ii. 16 ABSTRACTS OF CHEMICAL PAPERS. Inorganic Chemistry. Action of Hydrogen Peroxide Solution on Lime-water and Iodine Preparation of Ammonium Iodide. T. C. K. BROEKSMIT (Pharnz. Weekblad 1917 54 1373-1374).-1n pres- ence of hydrogen peroxide solution iodine reacts with lime-water t3 form the iodide with evolution of gas and formation of only a trace of iodate. With ammonium 'hvdroxide the reaction takes place in accordance with the equationi ZNH -t- I + H202 = ZNH,I i- 0,. A. J. W. Reaction between Ozone and Hydrogen Peroxide. VICTOR ROTHMUND and ALEXANDER BURGSTALLER (Xonatsh. 1917 38 295-303. Compare A. 1913 ii 773).-The velocity of the reac- tion between ozone and hydrogen peroxide has been examined in O*OlN-sulphuric acid solution a t Oo the two substances being sepa- rately estimated in the reaction mixture by the method described in a previous paper (A.1913 ii 524). I n presence of relatively large quantities of hydrogen peroxide the reaction may be represented by the equation H,O + 0 = H20 + 20 and the rate of disappear- ance of the ozone follows closely the equation f o r a unimolecular reaction. When the ratio of hydrogen peroxide to ozone is smaller the ozone disappears more rapidly than the hydrogen peroxide and this inequality in the quantities of ozone and hydrogen peroxide which are destroyed in a given interval of time increases as the concentration of the hydrogen peroxide is reduced.INORGANIC CHEMISTRY. ii. 17 The facts suggest t h a t the interaction between ozone and liydro- gen peroxide is accompanied by the spontaneous decompositiou of ozoiie and t h a t hydrogen peroxide acts as a powerful catalyst in respect to the latter reaction.This theory also offers an explana- tion of previously recorded observations on tlie rate of decomposi- tion of ozone in dilute sulphuric acid solution (compare A. 1913 ii 489) for it is highly probable that the ozonisation of oxygen Is acconipaiiiecl by tlie f orination of traces of hydrogen peroxide. H. M. D. The Valencies of Nitrogen. FRANZ WEEXGEL (MonutsIL. 191'7 38 267-293) .--The author considers t h a t no conclusive evidence has yet been put forward in support of the view t h a t four of the nitrogen valencies bear the same relation to the fifth. Whilst certain chemical observations suggest that there are two pairs of valencies which are identical in relation to the fifth valency pkysico-chemical data seem t o indicate t h a t there are three valen- cies which are identical with regard to the fifth valency.From this it is inferred that the fifth valency does not always represent one and tile same valency unit. -4n zt'tempt is made to account f o r the behaviour of nitrogen corapounds on the assumption t h a t the valencies of nitrogen are ciivisibie into two distinct groups one1 of which includes two and the other three valencies which are equal in all respects. When quicquevalent nitrogen is transformed into tervaleiit nitrogen there is a 109.; of one valency from each group. This change is supposed to result in the formation of an intra-atomic double linking con- necting dissimilar nuclei.In support of this theory attention is directed t o the similarity between the amines and ethylene deriv- atives in respect of their capacity to form additive compounds. It is said that this hypothesis affords a satisfactory account of the clieinistry of nitrogen compounds. H. M. n. Disodium Nitrite an Additive Compound of Sodium Nitrite and Sodium. EDWARD BRADFORD Bfmmn (T. 19 17 1 1 1 1016-1019).-When solutions of metallic sodiuni and sodiuni nitrite in anhydrous ammonia are mixed together a blrilliant yellow substance is precipitated which has the composition Na,NO,. Tlie same substance is deposited on the cathode when a solution of sodium nitrite in perfectly anhydrous liquid ammonia is sub- jected to electrolysis. The subst aiice is decomposed vigorously by water with the formation of sodiuni nitrite sodium hydroxide and hydrogen.By passing a current. of moist nitrogen over the rli- sodium nitrite the action is niocleratetl and the resulting solutioii is found to be free froiii liydroxylaniine and liyponit8rite. H. M. 1). Formation of Large Crystals in Zinc Rods and Wire. W. FRAENKEL (Zeitsch. Elektrochem. 1917 23 302-304).-It has been observed t h a t large crystals are often found in zinc rods which have been worked mechanically. Tlie author describes experiments VOL. CXIV. ii. 2ii. 18 ABSTRACTS OF CHEMICAL PAPERS. iiiade with the object of ascertaining the conditioiis under wliicli these large crystals are formed aiid the reasons for their formation. Rods of zinc of varying diameter were subjected to a temperature just below the melting point of zinc for some time and after cooling were broken and the structure of the break examined.I n some cases it was found that a recrystallisation of the metal had oc- curred and t h a t the cross-section of tlie break consisted of a single crystal whilst in other cases only sniall crystals were observed. The author suggests possible explanations of the phenomenon but is unable to decide on any one of the suggestions as the cause. A nuiiiber of microphotographs of sections of zinc rods before and after treatment are given in the paper. J. F. S. Action of Hydrogen Peroxide on the Neutral Salts of Lead. V. ZOTIER (Bzrll. SOC. chin?. 1917 [iv] 21 241-243. Compare A. 1913 ii 216 465).