INORGANIC CHEMISTRY. 89 I n o r g a n i c Chemistry. Allotropie Modifications of Hydrogen, By J. THOXPEN (BeT-., 12, 203O).-The author points out that ‘l’ominasi’s statement (Acr~tl. Illi’lun), that the heat of fcrmation of potassium chlorate is 9,760, and that of potassiuni chloride 104,476 units, and consequently 104,476 - 9,760, i.e., 94,716 heat-units, are alisorl~ecl in the conversion of potassium chlorate into chloride, contains no less than three errors. The heat of formation of potassium clilorate is 95,840, and not 9,760, the latter number representing the lieat evolved in the convcrsion of potassium chlorate into chloride in the dry way. Instead of 94,716 heat-units being sbsosbod in the reduction of the chlorate to the chlo- ride, a liberation of 15,370 heat-units takes place.It is obvious that the theoretical speculations based on these incorrect data are valueless. A New Method for Prepaxing Hydriodic and Hydrobromic Acids. By G. BRUYLAN‘TS (Be?.., 12, 2Wl-2062) .-Hjdriodic acid can be easily prepared by heating a solution of iodine (2u grams) in copaiba oil (60 grams) in a retort connected with an upright condenser. The gas is purified by passing it through a drying tube. When the evolution of gas slackens, fresh iodine is brought into the retort, and the process is continued until about 1.50 grams of iodine have been used. In the preparation of hydrobromic acid by this method, the bromine must be slowly dropped into the retort containing the oil, and the gas should be purified by passing through three drying towers.w. c. w. w. c. w.90 ABSTRACTS OF CHEMICAL PAPERS. Influence of Volume and Temperature in the Preparation of Ozone. A New Ozoniser.-By A. R .LEEDS (A~WUZA~L, 198, 30- 42) .-A solution of potassium dicbromate (not necessarily saturated) mixed with sulphuric acid is placed in a suitable vessel, within which a bell-jar can be placed, and pieces of phosphorus are partly immersed in the liquid. It is better, however, to connect three such jars and draw the air through them by means of an aspirator. For this purpose, the necks of the jars are cernented into brass caps, which are screwed to it bar capable of being raised and lowered as in a gnlvanic battery ; the stoppers are replaced by corks covered with paraffin, through each of which pass three glass tubes, one ending just below the stopper, another just above the liquid, and the third bent into a horizontal ring at the end.The first two tubes are connected so as to allow a current of air to be drawn through the apparatus ; the third is for lowering or mising the phosphorus. The pieces of phosphorus are melted .in watch-gla$ses to give them w more convenient shape, and are placed on glass plates in glass cells in the liquid. A flexible tube for con- veying the ozone from the generators was made of “ cei-ite” (“ kerite-” schlauch), and found to answer rery well. The maximum amonnt of ozone obtained was a little over 2.5 mgrms. per litre of air ; but a s the generator may be connected with the aspirator and allowed to work for any length of time, the s~ipply is unlimited.A Possible Cause of Variation of the Proportion of Oxygen in the Air. BF E. W. ~\~ORT,EY (Chew. News, 40, 184-186, and 1 !49-20l).-Looniis has proposed the theory that certain great and siidden depressions in the temperature of the atmosphere are caused hy the velatical descent of currents of air from cold elevated regions. If such is the case, then the air at the surface of the earthduring such depressions may contain a smaller amount of oxygen than the a;c-erage. Jolly concludes from his experiments that the air a t the equator is poorer in oxygen than that a t tjEie polar regions, owing to the amount of oxygen consumed in oxidation being greater than that liberated by reduction. Facts, however, do not confirm these conclusions, no dif- ference in the composition of the atrnosplicre of the two regions having hithertc been detected.According to the author’s views, based on Loomis’ theory, air col- lected at the centre of an area covered by a descending current would, a t a given moment, be a sample fresh from the upper atmosphere; whilst a sample collected on one side of this centre would consist of a mixture of s w f m e and wpper air, but still containing a deficiency of oxygen. Although the author has not yet succeeded in making these experiments, he has, while laying plans for the ~ o r k , conducted espe- yiments on ordinary air, to ascertain what light can be thrown 011 the changes in composition of the atmosphere. The apparatus used was constructed on McLeod’s modification of Frankland and Ward’s appa- ratus, with important modifications, so as to reduce all causes of error to a minimum.The samples were collected in the open country, in glass vessels. and preserved over mercury freed from carbonic anhydride, and exploclcvl A temperature of 24” gives the best results. G. T. A.INORGANIC CHEMISTRY. 