INORGANIC CHEMISTRY. Inorganic Chemistry. ii. 131 Early Work on Hydrofluoric Acid and the Isolation of Fluorine. FREDERICK D. CHATTAWAY (Cliem. News 19 13 107 25-26).-Historical. Reactions of Ozone with Certain Inorganic Salts. YOSHITO YAMAUCHI (Amel.. Chem. J. 1913,49,55-6S).-A study has been made of the action of ozone on certain inorganic salts with the object of ascertaining whether the oxidation is effected by only one oxygen atom of the ozone molecule or whether all three atoms take part in the process. A method has been devised by which each sample of ozonised oxygen can be divided into two parts one for carrying out the experi- ment and the other for analysis. The salts employed included potassium arsenite stannous chloride sodium thiosulphate thallous nitrate mercurous nitrate and ferrous ammonium sulphate.I n the case of stannous chloride the oxidation takes place according to the equation 3SnCJ2 + 6HC1+ 0 = 3SnC1 + 3H,O but in all the other cases only one oxygen atom of the ozone molecule reacts with the salt the ozone decomposing thus 0 = 0 + 0. When sodium thiosulphate is treated with ozone two reactions occur one involving the catalytic decomposition of the salt 3Na,S,O = 3Na,SO + 3S and the other effecting a partial oxidation of the sulphite formed 2Na,SO + 30 = 2Na2S0 + 20,. Thallous salts are rapidly and corn pletely oxidised by ozone and the thallic oxide produced can be readilii. 132 ABSTRACTS OF' CHEMICAL PAPERS. collected and weighed; the reaction is therefore applicable to the estimation of ozone.E. G. The Dynamic Allotropy of Sulphur. IV. HUGO R. KRUYT (Zeitsch. physikal. Chern. 1913 81 726-748. Compare A. 1908 ii 1028; 1909 ii 228 802).-The paper is chiefly polemical. It is shown that mixed crystals are formed by Sp and SX and that the transition S -+ S,,,. takes place a t a higher temperature in the presence of Sp. The transition point of pure Srh. is 95-3' whereas the generally observed transition point is 95.5' and the triple point S)+, S,,,. and Sliq lies a t 95.9Ok 0.1'. Attempts are made to calculate the transition point of rhombic sulphur on the basis of Nernst's theorem but this led to results which are in no way like the experimentally- determined values. An answer is given to the paper8 of Wigand (A. 1910 ii 602 1055) Snits and Leeuw (A. 1912 ii 40) Leeuw (this vol.ii 40) Preuner and Schupp (A. 1909 ii YS7) and to Wo. Ostwald (Grundriss der Kolloidchemie p. 132). The following thermal constants of sulphur are collected in the paper; these are held to be trustworthy. If. p. monoclinic sulphur (free from Sp) 119.25'. M. p. monoclinic sulphur as usually prepared 114.5'. M. p. rhombic sulphur (free from Sp) 112.8'. M. p. rhombic sulphur as usually obtained 110.2'. M. p. of nacreous variety of sulphur (free from Sp) 106.8". AX. p. of nacreous variety of sulphur as generally obtained 103*4O. Transition point Srh. -+ S,,,,,. (free frolu Sp) 95.3'. Transition point usually obtained 95.5' (3.1% Sp present). J. F. S. The Chemistry of t h e Formation of Nitric Oxide in the High Tension Arc. FRANZ FISCHER and EMIL HENE (Uer.1912 45 3652-3658).-The purely thermal formation of nitric oxide from nitrogen and oxygen has been questioned by various investigators (cotn- pare Haber and Koenig A. 1908 ii 34 940 ; Grau and RUSS A. 1907 ii 753). Escales in a discussion before the German Bunsen Society (Zeitsch. Elektrochsm. 1906 12,%539) raised the question whether the formation of nitric oxide might not be preceded by the activation of the nitrogen but Strutt has since shown (A 1912 ii 153) that active nitrogen does not react with oxygen. The authors now show that the energy of the discharge is probably used up i u dissociating the oxygen molecules this being an endothermic process. Outside the arc the following processes which are exothermic then take place (1) re-formation of molecular oxygen (2) oxidation of molecular oxygen to ozone (3) formation of nitric oxide.The latter may be a direct reaction between the active oxygen atoms and the nitrogen or may be due to a reaction between the ozone and the nitrogen which reaction would be exothermic. The above conclusions are based on the following experiments. When pure oxygen is sparked as i t passes out of a quartz capillary and mixes with pure nitrogen in a closed apparatus six and a-half times more nitric oxide is produced than when the nitrogen is sparked and mixeswithINORGANIC CHEMISTRY. ii. 133 oxygen. Similarly when air is sparked and blown into oxygen four time+ as miich when blown into nitrogen twice as milch nitric oxide is produaed as when pure nitrogen is sparked and blown into pure umparked oxygen.A higti-tension arc was produced in a quartz apparatu! cooled with wat,er. When air was sent through the arc and then mixed