56 



NATURE 



[March 20, 19 13 



fusely illustrated in the text, and contains one 

 coloured plate showing the elements and structures 

 brought to light by the application of various 

 methods, staining agents and other reagents. A 

 lull bibliography is appended, but an index is 

 lacking, which is a great mistake. 



(2) The second volume is one more adapted 

 to the needs of the biologist or of the 

 general reader, inasmuch as it gives a general 

 survey of the structure and functions of 

 the bacteria and of their activities. The first 

 two chapters are devoted to a consideration 

 of the size, form, development, and occurrence of 

 the bacteria and to the methods employed in study- 

 ing and cultivating them. Chapters iii.-vi. deal 

 with their morphology and the structure of the 

 bacterial cell. As regards classification (chapter 

 vii.), the author divides bacterial organisms into 

 two suborders, the Haplobacterinae and the 

 Desmobacterina;, the former including the single- 

 celled bacteria, the latter the thread-forming 

 organisms such as Leptothrix, Crenothrix, Clado- 

 thrix, and Beggiatoa. As an appendage of the 

 Haplobacterinas he recognises the Mycobac- 

 teriaceas (" Pilzbakterien "), in which he places 

 such organisms as the tubercle bacillus and 

 Actinomyces, and the Myxobacteriaceae or " slime 

 bacteria." Truly the classification of the bacteria 

 is still in a very unsatisfactory condition ! 



\ ariatioh and mutability among the bacteria are 

 discussed at some length, after which the condi- 

 tions of life and general physiology of the bacteria 

 are dealt with : assimilation and dissimilation, 

 fermentation, nitrogen fixation, &c. Finally, the 

 occurrence and distribution of bacteria on the 

 earth's surface, in arable, grass, and wooded 

 lands, in water and dwellings, are considered. 

 The book is exceedingly well conceived, and con- 

 tains a mass of trustworthy information with 

 sufficient references to the literature. It is well 

 printed and illustrated, and is supplied with 

 adequate indexes to the matter it contains and 

 to the authors mentioned. 



R. T. Hewlett. 



OUR BOOKSHELF. 

 Guide Scientifique du Gdographe-Exploratcur. 

 By P. Crepin de Beauregard. Pp. X + 250 + 

 2 plates. (Paris: Gauthier-Villars, 1912.) 

 Price 10 francs. 

 This work is not intended for the ordinary 

 traveller who wishes to prepare a sketch-map of 

 the country which he traverses, and to determine 

 with moderate accuracy the position of his halting 

 places. M. Crepin de Beauregard, who has had 

 much experience of surveying both in France and 

 in Indo-China, has. prepared a handbook for the 

 NO. 2264, VOL. 91] 



trained surveyor who has a certain knowledge 

 of mathematics and has to undertake work 

 of considerable accuracy in new countries in order 

 to provide a control for subsequent topographical 

 surveys. The treatment is consequently in a large 

 degree theoretical, though actual examples from 

 work in the field are given, but the simpler and 

 less precise methods of topographical surveying 

 are not included. 



The first chapter deals mainly with the trigono- 

 metrical formulae involved, while in the second the 

 theodolite is discussed as being the instrument 

 employed, and the errors introduced by dislevel- 

 ment, &c, are investigated. Coming to the 

 astronomical determinations which the surveyor 

 requires to make in the field, the most suitable 

 methods of determining the local time, the latitude 

 of a station, and the azimuth of a mark are fully 

 discussed theoretically, and an example of each is 

 worked out. In these cases each observation made 

 is worked out separately and a mean value of 

 the results is obtained, though the probable error 

 is not considered. 



In that part which treats of triangulation the 

 author deals with the computations which are 

 necessary in first and second order triangulation 

 where the surface is treated as that of a spheroid, 

 and in third order work where spherical formula? 

 suffice. Map projections occupy a chapter, and 

 these are not limited to those types which are 

 likely to be employed by those who are surveying 

 a new country, but include all the principal types. 

 The book should be of much use to those trained 

 surveyors who are steadily extending the network 

 of triangulation in Algeria and Tunis, in Indo- 

 China and Madagascar. H. G. L. 



Introduction to the Rarer Elements. By Philip E. 

 Browning. Pp. xii + 232. Third edition. (New 

 York : John Wiley and Sons ; London : Chap- 

 man and Hall, Ltd., 1912.) 

 To this edition of Dr. Browning's book several 

 additions have been introduced and numerous 

 changes made. The chapter on qualitative analysis 

 has been enlarged by the inclusion of new dia- 

 grams, new material has been added to the chapter 

 on technical applications, and a table of spectro- 

 scopic lines and plates showing typical spectra 

 have been introduced. The second edition was 

 reviewed in Nature of April 15, 1909 (vol. lxxx., 

 p. 182). 



A First Book of Electricity and Magnetism. By 

 W. Perren Maycock. Fourth edition. Pp. 

 xxii + 351. (London: Whittaker and Co., 

 1913.) Price 2s. 6d. net. 

 The first edition of Mr. Maycock's little book was 

 reviewed in the issue of Nature for January 14, 

 1892 (vol. xlv., p. 248). The present issue has 

 been revised thoroughly and enlarged considerably, 

 and the author has been successful in his desire 

 to "carry the reader over the threshold of a sub- 

 ject whose theoretical and practical extents are 

 verv far-reaching. " 



