492 



KNOWLEDGE. 



Deckmber. 1910. 



bibliography is given, and from which many interesting 

 extracts have been incorporated in the text. AW recorded 

 mineral and medicinal waters within the county have been 

 investigated and many new analyses made, with the result 

 that only three occurrences can be classed as true mineral 

 waters. These owe their small medicinal properties to the 

 presence in them of magnesium sulphate. This salt occurs to 

 the extent of 197"3 parts per 100.000 in the water of the 

 Hockley Spa \\"ell. These waters have little or no medicinal 

 value, and the wonderful cures reported to have been effected 

 by them were as much due to faith as to a period of simple 

 and orderly living on the part of the patients whilst taking the 

 waters. Mr. W. H. Dalton points out that the great majority 

 of the springs occur within the area of the London Clay. 

 Their waters are doubtless derived either from sandy seams 

 in that formation, or from its contact with superficial gravels, 

 the mineral constituents being obtained entirely from the clay. 

 The authors are to be congratulated on having presented an 

 exhaustive account of an interesting subject — a model of the 

 kind of investigation which should be carried out under the 

 auspices of a local scientific society. 



Extinct Monsters and Creatures of Other Days. — By the 



Rev. H. \. Hutchinson. B..^.. F.K.G.S. J29 pages. 55 plates. 



113 figures in the text. 6-in. X 9-in. 



(Chapman lS: Hall. Price 10 6 net.) 



In this volume there have been combined together two old 

 and tried friends. " Extinct Monsters " and " Creatures of other 

 days." These books by the Rev. H. X. Hutchinson are so 

 well known to all who have studied geology, that it is only 

 necessarj- to point out the changes that have been made. 

 Some chapters from the second book on fossil fish and 

 crocodiles, and the chapter on " Relics of the Pleistocene 

 Period." have been omitted and a few of the creatures from 

 " Extinct Monsters." New photographs of .Anomodonts, sent 

 by Professor .-Vmalitzky. ha%e been added. Dinosaurs come in 

 for more attention, the elephant's ancestors are considered, 

 and the great birds and sloths from South .America. The 

 style in which the book is written and the striking illustrations 

 make it eminently suitable for a Christmas gift to any boy or 

 girl who has a taste for natural history. 



MEDICINE. 



Tlie Brain and \'oice in Speech and Son^ (Harper's 



Library of Living Thought). — By F. W. MoTT, F.R.S., M.D., 



F.R.C.P. 112 pages. 18 illustrations. 7-in. X4i-in. 



(Harper & Brothers. Price, cloth 2 6 net : leather 3 6 net.) 



There is always a peculiar pleasure to be derived from the 

 study of a work written by one who has a really first-hand 

 knowledge of his subject — a pleasure which we have experienced 

 at almost every page of the book now before us. Dr. ^Iott is one 

 of the greatest authorities on the structure and function of the 

 brain, and when he tells us of the cerebral and psychic mechan- 

 isms of the voice and speech we know that we are getting the 

 very best information obtainable, and are getting it first-hand. 



The early chapters are de\oted to a description of the 

 Anatomical Structure and Mechanical Action of the Vocal 

 Instrument. This is a very difficult matter to make clear with- 

 out the introduction of technical terms, but here also we 

 consider that the author has succeeded well. The book is 

 illustrated by half-tone blocks from careful and for the most 

 part original drawings, and is written in excellent style. It is 

 one of a series of dainty little books published by Messrs. 

 Harper, and should prove of especial value to singers and 

 public speakers, as well as to teachers of voice production. 

 To all interested in the study of the physiological and 

 psychical processes on which their being depends we cordially 

 recommend it. 



Tlie Mental Symptoms of Brain Disease. — By Bernard 

 Hollander, M.D. 237 pages. 7i-in. X 5-in. 



(Rebman. Price 6 - net.) 



Much valuable information regarding the function of the 

 different parts of the brain has, as the author points out, been 



derived from experiments on animals. But with regard to the 

 higher mental processes, the intellect and the emotions, such 

 experiments are. for obvious reasons, practically useless. Vet 

 it is these very processes that are deranged in that most 

 terrible of all diseases — insanity. Little wonder, then, that 

 until quite recently very little was known of the pathology and 

 treatment of mental disease. But now. thanks to such works 

 as that before us, our knowledge is rapidly increasing. The 

 present volume contains relatively few original observations, 

 but is mainly a collaboration from the original papers, in many 

 different languages, of cases in which serious mental symptoms 

 have been found, at operation or post mortem, associated with 

 definite organic changes in the brain. The collection and 

 classification of these cases represents an almost infinite 

 amount of careful research, and the conclusions which the 

 author justly draws from . them are extremely striking. The 

 whole work forms an important contribution to the study of 

 this most difficult subject. In it the physical origin of insanity 

 is demonstrated, and it is further shown that the different 

 types of mental disease are frequently associated with changes 

 in definite brain areas. The many examples cited, in which 

 insanity has been cured by surgical operation, form perhaps 

 the most convincing argument for the correctness of the 

 author's conclusions. 



PHVSICS. 



.4 Te.xt-Book of Physics.— By H. E. Hurst. M.A., B.Sc. 

 and R. T. L.\TTEY. M..-\. 63S + vi. pages. 9-in. x 6-in. 



(Constable & Co. Price 8 6 net.) 



Teachers of Physics will welcome this book. It supplies 

 exactly what is wanted for students who are working at the 

 preliminary scientific course required by the University of 

 Oxford of all who desire to take honours in Natural 

 Science ; and it will be found equally suitable for .Army 

 candidates and Medical students, as well as for candidates for 

 scholarships in Mathematics, for whom a sound elementary 

 knowledge of Physics is essential. The mathematical treat- 

 ment is elementary, but very clear and adequate, and the 

 diagrams are excellent. In a subject which leaves little 

 scope for originality of treatment, the authors have succeeded 

 in reproducing the individual character of a class-room, 

 presided over by an experienced and thoughtful teacher. A 

 well-chosen collection of e.xamination questions follows each 

 chapter, and the book has an up-to-date appearance through- 

 out. -As an instance we may mention the simple diagram and 

 explanation of the prismatic field glass in the chapter on 

 Optical Instruments. .Altogether it is a book to be recom- 

 mended. 



E.xpernncntal Elasticity. — By G. F. C. Searle, M.A., 

 F.R.S. 1 87 + xvi. pages. 9-in.X6-in. 



(Cambridge University Press. Price 5 - net.) 



Old Cavendish Laboratory students will remember the 

 MS instructions which the mathematician unaccustomed to 

 practical work used to cling to as to a trusty pilot. Mr. 

 Searle's long experience as a demonstrator has made him 

 thoroughly familiar with the difficulties of the unpractical 

 wrangler as well as those of the unmathematical medical 

 student. To quote his own words, he has had " to discover 

 why ... a student obtains 537"86402 [no units mentioned] 

 for Young's modulus, by an experiment on a brass wire, 

 instead of 9'S6 X 10" dynes per square centimetre." Some of 

 the reasons for this kind of result are given, and are followed 

 by extremely valuable hints on practical work in Physics, which 

 all students (and teachers) would do well to read and take to 

 heart. This book contains first an account of the elementary 

 mathematical theory of elasticity, with a rather full discussion 

 of particular problems, followed by descriptions of a large 

 number of experiments requiring for the most part simple 

 apparatus. Each description is followed by a fully worked 

 out practical example, which may serve as a model for students 

 in the recording of their observations ; and the book deserves 

 a place in every Physics laboratory. It is to be hoped that 

 the half-promised volumes on other branches of Experimental 

 Physics will not be long in making their appearance. 