imme- diately with oxygen air and nitrogen respectively the volume percentages of nitric oxide produced were respectively 7.8 7.4 and 5.9. When air is submitted to the silent discharge i n a quartz Siemens ozone tribe heated a t varying temperatmws (20-7@0°) the percentage of nitric oxide pnbduced incl eases with rise in temp.eritture owing to the increased velocity of reaction between any ozone produced and the nitrogen reaction taking place before the ozone is destroyed by the high temperature. The above results indicate that better results would be obtained on a manufacturing scale if oxygen were paqsed through the arc flame instead of air u-ing magnetite electrodes and then rapidly mixed with nitrogen and cooled.T. S. P. The Inner Cone of Hydrocarbon Flames. FRITZ HILLER (Zeitsch. ylrysihcd. Cham. 1913 81 591-625. Clomprre A. 1910 ii 122).-A further investigation of the inner cone of certain flames. The ethrr and coal-gas flames are chiefly investigated and the analyses of the products of combustion a t the poiit of the cone the bide of the cone and at different positions aoove the cone in the space between the inner and outer cone are made. Tem- perature determinations were made by means of an iridium iridium- rhodium couple and these valries were compared with the teruperatrires calculated from the compo-ition of the gas in the sp’ce betweeu the two cones and the known specific heats and heats of cornbuytion on the one hand and with those obtained from the equilibrium constant and it.; relation t o temperature on the other Considerable difficulty was experienced in the calculations owing t o the uncertainty of the therm-tl data required for obtaining the temper- ature.The constant K= (H,O/CO,)*(CO/H,) is given for all experi- ments the various values bring obtained by gas analyticdl processes. The eqriilibrium constant is found t o be about 3.4 when the gtses coming from the inner cone are cooled to a temperature which allows of no further change but when the cod gas has been previously mixed with carbon dioxide the equilibrium constant is considerahly lower than 3.4 I n the ctse of the ether flbrne this constant is often found t o be as low as 2.8 the higher value only being obtainable when a very small flame is employed.J. F. S. The Various Forms of Silica and their Mutual Relations. CLAHENCE N. FENNER (J. Washhgton Acad. Xci. 1912 2 471-480).- The velocity of transformation of one form of silica into another is extremely slow and the different forms may exist together over considerable ranges of temperature. The inversions may be hastened VOL. civ. ii. 10i. 134 ABSTRACTS OF CHEMICAL PAPERS. by employing a catalytic agent (sodium tungstste). inversion points were determined from t,he heating curves gonal) 555'. The following P-quartz (Izemihedral hexa- a- Quartz ( t etartohedral hexagonal) /3 Quartz 7 /3-tridymite (holohedral hexagonal) 870'k 10'. P-Tridymite P-cristobalite (cubic) 1470°k 10'.On cooling P-tridymite and P-cristobalite promptly pass a t the foll(iwing temperatures into metastable forms possessing lower optical symmetry P-TI idymite Z a-tridgmite (biaxial perhaps orthorhombic) 1 1 5 - 1 20'. /3-Cri~tobalite a-cristobalite (biaxial) 180-270'. Chalcedony possibly represents a seventh form of silica. L. J. S. The Transformations of Silica at High Temperatures. KURD ENDELL aud KEINHOLD RIEKE (Zeitsch. unory. Chem. 1912 79 239-259).-'l'he present investigation deals with pure temperature cbangev in the absence of mineralisers. The specimens of native silica in fragments of 1-3 C.C. and also in powder are heated in a n electric furnace and the direction of the tramformation determined by measurements of t h e density using the dataD (quartz) 2.65 (cristobalite) 2.33 (silica glass) 2.21.Quartz and chalcedony which have been heated at 1450' have often been described a8 optically isotropic owing to the microscopic cracks produced during the tranhformation which also give rise to an error in the determinations of density. Cristobalite is best recognisd by its change of volume at about 230' measured in a mercury dilato- meter. Quartz and amorphous silica are converted into cristobalite by heat- ing above 800' but an exact temperature of transformation has not beeu fouud. Tbe velocity of conversion increases wit'h the temperature. Between 1200' and 1600' the transformation of silica glass is propor- tional to the time. Twinned quartz is converted more rapidly than simple crystals and chalcedony still more rapidly.Using an iridium furnace P-cristobalite is fouud to have m. p. 1685' + 10'. The factor determining the rate of tramformation is the extent of surface a twinned crystal having a greater effective surface than a simple one and fibrous varieties such as chalcedony a still greater surface. The quartz of pegmatite and graphic granite is often repeatedly twinned. Chalcedony may be regarded as a n unstable transitional form of quartz. Massive rock crystal may probably be melted by rapid heating without previous conversion into cristobalite. The present data do not allow of the construction of an equilibrium diagram for silica but an attempt is made t o classify the various modifications in accordance with Tammann's hypothesis (A 1912 ii 149).C. H. D. This is the only means of distinguishing it from tridymite. Capacity of Potassium Haloids for F o r m i n g Solid Solutions at High Tumperatures. MARIO AMADORI ( A t t i K. Accad. Lzncei 1912 [v] 21 ii 606-610 Compare A 1912 ii 758).