86o 



NATURE 



[December 15, 1923 



a liorizuntui wind sliould produce ihc 4° turn which 

 Hcrr Lilienthal claims to have measured, but it is a 

 sii^'},'fstion worthy of consideration, and one that may 

 lead to interesting developmrn* S. H. 



Lts Vrincipes de la physiqin. ; .. I'l. Norman R. 

 ( amplK'll. Traduit ct adapts- en Fran^ais par Mme, 

 A. M. I*(:bcllier. (Nouvelle Collection Scientifique.) 

 Pp. xix + 200. (Paris : Y6\\\ Alcan, 1923.) 8 francs. 



A TRANSLATION into French of Dr. N. R. CamplnjU's 

 lx)()k entitled " Phy.sics, The Elements," was suggested 

 to the author by M. £mile Borel, who had been called 

 upon for a notice of the volume in the Rnme philo- 

 sophique. But the length of the original imposed the 

 necessity for considerable abbreviation ; one-third only 

 of this smaller Ixjok is a textual translation, the rest is an 

 abstract, the developments of several pages being some- 

 times reduced to a few lines. Mme. Pcbellier has 

 carried out Iwth the paraphrase and the translation, 

 and her difficult task seems to have been performed 

 most efficiently. The book is rendered more interesting, 

 especially to the English reader, by the preface con- 

 tributed by M. Borel. He eniphasi.ses the great im- 

 portance of the treatise, arising from the fact that the 

 author is an experimental physicist, and moreover an 

 English physicist. Experimental and theoretical work 

 correspond to different forms of activity, and perhaps 

 to different forms of thought. Continental physicists, 

 whether they are French, German, or Italian, are per- 

 haps less purely physicists than the English. It may 

 at least be affirmed that the latter have certain 

 particular qualities, qualities which sometimes shock 

 the savant of the Continent but in practice produce 

 remarkable results. M. Borel proceeds with an in-' 

 tercsting discussion of the language of physics, which 

 he regards as intermediate between the exact language 

 of mathematics and the vaguer language of the vulgar 

 tongue, in which words have only a statistical definition. 

 In its new form Dr. Campbell's work should appeal to 

 a wide circle of readers. 



The Paulsen Arc Generator. By C. F. Elwell. Pp. 192. 

 (London : Ernest Benn, Ltd., 1923.) 185. net. 



As there are more than 20,000 kilowatts of arc 

 transmitters in use to-day, it is highly probable that 

 they will remain in use for many years to come. The 

 British Post Office adopted a 250 kw. Elwell- 

 Poulsen arc generator for the first link of the Imperial 

 Wireless Chain connecting Leafield with Cairo. These 

 two stations are now in operation at two-thirds of the 

 cable rate. The same type of generator is also used 

 at Northolt for communication with the Continent. 

 The Dutch Government is installing a 2400 kw. 

 Poulsen arc, the largest in the world, in Java, to 

 enable it to communicate directly with its colonies. 

 As the author points out, it is the one good system 

 which is not covered by a multitude of patents thought 

 by many to be employed to dictate the terms and 

 conditions under which the other systems may be used. 

 The book begins with a historical introduction, due 

 stress being laid on Duddell's discover}- of the musical 

 arc. The arc generators are then described, and finally 

 clear descriptions are given of the methods and ap- 

 paratus used for signalling and the application of the 

 generator to radio-telephony. 



NO. 2824, VOL. 112] 



Clinical Laboratory Methods. By Prof. R. L. Had- 

 Pp. 204 ♦ > !>lates. (U)nd«>n : H. Kimpton. \i,2 

 lis. net 



The autlior 01 iiiis Iwok has adhered strj( ily n» • 

 object of presenting methotls of carrying out rlini' : 

 laboratory work without in any way di 

 interpretation of the results. The volun!< 

 essentially a manual for the lalwratory worker. Ihc 

 various tests are described briefly, but with attention 

 to every practical detail, and references to original 

 articles are provided with most of the descriptions. 

 The author has limited himself as a rule to one method 

 for each quantitative estimation, apparently with the 

 rather narrow view that one method is suitable in all 

 circumstances. The examination of gastric contents 

 differs considerably from the examination generally 

 carried out in Great Britain, and no cois ' i\ 



given to the fractional test meal. The 

 with the exception of those of blood celL, are ver>- 

 good. Making allowance for slight differences in 

 terminolog)', the clinical pathologist will find in this 

 book a clear description of the laboratory methods in 

 general use. 



Textile Chemistry : an Introduction to the Chemistry of 

 the Cotton Industry. By F. J. Cooper. Pp. ix ' 2^?. 

 (London : Methuen and Co., Ltd., 192 

 net. 

 Mr. Cooper's book covers a good deal of ground in a 

 brief but clear fashion. It reads more like a note-book 

 than a text-book, but is obviously the work of a 

 number of years of teaching, and should be useful to 

 students in technical schools, for whom it is intended. 

 Besides the elementar)- chemistr>^ which serves as an 

 introduction, the author discusses its applications to 

 the textile industry-, and among other things the natural 

 fibres, the chemistn,- of coal, oils, industrial waters, 

 sizes, bleaching, dyeing, and mercerising. Those 

 engaged in teaching the subject will find the book useful 

 and helpful. There are a few minor inaccuracies : a 

 " base " need not contain a metal (p. 66) ; nitric oxide 

 is not absorbed by sulphuric acid (p. 69). The de- 

 scriptions of experiments are not always adequate, and 

 some of them (as that shown in fig. 119) can scarcely 

 have been tried successfully. 



Radio Telegraphy and Telephony. By Vu,,. i.. W . 

 Marchant. Pp. ix+137. (Liverpool: University 

 Press of Liverpool, Ltd. ; London : Ilodder and 

 Stoughton, Ltd., 1923.) ds. net. 

 A VERY large number of books on radio telegraphy 

 and radio telephony have recently been published. 

 Many are of little use to the general scientific reader 

 because they are too elementan.- ; others fail because 

 they are too technical, the authors revelling in technical 

 terms which are in general very vaguely defined. 

 Prof. Marchant seems to have hit on the happy mean 

 in this little volume. The science is accurate, the 

 descriptions are good, and the information is up-to- 

 date. To make assurance doubly sure the author has 

 added a glossary giving good definitions of the technical 

 words used in the text. This book can be recommended 

 to the reader who wants to understand the principles 

 utilised in radio telephony, broadcasting, and directional 

 radio signalling. 



