101 G e n e r a l a n d P h y s i c a l C h e m i s t r y . Existence of Oxygen in the Sun, and a New Theory of the Solar Spectrum. By H. DRAPER (Conzpt. rend., Ixxxv, 613- 614).-Uniting all the conditions for obtaining the best results, the author photographed simultaneously the spectrum of the sun and that of oxygen rendered incandescent bF the sparks of a Ruhmkorff coil. The photographs showed that the lines of the oxygen spectrum exactly coincided in position and relative intensity with certain bright lines in the solar spectrum, thus proving the existence of oxygen in the sun. The solar spectrum must therefore no longer be mgarded as a con- tinuous spectrum with no other than the absorption lines produced by metallic vapours ; it must be admitted that it also contains superim- posed lines and bands brighter than the field of the continuous spec- trum.These brighter lines may reveal the existence OP other non- metallic elements, and perhaps some of the so-called dark lines ought t o be regarded as merely intervals between the brighter lines. R. R. Transverse Absorption of Light. By W. AKEOY D (Chern. i?iTezos, xxxvi, 159).-1n a forrner paper (see this t J o z c ~ m d , i, 1877, 571), the author has pointed out the difference between structzcraZ and tramverse absorption. I n the present paper he describes a new method of obser- vation. The absorbing liquid is placed in a srn:ill glass trough, the ends of which are made of thin microscopic glass ; the light passes at right angles to the absorbing medium, and dispersion is eliminated ; the results are quantitative.The yrirLc$e of constancy of absorption is laid down, viz., a coilstarit number of molecules of a substance when similarly aggregated produces t h e same amount of transverse absorption. It is shown experimentally that a solution of potassium dichroniate gives the same amount of absorption as a plate of the solid itself con- taining the same amount of dichrome as was contained in the solution. The size of the particles producing isolated absorption-bands is approxi- mately determined for a few substances. The following numbers are given :- Incipient Width of molecular absorption. aggregate in mm. Potassium permanganate. ... 3 bands 80 Methylaiiiline violet ........ 1 band 63 Magenta.. ................ 1 ,, 47 Iodine green 1 9 9 .............. 480 The smaller the size of the particles in a given thickness of solid, the more readily do short wave radiations appear to be absorbed.M. 31. P, M. Conductivity of Electrolytes. By A. F. BE RGGBEN ( A ~ T L . Chi.,%. Plys. [ 21, i, 4C3!)-.510) .-‘l’he author used Pallzow’s method, described in the BerZin Jfoientsbericht (1868, p. 486). He found, however, th;at VOL. XXXIII. i102 ABSTRACTS OF CHEMICAL PAPERS. this method was applicable only to such fluids as did not react with the amalgamated zinc plates. After explaining in considerable detail the method employed, the author gives his results in ;I tabular form, the substances with which he experimented being normal and acid potassium sulphates, normal sodium sulphate, magnesium sulphate, normal ammonium sulphate, and sodium chloride.The results of these experiments are represented graphically in plate iii, fig. 4 of the volume. The condiictivity appears continuously either to increase or diminish with an increasing concentration of the solution in the different cases. I n the case of potassium sulphate the conductivity appears: to increase. Kohlrausch and Grotrian have found that in the case of potassium chloride, the relation between the conductivity and the percentage of salt in solution may be expressed by a straight line. The conductivity of sodium sulphate seems t o increase less rapidily with an increased per- centage of salt in solution than in the case of potassium sulphate. In ammonium sulphate the conductivity also increases with the balt per- centage, but appears to approach a maximum, as with a further increase in density of the solution no further increase in conductivity can be observed.The solution of magnesium sulphato which proves the hest con- ductor contains about 16 per cent. of salt, and thc conductivity was measured a t about 8" C. Acid potassium sulphate did not yield such regular results as the other salts. This the author conjectures may be due to impurities. It is, however, a better conductor than the normal salt. According to their conductivity, the sulphates may be arranged in the following order :--(NH&SO,, KIISO4, K2S04, Na2S04, and MgS04. Kohlrausch and Grot'rian have found the following order in the conductivity of the chlorides of the alkaline earths and alkalis:- (NH,)Cl, KC1, NaCI, LiCl, CaCl,, SrCl,, CaCI,, and MgC1,.Certain analogies, therefore, would appear to exist between the chlorides just mentioned and their corresponding sulphates. Among these salts, the solutions of which have a relatively high conductivity the ammonium salts rank highest. Kohlrausch and Grotrian foand a solution of ammonium chloride, the conductivity of which was almost half that of the best acid conductors. Wiedemann also has found that ammonium nitrate has a very high conductivity. The author's experiments show that ammonium sulp'hate has a con- ductivity considerably higher than that of any of the other sulphates investigated. The following table contains some determinations of the conductivity of solutions of potassium, sodium, ammonium, and magnesium chlo- rides compared with that of their corresponding sulphates in solution, the former being taken from Kohlrausch and Grotrian :-GENERAL AND PHYSICAL CHEMISTRY.103 Per cent. 5 5 5 10 15 20 5 10 - t. Substance. KC1 ........... NaCl .......... NH4Cl. ........ ........... ........... ........... MgClz ........ ........... 10SL. 520 486 696 1365 1980 2547 503 827 Substance. R2S04 ......... Na2S04 ........ (NH4)&304 ..... . . . . . . . . . . . . . . 9 9 ..... MgS04 ........ 10SL. 335 278 384 732 1036 1244 186 282 From this it may be easily seen that the alkaline. chlorides possess a higher conductivity than the corresponding sulphates. 5. M. T. Determination of the Electric Conductivity of certain Liquids with a Constant Current. By J. TOLLINGER (Ann.Chenz. Phys. [S], ii, 510--516).