TIME, KNOWLEDGE, AND THE NEBULAE
etc., the author has been able to put into 745 p i l e s n amazing amount of chemical fact and theory, presented in a thoughtful Martin Johnson, Fellow of the Institute of Physics and of the and thought-provoking manner and in a style which is easy to Royal Astronomical Society. Dover Puhlicationa, New Yark, 1947. read and ambiguous, 189 pp. 14.5 X 22 om. $2.75. Numerous topics not often found in general chemistry texts Of the volume is described as, ',A,, intro- am introduced and discussed in a manner celculated to hold the T~~ duction to the meanings of ~i~~ in physics, astromony, and interest of the superior student. In the earlier chapters certain of these sections are marked so that they may be omitted if dophilosophy, and the relativities of Einstein and of Milne." ~h~ consist or three pa*s and twoappendices, part sired without disturbing the continuity of the development. The I involves a general discussion of physical notions of ~ i ~ mala1 ~ heat, capacities of g m s a t constant pressure and a t con-the limitrutions to profitable between physics and phi- stant volume are brought in, and the relation between the ratio of these specific in ~ ~ ~views~of t ~ . ~ heats i and~ the velocity ~ ~ of sound ~ i a gas ~ is mentioned. losophy,v part 11 deals with the ~ (From the point of view of the beginner this discussion might be between timo and space, the displacement of lines as oberved in the distant nebulsR and of ~ i l ~clearer ~ sif the ~ units used in expressing heat capscities were made more definite. Even in the discussion of the law of Dulong and interpreta+,ion of &ese from a new point, of vieh., 165, the heat capacity of most solid crystalline elea discussion f, the notions ~ part 111 i win ~ Petit~ on page , to 6.4-numbers the physical and mental sciences, in metaphysics, and in theory of ments is stated to be scientific knowledge." In Appendix One sorne of the fundrtmen- units involved are explained sepmately.) Other topics which arc pn:sented in distinguish this text are: viscosity; surface tension; the hydrotsl in atomic and gen bond; the development of crystal forces; and, under nuolcar nonmathemat,icttl form, while Appendix T~~ deds \.it,h '.tho chemistry, the reactions leading to the preparation of the atomic of spiral nebnapplication of Milno's timcaealos to the structllre bomb. In the appendix arc found disoussions of units and dihe." with suggestions concerning the derivation of units and to ~ ~to l\lilne,~ dynmical ~ or tirne ~ is proportionsl d i the mensions, ~ ~ ~ ~ picture ~ of~inter-, t,he cancellation of dimensions-material usually omitted entirely logarithm of knemrttic or t time, H from an elementary book, but important enough t o have justified thC one .time as equally spaced ,.il be oomparahlc in a more prominent position. with intervabof decreasing size a n thoather scale, so that in theend its The principles of electrochemistry are used freely throughout an infinite number of such intervals on one scale would be needed an the other." I,, termsof the book, and the entire chapter on electrochemistry might have to correspond to the final unit it is possible to account been transferred to an earlier position instead of being left in its thig difference between the 1and scalclos traditional place among the metals. Twenty-one pages an: defor both t,he spiral form of the U ~ ~ U as I ~ dC l their apparent recession. The explanation offered for this observation is that voted to this chap* and a great range of topics is discussed. the 6rradbtion from distant nebulrte emitted Rufficientlylong ago is However, since all too frequently even students with a year of being intercepted terrestrially by material ,,,hose &toms have physics hehind them are puzzled by eleetrochemicd concept,s,the chapter could be improved by further elaborat,ion. Some of the advanced in frequency on the scale, so that the incoming illustrations relating t o electrochemical processes could be made trum appears shifted towards red or lower frequency." charer; far example, the diagram of thc Vorce cell (P. 236) does This is indood a novel point of view and the reviewer mlmt fess to a certain difficulty in comprehending both the logic by not. indicate that the electrolyte c61nes into contact with the cathode a t all. which it has been deduced and the couolusions. Many sections have been completely rewritten for this second To those not familiar rrit,h such mathematician philosophers as nq,itellead, the discussion by the author, while extremely logical edition. The topic of hydrolysis has been combined with ionic equilibria and expmded into a n imporbant chapter of 30 pages. and stimulat,iting, will undoubtedly prove not a t all easy H ~ those readeders ~ ,,,ha ~ may ~be interested ~ in ~~ i l,views ~ ~ Topios ' ~ covered in this chapter include the electronic theory bf and their relation to ~ i ~ ~theory t ~ will i find ~ r in ~the present mid8 and bases, conjugxte acids and bases, buffers, the acid exof a topic which has ponent (pK), and indicator tables with the pH range of the color volurnc 9. relatively simplified changes. This chapter could d l be consulted by students in hitherto rocdved attent,ion only in highly theoretical qualitative analysis for s clear and interesting exposition of topics SAUL DUSHMAN usually postponed to the second year. The symbol pH is stated G m s n n b EGECTR~C COMPANY in a footnote to imply that the hydrogen ion indexis measured by S C ~ N E O T ANEW D T . YORH t,he potential of a hydrogen electrode; the student may be puzzled by this statement since considerable space is devoted t o colqrimetric methods, and sinoe the pK is introduced without reference to 0 FUNDAMENTAL CHEMISTRY: AN ELEMENTARY TEXTBOOK FOR COLLEGE CLASSES Very few ambiguities are found in.the text. However, water &,roce G. ~ ~professor ~ of chemistry, i ~university ~ of ,is statcd on page 389 to be present in unit concentration in dilute ~ ~ b john ~ wileY ~ ~ sons, k ~ . N~~ york, 1947, nvi + solutions, a confusing statement sinoe the units for expressing 745 pp. 14 X 21 cm. $4. concentrations have just been defined as moles per liter. On page 225 the word "salt" is declared to have been made somewhat T m s IS a book intended for the intelligent student who is ambiguous by developments of the last few years. The term is planning a career in science. The contents, especially those not entirely elarified in this text, since on page 162 Al+++ is dealing with the theoretical aspects of chemistry, are covered so mentioned as a cation with B triple charge; later (p. 284) it is comprehensively that the book will be appreciated not only as a pointed out that aluminum chloride has the formula .41sClr, and text but as a book to review when the student is engaged in more that it is a isavdent compound; while on page 225 this substance advancad study. Indeed, by omitting obsolete or historical ma- is called a nonionic salt. On page 95 it is strongly implied that terial, "anecdotes about the alchemists, lists of formulas and acetic acid forms insoluble salts with metals, and this idea is reinequations t o be memorized, meaningless lists of properties and forced by a question in the exercises s t the end of the chapter. uses, superficial descriptions of antiquated industrial processes," The general appearance of the hook is attractive, and it is 118 0
