338 GREAT MEN OF SCIENCE 



whole personality was reflected, and at the same time in their 

 natural simplicity, combined with perfection of form; the 

 joy of the discoverer was communicated to the hearer in all 

 his demonstrations and explanations.^ He was a shining 

 example of the cultivation of pure science; the idea of gain- 

 ing personal advantage from his inventions, which would 

 have been easy in the case of the burner, the photometer, and 

 many others, was entirely strange to him. His life lay 

 almost entirely in the laboratory among his pupils, who were 

 also able to be witnesses of his own researches, as they were 

 being carried on. His remarks were often full of humour 

 under the mask of the greatest seriousness; his mode of 

 thought produced its impression without making any direct 

 claim to superiority. He did not found a family; in the uni- 

 versity vacations he loved to make long journeys, generally to 

 the south, often accompanied by friends among his colleagues. 



At the age of seventy-eight Bunsen retired from teaching; 

 for a further ten years he enjoyed walks, and later drives, in 

 the woods around his beloved town, from which no offers, 

 however attractive, had ever been able to separate him. 



Gustav Kirchhoff was born at Konigsberg in Prussia as 

 the third son of a legal dignitary, and also studied there. He 

 entered the University of Berlin in the year 1848, and then 

 became an assistant professor in Breslau. There he first 

 met Bunsen, who in 1854 obtained an invitation to Heidel- 

 berg for him. In the year 1875 Kirchhoff left this scene of 

 his most successful activity, where he had also married a 

 second time after the early death of his wife, and went to 

 Berlin, to work alongside Helmholtz. An injury to his foot 

 caused by a fall on a staircase, had been cured, but in- 

 creasing infirmity appeared, and he died twelve years later at 

 the age of sixty-three. 



1 Wider circles also knew of them; princes and men eminent in intel- 

 lectual life who travelled through Heidelberg were not seldom seen in his 

 lecture theatre - which lay at the corner of Academiestrasse and Plock - 

 among his own students. 



