434 



NA TURE 



[Septembi 



923 



the colour blind are described. In this chapter, as in 

 others, the author shows his appreciation of the physio- 

 lofiical aspects of the subject. The section on photo- 

 chemistry deals with the i)hotographic process, the 

 bleaching of the vi.sual puq)le, the spectral sensibility 

 curve of Volvox globator, and the photo-sensory pro- 

 cess of the clam, Mya Arenaria. The two concluding 

 chapters deal with phototherapy and dangerous light 

 sources, such as the quartz mercur>' arc, iron and 

 tungsten arcs, which emit ultra-violet radiations of 

 wave-lengths shorter than 2930 A.U., and cause a pain- 

 ful inflammation oi the eyes and skin. The last chapter 

 deals with the psychology of colour. The book is 

 very well illustrated. F. W. Edridge-Green. 



Die Fernrohre und Etitfermmgsmesser. Von Dr. A. 

 Konig (Naturwissenschaftliche Monographien und 

 Lehrbucher, Band 5). Pp. vii-H207. (Berhn : 

 J. Springer, 1923.) 7^. 6i. 



This book expresses the views of one whose academic 

 knowledge is supplemented by considerable practical 

 experience ; it contains, therefore, much information 

 that a designer of optical instruments will appreciate. 

 There are three sections dealing comprehensively with 

 the various types and details of telescopes, micro- 

 meters, and rangefinders. 



The author has unconsciously rather impaired the 

 agreeable impression of impartiality created by the 

 text through the association of the name of his firm 

 with so many of the instruments illustrated. For 

 example, it might be concluded that the well-known 

 design of dial sight which reflects so much credit upon 

 another German firm was attributable to Messrs. 

 Carl Zeiss. 



Many of the illustrations have been reproduced 

 from other works and are already well known, and the 

 author has not completely solved the very difficult 

 problem of representing without confusion the paths 

 of rays through prisms of complex form. He describes 

 the theoretical Ramsden eyepiece which has the field 

 lens in the focal plane, but illustrates the practical 

 Ramsden having the field lens f/4 beyond the focus. 

 Too favourable an impression of the practical clearness 

 of optical glass is created by indicating the absorption 

 for A = 0-48 /x. The date and place of Kepler's death 

 as given do not agree with those inscribed upon his 

 tomb, and stereoscopic rangefinders are advocated for 

 reasons that are no longer accepted by responsible 

 German naval officers. 



Notwithstanding these and other minor criticisms 

 that might be expressed. Dr. Konig's book is an 

 excellent one that should prove most useful to all 

 directly or indirectly interested in the science of optical 

 instruments. James Weir French. 



Die europdischen Bienen (Apidce). Bearbeitet von 

 Prof. Dr. H. Friese. Lieferung 2. Pp. 1 13-208 -1- 

 Tafeln8-i3. lo^- Lieferung 3. Pp. 209-304 -f- Tafeln 

 14-19. ss. Lieferung 4. Pp. 305-400 + Tafeln 20- 

 25. 55^. (Berlin und Leipzig : W. de Gruyter und 

 Co., 1922-1923.) 



The first part of this work has already been noticed in 

 our columns. Parts IL to IV., which have recently 

 come to hand, are devoted to an account of the be- 

 ha\nour, nesting habits, distribution, parasites, etc., of 



NO. 2812, VOL. 112] 



typical members of the various genera of Eurfjpean 

 bees. The classification adopted is essentially bio- 

 logical, bees being treated as solitary, social, and 

 parasitic as the case may be. Perhaps the best feature 

 in the book is the descriptions of the nesting habits, 

 which are accompanied by numerous figures, and 

 practically all the plates are devoted to various phas«( 

 of this subject. The majority of the illustrations are 

 original and of a high standard of excellence, and many 

 of the plates are exceedingly attractive. The value of 

 others is somewhat marred by the addition of too much 

 extraneous scenery in the shape of hilk, roads, etc., as 

 well as buildings. The author's object no douin is to 

 portray the surroundings in which the species live. 

 The genera Osmia, Halictus, and Chalcidoma are 

 particularly well treated. Chalcidoma occupies no less 

 than six of the plates, but the great genus Andrena 

 scarcely seems to come in for its adequate share of 

 illustration. We look forward to the appearance of the 

 final instalment of the work, and can cordially recom- 

 mend the parts already issued as a trustworthy and 

 very readable presentation of the hal)its nnd trnnoniv 

 of the insects of which it treats. 



Elements of Natural Science. By W. Bernard Smith. 

 Part 2. Pp. viii-(-268. (London: E. Arnold and 

 Co., 1923.) 55. 6d. 



Public School science masters ha\e not yet arrived at 

 complete agreement as to how and what science should 

 be taught in general education. The majority of their 

 pupils are not destined for careers and professions in 

 which a definite training in any one branch of science 

 is essential ; yet all, in this age which has reahsed that 

 science is power, should be taught something of the 

 scientific method, and should gain at least an introduc- 

 tion to each of the subjects on which personal and 

 national welfare depend. Mr. Bernard Smith has here 

 made an interesting attempt to steer a safe course 

 between the Scylla of specialist teaching and the 

 Charybdis of smattering, but in places sails perilously 

 near the whirlpool. This Part IL is concerned with 

 electricity and magnetism, astronomy, geology*, biology, 

 physiology, and hygiene, and the principles of agri- 

 culture. Of these the first three are handled rather 

 more successfully than the others ; but throughout 

 the needs of an ordinarily intelligent and well-educated 

 " man in the street " have been kept in mind. 



Chemistry, Inorganic and Organic: With Experiments. 

 By C. L. Bloxam. Eleventh edition, revised by 

 A. G. Bloxam and Dr. S. Judd Lewis. Pp. x-^832. 

 (London : J. and A. Churchill, 1923.) 365. net. 



The first edition of Bloxam's textbook was published 

 in 1867. It must evidently have undergone very ex- 

 tensive revision. There can be scarcely a page of 

 the original book left. The revision in the present 

 edition has been wisely and thoroughly done, and the 

 book is one which will be found most useful for reference 

 purposes in schools or institutions where large treatises 

 are not available. It covers the whole of chemistr}' in 

 an interesting manner, and the descriptions of experi- 

 ments are especially noteworthy. Many of these were 

 new to the reviewer. The book will probably be found 

 most useful to medical and pharmaceutical students for 

 reference purposes, although it has a wider appeal. 



