# Charles's law

Charles's law states that

$\left. \frac{V}{T}\right\vert_P=k$

where $V$ is the volume, $T$ is the temperature and $k$ is a constant. This holds true for an ideal gas.

## History

Charles's law was apparently discovered by Jacques Alexandre César Charles in 1787, as mentioned by Joseph Louis Gay-Lussac (Ref. 1):

"Although I had recognized on many occasions that the gases oxygen, nitrogen, hydrogen, carbonic acid, and atmospheric air all expand identically from 0° to 80°, citizen Charles had noticed the same property in these gases 15 years ago; however, since he never published his results, it is only by great luck that I knew it."

## References

1. Joseph-Louis Gay-Lussac "The Expansion of Gases by Heat", Annales de Chimie 43 pp. 137- (1802)