December 25, 1902] 



NATURE 



171 



OSTWALD'S INORGANIC CHEMISTRY. 



The Principles of Inorganic Chemistry. By Willielm 

 Ostwald. Translated by Alexander Findlay. Pp. 

 xxvii + 785. (London : Macmillan and Co., Ltd.) 

 Price lis. net. 



VIEWS differ regarding the best method of present- 

 ing the facts and theories of chemistry to a 

 beginner. Prof. Ostwald takes the view that " if the 

 present-day chemistry makes greater demands on the 

 power of rational thinking, it also renders the purely 

 memory work of mastering the subject considerably more 

 easy for the student. The growth of the scientific 

 interpretation and elucidation of the separate facts of j 

 chemistry facilitates in the highest degree the impres- 

 sion of them on the mind and their application, and at 

 the same time affords an incomparably greater intellectual 

 enjoyment than the study of the older, essentially de- 

 scriptive, chemistry could offer." Acting on this opinion, 

 Ostwald has introduced physical theories, applicable to 

 chemical facts, "in his stride," as it were. Beginning 

 with some simple metaphysical statements, he develops 

 the fundamental laws of classification and treats of homo- 

 geneous substances, mixtures and solutions ; he next 

 proceeds to consider the law of the conservation of 

 weight and mass, and of work and energy, treating 

 incidentally of the units in which these magnitudes are 

 measured. The next chapter is devoted to " com- 

 bustion," the existence of oxygen and the constancy of 

 proportions ; and the next to a rapid survey of the 

 elements and their properties. The subsequent treat- 

 ment is, in a restricted sense, systematic ; the remaining 

 chapters treat of oxygen, ozone, hydrogen, water, 

 hydrogen peroxide, chlorine and hydrochloric acid, 

 oxides of chlorine ; bromine, iodine and fluorine, 

 sulphur and its compounds, and, in short, the elements 

 generally termed non-metals and their compounds ; the 

 metals and their salts complete the list. 



But the discursive nature of treating the subject may 

 be gauged by the amount of space — 92 pages — devoted 

 to the consideration of oxygen, hydrogen and water. 

 Under the heading "Oxygen," not merely are the pre- 

 paration and properties of the element considered, but 

 also velocity of combustion, the influence of temperature 

 on that rate, Boyle's and Gay-Lussac's laws, the temper- 

 ature scales, degrees of freedom of a gas, the construc- 

 tion of curves, the liquefaction of gases, the solubility of 

 gases, and ozone ; the condition of allotropy is also shortly 

 discussed. Under " Hydrogen "come methods of drying 

 gases, molecular weights (here termed "molar" weights), 

 the compressibility of gases at high pressures, diffusion, 

 the law of partial pressures, the law of effusion of gases 

 and spectrum analysis ; also, a propos of the combustion 

 of hydrogen, the law of mass action, chemical equilibrium 

 and the influence of solid substances thereon ; and 

 lastly, catalysis, introduced by the catalytic action of 

 platinum in causing combination between oxygen and 

 hydrogen. Under the heading " Water," we find the 

 law of continuity, graphic interpolation, coefficient of ex- 

 pansion, degrees of freedom of liquids, supercooling, 

 heats of fusion, heat-units, vapour-pressures, heats of 

 vaporisation, supercooled vapours, phases of water, ice 

 and steam, and the triple point ; next water as a solvent, 

 NO. 1730, VOL. 67] 



and the relations between lowering of freezing point and 

 depression of vapour pressure caused by salts ; volume 

 relation of gases, '"combining" weights, symbols and 

 formula;, equations, and the atomic and molecular 

 hypotheses. 



Now Prof. Ostwald's style is excellent, and full 

 justice is done to it by Dr. Findlay's translation ; hence 

 the book is most readable and interesting ; the theoretical 

 disquisitions are most clearly stated and arranged in an 

 orderly manner, each point being taken up when its 

 turn has come, but the reviewer doubts whether a 

 beginner would gain much from a perusal of the book. 

 For a teacher who is already familiar with the facts of 

 chemistry, innumerable hints are to be found, almost on 

 every page. But after all, the young chemical student 

 has to familiarise himself with the facts of chemistry, and 

 gilding the pill, even with fine gold, is apt to interfere 

 with its assimilation. For a man of advanced years, 

 even though he be no chemist, who can appreciate the 

 logical arrangement of the book, much enjoyment may 

 be obtained from it ; but from long experience of the 

 powers of mind of junior students, the reviewer doubts 

 whether more than two or three specially gifted individuals 

 out of a large class would retain much in their 

 memories. 



Just as in learning a language it is absolutely necessary 

 to acquire the common verbs, prepositions and adverbs 

 by heart, and to have at least some idea of the syntax 

 before analytically parsing the sentences, attending 

 to every subtlety, so with chemistry. A large number of 

 facts and their experimental demonstration must become 

 familiar, and it is then time to build up laws on these 

 facts. 



However, as stated at the outset, theie are many 

 methods of presenting such facts ; and if the young 

 student has energy to follow two or three methods of 

 presentment, he will be a gainer. It appears to the 

 reviewer that it would be better to reserve this method 

 of considering the subject until a year, or perhaps more, 

 has been spent in the more usual course of study. The 

 effect of reading such a book at that stage is sure to be 

 most stimulating, and will enable the reader, not only to 

 revise his knowledge, but to enrich it by many necessary 

 additions. 



It is unnecessary to mention that the work is entirely 

 up to date, and that the translator, as an old pupil and 

 friend of the author, has completely entered into the 

 spirit of the matter ; he has left no trace of its German 

 origin in the excellent English of which he is a master. 



W. R. 



A NEW THEORY OF THE UNIVERSE. 

 On an Inversion of Ideas as to the Structure of the 

 Universe. By Prof. Osborne Reynolds, F.R.S. Pp. 

 44. (Cambridge : University Press, 1902.) Price 

 is. 6tf. net. 



THIS is a short description of a new theory of the 

 universe which formed the subject of the Rede 

 lecture last June. All such theories must satisfy two 

 conditions. The structure must be dynamically possible, 

 and the results deduced by dynamical reasoning from the 



