摘要:

J O U R N A L A. CHASTON CHAPMAN. A.W.CEOSSLEY,C.M.G.,D.SC.,F.R.S. M. 0. FORSTER D.Sc. Ph.D. F.R.S. A. HARDEN DSc. Ph.D. F.R.S. 1’. A. HENRY D.Sc. C. A. KEANE D.Sc. Ph.D. G. T. MORGAN D.Sc. F.R.S. OF J. C. PHILIP O.B.E. D.Sc. Ph.D. W.J.POPE C.B.E.,M.A.,D.Sc.,F.R.S. F. L. PYMAN D.Sc. Ph.D. A. SCOTT M.A. D.Sc. F.R.S. S. SMILES O.B.E. D.Sc. F.R.S. J. F. THORPE C.B.E. D.Sc. Ph.D. F. R. 9. THE CHEMICAL SOCIETY. G. BARGER M.A. D.Sc. ’ H. W. BYWATERS D.Sc. Ph.D. H. M. DAWSON Ph.D. D.Sc. C. H. DESCEI D.Sc. Ph.D. W. GODDEN B.Sc. E. GOULDING D.Sc. H. B. HUTCHINSON Pl1.D. G. F. MORRELL Ph.D. D.Sc. T. S. PATTERSON D.Sc. Ph.D. T. H. POPE KSc. T. SLATER PRICE D.Sc. Ph.D. ABSTRACTS OF PAPERS ORGANIC PHYSIOLOGICAL AND AGRICULTURAL CHEMISTRY. ON E. H. RODD D.Sc. S. B. SCHRYVER D.Sc. Ph.D. W. P. SKERTCHLY. F. SODDY M.A. F.R.S. J. F. SPENCER D.Sc. Ph.D. L. J. SPENCER M.A. R. V. STANFORD M.Sc. Ph.D. D. F. TWISS D.Sc. A. JAMIESON WALKER Ph.D. B. A. J. C. WITHERS Ph.D. H. WREN M.A. D.Sc. Ph.D. 1918. Vol. CXIV. Part I. LONDON GURNEY & JACKSON 33 PATERNOSTER ROW E.C. 4. 1918.Abstractors of the Journal of the Society of Cheinical I%dt&ry who have contributed to this volume. J. F. BRIGCIS. T. F. BURTON B.Sc. L. A. COLES. W. F. FREW. H. J. HODSMAN. J. H. JOHNSTON. C. A. KING. J. )I. LANE. C. A. MITCHELL. B. NORTH. A. B. SEARLE. A. SHONK. F. C. THOMPSON.

ISSN:0368-1769    

DOI:10.1039/CA91814FP001

出版商:RSC    

年代:1918

数据来源: RSC

摘要:

J O U R N A L A. CHASTON CHAPMAN. A.W.CROSSLEY,C.M.G.,D.SC.,F.R.S. M. 0. FOKSTER D.Sc. Ph.D. F.R.S. A. HARDEN D.Sc. Ph.D. F.1C.S. T. A. HENRY D. Sc. C. A. KEANE D.Sc. Ph.D. G. T. MORGAN D.Sc. F.R.S. OF J. C. PHILIP O.B.E. D.Sc. Ph. D. W.J.POPE,C'.B.E.,M.A.,D.S~.,F.R.S. F. L. PYMAN D.Sc. Ph.D. A. SCOTT M.A. D.Sc. F.R.S. 8. SMILES O.B.E. D.Sc. B.R.S. J. F. THORPE C.B.E. D.Sc. Ph.D. F. R. S. THE CHEMICAL SOCIETY. C. H. DESCH D.Sc. Ph.D. W. GODDEN R.Sc. E. GOULDING D.Sc. ABSTRACTS O F PAPERS F. SODDY M.A. F.R.S. J. F. SPENCER D.Sc. Ph.D. L. J. SPENCER M.A. ON PHYSICAL INORGANIC MINERALOGICAL ANALYTICAL CHEMISTRY. AND 1918. VoL CXIV. Part 11. LONDON GURNEY & JACKSON 33 PATERNOSTER. ROW E.C. 4. 1918Abstractors of the Journal of the Society of Chemical Industry who have contributed to this volume. J . F. BRIGIGS. F. F. BURTON B.Sc. L. A. COLES. W. F. FREW. H. J. HODSMAN. J. H. JOHNSTON. C. A. KING. J. H. LANE. C. A. MITCHELL. B. NORTH. A. SHONK. F. C. THOMPSON. A. B. SEARLE. PRIN'CED IN GREAT URITAIN BY RICHARD CLAY & SONS LIMITED L?HUNSWICK ST. YTAYFORD ST. Y.E. 1 AND BUNGAY SUFFOLK.

