422 HERMANN VON HELMHOLTZ 



and after a shorter break. So that from my own experience 

 I recommend you to live entirely for your health for some time 

 to come. The weakness that remained from my great loss of 

 blood in October has almost entirely disappeared, and the 

 strained eye-muscles have made good progress in accustoming 

 themselves to new orientation of the visual images. It is only 

 in rapid turns and motions of the body that I still occasionally 

 feel a vertigo.' 



Helmholtz had scarcely returned to Berlin when he received 

 the news of the death of Kundt. He had esteemed him highly 

 as a scholar and a man, and would not be dissuaded at the 

 funeral on May 21, 1894, from expressing his feelings of deep 

 regret at his decease. The emotion under which he was 

 labouring is unmistakable in the notes for this funeral oration, 

 which were found among his papers : the heavy blows which 

 fate had dealt him of late years the death of his beloved son 

 Robert, the constant illness in mind and body of his son 

 Fritz, his own deplorable accident on the ship, the death of his 

 great pupil Hertz, so swiftly followed by the loss of the friend 

 and colleague, taken in the midst of his mental and bodily 

 vigour were almost more than he could bear. 



On April 28, Lenard approached Helmholtz with a request as 

 follows : 



* My request concerns Hertz's Principles of Mechanics, the 

 publication of which he confided to me. As you know, Hertz 

 had brought the book so nearly to a conclusion in his last days 

 that he was himself able to give the larger portion of it to the 

 publisher. But he sent the MS. off regretfully, since he would 

 have liked to hold the book back for six months longer, in 

 order to work through the Second Part of it again. The desire 

 to omit nothing, and to do the best that is possible for the book, 

 decided me to apply to you when the time came, with the 

 request that you would be so good as to look through the two 

 passages indicated, and to advise me in regard to them. I should 

 only consider myself justified in making any important alteration 

 if you were to advise it. . . .' 



Helmholtz replied on May 21 : 



' Forgive me for not having answered your questions sooner. 

 But since I returned from my journey I have had little spare 

 time for the tranquil consideration and thorough understanding 



