REVIEWS
Ct,neml On a possible change of weight in chemical reactions. F',.%??yoid nniz' .l/is.i L. E . Ray. Ph-j,.~.Rrie 5 , 247 ( 1 8 9 7 ) ~ Itispireti hy 1,andolt's work. Zeit. pliys. Clieni. 12, I ( 1S9;). the authors have studied the reduction of silver frorii an aninioiiiacd solution of the oxid by means of grape sugar. In two series there is an apparent loss of weight arid iri three there is an apparent increase. The largest variation is o.oS m g in a total weight of one hundred and twent>.-oiie granis. The probable error as given b y the authors seems to be a niatheinatical fiction quite del-oid of significance. It'. h'.
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A new method of determining the specific heats of liquids. R. L . L i i r h . Ph?ls. Rezi. 5 , z8r (1897). A current is passed through a coil placed in a vessel containing the liquid to be studied. The temperature is kept constant by rutinirig in more of the same liquid from a vessel in which it is kept at a constant lower temperature. \Theti the mass of liquid dropped, the difference of ternperature. the current, the resistance aiid the triechatiical equivalent of heat are known, the specific heat of the liquid can be calculated. By passing the sariie current through two calorimeters containing different liquids. tlie niechanical equivalent of heat cart he eliminated from the equation.
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The atomic mass of tungsten. ?E/. L.Nardiii. J o u r . Am.Chcm. Soc 19, 657 (16g7). Tlie conclusion drawn from a careful study of tlie subject is that the reduction of tungsten tnosid to tungsten is a reaction which is valueless for the purpose of detertiiiiiiiig the combining weight of tungsten. W. D .6. On a constant temperature bath. A . G o u y . Jour. de Pitys. (3)6,479 ( 1397 1 , The hath is so surrounded by non-coiiductilig material that the fall of tetrlperature is 0 . 0 0 2 ~ per niitiute for a temperature difference of 15" hettveen the 1,ath anti the room. The bath is heated by an incandescent lanip placed in a klrass tuhe. The current is regulated hy an alcohol-mercury thennostat. To avoid errors due to changes in the foMi of the mercury meniscus, the u-ire tvhich completes the contact is ciade to oscillate vertically. I t is said to he easy to if the barometer reniains co11keep the temperature constant to within o.000~~ stant. -1change of one centimeter of niercury in the barometric pressure means
a difference of o.mro owing to the coni:iressiliilit)- of the alcohol. The hath itself lloltls ahoiit one liuiitlretl liters antl a current of three niilliainperes is said
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to be sufficient.
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Heat and cold regulator. C. Richfcr.. ElektrociLeIiL. Zeit.4, 155 (rS57'1. The expansion of air forces u p a mercury thread. closing an electric circuit antl cuttiiig off the supply of gas. The apparatus can he obtained frotn C . Richter of Berlin. l17. D . E . O//t'-Cul/~I)u//ClLt SII'Sff'll2S
Stereochemistry of the phenylnitrocinnamic acids. -11.L'trkrr72i7z. Gnz-. Ifnl. 27, 11,-74 1 /Sy/ 1. There are three isomeric iiitrophei~ylcinnarliiic acids. anel each occurs i n two ci-!-stalliiie tnotlifications. 'rile ineta acid lias lieen stuclietl tlie iiiost tl~orougiil!- because it is the easiest to make. Seitlier iiiodification changes into the other in the tlark. Esposeil to direct sunliglit e:ich rnotlificntion cliniiges to a litiiitetf extent iiito tlie other \\-hen in solution. *. l h e rate of change is affectetl liy the preseiice of iodiii or of carbon. and it is proposed to stutlJ- this action more i i i tletail. TI'. D . E . c./iiiu.
