222 Prof. Tyndall on the Claims of Mayer and Joule. 



duce this impression. If not, they will perhaps have the kindness 

 to say so in the proper place. If they did, then I trust they will 

 not deem me unreasonable if I ask them to be more explicit. I 

 hereby openly invite them to point out the particulars in which 

 I have .erred in judgment or misrepresented facts. I challenge 

 them to do so, not in the spirit of polemical bravado, but because 

 I know my own readiness to make prompt atonement for any 

 wrong that I may have done. I can scarcely allow myself to 

 suppose that the charge implied in the phrase " depreciate or 

 suppress the claims of our own countrymen/' is meant to apply 

 to me. But it is at least doubtfully employed, placed as it is in 

 such close proximity to a most pointed reference to myself. The 

 grammatical meaning of the sentence which follows seems to be 

 that " attempts (made by others) to place Mayer in a position 

 which he never claimed/' were " supported " by me. As a 

 matter of fact, this is incorrect. 



The assertion of Messrs. Thomson and Tait, that Mayer had 

 never claimed the position which I assigned to him, is also 

 incorrect. It is true, indeed, that the " claims " of Mayer have 

 been few and far between ; and in this respect his example 

 might, in many cases, be followed with advantage. He recog- 

 nizes the great merits of Mr. Joule ; he says it cannot be denied 

 that he made the independent discovery of the convertibility 

 and equivalence of heat and motion. He dwells with pleasure 

 upon Joule's beautiful researches, and states that the law of 

 equivalence, and its numerical expression, were published almost 

 simultaneously in Germany and in England. As far as I can 

 judge, he desires nothing more than permission to stand beside 

 his more fortunate fellow-labourer in the memory of men. But 

 he will not bear, nor do I think the scientific world will call upon 

 him to bear, removal from the position which he has so fairly- 

 won. At page 53 of his last pamphlet, entitled Bemerkungen 

 uber das mechanische Equivalent der W'drme (Hielbronn, 1851), 

 he writes thus: — "The new subject (the mechanical theory of 

 heat) soon began to excite the attention of learned men ; but inas- 

 much as both at home and abroad the subject has been exclu- 

 sively treated as a foreign discovery, I find myself compelled to 

 make the claims to which priority entitles me; for, although 

 the few investigations which I have given to the public, and 

 which have almost disappeared in the flood of communications 

 which every day sends forth, without leaving a trace behind, 

 prove, by the very form of their publication, that I am not one 

 who hankers after effect, it is not therefore to be assumed that 

 I am willing to be deprived of intellectual property, which docu- 

 mentary evidence proves to be mine." 



In my morning lectures, which extended over three months of 



