CARL LUDWIG. 161 



as he chose to issue over the simple signature of C. Ludwig 

 have become classical. His life-work finds expression in 

 the lone series of scientific memoirs, which contain the 

 result of his investigations for the most part undertaken 

 along with his pupils, while the memoir itself usually bore 

 only the pupil's name. He published the second edition of 

 his Lehrbuch der Physiologie in 1858-61, dedicating it to 

 his three friends, Du Bois-Reymond, Helmholtz and 

 Brticke. The book opens with the striking words, not so 

 striking now perhaps as they were then, when physiology 

 was largely dominated by the so-called vitalistic doctrines 

 of Johannes Midler : " Die wissenschaftliche Physiologie 

 hat die Aufo-abe, die Leistunoen des Thierleibes festzus- 

 tellen und sie aus elementaren Bedingungen desselben mit 

 Nothwendigkeit herzuleiten," and his aim was to show 

 that " alle vom thierischen Korper ausgehenden Leistungen 

 eine Folge der einfachen Anziehungen und Abstossungen 

 sind ". In other words, he sought to bring the phenomena 

 manifested by living beings into line with those of physical 

 science, and to apply to their elucidation the same methods 

 as are applicable to the study of physical and chemical 

 phenomena. To study or even to regard biological 

 phenomena from a physical and chemical standpoint was 

 at that time still a new conception, yet this idea, as v. 

 Kries well expresses it, formed the " Grundton " of Lud- 

 wig's whole scientific bias. Indeed, his first scientific 

 work on the secretion of urine was carried out on these 

 lines, and to the end he remained true to this principle. 

 But Ludwig was well aware that there are many phenomena 

 manifested by living organisms for which there are no 

 directly analogous phenomena in inorganic nature ; but the 

 point is, that his endeavour throughout was by anatomical, 

 physical and chemical investigations to arrive at such a 

 knowledge of the organ to be investigated as to secure a 

 basis on which the interpretation of the phenomena mani- 

 fested by it might become explicable by facts already 

 known. One of the necessities of his whole conception of 

 any physiological process was to obtain a comprehensive 

 and palpable representation of the relation between an 



