In 1801, John Dalton published the law of partial pressures from his work with ideal gas law relationship: The pressure of a mixture of non reactive gases is equal to the sum of the pressures of all of the constituent gases alone. Mathematically, this can be represented for n species as:
: Pressure = Pressure + Pressure + ... + Pressure
The image of Dalton's journal depicts symbology he used as shorthand to record the path he followed. Among his key journal observations upon mixing unreactive "elastic fluids" (gases) were the following:
*Unlike liquids, heavier gases did not drift to the bottom upon mixing.
*Gas particle identity played no role in determining final pressure (they behaved as if their size was negligible).