69 General and P h y s i c a l Chemistry. Relative Intensity of the Spectral Lines of Hydrogen and Nitrogen; its Bearing on the Conqtitution of Nebulae. By C. FIEVEZ (Anrt. Chim. Phys. [5], 20, 179-1 85).-Observations by Huggins have shown that in the spectra of certain nebulte there exists only one nitrogen line and one hydrogen line, and further researches by the same physicist have proved that the complex spectrum of nitrogen .can be readily simplified by merely diminishing its intensity, so that it is possible to extinguish a portion of the luminous rays, and to leave visible only those which are observable in the nebular spectrum. Adopting a method similar to that originally devised by Huggins, the author has also succeeded in showing that if the hydrogen spectrum be reduced in intensity, the line F, which corresponds with that of the nebuh, will alone remain visible after the C and other more refrangible lines have become too weak t o affect the eye.The method employed consisted in projecting by means of a lens a real image of the luminous body on the slit of the,spectroscope, and after- wards altering the intensity of this image, either by diminishing the aperture of the lens used for projection, or by placing a diaphragm with a circular opening between the lens and the image. The hydrogen tube was one of Plucker's, entirely covered with lamp-black: with the exception of a small portion of the contracted part, and was placed vertically before the projection lens. The dis- kames from the tube to the lens arid from the latter to the slit were arranged in such a manner that the projected image was narrower than the length of the slit, so that the luminous pencil, after it had passed through the slit, was received in its entirety upon the objective of the spectroscope. This arrangement, which is due to Lockyer, enables the observer to distinguish between long and short lines.With a powerful induction coil and condenser arranged for tension, and with a six-prism spectroscope, the hydrogen lines C, F, and H, are perfectly visible ; the hminous pencil was then narrowed gradually by means of a diaphragm of Of!07 meter aperture, by withdrawing the diaphragm from the slit and bringing it nearer to the lens. The length of the lines was seen to diminish, and the H line finally became invisible, whilst the other two lines still remained brilliant.With a diaphragm of 0.002 meter aperture the C line also disappeared, leaving the F line alone visible. With a small induction coil without a con- denser, and a two-prism spectroscope, the same results may be obtained, but less rapidly than with more powerful instruments. The line spectrum of nitrogen, called also a spectrum of the second order, is formed of several groups of lines indicated by Plucker by the numerals 1, 2, 3, 4, and 5. With the large coil and spectroscope, and a 0.007 meter diaphragm as before, the groups 1, 3, 5, 2, successively g VOL. XL.70 ABSTRACTS OF CHEMICAL PAPERS. disappear, and group 4 is extinguished, with the exception of the double line coinciding with that of the nebuh.If, while the experiment is proceeding, and when a line or group of lines have just been rendered invisible, the width of the slit of the spectroscope be slightly increased, the extinguished line immediately reappears, thus showing plainly that the disappearance is due, as was anticipated, to the weakening of the luminous iutcnsity of the ray. We are therefore at liberty to consider with Huggins that certain nebula do contain nitrogen and hydrogen among their constituent elements, referring the relative invisibility of the other rays to the absorptive action of space. J. W. Fluorescence. By 0. LUBARSCH (Aim. Phys. Chem. [2], 11, 46-69) .-The paper describes the author’s researches ou fluorescencei in which he has repeated the experiments of Eagenbach with certain modifications in the spectroscopic apparatus, whereby light of greater homogeneity is obtained.From the numerous experiments and observations adduced in the paper, the author’s conclusion is that Stokes’s law can no longer be maintained as a universally valid prin- ciple. R. R. Thermia Theory of Electricity. By J. L. HOORWEG (Ann. Phys. Chem. [2], 11, 133--155).