646 Notices respecting New Books, 



creative life of the almost inspired thinker. Both are well treated : 

 the first with sympathy, and the last with real scientific insight. 



The portraits are a most interesting feature, and are from the 

 German edition. Every thing about the work is attractive, and 

 few English scientific men will care to be without this memorial 

 of one of the greatest discoverers of the generation which is 

 passing away. 



A History of Chemical Theories and Laws. By M. M. Pattison" 

 Muir, M.A. New York : John Wiley & Sons. London : 

 Chapman & Hall, Ltd. 1907. Pp. xx + o55. 

 However convenient and, in some cases, necessary it may be, for 

 purposes of elementary teaching, to neglect the past history of a 

 science, and to group the results achieved by it in a manner calcu- 

 lated to smooth the path of the beginner and to present the 

 various aspects of the subject to him in the most natural order of 

 logical sequence, there can be no doubt that no serious student 

 can properly estimate the relative importance of the various units 

 which go to make up a harmonious scientific theory without some 

 study of the frequently slow and painful steps by which our 

 present store of knowledge has been acquired. In chemistry — 

 more, perhaps, than in any other science — the progress of truth 

 has frequently been interfered with by more or less blind gropiugs 

 in the dark, by fanciful and utterly unjustifiable interpretations of 

 results, and by dogmatic insistence on errors which had become 

 traditional and difficult of uprooting. All advanced students of 

 chemistry will feel deeply grateful to Mr. Pattison Muir for the 

 extremely interesting sketch of the evolution of chemical theory 

 contained in the book under review. It is not a history of 

 chemistry, nor did the author ever intend it to be such ; it is an 

 attempt " to set forth . . . the main lines along which the science 

 of chemistry has advanced to its present position." It is thus a 

 history of ideas and theories, rather than of chemical facts and 

 their discoverers— a history of the attempts to furnish answers to 

 the two fundamental questions with which chemistry has to deal, 

 viz., " what is a chemically homogeneous substance ? " and " what 

 happens when chemically homogeneous substances interact ? " In 

 accordance with this plan the book is divided into two parts, 

 dealing respectively with the attempts made to answer the above 

 questions. Owing to the restrictions which the author has volun- 

 tarily imposed on himself, he is able to deal with some aspects of 

 the subject much more fully than would otherwise have been 

 possible, and as a result the treatment has gained in richness and 

 relief. In connexion with the earlier history of chemical theories, 

 we may perhaps suggest that, for the sake of those readers who 

 have not previously studied the history of chemistry, it would be 

 advisable to indicate more clearly the modern meanings or equiva- 

 lents of the terms used by the early writers, as this would somewhat 

 facilitate the reading of certain chapters of the book. This has, 

 to a certain extent, been done by the author, but not quite so f iilty 

 as would appear to be desirable. 



