REVIEWS
Geiit2ml
On the variation of energy in isothermal changes: On electric energy. H . ILllnt. Coiupi'cs veudu:, 125, 699 I A ' Y T ) . -'The heat d Q a n d t h e work dl\- atltled to a system of hotlies in a n y reversible therniodyiia~riic change 1
inay I J representetl ~ as
dQ ---- ndT - bd-??, dW : /dT t+d.z- ; ~vliereT is t h e therniotlynaniic temperature. and -1- is aii a~lditionalraria1)le serving t o define t h e state of t h e system. Coiii1)iiiing these equations \vitli -
~
(1'1-
~~
(2's -
~~
J d Q ~dlY,
dQ T.
for t h e differentials of the energy and t h e entropy : writing the condition that these Ilifferetitials are exact ; and eliniinating ; one finds
h
--z
'r a h j (aT
312 \
ai/*
which is termed ' t h e generalized Clapeyron formula
*.
For ixotlieririal chanyec
o f the energy we h a r e
The quantity of heat liif.1- reqnisite to tiiaiiitaiii the temperature coilstant \rlien .I- c1i:iiiges is often replaced '7y ~- hif.u. \vliicli is an error. BJ- W I J - of illustration. t h e proper calculation o f the isothernial change of energ). is made for t i l e transfer of electricity froin one plate to t h e other of a contleiiser. J . E . 7.
A revision of the atomic weight of nickel, 11. T. Il'. /I'ir/ra?-ds and L-l. S. Prac. A I Z .A m d . 34, j-.ii'y'yy .-'The nickel Ilroinid usetl iii the first research (2, 596) contai-led traces of sodiurti hroniid. The n o r k has h t e n repeated determining hoth t h e nickel and the brornin. T h e most prohal)le value is jS.706, ~i-hichis undoubtedly accurate to within one ttii-thousantith. 1IV. D. 6'. C2rs/ri~[zu.
8,
A revision of the atomic weight of cobalt, 11. T. IY. R i i l t n i d s (2nd G , 1'. Pvoc. '311~.A - l c u ~34, . 3.51 I iSug . - T h e colmlt Ironiitl prerioudy analj-zed (2, 396 I contained traces of other lxomids for lvliich an accurate: correction cannot IIOT\- he given Two new series gave 58.992 an~lj9.004for cuhalt. t'tzstev.
the average being jS.99S. The tn-o previous series gave jS.995 and jS.9S; un. For the present the authors prefer to take the mean of these four .ggj. though they incline t o t h e belief that t h e true value is almost e s actly j9.000. r f r . 11. R. The use of vacuum a s a means of preventing loss of heat. A. rl'eziihozd. Il'icd. ,4i/iz. 66. 5 4 ; (189~c). This is a claim for priority in the use of the vacuum cliatrilier as a means of preveiitiiig lieat loss. The idea is claimed by il'.lrsonval, Init the author points out that he puhlislied an accoiint of the inetliocl s e w n years previous, in TSSI, H. T. B.
A n apparatus called a hermetical pourer. R.Pel-.roirize de Sciziie-joy. Coirzjfes ?-e?zdiis.126,rr+ (iS98~.-- I3j- means of a p~iiiip with a plunger it is possible t o dralv liquid from a herineticai1~-sealed vessel xitliout letting in air. T h e apparatus is recornnieiitietl for use with petroleum and other i~iflatntiialile 11'. 0 .6. or volatile liquids. On a source of error in the Andrews's method of measuring the specific heat of a liquid. E . G?ii?z/ichntid H. F. Il'iehe. ll'icd. Alii/. 66, 530 (f8y3). The method of caloriirietry due to .hidrei\-s is similar to t h e better lino\rn tiietliod of Fa\-re and Sillm-niaiiti. Instead of introducing the liquid untier esperirneiit into the iiiercory hulh as in the latter. the mercury bulb is iiitrotlucetl into the liquid. I n hoth cases the cliange in the volume of iiiercuq for mi observed change in temperature of water gives tlie lieat eqiiivalent of t h e stein. T h e source of error pointed out hy the aiithors is so self-el-itlent that it nould seein alisur(1 t o go into t h e matter at all unless the>- hac1 atteiiiptecl to make a more careful study than they have clone. The error is in t h e assu11111tioii that tlie same qiiantity of lieat \vi11 he giveti 1111 by the hulh to liquitls \vliose eiid temperatures tliffer. The lieat given up, as the authors point out, is not oiily dependent oil the mean difference in temperature hetweeii the h u l h and the liquid. but also on the total contraction of the mercury which is contiitioned hy the volume of the hulh. I n n w k i n g ivitli salt s:ilntioiis at l o w temperatures this error woultl proba111~-amount to coiiqiderahle. The authors entleavor t o tletermine the size of the error. hut their errors of o1)servatioii conipletely lilind a n y conclusions they rnay h a v e ari-ivetl at. T h e correction deduced by the authors amounts to ahout one iii a thousand per degree (lifference iii the end temperature of tlie liquitl. Their errors of oliservation amount to neari!. oiie percent, wliich is not surprising when their total rise of temperature is only r.6S0 and they trJ- to measure this ~vitlia mercury thermometer divitletl to tenths. H. 1: 6.
