Chemistry and Physics. 463 



equations expressing electro-magnetic conditions, and on the ver- 

 ification of such equations by the aid of the dimensions of the 

 physical quantities involved in the several terms. On the whole, 

 the book will probably appeal most to students who already have 

 a fair knowledge of the subject and who desire to review the 

 ground under the guidance of a reliable author. h. s. tj. 



11. La Moderna Teoria del Fenomeni Fisici : Radioattivita. 

 Ioni, Elettroni ; by Augusto Righi. Terza Edizione. Pp. x, 290. 

 Bologna, 1907 (Nicola Zanichelli). — This third edition of Profes- 

 sor Righi's admirable popular work follows the first edition in 

 less than two years after its appearance, a success which is due 

 to its remarkably clear style and logical treatment of the impor- 

 tant phenomena which are, as yet, hardly familiar to students not 

 possessed of a technical training in physics. The very limited 

 use of mathematical language in the book is confined to foot-notes 

 and it is not essential to a good understanding of the topics 

 discussed. c. s. h. 



12. La lonizzazione e la Convezione Flettrica nei Gas; by 

 Lavoeo Amaduzzi. Pp.386. Bologna, 1907 (Nicola Zanichelli). 

 — The aim of this interesting volume can perhaps be most speed- 

 ily defined by naming the titles of the chapters. Chapter I, The 

 Electron : IT, Canal Rays : III, Rontgen Rays : IV, Ionization 

 by means of Rontgen Rays : V, Characteristics of Ions : VI, Other 

 Means of Ionization : VII, The Electric Discharge. 



The chapters are followed by about fifty pages of appendices 

 and twelve pages of useful, and apparently exhaustive, bibli- 

 ography. The treatment of the subjects named is such as to adapt 

 the work for a reader with an ordinary training in the philosophy 

 of physics, and it is difficult to imagine how the author's part 

 could have been better done. The clear typography and liberal 

 margins which the publisher has provided make the volume a 

 model of what such scientific summaries should be. c. s. h. 



II. Geology and Natural History. 



1. Geological Survey of Western Australia. Third Report 

 on the Geological Features and Mineral Resources of the Pilbara 

 Goldfield ; by A. Gibb Maitland. Bulletin No. 23, pp. 87, with 

 7 geological maps and 13 figures. Perth, 1906 (Fred. W. Simp- 

 son, Government Printer). — Taken in connection with bulletins 

 Nos. 1 5 and 20, the present report furnishes a general summary 

 of the geological as well as the mining prospects of a large area 

 in northern West Australia. The formations recognized are 

 arranged as follows, beginning with the oldest : 1. Warrawoona, 

 gold-bearing metamorphic quartzites, conglomerates and green- 

 stone schists, probably Archean. The tin-bearing granite and 

 gneiss which occupies the larger portion of the Pilbara district is 

 intrusive into the Warrawoona. 2. Mosquito Creek, grits, shales, 



