532 



NATURE 



[January 14, 19 15 



thought or feeling sometimes remain uncertain 

 and obscure. For in sympathetic magic the most 

 obvious connection is not necessarily that which 

 actually led to the employment of a particular 

 object or substance. To take a single example. 

 Prof. Petrie compares the Egyptian series of 

 animal-claw amubts with a leopard's claw from 

 Central Africa (Leicester Museum), and he ex- 

 plains it as an amulet for protection from wild 

 beasts. This explanation at first sight commends 

 itself as not only reasonable but obvious. Yet 

 when we turn to Burton's "Central Africa" we 

 find that in Central Africa the "mganga" or 

 sorcerer might employ a leopard's claw for 

 curing disease. The spirit or ghost with which 

 the sick man was believed to be possessed could 

 by drumming and dancing be driven out of him 

 into a leopard's claw, and when this was hung 

 to a "devil's tree" the disease-spirit was laid. 

 It is true that the leopard's claw was not essential 

 to the process, for in its pl.ace a peculiar bead, a 

 nail, or even a rag could be used as the medium 

 for exorcising the disease. But the fact of its 

 employment for this purpose in Central Africa at 

 least suggests the possibility of some other ex- 

 planation of its use in ancient Egypt than the fear 

 of attack by wild beasts. In several other cases 

 the possibility also suggests itself that the original 

 reason for the use of an object in primitive magic 

 may not have coincided with its later associa- 

 tions when it had survived as an amulet worn 

 on the person. 



We have merely referred to these points as 

 indicating the wide interest attaching to the 

 study of the subject. We cannot conclude with- 

 out a reference to the excellent photographic 

 plates, as well as to the chapters on the use of 

 amulets, in which not only the student and col- 

 lector, but also the general reader will find much 

 to interest him. L. W. K. 



OVR BOOKSHELF. 



Science and Religion. By Seven Men of Science. 

 Pp. 138. (London : W. A. Hammond, 1914.) 

 Price 15. net. 



In a week of November last, a series of seven 

 addresses upon the mutual relations of science 

 and religion were delivered by scientific men of 

 distinction at Browning Hall, Walworth Road, 

 London. The lecturers were Sir Oliver Lodge, 

 Prof. J. A. Fleming, Prof. W. B. Bottomley, 

 Prof. E. Hull, Dr. J. A. Harker, Prof. Sims 

 Woodhead, and Prof. Silvanus P. Thompson ; and 

 their remarks are now published in convenient 

 and cheap form in the little volume before us. 



It would be easy to discuss at great length many 

 of the statements made in these addresses, but no 

 useful purpose would be served by doing so here. 

 NO. 2359, VOL. 94] 



In the opening address Sir Oliver Lodge made the 

 definite announcement that he had conversed with 

 departed friends " as I could converse through a 

 telephone with anyone in this audience now " ; but 

 apparently it is not everyone who is capable of 

 receiving this evidence of survival of existence. 

 The only evidence upon which a man of science 

 cares to base a conclusion is that derived from his 

 own observations ; but in spiritual matters convic- 

 tion takes the place of phenomenal knowledge. 

 The poet and the metaphysician feel that certain 

 thoughts are true, and the ideas thus conceived 

 are to them as definite facts as any inferences de- 

 pending upon the use of the senses. Such feelings 

 do not admit of objective demonstration, and 

 cannot, therefore, be measured by the standards 

 of natural or physical science. They belong to 

 another world, which the describer of phenomena 

 may contemplate, but is usually unqualified to 

 enter. 



It is not to be expected, therefore, that these 

 addresses will bear the severe criticism to which 

 observations and theories are subjected in scien- 

 tific circles, and serious students of philosophy are 

 not likely to be impressed by most of the evidence 

 adduced of intelligent design in Nature. The 

 somewhat shallow treatment of this profound sub- 

 ject is, we suppose, explained by the popular audi- 

 ences to which the addresses were delivered. The 

 book is interesting as a declaration of men of 

 science to the reality of religious conviction ; but 

 it may be doubted whether any particular signi- 

 ficance should be attached to their views upon 

 questions outside the domain of objective truth in 

 which alone they can give authoritative testimony. 



A Study of the Circular-arc Bow Girder. By 



Prof. A. H. Gibson and E. G. Ritchie. Pp. 



viii + 80. (London: Constable and Co., Ltd., 

 1914.) Price los. 6d. net. 



This book treats of the difficult problem of girders 

 forming a circular arc in plan such as are often 

 used to support the balcony of a theatre. The 

 principles on which the general problem may be 

 solved are given in the early portion of the volume, 

 and are amplified from a paper read by Prof. 

 Gibson before the Royal Society of Edinburgh in 

 1912. Values of the end fixing moments and reac- 

 tions have been calculated for the more important 

 practical cases, and these values, together with 

 typical bending moment diagrams which are 

 given, will be found useful aids to the designer. 

 The authors have carried out experiments with a 

 view of checking the theoretical investigation, and 

 remarkable agreement is shown. Up to the ap- 

 pearance of this volume there has been no data 

 available for the torsional rigidity of beams of 

 ordinary commercial section, and part of the in- 

 vestigation undertaken by the authors has been 

 the experimental determination of the product CJ 

 {i.e., modulus of rigidity x equivalent polar 

 moment of inertia) for such sections. Mathemati- 

 cal calculations in such cases present insuperable 

 difficulties, and the experimental work given in the 

 book is an Interesting and valuable contribution 