Relations between the chemical composition and some physical properties of liquids. E . i ' c ~ Ai t~ I L O E I Joiir.. . dr P/ZJ,S. 13)6,5.3' (2897 I . Colson lias statetl have nearly itleiitical coefiicieiits of expansion. -1 referLanilolt aintl I3iiriisteiii sliows this riot to he the case. The replaceinrnt of liytlrogen or l i y ~ l r o s y l1 i ~ -chloriii, 1)roiiliii or iotliii clitninislies tlie contluctivit- for heat. the apecific heat anti the lieat of vaporization : hut illcrenses the density. 111 all these case.; the introduction of iotliii causes the most cliang:.- antl that of cliloriii the least. On passing from a fatty acid to the corresponcliiig alcohol, tlie tleiisity antl coiicluctii-it)- decrease xvliile the specific heat and the heat of vaporization increase. li'. D . n.
On the volume of vapor produced by evaporating one cubic centimeter of a liquid a t its boiling-point. J . ' 4 . G x ~ s h n n s . I l i ' c d . Z ? I Z ~ Z . 61, 780 (15'97). -1. 3Iasson has sIion.1i that a 1-oluiiie of oiie graiii of vapor at the hoiliiig point is approxiinatel>-the siiiiie for ineinhers of sitiall groups of closely relateil liotlies. E . f i . tlie lidoit1 tiioiio-suhstituticiii proilucts of 1)eiizt.ne. The author coinhiiies this rclatioii with his " tlieoreiri of correspotitliiig tetiiperatures " and ohtailis this forriiu1;i for substances contaiiiiiig C,H ant1 0 :-
ilenotiiig the tleiisity of the liquid at its t i o i l i ~ ~point, g 1%the nuniher of atoms in the molrcule. antl .I- a n-hole nutnlier or simple fraction ( I , 741 'I. In the esaniples quoted, the ' coiistaiit ' varies from 21 to 24 for ethers, from 29 to 6 j TI'. L..ll. for alcohols. ani1 from 36 to 4; for acids.
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Further application of the method of approximations to Maxwell's theory of gases. N.KeiLizdo?;J. .Sit:zo;,y.shJ*. A 4 k a d . 16'i~s. IZ7ieu, 105, ( I I AI 646 I i890 I . -1nioiig the greatest lieautie:; of 3laxmAl's theor>- of gases is the iriethotl h - which the hytiroilynaiiiic equations are clecluced. Beginning with a general fmnctional equatioii. 1\Iaswell obtains the ordinary hydrotl~-narnical ' I
equations hy specializing the functioii anti neglecting all terms but those of the highest order. If, however. terms of the next order he taken into consicleratioii the equations for friction and for conduction of heat appear of thenisel\-es. I t is. consequently. of great interest to extend the same approximate calculation to inclutle terms of still loir-er orders ; the possibility that the results rriight lead to the discovery of lien- facts i i aloiie sufficient inducement : although, consicleriiig tlie arhitrarJ- nature of tlie fuiiclainental hypotheses. a n accurate agreenieiAt lietn-een theory and experiment caii hartlly he anticipated. ' ' The ' arbitrary hypotheses ' referred to are the kinetic theory, Tritli the special assumptions that the . gas is rrionatoniic, the rriolecules are material points Ti-liicli repel one aiiotlier with a force reciprocally proportional to the fifth pocer of the distance, a n d the external forces acting on this gas are not functions of the velocities of the molecules, nor, explicitly. of the time.' The author hriiigs his paper to a conclusion without instituting any comparison hetn-een the results of experiment aiid those of his lengthy atid inmlved calculations. UT. L . Ar. ~
On the calculation of the variations of the gases from the laws of Boyle and Charles and on their dissociation. L , Boltzriini~ia. Sif.xu,rrshei.. A k i r d . II'iss. N ' h , 105, I I I A 'I 695 ( 13961. Formulas to replace that of v:m der \Vaals are cieriuced by combining various assumptions as to the forms arid repu1::ing forces of itio!eculei. with a theorem on their (1istril)ution in space : the results agree in part with those of Loreiitz aut1 of Jaeger. The second part of the paper is devoted to a theory of tlissociation, based 011 the following special assumptions. " The atoms are elastic spheres. . . . iminetliatelj- adjoining a small part of the surface of each atom is a sinal1 space. the ' sensitive space'. .. . it is 0111:- when