NATURE 



THURSDAY, MARCH 9, if 



CHEMICAL PHYSICS. 

 Graham-Otlo's Ausfiihrliches Lehrbuch der Cliemte. 

 Dritte, Ganzlich umgearbeitete Auflage. Erster Band. 

 Uritte Abtheilung. Beziehungen zwischen physika- 

 lischen Eigenschaften und chemischer Zusammenset- 

 zung der Kbrper, herausgegeben von Dr. H. Landolt. 

 Pp. 890 (Braunschweig : ^'ie^veg und Sohn, 1898.) 



THIS work, which has grown out of the comparatively 

 small book on Chemical Physics by Dr. W. A. 

 Miller, first published in 1855, is now complete. Part 

 I., entitled " Physikalische Lehren," was edited by Prof. 

 W'inkelmann, with the concurrence of Prof. Kopp, from 

 the previous edition, and was published in 1S85. Part II., 

 on " Theoretical Chemistr\- and Thermo-chemistr)'," was 

 written by Prof. Horstmann, and was published also in 

 1885. Part III., which is now complete, is divided into 

 nine chapters, of which the first three were published in 

 1893, 2nd are now printed without alteration. 



The editor has secured the assistance of others, 

 eminent in different branches of chemical physics, to 

 write the various sections of the work ; in this way the 

 best information has been obtained, for the subjects are 

 all so rapidly increasing in importance, and so many 

 investigators are engaged on them, that it is practically 

 impossible for one author to produce complete treatises 

 on the several matters with which the book deals. 



The first chapter is on the relation between crystalline 

 form and chemical composition, and consists of 350 

 pages. This commences with an introduction showing 

 the use of crj'stalline forms for distinguishing substances 

 from one another, and the employment of crj'stallisation 

 for the purification of bodies, followed by an account of 

 the geometrical properties of crystals, the forms of which 

 are well described, although the student might have 

 been assisted by some diagrams ; these, however, may 

 be considered unnecessary-, as the crystal forms are fully 

 illustrated in Part I. of this volume. The physical 

 properties of the different systems are given in the form 

 of a table showing the elasticity and cohesion, the 

 optical, thermal, electrical and magnetic behaviour. The 

 first subject dealt with in the chapter is PohTnorphism, 

 twelve pages being devoted to its historj' and discover)- ; 

 then follows a useful table, occupj-ing twenty-three pages, 

 of polymorphous substances, references being given in 

 ever>' case to the original papers from which the inform- 

 ation is obtained : in fact, throughout the book copious 

 references to original papers are given in the form of 

 foot-notes, and in some chapters the year of the public- 

 ation as well as the number of the volume of the 

 periodical is stated ; so that the gradual development of 

 the subjects may be easily traced. It is to be regretted 

 that this is not always done, for the date may be even of 

 more importance than the number of the volume of the 

 journal. The section on Isomorphism, consisting of 141 

 pages, includes an historical sketch of the subject, the 

 employment of isomorphism for the determination of 

 atomic weights, isomorphous series of elements, of 

 which ten groups are given, the molecular volumes of 

 isomorphous bodies and their geometrical and physical 

 NO. 1532, VOL. 59] 



relations and isomorphous mixtures. The third section- 

 is on morphotropy or the change that crystalline forms 

 undergo when certain constituents of compounds are 

 replaced by others : seventy-eight pages are devoted to 

 this subject. This is followed by twenty pages of review 

 and explanations of the whole subject, and by thirty 

 pages of additions. In the preface the editor tells us 

 that this chapter was written by Prof .Arzruni in 1892, 

 and it was published in 1S93. together with the two- 

 following chapters, as before mentioned. 



The second chapter (consisting of 1 1 1 pages , on the 

 relations between the volumes of solid and liquid bodies 

 and their chemical composition, was wTitten by Prof. A. 

 Horstmann about 1S90. The relations of the volumes of 

 gases and of vapours were considered in the second part 

 of this book, so the present chapter deals only with the 

 volume relations of solids and liquids. The atomic 

 volumes of the elements are first considered, and the 

 periodic character of these numbers with increase of 

 atomic weight is pointed out, the molecular volumes or 

 the o.xides are shown to be verj- irregular, although 

 certain resemblances can be traced in oxides of analogous 

 composition, whilst in many isomorphous compounds 

 the molecular volumes are not very different. The 

 molecular volumes of salts containing water of crystal- 

 hsation are discussed, and it is pointed out that all these 

 numbers will be affected by the temperature at which the 

 specific gravities are determined, so that it is not to be 

 expected that a regularity such as obtains in the case of 

 gases will be found. The molecular volumes of isomeric 

 organic liquids are next compared, and there is a table 

 showing the molecular voliunes at 0° and at the boiling 

 points, attention being drawn to the variations under 

 these circumstances. Comparisons are made between 

 the volumes of the halogen substitution compounds of 

 ethane, of isomeric alcohols and ethers and of the 

 isomeric esters of the fatty acids, and lastly the changes 

 of volumes which occur during the formation of com- 

 pounds organic and inorganic. 



The third chapter of thirty-three pages, by Prof. R. 

 Pribram, on the relation between internal friction and 

 the chemical composition of liquid substances, was 

 written in 1892, and was included in the previous 

 publication. .After an historical suney of the methods 

 employed for determining the internal friction or vis- 

 cosity of liquids, it is shown in a table that the viscosity 

 of solutions of salts increases with the basicity of the 

 acid, the acids are compared with the corresponding 

 salts of ammonium, potassium and sodium, and the 

 viscosity of the sodium salts is in all cases the highest. 

 The next comparison is between the viscosity of salt 

 solutions and their electric conductivity ; as a :-ule there 

 is a diminution of conductivity for an increase of vis- 

 cosity ; and a list is given of the viscosities of organic 

 acids and their sodium salts and of solutions of chlorides, 

 sulphates and nitrates of several metals. The chapter 

 concludes with a table showing the viscosity constants 

 of a number of organic liquids, with remarks on the 

 relations existing between them and the composition of 

 the componnds. The work of Thorpe and Rodger is of 

 more recent date than this chapter, but some reference 

 might have been made to it in the reprint. 



The next chapter is by Dr. Willy Marckwald, on the 



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