June 30, 192 1] 



NATURE 



549 



is a matter of great importance from national, 

 economic, and aesthetic points of view, yet this 

 phase of forest utility is only too often ignored. 

 In a short but interesting chapter the author has 

 succeeded in summarising the main facts and 

 focussing them in an admirably lucid manner. 



In the succeeding chapter the forest regions of 

 France and the important tree species are de- 

 scribed. An interesting review is given of the 

 area, topography, and prevailing climatic con- 

 ditions of France, and striking illustrations are 

 g-iven of the recent wonderful development of the 

 natural resources of the country in hydraulic 

 power. Further on are presented the forest statis- 

 tical data, which bring out many points of absorb- 

 ing interest. One striking fact is that the number 

 of small forest owners is incredibly large. The 

 small owner of less than 25 acres of forest is 

 gfreatly in the majority, but the proportion of sawn 

 timber to fuel wood in State-owned or technic- 

 ally managed forests is much more advantageous 

 than in those privately owned. 



The natural and artificial regeneration of forests, 

 as practised in France, is well worth the close 

 attention of students of sylviculture. An excellent 

 account is also given of the control by afforesta- 

 tion of mountain torrents and lowland floods, which 

 in the past have caused privation and ruin to 

 thousands of the population, and untold loss to 

 the nation. 



The author also gives a most interesting 

 account — historical, statistical, and technical — of 

 the wonderful forests of the Landes. The almost 

 magical transformation of a barren, fever-stricken 

 waste of something like two million acres into a 

 healthy and prosperous revenue-yielding territory, 

 to the enormous advantage of France and every 

 individual Frenchman, was a marvellous achieve- 

 ment. The State, as the author puts it, "blazed 

 the trail," the good lead was followed by the 

 "communes," and private effort did the rest. 

 Much useful information is given concerning 

 French Government regulations and working 

 plans, the features of French national forest ad- 

 ministration, and private forestry in France. 



An interesting account is given of the activities 

 of the Forest Engineers in France. The vital im- 

 portance of timber in modern warfare is shown 

 in many ways, and it is safe to conclude that 

 without the well-planned forests and timber re- 

 sources of France "the war might have been a 

 draw or a defeat instead of a victory." 



A number of interesting appendices are added 

 which deal with specific forestry subjects, includ- 

 ing an exhaustive list of French forestry litera- 

 ture, and there is a good index. The book is well 

 illustrated with photographs and diagrams. 

 NO. 2696, VOL. 107] 



Our Bookshelf. 



Official Statistics. By Prof. A. L. Bowley. 

 (The World of To-day.) Pp. 63. (London : 

 Humphrey Milford : Oxford University Press, 



I92I.) 25. 6d. 



A LITTLE book on statistics by so well-known an 

 authority as Prof. Bowley is sure of a welcome 

 from the educated public. In these times, when 

 copious reports are issued by many Government 

 departments, it is not only interesting, but also 

 necessary, to appreciate fully the significance and 

 limitations of official statistics. This is 

 admittedly difficult, and it is with the view of 

 steering the uninitiated through the mass of detail 

 which necessarily obscures the real value of statis- 

 tical information that Prof. Bowley has written 

 this little book. A brief account is given of the 

 more important reports and papers published 

 officially in recent years containing statistics of 

 genieral interest. The use of reports is illustrated 

 by collecting details scattered throughout such 

 a volume as the Report on Pauperism and 

 retabulating them so as to show how the various 

 tables are connected. In all cases exact refer- 

 ences have been given to the original documents. 

 The scope of the volume is well indicated by the 

 chapter headings, four in number : population ; 

 industry, trade, and prices ; income and wages ; 

 and social conditions. 



A Laboratory Manual of Organic Chemistry for 

 Medical Students. By Prof. M. Steel. Second 

 edition. Pp. xi -1-284. (New York: John 

 Wiley and Sons, Inc. ; London : Chapman and 

 Hall, Ltd., 1920.) 95. 6d. net. 

 A CHAPTER on colloids which contains some inter- 

 esting experiments forms the principal addition 

 to this edition. Many careless expressions 

 have been overlooked : " fused " copper sulphate 

 and " fused " calcium oxide are not common re- 

 agents, and "hydroscopic" (p. 32) appears in- 

 stead of ' ' hygroscopic. ' ' Moreover, some of the 

 directions for experiments do not seem to be based 

 on trials, e.g. the preparation of acetylene would 

 be dangerous if carried out as described on 

 pp. 19-20, for air could not be displaced from the 

 apparatus under the conditions named ; also the 

 directions g-iven for the preparation of colloidal 

 platinum on p. 220 do not seem correct — it would 

 be difficult to pass a current of 10 amperes through 

 distilled water by applying only 40 volts. 



Ammonia cmd the Nitrides: With Special Refer- 

 ence to their Synthesis. By Dr. E. B. Maxted. 

 Pp. viii-t-ii6. (London: j. and A. Churchill. 

 192 1.) 75. 6d. net. 



This small volume contains an account of labora- 

 tory investigations of the nitrides of the elements. 

 No mention is, however, made of the very im- 

 portant industrial applications of the results except 

 in the case of the Serpek process, which is not in 

 use in the form described by the author. 

 *• Deville," on p. 37, should be " Regnault." 



