History Of Chemistry

Activity chemistry.

2000 BCE

the activity is a measure of an "effective concentration" of a species. It arises because the molecules in a gas or not ideal solution interact with each other. The activity has no dimensions. It is made dimensionless using the molar ratio for its calculation. The activity depends on temperature, pressure, and composition. For gases, the effective partial pressure is usually referred to as fugacity.

Chemistry today

2000 BCE

During the 20th century the growth of chemical activity has been exponential. New chemical knowledge are used in the manufacture of all kinds of plastic materials, medicines, cosmetics, cleaning products, lubricants, paints, fertilizers, explosives, synthetic fibres, new fuels, metal alloys for aviation, etc. Scientists have investigated the metabolism of the cells, the reactions in water courses, in the air and on the ground. It is impossible to describe all of this in a few pages.

Modern chemistry

1950 BCE

The chemical elements have an extraterrestrial origin. The most basic, hydrogen and helium, originated in the Big Bang. The rest did in fusion reactions inside stars (where also you get helium "burning" hydrogen) and the heavier than iron, in supernova explosions. It is the death of the star that the elements "cooked" by them are released into the interstellar medium and are available for future use: new stars, asteroids, planets, human beings...

Phlogiston

1635 BCE

Johann Becher proposed a particular version of the theory of the four elements: the key role was reserved to the land and water, while fire and air were considered as simple transformations. All the bodies, animal, vegetable and mineral, were formed according to Becher by mixtures of water and Earth.

Iatrochemistry.

1525 BCE

is a branch of both chemistry and medicine. The word "iatro" was the Greek word for "physician" or "medicine." Having its roots in alchemy, iatrochemistry seeks to provide chemical solutions to diseases and medical ailments. This area of science has fallen out of use in Europe since the rise of modern establishment medicine. However, iatrochemistry was popular between 1525 and 1660, especially in Flanders. Its most notable leader was Paracelsus, an important Swiss alchemist of the 16th century.

Alchemy.

400 BCE

It was during this time that the roots of alchemy grew. The Greeks of Egypt are regarded as the forefathers of attempts to change valueless metals into metals of greater value (e.g. iron into gold). In the fourth century B.C, Zosimos the Greek described a substance called Xerion, a metal that supposedly turned other metals into gold. One needed to add a little dab of Xerion to a pile of metal and after two hundred years, the metal would have become gold.

Discovery of fire.

1 BCE

Lightning callus and impact in a dry trunk causing the wood to create fire, humans were very surprised.