620 



NA TURE 



[Oct(M!1:;r 29, 1896 



advantage, especially those dealing with the estimation 

 of halogen and of sulphur, but merely in order that space 

 might be found for a description of the analysis of 

 organic salts, X:c., and of the methods used in the 

 determination of vapour density and molecular weight ; 

 such an alteration would make this general part even 

 more useful as an introduction to research-work. 



In Part ii. the author gives instructions for the 

 preparation of a large number of compounds, the 

 examples being carefully chosen in order to illustrate 

 practically all the more important reactions, including 

 those only recently discovered. After each prepara- 

 tion there follows a brief account of the theory of 

 the reaction which has been studied, other practical 

 methods by which similar results may be attained are 

 pointed out, and, with the aid of numerous examples, the 

 general application of the reaction is considered ; the 

 properties of the preparation, and of the class of substances 

 to which it belongs, are also described, the more im- 

 portant reactions being illustrated by test-tube experi- 

 ments which the student is directed to perform. The 

 classification of the preparations into " alipathic " and 

 "aromatic," which is here adopted, and the treatment of 

 the former before the latter, are no doubt necessary from 

 an author's point of view ; but if this course is strictly 

 adhered to in practice, it has the disadvantage that the 

 student undertakes some of the more difficult prepara- 

 tions before he has had any experience. Prof Gattermann 

 does not indicate whether the preparations are intended 

 to be carried out in the given order ; but as each is 

 practically complete in itself, there is no reason why a 

 little discretion should not be exercised, the easier ones 

 being taken first. 



This part of the book is an elegant combination of 

 practice and theory, and cannot fail to arouse and 

 maintain interest in both ; it will doubtless have the re- 

 sult which the author desires, namely, "that the student 

 already, during the period given to aboratory work, 

 becomes familiar with the most varied theoretical know- 

 ledge possible, which, accjuired under these conditions, 

 adheres more firmly, as is well known, than if that 

 knowledge were obtained exclusively from a purely 

 theoretical book." ^ 



In Part iii., which consists of a few pages only, the 

 author gives details of the preparation of some in- 

 organic compounds (the halogen acids, phosphorus chlor- 

 ides, &c.) W'hich are very frequently used in organic work. 



It would be hard, indeed, to express anything but a very 

 favourable opinion of Prof Gattermann's excellent book 

 as an introduction to practical organic chemistry ; a 

 student who reads it carefully will save himself labour, 

 time, and material, and will avoid many of the usual 

 mistakes and accidents ; at the same time, he will gain a 

 sound practical knowledge which will help him to 

 commence research with a good prospect of success. 



Dr. Shober's translation is very readable, although it 

 bears traces of the impress " Made in Germany " : the 

 nomenclature might, perhaps, have been brought more in 

 accordance with that adopted by the Chemical Society, 

 but inasmuch as almost every chemist has his own system, 

 it is impossible to please all. 



Since the advance of organic chemistry in this country 



1 Ajithor's preface. 



NO. 1409. VOL. 54] 



must, in some measure, depend on the nature of the 

 available text-books, both the author and translator 

 deserve our thanks for providing us with a work such as 

 the present one. F. S. K. 



OUR BOOK SHELF. 



The Dcti'ction ami Measurement of Inflammable Gas 

 and I'apoiir in the Air. By F. Clowes, l)..Sc., and 

 Hoverton Redwood, F.R.S.E. Pp. xii -I- 206. London : 

 Crosby Lockwood and Son, 1896.) 

 This book describes the evolution of the '" hydrogen- 

 lamp " for the detection and estimation of fire-damp in 

 coal-mines, as well as for the detection of other gases 

 and vapours which may fornj explosive mixtures with 

 air. In an historical introduction, andin various appen- 

 dices. Prof Clowes gives an account of the \arious 

 appliances which have been brought forward for the 

 detection of small quantities of fire-damp, and each 

 method in turn is criticised and condemned in view of 

 the " superior advantages " of the hydrogen-lamp. How 

 far it is desirable for the inventor of a particular process 

 to write a book on the general subject of gas-testing, and 

 to criticise rival inventions in it, need not be discussed ; 

 the literary character of the book certainly sutfers, as 

 witness the following : — "The advantages of the hydrogen- 

 flame render it so distinctly superior to every other 

 testing-flame, that those who have once become familiar 

 with its use prefer it to all other flames in delicate and 

 accurate testing.'' This is not taken from a page of ad- 

 vertisements, but is the last paragraph of the "historical 

 summary." 



Apart from this one fault we have no criticism to make. 

 Prof. Clowes has put together in a convenient form a 

 number of bits of information useful to mining engineers, 

 and has given full details of his own experiments on a 

 difficult and important subject. The success of the 

 hydrogen-lamp has passed beyond the experimental 

 stage. It is a practical instrument, which we feel con- 

 fident will lead to increased safety in mining industry. 

 Prof Clowes shows how the lamp can be used for detect- 

 ing other inflammable gases, as well as for showing the 

 presence of carbonic acid in the air ; and Mr. Hoverton 

 Redwood contributes a chapter on its use in detecting 

 inflammable vapour from petroleum. The construction 

 of petroleum-tank steamships has made an accurate test 

 for petroleum vapour necessary, and the hydrogen-lamp 

 of Prof Clowes has been successfully adapted for this 

 purpose. The book is capitally illustrated. 



Mensuration. By Alfred Lodge, M..-\. Pp.274. 'London: 



Longmans, Green, and Co., 1895.) 

 In this book the student is assumed to have an elemen- 

 tary knowledge of mensuration, and to know, also, some- 

 thing of elementary trigonometry as far as the solution of 

 triangles ; in fact, it is intended chiefly for senior students. 

 In its arrangement, volumes, surfaces, and solids are first 

 dealt with ; then follow chapters on spherical lunes. 

 triangles, polygons, regular polyhedra, and plane figures. 

 An interesting chapter is given on the mensuration of such 

 earthworks as would be required in excavating cuttings 

 for roads or railways, and in the construction of em- 

 bankments. Chapter viii. is confined chiefly to the 

 use of logarithms in solving triangles, while the following 

 one is devoted to the relationship between British and 

 metric measures. .-\ short survey shows that the book 

 should prove serviceable to those readers who wish to 

 acquire a sound knowledge of the theoretical side of 

 this subject. It may be mentioned that in the deter- 

 mination of volumes of solids the formuke are, for the 

 most part, all based on Simpson's rule. .'\ great number 

 of both numerical and algebraical examples are scattered 

 throughout, and very neat and instructive figures are 

 inserted in the te.xt. 