ISSN:0368-1769    

DOI:10.1039/CA91814FP003

出版商:RSC    

年代:1918

数据来源: RSC

摘要:

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.

ISSN:0368-1769    

DOI:10.1039/CA9181405016

出版商:RSC    

年代:1918

数据来源: RSC

摘要:

ii. 20 ABSTRACTS OF CHEMICAL PAPERS. Analytical Chemistry. New Form of Safety Pipette. A. K. REFIRMAN ( J . h l . Eng. Chem. 1917 9 1047).-A three-way tap is attached to the top of an ordinary pipette by means of a short length of rubber tubing and a rubber bulb fitted with suitable valves is connected with the upper limb of the tap. The pipette is filled by pressing and releasing the bulb. The tap is then turned so as t o admit air t o the pipette by which means tlie level of the liquid is lowered t o tlie Preparation of Ammonium Citrate Solution and the Estimation of Insoluble Phosphoric Acid. PHILIP McG. S'HUEY ( J . Ind. Eng. Chein. 1917 9 1045).-Neutrral ammonium citrate solution may be prepared by dissolving 1814.37 grams of citric acid in 6961 C.C. of water and 1760 C.C.of 28% ammonia the water and aniinonia being measured a t 2 3 O . The insoluble phos- phoric acid in acid phosphate may be estimated with practically identical results whether or not tlie weighed portion has been washed previously with water and preliminary washing of samples coil- taining cyanamide does not appear to be necessary. T t may be im- portant t o use a neutral ammonium citrate solution in the case cf ground tankage whale guano meat guano fish and similar mate- w. P. s. Micro-method for the Estimation of Inorganic Phos- phates in the Blood-serum. W. MCKIN MARRIOTT and F. H. HAESSLER ( J . Rid. Chem. 1917 32 241-243).-Full details of the method previously described (compare Howland Haessler and Marriott A. 1916 ii 269). The Perchlorate Method for the Estimation of the Alkali Metals.F. A. GOOCII and G. R. BLAKE ( A n z e ~ . J. Sci. 1917 [ivl 44 381-386. Compare A. 1917 ii 270).-Tn this method i t is unnecessary t o use an alcoholic liquid saturated with the substance to be precipitated since the volunie of the solution (97% alcohol containing 0.1% of percliloric acid) used for washing the precipitate may bel so restricted that the solubility of the precipitated per- clilorates is insignificant. A single evaporation with a moderate excem of perchloric acid (0.1 C.C. for each 0.1 gram of salt) is not sufficient to convert considerable quantities of alkali chlorides (for example 0.3 gram) completely into perchlorate ; the residue should b3 treated with a further quantity of perchloric acid and again evaporated.For the separation of large amounts of insoluble per- chlorates from sodium perchlorate the washed precipitate should be dissolved in a small volume of water and the evaporation with perchloric acid repeated. I n the case of rubidium perchlorate the precipitate should be digested for fifteen minutes with the alcoholic washing solution. It is to be noted that perchloric acid has a dis- tinct solvent action on glass. [See also J . SOC. Chem. Ind. 1918 mark a d then delivered. w. P. s. rials which have not been strongly acidified. H. W. B. 37 214.3 w. P. s.ANALYTICAL CHEMISTRY. ii. 21 Micro-method for the Estimation of Calcium and Mag- nesium in Blood-serum. W McKni MARRIOTT and JOHN HOWLAND (*7. R i d . ( ' h ~ m . 1917 32 233-239).-Full details of tlis niethtl previoiisly descrihtl (cortipare Rowlniicl Haeusler anil Marriott A .191G ii 269). €1. IV. 13. Estimation of the Metal Content of Powdered Metals. F. HODES (Zeitsch. nngezu. Chem. 1917 30 240).-The quantity of metallic tungst.en in powdered tungsten which has been prepared reduction with carbon may be estimated by igniting a portion o f the sample in an open crucible; the increase in weight is due t o oxidation of the metal to tungsten trioxide. As however the pow- dered metal usually contains small quantities of carbon and mois- ture i t is necessary to heat anotlier portion of the sample in a current of oxygen weigh the amounts of carbon dioxide and water given off and correct the first weight accordingly. w. P. s. Iodometric Estimation of Copper and Iron.HERM. LEY (Clmn. Zeit. 1917 41 763).-Soluble cupric and ferric salts both liberate iodine from potassium iodide in acetic acid solution and the iodine set free is a measure of the amount of cupric and ferric salts present. When it-is desired t o estimate copper in the p r e ~ n c ~ of iron the latter may be precipitated as ferric phosphate which is irisoluble in acetic acid and does not react with potassium iodide; ci:pric phosphate however is readily soluble in acetic acid. The solution containing the cupric and ferric salts is treated with sodium phosphate solution then acidified with acetic acid potassium iodide is added and the iodine is titrated with thiosulphate solution. The ferric salt is estimated by treating another portion of the original solution with potassium iodide and acetic acid and titrating the liberated iodine; the difference between the volumes of thiosulphate solution used in the two titrations is equivalent t o the quantity of ferric salt present.Aluminium and zinc do not interfere. IT. P. s. Sensitive Reaction of Hydrogen Peroxide depending on the Formation of Dihydroxytartaric Acid. G. DENIG~S (,4nn. C?iim. c1)iaZ. 1917 22 193).