NEW BOOKS The Elements of Physical Chemistry. By]. L . R.: l / o ~ ~ a nFivst . edifioz. 13 X 19 c u t ; pp. z i i i nizd 299. &Tew Y o i f k : ]oh?t lVilej# nizd So)zs, rS99. Pvice : cloth $2.00. - In the preface the author s a p : ‘ I The object of this book is to present the elements of t h e entire subject of Physical Cheniistry in one volume, together with the iinportant aiid but little knoivn applications of i t to t h e other branches of cheniistrq-. Many persons h a r e found i t difficult to obtain a comprehensive outline of the subject, owing to the length of time which i t has been necessary to spend upon the separate volunies devoted to special portions of it. To all such this rolutne may he of value. . . . The arrangement as well as the scope of the volume is tien-. which I think makes the subject more logical and clear.” The successive chapters are entitled : introductorl- remarks ; the gaseous state ; the liquid state : t n e solidstate ; solution ; the r81e of the ions in analytical cheniistry ; therrnocliemistry ; chemical change iequilibrium, then reaction velocity) : phases ; electrochemistry (migration of the ions. conductivity of electrolytes, electroniotive force, electrolysis and polarization). This classification does not differ materially from that adopted by S e r n s t . Therniocliemistry is placed before the niass l a v (Tvhich however is referred to in the second chapter) and the section in Kernst’s book entitled * ’ atom and niolecule” has been absorbed ; but otherwise there is not much change. The classification cannot he called a good one. Dissociating gases are a case of chemical equilibriuni but they are discussed early in the book, long before the niass law has been taken up. The boiling-point and freezing-point methods involve thermocheniical data and these latter are discussed two chapters later. The phase rule conies just before electrochemistry as in the first edition of Sernst‘s Theoi,etische Cheiuie. T h e influence of S e r n s t rather than of Ostwald is to he detected in the unfortunate prorninence of kinetic theory throughout the volume. This classification is no worse than those in other test-hooks and has much S on the part of physical chenithe same faults. There is a C U ~ ~ O Udisiiiclination ists to recognize the fact that their science hasgrown. S o one nowadays would junible together qualitative and quantitative analysis. taking up the quantitative determinations of one group before the qualitative tests for the second, yet n-e pride ourselves on doing just that thing in physical chemistry. TT‘e are bound to come sooner or later to a division of the subject into qualitative a n d quantitative physical chemistry. The qualitative phenomena will then he classed where they belong wider the phase rule and the theorem of 1,e Chatelier. The quantitative phenomena \ d l be classed where they belong under the mass law and the theorem of van ’t Hoff. The reviewer has a classification for quantitative physical chernistrj- which he has been testing for sewral years and which
lie helieves to have merits. The general arrangement is as follo\\-s. Son-electrolytes : mass law at constart temperature, thermoclieniistr~,change of equilihrium Tvith the temperature. Electrolytes : mass law at constant temperature, therniocliernistry~change of equilibriuni with the temperature. Reaction velocity at constant temperature and then Ivitli changing temperature in liomogeneous and iiihoniogeneous systems including cliffusion, vaporization and crystallization. 