588 



NA TURE 



[August 27, 1908 



Iiiijher importance to smelters than the alloys proper, 

 and have been shown to obey the same laws when 

 they are fused and allowed to cool. 



The remainder of the book is devoted to the prac- 

 tical microscopy of metals and to an excellent and 

 jufficiently full description of the iron-carbon alloys. 

 The section is entitled " The Special Metallography 

 uf Iron and its Alloys," but no mention is made of 

 any alloy of iron except those with carbon, so that 

 for information as to all the special steels, which 

 are now of so much interest, the reader must wait for 

 another edition or another book. 



Enough has been said to show that the standard 

 work on metallography is yet to be written, but that 

 students will find Dr. Goerens's book admirable as 

 affording them a glimpse of the methods of investi- 

 gating metals and alloys. T. K. R. 



ELECTRO-rHERAPEUTICS. 

 Rontgcn Rays and Electro-therapeutics, with 



Chapters on Ractiiim and Phototherapy. By Dr. 



M. K. Kassabian. Lippincott's New Medical 



Series. Pp. 545. (Philadelphia and London : J. B. 



Lippincott Co., n.d.) Price 155. net. 

 V\/ITHIN the last ten years the study of electro- 

 » * therapeutics has rapidly grown, and, indeed, 

 the progress has been so great that it is almost im- 

 possible for any author to record the constant ad- 

 vances published from day to day. Many valuable 

 and important works have been published upon this 

 subject, and when stating this, Dr. Kassabian says 

 he wishes to present to his readers, clearly and con- 

 cisely, the more important facts pertaining to electro- 

 therapeutics and Rontgen ravs. 



'fhe book begins with a general introduction, and 

 considers the use of electricity in the medical curri- 

 culum. The following chapters are devoted to the 

 nature and properties of magnetism and electricity, 

 to different methods of producinsr electrical energy, 

 and it should be said the apparatus required for the 

 different forms have been verv fully entered into. The 

 next part of the work is devoted to pathological con- 

 ditions in general diseases and special departments. 



High frequency and, above all, as the title indicates, 

 Rontgen rays occupy a very large part of the book, 

 and the technique has been very carefully gone into. 

 Though treating of this subject generally, the annli. 

 cation of X-rays for diagnosis and treatment is fully 

 described, and three chapters are devoted to the study 

 of radium and photothcrapv. 



It will be seen from the very large number of sub- 

 jects introduced that it must be a very difficult thing 

 for any author to do justice to all in one volume. 

 It can be said, however, that any student of electro- 

 therapeutics carefully reading this book will find in 

 it a valuable aid, and any practitioner desirous of 

 obtaining an excellent general view of the subject will 

 do well to obtain a copy. There can be no doubt 

 whatever that the scope of the work has been care- 

 fully thought out, the descriptions and instructions are 

 clear and concise, and Dr. Kassabian deserves to be 

 congratulated heartily upon the general result. In 

 NO. 2026, VOL. 78] 



addition to the printed matter, there are no fewer 

 than 245 illustrations, many of them of great value, 

 and all of considerable service to the student. 



We have hinted in the above statement that the 

 subject is so vast that it is difiicult to do justice to 

 every department, and the author seems to be con- 

 scious of this, because he admits that the space is 

 all too brief for the study of phototherapy. The same 

 might be said of the attention paid to the physiological 

 effects of high-frequency currents. All the same. Dr. 

 Kassabian has exercised a wise discretion, 'because in 

 some parts of the book, such as the dosage of X-rays 

 — a vexed question, and yet one of vital importance 

 to the profession — he has given an excellent risum^ 

 of what has been done. 



Now and again the author might confuse a begin, 

 ner for want of a slight explanation ; for example, at 

 one time he points out (p. 44S) that the X-rays may 

 produce pigmentation of the skin, and, again, he 

 quotes the case of a brunette losing pigmentation by 

 the same agent. 



The index, although excellent, might be improved. 

 For example, " hypertrichosis " and " naevus " will 

 not be found under the initial letter of each word, but 

 under " X-raj's " in these affections. Other examples 

 might be quoted. 



OUR BOOK SHELF. 



On the Plantation, Cultivation and Curing of Pari\ 

 India-rubber (Hevea brasilicnsis), with an Account 

 of its Introduction from the West to the Eastern 

 Tropics. By H. A. Wickham. Pp. iv-l-78. 

 (London : Kegan Paul, Trench, Triibner and Co., 

 Ltd., 190S.) Price 35. 6d. net. 

 Mr. H. a. WiCKH.'VM re-tells the interesting story of 

 the successful effort of the Government of India with 

 the aid of the Royal Gardens, Kew, to introduce the 

 ParA rubber tree (Hevea brasilicnsis) from Brazil to 

 the eastern tropics. Though the tale, at least in 

 outline, is fairly familiar, it is one that bears repeat- 

 ing, and as told by Mr. Wickham will, in spite of a 

 certain rugga-dness of style, be read with interest, 

 since it has the advantage of being from the pen of 

 one who can say with truth of the history he relates, 

 pars magna fui. 



The passages in which Mr. Wickham strives to 

 impress on his readers his experience that the Pari"* 

 rubber tree is properly a denizen of the immense 

 forest-clad plains which occupy the areas between the 

 great rivers of the Amazon system will attract atten- 

 tion. These plains are considerably more elevated 

 than the flat ground which skirts the banks of the 

 actual rivers, and is periodically inundated when the 

 rivers rise. The tree does, indeed, occur on these 

 low-lying tracts, but in Mr. Wickham's experience it 

 does not thrive so well on these flooded levels as on 

 the somewhat higher plateaux that abut upon them. 

 The question is of interest because of the practical 

 bearing it may have on the treatment of Hevea 

 brasilicnsis as a cultivated tree. 



The discussion of the methods that, in the opinion 

 of Mr. Wickham, are most suitable for the cultivation 

 of the tree and the treatment of its late.x will also 

 be read with interest by those engaged in both occupa- 

 tions. The literature of the subject is already exten- 

 sive, and mucli of it is of high quality. But what 

 Mr. Wickham has to say will receive the attention of 

 those practically interested in Hevea as coming from 



