Notices respecting New Books. 135 



just mentioned, however, it is evident that such a discharge is 

 not requisite, any more than a violent motion of the liquid. 



That view would also be untenable for this reason, because 

 we have here to do with elliptically polarized, and not with 

 depolarized light. 



If it is further shown that explanations which rest upon the 

 hypothesis that electricity may produce these phenomena indi- 

 rectly, are not confirmed by an experimental investigation, it 

 becomes more and more probable that we have to do here with 

 a hitherto unknown action of electricity on the light-undula- 

 tions; and then Kerr's phenomena, as Hontgen justly says, 

 acquire an extraordinarily fundamental significance. 



I hope soon to touch this subject again. 



Harlem, March 1882. 



XYI. Notices respecting New Books. 



(i) Mathematical Papers by William Klxgdox Cllttoed. Edited 

 by Kobeet Titck.ee, with an Introduction by H. J. Stephen 

 Smith. London: jNIacruillan and Co. 1882. (8vo, pp. lxx, 658.) 



(ii) Mathematical Fragments, being Facsimiles of his unfinished 

 Papers relating to the Theory of Graphs, by the late W. K. Cllttoed. 

 London : Macmillan and Co. (Pol., pp. 22.) 

 rpO those who remember the late W. K. Clifford's appearance as 

 -*■ a rising mathematician of singularly brilliant promise, one 

 likely to extend the limits of knowledge in any of the various 

 fields of Mathematics to which he might be led to apply his powers, 

 his short career of little more than a decade would seem a mere 

 dream, but for the substantial evidence of his energy and pro- 

 ductiveness contained in the thick volume of more than six 

 hundred octavo pages (one third consisting of matter in close type) 

 which we have here to notice. And it is to be borne in mind that 

 the publication of this volume has been preceded by the collection 

 of two volumes of Lectures and Essays produced subsequently to 

 Clifford's removal from Cambridge to London in 1871. The former 

 publication (of more popular matter, but handled invariably with 

 characteristic scientific precision and freshness), together with 

 the collection which forms the subject of the present notice, may 

 interest (and they are deeply interesting) from either of two points 

 of view, — one of* which has occupied the pen of Prof. H. J. S. 

 Smith in a masterly Introduction ; and the other will be more par- 

 ticularly here dwelt on — the study of the growth of a singularly 

 gifted genius as it derived fresh aliment from extended acquaint- 

 ance with the work and speculations of kindred minds, and visibly 

 waxed stronger and stronger in its own powers by their exercise on 

 problems of ever increasing height and subtlety. 