-The object of the author in these experiments has been, not so much to reinvestigate the conductivity of liquids already determined, as to test by constant currents the values found by Kohlrausch and Grotrian with varying currents. As difficnlt8ies and objections have been found to t,he use of troughs and strsight glass tubes in the experiments, the author employs a U-tube, and to obtain a more constant polarisation he uses as elec- trodes spirals of platinum wire, which have t'he further advantage of allowing any gas generated t o escape readily. The column of liquid to be tested was introduced, together with a rheostat, into one branch of a Wheatstone's bridge, whilst a similar tube with equal electrodes filled with the same liquid, as well as a rheostat, was placed in the other hranch, in order to eliminate small changes in polarisation due to changes of temperature and irregularities of the currents.The whole arrangement is shown in plate iv, fig. 1, of the volume. During the experiment the electrodes of the second tube, as well as the resistance selected, remain constant, while in the other branch of the bridge the electrodes are lengthened and shortened. To preserve a constant, temperature, a large water-bath was used, into which the whole apparatus was placed. With the exception of sulphuric acid, the liquids investigated by Kohlrausch were employed. In the fol- lowing table, so far as possible, Kohlrausch's results are compared with those of the author. Any differences between them may possibly be explained hy slight differences in the nature of the liyuids, arising from impurities.z' 2104 ABSTRACTS OF CHEMICAL PAPERS. 1.8364 1.8286 1 .7787 1 *2208 1 *1845 1 -2811 1.1681 1 -072 1 *3483 1 '013 1 -1862 1 '0912 1 1'7.5 94 '5 0 '150( 18 -3 92 '5 0 '150( 18 .I 84 '6 0 *150( 17 -9 50 '0 0 -3OOi 18 -2 17 *0 0.1491 18 -2 23 '1 0 *149( 18.4 15 '1 0 '1491 17.1 10 -0 0 -2991 18.1 34 -0 0 *299( 17 -3 2 -5 0 *149( 17.9 29 -7 0 *299( 18 -0 18 '3 0 '299( I&SOJ 77 ¶? Mg;O4 ZnSO, KHSO LiCl . HNO, HC1.. cuso, KzC03 107'2 99 -22 120 -87 28 *96 217 *08 213 -30 245 '00 140 *35 96.99 255 *4'7 27 -96 28-87 l 3 I 4 l 5 16'53 943 17.52 1018 15.30 836 18 -33 6978 18 -14 461 18 *74 471 19 '08 410 18.30 1440 17.55 2078 18.80 393 16 -48 7206 16 -17 69'79 6 7 8 9 10 11 12 cy I 0; I Conductivity k.18" 983 1033 927 6941 461 462 400 1436 21 00 386 7362 7182 Tollingcr. .. .. .. 457 460 396 1434 2086 383 7317 71443 980 1030 915 6912 451 452 .. .. 2121 7330 7174 + 0 - 3 + 0.3 + 1 ' 3 + 0.4 + 0.9 + 0.5 + 1.0 + 0.1 + 0.7 + 0.8 + 0.6 + 0 - 5 I From these results it mag be seen that the values found with con- stant and with induction currents do not differ materially. J. M. T. Specific Inductive Capacity. By V. NEPRENEUF (Compt. Tend., lxxxv, 547).-!I!he author's experiments relate t o the energy of the sparks which pass between the plaOes of a condenser when dielectrics of different kinds and thicknesses are interposed. The results confirm the established laws of electric induction. R. R. Thermoelectric Temperature Determinations.By R o SE N- THAT^ and MOLLER (Chem. Centr., 1877, 241).-The authors have applied a thermopile of copper and iron to the determination of ground temperatures for hygienic purposes. Specific Heat of Water according to the Investigations of W. Wunchhausen. By A. WULLNER (Am. Chem. Php. ['L], ii, 592-605) .-The author alludes fully to experiments by Pfaundler and Platter, Hirn, Jsmin and Amaury, Hess and Person, which do not quite agree with those of Regnault as to the equation for the specific heat of water between 0" and 100". These differences between the various experimenters have led the author t o institute a new series of investigations, the experimental part of which has been carried out by Munchhausen. A full description of the method employed and tables of the results found are given.The author regrets that Munchhausen was not able to continue his experiments between 70" and loo", but says that the cxperirnents between 1 7 and 70" suffice to indicate the direction taken by the specific heat between the latter temperatures. M. M. P. M.GENERAL AND PHYSICAL CHEMISTRY. 105 Calculated. From the numbers obtained, the author deduces the following for- mula for the specific heat at t. Ic = 1 + 0.00030192 t. A calculation of the observations with this value for the constant, gives the mean error of experiment as *0016 ; therefore, the probable error of ,00108. For comparison of the observations and calculations, Series I1 and VI are given. Observed. Series 11. A + 17 t 3 - 27 + 5 - 10 - 20 + 13 + 8 - 3 - 9 + 15 Series TI.Calculated. Observed. A - 13 + 7 + 8 t 4 - 23 - 21 4- 31 - 11 From these it may be seen that the differences are of the same order in both series, so that the equation fully represents the results of expe- riment. The uncertainty of the value of the coefficient of temperature as given by the probable error is 0.0000099 ; so t!hat the specific heat at t lies between k = 1 + 0.0002920 t and IG = 1 + 0*0003118 t. The author then does away with the objection that a perceptible loss of heat might be caused by the passage of the water added to the calorimeter, through the air, his arguments being based on the expe- riments of Dulong on the rate of cooling of water in air. The author concludes that between 0 and 70", or if it be permitted to go beyond actual experiment, between 0 and 100" also, the results obtained show that the specific heat increases more rapidly than Reg- nault's numbers, but much more slowly than those of Jainin and Amaury ; thus, k , according to the several experimenters, is as follows :- At 20" ......1.0060 1-0012 1.0235 ,, 40 ...... 1.0121 1.0030 1.0459 ,, 60 ...... 1.0181 1.0056 1 * 0 70 3 ,, 80 ...... 1.0241 1.0089 1.0957 ,, 100 ...... 1,0302 1.0130 1.1 220 Wiillner. Regnault. Jamin. According to the equation used by Jnmin and Amaury, the increase in the specific heat would be about €ourfold, and in the case of Xeg- nault's, little less than one-half that found by the author at 100". J. If. T.106 ABSTRACTS OF CHEMICAL PAPERS. Note by the Abstractor.-It is difficult to give an adequate idea of the author's argument without a translation of the first part of his paper and the tables in extenso, which would be beyond the limits of this Journal. Apparatus for Measuring the Heat of Vaporisation of Liquids.By M. B E R T HE L o T (Compt. mad., lxxxv, 646-648).- The liquid is distilled from a, flask-shaped glass vessel, the neck of which is, however, sealed a t the top, and near to this internally is the open extremity of a glass tube, which traverses the centre of the vessel, passing out through the bottjom. This tube is continued downwards from the bottom of the vessel for a short distance, and its lower extremity is adapted to a worm-tube wholly immerscd in the water of the calorimeter. The apparatus is figured in the paper, which also describes the mode of operating.Bp M. BERTHELOT (Con@ rend., Ixxxv, 648--651).