30 ABSTRACTS OF CHEMICAL PAPERS PUBLISHED IN BRITISH AND FOREIGN JOURNALS. General and Physical Chemistry. Action of differently Refrangible Rays on Iodide and Bromide of Silver. By E. B E CQUE RE L (Compt. rend. lxxix 185-190). WHENa sensitive photographic plate prepared in the ordinary manner with silver iodide and collodion is exposed for a short time to the solar spectrum the image when developed by pyrogallic acid is found to extend only from the violet to between F and G. But if a little chlorophyll is added to the collodion employed the plate under the same conditions shows also a feeble but well-defined action ex- tending from E to beyond B in the red with a remarkable and strongly marked band of maximum effect between c and B. The photographie action in this .band is however much weaker than that which Oakes place in the violet and attains the intensity of the latter only when the red end is exposed from five to ten times as long as the violet.Other much less st'rongly marked bands may be perceived between E and B. The author finds that the conspicuous band between c and D coincides in position and limits with the characteristic absorption-band of chlorophyll as he observed it in the collodion solutions made use of in preparing tlie plates. The colouring matter on the photographic plates obviously does not act as a screen cutting off the absorbed rays for in that case the contrary effect would be produced ; but we may explain the phenomenon by supposing that the silver salt is so con-nected with the chlorophyll that.an action set up in the latter by the rays it absorbs communicates an i~mpulse to the former by virtue of the intimate association of their particles. The author long ago showed that when sensitive plates are exposed for an instant to sunlight before submitting them to the spectrum the range of the chemical action is greatly extended towards the less re-frangible end. These earlier observations are rea,dily explained by the results above described. We may suppose the exposure to operate by producing a change of the colour or other physical condition of the upper film of the plate by which its absorptive power for the different rays is altered. R. R. The Electric Conductivity of Fused Salts. By F. BRAUN (Deut.Chem. Ges. Ber. vii 958-962.) THEauthor has determined the conductivity of the following salts at temperatures as little as possible above their fusing points in order t,o GENERAL AND PHYSICAL CHEJIISTRY. 31 ascertain whether any connection can be established between this and other physical constants. 3pecific con- Specific Constants of Molecular ductivity. gravity capillarity. Molecular volume at Hg = 100 ,tfusing weight. fusing millions. point. rl"" point. a2 -__ ---PbCI,. ............ 32200 5.802* -278 47 -9 NaNO ........... 114.75 1.878 8 *03 8.55 85 45 -3 AgNO ........... 8688 4 '355* -170 33.8 , just solidified. 4120 -KC1.. ............ -1.612 '7 *06 8.76 74*5 46 *2 NaCl ............. 8660 1.612 6 -78 8 '41 58 -5 36 -3 KNO ............6500 1*702 '7 *11 8 *35 101 59 .3 KI ............... -2 -497 6.04 4 '84 166 66 *5 NaaSOd-. ........... 3680 2 *lo4 18 55 L7 -64 119 56 *6 SrCl ............. 2260 2 mo 11.33 8.18 158 -5 57 '2 Na,CO .......... -2 *041 18.25 17.88 106 51 *9 K&O,. ........... 2150 2 .oo 16 *33 16.33 138 69 -0 -ZnC1 just fused. .. 85 .9 --136 *2 , just solidified. 8 -68 ---* Specific gravity at 0". a denotes the constant of capillarity OP the tangential force which in consequence of the opposite attraction of the liquid molecules is exerted on a line 1mm. long of the surface molecules. 2a a2denotes &uincke's specific cohesion = -,c being the specific gravity. a The numbers show that the expected connection cannot be traced.They show further that while the electric conductivity of fused salts is of the same order of magnitude as that of saline solutions it is gene-rally rather higher in the former case than in the latter. The case of zinc chloride is the most remarkable. Not only is it the widest removed from lead chloride to which fi-om the chemical resentblance between them it might be expected to approximate but in the fused state it has a lower conductivity than its own aqueous solution. The absence of any recopisable connection between the conductivity of fused salts and that of their solutions indicates that salts do not enter into solution with the same properties as they possess in the anhydrous state but that new molecules are formed possessing their own specific conductivity.M.J. S. The Heat of Formation of the Phosphorus Acids. By J. THOMSEN (Deut. Chem. Ges. Ber. vii 996-1002). THEfollowing results are given all of them refer to normal phos-phorus to 1gram-molecule of the respective acids and to reactions taking place at 