PROFESSOR AT HEIDELBERG 275 



On April 4, 1870, du Bois-Reymond informed him of the 

 death of Magnus, adding : ' I could tear my hair now for not 

 having gone to the Minister when there was the question of 

 Bonn, and begging him to let me conduct the negotiations with 

 Prussia for you. If you were only in the Chair of Physics 

 at Bonn, it would be a much easier matter to get you ap- 

 pointed to succeed Magnus at Berlin/ . . . 



Helmholtz replied on April 7 : 'I do not reckon too much 

 on a call to Berlin, because I think Kirchhoffs appointment is 

 much more on the cards, and would be easier to arrange. 

 He is well in health now, is bright and energetic, and hardly 

 wants his crutches even where the ground is not level. What 

 you want in Berlin above all is a mathematical physicist, and 

 I must say that Kirchhoff is a trained and practised force in 

 that field, which I am not, however good the opinion I may 

 have of my own deserts in other respects. I should be con- 

 tent to be his successor here.' 



Helmholtz indeed contemplated the eventuality of his call 

 to Berlin with great calmness. While his wife's clear judge- 

 ment and intellectual vigour soon recognized that the stirring 

 life of art and science in Berlin would afford a very different 

 scope for her husband's work and her own talents to that of 

 Heidelberg, for Helmholtz it was only a question of being 

 able to devote his entire activities in teaching and research 

 to physics. He replies on May 7 to Borchardt's congratu- 

 lations on his own and Kirchhoff's election to the external 

 membership of the Academy. * ... If fate should so dispose 

 that one of us should not long be an external member I should 

 greatly rejoice, because it would give me the opportunity of 

 devoting myself to physics. But between physics in Berlin and 

 physics in Heidelberg the balance is so nicely weighted, that 

 I don't yet know where it will come to rest when its oscil- 

 lations are over, and can calmly await the decision of the gods 

 and of Herr von Muhler ; and I believe Kirchhoff is much in 

 the same mind.' Meantime the possibility of Helmholtz's call 

 to Berlin was rumoured in the papers, and on May i the 

 Minister Jolly came to assure him that he should leave 

 nothing in his power undone to make his attachment to 

 Heidelberg permanent, and to comply in every way with his 

 wishes. 



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