(Eaglesfield, Great Britain, 1766-Manchester, 1844) British chemist and physicist. In his childhood with his brother helped his father in farm work and small family store where woven dresses, while her sister Mary helped her mother with the housework and selling paper, ink and pens. Although
economic situation was quite humble, they received some education in the nearest Quaker school, unlike other children in the same condition. The school teacher Pardshow Quaker Jonh Dalton Hall provided a good basis and transmitted desire for relentless pursuit of new knowledge. A rich Quaker, Elihu Robinson, became his mentor and another source of stimulation to mathematics and science (especially the weather).
With only 12 years old Jonh Dalton opened a school in his hometown, Eaglesfield. Although he learned to handle problems with students older than him, after two years had to abandon his project due to low pay, and had to return to work in the fields working for an uncle. Jonh Dalton
In 1781 he joined his brother as an assistant to George Bewley in school Kendall. When George retired, he and his brother opened their own school, where classes offered English, Latin, Greek and French, in addition to 21 issues related to mathematics and science. Her sister moved with them to help around the house. Despite having about 60 students, sometimes they had to work to keep auxiliary tasks.
John Gough, the blind son of a wealthy merchant, he became friends with John Dalton and his mentor. He taught languages mathematics and optics, and share your library with Dalton. Dalton's interest extended into the air, astronomy and geography, and in 1787 began lecturing extraordinary income. He also went to a nearby museum with an offer to sell classified eleven volumes of his botanical collection. He collected butterflies and studying the snails, ticks and worms. Also measured their food intake and compared it with the waste produced by your body. Preparing their entry into medical school, but his family discouraged by lack of money and trust in him.
At the age of 26 years (1792), Dalton found that neither he nor his brother were able to distinguish colors. His mother gave him a half (which he believed blue) and she asked in surprise what was the reason that gave scarlet stockings, that it was inappropriate for a Quaker. In his first important scientific paper, John Dalton gave a scientific description of this phenomenon later became known by the name of colorblindness.
In 1793, he moved to Manchester as a tutor at the New College founded by the Presbyterians. Immediately enrolled at the Manchester Library and Philosophical Society (which would chair). In the same year Dalton published his first book, Meteorological Observations and Essays, where he defended the thesis that the air is a physical mixture of gases rather than a chemical combination. As a chemistry tutor knew the work of Lavoisier.
In 1802 he established his law of partial pressures (Dalton's Law). When two elastic fluids A and B are mixed, there is repulsion between particle A and a B, but between one particle and another particle B B. It also established a relationship between vapor pressure and temperature. His interest in the gases derived from his fondness for meteorological studies: Always carry equipment of the time where was, performing throughout his life over two hundred thousand observations consistently noted in his diary. These observations, his analytical mind could find numerical relations between data.
In 1803, while trying to explain his law of partial pressures, began to make his greatest contribution to science: the atomic theory. Was studying the reaction of nitric oxide with oxygen when he discovered that the reaction could take place with two different proportions: sometimes 1:1,7 and other 1, 3.4 (by weight). This led to Dalton to establish the law of multiple proportions, which states that the weights of two elements always combine with another in small whole number ratios. In the same year he published his first list of atomic weights and symbols.
The results were communicated orally and in a book published in 1808, his most famous work: A New System of Chemical Philosophy, Part I. It adopted the idea of \u200b\u200bindividual atoms and particles drawn to illustrate the chemical reactions. Not everyone accepted the new theory and in 1810 published the second part, providing new empirical evidence.
Although he was a member of the Royal Society since 1822 and in 1825 received the medal of the scientific society for his work in atomic theory, Dalton was always considered himself primarily a teacher, who earned a living by giving classes and lectures until 1933, when he was awarded an annual civil pension. On July 27, 1844 died of a heart attack. According to his wish, after his death an autopsy was performed to determine the cause of what was later called color blindness. His latest experiment showed that the blindness is not a problem of the eye itself, but was caused by a deficiency of sensorial power. He was buried with honors from the monarch, at a funeral followed by more than four hundred thousand people, contrary to the principles of the Quakers under which he lived.
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