18"-19" :- ABSTRACTS OF CHEMICAL PAPERS. Melting point. Heat of fusion. H3PO4 38.6' 2520 gram-degrees. H3PO3 70.1" 3070 9 ape 17.4O 2400 Heat of Solution &a ?Vder. Crystalline Acid. Liquid Acid. (H3PO4,Aq) + 2690 5210 (H3PO3,Ay) -130 2940 (H3PO2,Aq) -200 2200 Heat qf Formadiofi of the Acids from their E1eiiierzt.s. Crystalline Acids. Liquid Acids. (H3,F04) 302560 300040 (H3,P,O3) 227680 224610 (H3,P,02) 139950 137550 Aqzceozcs Solutions (H& O4,Aq) 305250 (H3,p,03,Aq) 227550 (H3,P,02 Aq) 139750 The steps in the determinations were (l),the oxidation of phos-phorus.This was performed by means of a solution of iodic acid of tlre strength HIo3+ 2400 H20. With a strong solution as used by Ditte Troost and Hautefeuille secondary reactions take place. In each experiment & molecule of HI03was completely reduced by the addit,ion of an excess of powdered normal phosphorus. It was found that each molecule of iodic acid oxidised 1.6 (1.602 to 1.63) atoms of phosphorus so that half of the iodic acid produced phosphorous acid and the other half phosphoric acid the two acids being formed in the ratio of 5 3. (2.) The oxidation of phosphorous and hypophosphorous acids to phosphoric which was best accomplished by the use of a large excess of bromine-water.Chlorine act,s more slowly. (3.) Determination of the heat of solution of the solid and liquid acids the difference between which gave the heat of fusion. M. J. S. The Heat of Formation of Arsenious and Arsenic Acids. By J. THOMSEN (Deut. Chem. Ges. Ber. vii 1002-1006). THEfollowing determinations made by processes differing from those employed by Favre in 1853,show nevertheless a very close agreement. The heat of solution of acnzorphows ASz03in water was ascertained by observing the difference in the heats evolved when powdered arsenious acid and its solution were respectively added to an excess of sodium hydrate The result (As203,Aq) = -7550 indicates that the anhy- dride dissolves as sz~chin water no hydrates being formed.The two GENERAL AND PHYSICAL CHEMJSTRY. hydrates of arsenic acid HlAs207and H3As04,were examined. The solution of the hydrate HiAs207,lowers the temperature from 18" to '2" but as it almost immediately begins to combine with water the temperature quickly rises again to 30" and if only the requisite ynan- tity of water has been used the whole solidifies to a mass of the hydrate H3As04. The oxidation of arsenious to arsenic acid was per- formed with iodine keeping the arsenious acid in excess. Metallic arsenic was oxidised with bromine-water. The following are the results for one molecule of the respective compounds at 18' :-(As20j,Aq) = -7550 gram-degrees. (hs205,Aq) = + GOO0 Heat of Solution... . *. (HjAsO4,Aq) = -400 7 , (HiAszO,,Aq) = + 1300 ? 77 Formation of Hydrates (As205,2H20) = 4.710 (As~O~,~H~O)6800 ,7 Formation of the Anhy- (As2,03) = 154590 f> drides { (As2,05) = 219400 9 (Asz,03,Aq) = 147040 9 99 Formation of the Acids (Ssz,05,Aq) = 225400 in Aqueous Solution (H3,As,04,Aq) = 215240 ?* (As,O,Aq 0,) = 78360 99 M. J. S. The Equivalence and Transformation of the Chemical Forces. (Compt. rend. Ixxix (CommissionReport.) By P. A. FAVRE 44244). FROM this memoir of If.Favre which embodies the substance of com- munications published during the last twenty years we learn that among other questions in connection with the correlation and equiva- lence of chemical and electro-dynamic work he has resolved the fol- lowing :-That the heat generated in the cell and that which results from the resistance of the metallic circuit are always complementary and furnish the total heat due to the sum of the chemical actions which take place; that the oxidation of the zinc alone is not sufficient to account for the thermic effects produced by tho current but that it is necessary to take into account also the heat of combination of the acid with zinc oxide or in other words that the reaction is correctly ex-pressed by the substitution of the hydrogen of the acid by metallic zinc.He explains the impossibility of effecting the decomposition of water wit<ha single zinc and platinum couple immersed in dilute sul-phuric acid; a result easily attained with a cell of Grove's arrange- ment.He also suggests an explanation of the apparent transfereiico of hydrogen in the electrolysis of sulpliuric acid. He shows that the chemical decompositions resulting from the passage of the elect-ric carrent always bring icto play the same quan-tities of heat as those which accompany similar decompositioiis effected by other influences and that he has t,hus been enabled to determino YOL. XSVIII 1) ABSTRACTS OF CHEMICAL PAPERS. the heat of combustion of a large iiiimber of metals unat,tackable by acids. Various experiments have induced him to conclude that the calorific