the relative positions of two atoms is such that their sensitive spaces partially coincide. that the two atoms can exert attractive force 011 each other, . . . these attractive forces may he called the The consequences of this theory are developed, with the ' chemical forces '." satisfactory result that froni very sitriple assumptions we h a ~ earrived at the well-known funclaniental eqiiations of the dissociation of gases. There is. naturally. not the slightest difficulty i n treating the more complex cases of (lissociation according to the same principle . . . \Then the sensitive space is distributed uniformly over the whole surface of the atom, the laws of liquefaction of the gases may h e obtained ; since as soon as a noticeahle nuniher o f double atoms exist. numerous aggregates of rnaiij. more atoms \\-ill iiIimediately I I -, L . .IT. be formed. ' ' Contribution t o the theory of gases. G. Jnegei-. Sifzzmgshei.. A k n t f . rl'iss. Tl'ieiz, 105, ( I I A) 79r (1S961 . The paper contains :I . -1 deduction of ~n der JVaals's equation. from the ordinary assurriptions of the kinetic theory. but tjy an improved method. 2 . Determination of n fin van der n'aals's equation) as a function of T. exact representation of f ( T ) is probably impossible ; we \\-ill, however, attempt to render plausihltt a temperature function which is in every respect in agreenient n-itli experiment. '' TYith help of the theory of prohahility, the author succeeds in rendering plausible an expression which agrees i n ever>respect with experiment-even in its application to the dissociation of gases. ' ' ' I
j. .Is the relation lietween the average inner energy of each gas molecule ant1 tlie average energy of progressive motion is inclepeniient of temperature. the quantity of lieat that must be supplied to bring ahout the dissociation of a molecule is proportional to T. From this it follows. tliat, for acliabatic expansion witliont performance of n-ork, the fall in temperature is proportional to the tlifference in pressure. and in\-ersely to the square of the ahsolute temperature - i n agreemelit with Joule's and Thompson's: experiments on air and carlion tliosid. I n the good agreement h e t ~ e e t iexperimental results antl tlie formulas deduced from our tlieory " the author sees * * a certain guarantee of the correctness He would he inucli inore likely to secure tlie reatler's adherence to tlie vievs in question. could lie h i t account for the striking paucity of new results obtained 1 ) ~means of a tlieory so successful at accoiunting for ' ' antl lr'. L . LIZ. renderiiig plausible '' results arrived a t iiiilepeiidentiy of it. "
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The scientific papers bearing on the compression and liquefaction of gases. s I, ,io. 7z, 103, 11897). . 1historical Z ' O I L lt7irktw7*. Zeit. c o i u f l . ~ Y ~ i sGnse, lt'. D. L'. sketch of the subject. very useful for reference.
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On the volatility of compounds containing fluorin. L . H~'aq,. Reczteil Trav. Pays-Bns. 16, zrS ( r S p 7 ) . IZevien-ed [I, 632j from Hull. Acad. roy. Relg. ( 3 ) 33, 1 9 j i 1897). On the chemical decomposition of sulfur. T. Gross. E/ekf~-oc-lie?ia. Zei.il. By fusing together ferrous sulfate and potassium chlorate the author claims to have obtained a substance 6 which has many of tlie properties of silicon ; hut which is said to be a new elernent. For some unexplained reason the author does not see fit to prepare this substance on a large scale. He has not yet decided v-liether this substance 6 is the same as tlie ' ' h-tliiurn " 1V. D . B. previously isolated by him ( I , 620). 4, r z z ( 1 8 9 7 ) .
TILV-COI~ZPOJIF?~~ .Cj~steiris On the solubility of ammonia in water at temperatures below o o C. ]. ?$I. .lZaZ/ef. A m . Cheiii.]oi~i*.19,804 ( ~ 8 9 7 ' 1 ,The solubility curve for aninionia in water at 74.4 mm pressure is curiously wavy, appearing to ha\-e a point of inflection at ahout -1o0 and another at about - ~ 5 ~ This , latter may be due to experimental error since the partial pressure of the ammonia is high at that temperature. u. B.
