Gay-Lussac did valuable work on vapour densities, vapour tensions, and solubilities. The effect of variation of temperature on the solubility of different salts was very clearly demonstrated by him; and he was the first to have recourse to the graphic method of expressing solubilities.
In addition to numerous memoirs, Gay-Lussac wrote a Cours de Physique, Cours de Chimie, Leçons de Chimie, etc.
His work was a brilliant conglomerate of faits accomplis in the earliest days of modern chemistry and physics. He was a man of extensive learning—homo multarum scientiarum—and was always ready to give the best advice to students and others.
Gay-Lussac received most of the honours that fall to the lot of men of science. He died on 9th May 1850, a hundred and nine days before the death of the "bourgeois king," Louis Philippe, and a year before the coup d'état of Napoleon III.
Among posthumous honours, there is the Lycée Gay-Lussac at Limoges, and the Rue Gay-Lussac, Paris, near the Panthéon and Luxembourg.
In conclusion, "the alchemists were right. There is a philosopher's stone; but the stone is itself a compound of labour, perseverance, and genius, and the gold which it produces is the gold of true knowledge, which shall never grow dim or fade away."