On a method for the estimation of the thermal conductivity of solid bodies. I?. A ,.Sfhz~/zt*. IYii-tl. Ai~iz.66, 20; ( rS93 I . -The method is very simple althoug-li the aatlior rather hliiids i t with too profuse niathet~iaticaldiscussion. .I metal rut1 coiisiileretl of infinite length conipareti v i t h its diameter is carefull?eticioseti for t h e most part in w d d i i i g in order to keep it duriiig the esperimetit at an equable temperature. . Ita distance of from 1 to 10 em. depeiidiiig 011 the iiatiire of the metal used, froin uiie elid left esposetl. a therniocouple ironcoiistaiit,iii') is placet1 in a small boring. .4t a gireii moment a stream of water
i. a l l o v d to play on the exposed end a t a telriperature different frorii that of tlie protectetl length of t h e rod. T h e change iii the temperature of the thermocouple is iiotetl by ol)serviti:: the cllaiige in the galx-at1onieter readiiig. As the deflections pass through even scale readings the times are recorded 011 a chronoqrapli. Tlie deflections finally show that t h e tetnperature is approaching a steacly state. By taking another series of observations with the stream of water at a different temperature the times are compared for tlie attaiiinien t of the saiiie gal\-anonieter tleflectioii. From these two series of observations the thermal cotiductirity may he deduced hy making the follo\ving uinptiolis : ( 1 \ T h e eiitl face of tlie rod accepts nionientaril;\- t h e temperatare of the streatii of \ v a t u : ( 2 That the galvanometer scale m a y he consiclereil a temperature s c ~ l e of equal parts for the tlierriiocou1)le. Taking 6,. 6., t , atid ti a s the corresponding ternperaturesaiicl times of equal z c d e {leflectioiis. then tlie coefficient of temperature cotiductioii "r may he calculated : for taking 6 as tlie temperature iiitlicaterl by the therniocouple. then 8'
J
.IZKI
1,
where -2- is the distance of the thermocouple froin tlie end of tlie bar uiider the influence of the stream of water. Hence
Tlie author tiiscusses rnatheinatica1l~-the correcti1e.s of the two assuiiiptions :in(l xr-orks out sinall corrections that are necessary to he applietl to the readiiigs. I-Ie also x o r k s out the itifluriice of t h e surrouncling temperature oii his r e w l t > ani1 finds it varies coiisitleralilj- with tlie tiriie. froin about two parts in 1000 for x seconds t o 10 percent for one minute. He closes the paper by giving tlie reh*.iltc of his determiiiatioiis 011 a copper rod i c i ~ dianieter i and jj c m loiig. The \.slues of .I- cle(luce(1agree 10 ahout 3 percent. his iiieaii r.alue being o.6roX gram-calories. N.T. 1;. (2//e-C d ~ i r f lnet/ o 1 Si's1e m s
Measurements of vapor pressure, 11. G , 74?. * Xi i hI Z h ~ ~ t m &it. . ~LJ,.,. -The article presents in condensed forin the results ohtaiiied hy the author and f i \ of ~ his pupils duriiig several years of work. Ti71ei1 a liquid lioils. t h e pressure in the retort is tlie s:inie as t h a t nieasured at the end of tlie condeiiser. Tlie tlytiainical inetliod of deterrriining x-apor- tension^ ih ieverel- tested atid is shown to yield satisfactor? results. The author alii:- (liscusses t h e relative accuracy of vapor-tension rneasuretiients. alii1 defentls liis inetliod of interpolation hy use of curves constructed on a large scale.
