EULOGY ON GAY-LUSSAC. 141 



ceeded in maintaining himself in Paris without imposing fresh sacri- 

 fices on his family. 



Gay-Lnssac was one of the most distinguished of the scholars of the 

 Polytechnic School, as, at a later period, he was one of the most illustri- 

 ous and popular of the professors. 



DEBUT OF GAY-LUSSAC IN CHEMISTRY — HE BECOMES COLLABORATOR 

 OF BERTHOLLET AND ASSISTANT PROFESSOR OF THE FOURCROY 

 COURSE — AERONAUTIC VOYAGE WITH M. BIRT. 



Berthollet, who had returned from Egypt with General Bonaparte, 

 requested, in 1800, a pupil from the Polytechnic School, whom he wished 

 to make his aid in the work of the laboratory. Gay-Lussac was this 

 privileged pupil. Berthollet suggested to him an investigation whose 

 results were diametrically opposite to those expected by the illustrious 

 chemist. I could not venture to affirm that Berthollet was not some- 

 what disturbed at finding himself mistaken in his predictions, but it is 

 certain that, unlike many other scientists whom I could name, after the 

 first impulse of vexation, the frankness of the young experimentalist 

 only served to increase the esteem that the author of Static Chemistry 

 had already conceived for him. "Young man," said he to him, "your 

 destiny is to make discoveries ; henceforth you shall be my collabora- 

 tor. 1 desire, and it is a title of which one day I am sure I shall be 

 able to boast, I desire to be your father in matters of science." 



Some time afterward, without giving up his position with M. 

 Berthollet, Gay-Lussac was chosen assistant professor of the Fourcroy 

 course and often supplied Berthollet's place, which soon gained him 

 the reputation, that was constantly growing, of one of the most distin- 

 guished among the very able professors at that time collected at the 

 capital. 



Man, by reason of his weight and limited muscular force, seemed con- 

 demned to move forever on the surface of the earth, and only to be able 

 to study the physical properties of the elevated regions of our atmos- 

 phere by painfully climbing to the summit of mountains ; but what are 

 the difficulties over which genius allied to perseverance cannot triumph '? 



A scientist, who was a member of this academy, Montgolfier, calcu- 

 lated that by rarefying, by means of heat, the air contained in a paper 

 balloon of limited size, he would obtain an ascensional force sufficient 

 to raise men, animals, and instruments of all kinds. This idea was 

 partially realized, June 1783, iu the town of Anuonai. The astonished 

 Parisian population saw, November 21, of that same year, the intrepid 

 voyagers, Pilatre de Eoziers and d'Arlandes, sail through the air, sus- 

 pended from a montgoltiere. Another physicist, whom the academy has 

 also numbered among its members, Charles, showed the possibility of 

 making balloons of a varnished material almost impermeable to hydro- 

 gen, the lightest of known gases, which could take the place of heated 



