KN()\VLi:nr,i:. 



Feiiruarv, 1912. 



A ILiiulbook of Oriitinic Ainilysix. - Bv II. 1 halH1-,i< 



Clarki;, H.Sc. (Loud.), A.I.C. J(i4 |ugcs. 23 illustrations. 



7J-in. X5iii. 



(lidwin Arnold. Price 5/- net.) 



This small book should meet the long-felt want of a concise 

 text book upon organic (|ualitative analysis. It deals system- 

 atically with the identification of different organic radicles, 

 and organic compounds, anil gives a new and most useful 

 classified table of the physical properties of the more 

 common substances. This table will obviate the necessity 

 of freciucnt references to chemical dictionaries or larger 

 te.Nt books; in future editions it might with advantage be 

 amplified so as to include some of the important com- 

 pounds omitted. The section of these tables dealing with the 

 identification of different classes of dyestuffs will pro\e 

 p.irticularly valuable. 



The latter half of the book, which deals with the quiintil- 

 ative analysis and determination of the physical properties 

 of organic compounds, does not present the same novel 

 features as the first part, though it describes clearly, and at 

 sufficient length, the ditTerent methods of estimation. Kven 

 processes not ordinarily found in elementary handbooks, such 

 as, for example, Wijs' method of determining the halogen 

 absorption of unsaturated bodies, are here fully described. 



The book is well printed, and illustrated with diagrams 

 where necessary, and we can thoroughly recommend it as a 

 laboratory companion both to the student and advanced 

 worker in organic chemistry. 



C. A. M. 



CRYSTALLOGKAl'HY. 



Crystallography and Practical Crystal Measurement. — 

 By A. E. H.TUTTON. D.Sc, M.A. (OxonI, F.R.S., A.R.C. Sc. 



Vice-President of the Mincralogical Society. 946 pages. 



720 figures in the text and 3 plates. 9-in.X6-in. 



(Macmillan & Co. Price 30/- net.) 



The subject of crystallography being one which claims so 

 few ardent students in this country, it is perhaps not to be 

 wondered at that English authors and publishers have for some 

 years refrained from any large and exhaustive publication on 

 the subject. The fine work which has now been published 

 will be heartily welcomed by all crystallographers and will 

 undoubtedly rank as a standard work on the subject. 



As its title imphes, the book is intended as a guide to the 

 practical measurement of crystals rather than as a complete 

 text-book of crystallography. The author has made every 

 effort to remove all grounds for the assertion, so frequently 

 m.ide, that crystallography can only bo studied by mathe- 

 maticians. .Accordingly, while pointing out the real need of a 

 knowledge of higher mathematics for tlie thorough mastering 

 of crystallography, the author has reduced the computation 

 of the physical constants of crystals to the application of 

 some four pages of simple formulae, all geometrical or 

 analytical proofs of these formulae being omitted. 



The first part of the book is devoted to the morphological 

 characters of crystals. A few pages on the nature of crystals 

 serve as an introduction to accurate instructions for the 

 growing and selection of crystals suitable for measurement. 

 The simplest types of goniometers are then described in great 

 detail, and in the fourth chapter the knowledge alreadv 

 obtained is shown to be sufficient to enable the reader to 

 measure completely a crystal of potassium sulphate. After 

 devoting three chapters to the conceptions of crystal axes, 

 face indices and zones, and to the stereographic projection, 

 and the few simple formulae mentioned above, the results 

 of the measurcnients Tuade in Chapter IV are worked out. 

 The simplification of the mathematics has. perhaps, boon 

 carried a little too far and strikes one as being somewhat 

 inconsistent. Thus, while elaborate pains arc taken to explain 

 the application of Napier's rules, the reader is left in entire 

 ignorance of the signification of the " zone indices," which 

 are obtained by cross-nmltiplying the indices of .any two faces 

 in the zone. The reader who has little knowledge of mathe- 



matics ni ly at first fail to appreciate Chapter IX, which is a 

 truly brilliant resume of the mathematical work on cr>-stal- 

 structure, ;ind will no doubt appeal more to advanced students. 



The seven crystal-systems are next studied, commencing 

 with the cubic system, as being the one re(|uiring the simplest 

 calculations, and leading gradually up to the more difficult 

 systems. Two chapters are devoted to each system, one deal- 

 ing with the elements of symmetry and possible forcns in the 

 various classes, the other giving examples of crystals measured 

 by the author, each one completely worked out. the results 

 being tabulated in the form adopted in publications of 

 crystallographic data. 



The methods employed for drawing crystals are clearly set 

 forth in Chapter XXV, again with the aid of as little mathe- 

 matics as possible, but calling attention to Penfield's excellent 

 methods based on the stereographic projection. Twinning 

 and planes of cleavage and gliding are dismissed in two short 

 chapters, and the first part of the book concludes with a 

 description of recent advances in goniometry. the determina- 

 tion of density, and a clear account of the theories of crystal- 

 structure put forward by Fedorov and by Pope and Barlow. 

 this last chapter being a most valuable contribution. 



The second part deals mainly with the optical properties of 

 crystals and no pains have been spared to make this part 

 thorough. The chapter reviewing recent ideas on the nature 

 of light .and the three succeeding chapters pave the way for 

 the study of the transmission of light through uniaxial and 

 biaxial crystals. The determinations of optical constants are 

 described in the same detailed manner as the measurements 

 in the first part. Two chapters on the crystallographic 

 microscope are full of useful suggestions and descriptions of 

 the most recent methods. The remaining three chapters are 

 occupied with thermal expansion, elasticity and hardness, with 

 a brief summary of the recent work on liquid crystals. 



Throughout the book the treatment is better suited to 

 chemical crystallography than to mineralogy. .X sufficier.t 

 supply of material of the highest degree of purity and of 

 perfect crystal development is postulated, and the mineralogist 

 may frequently find himself unable to attain the degree of 

 accuracy which the author has shown to be possible wiih 

 crystals grown under suitable conditions. This book, how- 

 ever, sets before all crystallographers an ideal at which to aim. 

 and it is to be hoped that its influence in this direction will be 

 widely felt. 



The fact which adds enormously to the value of the book is 

 that every branch of the subject which is treated at length is 

 one to our knowledge of which the author himself has 

 contributed very largely. Consequently, we have in this book 

 the results of years of experience in carrying out most 

 accurate and laborious measurements. The care and 

 accurate detail with which the book has been written yield 

 most eloquent testimony to the untiring patience and accuracy 

 which characterise all Dr. Tutton's work. 



The figures with which the book is lavishly illustrated are 

 most beautifully reproduced, and the publishers, as well as the 

 author, are to be heartily congratulated and thanked for so 

 valuable a publication. ... „ ^ 



MEDICINE. 

 The Art of Life — The Way to Health and longevity. — By 

 J. L. Chundr.-\, L.M.S. 240pages. Illustrated. 7.\-in.X 5-in. 

 (Calcutta University. Price 3 - net.) 

 This interesting little book is unique in many ways. The 

 author is clearly a man of very wide reading, and gives us 

 the combined wisdom of the East and West. Thus we find 

 ijuotations from the Hindu Scriptures and from the latest 

 .American medical journals on the same page, and while 

 ordinary medical prescriptions are given, we are also told 

 that "' Persons who have been given up to die are often restored 

 to perfect health in a few minutes by the hands of the Magnetic 

 Healer." Tlie author has written his book for the laity and 

 medical profession alike, but the inclusion among its " varied 

 and valued ingredients " of detailed medical prescriptions and 

 full descriptions of indolaceturia. cretinuria, and so on, would 