The hoiliiig-points of tlie series of fatty acids 1, C, to Clo I 11-ere deterrriirietl a t a large nuniher of pressures varying from I O mi11 to 760 iiini. -1cotnpariwn of the results ohtailled with the 1)uiling-poiiits calculated from those of water and propionic acid by tlie use of Ihiliriiig's Ian- showeti only approximate agreement, t h e differences being greater wlieii the comparison is made with t h e values clecluced from water tliaii \\-lien tliose derived froin propionic ncid are used. Diihring's law is therefore oiily approximate. IYlieti the differences hetweeii the boiling-poiiits of the acitls of this series are cornpareti, it appears that in t h e case of formic aiid acetic acids ant1 also notioic a n d tlecoic acids the differences (lo not vary nit11 the pressure. so that tlie hiliiig-point cur\-es of each of these pairs are parallel. Divergence of the curves of acetic ant1 propionic acids takes place as the pressure tlimirlisties. In d l other cases the curves converge as t h e pressure decreases. The foiloiviiig are the hiling-points of iiiiie heiizeiir derivatives at 760 mtn : henzene Y0.j'. lirotllhetizriie I j j . j c i)enzaltleliytle . r7S,j", plienol I S I . J O , aniliii I S 3 . go, heiizoiiitrile 1 9 0 . 6 benzyl ~~ alcohol 205 .n", tiitro1,eiizeiie 208.3". benzoic acid 249 0'. .It 6 tntn the hilitig-points are : 1)ronioheiizene 32.j'. benza l d e h - d e jj 0'. 1)eiizonitrile 59.9'. aililin 60. j ' . phenol 6j.3' nitrobenzene 7 6 . t 3 , heiizyl alcohol S3.9".beiizoic aciti. 1 2 1 . 2 ^ . Thus intersection of the hoilitig-point curves occur i n t h e iollo~vitigcases : 1 ) e n z o l l i t r i l e - p h e ~ ~hetizoiiitrile~)l. aiiilin, aniliii-phenol. hei~z!.l alcoliol-nitrol,elizene. I'reviously t h e only k n o ~ v i ~ case of iiitersectioii of boiling-point curves \\-as that of ethyl alcohol-henzene. The hoiling-points of aniliii ant1 its methyl, ethyl. clinietllyl and diethyl clerivati\ es u e r e tletermi~ieclat pressure> rangiiig from j t ~ i mto 760 I x l m . T h e 1)oiliiig-point curves of anilin ant1 tiiinetl~ylaiiiliti converge as the pressure tliniinishes, as do also those of inetliJ-l and ethyl atiiliii : but those of methyl and diethyl aiiiliti diverge. 'This niakes the curves for atiiliii antl rnetliyl anilin and again those for ditiiethyl ant1 etIiJ-l atiilin parallel. t pressures raryitig from I IIIIII to 760 m i l Boiling-point determination. of acetophenone. henzoyl cliloritl, alitl triethyl henzoate show that Schroeder's rule t h a t substitutioii of the groups C O . C H , , COUCH,iiietaht:ihle. Ti-lieii tlie lirliiiils are arr;iiigell i i i tlie liriler of their rolu1)ility in ivater. i t appe;irs tliat tliis ortier is tlie b;iiiie a s tlixt i j l i tainetl \vlieii the). are arraiigetl nccortliiig to their Ilielrctric cviiitaiitp. .icetic acid. isol jutyric aciil. isol,ut>-l alcohol a i i t l furfurol are iiotal)le esceptitrii.; to tlie
L . A-.
r11Ie.
