July 14, 1892J 



NA rURE 



245 



more that is indispensable to teaching the minor arts as 

 a system even to the youngest children. Nor does Mr. 

 Barter mention the so-called Venetian intarsiatura, in 

 which the pattern, drawn on one'piece of wood, is cut half 

 through the panel, the line being then filled with coloured 

 mastic, and the pattern dyed. But such sins of omission 

 are trifling, though in a book which proclaims on its title 

 that it is devoted to wood-work we should have expected 

 something more than carpentry, and at least a full des- 

 cription of Slojd carving. And having pointed out, as in 

 conscience bound, every defect, we feel it to be a duty to 

 congratulate the publishers of this remarkably handsome, 

 well- bound, and useful work on having done their best, 

 and on having issued a manual which deserves a place in 

 every industrial school. 



But there is a word to be said as regards the preface 

 and a portion of the introduction. It is perfectly true 

 that manual instruction for children develops thdr 

 intellects, and fits them for life far more than ordinary 

 school studies usually do. But it is not true that this 

 training should consist, as Messrs. Ricks and Barter 

 virtually declare, of nothing but Slojd, be it Swedish or 

 English, or of carpenters' work. Such training should be 

 for girls as well as boys, and it should be based on design 

 and drawing, taught simultaneously in the simplest and 

 easiest freehand ; after which the pupils may take up not 

 merely carpentry, or even Slojd — which is nothing 

 efifectively but a minor branch of wood-carving — but also 

 wood-carving itself, and many other arts, all of which 

 come as one and promptly to the pupil who can design^ 

 and, when occasion favours, also can model a little. But 

 to expect that carpentry alone, without a trace of art, is 

 all that is needed to inspire the creative faculty is a great 

 mistake ; and what is worse is that, despite thousands of 

 living examples of the superiority of the more artistic 

 method for children, the British — like the American — 

 public persists in believing that all that is needed is to 

 teach " our boys " how to make benches and boxes. 



OUR BOOK SHELF. 



Thermodynamische Studien. Von J. Willard Gibbs, 

 iibersetzt von W. Ostwald. (Leipzig: Engelmann,i892.) 

 This is a German translation of three of Prof. Gibbs's 

 Thermodynamic Papers. These were published during 

 the years 1873-8, in the Transactions of the Connecticut 

 Academy (vols. ii. and iii.) ; and one reason which 

 prompted Prof. Ostwald to undertake the translation of 

 them was their inaccessibility to the general scientific 

 public. Their importance is sufficiently attested by the 

 fact that part of the ground covered by Prof. Gibbs has 

 been gone over again by later writers who deemed they 

 were themselves pioneers. 



" Graphical Methods in the Thermodynamics of 

 Fluids" is the title of the first paper. It gives for the first 

 time a general account of the comparative advantages of 

 using various pairs of the five fundamental thermody- 

 namic quantities for graphical representation. The 

 entropy-temperature and entropy-volume diagrams are 

 discussed in considerable detail. The second paper con- 

 tains the description of the volume-energy-entropy sur- 

 face, which generally goes by the name of Gibbs's 

 thermodynamic surface. Its contents are familiar to all 

 who have studied Maxwell's " Theory of Heat." 



NO. I 185. VOL. 46] 



The third paper, " On the Equilibrium of Heterogeneous 

 Substances," fills five-sixths (344 pages) of the whole 

 book, and is, out of question, by far the weightiest con- 

 tribution which Prof. Gibbs has made to the development 

 of thermodynamic methods. To him must be given the 

 credit of first formulating the energy-entropy criterion of 

 equilibrium and stability, and developing it in a form 

 applicable to the complicated problems of dissociation. 

 To give anything like a complete idea of the contents of 

 this paper, with its discussion of critical points, capil- 

 larity, growth of crystals, electromotive force, &c., would 

 mean the reproduction of Prof. Gibbs's own very full 

 synopsis, which in the German translation forms the 

 greater part of the table of contents of the book. It will 

 suffice to notice the general theory of the voltaic cell, 

 with which the paper ends. Here distinctly for the first 

 time is it pointed out that the electromotive force of the 

 cell depends on other factors than the variations of its 

 energy. Von Helmholtz's theory, which differs from that 

 given by Prof. Gibbs only in the greater fulness of detail, 

 was not published till 1882. 



Prof. Ostwald tells us that he had the benefit of the 

 author's revision. With the exception of a few obvious 

 corrections the original papers are most faithfully repro- 

 duced, even to certain footnotes which in these days have 

 no particular value. In the circumstances a little license 

 might well have been taken, and a slavish adherence to 

 the original text departed from. For example, it is surely 

 most desirable to use the word isenergic for lines of equal 

 energy, and not the inappropriate term isodynamic which 

 Prof. Gibbs made use of in his paper of 1873. Again, 

 we question the right of any writer on thermodynamics 

 to use the word reversible in other than Carnot's sense. 

 Such double meanings tend to produce confusion, in 

 spite of elaborate footnotes. 



These blemishes apart, however, there is no doubt that 

 Prof. Ostwald deserves great credit for his labour of love 

 in preparing this translation. He has made it possible 

 for the many, who know of Prof. Gibbs's work only at 

 second hand, to acquaint themselves with the original 

 papers, and we feel confident that the book will find its 

 place on the shelves of all who desire a really complete 

 library of thermodynamic literature. 



Elements of Physic. By C. E. Fessenden. (London : 



Macmillan and Co., 1892.) 

 The subject matter of this book is arranged in four 

 chapters— Matter and its Properties, Kinematics, Dyna- 

 mics (including statics, hydrostatics, and pneumatics), and 

 Heat. It thus forms an excellent introduction to a more 

 extended study of physical science. The treatment of 

 the subject is based largely on simple experiments to be 

 performed by the student himself, whose reasoning powers 

 the author seeks to draw out as far as possible by sugges- 

 tive questions interspersed through the text. The 

 following example will give a good idea of the style of 

 treatment : — 



"... All experience teaches that no two portions of 

 matter can occupy the same space at the same time. 

 This property which matter possesses of excluding other 

 matter from its own space, is called impenetrability. It 

 is peculiar to matter, nothing else possesses it. These 

 facts being known, let us proceed to put certain interroga- 

 tions to nature. Is air matter? Is a vessel full of air a 

 vessel full of nothing 1 Is it ' empty ' ? Can inatter exist 

 in an invisible state ? 



" Experifnent i.— Float a cork on a surface of water, 

 cover it with a tumbler, or tall glass jar, and thrust the 

 glass vessel, mouth downward, into the water. . . . State 

 how the experiment answers each of the above questions 

 and what evidence it furnishes that air is matter, or, at 

 least, that air is like matter. 



" Experiment 2. — Hold a test tube for a minute over the 



