^58 



NA TURE 



[December io, 1908 



those ideas already existing in the minds of physicists 

 before the discovery of the first of the radio-active 

 substances. 



In summarising worli on points about which there 

 is difference of opinion the author shows a com- 

 mendable caution, and his verdict usually appeals to 

 one as safe ; perhaps an exception occurs where he 

 states that the available evidence indicates that the 

 activity of radium C can be altered by change of 

 temperature. 



The book constitutes a valuable addition to the 

 literature of radio-activity, and can be recommended 

 to those interested in that fascinating subject. 



J. A. M. 



T/ze Psychology and Training of the Horse. By 

 Count E. M. Cesaresco. Pp. xvi-l-334. (London : 

 T. Fisher Unwin, 1906.) Price los. 6d. net. 

 In spite of its title, this book is no addition to our 

 rapidly multiplying collection of works on animal 

 psychology. It cannot be called scientific in the 

 strictest sense. Modern psychological science en- 

 deavours so far as possible to found its conclusions 

 on experimental treatment of its subject-matter, and 

 in the case of the lower animals, where direct intro- 

 spection is impossible and analogy unsafe, it refuses 

 to accept conclusions not obtained in this way. But 

 no records of experiments performed on the horse 

 are to be found in Count Cesaresco's book. Descrip- 

 tion and anecdote there is in plenty, and that of the 

 greatest interest, but all explanation is a priori and 

 decidedly anthropomorphic. Psychological terms are 

 used wherever possible to give precision to a descrip- 

 tion the main value of which is independent of such 

 adventitious adornments. Not that the psychology is 

 necessarily incorrect ; on the contrary, it appears to 

 have probability on its side, only it cannot lay claim 

 to the title of strict science. 



The practical knowledge displayed by the author is 

 full and precise, and, doubtless, will alone suffice to 

 commend the book to horse-lovers. Indeed, the earlier 

 " psychological " chapters on the nature of the horse's 

 mind form a description written merelv ad hoc, pre- 

 fatory to the main theme of the book, viz. the best 

 methods that may be employed in the training of the 

 horse for the service of man. These methods are 

 based on the assumption that the horse learns by 

 association of his actions with their pleasurable or 

 painful effects, and by no higher process. No record 

 is given of any attempt to iustifv this assumption 

 experimentally, .^t times the book barely rises above 

 platitude, and there is also much unnecessary repeti- 

 tion strewn up and down its pages. The absence 

 of any of the elegances of style is doubtless to be 

 accounted for by the fact that the author is writing 

 in a language not his own. Despite these draw- 

 backs, the book is quite readable, and thoroughly 

 justifies its existence. 



Elementary Botany. By Dr. E. Drabble. Pp. vi-H 



234. (London : Edward Arnold, n.d.) Price 2s. 6d. 



Biologie unsercr einheimischen Phancrogamcn. By 



M. Wagner. Pp. xii-l-iqo. (Leipzig and Berlin: 



B. G. Teubner, 1908.) Price 6 marks. 



It would seem almost impossible to devise a new 



disposition of matter in an elementary text-book, but 



it must be allowed that Dr. Drabble has drafted a 



setting which differs in arrangement from the standard 



books of its kind. He begins with an explanation 



of physiological principles as a preparation for the 



interpretation of morphological structure, and touches 



on plant modifications and classification. The course 



outlined is verv workable, and will certainly find 



NO. 2041, VOL. 79] 



favour with not a few teachers in schools. The text 

 is characterised by accurate and logical exposition, 

 combined with a sufficiency of illustration to make 

 the points clear. Experiments for testing the physio- 

 logical deductions are suggested. These might in 

 several instances have been more fully detailed with 

 advantage. The figures are not so creditable, and 

 some are unnecessarily crude, such as the crocus 

 conns and the fruits on p. 165, while Fig. 8 supplies 

 an example of how not to set up the experiment. 

 These are, however, slight defects when compared 

 with the general excellence of the subject-matter. 



The botanical volume, written by Dr. M. Wagner, is 

 in no sense a text-book for use in schools, but pro- 

 vides a compendium of the various contrivances, 

 mechanisms, and characteristics of flowering plants. 

 Thus, in a chapter on light requirements, the author 

 schedules a series of contrivances serving to intercept 

 and absorb the light rays ; then the various types of 

 climbers are catalogued, and the methods of guarding 

 against destruction of chlorophyll in the leaves are 

 outlined. Under each heading a list of the plants 

 showing the particular character is enumerated. The 

 book is therefore intended primarily for reference, 

 and, doubtless, teachers will be glad to add it to 

 their librarv. The information is arranged under the 

 general headings of nutrition and reproduction, and 

 the chapters follow physiological, not ecological, con- 

 ceptions. The author states in the preface that he 

 has collated his facts from the works of Haberlandt, 

 Kerner, Ludwig, and other writers. It would have 

 added greatly to the value of the book if he had 

 given references to the original sources. 



The Deinhardt-Schlomann Series of Technical Dic- 

 tionaries in Six Languages: German, English, 

 French, Russian, Italian, Spanish. By Alfred 

 Schlomann. \'ol. iv. Internal Combustion Engines. 

 Compiled by Karl Schikore. Pp. x-t-6iS; with about 

 1000 illustrations and numerous formulae. (London : 

 Archibald Constable and Co., Ltd., 1908.) Price 8.v. 

 net. 

 In noticing the first volume of this series of dictionaries 

 in our issue for May 3, 1906 (vol. Ixxiv., p. 6), descrip- 

 tions of the objects of the series and the methods of treat- 

 ment were given. The present volume deals with the 

 following subjects among others : — gases and oils ; the 

 theory, construction, equipment and erection of internal 

 combustion engines ; ' materials and their economical 

 use; complete plants; and general working and testing. 

 The illustrations, though of necessity small, since the 

 volume is of pocket size, are generally remarkably 

 clear. The excellent alphabetical index with which the 

 volume is provided makes reference easy and vvil' 

 greatly enhance the popularity of the dictionary among 

 technical students and workers. 



Highways and Byivays in Surrey. By Eric Parker. 



With illustrations by Hugh Thomson. Pp. xix + 452. 



(London : Macmillan and Co., Ltd., 1908.) Price («. 

 It is unnecessary to praise the charming series 10 

 which this book is the latest addition. Mr. Parker's 

 volume will appeal in an especial manner to Londoners, 

 who are within easy access of the delights of which 

 he writes; and it may be hoped that the descriptions 

 of .Surrey's natural beauties and historic interests will 

 encourage town dwellers to explore neighbouring 

 counties for themselves. Mr. Parker has many useful 

 hints to students of nature as to the favourite habitats 

 of special plants and animals; and the sportsman, too, 

 will find some guidance of the kind he desires. The 

 sketches make it possible to appreciate the beauty_ of 

 the highways and byways in Surrey without visiting 

 them. 



