Febkuakv. 191: 



KN()\\I.i;i)(".l 



69 



seem to our Western iniuds a little undesirable if the laity are 

 reallv expected to read it. Moreover, the English is in places 

 a little obscure. .Among some excellent rules for the care of 

 infants we read: " Don't forget to put the child in the sun or 

 sunshade for two hours at least a day." 



Nevertheless, the book contains much sound, practical, useful 

 advice, particularly applicable to those resident in w.irm 

 countries, and e\ery page shows us that the author, if a little 

 over-credulous, has considered most carefully the problems of 

 existence, and knows how to express his meaning clearly, 

 tersely and in a very interesting style. 



Further Researches into Induced Cell-reproduction and 



Ciineer. By H. C. Ross. The McFadden Researches. 



63 pages. 5 plates. 9-in. X 5i-in. 



ijohn Murray. Price 3 6 net.) 

 The present volume contains a series of papers by Messrs. 

 H. C. and E. H. Ross and J. W. Cropper, on certain changes 

 which they have observed in red and white blood corpuscles, 

 when these are supported on a film of jelly and various 

 chemical substances are made to act upon them. The 

 researches here described are a continuation of those recorded 

 in a volume published a year previously, a review of which 

 appeared in "Knowledge" for March, 1911, and many of 

 the observations therein made apply with equal force to the 

 present editioTi. There can be no doubt as to the care and 

 accuracy of the observations recorded, and of the value of the 

 methods which the authors have introduced. Whether in all 

 particulars they are correct in the interpretation of their 

 results is a question upon which pathologists are still divided. 

 No one will, however, doubt that both volumes form a 

 valuable contribution to the phvsiologv and pathologv of the 

 blood. 



MINERALOGY. 



The World's Minerals.— By Leonard J. Spencer. M..A., 



I'.Cr .S. 212 pages. 61 illustrations. 8i-in. X 55-in. 



tW. & R. Chambers. Price 5/-.) 



The author of this book is an official of the Mineral Depart- 

 ment of the British Museum and is the editor of the 

 Mineralogical Maf^azine. 



In 1904 he translated from German, into English, the 

 beautiful work upon precious stones by Dr. Max Bauer of the 

 University of Marburg, and also m.ade certain additions to the 

 text. We believe that the English edition of this work is now 

 out of print. 



In the preface to "The World's Minerals" the author tells us 

 that the book deals with one hundred and sixteen of the more 

 simple minerals, which are illustrated by one hundred and 

 sixty-three figures in the coloured plates, and that mention 

 also is made of the various applications of minerals, their 

 importance as ores of metals as precious stones, and so on. 



We are sure that the information given of the various 

 minerals is in every way correct, especially considering the 

 position which the author has so long occupied and the work 

 which he bas previously done. We find, however, that in 

 some cases the descriptions are so meagre as to be somewhat 

 misleading. 



.As an example of what we refer to we may quote Spinel, 

 which is described as a red mineral occurring in the cubic 

 system, which when cut as. a gem somewhat resembles the 

 ruby in appearance, but the author does not tell us that it also. 

 in different specimens, is green, blue, brown and violet. 



We also cannot quite understand why such a mineral as 

 chrysoberyl. with its important gem-stone varieties, has been 

 omitted. 



On page 90 the author describes the fibrous variety of quartz 

 as catseye. and refers the reader to an illustration stated to be 

 made from a specimen from Ceylon. Now. the beautiful catseyes 

 of Ceylon are a variety of the mineral chrysoberyl. and they rank 

 among the most important precious stones, w-hilethe chatoyant 

 quartz is a stone of quite minor consideration, commercially, 

 and in every other respect, although it slightly resembles the 

 chrysoberyl catseye in general appearance. The writer does 



not explain this, nor is it apparent that he is aware of the 

 fact. 



The book will probably be welcome, for it is written in such 

 a clear manner that e\ery student will be easily able to under- 

 stand it. 



The coloured plates are very numerous and add consider- 

 ably to the value of the work. They have been prepared 

 under the supervision of Dr. Hans Lenk, Professor of 

 Mineralogy and (ieology in the University of Eriangen, and 

 many of the pictures represent actual specimens belonging to 

 the collection under his charge. 



Here and there we take exception to a shade of colour, but 

 this is probably due to the process of reproduction. 



In the early pages of the book the author gives an intro- 

 duction to the study of minerals which will be most helpful to 

 the student. 



Chapter 2 is devoted to " The Forms of Minerals," and we 

 notice here that crystals are classified under seven systems 

 and not six as is customary, and we rather wish the author 

 had given us his reason for doing so. 



The book has an excellent index, which appears to be 

 reliable. 



PHYSICS. 



Physical and Chemical Constants and some Mathematical 



Functions.— By G. W. C. Kaye and T. H. Laby. 



153 pages. 9ii-in.X6j-in. 



(Longmans, Green & Co. Price 4 6 net.) 



The authors have compiled a most useful book of reference. 

 It is remarkable how much is to be found in this thin book of 

 one hundred and fifty pages. One can find within all the 

 data which one is constantly requiring to look up during one's 

 work in the laboratory, except, of course, the less common 

 constants, which one could hardly expect to find even in 

 Landolt Bornstein and Meyerhoffer's '" PhysikalischChemische 

 Tabellen." For instance, one would find the boiling point of 

 pentane but for the melting point, which is somewhere below 

 — 200° C one would have to search in some original paper. 



The book is very concentrated, and as a reference book is 

 therefore, all the more useful. It commences with the units, 

 and passes on to astronomical data, then follows a very com- 

 plete set of data in the subjects of heat, sound, and light. 

 The section on radioactivity and gaseous ionisation is excellent 

 and gathers much valuable work together in a set of excellent 

 tables. The Chemistry section is necessarily rather curtailed, 

 but the chief properties of all the commoner chemical sub- 

 stances are to be found in two tables of the physical constants 

 of inorganic and organic substances. There is a short table 

 of solubilities in water of a few common substances, but a 

 complete solubility table requires a large book of its own. 



The mathematical tables at the end, though only occupying 

 eighteen pages, are those that are most generally needed and 

 are very conveniently arranged. .\ table of the exponential 

 c "* will be very useful to students of r.idioactivity. 



.\s far as one can judge, the tables are reliable and thoroughly 

 up-to-date, while the recently-formed international committee 

 for the yearly publication of physical and chemical constants 

 will help to make it the easier to keep the book abreast of the 

 times. 



The value of the book is enhanced by brief references to 

 books and original papers which have bearing on the various 

 subjects under consideration. 



The book is excellently got up and thoroughly suitable for 

 the laboratory. 



ZOOLOGY. 



Primitive Animals.— By Geoffrey Smith, M.A., Fellow 

 of New College, Oxford. 156pages. 25 figures. 6i-in.X4iJ-in. 

 (Cambridge University Press. Price 1/- net.) 

 It was a happy idea on the author's part to give this intro- 

 duction to the study of phylogeny a concrete and picturesque 

 basis in a series of " primitive animals " or old-fashioned 

 types, Uke Peripatus and Platypus, .\naspides and Amphioxus. 

 " Relics of a distant past, the features of which have been all 