-The author has repeated some of his former experiments with results which con-INORGANIC CHEMISTRY. ii. 135 firm those obtained by him and Pampanini (A 1912 ii 48) and not agree with those of Vrshesnevsky (A. 1912 ii 137). The author's conclusions are further supported by recent work of Nacken and Schobert (Diss. Leipzig 1912) and Nacken and Elack (unpubliahed). R. V. S. Some P r o p e r t i e s of Alkali Nitrites. MARCEL OSWALD (Compt. rend. 1912 155 1504-1506).-The author has prepared sodium and potassium nitrites in a high state of purity and examined their pro- perties.Sodium nitrite when heated in a vacuum melts a t 217' (compare Divers T. 1899 75 86) and decomposes at 320' ; potassium nitrite melts at 29'7.5O and decomposes at 350'. After firsion and resolidification they have respectively Di 2.168 and 1.912. The densities of their solutions a t various concontratiom are given. W. G. The Silver-Zinc Equilibrium. HENRY C. H. CARPENTER and W. WRITELEY (Internat. Zeilsch. Metahgraphie 19 12 3 145-1 69). -The eqiiilibrium diagram given by Petrenko (A. 1906 ii 284) is incompatible with the phase rule. It I S shown that the errors in the diagram are due to the use of insufficient quantities of material t o want of uniformity and t o the absence of proper annealing.The system has now been reinvestigated using larger quantities and employing greater precautions. The actual diagram is of a much simpler character. The liquidus has been determined accurately by Heycock and Neville (T. 1897 '71 407). The limits of the a-solid solution a t 220' (determined on samples annealed for six weeks) a r e 100 and 62.7 atomic 7; of silver. The p-constituent is unstable below 264O at which temperature there is a eutectoid point -+ a+y. The y-constituent is the compound Ag2Zn3 ; i t is highly brithle and develops conspicuous cleavage cracks A t 260' the y-range is from 40 to 37.3 atomic % Ag. The 6 constituent (probably Ag2Zn5) which is also brittle has a range 29 to 14.3 atomic % Ag whilst the y-con- stituent is confined to the immediate neighbourhood of the zinc end of the series.There is thus a very close resemblance throughout the whole system between the copper-zinc and silver-zinc series. The Copper-Zinc Silver-Zinc and Silver-Cadmium E q u i l i b r i a HENRY C. H. CARPENTER (Irderncct. Zeitsch. illetaZlogrupl& 191 2 3 170- 175).-A remarkable similarity is observed bet ween the equilibria in the systems copper-zinc (A' 1912 ii 764) silver-zinc (preceding abstract) and silver-cadmium (Petrenko and Fedorov A. 1911 ii 281 800). The €-constituent does not exist below 3 1 0 O . C. H. D. In each case a compound of similar composition cu2zn3 Ag2Zn3 Ag,Cd determines the form of the diagram. The a-solid solutions have a similar range of stability and near to the compositions CuZn AgZn and AgCd /3-constituents occur having a comparatively wide range of composition at a high temperature narrowing with falling tempera- ture until a eutectoid point is reached at or about 50 atomic %. The y-constituent is in each case the pure compound.It is remarkable 10-2ii. 136 ABSTRACTS OF CHEMICAL PAPERS. t h a t the systems copper-tin and copper-aluminium also include a /3-constituent stahIe only above a certain t3emperature and then undergoing a eutectoid inversion. The copper-cadmium diagram does not shorn any close analogy with the above. C. H. D. The Preparation and Investigation of Silver Oxide. E. HOST MADSEN (Zeitsch. anorg. Chern. 1912 79,195-201).-Silver oxide has not hitherto been obtained in a pure condition. A concentrated solution of silver nitrate is precipitated with a dilute solution of sodium hydroxide and the precipitate is washed with water previously freed from carbon dioxide.It is then dried at 85-88' in a stream of air free from carbon dioxide. The product contains 1.75% of silver hydroxide (0.1 25% of water) and about 0.5% of silver carbonate. Some reduction takes place as whilst the moiht precipitate yields a white chloride with hydrochloric acid even after exposure to light the dry solid always yields n red chloride the colour af which is deeper the higher the temperature of drying. At 280' the water is almost completely expellcd but i t is not possible to obtain a product of constant weight as appreciable dissociation of the oxide takes place. C. H. D. The oxide dried at 8 5 O is dark brown with a violet s5ade.Cement Limestones of Santa Marinella. NICOLA PARRAVANO (Gazxetta 19 12 42 ii 6 10-6 17).