LUDWIG AND MODERN PHYSIOLOGY. 373 



entered on his career, lie derived little from his immediate predeces- 

 sors in his own science. He is sometimes placed among the pupils of 

 the great comparative anatomist and physiologist, J. Miiller. This, 

 however, is a manifest mistake, for Ludwig did not visit Berlin until 

 1847, when Miiller was nearly afc the end of his career. At that time 

 he had already published researches of the highest value (those on the 

 mechanism of the circulation and on the physiology of the kidney), 

 and had set forth the line in which he intended to direct his investi- 

 gations. The only earlier physiologist with whose work that of Lud- 

 wig can be said to be in real continuity was E. H. Weber, whom he 

 succeeded at Leipzig, and strikingly resembled in his way of working. 

 For Weber Ludwig expressed his veneration more unreservedly than 

 for any other man excepting, perhaps, Helmholtz, regarding his re- 

 searches as the foundation on which he himself desired to build. Of 

 his colleagues at Marburg he was indebted in the first place to the 

 anatomist, Prof. Ludwig Fick, in whose department he began his career 

 as prosector, and to whom he owed facilities without which he could 

 not have carried out his earlier researches; and in an even higher 

 degree to the great chemist, E. W. Bunsen, from whom he derived that 

 training in the exact sciences which was to be of such inestimable value 

 to him afterwards. 



There is reason, however, to believe that, as so often happens, Lud- 

 wig's scientific progress was much more influenced by his contempo- 

 raries than by his seniors. In 1847, as we learn on the one hand from 

 Du Bois-Reymond, on the other from Ludwig himself, he visited Berlin 

 for the first time. This visit was an important one both for himself 

 and for the future of science, for he there met three men of his own 

 age, Helmholtz, Du Bois-Reymond and Briicke, who were destined to 

 become his life friends, all of whom lived nearly as long as Ludwig 

 himself, and attained to the highest distinction. They all were full of 

 the same enthusiasm. As Ludwig said when speaking of this visit: 

 "We four imagined that we should constitute physiology on a chemico- 

 physical foundation, and give it equal scientific rank with physics, but 

 the task turned out to be much more difficult than we anticipated." 

 These three young men, who were devoted disciples of the great anato- 

 mist, had the advantage over their master in the better insight which 

 their training had given them into the fundamental principles of scien- 

 tific research. They had already gathered around themselves a so-called 

 "physical" school of physiology, and welcomed Ludwig on his arrival 

 from Marburg, as one who had of his own initiative undertaken in his 

 own university das Befreiungswerk aus dem Mtalismus. 



The determination to refer all vital phenomena to their physical or 

 chemical counterparts or analogues, which, as I have said, was the 

 dominant motive in Ludwig's character, was combined with another 

 quality of mind, which, if not equally influential, was even more obvi- 

 ously displayed in his mode of thinking and working. His first aim, 