9J with pure hydrogen. Some samples were collected in stoppered and c;ipped bottles, which were inverted, and the caps filled with water. Analyses of air were made daily from 28th December, 1878, to Gtlh April, 1879, during ivhich period some very marked and sudden de- pressions of temperature occurred, which were accompanied by a decrease in the quantity of oxygen. The deficiency, however, as might have been expected, was not proportional to the decrease i n tempe- rature (see also p.85 of this volume). By G. WOLFRBX (AmnZe/r, 198, 95--98).-IGimmerer ( J . pi.. Chem., 90, 190) has desribed a method according to which perbroinic acid may be obtained br the action of d ~ y bromine on clry perchloric acid, the latter being prepared i\ t the tlime by the decomposition of potassium perclilorate by sulphuric acid. The author has repcated this experiment, and finds tliat the :icid thus obtained, corresponding in all respects with that described hy Kammerer, is nothing more than a mixture of percliloric and sulphuric acids. The apparent absorption of the bromine by tlie perchloric acid is explained by the fact that perchloric acid, when heated with an excess of sulphuric acid, is decomposed into oxygen mid chlorine, and it is this latter which takes u p tlie bromine i n the above experiment, forming bromide of chlorine : this is volatilised, together with the excess of bromine, during the subsequent concen- tration of the liquid. L.T. 0's. Preparation of Perbromic Acid. T. C. Researches on Nitrous Acid and Nitrogen Tetroxide. By G. LUNGE (Dingl. yoZyt. J., 233, 155-165; cornp. this Journal, Abst., 18'79, 770).-8econd Pa7-t.- Oti the Re7at;ow of the Acids OJ hTitrogetl to ,Sulplm-ic ileitZ.-Our knowledge of this relation is not by any weans complete. It is well known that nitrous acid, either in the liqnicl or gaseous form, o r jmduced nascent from the union of nitrogen dioxide with oxygen, is clissolved by sulphuric acid of about. 1.7 sp. gr. ; but the heliaviour of nitrogen tetroxide towards snlphuric acid is not accu- rately known.The author has shown that it is dissolved by sulpliuric i~cid, forming nitrosulphuric and nitric acids ; but according to Weber and Winkler, nitlogen tetroxide is dissolved as such by sulphuric acid of 66" B., producing a reddish-yellow solution, which, when heated, gives off nitrogen tetroxicle with violcrit ebullition, and leaves a liquid Iiaviug the properties of nitrosulphuric acid. Winklcr stated that 28 072 grams of sulphuric acid a t 60"B. absorbed 7.307 grams of nitrogen tetroxide, but that on heating gently, the latter was eiitirely expelled. Weber describes the effects of nitrogen tetroxide on sulphui*ic acid of different specific gravities, but only qualitativel~ : thns, sulphuric acid at, a sp. gr. of 1.7 absorbs nitrogen tetroxide without becoming coloured: liecce i t was assunied that the latter was decomposed; a t a sp.gr. of 1.55 the sulphuric acid becomes yellow, and hence it was supposed that the greater part of the nitrogen tetroxide was simply dissolved. Acid of 1-49 sp. gr. takes a greenish-yellow colour; acid of 1.41 sp. gr. takes an intense green d o u r ; acid of 1.31 sp. gr. becomes blue and liberates nitrogen dioxicle, which escapes with violent ebullitioii on gently heating. The p e l 192 ABSTRACTS OF CHEMICAL PAPERS. and blue colours were supposed to be due to the formation of nitrous wid, the nitrogen tetroxide having been decomposed into that sub- stance and nitrogen dioxide. As these results are very important to vitriol manufacturers, the author studied them more accurately, and, its far as possible, quantitatively.The nitrogen tetroside, prepared from d r g fused lead nitrate, was measured oif from a burette, and mixed with pure sulphuric acid, which had been diluted to different strengths with water, and the effects of heat upon these mixtures were also noted. The following are given as examples of the mctliod employed and of the results obtained by the author in carrying out the expel-iments :- 100 C.C. sulphuric acid of 1-84 sp. gr., t o which was added 2 C.C. = 3 grams liquid nitrogen tetroxide, gave a colourless