August 12, 1897] 



NA TURE 



341 



appendices, addenda, and endless footnotes (with supple- 

 mentary notes to these). On pp. 34-39 we have some 

 240 lines of footnotes to 34 lines of text 1 All this makes 

 the book rather irritating reading, although the notes 

 are valuable and often very amusing. Thus, in a note 

 on the permanence and identification of the ego (p. 4), 

 we read : — 



" Not long ago, after a trying railway journey by night, 

 and much fatigued, I got into an omnibus, just as another 

 gentleman appeared at the other end. ' What degenerate 

 pedagogue is that, that has just entered,' thought I. It 

 was myself: opposite me hung a large mirror. The 

 physiognomy of my class, accordingly, was much better 

 known to me than my own." 



The author adopts a consistent, monistic conception of 

 Miiller's doctrine of the "specific energies," assuming 

 that there are as many physico-chemical neural processes 

 as there are distinguishable qualities of sensation, and 

 regards sensations as the elements of the world. The 

 principle of continuity (which has its root in an effort for 

 economy) and the principle of sufficient determination 

 (or differentiation) are employed to investigate the con- 

 nection between psychologically observable data and the 

 corresponding physical (or physiological) processes. It 

 is throughout assumed that there is a complete parallelism 

 between the psychical and the physical— that there. is no 

 real gulf between the two. After a highly interesting 

 discussion of the space-sensations of the eye, the difficult 

 subject of time-sensation is attacked ; then sensations of 

 tone. Here we have a criticism of Helmholtz's analysis 

 of the characteristic sensation corresponding to each 

 musical interval, and a new hypothesis (containing a 

 more positive factor in the explanation than the mere 

 absence of beats) is developed at some length. 



In spite of its modest dimensions the book is one 

 which no future writer on the subject can afford to 

 neglect. The physicist will find in it much to stimulate 

 inquiry. It offers a refreshing contrast to much that is 

 written on psychology in the originality of its views, of 

 the observations on which they are based, and of the 

 experiments which are devised to test them. pv. 



Euclid, Books I.-IV. (The University Tutorial Series.) 

 By Rupert Deakin, M.A. Pp. viii -I- 308. (London : 

 \V. B. Clive, Univ. Corres. Coll. Press, 1897). 

 Of the numerous books which have appeared in the last 

 few years on the propositions of Euclid, each has been 

 put forward as possessing some particular feature of ex- 

 cellence. The writers of these claim, in some cases, that 

 the student cannot have too much detail and explanation 

 given to him in the text, while others aim at a pure cut 

 and dried edition with a great number of accompanying 

 exercises. .Each of these types may have their good 

 qualities, for the successful teaching of Euclid is by no 

 means an easy task. 



In the book before us the author has, to a great extent, 

 struck a mean between both these lines. His aim has 

 been to lay the proof of each proposition concisely, and 

 yet not too elaborately, before the student, without ren- 

 dering the proposition too long to cause perplexity and 

 bewilderment. A few easy exercises are added after each 

 proposition, on which the student is advised to exercise 

 his ingenuity. 



At the conclusion of each book are inserted a useful 

 series of notes bearing on the propositions, pointing out 

 the chief points of connection and difference between 

 each ; then follows a brief but clear summary of the 

 results arrived at in the book under discussion. Teachers 

 might make the students familiar with this summary at 

 an earlier period ; and if this be done judiciously, a general 

 survey of the propositions, showing how they are con- 

 nected with one another, would render the subject more 

 interesting. 



NO. 1450. VOL. 56] 



Further, some important additional propositions and 

 sets of miscellaneous riders, arranged under different 

 headings, are added, some of which should always be 

 attempted. 



The author having had more than twenty years' ex- 

 perience in teaching this subject to both large and small 

 classes, the chief difficulties that are generally met with 

 have received special attention. As a class-book the 

 volume should find much favour. 



The Voyages made by the Sieur D. B. to the Islands 

 Dauphini or Madagascar and Bourbon or Mascarenne 

 in the Years 1669,' 1670, 1671 and 1672. Translated 

 and edited by Captain Pasfield Oliver, late Royal 

 Artillery. With facsimile maps and illustrations. 

 Pp. xl -I- 160. (London : David Nutt, 1897.) 



This little volume might well have been produced by the 

 Hakluyt Society, with the publications of which it is 

 uniform. It is the translation of a rare French book, 

 describing the voyages of one Dubois in the seventeenth 

 century. The translation well reflects the quaintness of 

 the original, although the attempt to imitate the English 

 style and spelling of two centuries since are not always 

 very happy. Captain Oliver has supplied an introduc- 

 tion tracing the history of Dubois, and of the French 

 colonies in the islands of the Indian Ocean during his 

 lifetime ; as well as a series of notes on various points 

 mentioned in the text. Apart from the historical interest 

 attached to all early travels the narration of the Sieur 

 D. B. has a certain original value, as he describes from 

 his own observations several of the extinct birds of 

 Reunion, especially the Solitaire and Oiseau bleu, which 

 were contemporaries of the Dodo of Mauritius, and 

 closely resembled that bird in their habits. These de- 

 scriptions have long since been fully discussed by ornith- 

 ologists, both in France and England. 



The book is illustrated by a photograph of the sur- 

 viving giant tortoises which have been removed from the 

 Mascarenes to Mr. Rothschild's park at Tring, and 

 drawings of a number of birds, together with repro- 

 ductions of modern photographs of the people and pro- 

 ducts of Madagascar. In view of the renewal of French 

 colonisation in Madagascar, the shrewd observations and 

 far-seeing advice of the old traveller may be worthy of 

 attention. The book well deserved translation, and 

 Captain Oliver is to be congratulated on the excellent 

 manner in which he has brought it out. 



Elementarcurs der Zootomic in fiinfzehn Vorlesiingen. 



Von Dr. B. Hatschek und Dr. C. J. Cori. Pp. 



viii -I- 103. (Jena : Gustav Fischer, 1896.) 

 This little book has been compiled by Prof Hatschek 

 and Dr. Cori, as a guide to dissection, for the use of 

 elementary students attending lectures in Prag. The 

 fact that no less than ten animals are dealt with in little 

 over one hundred octavo pages sufficiently indicates the 

 scope of the work, which contains simply concise notes 

 of the more important characters of the animals treated, 

 and technical directions for dissecting them. The 

 characters referred to are always such as can be demon- 

 strated by simple dissection, without complicated methods 

 of preparation, and without the use of the compound 

 microscope. It follows from this that the Protozoa are 

 entirely excluded, as are also the Cojlentera. 



The names on the title-page are a sufficient guarantee 

 that the information contained in the book is accurate, 

 so far as it goes, and the illustrative drawings are 

 adequate to the purpose in view. No doubt Prof. 

 Hatschek's students will find the book of service to them 

 in their efforts to follow his lectures and laboratory teach- 

 ing ; but there is no reason why English students should 

 desert the works, such as that of Marshall and Hurst, 

 which so many of them at present use. 



