HERMANN VON HELMHOLTZ 



of Weber's statement of electrical action at a distance, 

 and by his papers on hydrodynamics ; (2) later works, 

 such as those on electrolysis and on the more hidden 

 movements implied in his theory of cyclic systems, 

 show Helmholtz taking advantage of molecular hy- 

 potheses. In his appreciation of Helmholtz's labours, 

 Wiedemann gives this little personal touch to the 

 picture that seems to bring the man before us : c Helm- 

 holtz did with nature just what he did in looking at a 

 picture or listening to a piece of music. He looked 

 for a scientific foundation and analysed his feelings. 

 The waves of the sea breaking on Cape d'Antibes 

 roused his scientific spirit. From the relative velocity 

 of the wind and the number of waves on the surface 

 of the sea, he drew conclusions as to the arrangement 

 of the clouds, and these were submitted to mathe- 

 matical investigation. 1 



An exhaustive account of the physical researches of 

 Helmholtz would far exceed the limits of this work ; 

 and indeed it is almost impossible to give the results 

 in untechnical phraseology without running the risk 

 of being much misunderstood, and yet no true notion 

 can be formed of this great Master in Medicine without 

 recognising that it was in physical research, both in 

 the animate and inanimate world, that he truly ex- 

 celled. In this department the labours of his life may 

 be summed up under six heads: (i) On the Con- 

 servation of Energy ; (2) On Hydrodynamics ; (3) On 



1 Wiedemann, op. cit. xzxi. 

 I 9 2 



