J O U R N A LOFTHE CHEMICAL SOCIETY,ABSTRACTS OF CHEMICAL PAPERS PUBLISHED INBRITISH AND FOREIGN JOURNALS.General a n d P h y s i c a l Chemistry.Infra-red Radiation Spectra. By H. BECQUEREL (Compt. rend.,97, 71-74. Compare also Abstr., 1883, 761).-The author hasexamined the infra-red radiation spectra of several metals by themethod previously described (Compt. rend., 96, 121).Sodium gives two strong lines of wave-lengths 18190 and 10980,coincident with two lines in the solar spectrum. The line at 8190can be seen with an ordinary spectroscope, and coincides withBrewster’s solar line Y.Magnesium gives three strong lines at 8755, 10300, and 11300respectively, coincident with three lines in the solar spectrum.Calcium in the electric arc gives a strong band of mean wave-length about 8480, coincident with a group of lines in the solarspectrum.Potassium gives five strong lines at 7700, 10030, 10730, 11250 and11820 respectively.Silver gives two very strong lines at 7720 and 8290 respectively.Thalli.1m gives a very strong line at 11050, very near the secondsodium line, but much stronger than, and quite distinct from, thelatter.The infra-red region of the spectrum down to about wave-length8600 can be seen with an ordinary spectroscope by concentrating thelight on the slit and filtering out the more luminous rays by means ofa solution of iodine in carbon bisulphide.C. H. B.Copper Oxide Battery. B,y F. DE LALANDE and G. CHAPERON(Compt. rend., 9 7, 164-166) .-The elements of the battery are zinc,cupric oxide, and potassium hydroxide.The cupric oxide is in con-tact with a plate of iron or brass which forms the positive pole, orVOL. XLVI. 2 ABSTRACTS OF CHEMICAL PAPERS.the outer vessel of the battery is constructed of one of these metals.The cupric oxide is the depolarising element of the battery, and isreduced to metallic copper, its conductivity increasing therefore as thebattery is used. The electromotive force of this cell is about one volt,and its internal resistance is very low and does not sensibly alterwhile the batr;ery is in action. Small sizes give a current of twoamphres ; large sizes give as much as 30 amphres. Since the potashsolution has no action on the oxide of copper nor on the amalga-mated zinc, there is no waste when the battery is not in action.Thereduced copper can be reconverted into oxide by roasting. Thisbattery can be used for long periods through low resistances, sincedepolarisation is rapid and complete. C. H. B.Currents Produced by Immersion and Emersion, and by theMovement of a Metal in a Liquid. By KROUCHKOLL (Compt. rend.,97, 161--163).-1t has been known for some time that if two elec-trodes of the same metal are immersed in a liquid and one of them ismoved, the motion produces a current the direction of which dependson the nature of the metal and liquid. If, too, one of the electrodesis placed in the liquid and the other is immersed afterwards, a, currentis produeed a t the moment of immersion.The author finds that a current is also produced when one of theelectrodes is withdrawn from the liquid.The current a t immersionis in the opposite direction to that produced by movement of theelectrode in the liquid ; the current of emersion is in the same direc-tion as the current produced by movement. These immersion andemersion currents are produced when the metal is passed from aninsulating to a conducting liquid, as well as when the metal passesfrom the air into a liquid. The electromotive force produced bymotion is analogous to that produced by polarisation: i t is destroyedby solutions of salts of the metal of which the electrodes are com-posed, so that if the saline solutions are sufficiently strong, no currentis produced by moving the elecirode. These phenomena can beexplained by Helmholtz’s hypothesis of double layers of electricaltension.C. H. B.Determination of the Limits of Electrolysis. By C. TRUCHOT(Compt. rend., 97, 92--93).