movement and the electro-dynamic movement can be produced simul- taneously in the circuit without either movement necessarily involving the transformation of the other ; in fact that whatever be the tempe- rature of the circuit the quantity of heat which reverts to the pile is always equal to that which the pile throws off in the circnit in the electro-dynamic state.He also briefly touches the complex problem of the conductivity of liquids without electrolysis. J. W. On Gladstone's Experiments relating to Chemical Mass By EDMUND J. MILLS(Phil. Mag. [4],xlviii 241-24'7). INHarcourt and Esson's experiments on the time occupied in chemical reaction it was shown that when a substance undergoes chemical change the residue y of changing subsfance is connected with the unit-intervals x,of change by the equation y = a'~ -a'z & a"~-a"s where a represents the amount of suhstauce originally present and a the amount of it disappearing per unit of x.Many yeass previously Gladstone published the results of numerous experiments on " Cir-cumstances Modifying the action of Chemical Affinity," but did not succeed in deducing any relative mathematical expression from his observations. The author has applied Esson's equation to the re-actions previously observed by Gladstone and has obtained in this manner some very interesting results. Gladstone's experiments may be briefly summarised as follows :-For oiie " equivalent " of a ferric salt successive groups of equivalents of potassium sulphocyanate were added in presence of water and the amount of red salt thus produced was estimated by the colorimetric method.The total amount a of red salt produced represents therefore in special measure the original unexhausted energy of the ferric salt. Taking each unit of x (the value of which is seldom given in the original experiments) to represent 25 " equivalents " of sulphocyanate the equation becomes in the case of ferric nitrate y = 401 (*855)"+ 224 (~1516)". With ferric sulphate the equation is y = 438 (-8208)" + 132 (-140)") where the unit of x is 15 equivalents ; and with ferric chloride y = 406 (-89)" + 214 (.25)" the unit of t( representing 20 equivalents. The results calculated from the above equations are expressed in percentages of the initial value of y and the following are partial instances of the coincidences observed :- GENERAL AND PHYSICAL CHEMISTRY.~ ~ ~ ~~~~ Ferric Nitrate. Ferric Snlphate. Ferric chloride. 2. y calculated. y calculated. y found. y calculated. y found. ~---1 60 ’3 66.3 65 ‘3 66.9 65 ’0 2 47 ,7 52‘2 53 .9 54 *o 54 ‘0 i!i11 3 40.2 43 *6 44 -2 46 .7 46 *9 4 34 ‘3 34 ‘9 35.6 41 ‘2 41 *2 5 29.3 28 -5 28 ’6 28 *7 36 ‘6 36 ’8 6 25 *1 23 *7 32 *6 33 ‘2 24‘5 I 23 -5 Ferric citrate mixed with solutions of gallic acid or with potassium ferrocyanide gave similar results the number calculated from the equation coinciding with those obtained by experiment. The results show that while an ordinary equation such as + GKCNS = Fe,(CNS)G + 6KC1 may represent the result of dis-tributing weight it does not represent in any way the chemical energy of the reacting salts for in the present instance the energy of the quantity QFezC16 is not exhausted until about 400 units (KCNS) have been brought to bear upon it.It would be well therefore in making use of the word “ equivalent,” as in the expression “C is equivalent to Hp,” to bear in mind that H and C have never been com- pared as to the work they can do under certain circumstances and that the relations of their potential energies have yet to be determined. J. W. Researches on the Simultaneous Diffusion of Certain Salts. By C. MARIGNAC (Ann. Chim. Phys. [5],ii 546-581). INthis paper the author discusses the results and gives all the numeri- cal details of a very extensive series of experiments which he has conducted on exactly the same plan as Graham adopted in his cele- brated investigation.The present research is however directed to points only incidentally touched on by Graham and was undertaken with the design of throwing some light on the vexed question of thc existence in solution of double salts and with the hope also that rela- tions between the diffusibilities of salts might be deduced from their simultaneous diffusion out of one solution with greater precision than from direct experiments. The author confined his observations to pairs of salts incapable of acting chemically upon each other that is the two salts used had either both the same base or both the same acid In general equal weights of the two salts were employed. The time of the diffusion varied from four days to five weeks and no special precautions were taken to maintain the vessels at a uniform tempera- ture.It is pointed out that Graham’s figures merely express the relative