A Brief History
On September 6, 1803, pioneering atomic theorist John Dalton of England first assigned symbols to represent atoms of various elements. Dalton, born into a Quaker family, is well known among scholars and scientists for his work but has little of the fame and popular recognition accorded many other better known scientists. Although atomic theory is the field of science most associated with Dalton, he also studied and reported on many other areas of scientific inquiry.
Digging Deeper
Dalton was born into a poor family in 1766, and although he did receive an education from his father and from a private school, by the age of 10 he had to contribute to the household income. He may have even landed a job as a teacher at the age of 12 and is claimed to have learned Latin by age 14. His precociousness and high intellect were apparent at an early age. John and his brother founded a school, and although curious and smart, because of being a “dissenter” (religious non-conformist due to his Quaker faith), John was barred from attending English universities and colleges. He studied under a blind philosopher named John Gough, a fellow Quaker with a thirst for knowledge and fascinating historical character in his own right. (Gough was blinded from a smallpox bout at the age of 3.) Not surprisingly, Dalton was influenced in his scientific inquiries by other prominent Quaker thinkers.
Various atoms and molecules as depicted in John Dalton’s A New System of Chemical Philosophy (1808).
John Dalton landed a post at the age of 27 teaching at a “dissenter” university called New College, at Manchester. (The school that would eventually become Harris Manchester College, Oxford after several location changes.) Teaching “natural philosophy” and mathematics, Dalton left after 7 years on the faculty when the school experienced financial difficulties and Dalton turned to teaching private lessons in math and natural philosophy. (Note: “Natural Philosophy” was the study of nature before modern science renamed the field “Natural Science.”)
Along with atomic theory Dalton also performed groundbreaking research and theorizing into other areas of science, including meteorology, for which he kept a diary of weather observations for 57 years, an astounding 200,000 notes. A man of many talents and pursuits, Dalton also published a book on English grammar. Dalton dabbled into such diverse topics as the formation and nature of dew, heat, color, light (refraction and reflection), and hydrospheric phenomena. Dalton studied the measuring of the height of mountains through the novel use of a barometer and is well known for his studies of color (colour to Dalton and other Brits!) including the theory that color blindness was hereditary as both he and his brother suffered from this visual deficiency. In fact, color blindness is sometimes referred to as “Daltonism” and Dalton’s preserved eyeball was scientifically studied in 1995. Dalton studied and reported his findings into many aspects of the properties, composition and behavior of gasses, including pressure, absorption into water and other aspects.
Statue of Dalton by Chantrey.
The field Dalton is best remembered for is atomic theory, a subject hard to describe concisely in a short article such as this (especially for those of us with degrees in liberal arts fields). Dalton focused on gasses as elements and pioneered the idea of atomic weights. His method for determining relative atomic weights (using Hydrogen as the base “1”) was a first in atomic physics. Dalton’s various theories included that elements were made of atoms and atoms combined to form molecules (which he called chemical compounds). Dalton also believed atoms could not be split, otherwise destroyed, or for that matter created. Dalton posited that chemical reactions were the result of atoms combining, separating, and or rearranging. Dalton’s original table of atomic weights contained only 6 common elements, hydrogen, oxygen, nitrogen, carbon, sulfur and phosphorus.
Modern scientists have criticized Dalton’s scientific method as crude, with sometimes inaccurate measurements and a stubborn adherence to his own ideas in the face of contradictory data. Still, his ground breaking work in atomic theory and color blindness alone rank him among the most important of early modern scientists. Dalton suffered strokes in 1837 and 1838 that impaired his speech, though he continued scientific research. A fall from his bed in 1844 resulted in his death at the age of 77. As he had never married, he left no widow or children. His stature as an important man of science was evident by the 40,000 people in attendance at his funeral, including many leading scientists of his day. he is remembered by many statues and buildings named in his honor, as well as a Dalton Medal issued in his name. The “dalton” is a unit of atomic weight used by many chemists and physicists and a township in Ontario, Canada, is named for him. Many Quaker schools bear his name, and even a crater on the Moon is named in his honor! As stated earlier, color blindness is frequently referred to as “Daltonism.”
Example of an Ishihara color test plate. With properly configured computer displays, people with normal vision should see the number “74”. Many people who are color blind see it as “21”, and those with total color blindness may not see any numbers.
Questions for students: Were you already familiar with the life and work of John Dalton? Were you aware of the eclectic nature of his scientific work? How important do you believe this interesting English Quaker of modest living was to modern science? Please feel free to share your thoughts on the subject of John Dalton.
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Historical Evidence
For more information, please see…
Baxter, Roberta. John Dalton and the Development of Atomic Theory (Profiles in Science). Morgan Reynolds Pub, 2013.
John Dalton and the Development of Atomic Theory (Profiles in Science) (Library Binding)
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Kjelle, Marylou and Whiting, Jim. John Dalton and the Atomic Theory (Uncharted, Unexplored, and Unexplained) (Uncharted, Unexplored, and Unexplained: Scientific Advancements of the 19th Century). Mitchell Lane Publishers, 2004.
John Dalton and the Atomic Theory (Uncharted, Unexplored, and Unexplained) (Uncharted, Unexplored, and Unexplained: Scientific Advancements of the 19th Century) (Library Binding)
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The featured image of British physicist and chemist John Dalton (1766-1844) by Charles Turner (1773-1857) after James Lonsdale (1777-1839) is a faithful photographic reproduction of a two-dimensional, public domain work of art. The work of art itself is in the public domain for the following reason: this work is in the public domain in its country of origin and other countries and areas where the copyright term is the author’s life plus 100 years or less. This work is in the public domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1923.