-Since the electromotive force requiredto decompose a given compound depends on the heat of formation ofthe compound, it follows that a determination of the minimum elec-tromotive force necessary to produce decomposition, furnishes ameasure of the heat of formation of the particular compound. Theauthor employs a small Grarnme dynamo, with a Jamin magnet, drivenby a Smidt’s water-motor fitted with a special regulating apparatus.The electromotive force is practically proportional to the velocity ofthe rotation of the dynamo, and this velocity can be regulated withinvery narrow limits.The actual electromotive force is determined bya volt-meter graduated by means of a Daniel1 element. Determina-tions of the minimum electromotive force required to electrolysewater, potassium sulphate, and other compounds, agree very closelywith thermochemical determinations. C. H. BGENERAL AND PHYSICAL CHEMISTRY. 3Pyro-electricity of Blende, Sodium Chlorate, and Boracite.By C. FRIEDEL and J. CURIE (Compt. rend., 97, 61--66).-Crystslsof the cubical system which show tetrahedral heinihedrism behavelike crystals of the hexagonal system. If heated or cooled regularly,i.e., so that the expansion or contraction is equal along all the axes ofhemimorphism, there is no development of pyroelectricity, b u t if theheating or cooling is irregular, so that tension is produced in differentparts of the crystal, then eIectricity is developed. These phenomenahave been observed with blende and with sodium chlorate.Mallardhas shown that boracite a t ordinary temperatures belongs to therhombic system, but at about 265" its form changes to one belongingto the cubical system. The authors find that if a plate of boracitecut parallel with one of the tetrahedral faces is heated at 300-320"for some time and then allowed to cool regularly, no electricity canbe detected until the temperature falls t o about 265", but at this pointthere is a considerable development of electricity, which graduallydiminishes in intensity and eventually changes in sign. I t appearstherefore that when boracite cools regularly it only becomes pyro-electric at the point a t which it ceases to belong to the mbicalsystem. C.H. B.Melting Points of Salts. By E. MAUMENO (Compt. rend., 97, 4548).-Pure potassium nitrate melts at 327" ; pure sodium nitrate at298". The following table gives the melting points of various mix-tures of these and other nitrates as calculated and as observed :-3KN03 + NaNO,'2KNO, +NaNO,RNO, + NaNO,KNO3 + 2NaN0,KNO, + SNaNO,KNOs + AgxO3NaN03 +AgN032NaN03 +AgxO,NaNO, + Ca(N03)zl.68KN03 + AgNO,AgNO,+KNO,+NaNO,Calculated. Observed. Difference.320.7 265-247" -55.7- 73.7"318.4 265-244 -55.7- 74.4313.8 265-219 --55*7- 94.8308.8 242-224 -66.8- 84.8306.2 267-2:37 -39.2- 69.2246.8 169-121 - 77'8-125.8262.5 191-131 - 71-5-131.5231.7 251.5" + l!i%"248.0 263.0 + 1s"258.5 190-130 - 68-128.5374 or 399"* 235-216' -158 or 18PThe first of the observed temperatures is the point at which crystalsbegin to form in the fused mixture, and the second is the point a twhich the whole mass becomes solid.The fall of temperature betweenthese two points is perfectly gradual, and there is no fixed inter-mediate point which can be regarded as Ihe true melting point of themixture. The mixtures of sodium and silver nitrates do not showthis irregularity, but have a definite melting point. Calcium nitrate,which cannot be fused alone without decomposition, melts readilywhen added in small quantities to fused sodium nitrate, and does notdecompose. Zinc nitrate behaves in a peculiar manner.When a pre-viously fused and resolidified mixture of sodium and calcium nitrates* According as the melting point of calcium nitrate is taken as 450" or 500".b 4 ABSTRACTS OF CHEMICAL PAPERS.in equivalent proportions is added gradually to gently heated zincnitrate, the fragments of the mixture decompose a t a temperature aslow as 210", and decomposition continues so long as any of the frag-ments remain undissolved, but ceases when the whole mass becomescompletely liquid. The same phenomenon is observed on each succes-sive addition of the mixture. A mixture of the three nitrates inequivalent proportions solidifies a t 170°, about 80.5" above the calcu-lated melting point.Barium Alcoholate. By DE FORCRAND (Compt.rend., 97,170-172). -Barium alcoholate is so readily decomposed by atmosphericmoisture, that it is almost impossible to obtain it free from hydroxide,and in thermochemical determinations it is necessary to make a cor-rection for this impurity. The heat of solution of the alcoholate at20" is + 19.76 cal., from which it follows that-2CaH60 liquid + RaO solid = (C,H,O),Ba solid + H,O solid2C,H60 liquid + BaH,O, solid = (C2H,0),Ba solid + 2H20 solidThis development of heat is somewhat smaller than that producedby the hydration of barium oxide. The reverse reaction (C2H,0)2Basolid + 2H20 liquid = 2CQH6O liquid + BaH,O, solid, develops + 4-56 cal. These results explain the known properties of the alcoho-late. In presence of excess of alcohoI i t is necessary to take intoaccount the heat of solution of the alcoholate in alcohol and the for-mation of secondary alcoholates similar to those of sodium.The heatof solution in a large excess of alcohol is + 20 cal.; if a saturatedsolution is formed it is + 12.50 cal. By reason of the dissociation ofthe secondary alcoholates, an alcoholic solution of barium alcoholatealways contains (C2H50)2Ba. If such a solution is mixed with a smallquantity of water, part of the alcoholate is converted into hydroxide,and the latter, being insoluble, is precipitated. The equilibrium of thesystem is thus disturbed, and the conversion of the alcoholate intohydroxide continues until all the water has been precipitated as bariumhydroxide.The folloiving table shows the relative stability of the metallicderivatives of certain alcohols and acids with respect to water andacids.It is, howe-rer, also necessary to take int'o account the forma-tion of secondary compounds (hydroxides, secondary alcoholates, basicsalts, &c.), since t,he heat of formation of these bodies may change thedirection of the reaction :-2C2H60 liquid + BaO solid = (C2H50),Ba solid + H,O solid2C2H,0 liquid + BaH,02 solid = (C2H50)2Ba solid + 2H,O solidBC,H,O liquid + Na,O solid = 2C,H5Na0 solid + H,O solidC2H,0 liquid + NaHO solid = C2H5Na0 solid + H,O solidC. H. B.develops + 14.48 cal.develops - 1-68 cal.develops + 14.48 cal.develops - 1.68 cal.develops + 34.70 cal.develops + 0.25 cal.GENERAL AND PHYSICAL CHEMISTRY. 52C2H,Na0, solid + NhO solid = 2CzHoNh03 solid + HzO solidC2H,Na03 solid + NaHO solid = CzH,N~OA solid + HzO solid2C6H60 solid + K,O solid = 2C6HaK0 solid + HzO solidC6H6O solid + KHO solid = C,H,KO solid + H20 solidH2S04 solid + NazO Bolid = NazS04 solid + HzO solidH,SO, solid +- 2NaHO solid = NhSO, solid + 2H20 soliddevelops + 34..54 cal.develops + 0.12 cal.develops + 76.4 cal.develops + 17.7 cal.develops + 103.6 cal.develops + 63.4 cal.{{ C.H. 33.Heat of Formation of Potassium Fluorides. By GUXTZ ( C ~ z p t ,rend., 97, 256--258).--Anhydrous Potassium Fluoride.-The neutral-isation of 1 mol. hydrofluoric acid (dilute) by potassium hyd~oxide(dilute) develops + 16.12 cal. The heat of solution of the aiihy-drous fluoride is 3.6 cal. These results agree with those of Thomsenand Favrt: respectively.KHO solid + HF liquid = KF rolid + H,O solid develops + 30-98 cal.KHO solid + HF gas = KF solid + H20 solid develops + 38.22 cal.Crystallised Potassium Fluoride, KF.2X20.-Heat of solution - 1-03cal.: heat of hydration, KF solid + 2H,O, liquid = KJ?,'LHzO solid,develops + 4 6 3 cal.; with 2H20 solid, + 1.8 cal.KHO solid + HF liquid + HzO solid = KF,2Hz0 solid develops + 34.17 cal.KHO solid + HF gaseous + H,O solid = KF,2H,O solid develops + 41.41 cal.The action of 1 mul. hydrofluoric acid on 1 mol. potassium fluoridein dilute solution is accompanied by an absorption of heat - 0.57cal. ; a phenomenon similar to that observed in the case of hydrogenpotassium sulphate.The heat of solution of potassium hydrogenfluoride, KF,HF is - 6.01 cal.KE' solid + HF gas = KF,HF solid develops + 21.04 cal.KHO solid + 2BF gas = KF,HB' solid + HzO solid developsKHO solid + 2HF liquid = KF,HF solid + HzO solid developsKF solid + HP liquid = HF,HF ,, ,, + 13-80 ),+ 53-13 cal.+ 38.65 cal.Compressibility and Liquefaction of Gases. By J. JAMIN(Compt. rend., 97,10-16; see also Abstr., 1883,898).-The author hasrepresented the results of Andrews' experiments by a series of curves,the ordinates of which represent the density of the gas, and theabscissae tlie pressure for the several temperatures 13-1", 2 1 . 