Xehemester in hindi


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.

The history of alchemy represents a time span from ancient history to the present.

By 1000 BC, civilizations used technologies that would eventually form the basis of the various branches of chemistry.

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.