-1n this paper the author shows the influence which differences in the physical states of a body may have in determinations of its heat of fusion. The states referred to are not isomeric modifications of the substances, but change, like those induced by the variable plasticity of resinous bodies. Very different values are obtained for hhe heat of fusion of chloral hydrate when the sample has been recently melted and then solidified, since this substance will even for days continue to retain some portion of its heat of fusion, and several months will be required for its return to st determinate thermal condition. R. R. Specific Heat and Latent Heat of Fusion of Platinum. By J.V I O L L E (Compt. rend., lxxxv, 543-546).-The paper describes the method adopted by the author for determinations of the spccific heat of platinum at high temperatures. The results lead to the following formula for the mean specific heat of platinum between 0" and to:- Cz = 0.0317 + 0*000006t, the superior limit being 1200". Between the same limits the true specific heat a t to is represented by yt = 0.317 + 0.000012t. Assuming these formulae to represent the specific heat of platinum up to the melting point, the author applies them to the ex- perimental results obtained with the fused metal, and arrives a t 1779" as the melting point of platinum, and 27.18 as its latent) heat of fusion. The data which are supplied by the author's experiments permit pla- tinum to be used in determinations of high-temperature melting points and speci6c heats of other substances.He has in this way obtained 954" as the melting point of pure silver. Contributions to Chemical Statics, By ERNST B R ~ C K E (Wierz. Akad. Bey., lxxv, 507--2;?2).-The author has studied the in- fluence of temperature, dilution, addition of acids, and condition of molecular aggregation on the coloured solution produced by adding salicylic acid to ferric chloride. The violet tint of iron salicylate is developed only in slightly acid solutions ; on cautiously neutralizing, a Burgundy wine tint is first developed, and then the solution becomes yellow or colourless. On boiling a solution prepared by adding sali- R. R. Determination of the Heat of Fusion. R. It.GENERAL AND PHYSICAL CHEMISTRY.107 cylic acid to ferric chloride until no alteration is produced by adding to the coloured liquid either a little ferric chloride or a little salicylic acid, the tint disappears to a greater or lesser extent, but is reproduced slowly on cooling and standing, so that after some days the colour is the same as before heating. Analogous results are obtained if the coloured liquid be acidified with small quantities of hydrochloric, phos- phoric, or sulphuric acid before heating ; the acid causes in the cold a greater or less lightening in tint according to the quantity added, complete decoloration ensuing after a certain amount is added. A dark-coloured solution, which has been partially lightened by addition of acid, is much less bleached on dilution with water than one of the same tint, but not containing acid; whilst a soliltion to which just enough acid has been added to destroy all the violet tint is rendered distinctly violet on adding distilled water.It is possiblc to use ferric salicylate as an indicator in titrnting sulphuric, nitric, and hydro- chloric acids, but it does not answer with organic acids such as oxalic, tartaric, acetic, &c. These acids act differently from the mineral acids so far as modifying the colour is concerned; thus, little or no effect is produced on heating a solution lightened in tint by oxnlic acid, and but little violet is produced on diluting a solution just bleached by oxalic acid. Citric, tartaric, and acetic and succinic acids produce the same result as hydrochloric acid on heating ( i e ., the solution is more or less decolorised, the tint reappearing on cooling). A much larger qnantity of acetic acid is, however, requisite then of hydrochloric acid, and so on with the others. Formic acid acts as oxalic acid, and not its acetic. The colouring matter of ferric salicylate is not suspended solid matter ; no settling takes place even on long standing ; moreover. the colourcd fluid is diffusible through bladders, &c. Attempts to pre- pare crystallised ferric salicylate did not succeed. C. It. A. W. Observations on the Principle of Maximum Work, and on the Spontaneous Decomposition of Hydrated Barium Dioxide. By M. BERTHELOT (Cowpt. rend., lxxxv, 880).-The following obser- vations illustrate the tendency of chemical systems to assume that par- ticular arrangemcnt which coincides with the evolution of the maximum amount of heat in their furination.Barium dioxide, the subject of these experiments, is stable in the anhydrous state, but decomposes spon- taneously when hydrated :-A specimen of the anhydrous dioxide, prc- pared in January, 1874, contained at that time 9.4 per cent. of oxygen more than required for barium monoxide ; in November, 18177, it con- tained 9.2 per cent. The hydrated dioxide, however, decomposes more easily, especially in presence of excess of water, with formation of the ordinary hydrate, BaO.lOH,O. Some crystallised hydrated barium dioxide contained in January 1874, eight per cent. ayailable oxygen ; some of it was mixed with half its weight of water, and placed in three flasks securely stoppered.In November 1877, the first and third flasks contained only 6.5 per cent. available oxygen, and the second only 6.1 per cent. The formation of crystallised barium hydrate (1% hiekt contains 10H,O) tends to dehydrate the neighbouring portions of hydrated108 ABSTRACTS OF CHENICAL PAPERS. dioxide, and, if excess of water be not present, the anhydrous dioxide thus formed decomposes very slowly. A portion of the same specimen of dioxide, kept for the same length of time under a layer of water, contained only 0.28 per cent. of available oxygen. The thermal phenomena accompanying these reactions are as fol- lows :- The decomposition of anhydrous barium dioxide absorbs heat : Ba02 = BaO + 0 absorbs 6.05, so that this decomposition requires the aid of heat.The transformation of barium dioxide into barium monohydrate and free oxygen disengages heat: Ba02 + H20 = BaH& + 0 evolves 2-76 ki1.-degrees (liquid water) ; + 2.0 (solid water). The same for the higher hydrates : Ba02.7H20 + 3H20 = RaO.lOH,O + 0 gives + 5.3 (liquid water) ; + 3.2 (solid water). Pure hydrated barium dioxide changes more slowly, since each molecule of hydrated barium oxide requires for its formation a cer- tain number of molecules of water from the neighbouring dioxide ; 10(BaOz.,H,O) = 7(Ba0.10H20) f 7 0 + 3Ba02 disengages + 9.5. c. w. w. Influence of Polymerisation on Chemical Compounds. By J. LOWENTHAL (Chern. Centr., 1877, 193).