solution with :L very feeble odour, recaJling that of ozone. The amount of nitrogen dioxide evolved from 1 C.C. of this solution in the nitro- meter was determined, and also the amount required to decolorise 10 C.C.seniinormal potassium permangmate solution. From the results, the author calculates that his nitrogen tetroxide contained of pure nitrogen tttroxide 93 per cent., and of nitric acid 7 per cent. ; but lie argues, as in reality the nitrogen tetroxide does not exist, as such in the sulpliuric acid, but has undergone a decomposition, one part of tlie tetroxide having been converted into nitric acid a t the expense of the oxjgen of the other part, whilst the part which has been robbed of its oxygen remains as nitrous acid in combinatlion with tlie sul- phuric acid; then assuming that this lower oxide takes the oxygen from, and decolorises the potassium permanganate, this would wive 46.5 per cent. as nitrous acid, and 53.5 per cent. as nitric acid.?'he other calculations are niade on this supposition, that is, it8 is first assumed that all the nitrogen tetroxide remains as such, and the defi- ciency in the theoretical amount of oxygen required is calculated as nitric acid; but if, on the contrary, tho amount of oxygen required be less than that found by the permangnnate process, then he assumes that no nitric acid is present, but that nitrous acid must have been originally present as an impurity. (I.) The acid was heated to 2tiUo, and kept at that temperature for one hour ; any free nitrogen tetroside, if it were present, must have been thus expelled. When the ttmperature rose t o 20Uo, R little red vspour was evolved, and the liquid acquired a golden-yellow colour ; b u t on cooling, it again became colourless.On analysis the author calculated that 77.9 per cent. of the nitrogen present existed as N,O,, and 21.1 per cent. as HNO,; there is, con- sequently, he si;tys, a large amount of the nitric acid driven off and anobher part changed into nitrous acid. (11.) On continuing t o heat for one hour longer, a further change took place of the bame kind, and 94..5 per cent. of the nitrogen re- maining existed as Nz03, in combiliation with the sulphuric acid jorming nitrosulphnric acid ; whilst 5.rj per cent. remained as HNO;;, n~ld 18 per cent. of the nitrogen originally present having been ex- pelled by the heating. (111.) Another experiment was made by adding pure nitric t o pu:.eTN ORGANIC CHEMISTRY. 93 sulphuric acid, and analysing the resulting mixture, but no change was found to have taken place.(1V.) On boiling the mixture for half-an-hour, however, red fumes were given off, and the whole of the nitrogen present was converted into nitrous acid, which was found in combination with the sulphuric acid. That nitric acid is thus broken up has also been demonstrated in another way by Winkler, who collected the oxygen which was evolved from the decomposition. The author did not find the same result as Winkler with sulphuric acid of 66OB. above mentioned, and he explains this by assuming that, Winkler employed so much nitrogen tetroxide that it left it hrgt. excess beFond that which could combine with the sulphuric acid as nitrous acid : hence the sudden and violent ebullition and liberation of nitrogen tetroxide on heating the mixtuye.2 C.C. nitrogen tetroxide added to sulphuric acid of 1.805 sp. gr. was hroken up into practically the same proportions of nitrous and nitric acids as in the first experiment, with acid of 1.54 sp. gr. Other experiments are described in which sulphuric acid of 1.75 sp. gr. was mixed with nitrogen tetroxide and then heated ( a ) , so that the vapour evolved might a t once escape, and ( b ) where a long tube was attached to the flask in which the mixture was heated, so that the vayoar might condense and flow back again to the acid in the flask. In ( a ) nitrous acid, but no nitric acid mas found, whilst in ( b ) nitric acid was present but no nitrous acid ; this is explained by the fact, that it requires concentrated sulphuric acid to combine with and retain the nitrous acid ; and in ( a ) the acid became concentrated by evaporation, whilst in ( b ) it remained of about the same sti.eugth, arid was unable to retain the nitrous acid.Again, when the mixture was heated on a water-bath a t about 95", no such changes occurred. As Winkler found, that on heating his mixture of acid of 60°B. with nitrggen tetroxide, the latter was evolved, he presumed that i t existed as a mechanical mixture with the acid. This the author denies, stating that had Winkler examined the acid a,fter boiling, he would have found that it contained nitric acid, and that the nitrogen tetroxide had really undergone decomposition ; and further, that ho must have heated it considerably above the temperature of boiling water, otherwise no change would have resulted, and no red fumes would have been liberated.When the amount of nitrogen tetroxirle added is in excess of that required to form nitrnsulphuric acid, the author is uncertain from analysis whether it exists in the acid in the form of nitrous acid or of nitrogen tetroxide. W. T. Norwegium. By T. DAHLL (Rer., 12, 15'3 1-1 732) .