-The paper records analyFes of a number of specimens from this district (which lies south of Civita- vecchia) carried out to determine the suitability of the stones for the manufacture of Portland cement and gives the results of tests applied t o the cements made from them. E. v. s. Gelatinous Cdcium Sulphate and the Setting of Plaster. CAVAZZI (Gazxetta 191 2 42 ii 626-632).-When calcined calcium sulyhate is treated with water a gelatinous calcium sulphate is first Formed which in a few minutes at low temperatures and more rapidly at higher temperatures turns into crystals of CaSU,,2H20. The gelatinous salt can be observed t o crystallise under the microscope and i t is identical with that produced by the addition of alcohol to a supersaturated solution of calcium sulphate.That the setting oE plaster is not due to the crystallisation of CaS0,,2H20 from a super- saturated solution is shown by the fact that the lncrease of volume on setting is very much less than t h a t which is found to occur when this salt is allowed to crystallise from a supersaturated solution. R. v. s. The R61e of Calcium Sulphate and Barium Sulphate in the Reduction of Zinc Minerals. EUG~NE PROST and MAURICE UBAGHS (Bull. SOC. chim. Belg. 1912 26 532-541. Compare A. 1911 ii 283).-1n the presence of silica the sulphates of calcium and barium have a marked influence on the reduction of zinc minerals. They consume a large amount of heat for their decomposition or reduction and in the presence of silica react with it generating sulphurousINORGANIC CHEMISTRY.ii. 137 vapours which in contact with the zinc vapour cause the formation of zinc sulphide which remains in the distillation residue thus increas- ing the loss of zinc the sulphide only being reduced a t a much higher temperature. The presence of silica is necessary for the formation of zinc sulphide as in its absence the calcium and barium sulphides formed by the reduction of the corresponding sulphates do not yield their sulphur t o the zinc oxide of the roasted blende at the experi- mental temperature of 1200' (compare Netalluygis 191 1 8 763). W. G . Glucinum Phosphates and Glucinum Phosphite and Hypophosphite. BENNO BLEYER and BR. MULLER (Zeitsch.anorg. Chem. 1912 79 263-276. Compare A. 1912 ii 644).-Mono- ylucinum orthpJLosphate GlH,(PO,) prepared from the hydroxide and oi*thophosplioric acid forms colourless hygroscopic leaflets. Diglucinuiii orthophosphate GlHPO,,SH,O,. has not beon obtained free from adhering phosphoric acid. l'raylucimun orthophosphate GI,P,O,,GH,O obtained from disodium phosphate acetic acid and glucinum sulphate forms a loose precipitate. 2G1,P,08,G10 13H,O is obtained when trisodium phobphate is used €or precipitation. Potassium plucinum orthophosphabe and also the correspor,ding sodium and ammonium salts have only been obtained as precipitates of variable composition. The gliicinum phosphates previously de- scribed in the literature are mixtures. Glucirtum pyrophosphate GI,P,07.9H,0 is precipitated by means of sodium pyrophosphate.Gl,P,O 2Na,P20,,5 H ,O is a soluble hygroscoiic salt. Glucirmm metaphosphate Gl(PO,) forms colourless crystals and must be prepared in absence of water otherwise a basic salt is obtained. 4G 1HPc),,G10,7H20 and hypophosphite GlH,P,O have also been prepared. A basic salt Sodium glucinum pyrophosphate Glucinum phosphite C. H. D. Magnesium Ions as Oxygen Carriers. OTTO HAUSER (Chem. Zeit. 1913 37 58).-l'he ruhting of iron is accelerated by the presence of nlagnesium ions. I n general reactions which take place with absorption or evolution of oxygen are similarly accelerated. The effect of magnesium ions is best shown in the oxidation of hydro- chloric acid or chlorides by permanganate. T. S. P. Thermal Analysis of Binary M i x t u r e s of Chlorides of Bivalent Elements.IV. CARLO SANDONNINI ( A t t i R. Accc6c.d. Lirtcei 1913 [v] 21 ii 634-640. Compare A. 1912 ii 1172).