5 O , 31.1",C. H. B6 ABSTRACTS OF CHEMICAL PAPERS.32.5", 35*5", a t which the experiments were made. Below the criticalpoint, the curve is a t first slightly convex with respect to the axis a,because the density increases more quickly than the pressure, but a t acertain point, B, the curve suddenly changes in direction.At thispoint, the gas has attained its maximum tension, and liquefactioncommences, the curve continuing in the new direction until liquefac-tion is complete, when it suddenly takes a direction correspondingwith a slow increase in density, this part of the curve being slightlyconcave because the compressibility gradually decreases. That thisinterpretation of the curve is correct is proved by the fact that themaximurn tensions of the gas a t the different temperatures correspondwith the points B, B', B", &c., at which the direction of the curvechanges.Comparison of the different curves shows that the minimumdensity of the liquid at the moment of its formation is a t first muchhigher than the maximum density of the gas when it begins toliquefy, but the difference between these two densities diminishes ast2he temperature rises, and at 35" the difference is nil, from which itfollows that below 35" the liquid ought t o form and separate from thegas by reason of its higher density, but above 35", although the liquidis ail1 formed, it cannot separate from the gas.. The author has calcu-lated the ratios between the density of the gas and the density of theliquid in Andrews' experiments, and also the coetficient of expansionbetween 31.1" and 35.5". These coefficients are very high, and undergoremarkable changes. Between 75.6 and 76 atmos.the coefficient ofexpansion rises suddenly from 0.0821 to 0.2716, which can only beexplained by supposing that at this pressure and at 31.1" tbe gas isreally liquefied, although apparently gaseous, and when the tempera-ture rises to 35.5" it again passes into the gaseous state. Again,between 82 and 83.4 atmos. the coefficient suddenly falls from 0.13114to 0.0703, a fact which can only be explained by supposing that a tthis pressure and even a t the higher temperature the gas is againliquefied, although apparently remaining gaseous. It would appearthat the homogeneous mass in the vessel under these conditions is notreally gaseous, because it has too high a density, nor yet really liquid,because it, has a high coefficient of expansion and compressibility, butthat it exists in an intermediate state. Detailed examination of thecurves corresponding with temperatures above the critical point sup-ports these views.The following table gives the successive incre-ments of density due to successive equal increments of pressure :-Atmos. 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100D'-D - 10 11 12 13 31 38 72 27 15 13 9 8 7 7 5It is evident that between 82 and 84 atmos. the gas is liquefied, andit is also evident that this change although very rapid is not abrupt.It becomes less rapid and takes place a t higher pressures as the tem-peritture rises. The results of Cailletet and Amagat's experimentswith oxygen, hydrogen, and similar gases at high pressures are repre-sented by curves similar t o those representing Andrews' experimentsabove the critical point.In every case the curve is convex at lowpressures and concave a t high pressures, with an intermediate pointof inflexion which, according to the author's view, is the point aGENERAL AND PHYSICAL CHEMISTRY. 7which the gas liquefies.experiments with oxygen at 0.3’ are given in the following table :-The increments of density in Amagat’sAtmos. 20 30 40 50 60 70 80 90 100 110 120 130D’-D - 76 77 77 78 78 79 79 82 83 77 78Atmos. 140 150 160 170 180 190D’-D 78 78 77 76 ‘75 75It would appear that the oxygen really liquefies between 100 and110 atmos., although the change is not so well marked as in the caseof carbonic anhydride.The following table gives the points of in-flexion and maximum compressibility (H) as determined by Amagat’sexperiments :-Point of inflexion. H.Oxygen ........ 102 atmos. 130 atmos.Methane ........ 95 ,, 127 ,?Ethylene.. ...... 67 ,, 83 7,Nitrogen ........ 