November 25, 1897] 



NATURE 



75 



by a simple mechanical analogue, by means of which the 

 conception of absolute temperature is introduced. The 

 determination of specific heats, properties of gases, change 

 of state. Van der Waals's equation, and the critical point 

 are well treated, and an attempt is made to explain the 

 phenomena from the molecular standpoint, so far as this 

 can be done by general reasoning. The author's treat- 

 ment of thermodynamics, however, does not present any 

 striking divergence from the conventional standpoint 

 in which conservation of energy necessarily occupies a 

 prominent position. Of the chapters on electricity, 

 magnetism and light, we can only say that they appear 

 to form a concise and convenient introduction to the 

 elementary principles of the subject. 



As an introductory sketch of the outlines of natural 

 philosophy, the book may be unhesitatingly recom- 

 mended. The wide range of ground covered renders 

 the treatment somewhat encyclopaedic, but a notable 

 feature is the large amount of historical information with 

 which each chapter opens. This alone makes the volume 

 valuable as a work of reference. 



Another excellent feature is the large number of 

 examples on nearly every section. Many of these are 

 straightforward numerical calculations based on the 

 bookwork, nearly all of them illustrate some point of 

 physical interest. But it is a pity that the student after 

 reading the question sees the answer before him, instead 

 of having an opportunity to work it out for himself; 

 these answers would be much better placed at the end of 

 the book. 



Whether Herr Januschke has succeeded or not in 

 establishing the superiority of the " energetic " method, 

 there can be no doubt that he has produced a text-book 

 which will prove of great use to students, and still more 

 to teachers of physics. G. H. Bryan. 



THE FERTILITY OF THE LAND. 

 The Fertility of the Land. By Isaac P. Roberts. Pp. 

 xvii -I- 415. With forty-five illustrations. (New York : 

 The Macmillan Company. London : Macmillan and 

 Co., Ltd., 1897.) 



THE sub-title of this volume, "A summary sketch of 

 the relationship of farm-practice to the maintain- 

 ing and increasing of the productivity of the soil," 

 conveys a comprehensive idea of its scope. It belongs 

 to the Rural Science Series, and Mr. L. H. Bailey, who 

 contributes the preface, bestows upon the book a sort 

 of editorial benediction when he commits himself to the 

 statement, " It is the ripened judgment of the wisest 

 farmer whom I have known." The editor further re- 

 marks, 



" I confess that I have looked with some apprehension 

 upon the rapid diffusion of experimental science of recent 

 years, for there is danger that this knowledge may over- 

 shadow the importance of accustomed farm-practice, and 

 lead the farmer to demand specific rules for each per- 

 plexity, and to depend upon the Experiment Station and 

 the teacher for his farming." 



The fifteen chapters deal with the following subjects : 



(i) an inventory of the land ; (2) the evolution of the 



plough ; (3) tilling the land ; (4) conservation of moisture ; 



(5) irrigation and drainage ; (6) farm manures ; (7) 



NO. 1465, VOL. 57] 



manures produced by various animals ; (8) the waste of 

 manures ; (9) the care, preservation and application of 

 manures ; (10) nitrogen and nitrification ; (11) the phos- 

 phoric acid and potash supply ; (12) commercial fer- 

 tilisers ; (13) lime and various amendments ; (14) green 

 manures and fallows ; (15) rotations. The treatment of 

 the subject is thus seen to be fairly discursive, and the 

 omission of, for example, the second chapter on the 

 evolution of the plough would in no way have detracted 

 from the main object of the volume. It may be noted 

 in passing that the part of the implement which is 

 familiarly known in this country as the skim coulter is 

 designated the "jointer or skim plough" by the author; 

 we thmk the English name is preferable as being more 

 descriptive. Much valuable information is brought to- 

 gether in the volume in a convenient form, whilst mo^t 

 of the assertions made by the author, though they may 

 not always carry conviction, are suggestive in character 

 and calculated to stimulate useful trains of thought in 

 the student's mind. The chief defect of the volume is 

 that it ignores the epoch-making work in which Lawes 

 and Gilbert have been engaged for more than half a 

 century. Neither their names nor the name of Rotham- 

 sted are mentioned in the index, nor do we come 

 across any reference to them in the text. As the author, 

 we are told, "has had the advantage of much travel," 

 we can only suppose this omission is intentional. The 

 book, of course, suffers in consequence ; to give only 

 one instance, the author has missed entirely the admir- 

 able definitions of " fertility " and " condition " as applied 

 by Lawes to the soil, and as usefully adopted for prac- 

 tical purposes by English farmers. That the writer is 

 not altogether successful in his selection of authorities 

 is further apparent from the circumstance that he be- 

 trays no knowledge of the researches of Warington in 

 nitrification. There is evidence, however, of much 

 familiarity with continental work, and the title of the 

 thirteenth chapter, " lime and various amendments'^ has 

 an unmistakably French flavour. The book is well 

 printed and neatly turned out ; but the Englishman 

 who respects his mother-tongue will experience a shudder 

 at the strange spectacle presented by certain familiar 

 words spelt in " American." 



CRIME AND CRIMINALS. 

 Crime and Criminals. By J. Sanderson Christison, 

 M.D. Pp. 117.' (Chicago: The W. T. Keenen 

 Company, 1897.) 



DR. CHRISTISON has been attracted to a subject 

 full of difficult problems, but he makes no very 

 practical contribution to their solution. He is a student 

 in the school of Lombroso, and has been at some pains 

 to investigate the psychological aspects of the criminal 

 The cases he presents are, many of them, interesting 

 enough ; but beyond proving the fact that the types of 

 offenders are much the same all the world over, they 

 serve no particular purpose, and they are certainly not 

 sufficient to justify the main point of his book — that our 

 existing penal methods are a failure. He has been 

 helped to this conclusion, moreover, by the single 

 experience of the United States where, in his own 

 words, " crimes are now nearly five times as numerous 



