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Early Metallurgy Main articles: History of ferrous metallurgy and History of metallurgy in the Indian subcontinent The earliest recorded metal employed by humans seems to be gold which can be found free or "native". Small amounts of natural gold have been found in Spanish caves used during the late Paleolithic period, c. 40,000 BC.[2] Silver, copper, tin and meteoric iron can also be found native, allowing a limited amount of metalworking in ancient cultures.[3] Egyptian weapons made from meteoric iron in about 3000 BC were highly prized as "Daggers from Heaven".[4] Arguably the first chemical reaction used in a controlled manner was fire. However, for millennia fire was seen simply as a mystical force that could transform one substance into another (burning wood, or boiling water) while producing heat and light. Fire affected many aspects of early societies. These ranged from the simplest facets of everyday life, such as cooking and habitat lighting, to more advanced technologies, such as pottery, bricks, and melting of metals to make tools. It was fire that led to the discovery of glass and the purification of metals which in turn gave way to the rise of metallurgy.[citation needed] During the early stages of metallurgy, methods of purification of metals were sought, and gold, known in ancient Egypt as early as 2900 BC, became a precious metal. Bronze Age Main article: Bronze Age Certain metals can be recovered from their ores by simply heating the rocks in a fire: notably tin, lead and (and at a higher temperature) copper, a process known as smelting. The first evidence of this extractive metallurgy dates from the 5th and 6th millennium BC, and was found in the archaeological sites of Majdanpek, Yarmovac and Plocnik, all three in Serbia. To date, the earliest copper smelting is found at the Belovode site,[5] these examples include a copper axe from 5500 BC belonging to the Vinča culture.[6] Other signs of early metals are found from the third millennium BC in places like Palmela (Portugal), Los Millares (Spain), and Stonehenge (United Kingdom). However, as often happens with the study of prehistoric times, the ultimate beginnings cannot be clearly defined and new discoveries are continuous and ongoing. Mining areas of the ancient Middle East. Boxes colors: arsenic is in brown, copper in red, tin in grey, iron in reddish brown, gold in yellow, silver in white and lead in black. Yellow area stands for arsenic bronze, while grey area stands for tin bronze. These first metals were single ones or as found. By combining copper and tin, a superior metal could be made, an alloy called bronze, a major technological shift which began the Bronze Age about 3500 BC. The Bronze Age was period in human cultural development when the most advanced metalworking (at least in systematic and widespread use) included techniques for smelting copper and tin from naturally-occurring outcroppings of copper ores, and then smelting those ores to cast bronze. These naturally-occurring ores typically included arsenic as a common impurity. Copper/tin ores are rare, as reflected in the fact that there were no tin bronzes in western Asia before 3000 BC. After the Bronze Age, the history of metallurgy was marked by armies seeking better weaponry. Countries in Eurasia prospered when they made the superior alloys, which, in turn, made better armor and better weapons.[citation needed] This often determined the outcomes of battles.[citation needed] Significant progress in metallurgy and alchemy was made in ancient India.[7] Iron Age Main article: Iron Age The extraction of iron from its ore into a workable metal is much more difficult than copper or tin. It appears to have been invented by the Hittites in about 1200 BC, beginning the Iron Age. The secret of extracting and working iron was a key factor in the success of the Philistines.[4][8] In other words, the Iron Age refers to the advent of ferrous metallurgy. Historical developments in ferrous metallurgy can be found in a wide variety of past cultures and civilizations. This includes the ancient and medieval kingdoms and empires of the Middle East and Near East, ancient Iran, ancient Egypt, ancient Nubia, and Anatolia (Turkey), Ancient Nok, Carthage, the Greeks and Romans of ancient Europe, medieval Europe, ancient and medieval China, ancient and medieval India, ancient and medieval Japan, amongst others. Many applications, practices, and devices associated or involved in metallurgy were established in ancient China, such as the innovation of the blast furnace, cast iron, hydraulic-powered trip hammers, and double acting piston bellows.[9][10] Classical antiquity and atomism Democritus, Greek philosopher of atomistic school. Philosophical attempts to rationalize why different substances have different properties (color, density, smell), exist in different states (gaseous, liquid, and solid), and react in a different manner when exposed to environments, for example to water or fire or temperature changes, led ancient philosophers to postulate the first theories on nature and chemistry. The history of such philosophical theories that relate to chemistry, can probably be traced back to every single ancient civilization. The common aspect in all these theories was the attempt to identify a small number of primary classical element that make up all the various substances in nature. Substances like air, water, and soil/earth, energy forms, such as fire and light, and more abstract concepts such as ideas, aether, and heaven, were common in ancient civilizations even in absence of any cross-fertilization; for example in Greek, Indian, Mayan, and ancient Chinese philosophies all considered air, water, earth and fire as primary elements.[citation needed] Ancient World Around 420 BC, Empedocles stated that all matter is made up of four elemental substances - earth, fire, air and water. The early theory of atomism can be traced back to ancient Greece and ancient India.[11] Greek atomism dates back to the Greek philosopher Democritus, who declared that matter is composed of indivisible and indestructible atoms around 380 BC. Leucippus also declared that atoms were the most indivisible part of matter. This coincided with a similar declaration by Indian philosopher Kanada in his Vaisheshika sutras around the same time period.[11] In much the same fashion he discussed the existence of gases. What Kanada declared by sutra, Democritus declared by philosophical musing. Both suffered from a lack of empirical data. Without scientific proof, the existence of atoms was easy to deny. Aristotle opposed the existence of atoms in 330 BC. Earlier, in 380 BC, a Greek text attributed to Polybus argues that the human body is composed of four humours. Around 300 BC, Epicurus postulated a universe of indestructible atoms in which man himself is responsible for achieving a balanced life. With the goal of explaining Epicurean philosophy to a Roman audience, the Roman poet and philosopher Lucretius[12] wrote De Rerum Natura (The Nature of Things)[13] in 50 BC. In the work, Lucretius presents the principles of atomism; the nature of the mind and soul; explanations of sensation and thought; the development of the world and its phenomena; and explains a variety of celestial and terrestrial phenomena. Much of the early development of purification methods is described by Pliny the Elder in his Naturalis Historia. He made attempts to explain those methods, as well as making acute observations of the state of many minerals. |
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