-The present paper deals with the thermal analysia of the system M gCI,-SrC'l MgC1,- BaCI and MgCl,-MuCI,. The magnesium chloride used contained 1.1 1% of oxide which was allowed for in calculating the compositions of the mixtures dealt with Magnesium chloride and strontium chloride do not seem to form solid solutions; there is a n eutectic corresponding with 535' and 50 mols. % of strontium chloride.ii. 138 ABSTRACTS OF CEIEMICAL PAPERS The system MgC1,-RaCI is analogous to the system MnCI,-BaCI already studied. There is an eutectic corresponding with 36 mols. % of barium chloride and about 556'.Mixtures containing more barium chloride show a pause at 590° as well a s that of the eutectic; if the amount of barium chloride is increased only this upper pause is observed but if the amount is still further raised the pause falls amgain until it coincides with the eutectic. These indications point to the production of a compound decomposing on fusion. Magnesium chloride and manganese chloride are completely soluble both in the solid and in the liquid state and mixtures of them melt at temperatures intermediate between those of the constituents The author discusses the regularities which may be perceived in the thermal behaviour of the biuary mixtures of chlorides of bivalent elements investigated by himself and others. R. V. 5. [Metastable Metals ] E. B.WOLFF (Zeitsch. Elekhochem. 19 13 19 19-23. Compare Cohen A 1909 ii 1008).-Polemical. The author shows that an etching solution does not convert a metal which has been rendered metastable by deformation into the stable condition. The action is shown to be the removal of the deformed and metastable surface layer with the exposure of the stable underneath layer. It is also stated in opposition t o Cohen (Zoc. cit.) that a metal which has been rendered stable by etching is unable to innoculate other metal which has been subjected to deformation. J. F. S. [Metastable Metals.1 ERKST COHEN (Zeitsch. Elektrochem. 191 3 19; 23).-Polemical. A< answer to Wolff (preceding abstract). J. F. S. Physico-chemical Studies on Red Lead. JAROSLAV MILBAUER (Chem. Zed. 1912 36 1436-1437 1484-1485).-By means of a specially designed apparatus the author has investigated the formation of red lead from lead oxide under oxygen pressures varying from 1 to 12 atmospheres and a t temperatures from 325' t o 520".The results show that the equilibrium is independent of the pressure but is attained more rapidly with increasing pressure One hundred yo of red lead is formed at 470-480' the percentages being less above and below this temperature the time of experiment being in all cases three hours. T. S. P. The Structural Resolution of the Pure Copper-Zinc p-Constituent into a+y. HENRY C. H. CARPENTER (J. I n s t . Metals 1912 8 51 -58).-The p-constituent of alloys of copper and zinc which undergoes transformation at 4.70' during cooling (A. 1912 ii 764) does not segregate even after annealing for several months at 4 4 5 O although the presence of minute quantities of either the a- or 7-constituent brings about segregation much more rapidly.Repeated quenching in liquid air brings about the traiisitory development of a duplex structure the nature of which is unknown. Resolution of the P-alloy at 445' is brought about by contact with an ay-alloy of copper and zinc containing 0.95% of vanadium. C. H. D.INORGANIC CHEMISTRY. ii. 139 The Effect of Other Metals on the Structure of the ,&Constituent in Copper-Zmc Alloys. HENRY U. H. CARPENTER (J. Irhst. Metccls 1912 8 59-85).-‘rhe resolution /3 - a + y. which takes place in alloys of copper and zinc at 470’ (A. 1912 ii 764) is afiected by the presence of other metals in the alloy.Met& which are insoluble in the solid alloy such as lead and chromium are witbout influence but bismuth has .been found in one case to accelerate the resolution Antimony tin aluminium silicon and vanadium which enter into solid solution displace the eutectoid composition to the y-side and assist the resolution. Iron has much less effect. Nickel and manganese have little effect. C. H. D. Copper-Zinc-Nickel Alloys. LBON GIULLET (Compt. rend. 19 12 155 1512-1514. Compare A. 1905 ii 168).-A study of the influence of nickel when added t o certain brasse.;. It is found that the additim of nickel considerably improves their mechanical proper- ties and gives them a “fictitious” proportion of zinc considerably higher than their real proportion (compare A 1906 ii 357).W. G. Constitution of Aluminates. EDWARD G. MAHIN D. C. INGRAHAM and 0. J. STEWART (J. Amer. Chem. Soc. 1913 35 30-39).