3liscellaneous, inclutling surface tension, etc. Electrochemistry. This classification is open to tlie criticism that it separates things that niiglit well come together : hut it has the advaiitages that each step folloivs naturally and logically from the preceding ones and that at no point is it necessary to presuppose what conies later. For these reasons the reviewer believes this classification, though by no means perfect, to he better than those of Ostwald, S e r n s t , vaii ’t Hoff, Speyers, and Morgan. Ti’hile the author is perfectly right in stating that there is a need for a work giving the general principles of physical chemistry in one volume, it seems as though lie had gone to the other extreme and attempted too great condensation. It is very difficult to compress the whole subject into less tlian three hundred small pages without making the treatment superficial. That one is prepared for : hut, in this particular volume, the errors of commission ani1 of omission occur on almost every page. On p . z we read : ‘ ‘ Energy is the power of doing work which a hotly possesseii by reason of its state.” On p. 6 we learn how to determine the atomic Tveiglit of lead when the atomic weight of oxygen is known ; hut why this latter should he 16 is not discnssed. Ii‘hen we get to p. I j we are told that “ t h e atomic weight of hytlrogen is assumed to he I , ” while 011 p. 16 we read : ‘‘ 111 orcler to preserve the relation between the molecular weight arid the deiisity, it is customary to calculate the latter as based upon an ideal gas. the weight of which is I 32 that of 0 . I n this way we avoid actually using hydrogen as a standard i n the esperinieiit.“ The development of the gas law on p . 1 2 is not clear. 011 p. 17 the correctioti for the liaronieter refers to readings in millimeters and not in centinieters as the t e s t implies. It is not correct to state, p. 25, that .Ivogadro’s law holtls in all cases where there is 110 dissociatioii. T h e author contratlicts this liiinself ten pages later. On p. z j the reader would get the impresaioii that chaiigiiig from pressures to coiicetitratioiis did not change the numerical value of the dissociation constant. C h i p. j j is the sentence : . ’ Should this kinetic energy of the niolecules he increased h y heat. then the attraction will be overcome anti the liquid goes into the gaseous state, i. e. it boils.” riiiler surface tensioii, p. 6 j , there is 110 reference to the questioii of a contact angle. Iliscussing Henry’s law$ p. j 6 . the author says : ’‘ The gas absorbed in this way is not to he considered as liquefied ; its molecules simply hecoxrie constituents of tlie liquid, just as :hose of the latter are constituents”. The calculation of the molecular weights of tion-miscible liqiiids from the vapor-pressures of the pure components cannot be applied. p. ‘79, to ‘ I all mixtures that form two layers“ nor is it true that “ t h e vapor-pressure is still equal to the sum of those of the t\vo layers.” I t is not true that equal amounts of each layer must distil over at aiiy one temperature.” Pfeffer, p. Sz,was not the first nian to notice that a colored solutivt~ diffuses into water until the mass is homogeiieous
nor \vas he tlie first to discover osmotic pressure. H e was the first man to make quantitative measurenients of osmotic pressure - a very different thing. 011p. 94 i t is unfortunate to select sodiurn chlorid as an instance of Ostxvaid’s dilution law. In discussing the relation between concentration and vapor-pressure it is nowhere brought out that 72 is expressed in terms of the molecular weight of tlie solute in the solution and S in terms of the molecular weight of the solvent i n the vapor. The reviewer ~ v o u l dsuggest a reference at this p i n t to the case of acetic acid. On p. 113 the sentence “Since the ice which separates is always pure solvent” should read ‘ ’ \Theti the ice which separates is pure solvent.” There is no reference at all to a rise of freezing-point due to solid solutions. On p . 