530 MEMOIR OF KIRCHHOFF. 



iogly a favorite guest at theeheerfiil meetings of this circle at Haussers 

 friends. But it was with Buiisen particularly that Kirchhoff came into 

 a close connection in the first years of his sojourn at Heidelberg. Bun- 

 sen was his elder by thirteen years ; strong, broad shouldered, of a more 

 vivacious temper and of a more immediate iutiueuce, Bunsen struck 

 with awe one and all bj^ the plenitude of his powers. Thus the two 

 men were in exterior very different from each other. It is a fact how- 

 ever that Bunsen and Kirchhoff not only acconiplished together their 

 great works, but even spent together their bachelor days as true friends. 

 They took trii)S together to the magniflcient environs of Heidelberg, 

 they travelled together during the summer holidays, and even coulil 

 often be seen together of an evening at the small Heidelberg theater, 

 an amusement in whicli Kirchhoff particularly took a great delight 

 from the days of his youth. 



They did not part company, as is usually the case, even when Kirch- 

 hoff, towards the end of the sixth decade of our century, married the 

 young and charming daughter of his Konigsberg Professor Richelot. 

 It was in fact during the years 1859-'02 that the two investigators, start 

 ing from a research of Bunsen, made and accomplished together the 

 great discovery of spectrum analysis. 



Towards the beginning of the seventh decade Kirchhoff moved, at the 

 same time with my father, to the newly erected Frederick Hall, the first 

 great institution in Germany devoted wholly to the furtherance of re- 

 sources in natural science. It was an external nianifestatioji of the fact 

 that the center of gravity of the Heidelberg University gradually 

 shifted from law and history to natural science and medicine. The 

 philosopher Zeller, the mathematician Hesse, afterwards Konigsberger, 

 the chemist Kopp, the clinician Frietlreich, my father as physiologist, 

 all received calls to the institution. The Frederick Hall, became a kind 

 of branch university. In this building I spent the days of my child- 

 hood; Kirchhoff"'s apartments, as well as the apartments of my parents 

 under them, and the whole Frederick Hall, coalesce into one image in 

 my memory. Large lecture-rooms and museums, with enigmatical 



ological names, stuffed animals, chemical and anatomical smells, 



acoustic sounds, then crowds of students (Russian laily students among 

 them) overfloodiug at regular intervals the passages and the yards, to 

 the great annoyance of children, while going to hear lectures by their 

 (the annoyed children's) fathers, — these are the impressions that time 

 has left me. 



Kirchhoff spent there happy years. His name was already famous 

 through his discovei> of spectrum analysis, so that liis laboratory and 

 his lectures became the most frequented ones. With his wife, his four 

 children, and his nearest friends, he led a happ}' life made cheerful 

 through convivial intercourse. 



Unfortunately these in every respect pleasant circumstances came to 

 an end already towards the close of the seventh decade. In consequeuce 



