ON THK PHYSICAL VIKW OF NATIIIK 



10' 



foremost place to the short memoir of F. ^lohr entitled n. 

 "On the Nature of Heat," which appeared in 1<S:;7 in 

 an obscure scientific periodical published at ^'ienna. The 

 publication of it remained unknown, even to the author 

 himself, and was certainly unappreciated by the scientific 

 world for more than thirty years.^ 



' The story of Mohr's memoir is 

 curious, not to say romantic. His 

 original paper, ' Ueber die Natur 

 <ler Wiirme,' was offered to Pog- 

 gendorf and refused, as were the 

 later memoii'.s of Mayer and Hehn- 

 holtz. A dread of inlroducing 

 speculative matter into the ' An- 

 naleu ' prevented likewi.-^e — as I 

 related above (p. 66, note 2) — the 

 appreciation of much of Faraday's 

 later work. He then sent the ^lS. 

 to Baumgartner, in Vienna, who — 

 always interested in theoretical 

 jihysics — printed it in a periodical 

 (' Zeitschrift fiir Physik ') of which 

 he and von Holger were joint- 

 editors. He did not inform the 

 autliur of this. Mohr was a re- 

 markably original thinker, in whose 

 mind important ideas rose at times 

 to extraordinary clearness, but who, 

 like many original thinkers, did not 

 always appreciate his own itleas at 

 their true value, and accordingly 

 treated them with neglect, and did 

 not consistently develop them. In 

 the present instance he contented 

 himself with inserting an abstract 

 in the ' Annalen der Piiarmacie ' 

 (vol. xxiv. p. 141), of which he was 

 then joint - editor, together with 

 Liebig and Merck. He made no 

 further inquiries as to the fate of 

 his larger memoir, and, in con- 

 versation with friends up to the 

 j'ear 1860, as also in his 'Mechan- 

 ische Theorie der chemischen 

 Aftinitat' (Braunschweig, 1868, p. 

 4l>), used to deplore the loss of a 

 document which, more fully than 

 the short paf>er in the 'Annalen der 



Pharmacie,' would have establislied 

 his priority in the clear enunciation 

 of a remarkable principle wliich 

 fifteen years later received general 

 recognition. The matter would 

 probably have rested there had it 

 not been that Tyudall, in the year 

 1862, in a celebrated lecture before 

 the Royal Institution, commenced 

 that long series of historical and 

 controversial jtublications in which 

 many persons, includhig himself, 

 Joule, Tait, d tiding, Helmholtz, 

 Akin, Bohn, Diihring, Zollner, 

 and others took part, and in 

 which, among several claims prior 

 to or contemporary with Mayer's, 

 those also of Mohr received due 

 recognition. It seems to have 

 been especially l)r Akin who drew 

 attention to Mohr's claims, and 

 searched in the forgotten volumes 

 of the Austrian periodical for the 

 original memoir, which, unknown to 

 the author himself, had been in- 

 scribed on p. 419 of the fifth volume. 

 This discovery he announced to 

 Mohr himself after having already, 

 in November 1864 ('Phil. MagV 

 4th series, vol. xxviii. p. 474 \ 

 given several extracts, among which 

 is the one quoted by me in tlie 

 text. Mohr published, in 1869, a 

 sequel to the above-mentioned book, 

 entitled ' Allgemeine Theorie der 

 Bewegung und Kraft,' in which lie 

 refers to Dr Akins discovery, and 

 reprints the original menu>ir in 

 full. Since that time his name has 

 figured in many historical uccount.s 

 as one of tlie pioneers in the de- 

 velopment of the energy - coucep- 



