February 21, 1908] 



SCIENCE 



305 



their constitution as either elementary or com- 

 pound, the work of Dalton, and the differentia- 

 tion of atom and molecule, with all the history 

 which is implied by these phrases, occupy three 

 long chapters. Three briefer chapters dealing 

 with the extension of Avogadro's hypothesis to 

 dilute solutions, allotropy and the inert ele- 

 ments, together with an appendix on nomen- 

 clature, complete the first part of the book. 

 This part (200 pages) deals, therefore, with 

 the evolution of the conception of the sub- 

 stance and of all that is connoted by the terms 

 atom and molecule. 



The second and longer part deals with 

 chemical interaction in the broadest sense of 

 the term. The first section of this part treats, 

 in six chapters, of the classification of sub- 

 stances by their chemical properties, molecular 

 structure as an expression of chemical be- 

 havior, and the periodic system as the basis 

 of a formulation of both physical and chemical 

 behavior. It includes also a chapter on ioniza- 

 tion in solution and electronic ionization, 

 with a full account of J. J. Thomson's 

 coi-puscular hypothesis of the constitution and 

 behavior of atoms. The second section of this 

 part deals with the conditions and laws of 

 chemical change. In one chapter chemical 

 affinity from Newton to Van't Hoff is re- 

 viewed. In another, chemical equilibrium is 

 brought down to Ostwald's Faraday Lecture. 

 In the last chapter the relation between 

 chemical and optical properties, from Biot to 

 Perkin, and thermochemistry from Lavoisier 

 to Clarke, are treated with considerable full- 

 ness. 



As the author says, othere might have 

 made a different selection of material — one 

 misses, for example, the work of Werner when 

 valence is discussed — but the selection is on 

 the whole excellent. The feeling of growth 

 and organic inter-relation is kept admirably 

 before the reader. The style is attractive and 

 the mode of presentation lucid and interest- 

 ing. The book is not only suggestive, but 

 highly readable — there is not a dry page in it. 

 It is not mere book-making, either. Every 

 statement is based upon a careful study of 

 the original literature, and the scholarship of 



the book is worthy of the author and of the 

 university with which he is connected. 



Von Lippmann's " Addresses and other Con- 

 tributions to the History of the Natural Sci- 

 ences " is undoubtedly, in many ways, the most 

 interesting volume of the set. It is a reprint, 

 with slight alterations, of thirty-two addresses 

 and articles, written during the past fifteen 

 years, by the versatile director of the sugar 

 refinery of Halle. They are not fugitive 

 papers, but profound historical studies, and 

 their permanent value — evident enoixgh to the 

 reader — is shown by the frequency with which 

 they are quoted by other writers, like von 

 Meyer. They are perfect mines of informa- 

 tion and entertainment, and the thanks of all 

 interested in science, and of chemists in par- 

 ticular, is due to the author and publisher for 

 issuing the studies thus, in collected form. 

 The longer articles include systematic surveys 

 of the chemical knowledge of Pliny and 

 Dioskorides, a history of gmnpowder and fire- 

 arms, an abstract and critique of Goethe's 

 " Farbenlehre," and an analysis of Leonardo 

 da Vinci's many-sided attainments, as a man 

 of science and mechanics. In another, the 

 author makes a searching inquiry into Francis 

 Bacon's writings and mode of life, with a view 

 to determining the exact measure of the pro- 

 found knowledge often attributed to him and, 

 incidentally, to settle the question whether, if 

 Shakespeare himself lacked the education and 

 scholarship shown in the plays. Bacon was, 

 as some believe, the one man of that time who 

 obviously had the requisite qxialities, and 

 might therefore have been their author. Just 

 as in the earlier essays the author's extensive 

 reading in Latin, Greek and Mediaeval litera- 

 ture fills the reader with astonishment, so here 

 his familiarity with English literary, scien- 

 tific and philosophical writings is amazing. 

 He quotes, in passing, Harvey's remark, that 

 Bacon wrote, not like a scientific man, but 

 like a Lord Chancellor, and cites Carlyle, 

 Whewell, Mill and dozens of others with be- 

 wildering appositeness. The author is un- 

 doubtedly the Andrew Lang of science. This 

 article leads naturally to another containing 

 a systematic account of the scientific knowl- 



