August 31, 1900.] 



SCIENCE. 



343 



constricted at the base, and in preserved 

 material, showing no trace of pigment. 



Examination of stained specimens shows 

 that they apparently have the structure of 

 the lateral line organs described by Eisig 

 for the Capitellidse.* There is the same 

 arrangement of the nuclei, and the same 

 radiations extending from the center toward 

 the periphery (Fig. 2). Ko trace of cilia 

 could be seen on preserved material, and 

 the organ is apparently not capable of re- 

 traction into special sacks in the body wall. 

 The cuticle, also, is relatively more thick- 

 ened on the outside of the organ than is 

 represented by Eisig's figures. 



I am unable to give any details of the 

 finer anatomy of these organs. The ma- 

 terial at my disposal is not well enough 

 preserved for histological study, and macer- 

 ations and sections have thus far yielded 

 no results. My only excuse for presenting 

 this incomplete note is that while it is de- 

 sirable that the existence of the organ in 

 the group should be noted, there seems no 

 probability of securing more favorable ma- 

 terial. 



Aaron L. Tbeadwell. 



Marine Biological Laboeatoey, 

 Woods Holl, Aug. 10, 1900. 



SCIENTIFIC BOOKS. 

 An Outline of the Theory of Thermodynamics. By 

 Edgae Buckingham, Ph.D. (Leipzig), As- 

 sociate Professor of Physics and Physical 

 Chemistry in Bryn Mawr College. New 

 York, The Macmillan Co.; London, Macmil- 

 lan and Co., Limited. 1900. 14x22 cm. 

 Pp. xi + 205. 



In the preface of this newest book on thermo- 

 dynamic theory, the author states his aim in 

 the following words : " In the course of study- 

 ing thermodynamics I have found a considerable 

 gap between the text-books available and the 

 modem memoirs. This volume has been writ- 

 ten to spare other students some of the time 

 which I have had to spend in bridging over the 



* ' Fauna und Flora Golf es v. Neapel ' 16, p. 76, ei seq. 



gap for myself. As the title indicates, it is not 

 a book of applications, but a brief outline of 

 the theory, the applications having been selec- 

 ted solely with a view to their illustrative 

 value." The book is evidently intended for 

 the beginning student. 



The treatment begins with the necessary in- 

 troductory concepts, then takes up successively 

 the first and the second laws of thermodynam- 

 ics, and concludes with a discussion of the cri- 

 teria of thermodynamic equilibrium, and of the 

 phase rule. 



Under the first of these general heads appears 

 a lucid and brief chapter on thermometry, an 

 elaborate analysis of the idea of a quantity of 

 heat, and the statement that only systems that 

 have equations of equilibrium are to be con- 

 sidered. It is not emphasized, as it might well 

 have been, that a quantity of heat is a purely 

 auxiliary quantity, a convenient but wholly 

 arbitrary mathematical fiction. In connection 

 with the first law of thermodynamics, we find 

 a simple discussion of the law, an exposition of 

 the law of constant heat sums and of the rela- 

 tion between heat of reaction and temperature, 

 and a study of specific heats. A recapitulation 

 at this point completes the first half of the book. 



Passing to the second law of thermodynamics, 

 we are introduced to : reversible processes and 

 Carnot's theorem ; the ideas of absolute tem- 

 perature and of entropy, derived from the prop- 

 erties of ideal gases ; the combination of the two 

 laws, to yield the differential of the energy of a 

 system ; and Gibbs's fundamental equations, 

 which result from changing the independent 

 variables. This part of the book is completed 

 by an admirably clear and consistent account 

 of the theory of the porous-plug experiment, 

 and a number of simple illustrative applications 

 of the general theory. The final three chapters 

 are devoted mainly to the criteria of thermody- 

 namic equilibrium, and to the phase rule as ap- 

 plied to systems in which no chemical combina- 

 tion occurs. It is not made clear here that the 

 criteria of equilibrium are consequences of the 

 inductively reached principle of the spontaneous 

 dissipation of work availability. 



In all this. Professor Buckingham has done 

 pretty satisfactorily what he set out to do. The 

 subject-matter is well arranged ; the book is 