Combination of organic bases with different salts of oxygen acids. fl. 7'0)izi-rnticts, 126, 96; zSy,-xvitli falliiig teiiiixriitiire. lxcotiiiiig l)i-iicticall>-%era at ahout q o ' . =\liove j20s there is re\-ersil,le ec~uilihriuin.t h e pci-ceiit:ige ilecoiiiliositioii I J seleiiiuin ~ hyilriil ilecreasing a i the teiiiperatui-e ri.ci to j;O3 mitl i i i creasing List h e teiiiperature I-ises lir!.viitl j;o". The 1 ~ p e also r coiitaiiis a I-erx 26,
~
antl tivo of \\-ater, the one Xvith eight o f water occurring in t\vo rnoclificatioiis. of \rliich one, tlie 6 form, can never exist i n stalile equilihriurn with solutio11 and vapor. The folloir-in# stable quaclruple points were determined : ice antl lIgCl,12H,O a t - ~ ~ - 3 3 . 611gC12r2H,0 '; and 31gC1,SH,0u.at - r6.S0; 31gCliSH,0u ant1 31gC1,6H20 at -3.4' ; 1IgCl26Hy0and lIgC1,4H,O at 116.7' ; 31gC124H.0 It was not possihle to work above 1S6O onin,g to ant1 3IgSl,zH,O at ISIO-ISZ'. the evolution of hydrochloric acid. The hydrate with twelve of water melts a t -~16.4'. The follo\viny labile quadruple poiritswere fount1 : ice and 31gC1,6H80 a t ahout - jo" lij- extrapolation;; JIgC1,12H,O and the hexahydrate a t ~- 19 4 ' : MgC1,1 2H10 ant1 lIgCliSHIO$ at 17.4'; 31gClISHIOB and the hexahydrate at 9.4'. In adtiition there are numerous quantitative determinations of point> on the houiiclary curves. ?K 11. B. ~
~~
Experiments on t h e solubility of the carvoximes. H . Goldsrhuzidt tr~zdH. C. Cooper. Zeit. $/zJ~s.Chem. 28, ? r r ( ic'.9S).- The possihility that dextro and laevo modifications of a n optically active cornpound, which are soluble to the same extent i n inactive solvents. might have different solubilities in opticallp active solvents was suggested by v a n ' t Hoff. .iccordiiigl>- the solubilities of dextro. laevo and inactive Carl-oximes in dextro litnonin were tested. The result \vas that the dextro and laevo niotlificatioiis slioiv no difference in solubility. Liquefied inactive carvoxinie ( i . e . the racemic mixture) was soluhle to the same extent as tlie dextro variety, hut the solid inactive mixture had a solubility different from that of the dextro cornpound. This shon-vs that in the liquid state the inactive compound is only a mechanical mixture of the dextro and laevo varieties. so that the racemic condition really only has significance when the mixture is in the solid form. Rapid crystallization of the inactive compouiitl from solution or from the molten state apparently yields a mixture of crystals of the dextro and laevo varieties which after a time change to the racemic form. L . K. Action of calcium sulfate on some alkaline halids. A. Ditte. Coii~pies potassium chlorid is added continuously to a solution saturated with respect to calcium sulfate, there comes a point a t which the dou1)le sulfate K,SO+CaSO,~H,Ocrystallizes. Some analyses are given of the solutions along the 21' isotherin: hut the nature of the solid phases is ignored. The same phenomena occur when the bromic1 or the iodic1 of potassium is substituted for the chlorid. K i t h ammonium chlorid no douhle sulfate is formed and one is iiot ohtiinetl with sodium chloritl. The author is much handicapped by his ignorance of the phase rule. 1). B . i~e72dus,126,693 (189s).-l\-lien
w.
On t h e causes of the reciprocal displacement of two acids. A. Colsoif. Co7,zpfrs re7zdus, 126,S3r (189s 1 . -From the text it is inipossihle to make out what the author has actually observed. Only this niucli is clear : &It12" hydrogen sulfid is not completely ahsorbed by -4g,PO,, while it is at higher ternperatures. Since the reaction is exotherrnal, this behavior is unintelligihle unless the author has been studying a case of false equilibrium. 1V. D . E . Influence of temperature on chemical reactions. A . Colso~z. C07izptes rendus, 126, 1136 i S 9 S ) . - -11103 hydrogen sulfid does not act perceptibly on dry Zn3iPO,), ; hut decon~positiontakes place at I ~ O .rapidly at 1 6 0 ~ . The :I
mass of hytlrogen sulfid decotnposeii in t h e unit of time is proportiotial to t h e
square of the pressure. E v e n at oo hydrogen sulfid reacts u i t h cupric ortholl'. l7. phospiiate or pyropliosphite. t?iouqli very slowly.
n.
On the formation of the carbids of the alkalies. of the alkaline earths, and of magnesium. H . .I/oi.sstzrr. Coirzpfes r-eizdrts, 126, 302 (18:?, - rtiarketl absorbent properties. 11'. Zl. h'. 126,
i ~ S ~ S -If 'I,
0.iiizot i r Prtssrc re t i r r r i Ili'itsion Effect of the X-rays on the phenomenon of osmose.
H . Z?oi-dier.