129 there is the incorrect defiiiitioti : ” h saturated solution is one which coiitains the maximum anioutit of substance.” \\’heti discussing tlie dissociatio:i of hydriodic acid, p. 163, the experinietits of Lemoine are cited instead of those of Bodenstein. Commenting on the fact that t h e catalytic action of hydrogen is not strictly proportional to the conceiitration, the author says, p. 199 : there must be, then, another factor to he coiisidered, and this .lrrhenius found to he the presence of other ions which increase the catalytic action of those of H. This theory explains very simply the anomalous hehavior already mentioned”. Contrast this with tlie paragraph on the change of reaction velocity, with the temperature. p. 208, where no reference is made to the van ‘t Hoff formula. The deduction of the phase rule on p. 2 1 0 is inaccurate In the chapter on electrochetnistry the volt is defined. p. 2 I j , as 10 I I of the electromotive force of tlie Daniel1 cell. O n p. 216 Faraday’s law is expressed as follows : I ’ -111 movement of electricity i n electrolytes takes place only hj- the concurrent movement of the ions in such a way that equal aniounts ut’ electricitcause chemically equivalent amoutits of the different ions to move”. h good deal of pains has evidently heen spent on this definition atid yet it leads to the conclusion that the migration velocities are equal iti mixed solutions. The unit of conductivity is defined on p. 2 2 4 in reciprocal ohms : hut tlie migration velocities on p . 232 are referred to the conductivity of rnercury as unity. Or1 p . 2 j J the author ignores Helmholtz’s work on concentration cells. IVhen discussing tlie theory of the accumulator, p. 283,no reference is made to Liebenow’s plumbic acid theory and in the pages on polarization 110 reference is made to any work suhsequent to that of Le Rlaiic so that the true significance of the decornposition point ( p . 289) at 1.70 volts (1.67) is missed completely. These defects have heen pointed out at some length because these are errors that are i n no way a necessary c o n s e q u e ~ ~ cofe the plan of the book. It is not until these - and many others - are corrected that the usefulness of a hook conW i l d e r D.A n ?/ croft structerl on these lines can he discussed. Lectures on Theoretical and Physical Chemistry. By/. H . ~ Y Z I I‘ t H o f . ThimLanied by R. A . Leizfeldt. Part Z, Chciuica/ L l y i n m i c s . ‘5 X 22 titi I. Prirc : cloth zz shilliitjis. -There ~ 254 p p . Lo?ido?t: Edzxil?l A i w ~ l dzd93. has already been a notice of the German original ( 2 , 2j6) and of a French translation of this work I , Z , j 6 j ) . I t is with pleasure that I call attention to the Euglish translation. The general appearance of the work is good and the
translation has beeti well done. One ivoulrl have heen even more gratefill if the translator hart folioxeil the cxarriple of some other translators and had added ai1 intlex. I1 7iLdci.D. ~ ! ? ~ z i i c i ~ o f f
A Textbook of Inorganic Chemistry. By G. S. .Vewih. Fgfh E d i f i u n I. 13 X ' 9 C l i L ; flfl, X z ' ( Z 1 2 d 66!,. /\7ezLl y0l-k : ~ O l i g l ~ i n l / . 7GYCel2 . l Z l 7 i f C U . , '$97. Pri(e : $[,7j.-- There is, a>parently, an exteiisive de~nantl for Mr. S e i r t h ' s testhook of general chemistry : for a fifth edition is now out. The book is a liig one, and presents a iot of detail. Opinions m a y well differ 011 lioiv m u c h matter shoul(1 he provitled for t h e st.utly uf a heginner : h u t i t does seein to the reviewer that 6jo pages are too rnucli. The first thing to be attained shoultl be some sc,rt o f general viex of the sahject. iiot acquaintance with a mass of detailed illformation. In t h e many details. the general view is easily lost. The author h a s arrange@-his material ill three Parts. The first of these presents general considerations ; the second a study of hydrogen. o aiitl carbon : ani1 the third a s!-sternatic treatmeat of tlie eleiiie the periodic classification. 