52 



NATURE 



\Nov. 15, 1888 



very difficult and abstruse subject. The book is divided 

 into three parts : viz. Part I. Researches relating to the 

 Law of Contraction, which contains the well-known papers 

 of Tigerstedt, Griitzner, and Hering on this subject ; 

 Part II. Researches relating to Secondary Electromotive 

 Phenomena, containing papers by Du Bois-Reymond, 

 Hering, Hermann, and Biedermann ; Part III. Re- 

 searches on the Electrical Phenomena of Certain Elec- 

 trical Fishes, by Du Bois-Reymond. In addition, a short 

 summary of two or three of the most recently published 

 papers on the subjects treated of in this volume is given 

 in the form of an appendix. 



The memoirs selected for translation in Parts I. and 

 II. form a group of papers which are most interesting to 

 all those who are anxious to obtain more than a text-book 

 acquaintance with the difficult questions treated of in 

 them. The translations have been made with great care 

 and accuracy, and with a careful attention to style, though 

 naturally the original German construction is more 

 palpable in some than in others ; it would, however, be 

 invidious to select any individual memoirs in this respect. 

 The editor is also to be congratulated upon the manner in 

 which the especially difficult German phraseology inherent 

 to the nature of the subject has been rendered into 

 English. Uniformity of translation among the different 

 translators has been fairly well attained. Perhaps the 

 most noticeable discrepancies are in the translation of the 

 words " Liicke " and " ScAweZ/e." The phenomenon of 

 the " Liicke " is called by one translator the phenomenon 

 of the " gap," and by another the phenomenon of the 

 " hiatus " ; of the two, " gap " is perhaps preferable. The 

 almost untranslatable word " Schwelle " is sometimes 

 rerxdered as "limen," at other times as "threshold"; of 

 these two, " limen " sounds best. It is also a pity that the 

 editor has not settled whether the opposite pole to the 

 anode ought to be spelt with a " c" or a "k " : cathode 

 and kathode are pretty equally distributed throughout 

 this volume. As to the arrangement of the different 

 memoirs, they all follow each other in natural sequence, 

 with the exception of the second and third papers of 

 Tigerstedt, which ought to have been transposed, as the 

 author assumes in No. 2 that No. 3 has already been 

 read. 



Not the least prominent part of the work is the 

 preface, in which the editor briefly links together the 

 various memoirs. As it will seem to many that this 

 should be the most important part of the whole book, 

 it is to be regretted that it is not fuller and also 

 more critical ; for undoubtedly any collection of trans- 

 lations of foreign memoirs upon a special biological 

 subject would be very much more valued by English 

 readers if the recognized English authority on that 

 subject prefaced the translations with a critical com- 

 mentary embodying his own views. 



Also, as the object of the book is presumably to enable 

 students and physiologists who do not read German 

 easily to understand the present position of the physio- 

 logy of nerve and muscle without having to refer to the 

 original papers in the German journals, it would have 

 been better to afford more indication as to the nature of 

 the contents of previous papers which are referred to by 

 the authors but have not been included among the trans- 

 lations. This might have been done by the more copious 



use of footnotes, or by the translation of one or two more 

 papers. Thus in Biedermann's paper the whole argument 

 is so bound up with his previous papers on the heart of 

 the snail and the muscle of the anodon, that it would have 

 been better to translate the three papers rather than only 

 one. If this had been done, the book would have been 

 large enough without Part HI. and there would have 

 been no harm in that, for in the first place the physiology 

 and histology of the electrical organ might well be 

 treated of in a separate volume of memoirs, and in the 

 second place, the papers included in Part III. are all 

 by the same author, and can hardly be considered so 

 important as those in Parts Land II. Thus Du Bois- 

 Reymond's statement as to " irreciprocal conduction " is 

 based upon an error of observation, according to the 

 recent paper of Gotch in the Proceedings of the Royal 

 Society, and is therefore hardly worthy of a place in these 

 memoirs. 



The book is essentially of the nature of an experiment, 

 and it is to be hoped that the demand for it will be suffi- 

 cient to repay the editor for the time and trouble which 

 he has spent in carrying out his task, and to encourage 

 him to bring out a series of similar volumes dealing with 

 a number of the most important of those biological 

 questions which are the subject of controversy at the 

 present time. 



OUR BOOK SHELF. 



Examples in the Use of Logarithms. By Joseph Wolsten- 

 holme, Sc.D. (London : Macmillan and Co., 1888.) 



Practical Logarithms and Trigonometry. By J. H. 

 Palmer. (London : Macmillan and Co., 1888.) 



These are two books for the use of mathematical students 

 from the hands of practical teachers, who may be assumed 

 to be well acquainted with the difficulties met with by 

 students. 



The first one consists entirely of rules and their appli- 

 cation to examples. The earliest examples are on the 

 extraction of logarithms fro m tables. Then follo w the 

 reductions of Va- -f b'^ and sJb- + c" — ibc cos A, after 

 which come the various solutions of triangles, finally con- 

 cluding with a lengthy series of examples on the calculation 

 of the parts of tetrahedra when the sides are given. The 

 author's experience has indicated that examples of the 

 latter class are especially useful in teaching the habitual 

 accuracy which it is desirable to attain, and another 

 reason for their introduction is that they afford pre- 

 liminary practice in the solution of spherical triangles. 

 Such, then, is the first book, and no one will contradict 

 us when we remark that a student who carefully works 

 out the examples given cannot fail to become perfectly 

 familiar with logarithms and their applications. 



The range of the other book is a little wider. Beginning 

 with involution and evolution treated arithmetically, and 

 following with geometrical and trigonometrical definitions, 

 the author leads to logarithms and their simpler applica- 

 tions. The aim of the book is to give a thorough 

 practical knowledge of the use of logarithms and the 

 solution of plane triangles and problems in trigonometry. 

 The general plan adopted is first to state a rule, give 

 worked examoles, and then to give a number of exercises 

 on each rule, 'which may be tested by the answers given. 



The omission of the proofs of the rules and formulae 

 renders the book liable to be looked upon as a cram 

 book, but it is apparently intended mainly for the use of 

 those who simply wish to know how to use logarithms 