-The prepam- tion of this metal from the ore has already been described (this Journal, Abs., 1879, 890). It melts a t 254', and its atomic weight is 145.552 (RO), or 218.928 (TC2G3). It can be separated from bismuth, which it closely resembles, by the solubility of its oxide in alkalis and a1 kaline carbonates. w. c. w.94 ABSTRACTS OF CHEMICAL PAPERS. Constitution of Antirnonic Acid. By P. CONRAD (C'henz.News, 40, 197--198).-With a view t o decide the constitution of antimonic wid, specimens of it were prepared from the pure metal by seven different methods, and carefully analysed. The antimony was determined as snlphide, with the usual precau- tions, whilst the water mas determined, tint by exposure over sulphu- yic acid, and iheii by heating in a slow stream of nitrogen, and collecting the wder in a weighed calcium chloride tube. The sub- stance was weighed after heating, and any discrepancy between the loss of weight by the substance and the water expelled, was regarded as due to the reduction of the oxide. The loss of water takes place verg gradually. The acid dried over sulphnric acid a t the ordinary temperature has the constitution Sb,05.3H,0, whereas the acid dried in a current of dry air a t the ordinary temperature is represcnted by SbL0,..5H,0.At loo", this loses 3 mols. H20, Sb,05.H,0 being formed ; and between 100" and 200" one more mol. H,O is expelled, leaving Sb,0,.H20. Contrary to the statement of Daubrawa (Amrden, 186, l l O ) , the anhydrous pentoxide is not formed at 2 i 5 " , and even a t 300" the pro- duct still contains + a mol. H,O. This is driven off only a t a, red heat when the oxide begins to decompose. There seems to be reason t o believe in the existence of three anti- moriic acids, corresponding with three acids of pliosphorus- Orthonntimonic acid, H3Sb04 = 3H,0.Sb205. Pyroantimonic acid (nietaritimonic acid, Fremy) H4Sb,O7 = Meta-antimonic acid (antimonic acid, Fremy) HSbO, = 2HzO.Sb205.H20.SbZOj. The gradual formation by heat of the second and third acids from the first is similar to the formation of the corresponding acids of phos- ph oras. L. T. 07s. Salts of Plumbic Acid. By 0. SEIDET, ( J . pr. C h L . [ 2 ] 20, 200-20r5') .--The author has repeated Fremy's research on plumbic acid ( A ~ L ~ L . PJys. Chew [3], 12, 490), partly confirming his results. Potassium pZumbate, R,Pb03 + 3H,O, crystal lises in quadratic pym- mids ; n : c = 1 : 12216. The crystals are efflorcscent and are not isomorphous with potassium stannate. The sodium salt has not been obtained in a state of purity. Potassium plumbate does not produce a precipitate in alkaline solutions of tin and aluminium, but impure ylumbates are thrown down on boiling a solution of the potassium salt with lime, baryta, and magnesia.The precipitate which separates out when an alkaline solution of lead oxide is added to potassium plumbate is the hydrated sesquioxide, and not Pb30d, as stated by Fremy. The precipitate is conlpletely soluble in hydrochloric acid ; when treated with nitric or acetic acid, or with a hot solution of potash, lead di-oxide remains undissolved. By F. S E m m m (Ber., 12, 20@-2068).-When a piece of platinum is heated to redness in IL w. c. w. Volatility of Platinum in Chlorine.MINERALOGlCAL CHEMISTRY. 95 glass 01- porcelain tube, through which a current of chlorine ispassed, crystals of the metal are deposited o c the sides of the tube. A suhli- mate of platinurn is also obtained by exposing a porcelain flask con- taining platinous chloride to a bright red heat.The author discusses the bearing of these experiments on the abnormal densitv of chlorine a t high teGperatures ob'served by V. and C. RIeyer (Be1-.~"12~ 1426). w. c. w. Note.-In a recent communication (Ber., 12, 2202), V. Ncyer states that, under the conditions in which his experiments were con- ducted, platinum does not volatilise. He also points out that Seel- heim's explanation cannot account for the abnormal vaponr-density of iodine: since in these determinations iodine and not platinum iodide was employed. w. c. w.INORGANIC CHEMISTRY. 