John Dalton, The British scientist

John Dalton was the British scientist who in the early 19th century, put forward the hypothesis of atoms into the science arena. With this act, he presents the key ideas that enable major advances in the field of chemistry since that time.
To be clear, he was not the first person to assume that all material objects consist of a large number of very small particles and not destroyer
called atoms. This opinion has been filed by the ancient Greek philosopher, Democritus (360-370 BC?), Maybe even early again. The hypothesis was accepted by Epicurus (Greek philosopher others), and brilliantly put forward by Roman writers, Lucretius (died 55 BC), in which he has a famous poem "De rerum natura" (About the nature of things).

The theory of Democritus (who is not accepted by Aristotle) is not ignored people during the Middle Ages, and have little influence on science. Even so, some leading scientists of the 17th century (including Isaac Newton) supports a similar opinion. However, no atomic theory proposed or used in scientific investigation. And more importantly, no one who saw a connection between philosophical speculation about the atom with the real things in the field of chemistry.

That is the situation when Dalton appeared. He presents "quantitative theory" a clear and straight that can be used in the interpretation of chemical experiments, and can be tested directly in the laboratory.

Although the terminology is slightly different from the one we use now, Dalton clearly express the concept of atoms, molecules, elements and chemical mixtures. He was clear that although the total number of atoms in the world so much, but the number of various different types rather small. (The book notes the original 20 elements or groups of atoms; now slightly over 100 elements are known).

Despite differences of different types of heavy atoms, Dalton still think that every two atoms of similar groups is the same in all of its quality, including the "mass" (the quantity of material in an object measured by resistance to change in motion). Dalton put in his book that records a list of the relative weight of various types of atoms are different, the first list of people who had prepared and the key to any quantitative theory of the atom.

Dalton also explained clearly that each of two molecules of the same chemical combination consists of a combination of similar atoms. (For example, each molecule "nitrous oxide (N2O) consists of two nitrogen atoms and one oxygen atom). From here to form a chemical combination of certain things - no matter how prepared or where it obtained - always consist of the same elements in the proportion of completely equal weight. This is the "law of proportion must be," which have been found in eksperimentil by Joseph Louis Proust first few years.

Dalton was so convincing I present the theory, so that within twenty years he was accepted by the majority of scientists. Furthermore, chemical experts, the program proposed by the book: specify the precise relative atomic weight; chemical analysis of the combined weight; determine the right combination of atoms that make up each group of molecules that have a common feature. The success of this program is certainly remarkable.

List of Dalton's atomic weights
It is excessively difficult to express the significance of the atomic hypothesis. This is the central opinion in our understanding of the field of chemistry. Additionally, it is essential from the general introduction of modern physics. Just because peratoman problems so often discussed before Dalton so he could not place higher in the order of this book list.


Table elements and combinations of John Dalton
Dalton was born in 1766 in the village of Eaglesfield in the North of England. Formal school only ended when a new age of seven years, and he was almost entirely self-taught in science. He was a young man who always understood something earlier than the average normal person, and when he reached the age of twelve she had become a teacher. And he became a teacher or private teacher for most of his life. When he was fifteen years increased he moved to the town of Kendal, the age of twenty-six to Manchester and stayed there until the breath out of his throat in 1844. May need to know, he never married.

Dalton became interested in meteorology in 1787 when he was twenty one years. Six years later he published a book on the subject. Investigations of atmospheric air and generate interest in the gas quality in general. With a series of experiments, he found two laws that control the behavior of gases. First, Dalton presented in 1801, asserted that the volume of gas is filled proporsiona1 with temperature. (This is commonly known as "Charles Law" after the French scientist who discovered a few years before Dalton, but failed to publish the results of the investigation). Second, also served in 1801, known as "Dalton's law" of pressure parts per part.

By the year 1804, Dalton had formulated a theory he has prepared a list of atoms and atomic weight. However, the main book A New System of Chemical Philosophy, published in 1808 only. This book made him famous, and in subsequent years, interest sows award above his head.

By coincidence, Dalton suffered a type of color blindness disease. The situation is even aroused the desire him. He studied the problem, and publish scientific papers about the color blind, a topic which was written the first time! Michael H. Hart,One hundred most influential figures in the history.