-This theory is intended to explaill why an element is in some cases easily removed from a, com- pound, and in others is not removable without destroying the whole compound ; the cause of isomerism ; why an element, unites with one element in preference to another ; why an element sonietimes combines and sometimes refuses to combine ; and, lastly, reciprocal action, i.e., why LL removes c from b c in some cases, and in others b from ac.The theory supposes the atomicity of elements to depend on the poly- nierisation of the atoms ; this influences also their force of combina- tion, and accounts for allotropic conditions. w. R. Molecular Changes. By H. J. v. JONSTORFF (Chem. Cetztr., 1877, 321).-Small crystals of iodine, after eight years' keeping, had considerably increased in size. Amorphous phosphorus was partially changed into the crystalline variety, after nine yeard keeping.&I* M. P. M. Action of Anhydrous Acids upon Anhydrous Bases. By J. B E c RAMP (Compt. miLd., lxxxv, 799).-Anliydrous lime, projected into anhydrous boric acid in a state of fusion, yields borate of lime, Anhydrous acetic acid acts upon anhydrous lime at 133", forming cal- cium acetate ; the product was dissolved in water and crystallised. The same anhydrous acid combines with anhydrous baryta a t 100". Anhydrous butyric and caproic acids combine with anhydrous lime a t 120" ; the theoretical yield of salt was almost fully realised. Anhy- drous butyric and acetic acids combine with anhydrous ethylic oxide ; the prolonged action of heat is necessary. The same anhydrous acids unite directly with ethylene oxide.These facts raise a question as to the correctness of the term " anhy- dride," now generally appliec! to these bodies by chemists who question their acid character. MI. 31. P. M.GENERAL AND PHYSICAL UEIEMISTRY. 109 Action of Animal Charcoal on Salts. By LEO. L~EBERMANN ( Wiem. Acad. Ber., lxxiv, 331 -344).-Having observed that on filter- ing through animal charcoal a neutral aqueous solution of the barium salt of the acid formed by oxidising glyceriii with dilute chromic acid, the filtrate was strongly acid, and that water filtered through the same charcoal came through quite free from acidity, the author concluded that animal charcoal has the power of decomposing that salt and retaining the basic constituent : similarly barium formate was decom- posed, the filtrate containing free formic acid capable of being distilled off.Somewhat analogous observations as to the retention by animal charcoal of certaiu substances have been made by Heumann, Cheval- lier, Weppen, and also Graham and Hofmann (strychnine), the action being ascribed in some of these instances to calcareous salts, he., present in the charcoal. Tlie author finds that a large number of salts are acted on by animal charcoal, some being wholly retained, and others decomposed, and the base retained to a greater or lesser extent, the action taking place with charcoal freed from earthy matters by treating it with hydrochloric acid and washing with water till the washings were free frorn chloriue. Horn- and blood-charcoal are the most active varieties, bone-charcoal also possessing the power to a large extent ; wood-charcoal and coke are not efficacious in decom- posing salts. To obtain numerical values, the purified charcoal was placed in pieces of combustion-tube 50 c.m.long, plugged at one end with cotton-wool, so as to fill the tube to a depth of 20-30 c.m., and the liquids to be examined were made to percolate through the mass: i n this way the amount of substance contained in the percolate per C.C. could readily be compared with that in the original solution. With barium formate, sodium and lead acetates, calcium glycollate, zinc lactate, ammonium oxalate, and potassium sodium tartrate, the basic constitaents are retailled to a greater extent than the acids, so that the percolates are distinctly acid. Potassium urate, sodium car- bolate and benzoate, calcium benzoate, oxybenzoate, and paroxy-ben- zoate, barium benzoate, acid solutions of sodium sdicylate, and calcium Iiippurate, were wholly retained : apparently the salts were decomposed, as on shaking with ether the charcoal through which calcium benzoate had passed, free benzoic acid was dissolved out.Morpliine acetate is a t first wliolly retained ; but on washing the charcoal subsequently with distilled water, free acetic acid is obtained ; an analogous result is obtained with caffeine citrate. Strychnine nitrate, atropine sulphate, and quinine sulphate formed no free acid ; sodium chloride, nitrate, and sulphate, and potassium chloride, iodide, bromide, cyanide, thio- cyanate, nitrate, and sulphate also were not decomposed, but were partially retained ; whilst sodium borate (alkaline), trisodium phos- phate (strongly alkaline), and disodium-hydrogen phosphate (almost neutral) were decomposed, so that the percolates were a t first neutral and subsequently acid.Calcium chloride arid barium chloride and nitrate were not decomposed, but were retained to a considerable ex- tent ; whilst ferrous sulphate, copper sulphate, and silver nitrate mere largely retained, especially the latter, the percolates being more or less acid : mercuric chloride (acid) passed through neutral, the percolate containing no mercury.110 ABSTRAflTS OF CHEMICAL PAPERS. Solutions of exactly equivalent strength of acetic acid and caustic potash were prepared and made to percolate through the charcoal tubes, as was also a neutral mixture of equal bulks of these two fluids ; in two experiments the quantities of substance retained by the charcoal were: acetic acid, 52 and 70 pcr cent.; potash, 72 and 92 per cent. ; neutral salt, 16 and 23 per cent., these latter amounts consisting of more potash than corresponded with the acetic acid retained, the re- mainder being in the acid filtrate. Analogous results were obtained with copper sulphate solution, about one-fourth of the substance being retained, this amount containing more copper than that corresponding with the sulphuric acid retained. Solutions of lead acetates in absolute alcohol passed through animal charcoal gave percolates containing no free acid ; the author did not succeed in finding any acetic ether in the percolate: an analogous negative result was obtained with sodium acetate and amylic alcohol.