89I n o r g a n i c Chemistry.Allotropie Modifications of Hydrogen, By J. THOXPEN (BeT-.,12, 203O).-The author points out that ‘l’ominasi’s statement (Acr~tl.Illi’lun), that the heat of fcrmation of potassium chlorate is 9,760,and that of potassiuni chloride 104,476 units, and consequently104,476 - 9,760, i.e., 94,716 heat-units, are alisorl~ecl in the conversionof potassium chlorate into chloride, contains no less than three errors.The heat of formation of potassium clilorate is 95,840, and not 9,760,the latter number representing the lieat evolved in the convcrsion ofpotassium chlorate into chloride in the dry way.Instead of 94,716heat-units being sbsosbod in the reduction of the chlorate to the chlo-ride, a liberation of 15,370 heat-units takes place. It is obvious thatthe theoretical speculations based on these incorrect data are valueless.A New Method for Prepaxing Hydriodic and HydrobromicAcids. By G.BRUYLAN‘TS (Be?.., 12, 2Wl-2062) .-Hjdriodic acidcan be easily prepared by heating a solution of iodine (2u grams) incopaiba oil (60 grams) in a retort connected with an upright condenser.The gas is purified by passing it through a drying tube. When theevolution of gas slackens, fresh iodine is brought into the retort, andthe process is continued until about 1.50 grams of iodine have beenused.In the preparation of hydrobromic acid by this method, the brominemust be slowly dropped into the retort containing the oil, and the gasshould be purified by passing through three drying towers.w. c. w.w. c. w90 ABSTRACTS OF CHEMICAL PAPERS.Influence of Volume and Temperature in the Preparationof Ozone. A New Ozoniser.-By A. R .LEEDS (A~WUZA~L, 198, 30-42) .-A solution of potassium dicbromate (not necessarily saturated)mixed with sulphuric acid is placed in a suitable vessel, within which abell-jar can be placed, and pieces of phosphorus are partly immersed inthe liquid. It is better, however, to connect three such jars and drawthe air through them by means of an aspirator.For this purpose, thenecks of the jars are cernented into brass caps, which are screwed to itbar capable of being raised and lowered as in a gnlvanic battery ; thestoppers are replaced by corks covered with paraffin, through each ofwhich pass three glass tubes, one ending just below the stopper,another just above the liquid, and the third bent into a horizontal ringat the end. The first two tubes are connected so as to allow a currentof air to be drawn through the apparatus ; the third is for lowering ormising the phosphorus.The pieces of phosphorus are melted .inwatch-gla$ses to give them w more convenient shape, and are placedon glass plates in glass cells in the liquid. A flexible tube for con-veying the ozone from the generators was made of “ cei-ite” (“ kerite-”schlauch), and found to answer rery well.The maximum amonntof ozone obtained was a little over 2.5 mgrms. per litre of air ; but a sthe generator may be connected with the aspirator and allowed towork for any length of time, the s~ipply is unlimited.A Possible Cause of Variation of the Proportion of Oxygenin the Air. BF E. W. ~\~ORT,EY (Chew. News, 40, 184-186, and1 !49-20l).-Looniis has proposed the theory that certain great andsiidden depressions in the temperature of the atmosphere are causedhy the velatical descent of currents of air from cold elevated regions.If such is the case, then the air at the surface of the earthduring suchdepressions may contain a smaller amount of oxygen than the a;c-erage.Jolly concludes from his experiments that the air a t the equator ispoorer in oxygen than that a t tjEie polar regions, owing to the amountof oxygen consumed in oxidation being greater than that liberated byreduction. Facts, however, do not confirm these conclusions, no dif-ference in the composition of the atrnosplicre of the two regions havinghithertc been detected.According to the author’s views, based on Loomis’ theory, air col-lected at the centre of an area covered by a descending current would,a t a given moment, be a sample fresh from the upper atmosphere;whilst a sample collected on one side of this centre would consist of amixture of s w f m e and wpper air, but still containing a deficiency ofoxygen.Although the author has not yet succeeded in making theseexperiments, he has, while laying plans for the ~ o r k , conducted espe-yiments on ordinary air, to ascertain what light can be thrown 011 thechanges in composition of the atmosphere. The apparatus used wasconstructed on McLeod’s modification of Frankland and Ward’s appa-ratus, with important modifications, so as to reduce all causes of errorto a minimum.The samples were collected in the open country, in glass vessels. andpreserved over mercury freed from carbonic anhydride, and exploclcvlA temperature of 24” gives the best results.G.T. AINORGANIC CHEMISTRY. 