PROFESSOR AT BONN 161 



I feel the need of more profound philosophical knowledge. 

 Schopenhauer I deliver over to you; I disliked what I have 

 read of him/ 



Helmholtz had hardly settled down at Bonn, when proposals 

 were made to him to move to another sphere of action. In 

 April, 1857, Bunsen tells him ' the Baden Ministry are willing 

 to make considerable sacrifices, in order to attract a good 

 physiologist to Heidelberg'. The selected candidates were all 

 of first rank; Brttcke, Ludwig, du Bois-Reymond, Helmholtz. 

 The Faculty desired one of the two last, and as a member of the 

 Senate Bunsen invited Helmholtz to state his present income, 

 and the conditions on which he would consent to be called 

 to Heidelberg. In his reply, dated May 16, 1857, Helmholtz 

 points out that for the time being he is under certain obligations 

 of personal gratitude to the Prussian Ministry for sending him 

 to Bonn on account of his wife's health, and that the situation 

 at Bonn is at present so little developed that its temporary 

 disadvantages would not justify him in disregarding these 

 obligations. Helmholtz also believed that du Bois-Reymond 

 was almost certain to accept the Chair at Heidelberg, which 

 was an additional reason to him for refusing to consider it. 



On June 20, Kirchhoff writes to his old friend Helmholtz, 

 to the effect that he was the only candidate selected by the 

 Faculty, and begging him, if he really declined it, to recommend 

 the appointment of du Bois to the Ministry. On July 14, 

 Helmholtz informs du Bois that after putting the case to the 

 Prussian Ministry, he had been promised an increase of 60 

 salary, with fresh promises of reconstruction of the Anatomy 

 Buildings, so that he had decided definitely to remain at Bonn. 



In July, Helmholtz had the satisfaction of receiving a visit 

 from his father and his sister Julie, after which he went off 

 for several weeks to Switzerland, his farthest point being 

 the Gornergrat. His letters to his wife are as usual filled 

 with beautiful and enthusiastic descriptions, but by the end 

 of August he is back at Bonn, to make the necessary prepara- 

 tions for the Congress of Natural Science to be held there 

 at the end of September, which he describes to his father 

 as follows on October 3 : 



'We were all rather upset till the day before yesterday; 

 People have been here without intermission ever since you 



