September, 1906.] 



KNOWLEDGE & SCIENTIFIC NEWS. 



547 



specialist as author. Perhaps the chief objection to siib- 

 dividing the subject and attempting to make each part com- 

 plete in itself, is that there must be a large amount of overlap 

 or of omission, for photography is one, whether magnesium 

 light or daylight is used, and whether the print lie a post-card 

 or otherwise. Both these recent additions to one of Messrs. 

 Dawbarn and Ward's series, are by men of practical expe- 

 rience in the subjects they treat of, and may be safely accepted 

 as guides. The treatise on picture post-cards is divided into 

 two parts : first, the making of them, and second, the making 

 of money from them ; and both volumes deal with the busi- 

 ness or commercial side of the subject as well as the more 

 strictly photographic side. The authors have made a judicious 

 selection of subjects to treat fully, and have not omitted to 

 refer to alternate processes. 



PHYSICAL CHEMISTRY. 



Higher Mathematics for Students of Chemistry and Physics. 



J. W. Mellor {Longmans; 15s. net.)— The rapid growth of 

 phy.'^ical chemistry has taught the chemist that unless he is 

 equipped with a sound working knowledge of mathematics 

 he stands at a disadvantage so great that he is practically 

 excluded from a considerable region of his subject. The 

 man who desires to go behind mere experiment to the 

 general laws which enable results to be classified must ac- 

 quaint himself with mathematics, for it is onlj- in terms of 

 mathematical symbols that these relations can be concisely 

 expressed and deductions from them made. This book, 

 which now appears as a second and considerably enlarged 

 edition, is intended to provide such a selection from the 

 various departments of mathematics as may subserve the 

 needs of such a student. It is not for the mathematical 

 specialist, and consequently what the author considers 

 " tedious demonstrations " are sometimes avoided by merely 

 making reference to the " regular text-books." The aim 

 throughout is to make the student alive to the real meaning 

 of mathematical expressions by means of examples selected 

 from work with which he is otherwise familiar. 



Although it is probably the chemist who will he most at- 

 tracted, a great number of the problems are of a purely 

 physical nature. It is doubtful whether it was worth while 

 to cater for the physicist, who presumably will receive a 

 training in a more formal way; but, of course, many will 

 be glad of the assistance which the book affords. And to 

 them we would say that there is no branch of physics which 

 does not contribute to the examples here analysed. The 

 chemist would find it more useful if many of these problems 

 were not present. The book appears to be carefully edited ; 

 we have noticed only a few misprints. Rut in some places 

 the sentences might be made less ambiguous if re-written 

 diffiTcntly. 



SCHOLASTIC. 



A Guide to the Klectrlcal Examinations. I\ II. Taylor, 

 A.M.l.M.E. (Percival M;u-shall and Co., is. net, paper; 

 IS. 6d. net, cloth.) — The examinations referred to are those 

 of the City and Guilds ne])artment of Technology, and of 

 the Board of Education. Besides general particulars and 

 syllabuses the book contains selected questions from recent 

 examinations, many of which are worked out in detail ; it 

 contains also hints on the preparation for examinations and 

 on the working of examination pajjcrs. \ considerable 

 amount of condensed information is provided. 



Elementary Modern Geometry. H. G. Willis, M..\. Part 

 I (Cl.uindon Press, Oxford, 2s.) — These lessons are, in part, 

 cxpeiimental, in part theoretical. The modern idea is 

 followed according to which it is sought first to familiarize 

 a student experimentally with the more important theorems 

 and problems; he is then in a better position to understand 

 the more strict mathematical logic by which they are later 

 on examined. With this method wc are in thorough agree- 

 imni, though we ?"ecognise that there exist those to whom 

 it will be very repugnant. No attempt has been made to 

 follow Euclid's sequence. 