Coitipfi2.s
rtvidits, 126,593 1 3 9 , 1~. -"iVlien tlie X-rays passed down through a solution of cane sugar to the nienihraiis, t h e rate a t which water diffused into t h e solution was reduced very decided1:i. T h e same effect n-as produced when a bit clf alut n i i i u t r l foil was placed betmeen the soiirce of the rays and t h e solution. T-nfor-
tuiiately it did not occur to the author to reverse the position of t h e solution a n d tlie xulveiit and see wlic.tlier the rate of diffusion was increasetl. The sug. gestion is macle that tlie action of t h e X-rays upoii living tissue may be colitiected with a rlizturhatice of osmotic equilibrium. 1v. D . R. Osmotic experiments on very dilute solutions of cane sugar. A. pOot/.TU/. Coiirptes ?,ei/dits. 1 2 5 , S67 ( rLq97 --Reviewed I 2, 2 0 3 ) from Bull. Soc. C l ~ i r r ~ . 1.
Paris. 1 3I 19,9 ( 1 8 9 s ) . S t u d y of physical and (chemical e Cornfifes m r d r i s , 126. 335 ( z S 9 stud:- of chemical and physical equi sot.
ilibria by t h e osmotic method. A.Pot,. -.A statement to t h e effect that t h e ria can be simplified by assuitling t h e
csisteiice in the solutioii o f a iiuiiiber of hoxes serriiperiiieaiJle with respect to rlifferent coiiipoiieiits, each 110s heiiig provitletl with its ow1 pistoii.
IC'.
n.1;.
On the diffusion of gases through gelatine containing water. ,-I. H ~ r ~ q ~ ~ u b a d . Wied. Aun. 65, 67-3 1/89 -The tliffusioii of gazes through a solitl solutioii of twenty perceiit gelatine i n xvater i n presence of ail escess of the latter is in\-estigatetl. For a tlescriptioii of tlie apparatus aiid method t h e origiiial article must he coiisultetl. .it 14' to 15' antl with a differelice i i i pressure of oiie atniospliere. the follol\-iiig volumes of gas expresser1 in cubic centinieters at oc and 760 riinl pass through a cube liaviiig a i 1 etlge of one ciii of the gelatine solutio11 in one ( l a y : CO, O . S l j , S ! O o.jo9.H1 o.oj6j, H,S 3.96, 0, 0 . 2 3 0 . S H , 1271. The coefficients of ahsorptioii of these gases in the gelatine solutioii were also determitieti. They were found to differ hLitslightly froni Ruiiseii's results for water, the percentage tlifferencrs are greater at I o n temperatures. Calculation of the diffuiioii constants K l i (livi(liiig ~ the ahove \-olunies by Ilunseii's coefficients of absurptioii of the g a w h hy water gives the follo\\-ing results : CO, at I j3 ~ . S l j ,at os 0.770. S ? O at 14' o 634.€1, at 14' 2.95, H,S at I j.5" 1.24. SH3 a t 17' 1.j94, 0, a t 14' 7.j5. Tlie author apparently incliiies to the l-iew t h a t t h e relativelj. high value for o rei1 is due to chemical action of this gas oil gelatine. He hopes to iiivestigate this further. -1 coniparisoii of these tliffusioii coefficients \villi thase foiuitl by HLLfiier for xvater shows that tlie former are sniriller tlirougliout with the i posiihly only appdreiit) exception of osJ-geii. T h e results obtaiiied iiiclicate that Esiier's law that the voluines of tlie diffusing gases are to each other as their cdefficieiits of ahsorption aiid inversely as t h e square roots of their tleiisities is only approximate. L . K. ~~
lizlorities The rate of hydrolysis of maltose. .-I i ' o n Siymoxd. Z c i f . p h 3 ~ s .C h e i ~ i . 27, 38j ( 1 8 9 8 ) .- Tlie article contaiiis polariinetric measurements of the rate of tlie ahoi-e reaction in tlie presence of hyclrochloric, sulfuric antl oxalic acitls. 1lie reaction is rrioiioinolecular aiitl oheys tlie saiiie teniperature law as ciiiie sugar. The rate is however much less tliaii iii tlie case of the latter suhstaiice. F. 8. h*.
