ARMY SURGEON AT POTSDAM 51 



therefore actually produced in the muscle substance, while 

 attempts to demonstrate a rise of temperature in nerve during 

 the transmission of excitation from spinal cord to muscle 

 yielded negative results. These data all made for the verifi- 

 cation of Helmholtz's great law, though the investigations could 

 not then be held conclusive. 



The close of 1847 was devoted to severely theoretical 

 studies, as appears from the many notes on classical pro- 

 blems in pure mathematics found among Helmholtz's papers, 

 but his medical duties hindered him more than was desir- 

 able in the free disposal of his time, until at the begin- 

 ning of 1848 the current of his life was altered by a fortunate 

 development. 



His friend Brucke, who was teacher of anatomy at the 

 Academy of Arts and assistant at the Museum of Anatomy 

 and Zoology, was appointed Professor of Physiology and 

 General Pathology at Konigsberg, and the reversion of the 

 posts thus vacated in Berlin devolved on his intimate friend 

 and contemporary du Bois-Reymond, who was two years older 

 than Helmholtz. But since du Bois' private means made it 

 possible for him to devote himself entirely to his investigations 

 in animal electricity, without taking up professional duties, he 

 retired from the competition for the Academy post in favour of 

 his younger friend, arranging with Brucke that Helmholtz 

 should be brought forward. 



On the strength of an excellent testimonial received from 

 Johannes Miiller, Helmholtz was invited (August 19, 1848) 

 to give a trial lecture before the Senate and Professors of the 

 Academy. This was found among his papers, and has never 

 before been published: 



'I shall endeavour, in the lecture which I have the honour 

 of giving before you, to develop those points which seem to 

 me the most essential in the teaching of anatomy to art- 

 students, and the methods that should be employed. I must 

 from the outset claim the forbearance of this distinguished 

 assembly, since I am well aware what varied capacities and 

 kinds of knowledge should be combined in any one who endea- 

 vours to fulfil the duties of this post successfully, and how 

 difficult is the handling of this science, if it is to be raised from 

 the dry and often barren forms of a colossal effort of memory to 

 a living thing that can be applied to Art. 



E 2 