Examples in Physics. C. E. Jackson, B..^. (Methucn ; 

 price 2s. 6d.) — This book will prove very valuable to 

 the teachers in secondary schools, as it provides a very 

 large number of problems ranging- in diftu-ully from those of 

 very elementary kind to manv of a more advanced kind 



suitable especially to tho.se who are reading for University 

 Scholarships. None of these problems are worked out as 

 illustrations ; hence the book cannot be used alone. Besides 

 several sets of examples arranged according to subject, there 

 is a series of probU'm papers in which mixed examples are 

 given. Answers are provided only to the former. We think 

 that it would be better to provide answers to all. In those 

 cases in which a teacher may wish to set questions for 

 special test purposes it is very ea.sy for him to slightly alter 

 the numerics so as to prevent the student getting a " lead." 

 The presence of answers makes for utility to the private 

 student. 



ZOOLOGY. 



Serials. — \\'e have to acknowledge the receipt of copies of 

 the lirst two numbers (May and June) of a new scientific 

 serial, the (Haslemere) Museum Gazette, whose special pur- 

 pose is to forward the interests of objective education and 

 field study. Many of the articles in the first number are 

 excellent, and, there are some good photographs in both. 

 We fear, however, that the articles on camels and deer 

 and on gnus in the second volume are scarcely calculated 

 to impress naturalists with the value of the new teaching. 

 Wc are told, for instance, in the first of these, that camels 

 and deer form a single family of ruminants, and that adult 

 camels have no upper incisors and pair less of lower ones 

 than giratTes. This blunder is, however, eclipsed bv the 

 following sentence : " .-Ml the gnus are South African and 

 would appear to bear the same relation to the buffaloes of 

 that continent that the North .American bison does to the 

 American buffalo." 



We have also received from the University of California 

 copies of papers on the ostracod crustaceans, of the family 

 Halocypridce, on the shoie-anemone, BunodactU xaiithu- 

 gramma, and on sexual dimorphism in the hj'dioid polyps of 

 the genus Aglaophenia. The dimorphism in the latter 

 group displays itself in the plumules. 



The Menageries of Europe. — Captain Stanley Flower, 

 Director of the Zoological tiardens at Giza, Egypt, has 

 fa\oured us wiih a copy of a report of a mission under- 

 taken by himself last year to visit the chief Zoological 

 (lardens in Europe, in which much interesting information 

 with regard to these establishments and their inhabitants 

 will be found. 



MISCELLANEOUS. 



Thought - Transference, by N. W. Thomas, M.A. (De La 

 More Press; pp. 212 and index, 3s. 6d. net). — This work is 

 a critical and historical review of the evidence for telepathy, 

 and records a number of new experiments carried out in 

 1902 and 1903. It is full of interesting and thoughtful 

 matter on this much-discussed subject, and will alTord much 

 entertainment and food for thought to those who have at- 

 tempted at any time to unravel some of its tangled problems. 



E. A. M. 



Crystal-Gazing, by N. W. Thomas, M.A. (De La Mort 

 Press; pj). 159 and index, 3s. 6d. net). — This work has an 

 introduction by Andrew Lang, and gives a .listory of the 

 practice^ of crystal-gazing. The subject is dealt with from a 

 critical point of view. \ crystal does not seem to be always 

 a necessity, the mental image resulting being capable of 

 production merely through intent gazing into many other 

 more i)rosaic substances. An interesting experience in con- 

 nection with Mr. Balfour and Miss Balfour is related in 

 Mr. Lang's introduction. E. A. M. 



The Unity of Will, by George .Mnslie Hight (London : 

 Ch.-i|)man ;md Hall), 1906; los. 6d. — The author's aim is 

 ambitious, inasmuch as he endeavours to provide us with 

 a new philosophy, a task for which, to our thinking, he is 

 but indilferently qualified. There is a lack of cogency in 

 his arguments, while in many cases he absolutely misin- 

 terprets, .and misrepresents; as for example, when he de- 

 fines .Vgnosticism as " denying and reviling all gods." 

 Mis chapter on the "Sophistries of Science," seems to us 

 crude. Imbued with what he calls " the divine teaching 

 of Plato," an ardent disciple of Schopenhauer, and a 

 " Vedantist," he looks on the world through distorted 

 glasses, and would have us believe that what he sees is true, 

 and only lh.it ! 



