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History of chemistry: historical background from prehistoric times

From philosophy, going through magic and mysticism to finally reach scientific thought, chemistry has become a fundamental part of the daily life of the human being. Thanks to the multiplicity of discoveries and studies that have been made throughout history, today it is possible to create various materials for the collective benefit. Detergents, cleaning products, fuel and other substances.

The history of chemistry has gone through various forms throughout time, starting from philosophical thought to the scientific field
Image by Angelo Rosa from Pixabay

Among other areas, this scientific branch has also been significant in terms of health issues, since advances in chemistry in medicine have allowed the development of compounds that function as medicines for humans. Besides, it is also closely linked with nutrition and with the study of the nutritional components of each food consumption product. 

Prehistory

The origin of chemistry could be considered in the use of fire, which originates with a chemical reaction. The Homo erectus  is the first hominid to control it began, some 400,000 years ago. However, new discoveries show that humans had the ability to control it about 1.7 million years ago, although there is a debate among scientists regarding these dates.

By Nathan McCord, US Marine Corps [Public domain], via Wikimedia Commons

On the other hand, the rock art of the first Homo sapiens  also supposes a little knowledge of chemistry; the paintings required the mixing of animal blood with other liquids.

Later, Homo sapiens began to produce bronze, around 3500 BC. Then, in the Iron Age, it began to be mined around 1200 BC by the Hittites.

Old age

Babylon

This time is marked from 1700 BC to 300 BC It was specifically during the government of King Hammurabi, when a first list was drawn up with the classification of the heavy metals known for the time in conjunction with the celestial bodies. 

Ancient Greece

Later, the interests regarding the nature of matter and substances began, within the thought of the philosophers of Ancient Greece. From 600 BC, characters such as Thales of Miletus, Empedocles and Anaximander, already thought that the world was made up of certain types of earth, air, water, fire and other unknown resources.

Thales of Miletus painting

From 400 BC, Leucippus and Democritus proposed the existence of the atom, affirming that this was the fundamental and indivisible particle of matter, thus refuting that matter could be an infinitely divisible entity. 

Democritus sculpture

Aristotle

However, Aristotle continued the theory of the elements and apart he added the perspective that air, water, earth and fire, resulted from the combination of certain conditions such as heat, cold, humid and dry.

Besides, Aristotle was also opposed to the indivisible particle version and believed that one element could be transformed into another depending on how its qualities were handled .

Middle Ages

Alchemy

Many of the conceptions of the transformation from one element to another influenced in the Middle Ages , especially within the field of alchemy. 

In times before ancient Greece, many tasks allowed the development of knowledge as a result of experimentation with materials. This is how some resources arise such as glass, bronze, silver, dyes, steel and more, which came from experiments thousands of years ago. 

Among those who had the most knowledge regarding the combination of materials, were jewelers and goldsmiths, who used to work with precious and semi-precious materials. They implemented various techniques developed through experimentation such as distillation, smelting, amalgamation, and more. 

This practical diversity, together with the thought of Aristotle, formed the foundations for the impulse of alchemy as a method of exploration and the search for new materials through chemistry. One of the best known objectives of this trade was to find a way to transform simple materials into more valuable metals such as gold. 

The myth of the “philosopher’s stone” is also born, known for being a magical object or substance which could convert any ordinary metal such as brass or iron into gold or silver. 

As for other interests, the alchemists also set out in search of the elixir of life, a substance capable of curing any disease and even bringing someone back from death. 

However, despite the absence of scientific evidence, alchemy allowed various breakthroughs and discoveries regarding components and substances. Elements such as mercury and a diversity of pure and strong acids were developed. 

Modernity

From the sixteenth century, new forms of research were opening the way to the differentiation between chemistry and alchemy, however, the relationship that existed between them cannot be refuted. 

Robert Boyle

Various characters in history such as Isaac Newton and Robert Boyle, were linked to the practices of alchemy, although they were integrating the systematic processes and quantitative methods that would incline them towards chemistry within the scientific area. 

It was precisely Boyle who wrote The Sceptical Chymist and defined that an element is a substance that cannot be divided into other simpler substances through chemical means. This was one of the works that discredited Aristotle’s theory, which had been one of the foundations of alchemy.

The Enlightenment brought with it the impulse of new methodologies for experimentation. This is how chemistry is promoted as the path linked to reason and experimentation with a view to progress, thus rejecting everything with a mystical tone such as alchemy. 

The Chemical Revolution

With the Enlightenment, various theories and new discoveries began to emerge from scientific searches. 

