Start Encyclopedia69 Dictionary | Overview | Topics | Groups | Categories | Bookmark this page.
dictionary -  encyclopedia  
Full text search :        
   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z   #   




  Modern chemistry has its origins in the practice of alchemy, which is over 6,000 years old. Alchemy was first practised in the Nile Delta, where it was discovered that the action of heat on minerals isolated the metal from the ore. Alchemy then spread throughout the Middle East and into Asia. One of its aims was to find the philosopher\'s stone which would convert base metals into the ‘noble metal’ gold. The philosopher\'s stone proved elusive, but the experimentation involved in trying to find it paved the way for modern chemistry. By the 12th century the availability of Arab writings on the subject of alchemy gradually led to the scientific study of chemical processes and reactions. With the publication of Robert Boyle\'s (1627 - 1691) Sceptical Chemist, and his hypothesis that matter consisted of simple bodies, the science of chemistry was finally established.

During the 18th century various scientists, including Joseph Black and Henry Cavendish, began the systematic study of various elements and their compounds. Work by Antoine Lavoisier, the so-called founder of modern chemistry, demonstrated that any burning substance combines with oxygen. Among his other work Lavoisier undertook finally to separate alchemy and chemistry, by carrying out a wide-ranging series of experiments, and this is indeed what he achieved.

Lavoisier\'s new system was built on the concept of chemical elements, on which he derived a new nomenclature which scientists still use today. Once accepted, his theories gave chemists plenty to do. The introduction of John Dalton\'s atomic theory in the late 18th century made Lavoisier\'s theories even more exact; now that chemistry was logically based on sound principles, its progress was rapid.

Chemistry today can be broadly split into three main branches: organic chemistry (the study of carbon compounds) based originally on materials produced by living organisms, that is, bacteria, plants and animals; inorganic chemistry (the study of substances of mineral origin); and physical chemistry.

Because of the scarcity of some vegetable sources, and the variability of their quality, chemistry has been utilized to synthesize the complex molecules of some drugs. Originally ‘synthetic’ denoted a poor substitute but now it refers to the pure forms of drugs. The derogatory implication of ‘synthetic’ arose in the early use of fibrous manufacture from mineral oil bases. Nylon, being a simple fibre with little water absorption, could not reproduce the ‘feel’ of cotton and wool fabrics. Developments of new fabrics and changes in production of the fibres and methods of weaving now allow such desirable characteristics to be developed that ‘synthetic’ fibres are sometimes better than ‘natural’.

In early civilization vegetable dyes were used to colour fabrics but the wide range of bright colours now used depends on a wide range synthesized from basic chemical materials. AA

See also catalysts; chemical compounds; metals and alloys; periodic table; science; scientific method.



Bookmark this page:



<< former term
next term >>
Chemical Compounds
Chicago School


Other Terms : Transcendental Arguments | Time-Space Compression | Language
Home |  Add new article  |  Your List |  Tools |  Become an Editor |  Tell a Friend |  Links |  Awards |  Testimonials |  Press |  News |  About |
Copyright ©2009 GeoDZ. All rights reserved.  Terms of Use  |  Privacy Policy  |  Contact Us