XXX INTEODUCTION. 



prime applications in advance of any other thinker, but he has 

 done his work under circumstances and in a manner which awa- 

 kens the highest admiration for his genius.* 



An eminent authority has remarked * that these discoveries open 

 a region which promises possessions richer than any hitherto 

 granted to the intellect of man.' Involving as they do a revolution 

 of fundamental ideas, their consequences must be as comprehen- 

 sive as the range of human thought. A principle has been devel- 

 oped of all-pervading application, which brings the diverse and 

 distant branches of knowledge into more intimate and harmonious 

 alliance, and affords a profounder insight into the universal order. 

 Not only is science itself deeply affected by the presentation of its 

 questions, in new and suggestive lights, but its method is at once 

 made universal. There is a crude notion in many minds, that it j 8 

 the business of science to occupy itself merely with the study of 

 matter. "When, hitherto, it has pressed its inquiries into the higher 



* Prof. Tyndall remarks : " Mayer probably had not the means of making experi- 

 ments himself, but he ransacked the records of experimental science for his data, and 

 5^ *> thus conferred upon his writings a strength which mere speculation can never possess^. 

 From the extracts which I have given, the reader may infer his strong desire for quan- 

 t V titative accuracy, the clearness of his insight, and the firmness of his grasp. Kegard- 

 ^ \J^ ing the recognition which will be ultimately accorded to Dr. Mayer, a shade of trouble 

 doubt has never crossed my mind. Individuals may seek to pull him down, but 

 -^ "their efforts will be unavailing as long as such evidence of his genius exists, and as 

 long as the general mind of humanity is influenced by considerations of justice and 

 truth. 



vy " Th e paucity of facts in Mayer's time has been urged as if it were a reproach to 



him ; but it ought to be remembered that the quantity of fact necessary to a generaliza- 

 ' ^__, tion is different for different minds. 'A word to the wise is sufficient for them, 1 and 

 a single fact in some minds bears fruit that a hundred cannot produce, in others. 

 .Mayer's data were comparatively scanty, but his genius went far to supply the lack of 

 experiment, by enabling him to see clearly the bearing of such facts as he possessed. 

 They enabled him to think out the law of conservation, and his conclusions received 

 the stamp of certainty from the subsequent experimental labors of Mr. Joule. In ref- 

 erence to their comparative merits, I would say that as Seer and Generalizer, Mayer, 

 in my opinion, stands first-^ts experimental philosopher, Joule.' 1 '' 



