PROFESSOR AT HEIDELBERG 251 



their hands against myself. And as I cannot succeed in de- 

 ciphering the greater part of the tricks exhibited before me by 

 a skilful conjurer, I certainly could not undertake to interpret 

 all the magnetic or spiritualistic or hypnotic wonders that any 

 one may show me ; the less so as the social position or sex of 

 the confederates generally prohibits a really searching investiga- 

 tion ; often enough too they will urge the ingenious excuse that 

 the presence of an obstinate unbeliever has broken the spell. 



' As far as I am personally concerned, it has always been the 

 psychological phenomenon of credulity that has interested me 

 in these matters, and I have therefore successfully adopted the 

 role of impostor from time to time in table-turning or thought- 

 reading, of course explaining afterwards that I had been the 

 sinner. 



' If after these explanations you are still interested in my 

 private opinion, I can only say that I entirely agree with my 

 friend and colleague Herr E. du Bois-Reymond. For the rest 

 I do not deny that there is a core of truth in the phenomena of 

 hypnotism. But what there is of truth in it will hardly appear 

 so very wonderful. 



' As to the employment of such mystical influences in poetry, 

 I can only speak as spectator and reader. As such, I find that 

 I can only comprehend and sympathize with accountable beings. 

 Charms are not repugnant to me, so long as they only constitute 

 an abbreviation of some natural psychical process, which would 

 actually require more time and more intermediate stages. 

 Where that is not the case, my sympathy with the processes 

 immediately vanishes, the theoretical explanation of this being 

 quite obvious/ 



Helmholtz's scientific interests and discoveries were steadily 

 turning away from physiology to an almost exclusive devotion 

 to physics and mathematics, and, as was only natural, he began 

 to wish that he could also concentrate his teaching more 

 entirely in this direction. 



In the summer of 1868, while his wife was on the Baltic coast 

 for the sake of their son Robert's health, and Helmholtz, already 

 fully occupied with lectures, laboratory and other scientific work, 

 was also teaching plane trigonometry to his son Richard in his 

 leisure hours, to prepare him for the Polytechnic at Stuttgart, 

 he received proposals from Bonn to undertake the Professor- 



