>48 



NATURE 



[October 31, 1912 



part in the more elementary stages of physics 

 similar to that which his well-known text-book has 

 done and continues to do in the later stages. 



Considering the amount of matter involved, it 

 is, perhaps, not surprising that the treatment 

 seems somewhat disjointed in the abrupt passages 

 from one section to the next. This is most 

 marked in the part on mechanics, which, however, 

 the author tells us, is only included on account 

 of the requirements in the main part of the book. 

 As a consequence, it is doubtful whether it would 

 be possible for a student to master the subject 

 by unaided reading; but, after all, that should 

 not be the purpose of a text-book. It should be 

 regarded as an aid to oral instruction. The 

 printing and diagrams are good and in many 

 respects the book is unique. 



(6) The fifth edition of Prof. Riecke's excellent 

 text-book has been improved and extended in 

 various ways. On one hand we have more com- 

 plete treatment of such subjects as radio-activity 

 and the conduction of electricity in gases, which 

 in the earlier editions were only touched upon. 

 On the other hand, there is the introduction of 

 new matter, comprising liquid crystals, Brownian 

 movements and the work of Michelson and of 

 Nernst. Like most of the German standard text- 

 books, this one is much more complete than corre- 

 SDondin<i- works in English, and it is greatly to 

 the credit of the authors that they spare no trouble 

 to bring the new editions of their books really 

 up-to-date. The printing and diagrams are \ ery 

 much above the average. Surely there could be 

 no better testimony of the worth of a scientific 

 book than that it is now in its fifth edition. 



(7) This book is quite a novelty. It consists 

 of nearly fourteen hundred diagrams — curves, 

 photographs, &c. — representing physical facts, 

 with short explanations of each collected at the end 

 of the book. Although, of course, it could not be 

 regarded as a substitute for an ordinary text-book, 

 it might well be a useful companion to the latter. 

 The arrangements of the diagrams is occasionally 

 somewhat inelegant, doubtless due to space con- 

 siderations, but they are, as a general rule, well 

 printed, and in every case what is represented is 

 clearly indicated. 



OUR BOOKSHELF. 



Modern Problems. By Sir Oliver Lodge, F.R.S. 



Pp. vii + 320. (London: Methuen and Co., 



Ltd., igi2.) Price 5.?. net. 

 A COLLECTION' of essavs which have for the most 

 part appeared before as articles or addresses, but 

 which were well worth gathering together and 

 publishing in more permanent form. The subjects 

 dealt with are chiefly social and philosophic — the 

 NO. 2244, VOL. 90] 



function of money, universal arbitration and the 

 irrationality of war, Poor Law reform, the 

 position of woman, the drink question, the nature 

 of time, the philosophy of Bergson — these will 

 indicate the wide scope of the book. All the 

 chapters are characterised by the admirably lucid 

 yet thorough exposition which Sir Oliver Lodge's 

 writings alwavs present; and the conclusions, 

 definite though cool and undogmatic, are full of 

 that ripe wisdom which only a wide human out- 

 look on life can give. 



From the scientific point of view, one of the 

 most interesting chapters is that on the smoke 

 nuisance, in which the author deals with the prob- 

 lems of combustion, and advocates the use of gas 

 fires and the suppression of crude combustion of 

 coal in towns. .4s to river and sea mists, and 

 fogs of non-avoidable kind. Sir Oliver suggests 

 electrification of the atmosphere on a large scale, 

 a plan which he has brought within measurable 

 distance of application. This matter is again 

 touched on in the chapter " .Squandering a 

 Surplus." No one can tell for certain what would 

 happen by this atmospheric electrification, but it 

 is possible and even probable that the results 

 might be of incalculable benefit; crops might be 

 assisted, rain produced, fog dissipated. When we 

 think of the tremendous harmfulness of fog, 

 financially and to the health of our citizens, it 

 seems obvious that the prospect of a cure of this 

 evil would justify a large national grant for 

 expenditure on trials in a large way. It is to be 

 hoped something of the sort mav vet be done. 



J. A. H. 



Chrysanthemums. By T. Stevenson. With 

 Chapters by C. H. Payne and C. E. Shea. Pp. 

 xiv+ii2. (London and Edinburgh : T. C. and 

 E. C. Jack, n.d.) Price is. 6d. net. 

 This is the latest addition to the admirable 

 " Present-Day Gardening " series, edited by Mr. 

 R. Hooper Pearson. It appears at an appropriate 

 time and will interest as well as instruct all who 

 are concerned with the culture of chrysanthemums, 

 whether for pleasure or profit. Though there is 

 no reference to the existence of the plant in 

 English gardens before 1764, it was mentioned 

 by Confucius five hundred years or so before the 

 commencement of our era. In the first third of 

 the nineteenth century, about fift}' varieties were 

 known to English growers; and no attempt had 

 been made to raise new varieties from seed. The 

 first novelties obtained from seeds were exhibited 

 by Mr. I. Wheeler, of Oxford, in 1832; and since 

 then hundreds of beautiful forms have been pro- 

 duced. In the volume before us, details are given 

 as to the procedure in raising seedlings and 

 creating new varieties ; and also particulars as to 

 the care of chrysanthemums in all stages of their 

 growth. The book will delight and assist all 

 growers of the plant, and is a valuable addition 

 to a series which should be known to all lovers 

 of gardening. There are eight coloured plates 

 showing typical flowers, and lists of varieties for 

 cultivation as decorative plants or flowers. 