55 ,, 109 97Hydrogen 0 ,, 0 Y , ......I t is evident that at a higher temperatme these points of inflexionand maximum compressibility will correspond with higher pressures,but at a sufficiently low temperature the point H will differ but littlefrom the point of origin of the curve, and experiments will give onlythat portion of the curve / beyond K, which always represents adiminishing compressibility ; but this is actually observed in thecase of hydrogen.It follows therefore that at the ordinary tempera-ture, and under a pressure of 3-4 atrnos., hydrogen has passed itspoint of inflexion, or, in other words, is really liquid. This conclusionis in accord with the law of continuity, and brings hydrogen, whichhas hitherto been regarded as an exception, under the general laws ofthe compressibility of gases.Change of Volume of Metals and Alloys at Melting. ByE. WIEDEMANN (Ann. Phys. Clzem. [2], 20,228-243).-The author hasmade a series of experiments on ihe expansion of volume at meltingpoint, and the relative rates of cooling of tin and certain alloys ofbismuth and lead.The dilntometer method was employed. The substance t o beexamined was enclosed in a closely fitting glass cylinder, at theupper end of which was fixed a capillary tube.The most con-venient liquid for filling the apparatus was found to be oil, whichhas the advantage of not evolving air when heated to 200”; more-over, it does not possess an appreciable vapour-tension at that tem-perature. When heated above that point the oil attacks the metal.The rate of cooling was determined by heating the metal to 260” in aniron vessel. A thermometer protected by a glass cap filled with oilwas enclosed within the molten mass. The whole apparatus was thenimmersed in a double walled metallic vessel, the intermediate spacebetween the walls being filled with water. The intervals of time re-quired for cooling 5” were carefully measured ; the reciprocal valueC. H. B8 ABSTRACTS OF CHEMICAL PAPERS.for these times may be taken as a measure for the velocity of coolingof the metal.In three experiments, it was found that tin on melting expanded involume 1.76, 1.69, 2.20 per cent.These results are in direct contra-diction to those of Nies and Winkelmann, who melted a largequantity of the metals and then dropped i n a solid fragment of thesame metal, and observed whet,her this fragment floated or sunk. Butthe author points out that in this method it would be exceedinglydifficult t o avoid convection currents, which would be liable t o carryup the solid fragments to +he surface in the centre of the vessel.Experiments also proved that soft solder expands almost 2 per cent.of its volume in melting.Alloys of Bismuth and Lead.-Pb2Bi of sp.gr. 11.4 begins to showan increase of expansion at about 120-136', which reaches its maxi-mum at 180". When heated to 240" and allowed t o cuol, the tempera-ture remained constant for long intervals of time at 180" and 125",the two melting points of the alloy. BiPb, sp. gr. 11.03, expandsabnormally between 127" and 132", melts at 146" and 125". PbBi,,sp. gr. 10.96, expands abnormally between 126" and 132", melts at140" and 124". PbBil, sp. gr. 9-73, expands most markedly between120" and 136", melts at 125" and 200". PbBi,, sp. gr. 8.6, melts par-tially between 125" and 130", contracts between 172" and 204"; itsmelting points are 170" and 120". The results of these experimentsshow that these allojs contain a definite compound of compositionbetween PbBi and PbBi2, whose melting point is about 125", and inwhich the excess of one metal, lead or bismuth, as the case may be,dissolves.For equal increments of temperature, the proportion of themetal dissolved rapidly increases. From the changes of volume attemperatures above the first melting point one can conclude whetherthe metal in excess expands or contracts on melting. The experi-ments would seem to indicate an expansion of lead and a contractionof bismuth, a result in accordance with previous observations. Forexample, the alloy PbBi, consists of an alloy of low melting point, inwhich the excess of bismuth dissolves ; if it be gradually warmed to120", the alloy and the excess of bismuth expand regularly. At thistemperature the alloy melts with marked expansion, and contains thesolid bismuth in suspension ; above that point, the bismuth graduallydissolves and melts, while the rate of expansion pari passzc decreases.V.H. V.Specific Volume of Saturated and Unsaturated Alkyl Salts.By b'. WEGER (Annulen, 221, 61--107).