ON FORCE. 291 
seemed likely to give ' me the information which I 
needed.* Both of them are Germans, and both particu- 
larly distinguished in connection with the Dynamical 
Theory of Heat. Each of them kindly furnished me with 
the list of Mayer's publications, and one of them [Clausins] 
was so friendly as to order them from a bookseller, and to 
send them to me. This friend, in his reply to my first 
letter regarding Mayer, stated his belief that I should not 
find anything very important in Mayers writings; but be- 
fore forwarding the memoirs to me he read them himself. 
His letter accompanying them contains the following words: 
'' I must here retract the statement in my last letter, that 
you would not find much matter of importance in Mayer's 
writings: I am astonished at the multitude of beautiful 
and correct thoughts which they contain; " and he goes on 
to point out various important subjects, in the treatment 
of which Mayer had anticipated other eminent writers. 
My other friend, in whose own publications the name of 
Mayer repeatedly occurs, and whose papers containing 
these references were translated some years ago by myself, 
was, on the 10th of last month, unacquainted with the 
thoughtful and beautiful essay of Mayer's, entitled " Bei- 
trage zur Dynamik des Himrnels," and in 1854, when Pro- 
fessor William Thomson developed in so striking a manner 
the meteoric theory of the sun's heat, he was certainly not 
aware of the existence of that essay, though from a recent 
article in " Macmillan's Magazine " I infer that he is now 
aware of it. Mayer's physiological writings have been re- 
ferred to by physiologists by Dr. Carpenter, for example 
in terms of honoring recognition. We have hitherto, in- 
deed, obtained fragmentary glimpses of the man partly from 
physicists and partly from physiologists; but his total merit 
has never yet been recognized as it assuredly would have 
been had he chosen a happier mode of publication. I do 
not think a greater disservice could be done to a man of 
science, than to overstate his claims: such overstatement is 
sure to recoil to the disadvantage of him in whose interest 
it is made. But when Mayer's opportunities, achievements, 
and fate are taken into account, I do not think that I shall 
be deeply blamed for attempting to place him in that 
honorable position, which I believe to be his due. 
* HeltuLoltz and Clausius. 
