John Dalton

1994/11/01 Azkune Mendia, Iñaki - Elhuyar Fundazioa Iturria: Elhuyar aldizkaria

• Biografiak

This English chemist moved to Eaglesfield in Cumberland on 6 September 1766. His parents were cuaqueros and his son John was so during his life. With only twelve years, he had to practice as a teacher in a school of cuaqueros and then the tendency to scientific issues arose.

The first field was meteorology, inventing and manufacturing the instruments themselves. In 1793 he wrote the book “Observations and Meteorological Essays”, one of the first on meteorology. Although Dalton took care of chemistry, he continued to collect weather data for forty-six years until his death.

Dalton realized that human sight sometimes does not distinguish colors, as Dalton had that disease. That's why this color blindness is sometimes called dychromatopsis or color blindness. However, in 1794 he released this disease.

Since then Dalton worked in the field of chemistry, but the truth is that not differentiating colors is a great obstacle for the chemist, since in the laboratory it needs it.

Dalton did not highlight his chemical essays, nor the conferences that were very fashionable at the time. Dalton gained fame for his interpretation of facts. As for the gases, he certainly said they were composed of particles. He formulated the “Dalton Partial Pressure Act.” This law establishes that the pressure exerted by each of the components in a mixture of gases is what would take place if the temperature remained the same, if the gas reached the entire volume.

However, Dalton extended the particularized character of the gases to the rest of the matter. The law of definite proportions, announced by Proust, indicates that if a compound contained two elements in a proportion of one in three, it would never have had them in a ratio of 3.1/1 or 2.9/1. This law is easily understood if the compound is considered to consist of indivisible particles. If the particle of one element weighs three times more than that of the other and the compound consists of one element of each, the weight ratio is always one in three and never 3.1/1 or 2.9/1.

Based on this, in 1803 Dalton announced the law of multiple proportions. Democritus clearly saw that it was similar to the theories expressed twenty-one centuries earlier, so he called indivisible particles “atoms” because Democritus used this word. However, it was Dalton's chemical theory and Democrrito's philosophical theory.

According to Dalton, all known substances were formed by different combinations of atoms. He also said that the atoms of one element were exactly the same, although they were different from the atoms of another element. He said they were different in mass, enunciating for the first time quantitative atomic theory. The first table of atomic weights was also the same. In 1808 he published the work entitled “New System of Chemical Philosophy”, in which he expounded all his theory.

In 1810 he wanted to take part in the Royal Society, but Dalton did not accept it because it was cuacero. In 1831 he collaborated in the creation of the British Association for the Progress of Science and in 1832 he was given the title of Doctor in Oxford.

He died on 27 July 1844 in Manchester.