522 



NATURE 



[September 27, 1900 



is the African elephant, which Fred. Cuvier, in 1835, 

 proposed to erect into a distinct genus under the name 

 of Loxodonta." A more unfortunate error, complicated 

 by a more unfortunate slip, could scarcely be conceived. 



In one other passage where the author ventures into 

 the domain of palaeontology he has scarcely been more 

 successful, since (p. 308) he unhesitatingly accepts the 

 alleged Cretaceous age of presumed Hyracoid remains 

 discovered in the Argentine. Possibly, however, his 

 omission to mention that fossil " dassies " occur in the 

 European Pliocene may be due to the time that the 

 volume has taken in passing through the press, although 

 the fact was announced at the Zoological Congress held 

 at Cambridge in 1898. 



Much general interest will attach to Mr. Sclater's 

 account of the two large mammals which have un- 

 doubtedly become extinct in South Africa in modern 

 times. With regard to the first of these, the author 

 remarks that the last blaauw-bok {Hippotragus leuco- 

 phoeus) was probably killed in 1799 ; and that, in addition 

 to several pairs of horns, five complete mounted speci- 

 mens are known to be preserved. The quagga {Eqttus 

 quagga) he believes to have survived in the Orange 

 Colony till at least 1878, although it is difficult to obtain 

 exact information owing to the Boers confounding this 

 species with Burchell's zebra. Of the white rhinoceros 

 it is considered not improbable that a few may still 

 survive in Zululand, although it is sad to learn that no 

 less than six are reported to have been killed so lately as 

 1894, one of these being exhibited in the museum at 

 Pretoria. The latest information with regard to the 

 white-tailed gnu is that a few herds were, till recently, 

 preserved on some farms in the Orange Colony and the 

 Transvaal ; while it is suggested that a few stragglers 

 may survive in the Kalahari, Gordonia and German 

 South-west Africa. Much anxiety will now be felt by 

 naturalists as to what has happened to the gnus, and also 

 to the blesboks, till lately preserved in the Boer 

 Republics ; and it is to be hoped that those responsible 

 for the settlement of these districts will do all in their 

 power to protect such remnants as the war may have 

 left. 



We hope ere long to have the pleasure of congratulating 

 Mr. Sclater on the completion of his task. R. L. 



OUR BOOK SHELF. 



Acetyl eney a Handbook for the Student and Manufacturer. 

 By Vivian B. Lewes, F.I.C., &c. Pp. xxvi -I- 978. 

 (Westminster : Archibald Constable and Co., Ltd., 

 1900.) 



In this handsome volume of nearly 1000 pages. Prof. 

 Lewes has presented the English reader with a hand- 

 book on the manufacture and use of acetylene which in 

 completeness of scope and wealth of illustration will 

 compare with its French and German rivals. 



In the first part (consisting of four chapters) the 

 scientific history of acetylene and its properties is set 

 forth with considerable detail ; useful summaries of many 

 researches are given, and references to the original 

 memoirs are added. The question of the discovery of 

 " commercial calcium carbide " is discussed with dis- 

 crimination, the chief credit being assigned to the 

 Canadian engineer, Mr. T. L. Willson. The reactions of 

 NO. 161 3, VOL. 62] 



acetylene, especially with metallic salts, are fully 

 considered. 



Part ii., the most important in the book, describes the 

 development of the electric furnace, and its special 

 adaptation to the manufacture of calcium carbide. The 

 generation of acetylene by the action of water on the 

 carbide is next considered, and then the question of 

 impurities and their removal is discussed. Most of the 

 figures illustrating this portion of the book are clear and 

 satisfactory, but a few are indistinct and on too small a 

 scale. The chapter on the combustion of acetylene is 

 illustrated by a number of useful drawings of burners 

 and flames, and -full data are given for a comparison 

 between acetylene and other methods of illumination, 

 both as regards prime cost and working expenses. We 

 think Prof. Lewes has shown himself eminently fair in 

 the discussion of this subject. 



The method of treatment adopted by the author 

 naturally leads to some repetition, but in a book of 

 reference this will not be felt an inconvenience. It was 

 perhaps hardly necessary to give the author's " acetylene 

 theory of luminosity" twice over. In a new edition we 

 hope that the number of small inaccuracies will be re- 

 duced. We did not expect to find a chief gas-examiner 

 saying that " sulphur dioxide, in ill ventilated apart- 

 ments, will absorb oxygen and moisture from the air, and 

 will in this way become converted into minute traces of 

 sulphuric acid, which, concentrating themselves upon 

 any cold surface in the room, give rise to corrosion," &c. 

 The Harcourt pentane standard is not approved of, 

 apparently, by Prof. Lewes, who states that it was first 

 described in 1887. It was described ten years earlier. 

 The specific heats of gases given on page 609 are in- 

 correct, and several names are wrongly spelled, e.^. Vielle 

 should be Vieille (p. 68), Smithell should be Smithells 

 (563). In spite of small errors, the book is a mine of 

 information, and will be useful, both to chemical students 

 and to others interested in the making and use of 

 acetylene. 



Wireless Telegraphy and Hertzian Waves. By S. R- 



Bottone. Pp. 113. (London: Whittaker and Co.> 



1900.) 

 There are many whose interest in wireless telegraphy 

 will take the form of a desire to experiment for them- 

 selves, and who, whether from inclination or necessity, 

 will prefer to do so with home-made apparatus. To these 

 the little book before us will especially commend itself. 



The first half of Mr. Bottone's work is devoted to 

 "preliminary notions," "historical considerations," and to 

 a chapter on electric waves. This earlier half seems to us 

 to leave much to be desired. Thus a clear elementary 

 description of the fundamental experiments of electrical 

 science is followed (p. 12) by a very obscure summary of 

 the properties of electric charges and currents. Again, 

 the confusing of the words " stress '' and " strain " will not 

 please the reader accustomed to the modern strict usage 

 of these terms. 



The description of apparatus in these earlier chapters 

 is often involved, and many sentences will be found 

 which through faulty punctuation or other small errors 

 are not at once intelligible. A considerable amount of 

 repetition also seems to occur, apart from deliberate 

 recapitulation. 



The later part of the book includes a number of 

 really good descriptions in detail of how to make such 

 apparatus as a small induction coil, a Wimshurst 

 machine, a relay, or a coherer ; and the author is evidently 

 familiar with the little practical difficulties which arise. 

 Possibly the importance of making a dimensioned draw- 

 ing before starting work might have been emphasised ; 

 but in all other respects these "workshop recipes" seera 

 very complete and well suited to the wants of those about 

 to make such apparatus. D. K. M. 