9Jwith pure hydrogen. Some samples were collected in stoppered andc;ipped bottles, which were inverted, and the caps filled with water.Analyses of air were made daily from 28th December, 1878, to GtlhApril, 1879, during ivhich period some very marked and sudden de-pressions of temperature occurred, which were accompanied by adecrease in the quantity of oxygen. The deficiency, however, as mighthave been expected, was not proportional to the decrease i n tempe-rature (see also p. 85 of this volume).By G. WOLFRBX (AmnZe/r,198, 95--98).-IGimmerer ( J . pi..Chem., 90, 190) has desribed amethod according to which perbroinic acid may be obtained br theaction of d ~ y bromine on clry perchloric acid, the latter being preparedi\ t the tlime by the decomposition of potassium perclilorate by sulphuricacid. The author has repcated this experiment, and finds tliat the:icid thus obtained, corresponding in all respects with that describedhy Kammerer, is nothing more than a mixture of percliloric andsulphuric acids. The apparent absorption of the bromine by tlieperchloric acid is explained by the fact that perchloric acid, whenheated with an excess of sulphuric acid, is decomposed into oxygenmid chlorine, and it is this latter which takes u p tlie bromine i n theabove experiment, forming bromide of chlorine : this is volatilised,together with the excess of bromine, during the subsequent concen-tration of the liquid.L.T. 0's.Preparation of Perbromic Acid.T. C.Researches on Nitrous Acid and Nitrogen Tetroxide. By G.LUNGE (Dingl. yoZyt. J., 233, 155-165; cornp. this Journal, Abst.,18'79, 770).-8econd Pa7-t.- Oti the Re7at;ow of the Acids OJ hTitrogetl to,Sulplm-ic ileitZ.-Our knowledge of this relation is not by any weanscomplete. It is well known that nitrous acid, either in the liqnicl orgaseous form, o r jmduced nascent from the union of nitrogen dioxidewith oxygen, is clissolved by sulphuric acid of about. 1.7 sp. gr. ; butthe heliaviour of nitrogen tetroxide towards snlphuric acid is not accu-rately known. The author has shown that it is dissolved by sulpliurici~cid, forming nitrosulphuric and nitric acids ; but according to Weberand Winkler, nitlogen tetroxide is dissolved as such by sulphuric acidof 66" B., producing a reddish-yellow solution, which, when heated,gives off nitrogen tetroxicle with violcrit ebullition, and leaves a liquidIiaviug the properties of nitrosulphuric acid.Winklcr stated that28 072 grams of sulphuric acid a t 60"B. absorbed 7.307 grams ofnitrogen tetroxide, but that on heating gently, the latter was eiitirelyexpelled. Weber describes the effects of nitrogen tetroxide onsulphui*ic acid of different specific gravities, but only qualitativel~ :thns, sulphuric acid at, a sp. gr. of 1.7 absorbs nitrogen tetroxidewithout becoming coloured: liecce i t was assunied that the latterwas decomposed; a t a sp.gr. of 1.55 the sulphuric acid becomesyellow, and hence it was supposed that the greater part of thenitrogen tetroxide was simply dissolved. Acid of 1-49 sp. gr. takes agreenish-yellow colour; acid of 1.41 sp. gr. takes an intense greend o u r ; acid of 1.31 sp. gr. becomes blue and liberates nitrogen dioxicle,which escapes with violent ebullitioii on gently heating. The p e l 92 ABSTRACTS OF CHEMICAL PAPERS.and blue colours were supposed to be due to the formation of nitrouswid, the nitrogen tetroxide having been decomposed into that sub-stance and nitrogen dioxide. As these results are very important tovitriol manufacturers, the author studied them more accurately, and,its far as possible, quantitatively.The nitrogen tetroside, preparedfrom d r g fused lead nitrate, was measured oif from a burette, andmixed with pure sulphuric acid, which had been diluted to differentstrengths with water, and the effects of heat upon these mixtureswere also noted.The following are given as examples of the mctliod employed and ofthe results obtained by the author in carrying out the expel-iments :-100 C.C. sulphuric acid of 1-84 sp. gr., t o which was added 2 C.C.