430 HERMANN VON HELMHOLTZ 



State, von Rottenburg, had called on his birthday, and declared 

 that the Emperor would never consent to his resignation. 



On the following day new symptoms of paralysis set in ; a 

 succession of weary days and nights began, in which his vital 

 forces were gradually exhausted, till after the unspeakable 

 sufferings of the last day the end came on September 8, at 

 eleven minutes past one in the afternoon. 



' His early death, which removed him in the midst of his full 

 working powers,' said du Bois Reymond, ' was felt not merely 

 as an irreparable loss to Science, but as a national misfortune/ 



The scientific men of Europe had been looking forward to the 

 end of September with keen anticipation, since it was known that 

 Helmholtz had consented to give a lecture to the Naturforscher- 

 Versammlung in Vienna, 'On Persistent Forms of Motion 

 and Apparent Substances/ In a letter addressed to Siegmund 

 Exner, the President of the Congress, Helmholtz had declared 

 his willingness to address the Meeting, but added that it would 

 not be easy at his advanced age to pledge himself definitively, 

 ' so I end with the well-known riddle : 



Das erste ist nicht wenig, 

 Das zweite ist nicht schwer, 

 Das Ganze macht Dir HofFnung, 

 Doch trau' ihm nicht zu sehr/ 



Some brief notes headed 'Naturforscher-Rede* may be given 

 here, as they are in close relation to the subject which Helmholtz 

 had chosen as the theme of his lecture : 



' . . . I hold that the fittest theme for any speaker who has 

 undertaken to address one of the General Meetings of the As- 

 sociation is to call attention from time to time to the changes 

 that have taken place in the general aspects of Science. 

 In sciences which have already attained a high degree of 

 elaboration, these alterations can only take place slowly, and in 

 little isolated steps. It is after comparatively long periods that 

 they first become plainly perceptible, and then only to those 

 who can look back over the experiences of a long life, passed in 

 the midst of scientific work and the frequent reflections and 

 doubts attaching to it, or to those who have acquired a corre- 

 sponding knowledge of the historical development of Science 

 by special historical studies. 



