June 22, 1905] 



NA TURE 



171 



iii. to V. the theory for moving charges, vector 

 analysis being used throughout. The remaining 

 chapters deal with radio-activity, rotating charges, 

 radiation from electrons, the Zeeman effect, the 

 theory of Rontgen rays, aberration, and dispersion. 



The mathematical theory of the properties of elec- 

 trons appears to be well and clearly dealt with on the 

 whole, and the author has managed to compress a 

 great deal of information into a small space. English 

 readers will probably feel that sufficient credit is not 

 given to some English physicists to whom the 

 initiation of the whole theory is really due. The parts 

 of the book dealing with experimental facts and the 

 theory of things outside the electromagnetic theory 

 are rather superficial and sometimes erroneous. For 

 example, it is stated that the radio-activity of radiuiji 

 emanation diminishes very rapidly with rising 

 temperature, and that this can be deduced thermo- 

 dynamically from the large amount of energy evolved. 

 This glaring error shows conclusively that the author's 

 acquaintance Vi'ith the literature of radio-activity is of 

 the slightest. The book will no doubt be welcomed 

 by many anxious to learn about the new views on 

 inertia and matter, and to such it should prove useful. 



(2) Dr. H. Starke's book on experimental electricity 

 and magnetism contains a very up-to-date and excel- 

 lent elementary account of the subject. The explan- 

 ations of many of the experiments described seem 

 scarcely full enough to enable students actually to 

 work from them, but it is evidently not intended that 

 they should do so without further help. Many good 

 diagrams of modern forms of apparatus are given. 



(3) Dr. F. Bremer's book on physics for the upper 

 classes in schools is a rather bad type of school text- 

 book in which it is sought to make things suitable 

 for school children by giving very short and scrappy 

 accounts of everything. It looks like a book which 

 might be useful to a student with a very good memory 

 in cramming for an elementary examination in 

 physics. He might get through the examination, but 

 he would have learnt nothing worth knowing. 



Harold A. Wilson. 



.4 BOTANIST'S RECREATIONS ON THE 

 RIVIERA. 

 Strcifzii^c an der Riviera. By Eduard Strasburger. 

 Revised edition, with 87 coloured illustrations by 

 Louise Reusch. Pp. xxvi-l-4So. (Jena: Gustav 

 Fischer, 1904.) Price 10 marks. 

 'T^HE Riviera has of recent jears become regarded 

 as the playground of wealthy people whose only 

 idea of enjoyment consists in spending hours in the 

 unhealthy atmosphere of the casino at Monte Carlo, 

 raising dust with a motor-car, dining at separate tables, 

 or sitting in an hotel lounge. But such people see 

 nothing of the real Riviera, with its wealth of wild 

 tlowers, its charming rock villages perched on heights, 

 its olive, orange, and lemon groves, and its torrent 

 beds up which one scrambles from rock to rock, pass- 

 ing a succession of pretty pictures each prettier than 

 the previous one. On first reading Prof. Strasburger's 

 book, the reviewer formed the impression that the de- 

 scriptions were too prosaic and wanting in sunshine. 

 NO. i860, VOL. 72] 



It cannot be said that the author has succeeded in giv- 

 ing that warmth of colour to his account which charac- 

 terises Mr. Casev's charming book. But since that 

 impression was formed the present writer re-visited the 

 Riviera, and the feature which he most noticed was 

 how exactly every minute detail tallied with Prof. 

 Strasburger's descriptions. The information contained 

 in this book is just what is wanted to make a visit to 

 the " Cote d'.'^zur " both enjoyable and instructive. 



A large proportion of the text is taken up with his- 

 torical accounts of the various cultivated plants and 

 trees growing in the district. The most characteristic 

 vegetation of the lower valleys — the vine, orange, 

 lemon, olive, fig, cypress, and palm — is largely the re- 

 sult of "alien immigration." Before the hillsides 

 were carefully terraced and cultivated they were over- 

 grown with small scrub or " maquis " (Italian 

 " macchia ") consisting of pines, rosemary, myrtle, 

 tree heath, three species of cistus, mastic, juniper, 

 the characteristic spiked lavender (Lavandula 

 stoechas), the remarkable spiny euphorbia (E. spinosa), 

 and a number of other plants too numerous to mention. 

 The aromatic perfume of many of these plants is one 

 of the most salient features of the "maquis." In 

 Prof. Strasburger's description of this characteristic 

 undergrowth, the word " Duft " (perfume) occurs over 

 and over again. It is only after walking through such 

 vegetation that one realises that this very repetition 

 makes the description all the more accurate and real- 

 istic, and readers of the book will do well to bear in 

 mind the fact that each occurrence of the word usually 

 refers to a different scent. Prof. Strasburger's descrip- 

 tions of the " maquis " mostly refer to Antibes, where a 

 considerable area of this primitive vegetation still re- 

 mains untouched. In many places along the coast 

 the " maquis " is being rapidly cut down to make 

 room for unlovely vineyards, and the face of the 

 country is being made less beautiful. 



Considerable space is devoted to a description of the 

 gardens at La Mortola, and the scent manufactories at 

 Grasse also occupy many pages. In reading these 

 descriptions one cannot help regarding the author 

 somewhat in the light of a walking encyclopaedia. He 

 gives long digressions on the manufacture of chemical 

 perfumes in connection with Grasse, and he makes his 

 account of Sir Thomas Hanbury's garden the oppor- 

 tunity for giving much historical information about 

 many economic plants such as the tea, coffee, and 

 cocoa plants the sugar-cane — and, thence, the intro- 

 duction of beet-sugar, the ebony and the camphor tree 

 — which can hardly be regarded as the characteristic 

 vegetation of the district. On the other hand, several 

 interesting features are mentioned which a casual 

 visitor might overlook. The characteristic flora of 

 Hyferes and the comparative absence of dust in the 

 Esterel mountains are associated with the remarkable 

 difference of geological formation as compared with 

 the more frequented and fashionable but dustier winter 

 stations in the limestone districts. The nightly con- 

 cert of green frogs to which the author alludes is a 

 sound which brings the Riviera vividly back to every- 

 one who has heard it. 



On the whole, Prof. Strasburger seems to have de- 

 voted most of his attention to studying the plants 



