82 Scientific Intelligence. 



of an apparent parados which occurs in the discussion of Barlow's 

 wheel ; a purely mechanical case is given in which there is a 

 similar failure of Lagrange's method for an analogous reason. 



No. 20. Sur les principes fondamentaux de la Theorie des 

 Nbmbres et de la Geometrie ; par H. Laurent. Pp. 68. 



H. A. B. 



15. Lehrbuch der Physik ; von O. D. Chwolson. Deutsche 

 Ubersetzung von H. Pflaum. In vier Bande. Erster Band ; 

 pp. xx + 792. (Braunschweig : F. Vieweg & Sohn.) — In 1897 a 

 text-book of physics, in Russian, by Prof. Chwolson of the Uni- 

 versity of St. Petersburg, was published, and a second and revised 

 edition appeared in 1900. In the meanwhile the work had 

 received such high praise from physicists whose knowledge of 

 the language permitted them to read it that a German translation 

 was undertaken, the first volume of which has recently been 

 issued. Although of large size and comprehensive in character, 

 the work is primarily a text-book for students rather than a rival 

 of such works of reference as Winkelmann's Hand-book ; and it 

 is for its pedagogical excellences that it has been especially com- 

 mended. An examination of the present volume goes far toward 

 justifying in the mind of the reader these commendations ; the 

 arrangement and classification are logical and especially convenient 

 for teaching ; the statements are clear and exact with most care- 

 ful discrimination between experimental fact and hypothesis, and 

 the mathematical demonstrations are simple and elegant. But 

 the most striking achievement of the author (considering its 

 difficulty in an elementary text-book) is the constant maintenance 

 of the right point of view and proper perspective ; so that the 

 student who uses this book with intelligence can scarcely fail to 

 understand what the object of physics really is, and what are its 

 methods and limitations ; the general introduction, in particular, 

 displays these qualities to a marked degree. The second sub- 

 division of the present volume is devoted to mechanics, including 

 w r ave motion and the elementary theory of potential ; the third 

 to apparatus and methods of measurement ; the fourth, filth and 

 sixth to the study of gases, liquids and solids, respectively. The 

 three succeeding volumes in order will deal with sound and 

 radiation, heat, and electricity and magnetism. Although ele- 

 mentary in character, the treatment is very complete, and at the 

 end of each chapter a list of references is given to other books 

 and to the periodical literature of the subject. The book is 

 probably too large and too thorough-going to be used as a text- 

 book in any American college, but it will doubtless be useful 

 indirectly to many teachers. h. a. b. 



II. Geology and ISTatueal Histoey. 



1. JVetv Mineral Names. — Anapite. A new potassium iron 

 phosphate occurring at Anapa on the Black Sea is given the 

 name Anapite by A. Sachs. The mineral occurs in crystals about 