[AppFrently, however, fractional distillation only was employed, no mention being made of tests by distilling off the alcoholic liquors and saponifying them by alkalis.] In order to see if aqueous solutions of salts dissociate spontaneously, salt was dissolved in water and the solution distilled in a current of carbon dioxide ; a very faintly acid distillate containing chlorine was obtained. Analogous results were also yielded by barium chloride, no barium being in the distillate (i.e., no spirting having taken place). No galvanic current could be detccted in the charcoal during its action on salts, even with a most sensitive galvanometer. C. R. A. W.101G e n e r a l a n d P h y s i c a l C h e m i s t r y .Existence of Oxygen in the Sun, and a New Theory of theSolar Spectrum.By H. DRAPER (Conzpt. rend., Ixxxv, 613-614).-Uniting all the conditions for obtaining the best results, theauthor photographed simultaneously the spectrum of the sun and thatof oxygen rendered incandescent bF the sparks of a Ruhmkorff coil.The photographs showed that the lines of the oxygen spectrum exactlycoincided in position and relative intensity with certain bright lines inthe solar spectrum, thus proving the existence of oxygen in the sun.The solar spectrum must therefore no longer be mgarded as a con-tinuous spectrum with no other than the absorption lines produced bymetallic vapours ; it must be admitted that it also contains superim-posed lines and bands brighter than the field of the continuous spec-trum.These brighter lines may reveal the existence OP other non-metallic elements, and perhaps some of the so-called dark lines oughtt o be regarded as merely intervals between the brighter lines.R. R.Transverse Absorption of Light. By W. AKEOY D (Chern. i?iTezos,xxxvi, 159).-1n a forrner paper (see this t J o z c ~ m d , i, 1877, 571), theauthor has pointed out the difference between structzcraZ and tramverseabsorption. I n the present paper he describes a new method of obser-vation. The absorbing liquid is placed in a srn:ill glass trough, theends of which are made of thin microscopic glass ; the light passes atright angles to the absorbing medium, and dispersion is eliminated ;the results are quantitative.The yrirLc$e of constancy of absorption islaid down, viz., a coilstarit number of molecules of a substance whensimilarly aggregated produces t h e same amount of transverse absorption.It is shown experimentally that a solution of potassium dichroniategives the same amount of absorption as a plate of the solid itself con-taining the same amount of dichrome as was contained in the solution.The size of the particles producing isolated absorption-bands is approxi-mately determined for a few substances. The following numbers aregiven :-Incipient Width of molecularabsorption. aggregate in mm.Potassium permanganate. ... 3 bands 80Methylaiiiline violet ........ 1 band 63Magenta.................. 1 ,, 47Iodine green 1 9 9 .............. 480The smaller the size of the particles in a given thickness of solid,the more readily do short wave radiations appear to be absorbed.M. 31. P, M.Conductivity of Electrolytes. By A. F. BE RGGBEN ( A ~ T L . Chi.,%.Plys. [ 21, i, 4C3!)-.510) .-‘l’he author used Pallzow’s method, describedin the BerZin Jfoientsbericht (1868, p. 486). He found, however, th;atVOL. XXXIII. 102 ABSTRACTS OF CHEMICAL PAPERS.this method was applicable only to such fluids as did not react withthe amalgamated zinc plates. After explaining in considerable detailthe method employed, the author gives his results in ;I tabular form,the substances with which he experimented being normal and acidpotassium sulphates, normal sodium sulphate, magnesium sulphate,normal ammonium sulphate, and sodium chloride. The results ofthese experiments are represented graphically in plate iii, fig.4 of thevolume.The condiictivity appears continuously either to increase or diminishwith an increasing concentration of the solution in the different cases.I n the case of potassium sulphate the conductivity appears: to increase.Kohlrausch and Grotrian have found that in the case of potassiumchloride, the relation between the conductivity and the percentage ofsalt in solution may be expressed by a straight line. The conductivityof sodium sulphate seems t o increase less rapidily with an increased per-centage of salt in solution than in the case of potassium sulphate.Inammonium sulphate the conductivity also increases with the balt per-centage, but appears to approach a maximum, as with a furtherincrease in density of the solution no further increase in conductivitycan be observed.The solution of magnesium sulphato which proves the hest con-ductor contains about 16 per cent. of salt, and thc conductivity wasmeasured a t about 8" C. Acid potassium sulphate did not yield suchregular results as the other salts. This the author conjectures may bedue to impurities. It is, however, a better conductor than the normalsalt.According to their conductivity, the sulphates may be arranged inthe following order :--(NH&SO,, KIISO4, K2S04, Na2S04, andMgS04. Kohlrausch and Grot'rian have found the following order inthe conductivity of the chlorides of the alkaline earths and alkalis:-(NH,)Cl, KC1, NaCI, LiCl, CaCl,, SrCl,, CaCI,, and MgC1,.Certainanalogies, therefore, would appear to exist between the chlorides justmentioned and their corresponding sulphates.Among these salts, the solutions of which have a relatively highconductivity the ammonium salts rank highest. Kohlrausch andGrotrian foand a solution of ammonium chloride, the conductivity ofwhich was almost half that of the best acid conductors. Wiedemannalso has found that ammonium nitrate has a very high conductivity.The author's experiments show that ammonium sulp'hate has a con-ductivity considerably higher than that of any of the other sulphatesinvestigated.The following table contains some determinations of the conductivityof solutions of potassium, sodium, ammonium, and magnesium chlo-rides compared with that of their corresponding sulphates in solution,the former being taken from Kohlrausch and Grotrian :GENERAL AND PHYSICAL CHEMISTRY.103Per cent.555101520510-t. Substance.KC1 ...........NaCl ..........NH4Cl. ........ ...................... ...........MgClz ........ ...........10SL.520486696136519802547503827Substance.R2S04 .........Na2S04 ........(NH4)&304 ..... . . . . . . . . . . . . . .9 9 .....MgS04 ........10SL.33527838473210361244186282From this it may be easily seen that the alkaline. chlorides possess ahigher conductivity than the corresponding sulphates.5. M. T.Determination of the Electric Conductivity of certainLiquids with a Constant Current. By J. TOLLINGER (Ann.Chenz. Phys. [S], ii, 510--516).