John Dalton was a British chemist, physicist, and meteorologist who developed the atomic theory, and studied the concept of color blindness (Daltonism).

Dalton was born on the 6th of September 1766 to a weaver and his wife in Cumberland, England.

During his early life he worked at a school hear his home and then moved to Manchester to further his education.

He was quite close to a very knowledgeable man, John Gough, who taught Dalton many things about science, mathematics and philosophy.

He began teaching maths and philosophy, and later moved onto private tutoring as his college was going through many difficulties.

During Dalton’s life, he was influenced by some great personalities just like Gough. Elihu Robinson was one such man.

Robinson was a meteorologist and an instrument maker and got Dalton interested in these disciplines, and maths.

Dalton learned much during this time, especially related to the weather, and it set the foundation for his future work in the area.

Dalton’s work in colour blindness, now referred to as “Daltonism” in his honour led him to talk about the eye condition that makes it difficult to identify colours.

He believed that a problem in the liquid of the eyeball made it difficult for people having this condition to be able to identify colors.

He himself suffered from a type of colour blindness and unfortunately, his theory was not widely accepted during his time.

He wrote many academic papers on Daltonism, and other topics from rain, dew, springs, heat, and topics related to vision during his lifetime.

However, Dalton’s atomic theory really made him famous. Dalton was not the first to propose the existence of atoms but his theory is special for many reasons.

Other theorists only claimed that atoms existed. Dalton went further to explain that atomic matter had weight, and that atomic elements were identifiable based on their weight.

According to his theory, all elements are made out of tiny particles called atoms; atoms of the same element are identical in size, weight and other properties.

Similarly, atoms of different elements are different based on their relative weights, atoms cannot be divided into a smaller size, and atoms cannot be destroyed.

Furthermore, the chemical reactions we observe is because atoms are rearranged, separated, or combined in some way.

Atoms combine as whole numbers, for example 1:1, 1:2, and 2:3. He also found that when two or more atoms made of different elements combined a chemical compound was made.

Even though people took a bit of time to accept his atomic theory, by the end of his life his theory was widely accepted.

The weather observations Dalton made were done using instruments he had made himself.

These observations were recorded in his book Meteorological Observations & Essays in 1793, which was one of the first books of its kind.

Since he was a teacher for the most part of his life, he published books on many topics including English.

His observations and discoveries on the atomic theory laid the foundations for future scientists and physicists like Eugen Goldstein (discovered positive charged particles in atoms), J.J. Thomson (discovered electrons), and Rutherford (discovered that atoms were made up of a dense positive core called the nucleus and was surrounded by electrons) and many more to make their own discoveries.

Dalton was presented with many medals and awards for his work. He never married and lived a very humble life even though he was quite famous.

Towards the end of his life, he suffered a few strokes that left him unable to speak, and move his hands. He was found dead in his room after falling out of his bed on the 27th of July 1844.