NATURE 



.■^2^5 



THURSDAY, NOVEMBER 14, 1907. 



1 .VJETF HAXDBOOK OF INORGANIC 

 CHEMISTRY. 

 Hdiidbiicli der anorganischen Chcmic. Heraus- 



jjeseben von Dr. R. Abcg-g. Band ii., Abt. ii. Pp. 



ix + 700. Price 24 marks. Band iii., Abt. i. Pp. 



x + 466. Price 17 marks. .Abt. iii. Pp. xiv4-876. 



Price 24 marks. (Leipzig : R. Hirzel, 1905-7.) 

 \ H E.ARTY welcome may be extended to this valu- 

 i V able work of reference, which does for inorganic 

 chemistry much more than Beilstein's famous hand- 

 book has done for organic chemistry. It is no mere 

 guide to the recognition and characterisation of 

 the compounds with which it deals. Its aim is 

 beyond this, and its scope is more general. In a 

 u ord, the editor endeavours to make use of the vast 

 accumulation of physico-chemical data of the past 

 twenty vears, and to incorporate them in the descrip- 

 tive portion of the work, exercising a critical selection 

 of the material employed and giving at the same 

 time due consideration to theoretical connections and 

 outstanding problems. The periodic system has been 

 adopted as the basis of classification, and the portions 

 of the work already issued deal with the elements of 

 the second, third, and fifth periodic groups respec- 

 tively. Here it may not be out of place to protest 

 against an aggravating instance of the Teutonic pas- 

 sion for subdivision. The work is to be issued in 

 eight separately paged and indexed volumes, dealing 

 with the eight periodic groups, together with a ninth 

 volume of a general character. One might, there- 

 fore, reasonably expect that the numbers of the volumes 

 would correspond to the group numbers of the elements 

 described. Instead of this, we find the elements of 

 the fifth group described in vol. iii., section iii., those 

 of the fourth group presumably in vol. iii., section ii., 

 and so on. Whether the elements of group 6 will 

 be found in vol. iii., section iv., or in vol. iv., section i., 

 remains for the present a subject of agreeable specu- 

 lation. 



Prof, .\begg, in carrying out his scheme, has secured 

 the collaboration of many eminent workers in the 

 domains of inorganic and physical chemistry. 

 .Amongst those who contribute to the volumes before 

 us we may mention Marckwald (radium), R. J. Meyer 

 (rare earths), Schenck (phosphorus subgroup), 

 Brauner (atomic weights), and Rohland (technological 

 subjects, e.g. mortar, ultramarine). 



The account of the metals of the rare earths and 

 their compounds deserves special mention. The sub- 

 ject is introduced by a general section of nearly fifty 

 pages, in which we are presented with a historical 

 survey, an account of the mode of occurrence and 

 general chemical characteristics of the group, an 

 outline of the methods of extraction and separation of 

 the earths, and a discussion of the valency and atomic 

 weights of the elements. Then follows in detail the 

 subgroup of the cerite earths, with a special account 

 of the separation and purification of lanthanum, pra- 

 NO, 1985, VOL. 77] 



seodymium, neodymium, and samarium. The second 

 subgroup is that of the terbium elements, and the 

 third deals with those of the erbium and yttrium 

 families. 



Another noteworthy feature of the work is the treat- 

 ment of the atomic weights of all the elements by the 

 same hand. Prof. Brauner has accomplished his task 

 admirably. He takes Clarke's " Recalculation of the 

 Atomic Weights" as the source of data up to 1896. 

 and thereafter refers to the original papers, using the 

 reports of the International Commission as a guide. 

 Little is said of the older and less exact determinations, 

 but the more modern work is given in considerable 

 detail, and critically discussed in its relationship, not 

 only to the atomic Weight of the element directly 

 concerned, but to that of other elements which may 

 be involved in the actual experiments. To give an 

 idea of the scale on which Prof. Brauner has written, 

 it may be stated that the. atomic weight of beryllium 

 occupies five and a, half pages, and that of nitrogen 

 no less than thirty-two pages. The author freely 

 criticises the tables of the International Commission 

 in the course of his articles, pointing out, for example, 

 that if N = i4'bi is correct,, which he believes to hv 

 the case, then Ag cannot be io7'93 as given in the 

 international table, but must lie between io7'88 and 

 107.89. 



Prof. -Abegg's " Handbuch " is admirably printed 

 and got up, and must in future form an indispensable 

 item in every properly equipped chemical library. 



ITALIAN BIRDS AND NEOGENESIS. 

 .'Ivifauna Italica. By Enrico Hillyer Giglioli. Secondo 

 resoconto. Pp. xxiv + 784. (Firenze : Coi. Tipi dello 

 Stab: Tipografico s. Giuseppe, 1907.) 



I T.ALLAN ornithologists in particular, and students 

 of palsearctic birds in general, will be grateful to 

 Prof. Giglioli for this revised edition of his most 

 valuable work. Herein he now recognises 496 specie, 

 as entitled to the rank of Italian birds; but this in- 

 cludes species which have only once been obtained 

 within this area, and at least two which man\ 

 ornithologists will refuse to regard as species at 

 all. 



These two exceptions are of more than passing 

 interest, inasmuch as Prof. Giglioli contends that they 

 furnish good examples of " ncogenesis " : of the birth 

 of new species per saltuin. 



The first of these two cases is that of a redstart 

 obtained by Prof. Giglioli from Sardinia. On data 

 which can only be described as unsatisfactory, the 

 author elects to create a new species — Riiticilla nigra— 

 though most of us, on the same evidence, would agree 

 that the- examples on which this new species was 

 based were but melanistic specimens of Ruticilla 

 titys, the common black redstart. This view, he rejects, 

 contending that his own hypothesis is the more reason- 

 able. 



Far more importance is to be attached to the second 

 case, which Prof. Giglioli describes at some length, 

 not only in the pages of this work, but also in the 



C 