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The theory of osmotic pressure and the hypothesis of electrolytic dissociation. H. C r o i i i f l i o ~ .] o u r . C/ze/tz. SOC. 71, 925 (1897'1. I t is assumed that van 't H u f f assumed, in working out the relation hetween concentration and change of freezing point, that the solvent had the same reacting weight as liquid a n d as vapor. From this it follows that we must always iiisert a correcting factor for the association of any liquid solvent. The value of this idea \vould be increased if there were an>-g o u n d s for the assumptions. I t is also assumed that solid acetic acid is supposed to lie in equilihriunl with a solution of benzene in acetic acid when the vapor pressure of the solid acetic acid at that temperature is equal to the total pressure of the vapor in equilibrium. -1s might he
espectetl. interesting conclusions riiay he and are (lr'L\\-ii from these preiiiisea. The autlicr also states tlia: pure ice does not separa'e froin it niisture of alcohol anti water. ir-. [I. n. The dissociation of electrolytes as measured by the boiling-point method. niid S. H . A-z'ng. Alii. ClrcilL. J o u r . 19)jj.; 1 i S y i j . ZIeasurements o f the lioiliiip points of solutions of potassium iotlitl ant1 o f s.x:i~urlact.tate in alcohol with the illodifierl Heckmann appsratus I , 743 J . 111 a one percent potassium iotlitl solution the dissociation seem.; to be :iliout ti\-etitJ--+ispercent aiitl the authors call :Ittention to tlie fact t h t the ratio of this ( l i s jciatioii t o the tiissociation iii a corresponding aclueons solution is n1)wit the s inle as tlle ratio of tlie dielectric constants of alcohol aiiil w t t e r . I n ii uiie percelit wlutioii of sotliurn acetate there seems to lie less than two percent tiissociation : l i t i t the authors think that this is slue t J an impurity of potnssiuin acetate. 11.. 21. 0.
H.C.Jorics
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Racemism and pseudoracemism. F. S . A*ip,biiiR niid TI'. J . Pope. j u i i i . . CI2c7tz. Suc. 7 1 , 9 \'9I 1S97 1 , IVheii a dextrorotatory anti a laevorotatory coiiip3un:l conihine t 3 f x n i an iiilictive c s i n p u n d the authors call tlie iiiactil-e sui)stance a racemic corripoui:d if its ' ' crystnllographic propertits differ in a iiiarketl iiiaiiiier from those of its active coriiponents" and a pseutioracernic compound if its * . crystallographic properties resernhle those of its :&\-e constituents so closely as to render tlistinction c1iffic:dt." The racemates \vout:l tlieii lie conipounds while the pseudoraceinates n-auld correspond to isoiriorplious solutions. The distinction seeiris to have merits, hut the authors are not clear as to n-hat they iiieaii 1)y their words and therefore leare the reader in a hopelessly colifused state. If the distiiiction is s3uiicl. a rriisture containing the tlestrorotatory and heyorotatory nicldifications not it1 e q u i d e n t quantities should give two kinds of crystals if a racemate he formed and only one set if a pseutloracemate is possible. This simple esperirneiit was not tried. This is but one of many cases where a kiio\r-ledge of the general principles of chemical equilihriuni n-ould he of advantage to tlie organic chemist. I f ' . u. 11. Solution of liquids and solids in gases. 2'. l'illai-if. S n n c e s .Sui. P/ij,s. Pam's, 1896,233. Revien.eci ( I , 2 j j ; from Jour de Ph)-s. i 3 ) 5 , 153 [ 1Sg6I .
