The law, depending on which scientist you believe first came up with the idea, states that by heating a gas, its volume changes exponentially.

According to scientific legend, Alexandre C. Charles chatted with a French colleague, Joseph Gay-Lussac, about experiments Charles was doing with heating gases. Charles stated that he had found out that if one heated a gas to say, three times its original temperature, the gas's volume tripled. Charles talked about the results of his experiments holding true each time BUT HE DIDN'T PUBLISH THE RESULTS. Gay-Lussac, performed his own experiments, reached the same results, and in 1802, published this theory, calling it Gay-Lussac's Law.