Chemistry plays an important role in our understanding and use of material, the universe is made of matter composed of the chemical is one of the ways and means of human beings to understand and transform the material world, it is a long history and a vibrant it is a very close relationship with human progress and social development, its achievement is an important symbol of social civilization. Primitive society, the use of fire from the beginning to use a variety of man-made substances in modern society, human beings are to enjoy the chemical results. Human life can continue to improve and improve the contribution of the chemical which played an important role. Chemical experiment equipment The chemical is one of the important basic science, and mutual penetration of the disciplines of physics, biology, geography, astronomy, and a rapid development, but also to promote the development of other disciplines and techniques. For example, the nucleic acid chemistry research, today's biology from the cellular level to molecular level, the establishment of molecular biology; analysis of chemical composition of stars obtained the distribution of elements of the law and found that a simple interstellar space compounds in the presence of celestial evolution and modern cosmology science provides experimental data, but also to enrich the contents of the dialectics of nature. 16th century European industrial production is booming, and promote the creation and development of pharmaceutical chemistry and metallurgy chemistry and alchemy towards life and the practical application of, and then pay more attention to the study of the material and chemical changes. Elements of the scientific concept of precise experimental study of combustion phenomena, the establishment of scientific oxidation theory and the law of conservation of mass, and subsequently established the law of definite proportions, times more than the law and the combined amount of law for the chemical to further scientific development laid the foundation. Quantitative chemical experiments after 1775 years ago, Lavoisier explained combustion oxidation doctrine, creating a period of quantitative chemical, the chemical on the right track. Early 19th century, the British chemist Dalton proposed the modern atomic theory, highlighted the atomic mass of the various elements of its basic characteristics, the introduction of the concept of which the amount is a major difference with the ancient atomism. Modern atomic theory of chemical knowledge and theory to get a reasonable explanation, a unified theory to explain chemical phenomena. Followed by Italian scientists Avogadro molecular concepts. Since the atomic - molecular theory to study the chemical, the chemical is truly established as a science. This period, the establishment of many chemical fundamental laws. Russian chemist Dmitri Mendeleev discovered the periodic law of elements, the German chemist Lee Liebig and Wheeler, the development of the organic structure theory, which have allowed the chemical to become a system of science, but also laid the foundation for the development of modern chemistry.