This interest had developed from his association in his youth with a fellow Quaker, John Gough, who provided Dalton with most of his formal education in the sciences and mathematics.ĭalton developed his atomic theory as a way of trying to answer certain questions about the atmosphere. The impetus for the development of the atomic theory was Dalton's life-long interest in meteorology and the study of gases. He quit classroom teaching in 1800 to provide private instruction in the sciences and mathematics in Manchester, which he did for the balance of his life. He was for a time the equivalent of a high school teacher in Manchester, England. His formal education was spotty and he was basically self-taught. Born into a devout Quaker family in a rural area of northwest England, he was drawn early in life to an interest in the natural sciences. John Dalton (1766-1844) was a most unlikely person to develop the atomic theory. However, their view that matter is particulate signaled an increasing consensus among scientists of the era-a consensus that would make the theory proposed by Dalton much more readily acceptable. As was the case with the Greeks, Boyle, Newton, and others had no evidence to back up their claims. This was used by him to explain why some chemical reactions occurred and others did not. Isaac Newton (1642-1727) in his Opticks (1704) also proposed a particulate view of matter, and he further proposed that there were strong short range forces that existed between these particles that could be of an attractive or repulsive nature. What differentiated these different types matter was their size, shape, and structural pattern. Robert Boyle (1627-1691) in his Skeptical Chemist (1661) proposed that all matter is composed of solid particles that can be rearranged to form new substances. A revival of atomism would have to wait until the rise of experimental science in the seventeenth century. By the Middle Ages such an explanation was rejected because it introduced the possibility that human actions were not set in motion by a divine being. Finally, if matter was made up of atoms, then a purely mechanical explanation of human actions and behavior would be possible. If matter was particulate, then there would be spaces or voids between matter, which would make motion impossible. This was in direct conflict with the idea of the four elements-earth, air, fire, and water-being the primary building blocks of everything on Earth. The concept of atoms would also mean that there were possibly an infinite number of primary substances in nature. The atomic concept was rejected by most Greek philosophers, particularly Aristotle (384-322 b.c.), because of the paradox that these atoms had no sensible properties-yet they had to be responsible for all the properties of matter that one could sense, such as an object being hot. These ideas, though interesting, could not be considered a scientific theory. The atomic theory of the Greek philosophers lacked any evidence based upon observation, measurements, and testing by experiment. 460-370 b.c.) proposed that matter was composed of individual indestructible particles (called "atoms" in Greek for "uncuttable") and that the size and shape of these particles were responsible for the properties of matter. The concept that matter may ultimately be composed of particles originated in Greek natural philosophy. The atomic theory of matter as proposed by John Dalton in his New System of Chemical Philosophy (Part I,1808 Part II,1810) was the first successful attempt to solve this problem. However, to fully understand the nature of chemical reactions one needed to have a way to visualize how the elements combined together. Was matter continuous and therefore had no finer structure or was it discontinuous and thus made of tiny particles? The chemical revolution due to the work of Antoine Lavoisier (1743-1794) and his circle that had occurred in the last two decades of the eighteenth century had clarified the concept of what elements are, developed a comprehensive and consistent vocabulary of chemistry, and led to the introduction of quantitative methods in chemical investigations. John Dalton Proposes His Atomic Theory and Lays the Foundation of Modern Chemistry OverviewĪs the nineteenth century dawned a significant problem that remained in the chemical sciences was the ultimate nature of matter.
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