1 t results from this that w e have i i i niolecules, atoms, elenleiits and conipoun(ls, chemical affinitv, ralence, gzs theory, dissociation, electrolysis, the periodic system, evaporation and ftisiull. solutions. therrnocliernistr!., etc., for a hundred and fifty pages. Ixfdre we begin to find a serious statement of elementary facts about the air, conihustioti, n-ater, and the like, SOK this is too hati. . h t l it may \veil he questioiied whether it is wise to set out, i n a treatise 011 a science of facts. with t h e cio,qrnatic statement that ' matter' is to be regarileti as ag,qregations of tnolecules. Chemical facts, and t h e actual content of the molecular theory (which has, really, nothing to d o with t h c r e t e ' molecules' I, and the meaning of t h e combining \\-eights of elements. can all he clearly and s i m p l - put without etitangliitg them in a network of hypotheses that are .xdepetidetit of them. .iiicl a hetter arrangemcmt of the material. t h e reviewer thinks, could he attained hy presenting the sigiiificaiit experimental and theoretical - not hypothetical - facts of tlie science in the natural order in xhich these elements of the matter ha\-e heen discovered. The development of the cheinical kno\vlecl,qe of t h e individual wouid then become an epitome of the actual historical development of the suhject : and this knowletlge would be far more e.isil?- grasped antl assimilated than can possibly he t h e case \\-hen the suhject is presented in any less natural way. I t should, furtherrriore, he easy to see that the act:ial facts antl relationships to he learned can he easier and hetter learned when they are kept free, at least at the l)eginiiing, of perverse statements \r-hich the stater hitiiself does not try to prove. Clifford, \rho said trlatiy true things. never said a truer one than that no one shoulil he asked to believe a thing utitil he is in position to appreciate the evidence for it. Traite d' Analyse chimiyue quantitative par 1' Electrolyse. /?j,J . R i b i i i . 16 x z j r m ; p p . :ni and 3o.f. Paris: .llnssoii et Cie, ~ ~ 2 9 9 .f'rirc: p t r p e ~p. f i z 2 ~ i c . s -The . hook is divided into four sections, the first devotetl t o general theory a n d apparatus. the s,econd to the cleterniination of single metals or metalloids 11)- electralysis, tlie third to t h e separatiou of tlie metals and tlie fourth to special teciiiiical p;ohleins. In the appendix there is a wries of L I X ~ L I I
238 tahles though one regrets to see that the atomic weight of oxvgen is taken as 15.96. The hook is by far the best Ivork that hasappeared in French and could be recominended highly were it not for the fact that practically 110 references are given. Such recent work as that of Kuster and v. Steinwehr is cited in the t e s t and the author shows familiarity with the work that has been done in Germany a n d in Xinerica. This volume m a - he welcomed as another sign that the scientific isolation of France in chemical matters \rill soon he a question of the past. The historian of the future will record that physical chemistry in the hands of Raoult, Le Chatelier and Duheni has been the leaven.
IViider D . Batici,oft The Spirit of Organic Chemistry. B-v A 1 - t h w Larhirzan. 13 x r9 c m ; nud 229. -Yew York : The r7Ztrr?itil/cin Compaiiy, 1899. Price : $1.50.-This little volume consists of a series of sketches. each sketch showing the historical deveiopnient of some problem or group of prohlenls in organic chemistry. The suhjects treated are : the constitution of rosaniline ; Perkin's reaction : the constitution of beiizeiie : the constitution of acetoacetic ether ; the uric acids group ; the constitution of the sugars ; the isomerism of maleic and fumaric acids : the isonierisni of the oximes ; the coiistitution of the diazo compounds. This list shows that the suhjects have been x e l l chosen. The treatment is good. barring a xnisguidetl conscientiousness i n splitting infinitives ; and the volume is a very interesting one. There is a real neet1 for hooksof this general type and it is to he hoped that i t xi11 not be long hefore we have a fullfledged literature of critical historical studies. Practically the only criticism that the reviewer has to make is that it ~ r o u l dhave heen hetter to state more explicitly the facts \vhicli a hypothesis of niultirotation must explain in order to he accepted. Incidentally, it would also he well to onlit the inaccurate statement, p. 11s: ' ' Recent investigations show, however, that the molecular Treight of the dissolved sugar in its initial and final coiiditions of rotation is one a n d the same, n-hich fact precludes the addition hypothesis." The author has given references copiousl- throughout the t e s t : and has added both a subject ani1 a name index. for xliich all readers will he gratefulto him. There is also a sis-page introduction hy Freer. W i l d e r D.Raizcroft
