August 4, 1923] 



NA TURE 



161 



Mercury and the moon are concluded to suffer from 

 great extremes of climate, while the high albedo of 

 Venus indicates that much light and heat is reflected 

 without reaching the surface, so that the temperature 

 of the latter may be moderate. A. C. D. C. 



Handbuch der biologischen Arbeitsmethoden. Heraus- 

 gegeben von Prof. Dr. E. Abderhalden. Lieferung 

 94. Abt. IX : Methoden zur Erforschung der 

 Leistung des tierischen Organismus. Teil i, Heft 

 3 : Methoden der zoologischen Forschung. Pp. 439- 

 584. (Berlin und Wien : Urban und Schwarzenberg, 

 1923.) 6.3 Schw. francs. 



The present number of this extensive work is devoted 

 to methods of zoological investigation. The first 

 article, by L. Neumayer, deals with the fixation of 

 tissues for histological purposes, and provides a useful, 

 well-arranged account of the various fixatives, with 

 notes on the different tissues to which they are applic- 

 able. There are also abundant references to the 

 literature of the subject. The second article deals 

 with entomological technique, and is contributed by 

 Albert Koch. In this account are included descrip- 

 tions of all the various entomological methods of 

 collecting and mounting specimens, rearing larvae, and 

 the preparation of material for histological study. 

 The third article, by W. A. Collier, deals with the 

 determination of age in fishes by means of growth 

 phenomena afforded by the otoliths, opercular bones, 

 and scales. 



The last article is by Th. MolHson, and treats of 

 serum diagnosis as a test of affinities as applied 

 to zoology and anthropology. Previous parts of this 

 work have already received notice in our columns, 

 and the present contribution is no exception to the 

 general standard of excellence that characterises this 

 encyclopeedic treatise. 



La Lampe a trots Electrodes. Par Prof. C. Gutton. 

 (Recueil des Conferences-Rapports de Documentation 

 sur la Physique. Vol. 5, i'" Serie, Conferences 11, 

 12, 13. Edite par la Societe Journal de Physique) 

 Pp. 181. (Paris : Les Presses universitaires de 

 France, 1923.) 15 francs. 



Radio engineers will welcome this book by Prof. 

 Gutton. He starts by giving a complete account of the 

 physical phenomena utilised in the three terminal 

 thermionic valve. Full use is made of characteristic 

 curves, and formulae given by Richardson, Langmuir, 

 and Clerk Maxwell are quoted. In the second chapter 

 several good types of apparatus suitable for amplifying 

 are described and approximate formulae are obtained 

 for them. In the next chapter oscillating circuits are 

 given, the theory being well and clearly explained. 

 The theor\' of the methods of using filters to eliminate 

 harmonics is also given. Next comes the theory of 

 detectors and detecting circuits. Finally the arrange- 

 ment to get " negative resistance " is shown and 

 the methods of obtaining high frequency currents by 

 utilising suitable valves are described and their useful 

 applications in making electric measurements are 

 explained. The author defines the resistance of a 

 circuit as " negative " when an infinitesimal reduction 

 of the terminal voltage produces an infinitesimal 

 increase in tlie current. 



NO. 2805, VOL. 1 12] 



Biologie der Tiere Deutschlands. Bearbeitet unter 

 Mitwirkung zahlreicher Fachleute und herausgegeben 

 von Dr. Paul Schulze. Lieferung i. Teil 2 : Spongi- 

 aria. Von P. Schulze. Teil 3 : Cnidaria. Von P. 

 Schulze. (Berlin : Gebriider Borntraeger, 1922.) 



This is the first of a series of booklets giving an account 

 of the general biology, physiology, life history, and 

 ecology of the animals comprising the German fauna. 

 Marine forms are omitted from considerations of space. 

 No systematic treatment is attempted, and only so 

 much of the anatomy, histology, and embryology of the 

 animals is included as is necessary for a proper under- 

 standing of their biology. It is essentially a book of 

 Nature study, wholly excellent in conception, popular 

 in intention and strictly scientific in treatment. It will 

 be issued in a series of pocket volumes, on the lines of 

 Brauer's " Siisswasserfauna," and when completed will 

 form a companion work to Brohmer's " Fauna von 

 Deutschland," in which the systematics of the groups 

 are dealt with. The work is intended for use in the 

 field by students, teachers, and field naturalists generally, 

 and should be of the greatest value in stimulating the 

 study of Nature on a scientific basis. There is room 

 for a similar work on the British land and freshwater 

 fauna ; but until such appears this book will, at any 

 rate partially, fill the need. 



The Common Birds of India. Described by Douglas 

 Dewar and illustrated by G. A. Levett -Yeats. Vol. i . 

 The Sportsman's Birds, Wild Fowl, Game Birds, and 

 Pigeons. Part I. Pp. viii-t-44. (Calcutta and 

 Simla : Thacker, Spink and Co., 1923.) Rs. 2.8. 



Mr. Dewar contemplates a series of volumes (five in all, 

 of about 140 pages each) dealing with the birds of 

 India as a whole and forming a profusely illustrated 

 work of a popular nature designed for the guidance of 

 sportsmen and the non-scientific resident. The first 

 part deals with the ducks, swans, and geese, and 

 though the style is too journalistic, the matter is 

 excellent as a good account of the salient features of 

 these birds and of their general natural history. A list 

 of vernacular names and an easily used key for ready 

 identification are two features of special value which 

 we hope will be continued in later volumes. Mr. 

 Le vett- Yeats 's illustrations add considerably to the 

 usefulness of the work and are worth the expenditure 

 of a little more care in reproduction. There is room 

 for this book, and we hope that Mr. Dewar will receive 

 sufficient support to justify him in carrying the project 

 to completion. 



La Vie des atonies. Par Prof. A. Boutaric. (Biblio- 

 theque de Philosophic scientifique.) Pp. 248 + 4 

 planches. (Paris : E. Flammarion, 1923.) 7.50 

 francs net. 



Prof. Boutaric deals in an interesting way with the 

 recent advances in physics which led to the present 

 view of the structure of the atom. The last part of 

 the subject is treated only very briefly, but the funda- 

 mental experiments are clearly reviewed. The treat- 

 ment is non-mathematical, and the book will be read 

 with interest by those who wish to obtain some con- 

 ception of the radical changes in outlook which have 

 resulted from recent work. There is no index. 