= 3 grams liquid nitrogen tetroxide, gave a colourless solution with:L very feeble odour, recaJling that of ozone. The amount ofnitrogen dioxide evolved from 1 C.C. of this solution in the nitro-meter was determined, and also the amount required to decolorise10 C.C. seniinormal potassium permangmate solution.From theresults, the author calculates that his nitrogen tetroxide contained ofpure nitrogen tttroxide 93 per cent., and of nitric acid 7 per cent. ; butlie argues, as in reality the nitrogen tetroxide does not exist, as such inthe sulpliuric acid, but has undergone a decomposition, one part oftlie tetroxide having been converted into nitric acid a t the expense ofthe oxjgen of the other part, whilst the part which has been robbedof its oxygen remains as nitrous acid in combinatlion with tlie sul-phuric acid; then assuming that this lower oxide takes the oxygenfrom, and decolorises the potassium permanganate, this would wive46.5 per cent. as nitrous acid, and 53.5 per cent. as nitric acid. ?'heother calculations are niade on this supposition, that is, it8 is firstassumed that all the nitrogen tetroxide remains as such, and the defi-ciency in the theoretical amount of oxygen required is calculated asnitric acid; but if, on the contrary, tho amount of oxygen requiredbe less than that found by the permangnnate process, then he assumesthat no nitric acid is present, but that nitrous acid must have beenoriginally present as an impurity.(I.) The acid was heated to 2tiUo, and kept at that temperature for onehour ; any free nitrogen tetroside, if it were present, must have beenthus expelled.When the ttmperature rose t o 20Uo, R little red vspourwas evolved, and the liquid acquired a golden-yellow colour ; b u t oncooling, it again became colourless.On analysis the author calculated that 77.9 per cent.of the nitrogenpresent existed as N,O,, and 21.1 per cent. as HNO,; there is, con-sequently, he si;tys, a large amount of the nitric acid driven off andanobher part changed into nitrous acid.(11.) On continuing t o heat for one hour longer, a further changetook place of the bame kind, and 94..5 per cent. of the nitrogen re-maining existed as Nz03, in combiliation with the sulphuric acidjorming nitrosulphnric acid ; whilst 5.rj per cent. remained as HNO;;,n~ld 18 per cent. of the nitrogen originally present having been ex-pelled by the heating.(111.) Another experiment was made by adding pure nitric t o pu:.TN ORGANIC CHEMISTRY. 93sulphuric acid, and analysing the resulting mixture, but no change wasfound to have taken place.(1V.) On boiling the mixture for half-an-hour, however, red fumeswere given off, and the whole of the nitrogen present was convertedinto nitrous acid, which was found in combination with the sulphuricacid.That nitric acid is thus broken up has also been demonstrated inanother way by Winkler, who collected the oxygen which was evolvedfrom the decomposition.The author did not find the same result as Winkler with sulphuricacid of 66OB.above mentioned, and he explains this by assuming that,Winkler employed so much nitrogen tetroxide that it left it hrgt.excess beFond that which could combine with the sulphuric acid asnitrous acid : hence the sudden and violent ebullition and liberation ofnitrogen tetroxide on heating the mixtuye.2 C.C.nitrogen tetroxide added to sulphuric acid of 1.805 sp. gr. washroken up into practically the same proportions of nitrous and nitricacids as in the first experiment, with acid of 1.54 sp. gr.Other experiments are described in which sulphuric acid of1.75 sp. gr. was mixed with nitrogen tetroxide and then heated ( a ) , sothat the vapour evolved might a t once escape, and ( b ) where a longtube was attached to the flask in which the mixture was heated, sothat the vayoar might condense and flow back again to the acid inthe flask. In ( a ) nitrous acid, but no nitric acid mas found, whilst in ( b )nitric acid was present but no nitrous acid ; this is explained by the fact,that it requires concentrated sulphuric acid to combine with andretain the nitrous acid ; and in ( a ) the acid became concentrated byevaporation, whilst in ( b ) it remained of about the same sti.eugth, aridwas unable to retain the nitrous acid.Again, when the mixture was heated on a water-bath a t about 95",no such changes occurred.As Winkler found, that on heating his mixture of acid of 60°B.with nitrggen tetroxide, the latter was evolved, he presumed that i texisted as a mechanical mixture with the acid.This the author denies,stating that had Winkler examined the acid a,fter boiling, he wouldhave found that it contained nitric acid, and that the nitrogentetroxide had really undergone decomposition ; and further, that homust have heated it considerably above the temperature of boilingwater, otherwise no change would have resulted, and no red fumeswould have been liberated.When the amount of nitrogen tetroxirle added is in excess of thatrequired to form nitrnsulphuric acid, the author is uncertain fromanalysis whether it exists in the acid in the form of nitrous acid orof nitrogen tetroxide.W. T.Norwegium. By T. DAHLL (Rer., 12, 15'3 1-1 732) .