-The object of the author in theseexperiments has been, not so much to reinvestigate the conductivity ofliquids already determined, as to test by constant currents the valuesfound by Kohlrausch and Grotrian with varying currents.As difficnlt8ies and objections have been found to t,he use of troughsand strsight glass tubes in the experiments, the author employs aU-tube, and to obtain a more constant polarisation he uses as elec-trodes spirals of platinum wire, which have t'he further advantage ofallowing any gas generated t o escape readily. The column of liquidto be tested was introduced, together with a rheostat, into one branchof a Wheatstone's bridge, whilst a similar tube with equal electrodesfilled with the same liquid, as well as a rheostat, was placed in theother hranch, in order to eliminate small changes in polarisation dueto changes of temperature and irregularities of the currents.Thewhole arrangement is shown in plate iv, fig. 1, of the volume.During the experiment the electrodes of the second tube, as well asthe resistance selected, remain constant, while in the other branch ofthe bridge the electrodes are lengthened and shortened. To preservea constant, temperature, a large water-bath was used, into which thewhole apparatus was placed. With the exception of sulphuric acid,the liquids investigated by Kohlrausch were employed.In the fol-lowing table, so far as possible, Kohlrausch's results are comparedwith those of the author. Any differences between them may possiblybe explained hy slight differences in the nature of the liyuids, arisingfrom impurities.z' 104 ABSTRACTS OF CHEMICAL PAPERS.1.83641.82861 .77871 *22081 *18451 -28111.16811 -0721 *34831 '0131 -18621 '091211'7.5 94 '5 0 '150(18 -3 92 '5 0 '150(18 .I 84 '6 0 *150(17 -9 50 '0 0 -3OOi18 -2 17 *0 0.149118 -2 23 '1 0 *149(18.4 15 '1 0 '149117.1 10 -0 0 -299118.1 34 -0 0 *299(17 -3 2 -5 0 *149(17.9 29 -7 0 *299(18 -0 18 '3 0 '299(I&SOJ77¶?Mg;O4ZnSO,KHSOLiCl .HNO,HC1..cuso,KzC03107'299 -22120 -8728 *96217 *08213 -30245 '00140 *3596.99255 *4'727 -9628-87l 3 I 4 l 516'53 94317.52 101815.30 83618 -33 697818 -14 46118 *74 47119 '08 41018.30 144017.55 207818.80 39316 -48 720616 -17 69'796 7 8 9 10 11 12cy I 0; I Conductivity k.18"98310339276941461462400143621 0038673627182Tollingcr..... ..4574603961434208638373177144398010309156912451452 ....212173307174+ 0 - 3+ 0.3+ 1 ' 3 + 0.4+ 0.9 + 0.5+ 1.0+ 0.1 + 0.7+ 0.8 + 0.6+ 0 - 5IFrom these results it mag be seen that the values found with con-stant and with induction currents do not differ materially.J. M. T.Specific Inductive Capacity. By V. NEPRENEUF (Compt. Tend.,lxxxv, 547).-!I!he author's experiments relate t o the energy of thesparks which pass between the plaOes of a condenser when dielectricsof different kinds and thicknesses are interposed.The results confirmthe established laws of electric induction. R. R.Thermoelectric Temperature Determinations. By R o SE N-THAT^ and MOLLER (Chem. Centr., 1877, 241).-The authors haveapplied a thermopile of copper and iron to the determination of groundtemperatures for hygienic purposes.Specific Heat of Water according to the Investigations ofW. Wunchhausen. By A. WULLNER (Am. Chem. Php. ['L], ii,592-605) .-The author alludes fully to experiments by Pfaundler andPlatter, Hirn, Jsmin and Amaury, Hess and Person, which do notquite agree with those of Regnault as to the equation for the specificheat of water between 0" and 100".These differences between thevarious experimenters have led the author t o institute a new series ofinvestigations, the experimental part of which has been carried out byMunchhausen. A full description of the method employed and tablesof the results found are given.The author regrets that Munchhausen was not able to continue hisexperiments between 70" and loo", but says that the cxperirnentsbetween 1 7 and 70" suffice to indicate the direction taken by thespecific heat between the latter temperatures.M. M. P. MGENERAL AND PHYSICAL CHEMISTRY. 105Calculated.From the numbers obtained, the author deduces the following for-mula for the specific heat at t.Ic = 1 + 0.00030192 t.A calculation of the observations with this value for the constant,gives the mean error of experiment as *0016 ; therefore, the probableerror of ,00108.For comparison of the observations and calculations,Series I1 and VI are given.Observed.Series 11.A+ 17t 3- 27+ 5 - 10 - 20 + 13+ 8- 3- 9 + 15Series TI.Calculated. Observed. A- 13+ 7+ 8t 4- 23 - 214- 31 - 11From these it may be seen that the differences are of the same orderin both series, so that the equation fully represents the results of expe-riment. The uncertainty of the value of the coefficient of temperatureas given by the probable error is 0.0000099 ; so t!hat the specific heatat t lies betweenk = 1 + 0.0002920 t andIG = 1 + 0*0003118 t.The author then does away with the objection that a perceptible lossof heat might be caused by the passage of the water added to thecalorimeter, through the air, his arguments being based on the expe-riments of Dulong on the rate of cooling of water in air.The author concludes that between 0 and 70", or if it be permittedto go beyond actual experiment, between 0 and 100" also, the resultsobtained show that the specific heat increases more rapidly than Reg-nault's numbers, but much more slowly than those of Jainin andAmaury ; thus, k , according to the several experimenters, is as follows :-At 20" ......1.0060 1-0012 1.0235,, 40 ...... 1.0121 1.0030 1.0459 ,, 60 ...... 1.0181 1.0056 1 * 0 70 3,, 80 ...... 1.0241 1.0089 1.0957,, 100 ...... 1,0302 1.0130 1.1 220Wiillner.Regnault. Jamin.According to the equation used by Jnmin and Amaury, the increasein the specific heat would be about €ourfold, and in the case of Xeg-nault's, little less than one-half that found by the author at 100".J. If. T106 ABSTRACTS OF CHEMICAL PAPERS.Note by the Abstractor.-It is difficult to give an adequate idea ofthe author's argument without a translation of the first part of hispaper and the tables in extenso, which would be beyond the limits ofthis Journal.Apparatus for Measuring the Heat of Vaporisation ofLiquids. By M. B E R T HE L o T (Compt. mad., lxxxv, 646-648).-The liquid is distilled from a, flask-shaped glass vessel, the neck ofwhich is, however, sealed a t the top, and near to this internally is theopen extremity of a glass tube, which traverses the centre of thevessel, passing out through the bottjom.This tube is continueddownwards from the bottom of the vessel for a short distance, and itslower extremity is adapted to a worm-tube wholly immerscd in thewater of the calorimeter. The apparatus is figured in the paper,which also describes the mode of operating.Bp M. BERTHELOT(Con@ rend., Ixxxv, 648--651).