pfi. rt-viii
Harper's Scientific Memoirs. 14 X 21 c i i t . AVew York : H a r p e r nud Bvo1hei.s. 1899..Vo. r , The Free E.a-pa?lsioz of Gases. By Gay-Lrissac, Ioiile, aitd Joiilc niid T ~ ~ I ~ SEdited O I L 6311. . S. A w e s . 106pp. Price: 7 j ceiits. i'v;o. 2. Pt,isiiiatic oiid Difrnctimt Spectr-a. By Joseph uon Fmziizltofev. E d i t e d by /. S.A m e s . 68 pp. Price : 6 0 reiits. 3. Roiitgeit Rays. By Roittgeit, Stokes, aiadJ.]. Tho~~rsora.E d i t e d by George t? earker. 76 p p . iVo. 4 , The AZodent Theory of Solratiolt. By Pfefci,, vnlt ' t Hof, Arr*/ieiziiLs, aud Kaoult. Edited by H . C./o?ies. 134 pp. We greet x i t h pleasure the beginning, in English, of a series of reprints and translations of classic scientific papers, analogous to Ostwaltl's justly valued A'lassikev series. The general editor is Joseph S. Xmes, of the Johtis Hopkins
A'ew Rooks
239
LTiiiversity, and he has secured the collaboration of a number of well known American nien of science. Each of the little volumes is to contain a complete paper, or, in sonie cases, a collection of shorter papers, on some subject. Xotes, explanations, and corrections are to he added when needed. In each case a synopsis of the present state of knowledge of the subject, together with a l~il~liography and an index, is to close the whole. Fonr volumes are nom out. The first, on the Free Expansion of Gases, contains the familiar papers by Gay-Lussac. Joule, and Thornson and Joule on this ahsorbing therrnodynaniic topic. Tralislati~nand editing h a r e been done by the general editor. The second, likenise mlited by Mr. Arnes, gi\-es a cycle of papers by Fraunliofer. cmn prismatic and diffraction spectra. The third, edited by George F. Barker, presents papers hi- Rontgen, Stokes, and J. J . 'Thornson, 011 the Rontgen rays : while the fourth is made u p of a series of the nieirioirs of Pfeffer, van 't Huff, Xrrhenius, and Raoult, on the llodern Theory o f Solutions. This last volume is edited by Harry C. Jones. I t is a most admirable one. .It contains selected passages from Pfeffer's osmotic investigations, vaii' t Hoff's paper on the analogy betweell gases and solutioris, ilrrhenius's article develop:ng the theor?. of electrolytic dissociation, and three papers hy Raoult. I t is a pity that one more paper had not been added : that of Raoult and Recoura, discussed hy van 't Hoff, Zeit. phys. Chern. 5 , 423 ( ~ S g o ) . Brief biographical sketches of Pfeffer, Arrhenius, van 't Hoff and Raoult have been supplied by the editor. This is an excellent idea : but in the case of Raoult, this has been carried out in such a way that: the reader gets the impression that Raoult had never done anything of importance outside of his vapor-pressure studies. I n the biography of van 't Hoff it is not clear why the work on active oxygen ~~hoL~ld. not have heeii mentioned. These points are not of great iniportance, i,iiice the real value of the hook consists in the translated papers ; and this arrangement accoriiing to subjects is a very welcotrie one. I n a n appendix there is a partial bibliography of usniotic pressure, theory of solution, freezing-point and boiling-point methods. This does not claim to be complete, the editor intending to cite only the more important papers. Even after this reservation one does not quite understand how Naccari's work came to be ornitteci ; and if 1,ord Kelvin's criticism of the ositiotic pressure theory is to be cited, the answer hy Gibhs should not have been ignored. Very interesting further \,olurnes of the series are announced as in preparation. Sotahle among these are nuriibers that are to treat the laws of gases, the second law of therniodynan~ics,electrolytic conductioii, the law of gravitation. the Faraday and Zeenlan effects. and the wave theory of light. Editon Muller-Pouillet's Lehrbuch der Physik und Meteorologie. ,5:v L . Pf(rirndZt7r 0. L71?tl?ncr. 1'Ol. 21, Fff1.t 2. f 4 , 5 X 2 2 . j C l l l ). pfi. x i v aild 76s. ~ ' I - ~ I L I ~ s c ~F.z LVi~ti cii ~i~r :wid S o h n , 1898. Pcice :pnpe?