weights of salts diffused in equal times from solutions of equal quan- tities and that no regard was paid to the change in the rate of diffusion which is constantly going on in consequence of the diffusion D2 ABSTRACTS OF CHEMICAL PAPERS. itself. For Graham showed that diffusion takes place in direct pro-portion to the quantity of salt contained in the liquid; the results observed by him must therefore be regarded as the integral effects of a constantly-diminishing rate of diffusion. Hence the ratio of the dif- fused quantities of the two salts is nearer unity than the figure which would express the ratio of their real diffusibilities.If the constantly diminishing quantity of the salts in the difhsing liquid were the only changing condition affecting the rate of the action it would be easy to determine the co-efficicnts of diffusion. But there are other modifying circumstances and in the absence of any means of estimating these a formula must be sought for empirically which will approximately satisfy the condition of giving a constant qumtity for the ratio of the co-eGcients of diffusion even when the duration of the experiment is made to vary within wide limits. The author has found such a formula in a logarithmic expression deduced from the assumption that the diffusion of each salt diminishes in proportion to twice the quantity diffused out.The ratio thus calculated of the co-efficient of diffusi- bility of the less diffusible salt to that of the more diffusible he terms the relative co-eficieid of simzsltsneous &fusion. The value of this co-efficient for some hundreds of cases' is given in tables contained in the paper but the author has not been able to elicit any general law except the abundant confirmation of Graham's observation that in all cases the mixture of two salts diminishes the diffusibility of the less diffusible. The nature of the results may be illustrated by the follow- ing figures which refer to the simultaneous diffusion of 4-67'grams of potassium chloride and an equal weight of barium chloride dissolved together in 31 grams of water :-Duration of the Experiment in Days.Quantities of the Salts Diffused. BaC12. 1 KC1. Direct Ratio of the Quantities Diffused. Relative Co-efficientof Simultaneous Diffusion. 4 0.2047 0 *4808 0.426 0 -398 5 0 '2712 0 *6165 0 *439 0 -403 7 0 -4260 0 '9116 0.467 0.407 10 0.408 By a special series of experiments made to determine these points it was found that the value of the relative co-efficient of simultaneous diffusion is not affected by variat'ions in the proportions of the two salts but that on the other hand the value does vary with the degree of concentration of the solution in a manner which cannot be referred to any general principle. In order to determine the influence of one salt in modifying by it's presence the diffusibility of another present in the same solution three diffusion-cells were prepared as much alike as possible.In two of these the salts compared were made to diffuse separately and in the third the same quantities of each salt were caused to diffuse simul- taneously. The effects of any slight disparities in the vessels were GENERAL AND PHYSICAL CHEiIIISTRY. eliminated by repeating each experiment. six times so that every Dossible combination of the solutions and the vessels came into play and the mean of the six determinations was taken. The results show that in the mixture of two salts the most marked and constant effect is a diminution of the diffusibility of t'he less diffusible salt while the diffusion of the other salt is in some cases increased and in others decreased in a smaller degree however than in the case of the less diffusible This mutual influence becomes less and less as the solu-tions are made more and more dilute and it might be supposed that the limit towards which dilution tends to bring the ratio of the co- efEcients in simultaneous diffusion woidd coincide with the ratio of the co-efficients in separate diffusion.So far is this from being the case that it was observed only in the following instances :-Potassium sodium and ammonium chlorides in presence of the corresponding nitrates ; sodium and ammonium chlorides ; potassium and ammonium nitrates ; sodium and potassium sulphates in presence of magnesium sulphate. Since when mixed in a dilute solution,.potassium sulphate and magnesium sulphate retain their own diffusibilities which have no relation to their equivalents it follows that there is no affinity between two salts in solution even when they are capable of forming a double salt hence such double salts are probably formed only at the moment of crystallisation from the solution. The author's conclusion is that although experiments on the simultaneous diffusion of salts may show us the relative order of their diffusibilities such experiments cannot in general give us the ratios of their real diffusibilities. The results obtained prove that acids and bases preserve a certain relative order of diffusibility in a11 their combinations and the radicals may be thus arranged in two series according to that order ; those among which the order has not been determined with certainty being grouped together in brackets :-Negative Tadicals.