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XXIII. Notices respecting New Books. 



The Study of Chemical Composition. An Account of its Method and 

 Historical Development. By Ida Pketjnd, Staff Lecturer and 

 Associate of Newnham College, Cambridge. Cambridge : At the 

 University Press. 1904. Pp. xvi + 650. 



T\7E can heartily commend this book, not only to students of 

 Y * chemistry and physics, but to all who take an interest in the 

 development of that method of study to which the stately edifice 

 of modern science owes its existence. In an elementary course of 

 chemistry, there is but little time or opportunity to refer to the 

 historical development of the subject ; and even many advanced 

 students have but a very imperfect notion of the struggles by which 

 our present spoils of knowledge have been won. The book before 

 us should do much to remedy this defect, and to supply that con- 

 necting link with the past without which a correct sense of historical 

 perspective is impossible. 



After a clearly-written introduction in which the author deals 

 with the method of the inductive sciences, observation, gene- 

 ralization and law, hypothesis and theory, we are introduced in 

 Chapter I. to the phlogistic theory, whose rise and decay are traced 

 in detail. Lavoisier's important investigations in connexion with 

 the law of the conservation of mass are next dealt with in Chapter 

 II., and this is followed by a discussion of exact and approximate 

 laws in Chapter III. The next few chapters deal with Berthollet 

 and the law of mass action, Proust and the law of fixed ratios, 

 Dalton and the law of multiple ratios, Eichter and the law of 

 equivalent ratios, combining or equivalent weights, hypotheses 

 prior to 1800 regarding the ultimate constitution of matter, Dalton 

 and the atomic hypothesis, GJ-ay-Lussac and the law of the combining 

 volumes of gases, Avogadro and the molecular hypothesis, Can- 

 nizzaro and the application of Avogadro's hypothesis to the 

 determination of molecular and atomic weights, and Petit and 

 Dulong and the law of atomic heat. Chapter XV., " Mitscherlich 

 and the Connection between Crystalline Porm and Chemical 

 Composition," is deserving of special notice as furnishing a most 

 excellent introduction to crystallography — a much neglected subject. 

 Chapter XVI. deals with Mendeleef and the Periodic Law, Chapter 



XVII. with Kekule and the doctrine of valency, and Chapter 



XVIII. with Berzelius and isomerism. Lastly, the important 

 speculations regarding the probable structure of the atom which 

 are the outcome of recent researches on the discharge of electricity 

 through gases and on the nature and properties of radio-active 

 bodies, form the subject-matter of the concluding chapter. 



A copious index is provided, and — like all volumes forming 

 the Cambridge Physical Series, to which it is the latest addition — 

 the book is beautifully printed. 



