152 EULOGY ON GAY-LUSSAC. 



It was in these terms the immortal physicist expressed the caution 

 which should meet all extraordinary facts similar to the pretended phe- 

 nomenon by which his pupil Configliachi hoped to attain a great repu- 

 tation. The remark is peculiarly applicable to facts ascertained by in- 

 struments of a delicacy so extreme as to be influenced by the preseuce, 

 breath, and emanations from the body of the observer. The Voltaic 

 dictum, " I have seen it, but do not believe in it," might have been ap- 

 plied on some recent occasions ; it would have saved science some ret- 

 rograde steps, and certain authors unqualified ridicule. 



On the 14th and 15th of October our travelers crossed Saint Gothard. 

 Gay-Lussac was denied the enjoyment of a spectacle from which he had 

 anticipated much pleasure and instruction, a thick fog concealing from 

 view even the nearest objects for a whole day. He compensated him- 

 self for this disappointment by a minute study of General Puffer's fine 

 relief of Switzerland. 



At Gottingen, November 4, the great naturalist Blumenbach, at that- 

 time full of life and activity, cordially extended the honors of the uni- 

 versity to our young countryman. 



On the 16th of the same month Gay-Lussac arrived at Berlin, where 

 he remained all winter under the roof of M. de Humboldt, kindly wel- 

 comed and appreciated by all the distinguished men of the city ; he 

 passed much of his time in the society of Klaproth, the chemist, and 

 Erman, the physicist. 



Gay-Lussac quitted Berlin in the spring of 1806. He very suddenly 

 determined to leave on learning that the death of Brisson left a vacancy 

 in the Institute, and that he might be chosen to fill the place of the 

 aged physicist. 



In examining now the works of Gay-Lussac's contemporaries who, in 

 1S06, were in a position to contend with him for the vacancy in the 

 Academy of Sciences, it seems astonishing that his preseuce should 

 have been indispensable to his success ; but it is that we forget that at 

 the end of the eighteenth century and beginning of the nineteenth no 

 one was a real physicist unless possessing a valuable collection of in- 

 struments well polished, well varnished, and arranged in glass cases. 

 It was not without trouble that Gay-Lussac, who owned only a few in- 

 struments of research, succeeded in overcoming such prejudices. Let 

 us preserve these memories for the consolation of those who have ex- 

 perienced, or may in the future experience, disappointments in academic 

 elections. 



GAY-LUSSAC'S RESEARCHES ON DILATATIONS. 



A short time before Gay-Lussac, now a member of the institute, had 

 begun to apply his experimental talent to the study of the changes of 

 the elastic force of gases with the temperature, and the formation and 

 diffusion of vapors, the same field of research had been explored in 

 England by an equally clever man, Dalton, numbered by the academy 

 among its eight foreign members. Dalton, although his genius was 