Phlogiston theory

It was developed and popularized by the German alchemist and chemist, Georg Ernest Stahl. It was one of the first attempts to explain the combustion process. This suggested the existence of “phlogiston”, a type of fire that possessed any combustible substance.

Coal combustion, which served as the basis for the phlogiston theory

Stahl claimed that a flammable substance lost weight after burning, due to a loss of phlogiston. One of its main references was coal.

However, this theory faced a great contradiction, since metals increase in weight after combustion, a fact that began to generate doubts and that later would fall into the discard of this theory.

Lavoisier works

Graphic portrait of Antoine Lavoisier (Source: H. Rousseau (graphic designer), E.Thomas (engraver) Augustin Challamel, Desire Lacroix [Public domain] Via Wikimedia Commons)

Antoine-Laurent Lavoisier was a nobleman and chemist of French origin who managed to fuse various findings that allowed him to come across oxygen as one of the main agents in the combustion or oxidation process, he ended up implementing for this fact.

Lavoisier is known as the father of modern chemistry for his multiple findings and studies that led him to the formulation of the theory of the “law of conservation of mass”. This law establishes that in any type of chemical reaction, the mass of the reacting substances is equal to the mass of the resulting product. In this way, the passage from alchemy to modern chemistry would be definitively marked.

Dalton’s atomic theory

John dalton

Already during the nineteenth century, John Dalton gave way to one of the most significant theories for the development of chemistry as a science, the “atomic theory”. In it, he states that each element has an indivisible particle called an atom, a term that he used from the ancient thought of Democritus and Leucippus. In addition, he proposed that the weight of the atoms can vary depending on the element in question. 

Among other of his most outstanding hypotheses, he highlights on the one hand that a chemical compound is a substance that always contains the same number of atoms in the same ratio.

On the other hand, Dalton stated that in a chemical reaction, the atoms of one or more components or elements are redistributed in relation to the other atoms to form a new compound. In other words, the atoms themselves do not change their identity, they only rearrange themselves.

Birth of physical or physicochemical chemistry

At the time of the 19th century, various advances in physics were also influencing the development of chemistry for the understanding of how substances reacted to certain factors within what would be known as thermodynamics. Thermodynamics is related to the study of heat, temperature, and other manifestations of energy that can influence substances and matter. 

By relating thermodynamics with chemistry, the concepts of entropy and energy began to be integrated within this science. Other advances also marked the momentum of physicochemistry such as the emergence of electrochemistry, the development of instruments such as the chemical spectroscope and the kinetic study of chemical reactions. 

In this way, at the end of the 19th century, physical chemistry was already established as a branch of chemistry and began to be part of the academic studies within the teaching of chemistry in various parts of the world, including North America. 

It is worth highlighting the contribution of Dimitri Ivanovich Mendeleev in 1869 and Julius Lothar Meyer in 1870, who carried out the classification of the elements, which in turn allowed the discovery of materials such as plastic, solvents and even advances for the development of medicines. . 

Dmitri Mendeleev contributions
Dimitri Ivanovich Mendeleev

The second “Chemical Revolution”

This stage is defined by relevant discoveries such as electrons, x-rays, and radioactivity. These events took place in just a decade, from 1895 to 1905, marking the entrance of the new century with important scientific discoveries for the contemporary world. 

In 1918 the British physicist Ernest Rutherford discovered the proton and this would promote further studies such as those of Albert Einstein and the theory of relativity. 

Young Ernest Rutherford. Source: Unknown, published in 1939 in Rutherford: being the life and letters of the Rt. Hon. Lord Rutherford, O. M [CC BY 4.0 (https://creativecommons.org/licenses/by/4.0)]

The 19th century also marked advances in biochemistry regarding substances that come from living things, such as plants , animals, and humans. Chemists like Emil Fischer made great contributions to this branch, managing, for example, to determine the structure and find the nature of various proteins, amino acids, peptides and carbohydrates. 

Discoveries such as “vitamins” in 1912, independently made by British biochemist Frederick Hopkins and Polish-born biochemist Casimir Funk, allowed significant progress within the field of human nutrition. 

The discovery of the structure of DNA was one of the most important discoveries of chemistry in the 20th century

Finally, the most revealing and important discovery for the relationship between chemistry and biology was that of the structure of deoxyribonucleic acid (DNA) by the American geneticist James Watson and the British biophysicist Francis Crick.

Development of instruments for progress for science

Among the most outstanding elements for the progress of chemistry in a variety of fields is the development of work and measurement instruments. Mechanisms such as spectrometers to study radiation and the electromagnetic spectrum, as well as the spectroscope, would allow the study of new reactions and substances related to chemistry.

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