Dalton's Law

Dalton's interest in atmospheric pressures eventually led him to a closer examination of gases. While studying the nature and chemical makeup of air in the early 1800's, Dalton learned that it was not a chemical solvent, as other scientists had believed. Instead it was a mechanical system composed of small individual particles that used pressure applied by each gas independently.

Dalton's experiments on gases led to his discovery that the total pressure of a mixture of gases amounted to the sum of the partial pressures that each individual gas exerted while occupying the same space.