John Dalton was in his early career as a scientist he also was researching about color blindness. Him and his brother both faced color blindness that is how he started researching on color blindness (John Dalton biography).
Daltons law: he was always interested in the atmospheric pressures and that lead him to examine gasses closer ( John Dalton biography).
When he became a scientist: When Dalton was 26 years old Dalton' became a teacher of mathematics and natural philosophy. Dalton wrote his very first science paper about facts that relate to visions of colors. It was about blindness. Dalton found out that blind people can see colors because of different types of gases. The Aurora Borealis is made up of gas particles.
The law of multiple proportions: The Law of Multiple Proportions is when two elements combine with each other and form more than one compound that weighs one of the element with a fixed weight.
Dalton announced this law in the year 1803. The confirmation of this law was in wide range for the truth but since it consisted of matter and invisible atoms, the theory was confirmed to be true. ( becoming a scientist).
Dalton's Law of Partial Pressure is the total statement pressure of a mixture of gases is equal to the sum of the pressures that each of the gases would exert if they were alone. This law was found in 1803.
Daltonism: Daltonism is another way of saying color-blindness. Color- blindness is found to be a proven fact that people still see colors but with different colors than we do. Say someone sees a red object they would see it as a black object. ( atomic theory biography.com)
Daltons death: Dalton died in 1844 at the age of 77. John Dalton died because of a stroke that happened because about seven years earlier he had a another stroke that made him lose his speech for a year. The doctor predicted another stroke in the next ten year. During his funeral Dalton had 40,000 people attend it. Dalton was also awarded with the Royal
Medal.
Cites http://www.famousscientists.org/john-dalton/ http://www.biography.com/people/john-dalton-9265201