184 BIOGRAPHIES OF SCIENTIFIC MEN 



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, Lemons 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'etat of Napoleon III. 



Among posthumous honours, there is the Lycee Gay- 

 Lussac at Limoges, and the Rue Gay-Lussac, Paris, near 

 the Pantheon 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." 