-A violet coloration is formed when a small quantity of dilute hydrogen peroxide solution is added t o a mixture of 2 C.C. of 5% tartaric acid solution and 2 drops o l 5% ammonium ferrous sulphate solution and the mixture then treated with 6 drops of sodium hydroxide solution. The reaction may be obtained with a quantity of hydrogen peroxide not exceed- w. P. s. ing 0.05 mg.Estimation of Glycerol by the Iodide Method using Small Quantities of Hydriodio Acid (Semimicro-iodide Method). R. NEUMANN (Zeitsclz. mzgezo. Chem. 191 7 30 234-237).-The author finds) that this method (compare A. 1902 ii 111 585; 1903 ii 515) yields trustworthy results when onlyii. 22 ABSTRACTS OF CHEMICAL PAPERS. about one-t,enth of t,lie usual quantities of sample and reagents are employed. Thp apparatus user1 has about one-eighth of the capa- city of t h e iodide apparatns d e s c r i h l hy Stritar ( A 1904 ii 95). w. P. s'. Oxidation of Organic Compounds with Chrorn ic Acid. A. WINDAUS ( Z e i t s c h . phgsiol. C'hem. 1917 100 lG7-1G9).- Certain organic compounds readily yield acetone and acetaldehyde when treated with chromic acid. The products can be separated by distillation and recogiiised by conversion into the comparatively iiisoluble p-nitrophenylhyrlrazones. In this way cholesterol coprost erol and sitosterol containing an isopropyl group can be readily clistinguished from the somewhat similar bile acids which do not yield any acetone or aldehyde when oxidised by chromic acid.Methylpentoses such as rhamnose are similarly easily detected in the presence of other pentoses and hexoses by means of the chromic acid oxidation test. The test must be carried out' under the prescribed conditions involving the use of a solution of chromic acid in glacial acetic acid. If an excess of sulphuric acid is sub- stituted for the glacial acetic acid lzvulose and even dextrose are found to yield acet,aldehyde and other volatile products which can form iodoform and iiisoluble 11-nitrophenylhydrazones (compare Engfeldt A.1917 ii 550). H. W. B. Formaldehyde as a Negative Catalyst in Sugar Reactions. H. MAGGI and G. WOKER (BPY. 1917 50 1331-1335).-Form- aldehyde hinders the reducing action of dextrose or maltose in the Moore-Heller and Rubner tests and especially the reduction of methylene-blue or picramic acid. Although formaldehyde has a more powerful reducing action on Nylander's solution than the sugars mixtures of them containing 1 C.C. of 40% formaldehyde to 0.5 C.C. of 1% dextrose or maltose do not affect this reagent. The aldehyde also hinders the reduction of Fehling and Pavy solu- tions by dextrose or maltose. J. C. W. Malic Acid and Citric Acid. T. C. N.BROEKSMIT (Phnm. TT'Pe?;bZnd 1917 54 1371-1373).-Both malic acid and citric acid answer to the iodoform test but can be distinguished by the fact that barium malate is not precipitated either in neutral solu- tion or in presence of acetic acid. A. J. W. Probable Accuracy in Whole Blood and Plasma of Colorimetric Estimations of Creatinine and Creatine. ANDREW HUNTER and WALTER R. CAMPBELL (1. R i d . Chen2. 1917 32 195-231. Compare Wilson and Plass A. 1917 i 360 and Gettler and Oppenheimer A. 1917 ii 184).-The authors have prepared a series of curves showing the rate a t which the colour utilised as the basis of a creatinine estimation develops not only in pure aqueous solutions but also in the various circumstancesii. 23 AXALYTICAL CHEMISTRY. in which it is applied to the analysis of blood.A coiupwisoii of these curves reveals the presence or absence of substaiices capable of producing a colour similar to that arising from creatinine. In plasma the only substance capable of simulating the reaction for creatinine is dextrose and its influence on the estimation of creatinine is shown to be too small to have much practical import- ance. I n whole blood however an unknown substance is present which although reacting more slowly than creatinine contributes in the Folin technique an appreciable fraction of the total colour developiiig within ten minutes. On laking the blood a much larger amount of this unknown substance is set free and passes into the protein-free filtrate. The filtrates from autocIaved blood or plasma also