-1n this paper the author showsthe influence which differences in the physical states of a body mayhave in determinations of its heat of fusion. The states referred toare not isomeric modifications of the substances, but change, likethose induced by the variable plasticity of resinous bodies. Verydifferent values are obtained for hhe heat of fusion of chloral hydratewhen the sample has been recently melted and then solidified, sincethis substance will even for days continue to retain some portion of itsheat of fusion, and several months will be required for its return to stdeterminate thermal condition. R.R.Specific Heat and Latent Heat of Fusion of Platinum. ByJ. V I O L L E (Compt. rend., lxxxv, 543-546).-The paper describes themethod adopted by the author for determinations of the spccific heatof platinum at high temperatures. The results lead to the followingformula for the mean specific heat of platinum between 0" and to:-Cz = 0.0317 + 0*000006t, the superior limit being 1200". Betweenthe same limits the true specific heat a t to is represented by yt = 0.317 +0.000012t.Assuming these formulae to represent the specific heat ofplatinum up to the melting point, the author applies them to the ex-perimental results obtained with the fused metal, and arrives a t 1779"as the melting point of platinum, and 27.18 as its latent) heat of fusion.The data which are supplied by the author's experiments permit pla-tinum to be used in determinations of high-temperature melting pointsand speci6c heats of other substances. He has in this way obtained954" as the melting point of pure silver.Contributions to Chemical Statics, By ERNST B R ~ C K E(Wierz. Akad. Bey., lxxv, 507--2;?2).-The author has studied the in-fluence of temperature, dilution, addition of acids, and condition ofmolecular aggregation on the coloured solution produced by addingsalicylic acid to ferric chloride. The violet tint of iron salicylate isdeveloped only in slightly acid solutions ; on cautiously neutralizing, aBurgundy wine tint is first developed, and then the solution becomesyellow or colourless.On boiling a solution prepared by adding sali-R. R.Determination of the Heat of Fusion.R. ItGENERAL AND PHYSICAL CHEMISTRY. 107cylic acid to ferric chloride until no alteration is produced by addingto the coloured liquid either a little ferric chloride or a little salicylicacid, the tint disappears to a greater or lesser extent, but is reproducedslowly on cooling and standing, so that after some days the colour isthe same as before heating. Analogous results are obtained if thecoloured liquid be acidified with small quantities of hydrochloric, phos-phoric, or sulphuric acid before heating ; the acid causes in the colda greater or less lightening in tint according to the quantity added,complete decoloration ensuing after a certain amount is added.Adark-coloured solution, which has been partially lightened by additionof acid, is much less bleached on dilution with water than one of thesame tint, but not containing acid; whilst a soliltion to which justenough acid has been added to destroy all the violet tint is rendereddistinctly violet on adding distilled water. It is possiblc to use ferricsalicylate as an indicator in titrnting sulphuric, nitric, and hydro-chloric acids, but it does not answer with organic acids such as oxalic,tartaric, acetic, &c.These acids act differently from the mineralacids so far as modifying the colour is concerned; thus, little or noeffect is produced on heating a solution lightened in tint by oxnlic acid,and but little violet is produced on diluting a solution just bleachedby oxalic acid. Citric, tartaric, and acetic and succinic acids producethe same result as hydrochloric acid on heating ( i e . , the solution is moreor less decolorised, the tint reappearing on cooling). A much largerqnantity of acetic acid is, however, requisite then of hydrochloric acid,and so on with the others. Formic acid acts as oxalic acid, and notits acetic.The colouring matter of ferric salicylate is not suspended solidmatter ; no settling takes place even on long standing ; moreover.thecolourcd fluid is diffusible through bladders, &c. Attempts to pre-pare crystallised ferric salicylate did not succeed. C. It. A. W.Observations on the Principle of Maximum Work, and onthe Spontaneous Decomposition of Hydrated Barium Dioxide.By M. BERTHELOT (Cowpt. rend., lxxxv, 880).-The following obser-vations illustrate the tendency of chemical systems to assume that par-ticular arrangemcnt which coincides with the evolution of the maximumamount of heat in their furination. Barium dioxide, the subject of theseexperiments, is stable in the anhydrous state, but decomposes spon-taneously when hydrated :-A specimen of the anhydrous dioxide, prc-pared in January, 1874, contained at that time 9.4 per cent.of oxygenmore than required for barium monoxide ; in November, 18177, it con-tained 9.2 per cent.The hydrated dioxide, however, decomposes more easily, especiallyin presence of excess of water, with formation of the ordinary hydrate,BaO.lOH,O. Some crystallised hydrated barium dioxide contained inJanuary 1874, eight per cent. ayailable oxygen ; some of it was mixedwith half its weight of water, and placed in three flasks securelystoppered. In November 1877, the first and third flasks containedonly 6.5 per cent. available oxygen, and the second only 6.1 per cent.The formation of crystallised barium hydrate (1% hiekt contains10H,O) tends to dehydrate the neighbouring portions of hydrate108 ABSTRACTS OF CHENICAL PAPERS.dioxide, and, if excess of water be not present, the anhydrous dioxidethus formed decomposes very slowly.A portion of the same specimenof dioxide, kept for the same length of time under a layer of water,contained only 0.28 per cent. of available oxygen.The thermal phenomena accompanying these reactions are as fol-lows :-The decomposition of anhydrous barium dioxide absorbs heat :Ba02 = BaO + 0 absorbs 6.05, so that this decomposition requiresthe aid of heat. The transformation of barium dioxide into bariummonohydrate and free oxygen disengages heat: Ba02 + H20 =BaH& + 0 evolves 2-76 ki1.-degrees (liquid water) ; + 2.0 (solidwater). The same for the higher hydrates : Ba02.7H20 + 3H20 =RaO.lOH,O + 0 gives + 5.3 (liquid water) ; + 3.2 (solid water).Pure hydrated barium dioxide changes more slowly, since eachmolecule of hydrated barium oxide requires for its formation a cer-tain number of molecules of water from the neighbouring dioxide ;10(BaOz.,H,O) = 7(Ba0.10H20) f 7 0 + 3Ba02 disengages + 9.5.c. w. w.Influence of Polymerisation on Chemical Compounds. ByJ. LOWENTHAL (Chern. Centr., 1877, 193).