ORIGINS AND HISTORY OF CHEMISTRY
Chemistry is a branch of science that has been around for a long time. The invention of metallurgy, for example, changed societies, culture dramatically when the “Iron age” occurred. Some knowledge about the nature of materials around us could be found in the oldest civilizations. In ancient Babylonia at the time of the famous ruler Hammurabi, they were already able to recognise and classify certain metals. But, as it is true for all other sciences, it was the ancient Greek civilization, the Greek philosophers with their great effort to understand fýsis - the nature, who thought about the nature of matter and therefore they did what every chemists does until today: they asked: what does this matter or substance consist of?
Task 1. The Greek word “fýsis” as well as English “nature” could be translated into Czech in two different meanings: 1. příroda, 2. přirozenost, povaha. Look at the text and say which meaning the word “nature” has in each case it is used there.
Ancient Greece
The philosopher Aristotle is sometimes called “the father of western science” because of his great interest in animate and inanimate nature and his quest for logical explanation. But certain important thinkers in Greece preceded Aristotle and Plato and, of course, Socrates (we call them pre-Socratic thinkers). In terms of chemistry there are two important names: Empedocles and Democritus. Empedocles introduces a theory which will be accepted in Europe until the 17th century, the theory of four basic elements. All matter is made up, in differing proportions, of four elemental substances - earth, air, fire and water. Democritus states that all matter is composed of eternal, indivisible, indestructible and infinitely small substances which cling together in different combinations. The Greek word for indivisible is “atomos”. And, as you know, the word is still in use today. Aristotle just used the ideas of his predecessors in a creative way. He suggests that there are two pairs of alternatives - hot and cold, moist and dry - which provide the exact nature of matter. The four possible combinations are the four elements: earth (cold and dry), air (hot and moist), fire (hot and dry), water (cold and moist). But it is the infinitely variable balance between these qualities which creates the different atoms of stone or wood, bone or flesh.
Task 2. Are these statements true or false? Say why.
· The word atom comes from Latin.
· It means the smallest and indestructible, forever existing particle of matter.
· Aristotle was a pre-Socratic philosopher.
Alchemists – Late Antiquity and the Middle Ages
Later, in Hellenistic times Greek knowledge moves to Alexandria. The city is linked with long Egyptian traditions of skilled work in precious metals and people are interested in making practical use of Greek scientific theory. If Aristotle says that the difference in material substances is a matter of balance, then that balance might be changed. Copper might become gold. And that is what occupies the alchemists for almost a thousand years to come. Apart from trying to convert substances they also believed that the elixir of longevity could be produced. The alchemists learned how to use metallic compounds and plant-derived materials to treat diseases. The practical aspect of alchemy generated the basics of modern inorganic chemistry, namely procedures, equipment and the identification and use of many substances. Despite the alchemists' efforts, transmutation of cheap metals to gold never happened and the same is true for the life elixir. The alchemy was also influenced by an old Babylonian tradition of astrology and that is why the alchemists sought relations between metals and planets. Alchemy remains mystical and metaphorical and for sceptical scientific approach which the Greek used to have we must wait until renaissance. But it should be noted here that the Greek legacy was not the only case of scientific achievements in global perspective: In about 1040 the gun powder appears in China. It seems to have been developed in the small chemical laboratories attached to the temples of Taoists where research is conducted mainly on the secret of eternal life.
Task 3. What was the contribution of alchemy for the development of science? How was it different from real science?
The birth of modern science
A book was published in Amsterdam in 1648 which can be seen as a definitive turning point between alchemy and chemistry: Ortus Medicinae (Origin of Medicine) by Jan Baptista van Helmont. Van Helmont still believes in alchemy, but he also conducts experiments on entirely scientific principles. Another important moment is the issue of a book called The Sceptical Chemist by Robert Boyle which appears in 1661. Boyle is properly sceptical about contemporary theories on the nature of matter, which still derive mainly from the Greek theory of four elements. Elements, as he imagines them, are 'corpuscles' of different sorts and sizes which arrange themselves into compounds. Compounds can be broken down into their constituent elements. In 1803 John Dalton´s modern atomic theory appears. And an entirely new story begins.
Task 4. Homework: We did not exhaust the topic at all: the history of chemistry continues! Use encyclopaedia, the internet or books on history of science and try to find out about these problems:
· the phlogiston theory
· the discovery of sub-atomic particles
· vaccum tube, cathode rays, x-rays, radioactivity