Electro!j'sis aiid Elect 1.0 Zytir Oissociof ioit The influence of temperature on the migration velocity of the ions. A. Atii. A c m d . Sci. Toviizo, 32) 735 1897). IYitli a copper sulfate solution containing 1.93 percent of the 1iydrateJ salt, the transference nurtiber for the anion is 0.636 a t I , j Oand 0.612 at 4 ; ' . IYith a 4.73 percent solution the values are 0.6jS a t 7 ' , 0.651 at 1S3 and 0 . 6 2 s at 4S5. n'itli a zinc sulfate solution containing 3.93 percent of t h e hydrated s d t the corresponding ralues are 0.666 at I j o and 0.674 at 46", while a 7.36 percent solution gave 0.67s both at Ij" and at 4 j o . This last solution was peculiar in that the values calculated from the change of concentration a t t h e anode were ahoxt eight percent smaller than those based on the change of concentration a t the cathode. The author explains this by assuming that the water of crystallization tloes not form part of
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the solvent u n d e r these circiunstances. IVitli :I 3.36 percent solution of lead nitrate the transference nuiri1)er for tlie anion \vas 0.495at S o . 0.jog at Ijo and 0.493 at Jjc..ill these results are ill flxt contradiction with those of Lussana, Atti Istituto Yelieto, 3 , (1692'1. The author gives reasons for his helief that Lussana's riieasurenients are inaccurate. I{'. D . 6.
On the energy of some bases with mixed properties. C . C n w n ~ nn?zd C: /r'eucf. Arm&!. Li7irci. ( 5 'I 6, 152, zoS ( 1697). By bases with mixed properties the authors mean suhstmices like glycocoll conttining an acid aiid a basic group irliicli may each neutralize tlie other. From detenninatioiis of the conductii-it- of the 11)-drach1ori:ls t h e hydrolytic dissociation and therefore the strength of t!ie:ie h s e s caii l x cAculatec1, as has been s1io~1-11 hy IL-alker. The order as fsuiicl is n-clitrieth~-lli~~lros-sulfidopropioiiic acid, clirr~etli~-lliydrosJ-sulfidoacetic acid, dieth!-lli?-tiros)-sLilfi(~oacetic acid. betain and ~-dimetliylhydrosysulfidaacetic acid, the first being a stronger base than urea and tlie last weaker t!isii pyriclin. Substituting selenium for sulfur increases the strength It: D . B. of the base.
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The formation of mercury films by an electrical process. R. A p p l e y n d . Proc. /%j's. Sol. L o u d . 1 5 , 119 (18971. If a sheet of gelatine. damp leather, or similar permeable substance is u s e ~ las a separating diaphragm between two bodies of mercury, and a current is sent tlirougli it, a film of mercury is cleposited upon the surface connected to the positive pole of the battery. The film rernaii:s 011 the diapliragni after the removal from the apparatus. "
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On a peroxynitrate of silver. E . .JIu/der ~ J Z ~Nei*i?zgn. ?J. Reciieil Tmv. P o ~ f s - B n s1,5 , 235 (1S96); 1 6 , 5 7 ( z S 9 7 ) . The hlack compound formed at the anode of a silver voltameter ( I , 323 ) has tlie ernpirical formula j-lg,O.jO.AkgSO,. It contains 110 water and loses five of eii slowly at ordinary temperatures, esplosirely at high temperatures. F r stud>-of the substance while undergoing slow decomposition, tlie authors conclude that tlie formula j.lg,Ol.AgSO, represents the facts better than any other. TV. u. B. The self-recording of electric currents by electrolytical methods. P.Ci+itzElckfr.ochei/z. Zcit. 4, 97 (1697). -1 piece of paper which has beeti dipped iii starch and potassium ioclid solution is passed at a regular rate over tu-o platinurn electrodes. The author discusses at leiigth the drawings obtained liy using alternating or intermittent direct currents. The article contains many illustrations. W. D. B. mi'.
Gold, zinc and electrolysis. E . AiidreoLi. ELektr-ocheiu. &if. 4, 149 ( 1 8 9 7 ) . A description of the different methods of reducing gold froni a cyanic1 solution and a discussioii of the relative merits of tlie electrolytic process and the precipitation with ziiic. W. D.B.
