AT THE PHYSICO-TECHNICAL INSTITUTE 399 



sometimes been able to do this for you. On the other hand 

 I have received much from you in return, especially while 

 I was engaged in physiology, where you were always my chief 

 authority. For the last fortnight I have been sitting three 

 hours daily as a model to the sculptor Hildebrand, who is 

 reproducing me in marble. My health has been very good 

 so far, and I am prepared for the Berlin Commemoration. 

 Naturally the thought of one's seventieth birthday is a mixed 

 joy, and hardly a festival ; but I must confess that the amount 

 of tokens of sympathy, and of respect and gratitude, which 

 have poured in on all sides, and the greater part of which 

 must be meant in a right spirit, since they were quite un- 

 solicited, has something solemn and elevating. Apart from 

 all questions of vanity, it is legitimate for one of us, who has 

 worked hard all his life, to ask, ' Is what you have done useful 

 and worth having ? ' and this can only be answered by others, 

 who have found it useful and profitable. . . .' 



On the Emperor Frederick's birthday he was made Wirk- 

 licher Geheimrath, with the title of ' Excellency ', by patent 

 granted on October 12, 1891, by the Emperor William II in 

 Potsdam. 



November 2 was the date of the ovation to Helmholtz in 

 Berlin, which was a memorial not only to him, but to the in- 

 vestigators of every country, in its ungrudging recognition of 

 his immense services to science, and of his fine and noble 

 personality. It will suffice to quote the words of du Bois- 

 Reymond, from the legion of testimonies borne by Ministers, 

 Academies, Scientific Corporations, and individual Students: 



1 We issued an appeal, as international as is science, reaching 

 beyond all bounds of Chauvinism and of politics, to the learned 

 men of whatever category, to physicists, mathematicians, phy- 

 sicians, physiologists, all of whom must perforce acknowledge 

 themselves as your admirers, and your pupils : and the result 

 of this appeal is shown in the list I herewith hand you, con- 

 taining some 700 names (I have not counted them exactly), 

 among which, however, are Societies which in themselves 

 include a vast number of signatures. The appeal has been so 

 successful that it has provided us with ample funds for realizing 

 several tokens of our homage. Yonder bust is known to 

 you already, since you sat for it. We return our thanks to the 



