Notices respecting New Books. 153 



The increase of the magnetic resistance with the length of 

 the bar is without doubt to be ascribed to the intrinsic mag- 

 netic resistance of the steel. 



The discovery of the precise laws of magnetic resistance in« 

 such cases must form the subject of further experiment. 



The bars B and C so slightly affect an external needle that 

 the demagnetization-experiment cannot be made on them with 

 any accuracy. It is not in any case an experiment of a very 

 accurate character, and perhaps too much stress may be laid 

 on the want of exact accordance between its results and 

 others. 



XIX. Notices respecting New Books. 



The Scientific Papers of James Peescott Joule. Published by the 

 Physical Society. Vol. I. London : Taylor and Francis. 1884. 



T\7E have the authority of the Prime Minister for the statement 

 * * that the present age is not one abounding in minds of the 

 first order. Perhaps not, from the popular (i. e. the superficial) 

 point of view. But that it can hold its own, in this respect, with 

 any previous age, will undoubtedly be the verdict of posterity. 

 For the true and only test of a " mind of the first order " is to be 

 sought in the creations of that mind, and their influence for good 

 upon the intellectual and moral progress of our race. It may be 

 that there is a dearth of popular idols — literary, artistic, political, 

 philosophic, &c. "What of that ? Alike in the study of the mathe- 

 matician and in the laboratories of the chemist, the physicist, and 

 the physiologist, are now being developed ideas, results, and pro- 

 cesses which will have an influence on the future, in comparison 

 with which the utmost efforts of statecraft are but as a drop in the 

 bucket. "Watt and Faraday, Wohler and Liebig, Lister and 

 Pasteur, Helmholtz and Thomson : — what achievement of states- 

 man or warrior in any age can be compared, either in intellectual 

 grandeur or in true usefulness, with theirs ? 



" Begum timendorum in proprios greges, 

 Beges in ipsos imperium est Jovis." 



The quiet, all but unknown, student is in these latter days the real 

 master of monarchs and of civilization. But such a theme as this 

 is unsuited to a scientific journal, and must be left to the next 

 Votes sacer, if such a phenomenon be any longer possible. 



The volume before us is the work of a mind undoubtedly " of 

 the first order." As usually happens to a great discoverer, Joule's 

 earlier efforts were received with coldness, even suspicion; then 

 (as Whewell remarked of Forbes and his Grlacier-Theory) they 

 passed to the second stage, in which they were acknowledged to be 

 true, but not new. This stage, also, was of short duration, and 

 Joule's transcendent merits are now all but universally recognized. 