-1n tbis paper, the author continues to adduce experiments and reasonings in support of the view which regards the molecular motion of heat as the source of electrical energy. He conceives that when any disturbance of the motions of the mole- cules occasions a loss of their vis viva, an equivalent quantity of elec- tricity appears. Among the propositions discussed are the following :- The division of bodies into classes, according as their conductivity is distinguished as metallic or electrolytic, is artificial. A current arises when a t least one of the substances in a closed circuit has its con- ductivity increased by rise of temperature.The electricity of friction and pressure arises from the contact of heterogeneous substances, by which the loss of molecular vis viva is occasioned. Friction simply increases the intimacy of the contact by multiplying the points at which the bodies touch, and it unequally raises the temperature of both substances, thus producing conditions which co-operate in aug- menting the effect. The electricity of friction and pressure has the same origin as that of the pile, viz., a disturbance of the molecules occasioning a loss of their vis viva.The theory is applied to pyro- electricity, thermo-electricity, and the electrical phenomena observed in evaporation, solidification, solution, cleavage, division, osmose, and capillary acttion. R. R. Discharge of Electricity in Gases and High Vacua. By F. NARR (Ann. Phys. Ohem., 11, 155--163).-The paper describes experiments in continuation of a former research on the passage of electricity through the vacua obtained by the Sprengel mercury pump. Glass tubes were not employed on account of their uncertain and changeable electrical properties, the vessel used being a hollow brass sphere. The resnlts appear to shorn that electricity traversesQENERAL AND PHYSICAL CHEMISTRY. 71 C E = - . I) Condensa- tion. 1 *49 1 ‘36 1 .17 1 -76 1 -34 0 9 7 1.38 1.05 --- the gas-vacuum, but the author remits their full discussion to a forth- coming communication.R. R. A. 1 sp. gr. Observer. - --_- 2.20 Clarke 2 .78 do. 1.998 Kremer 3-10 Clarke 3-49 do. 3 -94 Knight 5 .98 Fullerton 3.02 do. Electrical Conductivity of Saline Solutions. By J. H. LONG (Ann. Phys. Chem. [Z], 11, 37--46).-The author has continued the investigations of Rohlrausch on the conductivity of saline solutions at different temperatures and states of concentration. The salts exa- mined were the chlorides of manganese and zinc, and the nitrates of copper, strontium, and lead. The results, of which tables and graphic representations are given, are discussed in relation to the observations of other experimenters. R. R. Vapour-tensions of Homologous Series and Kopp’s Law of ‘Constant Difference of Boiling Points. By A.W~NKELMAN By U. D~HRING (Ann. Phys. Chem. [ Z ] , 11, 163--170).-The correctness of a law brought forward by the author having been questioned by A. Winkel- man (ibid. [Z], 9, 391), the present paper is devoted to its defence. The law in dispute maybe represented (Annalen, 204, 251-264). The Law of Corresponding Boiling Points. the equation- B. weight. 120.9 165 ‘4 42 ‘5 87.0 134.0 183 ‘0 366 .O ~ 0 1 . - 212.4 t’,) - t’, - qr tp’ - tp 4 - - where tp and 4’ are the boiling points of a liquid under the pressures p and p’ respectively, and t;l and t;l’ those of another liquid under the same pressures, while q and 4’ are constants depending upon the two liquids. R. R. Volume Relations of some HaloYd Salts.By W. MGLLXR ERZBACH (Ber., 13, 1658-1660) .-The author has previously pointed out that the contraction taking place when chlorine, bromine, and iodine combine with metals is most considerable in t’he case of chlorine, and least with iodine. He now confirms his prerious observations by cal- culating the contraction from a number of new data obtained by various observers. These are given in the following table :- Name of salt. RbCl . . . RbBr.. RbI . . . . LiC1.. . . LiBr . . . LiI.. . . . CdI,. . . . CdC12. # . - C. Calc. volume. 81 -7 81 .7 81 *’7 37’4 37 *4 37 -4 64 *2 64 *2 - B D = -. A Volnme found. 