.,
Effect of the concentration on the reaction velocity. A.it. Hciiipfiitiie. C/zei/t. 26, 728 ( t Y 9 S j . -Tile reaction tva? the formation of ioiliii i n acidified solutiolis of potassium iodid. For clilute solutioiis of potassium iodid the reaction is himolecular. IVith double iioriiial solutioiis of sulfuric acid a satisfactory coiistaiit was ohtaiiied. but this was not t h e case with fifty ant1 eight perceiit solutioiis of acetic acid. The action of light increases the reaction velocity and the effect due t o the cliange in t h e strength o f the light is ahout t h e same no matter what the acid. T h e catalytic action of oxalic and acetic acitls is iriucli greater than ~ v o u l dbe expected froni t h e conductivity. IVith iticreasi n g concentration of acetic acid tlie reaction velocity increases u p to a niaxiinuni for seventy percent acetic acid. The action of concentrated acitls 011 metals is also very different from tlie action of dilute acids. This paper is merely a preliniinary study. 167. n.B.
Zeit. plzjs.
Catalytic action on the speed of oxidation of sodium sulfite by the oxygen of the air. S. L. Bigi.io;i,. Z ~ i t )Jij,s . C / i e i i / , 26, 49.3 i\iSp through ail aqueous solutioii of so liuni sulfite. the strength mitieti froiii time to time n-ith a staii~lartlsolution of iodin with the aid of :I solution of stxliuti~thiosulfate. The effect of the addition of various substanceschiefly organic- in small an-.outiti 011 the rate of osiciation is tested. \Yith the exception of succiiiic acid. carl>onic dioxiti and ozoiie - \vIiich accelerate the speed of the reactioii - the suhstances tested either retarded the reactioii or had 110 effect. The latter suhstar ces are ethyl acetate. acetone ant1 sotliurri sulfate. The substances that had a rettar~li~ig influelice include prirnary and secontlary alcohols. p l y a t o m i c alcohols phenol. the three cresols, anilin, ether. acetic- and l~enzal~leliycles, heiizene. turpentines. sorlium Iiyclroxitl. potassium tartrate a n d aotliuin succinate. 1\Iany tlifficaltits hat1 to he ox-erconie in order to ol~tuin reliahle result; : and yet after all different samples of water from the s ~ t i i e source aln-ays yielded very iliffereiit results, a fact for i\-liicli no esplanatioti is foullcl. The retardation of the speetl of oxidation of sodium sulfite 111- the substances namecl tlie author ternis catalytic action. The only reason that lie gives for tloing so is that cotisiileralile retardation is caused by sniall amounts of sithstatice. In 110 case does lie shoit- that the substance that causes such retardatioti remains unchanged o--that being difficult to do- that a little of i t \\-ill suffice to retard the reactioii for a considerable period of time, the experiments k i n g run generally only for thirty minutes. S o w the sulistances that retard the oxidation are. with the exception of sodiuni liydrosid. reducing agents ; and indeed the order in which the author arranges the substances as to their retarding influence is, very nearly at least, that of their reducing poxer. The substances that did not retard are not reclucing agents or hut verj poor ones. In the face of these facts it Tvoultl a t least appear doubtful as to whether the retardation of the oxidation by these various ingredients is really ratalytic action. I>.A -
On the catalytic action of platinum black.
zg. i'on
Ht~7/rptin71p.
%i.ii.
t S 9 S 1. -- I11 the hope of throwiug more light 011 the cluestion its to whether the occlusion of hydrogen 11)- platinum black is due to chemical cori~hinatioiior to surface condensation, the author makes coniparati\-e rtieasurements of the ahsorption at ordinary and at very lcnv temperatures. Chetnical comhinatiori \vould probalily he checked by great cold : condensation 011 the other hand would be increased. As a matter of fact cliarcoal \\-as found to condense about six time.; as riiuch hydrogen at -7s' as a t I j o ,while in tlie case of platinum black the ahsorption \vas niuch less a t the lozit temperature. The author, therefore. rejects the assumption of simple surface condensation as the cause of the ahsorption of hydrogen b - platinum black. H e obtains several curious results with hydrogen and carbon nionoxid in palladium. but refrains from drawing conclusions until more detailed esperirnetits shall have heen carried out in boiling air. F. 13.h7. $ / Z J YC/Leii/. 2 7 , 429
I
Note on the rate of dehydration of crystallized salts. T. TV. Richni-ds. 17, 165 (13'98).-Revie\ved ( 2 , 403) from Proc. Am. .icad. 33, 2 3 (1S97).
Zeif.nnurg. Cheitt.