-The author has made aseries of determinations of saturated and unsaturated hydrocarbonsand alkyl salts, in order to ascertain the differences of specificvolume corresponding to known differences of molecular weight.The method adopted is that proposed by Kopp, with slight modifi-cations; the dilatometer was not heated in a bath of liquid, butwas wholly immersed in the vapour of some volatile liquid. By thismeans corrections for the cool part of the dilatometer projectingoutside the liquid, and its unequal heating from convection currenh,are avoided. The readings were made with the naked eye, and TABLE I.Name of Substance. Method of Preparation.Ethylbenzene, CaHIo............................Phenylethylene, C8H, ..........................Phenylacet,ylene, CaH6 .........................Phenyl bromide, C,H,Br ........................Acetylene dibroniide, C2H2Br2 ...................Methyl cimamate, C10Hlo02. ....................Ethyl cinnamate, CllHl20,.. ....................Propyl cinnamate, Cl2Hl402.. ...................Phenylpropionic acid, CgH,,O, ..................Methyl phenylpropionnte, CloHl~02 ..............Ethyl phenylpropionat,e, Cl1HI4O2 ...............Cinnamic acid, CgHaO,..........................Propyl phenplpropionate, CI2lj 1602 ...............Methyl acrylate, C,H,O, ........................Ethyl acrylate, C5H,02 .........................Prop71 acrylate, C6H1002. .......................Ethyl propionate, C5HIoO2 ......................up-Dibromopropyl alcohol, CH2Br.CHBr.CH2.0H. .Ethyl and phenyl bromidesnibromhydrocinnamic acidEthyl &'-dibromopropionateBromine on benzene .......Acetylene tetrabromide andFrom storax ..............Cinnttmic acid and methylCinnamic acid and ethylCiiinamic acid and propjlCinnamic acid and sodiumwith sodium.and potash.and potash.zinc.alcohol.alcohol.alcohol.amalgam.As methyl cinnamate.. .....As propyl cinnamate.. ..... As ethyl cinn'imate ........Methyl dibromopropionatewith zinc and sulphuricacid.As the methyl salt.........do. do. .........Silver propiunate and ethylAlly1 alcohol and bromine.. . iodide.8.61729.50699.72758.33689.91036'9205'7.50098.0078.41527.004s8.55159.25049.309813-5891 12.41411.5841 7'403TABLE I.--continued.Name of Substance.Ethyl aB-dibromopropionate, CH2Br.CHBr.COOEt.Dimethyl oxalate, COOMe.COOMe ...............Ethyl oxalate, COOEt.COOEt.. .................Methyl ethyl succinate, C7H,20q ................Diethyl succinate, C,H,,O, .....................Trimethjl phosphate, Me3P04 ...................Ethyl dimethyl phosphate, EtMe,PO, ............~ ~~Method of Preparation.~Oxidation of above com-pound with nitric acid,and then treated withmethyl alcohol.As the methyl salt ........--Silver ethyl succinate andmethyl iodide.Silver succinate and ethyliodide, succinic acid andalcohol.Silver phosphate and methyliodide.Silver dimeth;pl phosphateand ethyl iodide.~~089989.9111.99110.0309.194610.354110.5169.526GENERAL AND PHYSICAL CHEMISTRY. 11mirror to exclude errors of parallax. The boiling points were deter-mined by Kopp and Pawlewski's methods. The tables on pp. 9,10 and 11, contain a summary of the author's results. In Table I aregiven the reagents by which the several compounds were obtained,and the experimental values for b-*, cV9 in the general equationV = 1 + at + bt2 + ct3, representing the expansion of volume forincrease of temperature.I n Table I1 are the boiling points, sp. gr.a t 0" and a t boiling.point, and the specific volumes deduced from thedata.TABLE 11.Name of Substance,Ethylbenzene ...............PhenylethJlene .............P henyla ce t ylene .............Phenyl bromide.. ............Methyl cinnamate.. ..........Acetylene dibromide. .........Cinnainic acid ...............Ethyl ..............Propyl ..............Yhenylpropionic acid .........Methyl phenylpropionate .....Ethyl phenylpropionate ......Propjl phenylpropionate .....Methyl acrylate.. ............Propyl ................n/?-Dibromopropyl alcohol ....Ethyl propionate.. ...........Methyl ap-dibrom opropionate. .Ethyl ................Ethyl- ...Propyl- ...,,,,Methyl oxalate.. .............Ethyl ................Dimethyl succinate ...........Mcthyl ethyl .............TrimethTl phosphate .........Dimethyl ethyl phosphate. ....Diethyl .............Boilingpoint.136 *5146 '2141 -6153 -6109 -4300259 '627 1285 '1279 ' 8336 -6248 -1262 *180 -398 -5122.921998 -3205 '8214 *6233163 '3186195 -2208 '2215.4197 '2203 -33p. gr. at 0".