Febbuaky 18, 1010] 



SCIENCE 



267 



tion of this work gradually became the gener- 

 ally recognized starting-point, and of late years 

 has become ofBeially so recognized in all mod- 

 ern codes of nomenclature. In the meantime 

 the British Museum Catalogue had reached 

 completion on the old basis, and a strongly 

 grounded spirit of conservatism compelled 

 adherence to the practises of earlier days. 

 Hence we have in the " Hand-list " a work 

 that, while of the highest utility as a cata- 

 logue of the genera and " species " of birds, is 

 out of touch at many points with modern 

 ways; but, with this fact in mind, the special- 

 ist can easily avoid the pitfalls. It should 

 hence be remembered (1) that names, generic 

 or specific, founded before 1766 (except Bris- 

 sonian names) are here ignored; and (2) that 

 emended forms of names are employed where 

 a name as originally propounded is believed 

 to have been incorrectly constructed. 



It is with the greatest regret that, in re- 

 viewing the " Hand-list " from the present 

 generally accepted standpoint of nomencla- 

 ture, these criticisms seem necessary. No one 

 can have a greater admiration for Dr. 

 Sharpe's work in systematic ornithology than 

 the present reviewer, who regards him as 

 without a peer in his special field of activity, 

 and his " Hand-list " as a fitting close to a 

 long series of monumental works in ornithol- 

 ogy. 



J. A. Allen 



Anfangsgrunde der Maxwellschen Theorie 

 verhniipft mit der EleUronentheorie. By 

 Franz Eicharz. 8vo, pp. ix -\- 245. Leip- 

 zig, Teubner. 1909. 



This book, developed from a course of lec- 

 tures to teachers, assumes on the part of the 

 reader a knowledge of elementary experi- 

 mental and theoretical electricity, as well aa 

 some acquaintance with analytical mechan- 

 ics, potential theory and differential equa- 

 tions. It is not intended as in any way a 

 complete exposition of electrical theory, but 

 aims, and with success, to treat clearly and 

 with precision a number of fundamental sub- 

 jects, ranging from simple problems in elec- 

 trostatics to the electromagnetic theory of 



light in media at rest. The treatment, while 

 exact and of necessity involving many equa- 

 tions, is physical rather than mathematical. 

 In the opinion of the reviewer it would be 

 improved by making less use of potentials. 

 Considerable use is made of dynamical and 

 thermal analogies, and the electron theory ia 

 in evidence throughout, contributing much to 

 the interest of the work. But few statements 

 in the text are in need of correction. Ac- 

 cording to one of these true magnetism (div 

 jxH) corresponds to the magnetic pole strength 

 of experimental physics, although a virtual 

 modification of this statement occurs a little 

 later. Also the electromotive force of a gen- 

 erator supplying power is referred to as the 

 potential difference between its terminals on 

 open circuit — an old error of remarkable 

 vitality. The reviewer often wonders what 

 one who defines the electromotive force of a 

 generator in this way thinks about a series 

 dynamo, for example, whose electromotive 

 force for normal current may be thousands of 

 volts, while its terminal potential difference on 

 open circuit is practically nothing. Accord- 

 ing to another statement of the author, no 

 direct experimental proof had been given, 

 when the book was written, of the development 

 of an electric intensity in an insulator by a 

 changing magnetic field — the converse of the 

 Rowland effect. It will be remembered, how- 

 ever, that such a proof was given some years 

 ago by the experiments of Cremieu, as cor- 

 rectly interpreted by Larmor and H. A. Wil- 

 son. With only a few oversights in need of 

 attention, the work as a whole is very free 

 from errors. The printing is excellent. 



S. J. Barnett 



SCIENTIFIC JOURNALS AND ARTICLES 

 The opening (January) number of Volume 

 11 of the Transactions of the American Math- 

 ematical Society contains the following 

 papers : 

 H. F. Bliehfeldt: "Theorems on simple groups." 

 Virgil Snyder: "Infinite discontinuous groups 

 of birational transformations which leave certain 

 surfaces invariant." 



E. B. Lytle : " Proper multiple integrals over 

 iterable fields." 