On the dispersion of electrically glowing platinum and palladium wire. TI'. .'5'?ca~rri,f. W i d . A1272. 66, SS i 18937).- T h e author invrstiyates the plienoinelion first pointed out hy Sahrwold that platiiiuni heated to a recl heat by an electric current apparently setids off fine particles. H e also unclertakes a stutlJof palladiuni v i r e as well as platinuin in air, hydrogen. nitrogen, and i n oxygen of different pressures. His method is to suspentl a \$-ire of about 0.2 j nirn tliaineter ant1 r;o niin long hetween two large platinum hooks soldered to copper leads. By enclosiiig the wire in a suitable vessel he is able to introduce the different gases ant1 to maintain them at tliffereiit pressures. The temperature of the wire is kept constant at an\- desired point for all the experiments by nleasnring the differences o f potential between the copper leads and a suitahle rnanganin resistance. The weight of the wire before and after the esperiment gives the amount of tlie dispersion. The results of the work are : T. The strength of the dispersion decreases for hoth Pt and Ptl the longer the wire is kept glon-ing. The weight lost varied from 0.6s percent to o. I I percent after the sixth experiment. 2 . T h e dispersion is the same for dry air as for moist air. 3. The dispersion is unchanged if the wire is surrountleil 1)y a ln-ass tube connected to earth. 4. Tvith decreasing air pressure the dispersion of the Pt tlecreasetl while that of the Pd increased. j . In hydrogen there was no dispersion of the I't ex-en at a clear white heat. The Pd shows only about one-sixth the effect producetl h>-air. 6 . I11 nitrogen the metals s h o only ~ a very weak dispersion. ;. That the dispersion in air is conditioned hj- the presence of osygen.
H . T. 6. E l e c t r o m o t i z Forces On galvanic polarization. H. J n h n . Zeit. p/zj,s. Che?/z. 26, 35" (rS9,?).The author has deterniineil arid tabulated the polarization at oo anti at 40' ; the temperature coefficient of the polarization ; the loss of heat in the hatter! d u r ing the tlecot~ipositioiiof one reacting weight of the salt at zoo ; the heat effects at zoo in the deconiposition cell at the anode and the cathotle for the sulfates of copper, zinc and cadxniuni and for the nitrates of copper, lead and silver. The hatter? used was the niotlifieil De la Rue cell i z , 2 O j I and the measurements were made Tyith the ice calorimeter. Therniodynarnic formulas are deduced for tlie polarization xitli salts of the hea metals ancl xvith acids. The value of these formulas is open to question. r instance, the conclusioii is reached that with an oxygen acid the polarization is independent of the Concentration and ; the extent that the electromotive dissociation of the acid. This is true o n l ~to force of the hydrogen-oxygen gas ce!l is independent of the concentration ancl dissociation of the acicl. This is very nearly the case, so nearly as not to he detected readily in polarization experiments ; but that is not a justification for the formula being wrong. Some experiments were also macle with dilute solu It.: D . E. tions of the salts of the alkali metals.
z,w 12,
On the thermal mercury ammeter. C. Cn?lrie/~e/.C o ? ~ p f e remf?fs, s 126, I> r89Sj. - Soine inodifications in the instrutrient previously descrilietl lb'. B. 7; I.
u.
On the mercury thermal ammeter, its industrial applications ; a new standard of electromotive force. C. CoiiiichcZ. Cori1ptc.8 ?,eirdzfs. 126, ro2S (zL+'9 further discussion of t h e accuracy of t h e new form of mercury aninie preceding re\-ie\v'i. It is poi-itecl out t h a t hy iiitroclucing suitable resistances TV. 11. H . the instrurnent can he used t o measure potential differences;.
Elect roij,.ris n 71 d Elcrtroiyf ic Uissocia i io I I Preparation of glucinum by electrolysis.
P.Lehenu. Com,bfi,s rendirs.
126,744 , tSy,?). - Glucinuni can 1)e precipitated electrolytically from the fusetl tlouhle fluoriil (;E',SaI:. The current \viis 6- j amperes and t h e potential differ1V. D . 15'. elice 3 j-40 volts.
On the alleged decomposition of sulfur.
H . Afe.rn?zdcr-. %?it. Elekiizi-
~ h e i i i i 5~, ,93 ( r S 9 S ) . -The :iuthor has repeated t h e experinleiits of Grosi I I , 620 : 2, 140 : 3, 64). 011 the action of t h e current on inolteii sil,;er chloritl aiitl
sulfid.
So
liythiuni " was obtaineil.
