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upon him an attraction greater than that of pure geometry or algebra. 

 By the time that the lad was of age to go to the University his 

 interest in physics had developed iuto " an absorbing impulse, 

 amounting even to a passion." 



As, however, a livelihood could not be gained from a knowledge 

 of that branch of science, his father advised him to undertake the 

 study of medicine, a sensible proposal, to which the younger man 

 assented without much difficulty. He therefore entered the Friedrich- 

 Wilhelm Institute, a military medical school, in which the poorer 

 students were materially aided while preparing for their future pro- 

 fession. He was thus led to take an interest in physiology, and was 

 fortunate in that he came under the immediate influence of Johannes 

 Miiller. Among his fellow students were E. du Bois-Reymond, 

 E. Briicke, C. Ludwig, and Yirchow. 



His career as a student and teacher, brilliant as it was, may be dis- 

 missed in a few words. 



In 1848 he was permitted to withdraw from the Army Medical 

 Service, and was appointed Teacher of Anatomy in the Academy of 

 Arts, in Berlin. Only another year elapsed before he received the 

 more important appointment of Professor of Pathology and Physi- 

 ology in Konigsberg. This was followed by the Professorship of 

 Anatomy in Bonn (1855), of Physiology in Heidelberg (1858), and 

 of Physics in Berlin (1871). During the last years of his life he 

 held one of the highest posts to which any scientific man in Germany 

 can aspire. He was Director of the new " Physikalisch-Technische 

 Reichsanstalt " at Berlin. 



Amid this unruffled professional success, Helmholtz published a 

 long series of papers and books. It has been said that as each of 

 seven cities contended for Homer, so seven sciences, mathematics, 

 physics, chemistry, physiology, medicine, philosophy, and aesthetics 

 claimed Helmholtz for their own,* and it is interesting to note how 

 early he took the comprehensive view of science which justifies this 

 rhetorical statement. 



His first paper (apart from an inaugural dissertation) showed a 

 clear appreciation of the necessity of distinguishing vital from non- 

 vital phenomena. In this memoir, published in 1843, he proved the 

 two negative propositions, that fermentation and decay are not merely 

 chemical processes due to the oxygen of the air, and that they are 

 not propagated by dissolved substances which can diffuse through a 

 porous membrane. He concluded that they resembled vital phenomena 

 " by the similarity of the materials in which they occur, by the mode 

 in which they spread, and by the similarity of conditions which are 

 essential for their preservation or for their destruction." It is evi- 



* ' Gedachtnissrede auf Hermann von Helmholtz.' T. W. Engelmann. Leipzig, 

 1894. 



