[ 752 ] 



LXXX. Notices respecting New Boohs. 



Optiqiie qeometrique. By J. Bleix. Pp. vi + 263. Paris: O. Doin 



etEils, 191.2. o fr. 

 Geometrical Optics. By A kchibald Stanley Peecital. Pp. vi-f 



132. Loudon: Longmans, Green & Co., 1913. 



nPHE former of these two books, which forms one of the volumes 

 -*- of the Encyclopedic scientifique, is an excellent summary in 

 very small space of the fundamental principles and methods 

 employed in connexion with this subject. It leads in the end to 

 a consideration of the various methods based upon the charac- 

 teristic function of Hamilton (employed by Maxwell) and upon the 

 several functions derived from it which avoid the difficulties 

 involved in the employment of the characteristic function itself. 

 These have been employed by Lord Bayleigh, Bruns, Schwarzschild, 

 and Pelletan. The account given of Schwarzschild's method is a 

 most luminous one. 



An English reader will probably regret that the author has not 

 included a reference to the paper by Professor Sampson (Royal 

 Society Transactions, 1912) which deals with aberrations of the 

 fifth order and which extends Seidel's five conditions to seven. 



The second of the two volumes is written primarily for medical 

 students. It is rather difficult to guess for whom it is really 

 intended. The preface states that the text embodies all that 

 can reasonably be demanded in any preliminary examination in 

 science. We must assert definitely that scarcely any medical 

 student with whom we have become acquainted (and their total 

 number is very large) would be able to cope with the volume in 

 the very short time which he has at his disposal. 



The book itself has many excellent features when viewed apart 

 from the use to which it is intended to be put. The author has 

 an original way of expressing himself ; many of the old familiar 

 statements appear here in a new dress. The question of cardinal 

 points is dealt with in a very simple manner indeed. If only a 

 large number of senior students can be induced to study the book 

 carefully it will place ophthalmic science in a very different 

 position from that which it is in to-day. 



LXXXI. Proceedings of Learned Societies. 

 GEOLOGICAL SOCIETY. 

 [Continued from p. 660.] 



January 8th, 1913. — Dr. Aubrey Strahan, F.B.S., President, 



in the Chair. 

 rpHE following communications were read : — 



L ' The Geological History of the Malay Peninsula/ By John 

 Brooke Scrivenor, M.A., F.G.S., Geologist to the Government of 

 the Federated Malay States. 



This paper is an attempt to present briefly and in a connected 

 form all the information bearing on the geological history of the 



