April 17, 1902] 



NA TURE 



557 



various problems of locomolive balancing is very inter- 

 esting, appearing to tlioroughly fulfil the conditions. 



Prof. Dalby has produced a book useful alike to the 

 mechanical engineer and the student. N. J. L. 



Guide to Italy. Pp. civ + 352 + 4. Price \os. net. 

 Guide lo the Western Mediterranean. Pp. xxvi + 23S. 



(London : Macmillan and Co., Ltd., 1901.) Price 9^-. 



net. 

 In adding one more series of guide-books to those 

 already in existence, the publishers have struck out in a 

 somewhat new line by making conciseness their most 

 important feature. The overworked professional man, 

 who has little time to read up lengthy descriptions, will 

 here find, condensed into a smaller compass than has 

 previously been done, the most important points to be 

 looked out for on his proposed journey. The authors of 

 these books have been remarkably successful in con- 

 densing so large an amount of information into them. 



The "Western Mediterranean " is divided into sections 

 dealing respectively with Lisbon, Andalusia, Morocco, 

 .Algeria, Malta, Naples, the Riviera, the Balearics, and 

 other ports and districts of interest. In "Italy" a different 

 and novel order has been adopted. The book opens with 

 articles on Italian life, art and architecture by " O. B." 

 and other well-known writers. Next comes a description 

 of routes only^ without lengthy descriptions of towns ; 

 lastly, the towns of Italy are described in alphabetical 

 order. The advantages of this method may not, perhaps, 

 impress the reader at a first glance, but as soon as he is 

 accustomed to the new order of things he will become 

 converted to the belief that the system effects a consider- 

 able saving of time and trouble and is most convenient. 

 Hotels are enumerated in a list by themselves ; in a 

 future edition the authors might with advantage make 

 an eftbrt to give fuller information under this head, 

 especially in reference to tariffs. There are also a few 

 minor points on which opinions may differ. Most 

 Italians know an " Inglese " fast enough and do not take 

 every foreigner for a Frenchman (p. xii.) ; in the vocabu- 

 lary (p. xvi.), " entrate " is a more familiar equivalent 

 for "come in" than "avanti" ; and if the authors of 

 "Italy" are really right as to the situation of Virgil's 

 tomb (p. 147), Neapolitan guides and cab-drivers have 

 been wrong for many years. The maps are excellent. 



Outlines of Electrochemistry. By H. C. Jones. Pp. vi -(- 

 106. (New York: The Electrical Review Publishing 

 Co., 1 901.) 

 This is an exceedingly interesting book. The title is, 

 perhaps, a little misleading. To our mind it would be 

 better to call it "Physical Foundations of Electro- 

 chemistry," or some similar title. There is an inclination 

 among \yriters of electrochemistry to treat the subject 

 entirely from the physical standpoint, hence many books 

 on the subject lack breadth of treatment. The present 

 book, as the author explains in the preface, is a re- 

 publication of papers which originally appeared in the 

 Electrical Review • New York). 



Chapter i. deals with osmotic pressure in a very clear 

 and lucid manner. Chapter iv., on the "newer theories 

 of electrolysis," is very ably written, and here Mr. Jones, 

 in explaining the theory of the electrolysis of water 

 containing acids, alkalis or salts in solution, adopts the 

 theory of Le Blanc, which looks upon the electrolysis of 

 water as being a primary and not a secondary reaction. 

 Most writers explain the electrolysis of water as being 

 of a secondary nature, due to the presence of the acid or 

 base in solution. According to Le Blanc, it is entirely a 

 question of the decomposition value of the water, and of 

 the salts, acids or bases in solution. In an aqueous solu- 

 tion of an acid, for example, it is simply a question 

 whether the ions of the acid or those of the water will the 



NO. 1694, VOL. 65] 



more readily give up their electrical charges, it being- 

 assumed that pure water is slightly ionised. 



Chapter vi., which is divided into two parts, deals with 

 the "conductivity of solutions," and a very interesting 

 lecture experiment, due to Noyes and Blanchard, for 

 showing the different conducting powers of various 

 electrolytes, is described. A good deal of attention is 

 devoted to the dissociating power of different solvents, 

 especial stress being laid upon the dissociation of 

 electrolytes in alcohol. Mr. Jones does not, however, 

 refer to the fact that certain inorganic salts are con- 

 siderably ionised when dissolved in pyridine. In this 

 connection it is interesting to notice that quite recently 

 Kahlenburg has succeeded in depositing lithium in the 

 metallic form, from the solution of its chloride in 

 pyridine. 



Mr. Jones is to be congratulated upon having presented 

 us with a very readable and scientifically written account 

 of the foundations of electrochemistry. We notice that the 

 author is engaged upon a work on physical chemistry, 

 the production of which we await with interest. 



F. M. P. 



Outlines of Botany. By R. G. Leavitt. Pp.272. (New 



York : American Book Company.) 

 This book has been compiled for use in high schools 

 and is based on Asa Gray's " Lessons in Botany," an 

 abridgment of his well-known standard work on plant 

 morphology. The author points out that he is not in 

 agreement with the strong ecological bias developed in so 

 many rece;it American text-books, and that he has 

 endeavoured rather to develop the study of structure and 

 form, and also to emphasise the physiological factors 

 which control plant life. This view will be endorsed by 

 many botanists. 



The method adopted is to suggest a series of practical 

 studies, each being followed by an elaborated theoretical 

 discussion. The principle involved of setting the student 

 to learn by direct observation depends firstly on the 

 student and secondly on appropriate treatment of the 

 subject. For advanced students such a course might be 

 admirable. But for students at high schools there is 

 neither the requisite time nor training required for such 

 investigations ; for these introductory lectures are abso- 

 lutely necessary. Then again, as regards his treatment 

 of the subject, one must entirely differ from the author. 

 The first chapter, dealing with seeds and seedlings, will 

 illustrate the objections to be raised. Beginning with 

 the gross features of the castor bean, lupin and maize, 

 the author next proposes a series of physiological 

 exercises — e.g. the nature and location of food reserves ; 

 absorption of oxygen, production of carbon dioxide and 

 heat evoh ed in germination ; geotropism and develop- 

 ment of chlorophyll. He then returns to morphology to 

 give a brief summary of special morphological features. 

 It will be observed that on the one hand the training to 

 be gained by a well-balanced and varied series of 

 anatomical exercises seems to have been overlooked, for 

 the castor bean does not offer a favourable object for a 

 first investigation, and at least eight or ten seeds should 

 be e.xamined. On the other hand, the physiology is too 

 varied. What teacher with practical experience does 

 not know the many difficulties and pitfalls which attend 

 even simple experiments? What success may be 

 expected for a young and inexperienced investigator who 

 attempts these broadly-extending exercises, with the help 

 of descriptions which are often extremely vague? 

 Throughout the chapters dealing with the flowering 

 plant there is the same paucity of development and want 

 of judgment in choosing anatomical exercises. The 

 book contains a cryptogamic course which is somewhat 

 superficial, and closes with two unsatisfactory chapters 

 on anatomy and physiology. 