-The solubility of aluminium hydroxide in alkali hydroxide solutions and t b e existence of minerals containing the oxides of aluminium and certain other metals in apparently coristant proportions have led to the hypothesis that aluminium hydroxide is amphoteric. &lust of the investigations on the aluminates have been directed to the determination of their formulse and have given varying results; they have also shown that the quantitative relations between the alkali metal and aluminium differ according to the method of preparing the solution. I n view of these facts the present work WAS undertaken in order t o ascertain whether the solubility of aluminium hydroxide in alkali hydroxides is not due rather t o its colloidal properties than t o its amphoi eric chnracter.Measurements of the heat of solution of aluminium hydroxide in solution of sodium hydroxide a quantitative study of the action of ammonium nitrate on a solution of sodium aluminate and observations on the behaviour of sodium aluminate on electrolysis have been made. The results iudicate that the solubility of aluminium hydroxide in alkali hydroxide solutions depends very largely on its colloidal proper- ties and that it is doubtful whether aluminates have any existence as definite salts. E. G. The Heusler Ferromagnetic Alloys of Manganese. FRIEDRICH HEUSLER (Zeitsch. anyew. Chem. 191 2 25 2651-2653).-A claim for priority against Wedekind (this vol.ii 55). C. H. D. The Formation of Nitrogen Oxides by Heating Manganese Dioxide in Air. PAUL ASKENASY aud E. L. RENYI (Zeitsch. Elektro- chvrn. 1913 19 23-32).-The statement made by Odier (J. phys. chim. 1798 464) t h a t oxides of nitrogen are produced when manganeseii. 140 ABSTRACTS OF CHEMICAL PAPERS. dioxide is heated in oxygen is investigated. The authors heated natural and artificial manganese dioxide in a current of air a t various temperatures. It was folind that very small quantities of oxides of nitrogen were evolved which never amounted to more than 0.2 mg. nitric oxide from 10 grams of manganese oxide. The oxides made their appearance a t 280° but on beating for several hours ceased to be formed. On raising the temperat.ure 4 fresh quantity was produced.Ahove 700" no oxide could be obtained. The authors draw the con- clusion t h a t the oxides of nitrogen are not formed from atmospheric nitrogen since the same results could be obtained by suhstituting a current of carbon dioxide for that of air. They are of the opinion that the nitrogen is furnished by the manganese dioxide which probably contains a nitrogen compound to the extent of 0.002%. J. F. S. The Passive State of Iron. JAMES MACLEOD-BROWN (Chem. News 1913 10'7 15).-It is fIequentlgasserted that if part of an iron nail or mire ib rendered passive the remainder of the nail or wite also asstimcs this state. That this is not SO may be shown as follows An iron nail three inches long is immersed t o a delltli of one inch in con- centratrd nitric acid.The nail is allowed to drain and the other end imruersed to a depth of one inch in dilute nitric acid when it will be found to be active; the passive end remains passive. If the nail is lowered into the dilute nitric acid passive end fir& the whole of it becomes passive after a short time. Other experiments are described in which it is shown that when a passive iron nail is connected by means of a platinum or copper wire to a nail of ordinary iron the two nails being immersed i n dilute nitric acid that part ot the ordinary iron which dips into the nitric acid becomes pashive after a short time the passivity being produced by anodic polarisation. The author considers that the passive state is conditioned by some definite arrangement of the particles at the surface of the ixon.T. S. P. Equilibria in Quaternary Systems. VI. Quaternary Alloys of Iron Nickel Manganese and Copper. NICOLA PAHEAVANO (Gazaetta 1912 42 ii 589-609. Compare A. 1912 ii 1175 ; this vol. ii 33 55 58).-In the present paper which dors uot letld itself to abstraction the author summarises the results which he haH already obtained (loc. cit.) in the thermal study of the binary and ternary systeuis included in the nhove quaternary bystem and referring to a former theoretical discussion or" quaternary sy*tems (this vol. ii 33) he establishes theoretically the charavteristics which bhould be displaj ed by this quateraary bystem. The experimental pibrt wt1it.h is accou yanird by numerous tables diagrams and photomic:rl,grapbs gives the resulLs of the experimental verification of these theorer ical previsions.R. V. S. Determination of the Atomic Weight of Uranium. WILLIAM (ECHSNER DE CONINCK (Co,mpt. rend. 1912 155 1511-1512).-AINORGANIC CHEMISTRP. ii. 141 determination of the atomic weight of uranium by ignition of anhydrous uranyl oxalate and weighing the residual uranium dioxide. The mean of seven determinations gives the value 238.4 for the atomic weight of uranium. W. G. The Oxides of Uranium. WILLIAM CECHSNER DE CONINCK and ALBERT RAYNAUD (BUZZ. SOC. chim. 1912 [iv] 11 1037-1038).- When uranium formate covered with a layer of methyl alcohol is exposed t o the action of diffused daylight f o r three months uranous oxide (UO,) is deposited and formic acid formed.When urnnous oxide is heated in the air.to a bright red heat the oxide U,Ol0 is produced. T. S. P. The Basicity of the Tungsto-acids. HIPPOLTTE COPAUX (Conrp!. reud. 1913 156 71-75.. Compare Ann. China. Phys. 1912 [viit] 25 22).