Prof. Tyndall on Force. 65 



period at which he wrote, we cannot fail to be struck with astonish- 

 ment at what he has accomplished. Here was a man of genius working 

 in silence, animated solely by a love of his subject, and arriving at 

 the most important results some time in advance of those whose 

 lives were entirely devoted to Natural Philosophy. It was the 

 accident of bleeding a feverish patient at Java in 1840 that led 

 Mayer to speculate on these subjects. He noticed that the venous 

 blood in the tropics was of a much brighter red than in colder lati- 

 tudes ; and his reasoning on this fact led him into the laboratory of 

 natural forces, where he has worked with such signal ability and suc- 

 cess. Well, you will desire to know what has become of this man. 

 His mind gave way ; he became insane, and he was sent to a lunatic 

 asylum. In a biographical dictionary of his country it is stated that 

 he died there : but this is incorrect. He recovered, and, I believe, 

 is at this moment a cultivator of vineyards in Heilbronn. 



While preparing for publication my last course of lectures on 

 Heat, I wished to make myself acquainted with all that Mayer had 

 done in connexion with this subject. I accordingly wrote to two 

 gentlemen who above all others seemed likely to give me the in- 

 formation which I needed. Both of them are Germans, and both 

 particularly distinguished in connexion with the Dynamical Theory 

 of Heat. Each of them kindly furnished me with the list of Mayer's 

 publications ; and one of them 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 Mayer's writings ; but before for- 

 warding the memoirs to me, he read them himself. His letter accom- 

 panying the first of these papers contains the following words : — 

 u 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 sub- 

 jects, in the treatment of which Mayer had anticipated other emi- 

 nent writers. My second 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 beau- 

 tiful essay of Mayer's entitled Beitrdge zur Dynamik des Him-' 

 mels; and in 1854, when Professor 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 referred to 

 by physiologists (by Dr. Carpenter, for example) in terms of ho- 

 nourable recognition. We have hitherto, indeed, obtained fragmen- 

 tary 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 publi- 

 cation. I do not think a greater disservice could be done to a man 



Phil. Mag. S. 4. Vol. 24, No. 158. July 1862. F 



