HELMHOLTZ IN BERLIN 



theory and developed its applications, more especially 

 in the organic world. He gave a popular exposition 

 of the theory of the transformation of energy into 

 heat, and he even calculated the dynamical equivalent 

 of heat, 1 giving it as 365 kilogramme-meters, instead 

 of the true equivalent, ascertained experimentally by 

 Joule to be 425 kilogramme-meters, for iC. (equivalent 

 to 772 foot-pounds for i F.). His papers produced 

 little effect, even in Germany, at the time of their 

 publication, partly because they were founded so little 

 on experimental enquiry, and partly because they 

 were the work of an obscure physician in a country 

 town. His writings had no influence on science 

 until long after the truth had been proclaimed by 

 Helmholtz. The science of energy would have 

 progressed much as it has done had Mayer never 

 lived ; but, on the other hand, had the doctrine of 

 the conservation of energy come first from Mayer, 

 there would still have been the need of a mathe- 

 matical thinker like Helmholtz to establish it as a 

 law of nature. It is only fair to mention Mayer's 

 obscure position (no fault of his) as an explanation 

 of the fact that, when Helmholtz wrote his essay, 

 he was totally unacquainted with Mayer's work. 

 When, in subsequent years, it was brought under 

 his notice, no one was more generous than 

 Helmholtz in his estimation of the merits of his 



1 Mayer, Liebig's Annalen, vol. xlii., p. 233 ; Phil. Mag., 4th series, 

 vol. xxiv., p. 371 ; Resume'm Phil. Mag., xxv., p. 378. 

 D 