-This theory is intended toexplaill why an element is in some cases easily removed from a, com-pound, and in others is not removable without destroying the wholecompound ; the cause of isomerism ; why an element, unites with oneelement in preference to another ; why an element sonietimes combinesand sometimes refuses to combine ; and, lastly, reciprocal action, i.e.,why LL removes c from b c in some cases, and in others b from ac.Thetheory supposes the atomicity of elements to depend on the poly-nierisation of the atoms ; this influences also their force of combina-tion, and accounts for allotropic conditions. w. R.Molecular Changes. By H. J. v. JONSTORFF (Chem. Cetztr.,1877, 321).-Small crystals of iodine, after eight years' keeping, hadconsiderably increased in size. Amorphous phosphorus was partiallychanged into the crystalline variety, after nine yeard keeping.&I* M. P. M.Action of Anhydrous Acids upon Anhydrous Bases. ByJ. B E c RAMP (Compt. miLd., lxxxv, 799).-Anliydrous lime, projectedinto anhydrous boric acid in a state of fusion, yields borate of lime,Anhydrous acetic acid acts upon anhydrous lime at 133", forming cal-cium acetate ; the product was dissolved in water and crystallised.The same anhydrous acid combines with anhydrous baryta a t 100".Anhydrous butyric and caproic acids combine with anhydrous lime a t120" ; the theoretical yield of salt was almost fully realised.Anhy-drous butyric and acetic acids combine with anhydrous ethylicoxide ; the prolonged action of heat is necessary.The same anhydrous acids unite directly with ethylene oxide.These facts raise a question as to the correctness of the term " anhy-dride," now generally appliec! to these bodies by chemists who questiontheir acid character. MI. 31. P. MGENERAL AND PHYSICAL UEIEMISTRY. 109Action of Animal Charcoal on Salts. By LEO. L~EBERMANN( Wiem. Acad. Ber., lxxiv, 331 -344).-Having observed that on filter-ing through animal charcoal a neutral aqueous solution of the bariumsalt of the acid formed by oxidising glyceriii with dilute chromic acid,the filtrate was strongly acid, and that water filtered through the samecharcoal came through quite free from acidity, the author concludedthat animal charcoal has the power of decomposing that salt andretaining the basic constituent : similarly barium formate was decom-posed, the filtrate containing free formic acid capable of being distilledoff.Somewhat analogous observations as to the retention by animalcharcoal of certaiu substances have been made by Heumann, Cheval-lier, Weppen, and also Graham and Hofmann (strychnine), theaction being ascribed in some of these instances to calcareous salts, he.,present in the charcoal.Tlie author finds that a large number of saltsare acted on by animal charcoal, some being wholly retained, andothers decomposed, and the base retained to a greater or lesser extent,the action taking place with charcoal freed from earthy matters bytreating it with hydrochloric acid and washing with water till thewashings were free frorn chloriue. Horn- and blood-charcoal are themost active varieties, bone-charcoal also possessing the power to alarge extent ; wood-charcoal and coke are not efficacious in decom-posing salts. To obtain numerical values, the purified charcoal wasplaced in pieces of combustion-tube 50 c.m. long, plugged at one endwith cotton-wool, so as to fill the tube to a depth of 20-30 c.m., andthe liquids to be examined were made to percolate through the mass:i n this way the amount of substance contained in the percolate per C.C.could readily be compared with that in the original solution.With barium formate, sodium and lead acetates, calcium glycollate,zinc lactate, ammonium oxalate, and potassium sodium tartrate, thebasic constitaents are retailled to a greater extent than the acids, sothat the percolates are distinctly acid.Potassium urate, sodium car-bolate and benzoate, calcium benzoate, oxybenzoate, and paroxy-ben-zoate, barium benzoate, acid solutions of sodium sdicylate, and calciumIiippurate, were wholly retained : apparently the salts were decomposed,as on shaking with ether the charcoal through which calcium benzoatehad passed, free benzoic acid was dissolved out.Morpliine acetate isa t first wliolly retained ; but on washing the charcoal subsequentlywith distilled water, free acetic acid is obtained ; an analogous resultis obtained with caffeine citrate. Strychnine nitrate, atropine sulphate,and quinine sulphate formed no free acid ; sodium chloride, nitrate,and sulphate, and potassium chloride, iodide, bromide, cyanide, thio-cyanate, nitrate, and sulphate also were not decomposed, but werepartially retained ; whilst sodium borate (alkaline), trisodium phos-phate (strongly alkaline), and disodium-hydrogen phosphate (almostneutral) were decomposed, so that the percolates were a t first neutraland subsequently acid. Calcium chloride arid barium chloride andnitrate were not decomposed, but were retained to a considerable ex-tent ; whilst ferrous sulphate, copper sulphate, and silver nitrate merelargely retained, especially the latter, the percolates being more or lessacid : mercuric chloride (acid) passed through neutral, the percolatecontaining no mercury110 ABSTRAflTS OF CHEMICAL PAPERS.Solutions of exactly equivalent strength of acetic acid and causticpotash were prepared and made to percolate through the charcoaltubes, as was also a neutral mixture of equal bulks of these two fluids ;in two experiments the quantities of substance retained by the charcoalwere: acetic acid, 52 and 70 pcr cent. ; potash, 72 and 92 per cent. ;neutral salt, 16 and 23 per cent., these latter amounts consisting ofmore potash than corresponded with the acetic acid retained, the re-mainder being in the acid filtrate. Analogous results were obtainedwith copper sulphate solution, about one-fourth of the substance beingretained, this amount containing more copper than that correspondingwith the sulphuric acid retained.Solutions of lead acetates in absolute alcohol passed through animalcharcoal gave percolates containing no free acid ; the author did notsucceed in finding any acetic ether in the percolate: an analogousnegative result was obtained with sodium acetate and amylic alcohol.[AppFrently, however, fractional distillation only was employed, nomention being made of tests by distilling off the alcoholic liquors andsaponifying them by alkalis.]In order to see if aqueous solutions of salts dissociate spontaneously,salt was dissolved in water and the solution distilled in a current ofcarbon dioxide ; a very faintly acid distillate containing chlorine wasobtained. Analogous results were also yielded by barium chloride, nobarium being in the distillate (i.e., no spirting having taken place).No galvanic current could be detccted in the charcoal during itsaction on salts, even with a most sensitive galvanometer.C. R. A. W