[Chlorine bromine iodine] ; nitric acid ; [chlo-ric perchloric and permanganic acids] ; fluorine ; chromic acid ; sulphuric acid ; carbonic acid. Positive radicaZs. Hydrogen ; [potassium ammonium] ; silver ; sodium ; [calcium strontium barium lead mercury] ; [man-ganese magnesium zinc ] ; copper ; aluminium. In no one case has the author been able to detect any traces of the separation of acids and bases by diffusion R.R. Suspension of Clay in Water. By W. DURHAM (Chemical News xxx 57). CLAYremains suspended in pure water for an indefinite time ; but if a few drops of acid be added to the water the power of suspension is destroyed.In solutions of sulphuric acid and sodium chloride the liquid clears in the order of the specific gravities of the solutions so that the densest liquid settles nnd clears last. Alkaline solutions hat-e the same power with the exception that the liquids clear in the inverse ABSTRACTS OF CHEXICAL PAPERS. order of the specific gravities. The suspension of the cIay is attributed by the author to electricity generated by the friction of the water against the solid particles. As water is a had conductor the differ- ence in potent,ial between the clay and the water continues for some time hence they are mutually attracted; but when acid or salt is added the liquid becomes a good conductor the potentials are equal-ised and the clay falls.With the alkali on the other hand although the liquid does become a better conductor it at the same time becomes a better generator of electricity and it is only when by adding a considerable quantity of alkali the conducting exceeds the generating power that the potentials are equalised and the clay falls. E. W. P. Determination of the Emissive Power of Black Bodies by means of the Ice-calorimeter. By A. LEHNEBACH (Pogg. Ann. cli 96). The Graphic Representation of Absorption-spectra. By K. VIERORDT (ibid. 119). Observations on Roiti’s paper u Is the Electric Current an Ether-current ? ” By E. EDLUND (ibid. 133). Determination of the Specific Heat of Air. By A. Kunz (ibid.,173). The Heat-conducting power of Mercury is independent of Tern-perature.By H. HERWIG (ibid. 177). On the Photography of the Diffraction-spectrum and the determination of the Wave-lengths of the Ultra-violet Rays. By H. DRAPER (ibid.,337). Preliminary Experiments to determine the relation between the variations of Density and Elasticity of Gas at Pressures less than one Atmosphere. By F. A. SILJESTROM (ibid. 451 573). Experimental Determination of the Dielectric Constants (ibid. 482 531). of Insulators. By F. KESSLER On a simple Euthyoptic Spectroscope. By F. KESSLER (ibid. 507). On the Hemimorphism pf Cane-sugar. By H. BAUMHAUER (ibid. 510). On the Heat of Mixtureand Specific Heat of Mixed Liquids. By A. WINKET~MANN (ibid. cl 592 ; cli 512j. On a Modification of Senarmont’s Method of determining the Isothermal Surfaces in Crystals.By At. C. RONTGEN (ibid. 603 ; clii 367). GENERAL AND PHYSICAL CHEMISTRY. 39 Apparatus for the safe Evolution and Combustion of Detonating Gas. By A. GAWALOVSKI (ibid. cli 628). KI Self-acting Washing Apparatus. By A. GAWALOVS(ibid., 630). Exsiccator for Drying in Rarefied Air without the use of the Air-pump. By A. GAWALOVSKI (ibid. 631). Filtration under Pressure. By A. GAWALOVSKJ (ibid.,632). On a Capillary Galvanoscope constructed by W. Siemens. (ibid.,639). A simple Law for the Development and Grouping of Crystal- zones. By G. JUNGHANN (Pogg. Ann. clii 68). On the Reflection of Light from the Surfaces of Isotropic Bodies. By G.LUNDQUIST (ibid.,177). Application of the Mechanical Equivalent of Heat to Molecular Forces Weight and Distance. By G. WEINBERG (Pogg. Ann. Erganzungsband,vi 586). On the Secondary Current. By K. W. KNOCHENHAUER (ibid. 302 607) Geometric Solution of some Electrical Problems. By E. PICKERING (ibid. 622). On Attraction and Repulsion accompanying Radiation. By W. CROOKES (Phil. Mag. [4],xlvjii 81). An Improvement in the Construction of the Spectroscope. By H. G. MADAN (ibid. 116). On Unilateral Conductivity. By A. SCHUSTER (ibid. 251). On an Absolute Galvanometer. By F. GUTHRIE (ibid.,296). On Electricity produced in Mechanical Actions. By L. JOULIN (Ann. Chim. Phys. [5] ii 5). Action of Electricity on Flames Solid Bodies and Gases. By V. NEPRENEUF (ibid.,433).