contain relatively large quantities of the substance which reacts similarly to creatinine.A consideration of these results indicates that although the Folin method estimates the preformed creatinine of plasma with a satisfactory approximation to accuracy the results obtained by the same method for the preformed creatinine of whole blood are on the average about 50% higher than the truth. The technique of Myers leads t o a still greater exaggeration of the preformed creatiiiine of blood. The Folin method for creatine whether applied t o whole blood or to plasma also gives decidedly erroneous results liable to be in the former case about twice and in the latter about four times as high as the amount actually present. H. W. B. Estimation of Faecal Indole. OLAF BERGEIM ( J .Biol. Chen~. 1917 32 17-22).-The fmes are mixed with potassiuni hydroxide solution and the indole distilled over in ail ordinary Kjeldahl dis- tillation apparatus Any ammonia in the distillate is removed by a second disttillation after acidifying with dilute sulphuric acid. The final distillate is treated with sodium B-naphthaquinone- sulphonate and alkali and the blue indole compound formed ex- tracted with chloroform and estimated colorimetrically (compare Herter and Foster A. 1906 ii 134 910). H. W. B. Improvement of the Volumetric Method of Estimating Albumin by means of Potassium Ferrocyanide. Presence of Rapidly Decomposable Proteins in certain Urines. ED. JUSTIN MUELLER (Bull. Sci. Plccrrrrincol. 1917 24 221-224 ; from C’kanz. Zentr. 1917 ii 325.Compare A . 1917 ii 555).-In the previous communication the author has described a method of estimating albumin in urine and pointed out that the immediate occurrence of the colour change with iroii alum (after addition of 3.5 C.C. of potassium ferrocyanide necessary for the saturation of the acidified water) is indicative of the absence of albumin. Sub- sequently however i t has been observed that the colour change can also occur in the presence of readily deconiposa,ble proteins. These differ from the albumins known in urology. They do not yield a precipitate when warmed or ~7he11 treated with acetic acid.ii. 24 ABSTRACTS O F CHEMICAL PAPERS. They are precipitated by warin trichloroacetic acid aud give pre- cipitates with cold trichloroacetic acid cold nitric acid and Esbach’s reagent which gradually dissolve when warmed.A cold solution of potassium ferrocyanide in acetic acid yields a pre- cipitate which is stable when warmed ; saturated ainmoiiium sulphate or sodium acetate solution gives a precipitate soluble in water whilst precipitates are not produced by sodium chloride or iiiagnesium sulphate. The prot eiiis are readily hydrolysed when warmed or in acetic acid solution. They are rendered more stable by addition of ammoiiiuin sulphate. For the volumetric estimation urine (50 c.c.) is treated with so much finely divided ammonium sulphate (8-9 grams) that a volume of 55 C.C. is attained; the solution is .filtered and 11 C.C. of the filtrate are used for the titration. H. W. Adaptation of Winkler’s Method to Biological Work.W. J. V. OSTERHOUT and A. R. C. HAAS ( J . B i o l . Chenz. 1917 32 141-146).-The apparatus consists of two glass tubes 30 cm. long and 27 mm. in diameter joined together by rubber tubing and furnished with rubber stoppers a t the free ends (all the rubber tubing and stoppers used in the apparatus should be coated with paraffin). One of the rubber stoppers is connected with a series of smaller glass tubes (13 mm. inside diameter) joined by rubber tubing with only enough space between them to permit the inser- tion of a clamp. The larger tubes are filled with the solution containing the organisins of which the oxygen metabolism is to be investigated. To estimate the oxygen in the solution a t any time the organisms are first allowed to gravitate to the bottom of the two tubes and then the lower one containing the organisms is clamped off and removed. The smaller tubes are then filled successively with alkaline potassinm iodide manganese chloride and concentrated hydrochloric acid each being separated from the other by means of the clamps. By releasing the clamps the reagents are successively introduced into the oxygenated solution and filially the contents are run into a beaker and titrated with thiosulphate as in Wiukler’s method for the estimation of oxygen i n solutions. The advantages claimed for the apparatus are that i t permits tlie reinoval of the organisms before adding the reagents and also the addition of the reagents without danger of contaminatioil by oxygen. Modifications are described whereby it is possible to take samples of the solution for analysis a t intervals during an experi- ment. H. W. B.