*ro~rzar,ks.-12liillerPouillet's well-known Lehrbuch is now appearing in its ninth edition. Of its r'ifferent Parts, the one that ~cotitaiiismost having a physlcochenlical interest is. naturally, the second part of Vol. II., on Heat. This portion of the work has hseen almost wholly remitten ; and much new material has therehy been incorU7ld
porated in it, notahly sectiotis on tlie theory of solutions. and on the Gihhsian phase rule. I t is. indeed, a gratifying indication of progress, to find eight pages devoted to the phase rule. The closing reference here to IlIeyerhoffer's little hook might, hoxever, have heen replaced to advantage by a citation of Bancroft's far more comprehensive treatise oil the same subject. Thermometry, as a matter of course. introduces the present volume. This snbject is followed by chapters on fusion and vaporization, calorimetry, therrnochemistry. thermodynamics, kinetic theory, conduction and radiation, and meteorology. The whole Irork is priniarily a treatise 011 experimental physics : theory appears in it only in so far as has apparently been deemed unavoirlahie. I t is profusely illustrated h>-xvood cuts, and is supplied with an index.
1,E . 7i.evor Kurzer Abriss der Elektricitat. B y L . GI-net=. 16 x 23 cin; p p . nird 180. Stitffgai,t: J . E?tg+eL/to~it, 1897. PI.ice : cloth 3 iiinrks. -The present little volume is a digest of Graetz's larger work on electricity. a hook xvhicli has Tone through many editions. I t is a popular treatise, intended to give in simple form a coherent account of the more important electric phenomena, and of the views that are currently held in regard to thein. The niost prominent peculiarities of the book are, perhaps, the order of treatmeut that is pursued in it, -the production and properties of electric currents being studied before electrostatic phenomena are taken up, - and a consistent attempt to represent all electric phenomena as changes in the stateof the ' ether '. Concerning this latter point, tlie author remarks that although a \vholly satisfactory ether theory does not exist, yet electric processes can be easily visualized as processes in the ether. and many of them, as for example electric oscillations, hecome therehy especially intelligihle. Throughout the book. further, the presentation of scientific facts is always accompanied by an account of the more important technical applications that are made of thein. The topics treated in the volume are. successively : the production of currents : the laws to Tvhich currents are suhject ; niagiietic effects of currents : electrostatics ; dynamos : the relations of currents to thermal, optic, aud chemical processes ; conduction hy gases ; electric waves. This is a comprehensive programme, and it is simply, clearly, and scientificall- carried through. E l i
/. E . T?*evor On the S t u d y and Difficulties of Mathematics. Bj' Az~gmtzisDe ;?l'a,-gii?z. z + X 20 C I I ZI. p p . v i a i d 283. Chicago : Zhe Opeiz CON?^ Pub- 2 2 ~Eiiifiou. 1 l i s h t z g Coiizpnizy, ~ 8 9 8 . - Of the instructive publications of the progressive Open Court Cotnpanj-. one o f the most recent is an attractive reprint of De Morgan's little treatise on the Study and Difficulties of Illathematics. , it has long been practically inDe Llorgaii issued the original work in I S ~ I and accessible. As a sensible ant1 lucid commentary 011 the principles of arithmetic, algebra. geometry. and trigonometry, it cannot easily he surpassed. The author says that his object has been " to notice particularly several points in the principles of algebra and geometry. which have not obtained their due importance in our elementary works on these sciences." The way in which this has been done is ample justification for reproducing the work now. The editor of
