mercury): from the beginning, “metal” was considered an “element”.

It is said of Wei Boyang that he made a life elixir with three students and tested it on a dog. This immediately fell dead. Wei Boyang turned to his students questioningly. They asked: “Master, would you dare to take the elixir yourself?” He replied: “I left the ways of the world, family and friends, to go to the mountains; I would be ashamed to return without having found the Tao of Immortality. Dying on the elixir would be no worse than living without the Tao. I have to take it. ”And he ingested it and died, as did one of his students. But the other two left the mountains to buy coffins. After they had left, the master, his disciple and their dog woke up again and retreated further into the mountains to walk the path of the immortal. When his two students heard about this from a woodcutter, they were deeply ashamed.

Similarly , Ge Hong, who was converted to Daoism , searches for the Xian-Shank (immortality) in which the rational Confucians do not believe. The Arabs, and after them the European alchemists, believed Ge Hong, because he argued chemically and religiously: If the doves have no organ for thunder and the blind for the sun, the sun and thunder still exist. So should immortality and gold making be impossible simply because no one has succeeded in them yet? The ignorant will not believe that red lead (Pb 3 O 4 ) and white lead (PbCO 3 ) are both transformation products of lead or that you can make glass out of ashes !

He believed that the elixir only works if you have a certain foundation of good works and a strong belief . But then the xian shaft works in gold and cinnabar, and its elixirs therefore contain things like mercury, arsenic, copper, lead, vinegar , wine and honey and could cause insensitivity to heat and cold, shadowlessness , invisibility, levitation , telepathy , omniscience , Longevity for several centuries up to immortality . For learning alchemy, however, he recommends: “The choice of the right teacher is more important than hard study!”, He is more important than his own parents, and only the right teacher helps the student to escape death. Recipe example for artificial gold (according to Ge Hong): Ingredients: cinnabar, mercury, realgar, ox bile, salt, copper sulfate and charcoal. Procedure: Several weeks of laboratory work to reduce the Cu and As compounds using charcoal and salt as flux, result: A copper-arsenic alloy with a gold-like appearance. Further “false gold” products: “ Musivgold ” (SnS 2 ), mercury oxide, “pai chhien” (white lead, a Cu-Zn-Ni alloy), product discovered by the way: “huo yao” (the “fire drug”, a Kind of gunpowder).

The ancient knowledge and beliefs of ancient Chinese alchemists later found their way through the Islamic world into medieval Europe.

See also

literature

  • Wilhelm Strube: "The historical path of chemistry", Volume I, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig 1984 in 4th edition, ISBN ./., VLN 152-915 / 81/84
  • Ernst F.Schwenk: “Great moments in chemistry. From Johann Rudolph Glauber to Justus von Liebig ”, Verlag CH Beck, Munich 1998, ISBN 3-406-42052-4
  • Heinz Haber: "The substance of creation", Rowohlt Taschenbuch Verlag, Reinbek near Hamburg 1968, ISBN 3-499-16625-9
  • Edmund O. von Lippmann : Chemical and Alchemical from Aristotle. In: Archive for the History of Natural Sciences 2/3, 1910/1912, pp. 234–300.
  • Friedemann Rex : The oldest molecular theory. On Plato's quasi-chemical thought game in Timaeus (around 360 BC) , in: Chemistry in our time , Volume 23, 19879, pp. 200–206; doi: 10.1002 / ciuz.19890230604
  • F. Rex: Chemistry and Alchemy in China . In: Chemistry in Our Time . Volume 21, 1987, pp. 1–8, ISSN  0009-2851
  • Lucien F. Trueb: The chemical elements. A journey through the periodic table . S. Hirzel Verlag, Stuttgart 2005, ISBN 3-7776-1356-8
  • Michael Wächter: Brief history (s) of the discovery of chemistry in the context of contemporary history and natural sciences , Verlag Königshausen und Neumann, Würzburg 2018, ISBN 978-3-8260-6510-1
  • Klaus Volke: "Chemistry in antiquity - with special consideration of Mesopotamia and the Mediterranean countries", media center of the TU Bergakademie Freiberg, 2009, distribution: Akademische Buchhandlung, Freiberg, ISBN 978-3-86012-376-8

Individual evidence

  1. ↑ Friedemann Schrenk : The early days of man. The way to Homo sapiens. CH Beck, Munich, 1997, p. 100.