ISSN:0368-1769    

DOI:10.1039/CA9181405020

出版商:RSC    

年代:1918

数据来源: RSC

摘要:

ii. 25 General and Physical Chemistry. The Arc Spectrum of Tantalum on the International Scale. HEDWIG JOSEWSKI (Zeitsch. wiss. Photochem. 1917 17 79-96) .-Accurate me'asurements have been made of the wave- lengths of lines in the arc spectrum of tantalum between A7000 and h2430. The observations which are compared with those obtained previously by Exner and Kaschek also afford information relative to t'he intensity and the sharpness of the lines. There is no evidence of the occurrence of pairs of lines with a constant difference of frequency as suggested by Paulson (compare A. 1915 ii 196). H. M. D. The Photographic Spectra of Meteorites. SIR WILLIAM CROOKES (PhiZ. Trans. 1917 [ A ] 217 411-430).-The spectra of thirty meteorites have been examined with the aid of a spectro- graph characterised by certain novel features which are described.The use of a quart'z slit has given very satisfactory results the difficulty attending the production of a true knifeedge being solved by making a very narrow bevel on the front of the quartz plate and thereby producing a jaw with an angle of 90°. The bevelled edge is quite opaque in consequence of refraction and t o prevent light passing t'hrough the flat part of the plate the plane surface of the quartz was coated with gold by cathode deposition. The most striking result derived from the spectral examination of the thirty aerolites is the similarity in composition and the small number of elements which are present. Making due allowance for differences in the photographic activity of the elements in their arc spectra it is found that only ten of the known elements are present. These elements are iron chromium magnesium nickel silicon sodium manganese potassium aluminium and cdciuin and of these the first four only are present in quantity.Excepting the results for three aerolites it is found that the relative proportions of the several elements are approximately the! same in all. This suggests that the aerolites have a common origin in the disruption of some stellar body for which the process of cosmical evolution is complete. The siderites would appear to have a different origin or may possibly have formed the solid nucleus or core from which the chromium and other elements have been separated leaving the magnetic elements iron and nickel as a residue in the familiar ferro- nickel meteorites.H. M. D. Hydrogen and Calomel Electrodes. GILBERT N. LEWIS THOMAS B. BRIGHTON and REUBEN L. SEBASTIAN (J. Amer. Chem. Soc. 1917 39 2245-2261. C0mpar.e Lewis and Randall A. 1914 ii 802).