ON THE PHYSICAL VIEW. OF NATURE. 



149 



duced in Germany, and that especially the ideas of 

 Faraday and Maxwell were popularised, expounded, and 

 submitted to elaborate tests. These culminated in the 

 brilliant discoveries of Hertz already referred to. 



As in his earlier researches into the connection of the 

 phenomena of heat and mechanical work, so in these 

 later ones concerning 1 the electro-dynamic laws, Helm- 34. 



J Helmholtz 



holtz seems to have approached his subject primarily in *lf' 

 the interest of physiological l science. At that time 



the British Association and the still 

 older "Lectures" of the Royal 

 Institution. Before his time there 

 were only rare instances notably 

 those of Bessel, Liebig, and Hum- 

 boldt where scientific thinkers of 

 the first rank condescended to influ- 

 ence general opinion and polite 

 literature by stepping down from 

 the university chair into the arena 

 of a popular audience. No other 

 German scientific thinker has left 

 a collection equal to Helmholtz's 

 ' Vortrage und Reden, ' not even 

 Bessel, whose ' Populare Vorlesun- 

 gen iiber wissenschaftliche Gegen- 

 stande ' (ed. Schumacher, Hamburg, 

 1848) are too little known. Du 

 Bois-Reymond's ' Reden ' are a mine 

 of information on the history of 

 science, and von Baer's ' Reden ' 

 (Braunschweig, 1886) contain some 

 excellent and original discourses. 



1 Emil du Bois - Reymond, in 

 many passages of his remarkable 

 addresses, and latterly in his ap- 

 preciative Eloge of Helmholtz 

 (Leipzig, 1897), has preserved the 

 historical data for a genetic history 

 of Helmholtz's electrical researches, 

 which, beginning in 1851, and cul- 

 minating in Hertz's brilliant ex- 

 periments on the "rays of electric 

 energy " in 1888, completely 

 changed the aspect of electrical 

 science in Germany and to a less 

 degree in France. The older view, 



based upon a mathematical develop- 

 ment of the fundamental concep- 

 tion of Ampere and mainly asso- 

 ciated with the brilliant name of 

 Wilhelm Weber, whose very ex- 

 tensive and accurate measure- 

 ments largely supplied the material 

 for the modern theory, is prac- 

 tically unknown to electricians in 

 this country. No English text-book 

 contains even a reference to a view 

 which was once dominant abroad, 

 and which for this reason forms 

 a very interesting episode in the 

 history of thought. In the fourth 

 chapter I have referred to this 

 view as, beside the theory of Bos- 

 covich, presenting one of the most 

 remarkable applications of the as- 

 tronomical view of nature, which 

 originated in this country but was 

 mainly cultivated by the French 

 school. I must now briefly refer 

 to the counter-movement, which 

 in Germany is mainly identified 

 with the name of Helmholtz. He 

 may be said to have left the mark 

 of his genius on the scientific 

 history of his country as Lord 

 Kelvin has done on that of Eng- 

 land. His collected papers show us 

 and du Bois-Reymond tells us 

 how Helmholtz's interest in elect- 

 rical problems was connected with 

 the remarkable phenomena of ani- 

 mal electricity, to the exploration 

 of which the former devoted his 