-The prepam-tion of this metal from the ore has already been described (thisJournal, Abs., 1879, 890). It melts a t 254', and its atomic weight is145.552 (RO), or 218.928 (TC2G3). It can be separated from bismuth,which it closely resembles, by the solubility of its oxide in alkalis anda1 kaline carbonates. w. c. w94 ABSTRACTS OF CHEMICAL PAPERS.Constitution of Antirnonic Acid.By P. CONRAD (C'henz. News,40, 197--198).-With a view t o decide the constitution of antimonicwid, specimens of it were prepared from the pure metal by sevendifferent methods, and carefully analysed.The antimony was determined as snlphide, with the usual precau-tions, whilst the water mas determined, tint by exposure over sulphu-yic acid, and iheii by heating in a slow stream of nitrogen, andcollecting the wder in a weighed calcium chloride tube. The sub-stance was weighed after heating, and any discrepancy between theloss of weight by the substance and the water expelled, was regardedas due to the reduction of the oxide. The loss of water takes placeverg gradually.The acid dried over sulphnric acid a t the ordinary temperature hasthe constitution Sb,05.3H,0, whereas the acid dried in a current ofdry air a t the ordinary temperature is represcnted by SbL0,..5H,0.At loo", this loses 3 mols.H20, Sb,05.H,0 being formed ; and between100" and 200" one more mol. H,O is expelled, leaving Sb,0,.H20.Contrary to the statement of Daubrawa (Amrden, 186, l l O ) , theanhydrous pentoxide is not formed at 2 i 5 " , and even a t 300" the pro-duct still contains + a mol. H,O. This is driven off only a t a, red heatwhen the oxide begins to decompose.There seems to be reason t o believe in the existence of three anti-moriic acids, corresponding with three acids of pliosphorus-Orthonntimonic acid, H3Sb04 = 3H,0.Sb205.Pyroantimonic acid (nietaritimonic acid, Fremy) H4Sb,O7 =Meta-antimonic acid (antimonic acid, Fremy) HSbO, =2HzO.Sb205.H20.SbZOj.The gradual formation by heat of the second and third acids fromthe first is similar to the formation of the corresponding acids of phos-ph oras.L. T. 07s.Salts of Plumbic Acid. By 0. SEIDET, ( J . pr. C h L . [ 2 ] 20,200-20r5') .--The author has repeated Fremy's research on plumbicacid ( A ~ L ~ L . PJys. Chew [3], 12, 490), partly confirming his results.Potassium pZumbate, R,Pb03 + 3H,O, crystal lises in quadratic pym-mids ; n : c = 1 : 12216. The crystals are efflorcscent and are notisomorphous with potassium stannate. The sodium salt has not beenobtained in a state of purity. Potassium plumbate does not producea precipitate in alkaline solutions of tin and aluminium, but impureylumbates are thrown down on boiling a solution of the potassium saltwith lime, baryta, and magnesia.The precipitate which separates out when an alkaline solution oflead oxide is added to potassium plumbate is the hydrated sesquioxide,and not Pb30d, as stated by Fremy. The precipitate is conlpletelysoluble in hydrochloric acid ; when treated with nitric or acetic acid,or with a hot solution of potash, lead di-oxide remains undissolved.By F. S E m m m (Ber., 12,20@-2068).-When a piece of platinum is heated to redness in ILw. c. w.Volatility of Platinum in ChlorineMINERALOGlCAL CHEMISTRY. 95glass 01- porcelain tube, through which a current of chlorine ispassed,crystals of the metal are deposited o c the sides of the tube. A suhli-mate of platinurn is also obtained by exposing a porcelain flask con-taining platinous chloride to a bright red heat. The author discussesthe bearing of these experiments on the abnormal densitv of chlorinea t high teGperatures ob'served by V. and C. RIeyer (Be1-.~"12~ 1426). w. c. w.Note.-In a recent communication (Ber., 12, 2202), V. Ncyerstates that, under the conditions in which his experiments were con-ducted, platinum does not volatilise. He also points out that Seel-heim's explanation cannot account for the abnormal vaponr-density ofiodine: since in these determinations iodine and not platinum iodidewas employed. w. c. w