John Dalton Biography and Facts

Dalton - Famous Chemist, Physicist and Meterologist

John Dalton was an English chemist and physicist, best known for his atomic theory and research about color blindness.
John Dalton was an English chemist and physicist, best known for his atomic theory and research about color blindness. De Agostini Picture Library / Getty Images

John Dalton was a renowned English chemist, physicist and meteorologist. His most famous contributions were his atomic theory and color blindness research.

Fast Facts: John Dalton

  • Born: September 6, 1766 in Eaglesfield, Cumberland, England
  • Died: July 27, 1844 (age 77) in Manchester, England
  • Occupation: chemist, physicist and meteorologist.
  • Key Accomplishments: Atomic theory and color blindness research.
  • Awards: The Royal Medal (1826)

Dalton was born into a Quaker family. He learned from his father, a weaver, and from Quaker John Fletcher, who taught at a private school. John Dalton started working for a living when he was 10 years old. He began teaching at a local school when he was 12. John and his brother ran a Quaker school. He could not attend an English university because he was a Dissenter (opposed to being required to join the Church of England), so he learned about science informally from John Gough. Dalton became a mathematics and natural philosophy teacher at age 27 at a dissenting academy in Manchester. He resigned at age 34 and became a private tutor.

Scientific Discoveries and Contributions

John Dalton actually published in a variety of fields, including mathematics and English grammar, but he is best known for his science.

  • Dalton kept meticulous daily weather records. He rediscovered the Hadley cell theory of atmospheric circulation. He believed air consisted of about 80% nitrogen and 20% oxygen, unlike most of his peers, who thought air was its own compound. 
  • Dalton and his brother were both color blind, but color blindness had not been officially discussed or studied. He thought the color perception might be due to a discoloration inside the liquid of the eye. He believed there was a hereditary component to red-green color blindness. Although his theory about discolored liquid did not pan out, color blindness became known as Daltonism.
  • John Dalton wrote a series of papers describing gas laws. His law on partial pressure became known as Dalton's Law.
  • Dalton published the first table of relative atomic weights of atoms of the elements. The table contained six elements, with weights relative to that of hydrogen.
  • Dalton's atomic theory may be his most famous work. He was trying to understand how the law of multiple proportions worked. The key points of Dalton's atomic theory are.
    • Elements are made of tiny particles, which he called atoms.
    • Atoms of one element are exactly the same size and mass as other atoms of that element.
    • Atoms of different elements are different sizes and masses from each other.
    • Atoms can't be further subdivided, nor may they be created or destroyed.
    • Atoms rearrange during chemical reactions. They may be separated from each other or combined with other atoms.
    • Atoms form chemical compounds by combining with each other in simple whole number ratios.
    • Atoms combine according to the "rule of greatest simplicity", which says if atoms only combine in one ratio, it must be a binary one.

    Some points of Dalton's atomic theory have been shown to be false. For example, atoms may be created and split using fusion and fission (although these are nuclear processes and Dalton's theory does hold for chemical reactions). Another deviation from the theory is that isotopes of atoms of a single element may be different from each other (isotopes were unknown in Dalton's time). Overall, the theory was immensely powerful. The concept of atoms of elements endures to the present day.

    Interesting John Dalton Facts

    • One of Dalton's students was James Prescott Joule, a famous physicist.
    • In 1810, Sir Humphy Davy personally asked John Dalton to apply to the Royal Society, but Dalton declined. However, in 1822, he was made a candidate without his knowledge and did join.
    • Dalton did not marry. He had a few close friends, generally living a quiet and modest life.
    • From 1837 until his death, Dalton suffered a series of strokes. He continued to work until the day he died, supposedly recording a meteorological measurement on July 26, 1844. On the 27th, an attendant found him dead beside his bed.