t h e present edition, X r , Thomas J. McCormack, sa>-s, \-cry justly, that De Morgan. though taking higher rank as an original inquirer than either Huxley or Tyndali, was the peer aiid lineal precursor of these great expositors of science. and he applied t o 11:s Iifeloiig task a n historical equipment and a psychological insight which 1iaT-e not yet borne their full educational fruit. .Itid nowhere have these distinguished qualities been displayed to greater advantage than ill the present work, which x i s conceived and written 75-ith the full natural freedom. and with all the fire, of youthful genius.” J . E. T r c a o ~ ”
The Arithmetic of Chemistry. By j o h i z LVcrda’elL. r2 X iS c i u ;$$. viii aiid 133. - 1 - e ~ YorR : The .7facinillaii Co?~z$aiiy,zS99. Pn’rc: cloth, 90 ctirts. -In the preface to this prohleni hook, the author says : ’ * The form that this book has taken is due to a very considerable experience of the clificulties encountered by students when attenipting to make clieniical calculations. The effort has heen made to smo-are accompanied hy a tiumber of problems for practice. These prohlerns have been taken from the examination papers of various British and Xrnerican J. E. T ~ P Z ~ O Y universities The Metaphysic of Experience. By Shadworth H.Hodgsoiz. r j x z r l’ol Z. x x nizd 459 $$. ; Vol.ZZ. 403 p j . ; V o l . ZZZ. 446 p$. ; L70L. ZV, s. a m i CO. Price: $iz.oo.- JIr. Shad503 jj. A’\7eTilYorR: L o i ~ g v z n i ~Grecii worth Hodgson, for fourteen years President of the .lristoteliaii Society, presents in four sumptuous volunies the results of the lahor of eighteen years devoted to framing the outlines of a complete system of philosophy. His fundamental idea is that analysis of actual experience, avoiding assumptions, is the only trustworthy guide iii developing a conception of the nature of the universe. I t readily appears that all knowing is consciousness ; hut it does tiot folloiv froni this that coiisciousness is the only existence of which we have evidence. From the experience that gives rise to the conception of real conditions possessing operative agency, it is concluded that there is a n existence n-hich is not consciousness. and which exists whether perceived or tiot. This existence, termed physical matter in contradistinction to percept-matter, constitutes the subject upon which consciousiiess. as an existent, is con~iitionerl: it is the real condition of the arising of the special states of consciousness. .kid, finally, still froin the analysis of experience, Jfr. Hodgson is led to infer the existelice of an unseen world, which forms, together with the seen world, an infinite universe adequately known in one ceaseless nioment of awareness 1))- an omniscient Percipient. The work thus ends in laying the foundation of a theology. The t e s t is divided into four hooks ; of which the first contains the general CIJI.
analysis of experience ; the second a study of the connection between the positil-e sciences and philosophy ; the third an analysis of conscious action, leading to establishnieiit of the foundations of logic, aesthetics. and ethics ; while the fourth has to do with the Real Yniverse. I t cannot well be denied that X r . Hodgsoii has produced here a notable work. J . E. Trevor Annuaire pour 1’ an 1899, publie par le Bureau des Longitudes. 9 x 15 mc, p p . v atid 653. Paifis : G n u f h i e v -L’ilkars et Fils. Pvice : 1.50f~arzcs.- That reliable data hook, the Arznzrnil-e of the Bureau des Lorzgitudes, is now out for 1899. I t contains the usual collection of astronomical. physical. and chemical data ; arid four appendices, the most important of which is a n account, by 11. Gautier, of the great siderostatic telescope he is building for the coming Exposition. The thing has a n object-glass of nearly fifty inches (1.25 m ) dianieter, and a focal length of nearly 2 0 0 feet (60 meters). It is, thus, one quarter larger than the Perkes glass. It is, hovever, to be fed by a huge mirror, which must occasion a great loss of light. J . E . Tveuov