-The author has determined the conductivity of acids of the type of phosphoturrgstic acid in very dilute solutions and from his results deduced the b:tsicity of the acids. Silicotungstic acid is tetrabasic and even a t high orders of dilution is practically unhydroly sed. I t s isomwide tiingsto~ilicic acid and its isomorph silicomolybdic acid are also tetrabasic and not hydrolysed on dilution. Bot*otungstic acid is pentabasic this being in agreement with its known sodium barium and cadmium salts Aletatungstic acid is hexitbasic but is appreciably hydrolysed i n very dilute solutions.Pbosphotungstic acid is freely hydrolysed on dilution and whilst the composition of i t s ordinary salts and its analogy to other acids point t o its being tribasic the conductivity seems to reach a limit for a basicity of five. Phosphomolyhdic acid is tribasic but in moderately dilute solutions gives values for a tetrabasic acid seemingly due t o hydrolysis of the acid yieldiag two dibasic acids which the author suggests is represented by the equation H3[ P( M~~207),j€14] + 2 H20 = H ,[P( MO,O,)~(OH),H,] + H,MO,O~. I n geueral the corriposition of the soluble salts of strong basss is a criterion of the basicity of tungsto- and molybdo-acids and the value so obtained is in accord with that obtained by conductivity methods.Disagreement is a sign of hydrolysis of the acid on dilution. W. G. The System Tin. ANDREAS SMITS and H. L. DE LEEUW (Proc. K. Aknd. Wetcnsch. Amsterdrcvn 19 12 15 676-68l).-'l'he prohable existence of a transition point for tin in the neighbourhood of 20U" is indicated by a number of observations and in particular by t h e experiments of Werigin Lewkojev and T;irrimanri (Ann. Physik 1903 [iv] 10 147) on the rate of flow of tin under preasure. The fact that Cohen aud Goldschmidt (A. 1905 ii 268) obtained no evidence of the existence of the tramition point in dilatornetric expeliruents is now showu to be due in all probability to tbe slowness with which the change in qliestion takes place and new observatioiis with a dilatometer axe recorded which indicate that the temperature of the reversible change tetragonal tin ZZ rhombic tin is 202.8".Smallii. 142 ABSTRACTS OF CHEMICAL PAPERS. quantities of mercury act as a catalyst but a t the same time the transition temperature is depressed In the presence of 0.12 and 0.22% of mercury the temperatures obtained by the dilatometric method mere 173' and 151' respectively The occurrence of this chitnge at 202%' accounts for the brittleness developed when tin is heated to about 2110° The transition temperature of 170' deduced by Cohen and Goldschmidt from the flow experiments referred to above is based on a n erroneous interpretation of the data in question there being no evidence whatever for the occurrence of any change a t this tempera- ture. H. M. D. The System Tin-Iodine.K. S. VAN KLOOSTER (Zeitsch. aizorg. Chem. 1912 '79 223-229. Compare Reinders and de Lange this vol. ii 60).-Stannous iodide SnI m. p. 321° is practically im- miscible with molten tin at 400'. Stannic iodide SoI m. p. 1 4 3 O mixes in all proportions with iodine the eutectic point being at 1 2 atomic % of t i n and 76'. Stannous iodide is only slowly formed from its components even at 440' in a sealed tube. Stannous iodide crystallises in ruby-red needles D: 5.21. Crystallo- graphic measurement* [by F. M. Jaeger] show that the crystals are monoclinic a c = 1 0.5911 /3 = 83'55''. C. H. D. Thorium Compounds. FRANZ HALLA (Zeitsch. anorg. Chem. 19 12 79 260-262).-8 mixture of anhydrous t.lioriurn sulphate and magnesium carbonate mir h a little water yields a sandy precipitate of basic thoyiurn sulphnte ThOS0,,5H20.The same salt is obtained as a flocculent precipitate by the action of magnesium sulphate on a boiling solution of thorium sulphate or nitrate. The titration of thorium nitrate with potassium hydroxide and phenolphthalein is complete when 3.5 mols. KOH are present for 1 atom Th. With the basic sulphate the hydroljsis proceeds to the same stage It is not possible to wash thorium hydroxide free from sulphate by means of dilute ammonia. The addition of ammonium carbonate to a mixed solution of magnesium chloride and thorium nitrate yields a transparent emulsion the globules of which change to a hard glans on drying. Magnesium hydroxide and thorium sulphate or magnesium sulphate and thorium hydroxide yield a n opalescent jelly.C. H. D. ThOSO KOH = 1 1.75. The Preparation of Metallic Vanadium. 