404 FRAGMENTS OF SCIENCE 



which I may have fallen regarding their author. "Bemer- 

 kungen liber die Krafte der unbelebten Natur," Liebig's 

 "Annalen," 1842, vol. 42, p. 231; "Die Organische Be- 

 wegung in ihrem Zusammenhange mit dem Stoffwechsel, " 

 Heilbronn, 1845; "Beitrage zur Dynamik des Himmels, " 

 Heilbronn, 1848; "Bemerkungen iiber das Mechanische 

 Equivalent der Warme," Heilbronn, 1851. 



IN MEMOEIAM. Dr. Julius Eobert Mayer died at Heil- 

 bronn on March 20, 1878, aged 63 years. It gives me 

 pleasure to reflect that the great position which he will 

 forever occupy in the annals of science was first virtually 

 assigned to him. in the foregoing discourse. He was sub- 

 sequently chosen by acclamation a member of the French 

 Academy of Sciences; and he received from the Eoyal 

 Society the Copley medal its highest reward. 1 



NOVEMBER, 1878. 



At the meeting of the British Association at Glasgow 

 in 1876 that is to say, more than fourteen years after its 

 delivery and publication the foregoing lecture was made 

 the cloak for an unseemly personal attack by Professor 

 Tait. The anger which found this uncourteous vent dates 

 from 1863, a when it fell to my lot to maintain, in opposi- 

 tion to him and a more eminent colleague, the position 

 which in 1862 I had assigned to Dr. Mayer. In those 

 days Professor Tait denied to Mayer all originality, and 

 he has since, 1 regret to say, never missed an opportunity, 



1 See "The Copley Medalist for 1871," p. 479. 



2 See "Philosophical Magazine*"* for this and the succeeding years. 



