552 



NATURE 



[June 22, 191 1 



added much to its value. ' -e the chapter on 



alloys may be mentioned a.. .. ,...; licularly successful 

 piece of exposition. 



The book reflects as much as ever the spirit of a 

 very true believer in the ionic dissociation hypothesis, 

 and little emphasis is given to the difficulties and 

 objections or to the criticism by which it has been 

 assailed. Although in an elementary work an author 

 can scarcely be expected to go into great detail, it 

 must be remembered that the English student still finds 

 himself in an atmosphere where there is a good deal 

 of objurgation about the ionic theory, and if Prof. 

 Walker had dealt with the difficulties collectively it 

 would probably have been a convenience to students. 



The following points have been noted for remark 

 in the course of reading. On p. 83 the wording may 

 readily give the impression that the vapour rising from 

 a boiling salt solution has a temperature of 100° C, 

 a matter on which there is a widely prevalent mis- 

 conception among students. On p. 227 it would have 

 been well to explain why the Brownian movement is 

 compatible with the conventional assumption that a 

 body suspended in a liquid is subject to equal pressure 

 in every direction. The explanation of " salting out," 

 on p. 347, as a process depending solely on ionic con- 

 centration is scarcely justifiable. Lastly, Prof. Walker 

 has used throughout the book his system of chloridion, 

 sulphation sodion, &c., nomenclature. The present 

 writer took exception privately to this nomenclature 

 when it was first proposed, but was assured that with 

 experience he would learn its value to students. This 

 prediction has not been fulfilled, and whatever philo- 

 sophical defence may be made of the system, he re- 

 mains of the opinion that it is not helpful. A. S. 



BRITAIN'S BIRDS. 

 Britain's Birds and their Nests. Described by A. 

 Landsborough Thomson, with introduction by Prof. 

 J. A. Thomson. 132 drawings in colour by G. 

 Rankin. Pp. xxviii + 340. (London : W. and R. 

 Chambers, Ltd., 1910.) 



ANOTHER gorgeous volume on Britain's birds 

 and their nests ! Truly of the making of books 

 on this subject there seems no end. Happy the pub- 

 lishers, and authors we presume, supported by a public 

 with so insatiable an appetite for British ornithology. 

 We could exhaust the space at our disposal with a 

 mere list of the books and serials on this subject which 

 are issuing or have issued from the press within the 

 past two years and have come under notice in these 

 pages. The name on the title-page of a gifted pro- 

 fessor in a great northern university, as introducer of 

 his son as author has given special zest to the perusal 

 of this particular volume. 



Prof. Arthur Thomson writes an introduction to 

 "Mr. Rankin's beautiful pictures and my son's text." 

 We must, much to our regret, however, confess to 

 considerable disappointment in the volume before us. 

 The text is excellent. Indeed, the various biographies 

 are pleasantly written, and very accurate as a whole, 

 but little really appears to have been left for Mr. 

 Landsborough Thomson to say that has not already 

 been often told. 



NO. 2173, VOL. 86] 



But it is with the plates that fault is chiefly to bi.- 

 found. They are all "very pretty," but we have mor-.- 

 of art than of nature in them. We suspect that the\ 

 are mostly studio pictures rather than out-of-door 

 studies. Without exception the species Mr. Rankin 

 has depicted are the most " proper " series of British 

 birds we have ever made the acquaintance of. They 

 never foul the ground, when 'tis their nature to ; 

 they never disturb a blade of grass or a single pecU 

 of the beautiful flowers that emborder their nests ii; 

 nearly every case. They are indeed the most aesthetii. 

 company we have yet met with, in the choice of nesi- 

 ing sites. 



We miss, too, in many of the plates, the character- 

 istic attitude of the bird represented. There is some- 

 thing lacking in the pose of the herring gull to thos-. 

 familiar with it "in the open." In the thick-knee the 

 beak is too thin and its eye too small; in the corn- 

 crake the true ralline attitude has not been caught. 

 We failed to recognise the nidifugous nestling figured 

 on plate 88, Fig. 3, as a young partridge until wc 

 had consulted the reference. 



As to the eggs figured, it would be quite impossible 

 for even one well acquainted with them in many case^ 

 to determine their parentage from the plates. The;: 

 size — no dimensions being given in the text — is Si\s<. 

 quite undeterminable, and their colour often far froni 

 true to nature. There is no doubt that as regards tini 

 the three-colour process is very often to blame; bu' 

 where it fails some indication should be given in tht- 

 text. 



The author, yet a very young man, shows by this 

 ambitious venture into the world of books that he is 

 possessed of " the passion of the ornithologist," and 

 by it gives promise that we may expect from him an 

 ornithological work "going far beyond the recording 

 of occurrences," to quote his father's words, "and 

 the observations of movements important and indis- 

 pensable as these and similar inquiries are." 



OUR BOOK SHELF. 



An Introduction to Experimental Psychology. By 

 Dr. C. S. Myers. (The Cambridge Manuals of 

 Science and Literature.) Pp. vii+156. (Cam- 

 bridge : University Press, 191 1.) Price is. net. 

 In this little book Dr. Myers gives a very interestin;^ 

 account of modern view's in certain parts of the scien* c 

 of experimental psychology. The topics selected It r 

 discussion, and forming the headlines of succes5i\ 

 chapters, are: — "Touch, Temperature, and Pair 

 "Colour Vision," "The Miiller-Lyer Illusion," " E.v 

 perimental /Esthetics," " Memory," and " Men 

 Tests and their Uses " (two chapters). On each 

 these subjects much important work has been don 

 within quite recent years, and the exceptionally cle; 

 way in which the author sums up the latest results an 

 brings out their theoretical importance will make th 

 book of great value to physicians, educationists, an 

 others who are finding a knowledge of the genen 

 methods and results of the science an indispensa' 

 supplement to their ordinarily-recognised intellect 

 equipment. 



The first chapter contains a full account of the recc 

 researches of Drs. Rivers and Head on human nei 

 division, which have modified so extensively our vie. 

 on tactile sensibility. The chapter on the Miiller 



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