ISO SCIENCE PROGRESS 



In the Introduction, perhaps the most valuable part of the book, the 

 method is explained, and great stress is laid on the fundamental differences 

 between students' illustrative examples and research work. The illustrative 

 examples are experiments, often based on historical ones which have helped 

 to establish the laws of chemistry, for the student to perform, modified in 

 such a way as to bring them within the range of his experimental ability and 

 of the apparatus at his disposal in a well-equipped laboratory. The sources 

 of error and tacit assumptions in such experiments are carefully pointed 

 out, the quantitative results obtained by students compared with the standard 

 values, and the students' method contrasted with the research methods by 

 which these standard values were obtained. In this way the author indicates 

 the absurdity of the claim sometimes made, that pupils of school age can 

 discover the composition of water or prove the law of constant proportions. 



The adoption of the term " standard value " instead of the frequent 

 " theoretical value," is an excellent indication of the author's attitude ; 

 quantitative relations in chemistry are experimental results liable to cor- 

 rection, as experimental methods improve, and not theoretical deductions 

 from absolute mathematical laws. 



A valuable section deals with the errors of measurement and their relation 

 to the value of results. The rest of the book is devoted to the development 

 of the fundamental ideas by means of illustrated examples on the nature 

 of chemical change ; compounds and mixtures ; combustion ; the conserva- 

 tion of mass ; the laws of fixed, multiple, and reciprocal ratios ; equivalents ; 

 atomic weights, and the law of combining volumes. In every case the sources 

 of error of the method are emphasised, and the value of the results as evidence 

 carefully considered. 



One can find little fault with the logic of the treatment of the subject, 

 though a few minor errors of fact and expression have escaped the notice 

 of the editors. The peculiar value of the book lies in its insistence on the 

 appreciation of the effect of experimental errors of method on the value and 

 meaning of results, and, while it is unlikely that many teachers will wish to 

 adopt the system suggested in its entirety, it should be read by every teacher 

 and serious student of chemistry. Every page is suggestive, and, if its 

 teaching is taken to heart, students will less frequently assure their mentors 

 that they have found, by volumetric analysis, that a coin contains 92-4846 

 per cent, of silver. 



O. L. B. 



La Chimie et la vie, par Georges Bohn, Directeur de Laboratoire a la Sor- 

 bonne, et Anna Drzewina, Docteur es Science. [Pp. 275.] (Paris : 

 Ernst Flammarion, 1920. Prix 7 Fr. 50.) 



The purpose of this book, which is one of the well-known " Bibliotheque de 

 Philosophic Scientifique," is to show that the study of life and vital processes 

 is, and must be, firmly founded on the science of chemistry. 



Prof. Bohn and Dr. Drzewina are at great pains to interpret all the basic 

 phenomena of life in terms of chemistry, more particularly of physical 

 chemistry, and whilst both chemists and biologists may find in this book 

 much with which to disagree, yet all readers will feel that, substantially, the 

 point of view taken up by the writers is sound. 



Although the original crude idea of vitalism — the so-called " vitalist 

 theory " — was shattered in 1828 by Wohler's synthesis of urea from purely 

 inorganic materials, and has been put even more completely out of court by 

 the rise of synthetic organic chemistry, yet at the present day there are many 

 who wish to argue that the laws governing living matter differ from those 

 which control dead matter. 



The physico-chemical investigations of Arrhenius and others on the rates 



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