-Neutral lead salts exert a more or less marked catalytic action on hydrogen peroxide.Using hydrogen peroxide (100 vcls.) the catalysis is intense with soluble organic salts and feeble with insoluble organic salts or mineral salts. With lead acet'ate one portion of the hydrogen peroxide yields lead peroxide which tlien reacts with the remainder of the hydrogen peroxide and a t the end of the reaction there is no lead peroxide left. If the solid salt is used the catalysis is a t first moderate but soon becomes violent and the mass becomes hot. The presence of acids lessens o r hinders the catalysis by hindering the preliminary formation of the lead peroxide. [See also J . SOP. C'heni. Ind. 1918 37 7 ~ . ] W. G. Some Compounds of Lead. V. ZOTIER (BzilI. SOC. chzm 1917 [iv] 21 244-246. Compare A.1913 ii 216 465 and preceding abstract).-Pure lead peroxide may be prepared by the addition 'of hydrogen peroxide t o a solution of lead nitrate in 2076 sodium hydroxide. Hydrogen peroxide may be used to differen- tiate between a normal and a basic lead salt. With the former it does not give any residual lead peroxide but with the latter it does. Alkaline solutions of lead salts may be used as a delicate test for hydrogen peroxide or conversely hydrogen peroxide in the presence of sodium hydroxide may be used as a delicate test for lead. Contrary to the general opinion i t is found that lead peroxide is slowly attacked by mineral acids or aqueous solutions of alkali hydroxides. The process is in all cases very slow the rate varying with the acid or alkali used.By heating together a t 150° equal weights of lead nitrate and 50?L sodium hydroxide an amorphous red lead is obtained but if the proportion of lead salt is halved and the temperature raised t o 160O. a microcrystalline red oxide is obtained. [See also .7 Sor. Chc??~. Id. 1918 37 7A.1 W. G . The Dissociation Constants of Mercury Hydroxides. I. 31. KOLTHOFF (Cheru. TT-eellibZctcZ 1917 14 1016-1022).-TheINORGANIC CHEMISTRY. ii. 19 clissociation of mercury hydroxide solution is a step-by-step proce3s asid can be represented by the scheme I ~ ~ ( o H ) = rTEow OH'; H ~ O T I * = H ~ * = 1 OH/. A . J IT. Quantitative Investigations on the Corrosion of Resistant Glass by Sodium Hydroxide. C. J. VAN NIEUWENBURG (Chenz. Tl'eekblcd 191 7 14 1034-1040).-A comparison of the effects produced by heating sodium hydroxide solution in Jena and 1,;cborax flasks.A. J. W. The Production of Colloidal Base Metals by Reduction of Solutions or Suspensions of Compounds at Higher Temperatures in the Presence of Protective Substances. Colloidal Nickel. C1. Km,nm (BPI.. 1917 80 1509-1512).-The knowledge that near 200° nickel oxide and some nickel salts can be reduced t o nietallic nickel by hydrogen has been applied to the production of colloidal nickel by reducing solutions or suspensioiis in glycerol containing gelatin or gum arabic as a protective colloid. For example a solution of nickel forinate and gelatin in glycerol a t 200-210° when submitted to the action of a stream of hydrogen assumes a chestnut-brown colour. The colloidal solution remains uiialtered in the air and is miscible with alcohol but on treatment with water and centrifuging deposits the colloidal metal as a dark brown solid containing 25-30% of nickel which can again yield colloidal nickel solutions in dilute acetic acid acidified water glycerol or alcohol.Other reducing agents can be applied to the same purpose ; nickel formate a t 220° in glycerol solution in the presence of gelatin is reduced by Iiydrazine hydrate with formation of a colloidal nickel solution of similar properties t o that just described. Formaldehyde hydroxylamine and hypophosphorous acid can also be applied as reducing agents for the purpose whilst gum arabic can be used in place of gelatin. The nickel formate can be replaced by nickel acetate or freshly precipitated nickel hydroxide. ISO- and Hetero-poly-acids. XV. Critical Researches on the Constitution of the Hetero-poly-acids. ARTHUR ROSENIIEIN and JOHANNES JYNICKE (Zt~it.~-7t. a ~ o t . g . P l l e ~ ~ . 1917 100 304-354. Compare R. 1913 i 413; ii 59; 1914 ii 58; 1915 ii 266 468; 1916 ii 333 334; 1917 ii 35).-A historical and theoretical paper in whicli the crystallographic physical and chemical properties of thc? iso- and hetero-poly-acids are summarised and t,lie whole of the prtxious work is discussed. The earlier theories on the constitution of these acids are reviewed. including the application of Werner's co-ordination theory. The last is found to be unsatisfactory but t h e modification of this theory suggested by Miolati (A. 1908 ii 595) and extended by Rosenheim provides the most satisfactory elucidation of the constitution of these substances. n. F. T. E. H. R.