John Dalton was born in Eaglesfield, England, to a Quaker family. He attended a Quaker school and became a math and philosophy tutor at the New College in Manchester. He then joined the Manchester Literary and Philosophical Society and pursued his interest in meteorology. He also researched color blindness, which he theorized was hereditary and proved to be true when genetic analysis of his own eye tissue revealed that he was missing the photoreceptor for perceiving the color green. His interest in atmospheric pressures eventually led him to a closer examination of gases, discovering that air was a mechanical system composed of small individual particles that used pressure applied by each gas independently.
Dalton's Law of Partial Pressures is a scientific principle that states that the total pressure of a mixture of gases is the sum of the partial pressures that each individual gas exerted while occupying the same space. It can be demonstrated using a simple experiment involving a glass bottle and a large bowl of water. It has many practical applications today, such as scuba divers using it to gauge pressure levels at different depths of the ocean. John Dalton was an international chemist who discovered the atomic theory in 1844. His research changed the face of chemistry and initiated its progression into modern science.