1895.] on the Physical Work of von llelmholtz. 483 



and his views.* Helmholtz was not, and did not claim to be an 

 original author of the doctrine of the conservation of energy ; but two 

 young men, Sir William Thomson in llngland, and Helmholtz in 

 Germany, independently, and within a month of each other, were 

 the first persons who compelled the scientific world to regard it 

 seriously. 



There is one interesting fact which connects this essay directly 

 with the Royal Institution. Four years after it was published, it was 

 placed by Du Bois Reymond in the hands of one who was lost to 

 science in the same year as von Helmholtz himself — the late Prof. 

 Tyndall. He was much impressed, and has spoken of the incident 

 as bringing him face to face with the great doctrine of the " Conser- 

 vation of Energy." f He translated the essay into English, and for 

 many years made it his habit to place every physical paper published 

 by Helmholtz within the reach of English readers. 



And now, having brought you to the point at which Helmholtz 

 may be said to have been fairly started on his life's work, let me first 

 describe briefly his official career, before I consider his achievements 

 in greater detail. 



When his extraordinary abilities became evident, he was permitted 

 to sever his connection with the army. At twenty-seven years of age 

 he became Teacher of Anatomy in the Academy of Arts at Berlin. 

 In the next year he was appointed Professor of Anatomy and Physio- 

 logy at Konigsberg, and he held similar posts in the Universities of 

 Bonn (1855-58) and Heidelberg (1858-71). It was not till 1871 

 that his early love for physics was finally rewarded. When the chair 

 of Physics was to be filled in the University of the newly-founded 

 German Empire, in Berlin, it was felt that even in Germany — the 

 land of specialists — no better occupant could be found than one who 

 was then in his fiftieth year, and who had been all his life a teacher 

 of anatomy and physiology. The choice was universally approved 

 and completely justified, and von Helmholtz held this post till his 

 death. 



In this connection I am, by the kindness of Sir Henry Roscoe, 

 enabled to show to you a relic of remarkable interest. It is a 

 photograph of the great teacher and investigator, taken at the very 

 last lecture that he delivered — that, namely, on July 7, 1894. 



For some years, that is, from the date of its foundation, von 

 Helmholtz was the president of the Physikalisch-Technische Reichs- 

 Anstalt in Charlottenburg. This institution, founded partly by the 

 munificence of the late Dr. Werner Siemens, partly by funds supplied 

 by the State, has no precise analogue in this country. It is devoted 

 to the carrying out of systematic researches on questions of funda- 

 mental importance to which a long time must be devoted. 



* Fortnightly Review, November, 1894. 



t * Introduction to Popular Lectures by Helmholtz,' translated by E. Atkin- 

 son, 1873. 



