July io, 1913] 



NATURE 



475 



of "Volumetric Gas Analysis," are not exercises 

 in the volumetric as contrasted with the gravi- 

 metric analysis of gases, but have to do with the 

 analysis of solids and liquids by measuring the 

 volumes of gas set free from them. In this 

 section, for instance, are described the methods 

 of estimating nitrates by the Lunge nitrometer 

 and analogous processes. The book is presented 

 in an attractive form, and carries out admirably 

 the purpose of the author and translator to pro- 

 vide an introduction to the larger standard works 

 on gas analysis. 



(4) The German treatise on the theory and prac- 

 tice of the gas industry is a large work of which 

 the present volume constitutes " I. Band, I. 

 Halfte." It. includes the historical development 

 of the principles of mechanics and physics, and 

 the fundamental laws of thermodynamics. The 

 subjects treated include isothermal and adiabatic 

 compression, change of state, evaporation and 

 boiling, viscosity of gases and vapours, specific 

 heats, entropy of water-vapour and vapours used 

 in refrigeration, radiation and conduction, flow 

 of liquids, vapours, and gases. The chemist or 

 engineer who is called upon to handle gases on 

 a large scale will find in this treatise all that 

 he is likely to require in the way of scientific 

 preparation for his work. 



(5) Prof. Sackur's "Text-book of Thermo- 

 chemistry and Thermodynamics " deals with the 

 fundamental laws of heat and of thermodynamics, 

 which are then applied to many of the chief prob- 

 lems of physical chemistry. Thus we find chapters 

 devoted to the theory of solutions, including van't 

 Hoff's equations for osmotic pressure, and to 

 chemical equilibrium based upon the equations of 

 Helmholtz and of van't Hoff, and applied, for 

 instance, to calculate the heat of ionisation from 

 the change of the ionisation-coefficient with tem- 

 perature. There are also chapters on the applica- 

 tions of thermodynamics to electrochemistry, 

 thermoelectricity, and capillarity. The last 

 chapters deal with radiation and with Nernst's 

 "heat-theorem." 



(6) The "Foundation Course in Chemistry" of 

 Messrs. Dodgson and Murray is a well-written 

 book of rather exceptional character. Special 

 attention is paid to topics which have an interest 

 for agricultural students, but this is by no means 

 a drawback from the point of view of the general 

 reader, as it gives an air of reality to the whole 

 treatment of the subject. Structural formulas are 

 freely used for inorganic as well as for organic 

 compounds, and a long chapter is given up to the 

 chemistry of aliphatic compounds under the title 

 "Paraffins and their Derivatives." The chapter 



XO. 228CX. VOL. Q\\ 



on general principles gives a clear exposition of 

 the doctrine of equivalents, but is scarcely an 

 adequate exposition of the atomic theory, as 

 Avogadro's hypothesis, which is the real basis 

 of the modern system of atomic weights, is post- 

 poned to a later chapter, and is there treated only 

 in the most incidental manner. 



(7) The modern system of examinations is 

 responsible for the development of a form of 

 qualitative organic chemistry in which attempts 

 are made to determine the nature of organic com- 

 pounds without carrying out a combustion or 

 quantitative analysis of any sort. This type of 

 organic chemistry is only distantly related to the 

 requirements of scientific or technical research, 

 and has only a very limited range of usefulness. 

 But if the student is aware of the supreme neces- 

 sity of quantitative work there is little harm in 

 allowing him to get some practice in recognising 

 the qualitative properties of the chief radicles. 

 Mr. Shepherd's book gives a scheme whereby the 

 most important groups of organic compounds may 

 be identified by qualitative tests ; the scheme has 

 been in use for some years, and has thus been 

 adequately tested by actual work in the laboratory. 



OUR BOOKSHELF. 

 A Text-book of Experimental Metallurgy and 



Assaying, By A. R. Gower. Pp. xiv+103. 



(London: Chapman and Hall, Ltd., 1913.) 



Price 35. 6d. net. 

 The new edition of this book conforms to the 

 syllabus of the Lower Examination in practical 

 metallurgy of the Board of Education. The first 

 portion of the book consists of a series of experi- 

 ments and explanations to illustrate the reactions 

 occurring in various metallurgical operations, 

 while the second part deals, in quite a satisfactory 

 manner, with elementary assaying. It would have 

 been an advantage if the book gave a little more 

 guidance to the beginner, for very often he does 

 not realise the economic character of metallurgy. 

 For instance, a student sometimes thinks that as 

 sodium carbonate is used in the laboratory as a 

 flux for silica, therefore it would be charged into 

 a blast-furnace smelting copper ores when silica 

 has to be removed. The first chapter of this book 

 may give some students an impression of this 

 kind, for the substances classed as used in metal- 

 lurgical operations are not all commonly so em- 

 ployed, although frequently used in experimental 

 metallurgy and assaying. Then, again, in the 

 chapter "Formation of Alloys," the theoretical 

 quantities of the metals have been given, and no 

 allowance made for loss in the case of volatile 

 metals. 



During the past twenty-five years the book has 

 proved of use, and the present edition should 

 be of assistance to those preparing for the Board 