--0.883160.92510 -946581 -52032 -29831 -03641 -041 51 -06621 -04352.071151 -04731 '03481 -01 520 93788C1 -939280 *919962 -16820.912241 -97771 -82791 -70141 *15791 -1031 *11621 -09251 * 05921 -23781 '1752Sp. gr. atb. p.0 -76120 -79140 -80321 *3082 -03520 -909740 -838880 *821430 -79170 * 87800 %38240 -801820 -778860 2371940 -819700 *78471.75350 -794721-6141 -45541 -33911 -00390 -876520 -9120-864820 -827261 -00190 -95188Specificvolume.--138 -93131 *11125 -8119 -791 '72162 -29188.17213 9 5239 -4.3170 -44195 -19221 -48245 *9698 -4121 -71x4*4 -95123 *96128 *06151 -99178 *14204 -09117 -26166 * i 8159 '72184 *58209 -85139 -45161 -45Homologous Compounds.-On comparing the specific volumes ofhomologous compounds uf analogoiis composition, it is found thatthe difference of specific volume for every CH, is very variable. I n.the case of the ethereal salts of phosphoric acid, the differenceis equal to Kopp's average value, 22; for the alkyl sa81ts of theacids of the acetic and acrylic series, the difference is rather greaterthan 23 ; for those of the succinic, phenylpropionic, and acrylic acidsit varies from 25-96. In the homologous alcohols, the specificvolume for the CH, group is about 20.Although the volume forCHz varies with different series of compounds, yet it is practicall12 ABSTRACTS OF CHEMICAL PAPERS.constant for various alkyl salta of one and the same acid, althoughnot for corresponding ethereal salts of homologous acids. Thus, forexample, the volume difference between ethyl oxalate and methylethyl succinate is not equal to that between methyl ethyl and ethylsuccinate. Facts such as these cause questions to be raised as to theprecise definition of homologous compounds.Isologous Compounds.- Similarly on comparing the results ob-tained for saturated and unsaturated compounds, the difference inspecific volume for H2 or nH, varies from 5 to 9 or some multiple ofthese numbers. The observations of the author in this respect are inaccordance with those of Buff, Zander, and Schiff.Thorpe assigned the number 5348 as the molecular volume ofbromine (this Journal, Trans., 1880, 384) ; in the author's results,differences of Br, in isologous compounds, as ally1 and dibromopropylalcohols, correspond with differences of specific volume varying from4996 to 59.14. Similar variations in the differences of specificvolume corresponding with uniform differences of C6H4 and C2H2Br2in the molecule are also observable.The specific volume values of the aromatic compounds examined bythe author were found t o be greater than the values calculated accord-ing to Kopp's general rules.V. H. V.Law O€ Smallest Volumes. By W. M~LLER-ERZBACH (Annalen,221, 125-132) .-In this communication, the author adduces furtherarguments in support of his law that in any chemical reaction theelements tend to arrange themselves in those forms of combinationwhich occupy the smdlest volume, or that greater condensation iscorrelated with greater affinity (comp. Abstr., 1882, 137, 451, 1G24).For example, the sum of the volumes of the trichlorides of phos-phorus and boron plus three atoms of bromine, or of silicon tetrachlo-ride plus four atoms of bromine, is greater than the sum of thevolumes of the tribromides of phosphorus and boron plus three atomsof chlorine, or of silicon tetrabromide plus four atoms of chlorine.Again, the experiments of Kammerer (Aniz.Phys. Chem., 138,290) have proved that hydrated chloric acid, HC1O,,7H2O, occupiesa molecular volume of 164.4, and hydrated iodic acid, H20,,9H20, of158.9 ; if to the molecular volume of chloric acid the number 36, orthe molecular volume of two molecules of water be added, the volumesof chloric and iodic acid will be in the ratio of 200 to 159. Accord-ing to the author's law, iodic should be more stable than chloric acid,and the experiments of Serullas have shown that an aqueous solutionof the former decomposes a t 40°, whilst those of Gay-Lussxc provethat only a partial decomposition of an aqueous solution of the lattercommences at 200".Kremers has demonstrated that there is an in-crease of volume when potash and soda are neutralised with nitric,hydrochloric, and sulphuric acids. The author has pointed out thatthis apparent discrepancy from his law may be explained by thegreater affinity of the molecules of water for the acid and the alkalion the one hand than for the resdtant salt on the other. Thus anexpansion instead of a contraction is the final result. I n this con-nection, the author cites the experiments of Ostwald, who proved thaGENERAL AND PHYSICAL CHEMISTRY. 