IV. n.c.
The velocities of electrical ions a t 18' in dilute aqueous solutions up t o tenthnormal concentrations. F. J;o/iZ/ ilctsrh. lr'ied. A1212. 66, 7Sj (z.798). - One object of this paper is to test the a ptioii that t h e migration velocity of ail ion i~iiiybe treated as a function o concetitration. disregarding t h e dissociation conipletel-. .Lccording t o this hypothesis t h e migration \-elocitJ-of a given ion at a given concentration \rill always be tlie same no matter what tlie other ion may be. On stuclyiiig tlie apparent change of migration velocity n-it11 the concentration it was found tliat t h e same formula could he used for all iiiiivariant ions \vith tlie esceptioii of hydrogen ant1 hydroxyl. This forniula 1na)- he ~ v r i t t e n/; = I, ~- Qq:. where I is t h e niigratioii \-elocity. qi t h e linear coiiceiitration. and 0 a constant. If the conductivities are expressed in reciprocal ohms t h e value of Q is 2 1 - j . For hydrogen aiid hytlrosq-1 as ion dout1le to tretile tlie normal value must be assignetl t o 0 . I n conipounils coiitaining t\vo univalent and one bivalent imi, t h e change of the migration velocity of tlie liivaltnt ion with tlie concentratioii can be represented approximately hy tlir formula for hydrogen or hydroxyl as ion. 1V:heti 110th cation a n d anion are bivaleiit tlie decrease of tlie inigration of tlie velocity with increasing concentratioii is niucli greater than in .:lie case of t\\-o univaleiit ions. h".
w.n.
On the electric conductivity of solutions of potassium permanganate. E . Lcy i , c z ~ t i . ComPtcs r e t ~ t f f a s126, . 2 0 2 j (1898).- Coiicluctivity tleter~ninationsat 2 j 0 , jj3atid J j " . The temperature coefficient for 12 16 solutions is o.021 Iiet\rteii 2 j 3 and jj3,while it is only 0.014 between 35' and Jj'. The author considerh tliat his measureriients zt high dilutions confirm t h e hypothesis of Bout>- that tlie equivalent c o n d u c t i \ - i t ~clf all neutral salts is t h e same at infinite dilution.
IV.D . B. On the electrical resistance of crystallized silicon. F . LeRoy. C O W I ~ ~ C S reirdr~s,126,z + (~r S 9 S ) . - The conductivity of crystallized silicon varies veri-
much with the degree of pulverizatioii, of compression, etc In round nunihers the resistance is thirteen huntlretl times that of carbon antl the author hopes that sonie day it may lie used for high resistances. IE' 13. R.
On the influence of pressure on the electrical conductivity of solutions. A . Bogojaaslmsky ann' G. T a ~ ~ t i i i t r i i ?Z~ci . t.f i l ~ j , . ~ C7ic;n. . 27, f j 7 (1~\'9
n
Contribution t o the study of electric furnaces. Gifz niid Lc/crt.?-. CO/llflh~-~ 7,e?idrrs. 126,236 (1,q9 -Treating the arc a s a resistance [ See 3, 1 2 4 the a11thors tlecluce the colic ion that if the arc were enclosed inside an aclialiatic surface. the temperature of the arc woultl increase as the square of the current cleiisity and as the ratio of tl-.e resist:mce of tlie atmosphere roiintl the arc to the specific lieat of the enclosiiiq atmosphere. I n niaking calciilrn carhid a 1iriLliant layer of graphite is noticecl nearest the arc and farther off a layer of crystallized calciiirn carhill. T1i.s layer of graphite is attrilmteil hy the authors to the tiissociation of calciurii carhitl at temperatures beloiv tlie siibliniatio~ipoillt of carbon. 14.. 11. 6.
Dielccti-icifj,nizrf Optics a
On the mutual action of two current circuits and t h e application to t h e determination of dielectric constants. ]. A4. 6'rskiizf'. W i d . .4//ii. 66, 269 -The author brings fonvanl a new tnethotl for the tleterniinntioii of dielectric constants, \rhicli clepeiitls 011 the ntt:iiiinient of complete resonance het\vern tn-o circuits. The current induced i n the secondar?-circuit liy a conclenwi discharge in the priniary clepentls elltirely on the capacity ;inil re+miice u i the seconclary circuit. Hence. as the author s h o i v s m~~tl~eiiiatically, I)! rxikiiig the coefficient of mutual ill luction sinall in compariioii with the coefficients of self induction, a large cliaiige in tlie secontlary current takes place it-itli a fairly sinal1 change it1 the capacity. Taking a conveiiieiit capacity for the primary anti iiitrorluciiig ii I
