August 25, 1923] 



NA TURE 



277 



north as West Scotland, but hitherto " painted 

 pebbles " have only been found farther south. The 

 latter part of. the book is concerned with an account of 

 some open-air Neolithic stations. The whole is com- 

 pleted by the inclusion of a very full bibliography, 

 referring both to the archaeology and to the palseon- 

 tology. 



The authors are to be congratulated on their explora- 

 tions and on the publication — especially on having 

 managed to include so many and such excellent plates. 

 The area under discussion is of course restricted, but 

 it is exceedingly important that the results obtained 

 in various diggings should be carefully published, and 

 not, as is, alas, so often the case, be either not published 

 at all or merely noted briefly in some obscure review. 

 The finds described in the above work are preserved 

 in the museum at Basle. M. C. B. 



The Practical Applications of X-rays. By Dr. G. W. C. 

 Kaye. Pp. viii + 135. (London: Chapman and 

 Hall, Ltd., 1922.) I05-. 6d. net. 



This book is based largely on a course of Cantor 

 Lectures given by the author, and is primarily con- 

 cerned with the many practical applications to which 

 X-rays are put at the present time ; this term is, how- 

 ever, not meant to include their medical: applications. 



Rather more than one-half of the book is devoted to a 

 description of the methods of production of X-rays and 

 of their measurement ; such a liberal proportion of 

 space will generally be welcomed by those seeking to 

 apply X-rays for themselves. During the War, X-rays 

 were used successfully to detect flaws in aeroplane parts, 

 and the author shared very largely in this work, of which 

 some good illustrations are shown. The main industrial 

 application may perhaps be said to be in the examina- 

 tion of metal castings, and the recent technical develop- 

 ments, whereby X-rays of very short wave-length may 

 be obtained, should see a widening range of application 

 here. 



X-ray examination shows some very striking differ- 

 ences between ancient and modem pictures ; these 

 differences are mainly due to the pigments and primers 

 employed by the artists ; present-day pigments are not 

 nearly so opaque to X-rays as the metallic pigments 

 used by the earlier painters. Some illustrations from 

 the work of Heilbron will convey sufficiently well to the 

 expert the assistance he ma}^ expect from the radiologist 

 in detecting the work of the vandal. 



The volume contains in one appendix the two 

 memoranda which have been issued by the X-ray and 

 Radium Protection Committee on methods of safety, 

 and in a second appendix a useful list of definitions of 

 terms in common use in X-ray and electro-medical 

 literature. 



Principles and Practice of X-ray Technic for Diagnosis. 

 By Dr. John A. Metzger. Pp. 144. (London : H. 

 Kimpton, 1922.) 14s. net. 



The author's aim is " to put into the hands of the 

 student and operator a formula on which to base his 

 work in order that he may obtain better results and 

 thus be able to reach a more correct diagnostic inter- 

 pretation." 



We must confess to a failure in finding the " formula." 

 The book opens with a glossary of terms and this is 



NO. 2808, VOL. I 12] 



scarcely reassuring ; for radiography we read " same 

 as skiascopy," which is not defined ; X-rays are said to 

 be rays of unknown quantity ; tension is defined as the 

 tendency of electricity to overcome resistance. 



On the second page of the first chapter the author 

 discusses the use of gas and Coolidge tubes, but we 

 are left wondering at what is meant by the following 

 statement : " The difference between the tubes used 

 with the high-frequency machines and the induction 

 coil is one of the vacuum, and the additional cathode 

 of the former to care for the inverse, while the difference 

 between those for the induction coil and the transformer 

 is that of a heavier target construction and lower 

 vacuum of the one to care for the additional voltage 

 and absence of an inverse." 



The book is profusely illustrated, mainly in order to 

 show the various positions of the patient which the 

 author advises for different diagnostic purposes. Many 

 of these are quite unnecessary, and three of them are 

 duplicated in the text. 



A Text-book of Intermediate Physics. By H. Moore. 

 Pp. ix-i-824. (London: Methuen and Co., Ltd., 

 1923). 225'. 6d. net. 



This is a very complete text-book for intermediate 

 students in universities. It is well printed, has many 

 original illustrations, and is provided with an exception- 

 ally good index of thirty -nine pages. Block type is 

 used for the principal laws and conclusions, so that 

 revision of his work on the part of a student is facilitated. 

 The author has, however, unfortunately reproduced a 

 number of the mistakes and incomplete statements of 

 his predecessors. He confuses surface energy and 

 surface tension, and on p. 149 he speaks of the weight 

 of the liquid below the meniscus in a capillary tube 

 being supported by the surface tension. He devotes 

 more space than is desirable to old and discarded 

 methods, e.g. Laplace and Lavoisier's expansion 

 apparatus, p. 173, and specific heat apparatus, p. 218, 

 while no information is given as to how the expansion 

 coefficient of a gas is calculated from observations with 

 accurate apparatus, p. 191. On p. 254 the saturation 

 vapour pressure over a solid is incorrectly shown. The 

 part on light is good, but there seems no reason for 

 omitting old sight from the list of defects of the eye on 

 p. 458. There appears to be no mention of the magnetic 

 circuit, and the diagrams of dynamos on pp. 739 and 

 741 may account for the necessity of silence on the 

 subject. 



Abriss der Biologie der Tiere. Von Prof. Dr. Heinrich 

 Simroth. Vierte Auflage, durchgesehen und ver- 

 bessert von Prof. Dr. Friedrich Hempelmann. Teil 

 I. Entstehung und Weiterbildung der Tierwelt. 

 Beziehungen zur organischen Natur. (Sammlung 

 Goschen Nr. 131.) Pp. 147. (Berlin und Leipzig: 

 Walter de Gruyter und Co., 1923.) is. 



This is a revision of Simroth's " Sketch of the Biology 

 of Animals," and a very interesting little book it is. 

 We do not think that the text corresponds particularly 

 well with the sub-title, which might be translated 

 " Rise and Progress of the Animal Kingdom : Relations 

 to Organic Nature " ; and in the catalogue these are 

 the titles of two separate volumes. But that is a 

 trivial detail. The little book before us deals mainly 



