io6 



NATURE 



[November 23, 191 1 



number of riders has been included to test the 

 student's grasp of the theory. 



(6) The treatment in this volume is practical rather 

 than mathematical, and is designed for the use of 

 those taking a course in mechanical drawing. 

 Elementary in character, it provides a thorough intro- 

 ductory account of the subject. The first chapter con- 

 siders in great detail the nature and meaning of ortho- 

 graphic projection, using three planes of reference. 

 Next an account is given of the projection of a straight 

 line and the method of obtaining the true length of a 

 line in space. After this follow successively the treat- 

 ment of the intersection of planes, curved lines, and 

 surfaces, and the traces of lines and planes with 

 various applications, and the book closes with a 

 description of isomotric projection. The excellence of 

 the diagrams i'; a fi ature which calls for special 

 remark. The explanations are clearly put, and the 

 work is so arranged that no special mathematical 

 ability is required. 



(7) The absence of spherical trigonometry from the 

 ordinary school syllabus is both surprising and unfor- 

 tunate in view of the practical applications which may 

 be made ; nor can this omission be excused on the 

 score of diflRculty, since the analysis is scarcely more 

 difficult than that of the corresponding work in plane 

 trigonometry. The explanation, of course, lies in the 

 fact that it is at present excluded from the schedule 

 for university scholarships. The book before us con- 

 tains in a rather unduly elaborate form the kind of 

 course which might be incorporated in a school pro- 

 gramme. After a preliminary discussion on spherical 

 triangles, the methods for solving right-angled tri- 

 angles are first explained, and then the general case 

 of oblique-angled triangles is considered. Great care 

 is taken to explain the best way of arranging the work 

 in numerical examples. The concluding chapters of 

 the book give applications to geometry, astronomy, 

 and navigation. Theory is throughout subordinated to 

 practice, and those who require a comprehensive work- 

 ing knowledge of the methods of this subject cannot 

 do better than read through this book. 



OUR BOOK SHELF. 

 L' Evolution de I'Electrochimie. By Prof. VV. Ost- 



wald. Translated by E. Philippi. Pp. ^ 266. 



(Nouvelle Collection scientifique : directeur, Emile 



Borel.) (Paris : F^lix Alcan, 1912.) Price 3.50 



francs. 

 The evolution of electrochemistry affords probably one 

 of the most interesting chapters in the history of the 

 progress of chemical knowledge. Since the birth of 

 this branch of chemistry may be regarded as dating 

 from the discovery of so-called voltaic electricity, the 

 period covered by its history is limited to a little more 

 than a century. The comparative shortness of this 

 period has certain obvious advantages, and the many 

 discoveries of fundamental importance made by in- 

 vestigators in the field of electrochemistry, as well as 

 the development of theoretical knowledge relating to 

 the nature of and connection between electrical and 

 chemical energy afford particularly attractive material 

 for an historical study. 



The account presented by Prof. Ostwald, who may 

 be legitimately regarded as the greatest authority on 

 the subject, is admirable in every way, and a more 



NO. 2195, VOL. 88] 



fascinating description of the development of a branch 

 of science cannot well be imagined. The subject- 

 matter and mode of treatment is indicated sufficiently 

 by the titles of the sections into which the trxt is 

 divided, viz. : (i) introduction; (2) prehistory-; (3) Gal. 

 vani and Volta; (4) Ritter and Davy; (5) from r.radav 

 and Daniell to Hittorf and Kohlrausch ; (6) 

 motive forces; (7) the beginning of technical • 

 chemistry; (8) van 't Hoff and Arrhenius; (9) the 

 ionists; (10) modern electrochemical industry; (11) the 

 electron. In this final chapter a very brief but well- 

 written account is given of the results attained in the 

 investigation of the conductivity and the ionisation of 

 gases, which results have given so much impetus to 

 the development of the electron theory. 



Much of the material collected and condensed 

 this little volume is to be found in Ostwald's coin- 

 pendious treatise on " Elektrochemie," published in 

 i8q6. This book, largely on account of its size, is 

 comparatively little known amongst students of phys- 

 ical chemistry, and the appearance of a smaller wf>'^>' 

 is therefore in itself an event of some importance. 



The Life and Love of the Insect. By J. H. F;il 

 Translated by A. T. de Mattos. Pp. x+. 

 (London: A. and C. Black, 1911) Price 55. net. 

 Several translators have already drawn from liie 

 abundant well of Fabre's entomological studies, and 

 the volume before us is a pleasant addition. We like 

 the grateful tribute to the veteran which the preface 

 pays, and the quotation from Maeterlinck in regard 

 to'this "Insects' Homer," "who is one of the m 

 profound and inventive scholars and also one of 

 purest writers, and, I was going to add, one of 

 finest poets of the century that is just past." 



The book tells us of the sacred scarabee supren 

 inspired by the instinct of maternity to wond* : 

 industry and not less wonderful art; of the Spai 

 Copris which kneads a large loaf and divides it 

 pills, one for each egg; of the common dung-be' 

 (Geotrupes), who belong to the public health serv 

 and are often deservedly decorated; of Minotai 

 typhaeus, a black beetle of the sheep's pasturage, v 

 burrows and bakes, and even makes sausages; of 

 ringed Calicurgus, which first stings its capti: 

 spider in the mouth, paralysing the poison fangs, 

 then, safe from being bitten, drives in its poisf 

 needle with perfect precision at the thinnest par: 

 the spider's cuticle between the fourth pair of \> 

 of the leaf-rolling Rhynchites, which spends the ^^ i 

 day in making an inch-long cigar with eggs betv 

 the layers of the scroll ; and of the mother of 

 Halictus bee family, who becomes in her old age 

 portress of the establishment, shutting the door ^ 

 her bald head when strangers arrive, opening it 

 drawing aside when any member of the housel 

 appears on the scene. And so the stories run. fu! 

 dramatic situations and romantic interest. We k: 

 not which to admire the more, Fabre's style or 

 eyes. The translator has given us a fine render' 

 which reads like the original. 



(i) Aids to Bacteriology. By C. G. Moor and W;r. 

 Partridge. Second edition. Pp. viii + 240. (I 

 don : Bailli^re, Tindall, and Cox, 191 1.) F 

 35. 6d. net. Paper, 35. 

 (2) Aids to Pathology. By Dr. H. Campbell. Sec 

 edition. Pp. viii + 228. (London : Bailli^re, I 

 dall, and Cox, 191 1.) Price 3s. 6d. net. 

 These two little books contain a large amoun: 

 information in a small space. Neither professes tu 

 more than an outline of the subject of which it treats, ^ 

 but both seem to be successful in their aim — that of 

 acting as epitomes for the student and practitioner. 



