British naturalist, chemist, mathematician and meteorologist. He was born on September 6, 1766 specifically in Eaglesfield, into a poor family of devoted weavers. At the age of 12 he began teaching elementary education in Cumberland, 7 years later he became director of it and in the early 1780s he did so in Kendal for 12 more years.
In 1972, at the age of 26, he moved to Manchester, where he taught mathematics and natural philosophy at New College.
- In the year 1793 he began his studies on meteorology, compiling over 200,000 annotations throughout his career and that same year he made his observations and meteorological essays public.
- In his studies on meteorology, he developed various measuring instruments and proposed for the first time that the origin of the rain is in the decrease in temperature.
- In this regard, I study the northern lights in the same way, and I determine that they are familiar with the magnetism of the earth. He dedicated himself to studying the disease he suffered, known as achromatopsia and later named color blindness in his honor, and published truly extraordinary facts regarding color vision (1974).
- From 1800 he went on to private education and obtained the position of secretary of the Philosophical and Literary Society of Manchester, which he presided over at the beginning of 1817.
- In 1801 he published the law of partial pressures and multiple proportions. In 1808 he enunciated the atomic theory on which modern physical science is based. In addition to this, it shows that matter is made up of invisible particles called “atoms.”
- In the same way, I devise a scale of chemical symbols , which will later be replaced by the berzelius scale.
- In 1826 he was awarded the gold medal from the Royal Society of London, as well as from the Royal French Academy of Sciences.
He died in Manchester in 1844, at the age of 78. Approximately more than 40,000 people attended his funeral to show their respect to the scientist.
Dalton took as a starting point various experimental evidences known in his time:
- The substances , whether simple or compound, always have the same characteristic properties.
- Elemental substances cannot be composed.
- Mass is maintained in chemical reactions, which came from the French chemist Louis Proust’s law of conservation of mass.
- Chemical elements do not disappear when a compound is created, since decomposition of this can be created.
To explain these facts, he proposed the following hypotheses:
- The mass is discontinuous; It is made up of atoms that are indivisible particles.
- All atoms of the same element are equal, have the same mass and atoms of various elements differ in mass.
- The atoms of different elements are mixed to form atoms compounds.
- Chemical changes are changes in the combinations of atoms with each other, these cannot be created or destroyed.
The atoms that mix to form a compound always do it in the same proportion, it means that none of the atoms made up of the same substance are exactly the same, which will be the law of multiple proportions.