13the volume occupied by a given weight of water containing in solutionan equivalent of potash is less than that occnpied by the same weightof water plus one equivalent of potash taken separately. The sameresult holds good in the case of sulphuric acid and water.Hence itmay be stated that the result of the neutralisation of potash and sodawith nitric, hydrochloric, and sulphuric acids is a contraction ofvolume, but that this contraction is so masked by the presence oflarge quantities of water that an expansion is the final result.V. H. V.Method of Correcting the Weight of a Body for the Buoyancyof the Atmosphere when the Volume is Unknown. By J. P.COORE (Chem. News, 48, 39--41).-1t is well known that correctionsfor the biioyancy of the atmosphere are seldom made because of thegreat trouble attached to obtaining the required data, and from them thenecessary correction.The author proposes to obviate these difficultiesin the following manner :-Assuming that the atmosphere within thebalance-case is dry, easily effected by open vessels of strong sulphuricacid, the only corrections required are for temperature and pressure.To effect this the author fixes on two standards, viz., 30 inches for thebarometric pressure, and 27" C. (= 300" on the so-called " absolutescale '7 for temperature : hence a variation of &th of an inch fromthis standard will cause a change of a+a in the resultant effect of thebuoyancy of the air on the load and its counterpoise, and according t othe law of Charles, the variation of 1" from 27" C. produces a similarchange.With these standards, corrections for temperature are made byreducing the barometric pressure to 27" C., and then by takingweighings of the object for which the correction is required undervarying conditions of temperature and pressure : the difference inweight corresponding to &th of an inch variation in the barometer iseasily found, and a constant for the object weighed is obtained bywhich the weights can be readily reduced to the standard 30-inchbarometric pressure, after having reduced them to the standard tem-perature, 27°C.It is simply necessary to multiply the differencebetween 300 and the reduced barometric pressure, and add or subtractthe product, as the case may be, from the observed weights. Anexample, chosen from an observation made by the author, will illus-trate the mode of working. In the first column of the subjoinedtable the weights of the same object are given under the varyingconditions registered in the subsequent columns, and in the lastcolumn the results of the application of the constant are given (thereare 15 observations in the original) :-HeightWeight Temperature of bar. in Heightof object. of balance ik ins. reduced. Result.a7.3447 23.5" C. 297.6 301.1 8 7.345187-3419 22.6 305.2 309.6 87.345187.3464 29.4 297.9 295.5 87.34514 ABSTRACTS OF CHEMICAL PAPERS.Greatest weight 87.3464 Barometer highest 309.6Smallest ,, 87.3419 7 ? lowest 295.5Differences 00.0045 14.1-:. Constant = 4.5 mgrms. i 14.1 = 0.319 mgrm.I n this way, the relative weight of even large vessels can be obtainedto a, &th milligram ; of course there is a limit to the accuracy ; how-ever it is noteworthy that the accuracy of the method is proportionalto the requirement, for the greater the bulk of the load, the moreaccurately can the " constant " be found. Great precision is requiredfor measuring temperatures and pressures in the case of loads of largevolume.From the data obtained by these observations and from the knomirnormal density of the air, the volume of the object can be calculated,and therefore the same constant may be made t o serve roughly forany given volume; thus in the case cited abore the volume of theobject exceeds that of the weights by 75 c.c., and the weight varies0.3 mgrm. for 1" C., or &th inch pressure. Hence with a difference ofvolume = 100 C.C. the weight would vary 0.4 mgrm. f o r 1' C., 6r &inchpressure, and so on. It is obvious that if the volume of the load wasvery large, the balance might be used for measuring the variations inatmospheric pressure and temperature, D. A. L