55 .o 59 ‘8 70 ‘0 21 ‘2 28 -1 38 *5 46 -5 61 -0 C-D C Contrac- tion. 0 9 2 0.27 0 -14 0 -4.3 0 -25 - 0 ‘03 0.27 0 *05 F =-. --- 0. H. 9 269General and P h y s i c a l Chemistry.Relative Intensity of the Spectral Lines of Hydrogen andNitrogen; its Bearing on the Conqtitution of Nebulae.ByC. FIEVEZ (Anrt. Chim. Phys. [5], 20, 179-1 85).-Observations byHuggins have shown that in the spectra of certain nebulte thereexists only one nitrogen line and one hydrogen line, and furtherresearches by the same physicist have proved that the complexspectrum of nitrogen .can be readily simplified by merely diminishingits intensity, so that it is possible to extinguish a portion of theluminous rays, and to leave visible only those which are observable inthe nebular spectrum.Adopting a method similar to that originally devised by Huggins,the author has also succeeded in showing that if the hydrogenspectrum be reduced in intensity, the line F, which corresponds withthat of the nebuh, will alone remain visible after the C and othermore refrangible lines have become too weak t o affect the eye.Themethod employed consisted in projecting by means of a lens a realimage of the luminous body on the slit of the,spectroscope, and after-wards altering the intensity of this image, either by diminishing theaperture of the lens used for projection, or by placing a diaphragmwith a circular opening between the lens and the image.The hydrogen tube was one of Plucker's, entirely covered withlamp-black: with the exception of a small portion of the contractedpart, and was placed vertically before the projection lens. The dis-kames from the tube to the lens arid from the latter to the slit werearranged in such a manner that the projected image was narrowerthan the length of the slit, so that the luminous pencil, after it hadpassed through the slit, was received in its entirety upon the objectiveof the spectroscope.This arrangement, which is due to Lockyer,enables the observer to distinguish between long and short lines.With a powerful induction coil and condenser arranged for tension,and with a six-prism spectroscope, the hydrogen lines C, F, and H,are perfectly visible ; the hminous pencil was then narrowed graduallyby means of a diaphragm of Of!07 meter aperture, by withdrawing thediaphragm from the slit and bringing it nearer to the lens. Thelength of the lines was seen to diminish, and the H line finally becameinvisible, whilst the other two lines still remained brilliant. With adiaphragm of 0.002 meter aperture the C line also disappeared, leavingthe F line alone visible.With a small induction coil without a con-denser, and a two-prism spectroscope, the same results may be obtained,but less rapidly than with more powerful instruments.The line spectrum of nitrogen, called also a spectrum of the secondorder, is formed of several groups of lines indicated by Plucker by thenumerals 1, 2, 3, 4, and 5. With the large coil and spectroscope, anda 0.007 meter diaphragm as before, the groups 1, 3, 5, 2, successivelyg VOL. XL70 ABSTRACTS OF CHEMICAL PAPERS.disappear, and group 4 is extinguished, with the exception of the doubleline coinciding with that of the nebuh.If, while the experiment isproceeding, and when a line or group of lines have just been renderedinvisible, the width of the slit of the spectroscope be slightly increased,the extinguished line immediately reappears, thus showing plainlythat the disappearance is due, as was anticipated, to the weakening ofthe luminous iutcnsity of the ray. We are therefore at liberty toconsider with Huggins that certain nebula do contain nitrogen andhydrogen among their constituent elements, referring the relativeinvisibility of the other rays to the absorptive action of space.J. W.Fluorescence. By 0. LUBARSCH (Aim. Phys. Chem. [2], 11,46-69) .-The paper describes the author’s researches ou fluorescenceiin which he has repeated the experiments of Eagenbach with certainmodifications in the spectroscopic apparatus, whereby light of greaterhomogeneity is obtained.From the numerous experiments andobservations adduced in the paper, the author’s conclusion is thatStokes’s law can no longer be maintained as a universally valid prin-ciple. R. R.Thermia Theory of Electricity. By J. L. HOORWEG (Ann. Phys.Chem. [2], 11, 133--155).