278 Notices respecting New Books. 



On the other hand, industrial chemical processes are highly com- 

 plex, and often extremely subtle ; while their specially kinetic 

 character imposes, as a frequent essential of success, the mainte- 

 nance of a very recondite order of conditions. Upon these condi- 

 tions the theory of chemical structure throws no light. All the 

 great manufactures were founded, have grown, and are still main- 

 tained, in its absence. If structural language and formulae are 

 vised in some of the minor industries, there is no case in which the 

 terminology and symbols might not equally well be made non- 

 structural without detriment to logical reasoning and the power of 

 discovery. Structural formulae, to be legitimate, are nothing but 

 multum in joarvo records of experimental transactions ; but ever 

 since the first of them was written by Higgins, there have been 

 chemists who suppose them to have some extra virtue, to be pic- 

 tures suggesting profounder insight into the constitution of matter. 

 In these metaphysical paths the industrialist may, without blame, 

 decline to wander. Indeed, Dr. Morley himself gives no prac- 

 tical demonstration of the value of chemical structure to manu- 

 facturers ; in particular, under " fermentation," "paraffin," " soap," 

 11 coal-tar," not a hint of help from this source will be found, in 

 fulfilment of the enthusiastic promise of the Preface. Apart alto- 

 gether from the applications of Chemistry, it is notorious that the 

 hypothesis of " structure " fails to explain the numerous instances 

 of isomerism which it dismisses as " physical," — admitted, in fact, 

 on p. 125. Structure suggests nothing as regards colour in the 

 region where it has been most employed, viz. that of the aniline 

 colours themselves ; for the few indications which have been made 

 by Witt cannot be extended to " structures" in general. Structure 

 presupposes all chemical change to be of a mechanical nature ; but 

 there is ample kinetic evidence that it is not. Hence we cannot 

 agree with the author's extremely narrow definition of the object 

 of Chemistry ; which he states (p. 10) " is to study the relations 

 which exist between the properties of bodies and their internal 

 structure, so that we may be able to solve this problem ; given the 

 structure of a chemical compound to deduce all' its properties, 

 whether physical or chemical." 



Among the earlier contents of the work, we may notice a few 

 pages devoted, as is customary, to analysis. These are far too con- 

 densed to be of any real value for teaching purposes, and should 

 be entirely omitted, as having nothing to do with the general scope 

 of the book. Later on (p. 102) there is a discussion of Boiling- 

 points, which would be much more appropriately placed in the 

 terminal chapter on Physical Constants. The discussion itself is, 

 by the way, very ancient history ; Baeyer having shown long since 

 that the properties of homologous series depend upon whether 

 the coefficient of C is even or odd — a conclusion that has received 

 much independent verification, and is, in fact, merely a derived 

 form of the periodic law. This law must always be taken into 

 account in the explanation of the properties of series. " Symmetry " 

 (p. 108 and elsewhere) is a mechanical conception not derivable 

 from a study of chemical reactions, and does not amount to a 

 reason for the production, in any given case, of only a limited num- 

 ber of compounds. Again (p. 468) some decompositions are said to 



