558 



NA TURE 



[April i i, 1901 



Bi(OH)2N03, separates out. . . . The nitric acid which 

 is hberated passes into solution, so that a portion of 

 the bismuth salt can remain dissolved. There is thus in 

 the solution a chemical equilibrium with respect to the 

 precipitate of basic salt, which is characterised by the 

 concentration of the hydroxyl ion of the water being 

 reduced, by the hydrogen ion of the free acid, to such a 

 value as corresponds with the solubility-product of the 

 basic salt. . . . 



" When sodium thiosulphate is added to bismuth salts, 

 a clear solution is obtained, which slowly decomposes 

 with deposition of bismuth sulphide. The solution 

 probably contains the sodium salt of a complex bismuth- 

 thiosulphuric acid ; for on addition of potassium salts, a 

 very slightly soluble precipitate of K3Bi(S203)3 + H20 

 separates out, which may be looked upon as the potassium 

 salt of this acid. Although it is probable that we are 

 here dealing with a complex bismuth ion, accurate inves- 

 tigations are still wanting. It has been proposed to use 

 the precipitate, which is of a yellow colour, as a means of 

 detecting and precipitating potassium." 



It seems almost a pity that the author, having before 

 him the problem of presenting the material in such a new 

 light, should not have seen fit to depart entirely from the 

 traditional arrangement and set out the whole matter as 

 he himself thought best. Ashe tells us in the preface, 

 his choice was deliberate, and was no doubt well-con- 

 sidered, but the limitation in adhering to the historical 

 treatment makes itself felt here and there throughout the 

 book. It is new wine in old bottles. 



No teacher of chemistry who takes the slightest interest 

 in his profession or in his science can afford to leave 

 this book unread. For the first time he has laid before 

 him a presentation of the facts of elementary chemistry 

 from the standpoint of modern theory, written as only 

 Ostwald could have written it, and compelling attention, 

 whether the reader agrees with the author or not. We 

 understand that an English translation of the work has 

 been undertaken, so that the student also will soon have 

 it at his disposal. J. W. 



AN AMERICAN ZOOLOGICAL TEXT-BOOK. 

 Text-Book of Vertebrate Zoology. By. J. S. Kingsley. 

 Pp. viii -t- 439. Illustrated. (London : George Bell 

 and Sons, 190x3.) Price I2.y. net. 



AMONG the multitude of text-books upon various 

 branches of zoology, or on zoology as a whole, that 

 it has been our fortune to peruse, there are few, if any, of 

 which we can say that they contain so much information 

 in a comparatively small space as is the case with the 

 one before us. Nor is this all ; whereas many works 

 of a kindred nature are written in such an extremely ab- 

 struse style, and are so overloaded with technicalities as 

 to be well nigh unreadable by any but the most thorough- 

 going and uncompromising biological student, the style 

 of the present volume is so easy, and the technical terms 

 are so carefully explained, that a reader with little or no 

 previous knowledge of anatomy or zoology would readily 

 comprehend the nature of the structures described. 



We refer in this connection to structures rather than 

 to animals, because vertebrate morphology, based upon 

 embryology, forms a leading feature of the book, the 

 whole of the first part of which, comprising considerably 

 more than half of the text, is devoted to this section of 

 NO. 1641, VOL. 63] 



the subject. A systematic survey of all the leading- 

 groups of vertebrates constitutes the second moiety. And 

 since there are few works known to us in which these 

 two great divisions of the subject receive such an 

 equal share of attention, on this ground alone Prof. 

 Kingsley's treatise has a decided advantage over many 

 of its fellows. Neither are his descriptions confined to 

 the vertebrates of the present day, their extinct prede- 

 cessors receiving a considerable share of attention. The 

 work is, therefore, thoroughly comprehensive in its scope ; 

 and is, in fact, for the most part exactly what such a 

 treatise should be. .Although it by no means does away 

 with the need for text-books dealing with the palasonto-.' 

 logical aspect of the subject, it serves to indicate that the; 

 day when the zoologist and palccontologist worked on 

 separate lines is gone for ever. ^ 



In a very large number of instances those whose 

 studies are chiefly devoted to the anatomical and 

 embryological side of zoology fail to keep themselves 

 abreast of modern views in regard to systematic classi- 

 fication. But this cannot be laid to the charge of the 

 author of the present volume, who has adopted a 

 thoroughly modern and up-to-date system of classi- 

 fication, as is especially noticeable in his treatment of 

 the fishes and of that group of vertebrates typified by 

 the lampreys and hag-fishes, for which a popular collec- 

 tive title is at present a desideratum. The division of 

 mammals into Prototheria and Eutheria alone is also a 

 feature in accord with modern ideas. 



Indeed, not only is Prof. Kingsley thoroughly up-to- 

 date as regards classification, but in one instance, at 

 least, he is ahead of contemporary opinion. We refer to 

 his treatment of that difficult subject, the classification of 

 birds. In his preface the author states that 



"he has been unable to recognise in the so-called 

 orders of ornithologists groups of birds of more than 

 family rank, while their families are equivalent to genera 

 in the other classes of vertebrates." 



Accordingly, we find the class Aves divided into four 

 ordinal groups only, namely, the (i) Saurura?, as repre- 

 sented by Archasopteryx ; (2) Odontormae, typified by 

 Ichthyornis ; (3) Odontholcae, containing Hesperornis ; 

 and (4) Eurhipiduras, including all living birds. While 

 our sympathies are to a very great extent on the side of 

 the author in this matter, we are by no means prepared 

 to go the whole way with him in this sweeping change, 

 and venture to think that in this, as in most other matters, 

 a via media is to be found. Moreover, we feel sure that 

 if all existing birds are to be included in a single ordinal 

 group, there is not the slightest justification for separating 

 the cretaceous toothed birds (Hesperornis and Ichthy 

 ornis) as separate groups from the mere fact that they 

 retain teeth, and in one instance biconcave vertebrae. 



But all this is, to a great extent, a matter of detail, from 

 which we return to the consideration of the work as 

 whole. 



On one point, and on one point only, we take leave tc 

 consider that the author is unsound, and this is in con 

 nection with nomenclature. As he tells us in his preface 

 he refuses to change well-known generic names on th 

 ground of priority, because " these are the names o 

 morphological literature." If systematic zoologists have 