111. WILHELM PRANDTL and HERMANN MANZ (Zeitsch. anorg. Chem. 1912 79 209-222. Compare A.. 1909 ii 1022; 1910 ii 1075)-The vanadium obtained by Ruff and Martin (A. 1912 ii 166) by heating the trioxide with carbon in an electric vacuum furnace is only apparently purer than that obtained by the aluminothermic process the slag which is always present having been deducted in the course of Ruff's analyses. The addition of calcium fluoride in the aluminothermic process is not essential. Vanadium pentoxide gives better results than theINORGANIC CHEMISTRY. ii. 143 trioxide the higher temperature obtained favouring the elimination o€ slag. The presence of alkali is harmful as alkali vanadltte passes into the slag and an excess of aluminium remains.The attempt has been made to remove oxygen from the product by the addition of vanadium hydride prepared by heating electrolytically disintegrated vanadirim in hydrogen at 1000' (Muthmann Weiss and liiedelbauch A. 1907 ii 781) but a liydride has not been obtained the increase i n weight being due merely t o combination with oxygen and nitrogen. The reduction of vanadium trichloride with sodium in slight excess also yields a product containing about 96% of metal. Alumioothermic vanadium (95%) has D 5,987 and 96% metal from the chloride and sodium has D 5.819. C. H. D. The Annealing of Coinage Alloys. THOMAS K. ROSE (J. Inst. Metals 19 12 8 86-1 25).-The softening of metals and alloys hardened by mechanical treatment takes place at any given tempera- ture at first rapidly and then more slowly but at temperatures approaching the melting point it is almost instantaneous.The change is accompanied by recrystallisation. The formation of new crystals at 200' in the case of gold is too rapid to b3 accounted for by diffusion. The softening is accompanied by expansion which is greater in alloys than in pure metals. C. H. D. Condition of Gold in Gold Quartz. P. P. VON WETMARN (Zeitsch. Chem. Irzd. Kolloide 1912 11 287-290).-1f 0.1 to 1% solutions of sodium auric chloride and sodium silicate are mixed a clear solution is obtained which gradually develops a reddish colour and this changes slowly and finally becomes blue. Coagulation commences after several months and the microscopic examination of the coagulum has shown a close similarity in structure with that presented by the gold in auriferous quartz.H. M. D. Some Anomalies Observed in the Assay of Platinum Ores from Ural. H. C. HOLTZ (Ann. Chim. Phys. 1912 2'7 559-566).-The process employed is briefly as follows the mineral is treated with aqucc regia which leaves a residue composed of sand and a compound of osmium and iridium The solution is evaporated t o dryness the residue treated with hydrochloric acid and again evaporated and dried at 130' to reduce the iridium chloride to the ous-state. After dissolving in water the platinum is precipitated quantitatively by addition of excess of ammonium chloride and from the filtrate the other metals (iron excepted) are then precipitated by adding a little hydrochloric acidand a sufficiency of pure zinc. After weighing the deposit ('' blacks ") is treated with dilute nitric acid (1 l) which dissolves the palladium and copper.From this solu- tion the palladium is precipitated by means of mercuric cyanide; the excess of mercury is got rid of by ignition preferably after evapora- tion with hydrochloric acid and the copper precipitated finally as copper thiocyanate. Now on applying the process t o a mixture of the chlorides of platinum iridium palladium rhodium and copper theii. 144 ABSTRACTS OF CHEMICAL PAPERS. results were quite satisfactory but when assaying the ‘‘ Ural ore ” the following anomalies were observed. (1) The “ b l ~ c k s ” are not totally dissolved by the nitric acid (2) The copper oxide (after expelling the excess of mercury) is not completely soluble in hydrochloric acid. (3) The filtrate from the copper thio- cyanate is yellow and gives a dark precipitate on addition of zinc. From further experiments it seems that ( a ) ‘l’he oxide of this mysterious substance is insoluble in hydrochloric nitric nitrohydrochloric and sulphuric acid. ( b ) The oxide dissolves in aqueous sodium hydroxide with a yellow colour. This solution remains bright yellow on adding hydrochloric acid and does not react with potassium iodide ; stannous chloride decolorises it. (c) When fused with oxidising mixture the oxide is not attacked and a colourless mass is obtained. ( d ) The dark product (3) is reduced t o metal by ignition in a current of hydrogen with slight loss in weight. (e) The metal is dissolved by melting with potassium hydrogen sulphate yielding a brownish-red mass which does not give a white turbidity with water (absence of rhodium). (f) It is soluble in nitric acid and its hydrochloric acid solution is not precipi- tated by amrxioniulu chloride. These properties taken in conjunction with similar experiences of other writers lead the author t o believe that another unidentified element is present iu the Ural ore. L. DE K.