-1n tbis paper, the author continues toadduce experiments and reasonings in support of the view whichregards the molecular motion of heat as the source of electrical energy.He conceives that when any disturbance of the motions of the mole-cules occasions a loss of their vis viva, an equivalent quantity of elec-tricity appears. Among the propositions discussed are the following :-The division of bodies into classes, according as their conductivity isdistinguished as metallic or electrolytic, is artificial.A current ariseswhen a t least one of the substances in a closed circuit has its con-ductivity increased by rise of temperature. The electricity of frictionand pressure arises from the contact of heterogeneous substances,by which the loss of molecular vis viva is occasioned. Friction simplyincreases the intimacy of the contact by multiplying the points atwhich the bodies touch, and it unequally raises the temperature ofboth substances, thus producing conditions which co-operate in aug-menting the effect. The electricity of friction and pressure has thesame origin as that of the pile, viz., a disturbance of the moleculesoccasioning a loss of their vis viva.The theory is applied to pyro-electricity, thermo-electricity, and the electrical phenomena observedin evaporation, solidification, solution, cleavage, division, osmose, andcapillary acttion. R. R.Discharge of Electricity in Gases and High Vacua. ByF. NARR (Ann. Phys. Ohem., 11, 155--163).-The paper describesexperiments in continuation of a former research on the passage ofelectricity through the vacua obtained by the Sprengel mercury pump.Glass tubes were not employed on account of their uncertain andchangeable electrical properties, the vessel used being a hollowbrass sphere. The resnlts appear to shorn that electricity traverseQENERAL AND PHYSICAL CHEMISTRY.71C E = - .I)Condensa-tion.1 *491 ‘361 .171 -761 -340 9 71.381.05---the gas-vacuum, but the author remits their full discussion to a forth-coming communication. R. R.A. 1sp. gr. Observer.- --_-2.20 Clarke2 .78 do.1.998 Kremer3-10 Clarke3-49 do.3 -94 Knight5 .98 Fullerton3.02 do.Electrical Conductivity of Saline Solutions. By J. H. LONG(Ann. Phys. Chem. [Z], 11, 37--46).-The author has continued theinvestigations of Rohlrausch on the conductivity of saline solutions atdifferent temperatures and states of concentration. The salts exa-mined were the chlorides of manganese and zinc, and the nitrates ofcopper, strontium, and lead. The results, of which tables and graphicrepresentations are given, are discussed in relation to the observationsof other experimenters.R. R.Vapour-tensions of Homologous Series and Kopp’s Law of‘Constant Difference of Boiling Points. By A. W~NKELMANBy U. D~HRING(Ann. Phys. Chem. [ Z ] , 11, 163--170).-The correctness of a lawbrought forward by the author having been questioned by A. Winkel-man (ibid. [Z], 9, 391), the present paper is devoted to its defence.The law in dispute maybe represented(Annalen, 204, 251-264).The Law of Corresponding Boiling Points.the equation-B.weight.120.9165 ‘442 ‘587.0134.0183 ‘0366 .O~ 0 1 .-212.4t’,) - t’, - qrtp’ - tp 4- -where tp and 4’ are the boiling points of a liquid under the pressuresp and p’ respectively, and t;l and t;l’ those of another liquid under thesame pressures, while q and 4’ are constants depending upon the twoliquids. R. R.Volume Relations of some HaloYd Salts. By W. MGLLXRERZBACH (Ber., 13, 1658-1660) .-The author has previously pointedout that the contraction taking place when chlorine, bromine, and iodinecombine with metals is most considerable in t’he case of chlorine, andleast with iodine. He now confirms his prerious observations by cal-culating the contraction from a number of new data obtained byvarious observers. These are given in the following table :-Name ofsalt.RbCl . . .RbBr..RbI . . . .LiC1.. . .LiBr . . .LiI.. . . .CdI,. . . . CdC12. # . -C.Calc.volume.81 -781 .781 *’737’437 *437 -464 *264 *2 -B D = -. AVolnmefound.55 .o59 ‘870 ‘021 ‘228 -138 *546 -561 -0C-DCContrac-tion.0 9 20.270 -140 -4.30 -25- 0 ‘030.270 *05F =-.---0. H.9