318 BERTHOLLET. 



Paris, giving to each the portion for which his tastes and 

 studies had fitted him. No city in the world was ever 

 so rich in men of science, as Paris was then, and all these 

 men were Humboldt's personal friends. He was ac- 

 quainted with most of them before he started on bis 

 travels: when he returned, opulent in knowledge and 

 experience, his acquaintance was sought by the rest. 

 Among his friends at this time, and for years afterwards, 

 in fact till the close of their lives, for Humboldt never 

 lost a friend, except by death, we may mention Biot, 

 Gay-Lussac, Latreille, Cuvier, Laplace, Arago, and Ber- 

 thollet. Arago and Gay-Lussac were the youngest of 

 the band, the former being in his twenty-second year, the 

 latter in his twenty-ninth. The oldest were Laplace and 

 Berthollet, both of whom were within a few months of 

 fifty-nine. Cuvier was born in the same year with Hum- 

 boldt, and like him was thirty-eight. 



Claude Louis Berthollet was born at Talloire, in 

 Savoy, on the 9th of December, 1748. Eeceiving his 

 early education at Chambery, he entered the university 

 of Turin, where he obtained a diploma as doctor of medi- 

 cine. Armed with this formidable weapon he came to 

 Paris, and was fortunate enough to be appointed physi- 

 cian to the Duke of Orleans. While holding this situa- 

 tion he devoted himself to the study of chemistry, and 

 published his "Essays," which made him favourably 

 known in the world of letters. The influence of the 

 Duke procured for him, some years later, the office of 

 government commissary, and superintendent of dyeing 

 processes. This led him to write a work on the theory 

 and practice of dyeing. He was soon after engaged in 

 another kind of dying, or rather trying to help the 