-The resultx of a number of investigations on (i) the poten- tial of the hydrogen electrode in solutions of hydrochloric acid and VOL. CXIV. ii. 3ii. 26 ABSTRACTS OF CHEMICAL PAPERS. potassium hydroxide of various concentrations (ii) the dissociation constant of water (iii) the potential of calomel and silver chloride electrodes in solutions of potassium chloride and hydrochloric acid (iv) methods of establishing definite and reproducible potentials at' the boundaries between solutions and (v) on improvements in the experimental technique of such deterniinations are recorded a t some length.An electrolytic hydrogen generator which supplies a continuous stream of pure dry hydrogen I s described. Electrodes of gold coated with a layer of iridium are recommended as the most suitable for measuring hydrogen ion potentials since they very rapidly acquire the correct potential and then remain constant. Pieces of apparatus are described in which the hydrogen calomel and silver chloride electrodes are most conveniently and accurately built up. A device for maintaining a constant and easily repro- ducible surface of contact betwefen two liquids is also described. All measurements were made a t 25O and the following results each the mean of many experiment8 are given in the paper 1. Hg,HgCl,KCl O*lMI\N.E.; e = - 0.0529 volt. 2. Hg,HgCl,HCl 0.12MflKCl O.lM,HgCl,Hg; e = 0.0278 volt. 3. Ag,AgCl,HC1 O-liMIIKCl 0*1M AgC1,Ag J e =0*0278 volt. 4. Ag,AgCl,HCl O.OlM(IMC1 O*OlM AgC1,Ag ; e =0*0272 volt. The values of the E.N.F. in 2 3 and 4 afford very good con- firmation of the validity of the formula of Lewis and Sargent (A. 1909 ii 369) for calculating the potential difference between liquid surf aces. 5. H,,HCl 0*1M HgC1,Hg; e=0*3989 volt. 6 . H,,HCl O*lXlIK@l 0*1M HgC1,Hg; e=0'4267 volt. The value 0.4267 found for the Combination 6 can be obtained by calculation from the experimental values of combinations 5 and 2. If this value is combined with that obtained from combination 8 the value of the combination 9 can be calculated. 8. Hg,HgCl,HCl O.OlMIIKC1 O*OlM 13gCl,Hg ; e =0*0272 volt.9. H,,HCl O*OlMIIKCl 0*01M HgC1,Hg; e = 0'5377 volt The difference between the E.M.F. of cells 5 and 7 that is 0'1116 volt multiplied by F' (23074) gives the free energy of dilution of hydrochloric acid which equals 2573 cals. From this value the degree of ionisation of 0.1M 0*03M and 0.01M potassium chloride is found t o be respectively a=0*780 0.865 and 0.930. Making use of the foregoing potential values the value of the E.M.F. of the normal calomel electrode is calculated in terms of the value of the normal hydrogen electrode. The following values are obtained 7. H,,HCl O'OlM HgC1,Hg; e=0*5105 volt. ( a ) Hg,HgCl,HCl O'lM{(KCl O*lM HgC1,Rg ; e = 0*0012 volt. ( C ) Hz,B*(Jf)]\AT.Bo; e=0*2828 volt. ( b ) H,,H'(M)IIHCl 0.01M H,; e = -0.0644 volt.GENERAL AND PHYSICAL CHEMISTRY. ii 27 I n all cases (a) ( b ) and (c) the contact potential is eliminated. Consequently if the potential of the normal hydrogen electrode is take11 as zero the potential of the normal calomel electrode is - 0.2828 volt.10. H,,KOH O.liM1IKCl 0*1M HgC1,Hg; e = 1.0833 volts. 11. H,,KOH 0-OlMIIKCl 0*01M HgC1,Hg; e = 1.0820 volts. The dissociation const'ant of water is calculated from the hypo- thetical combination H,,OH'(ilii)llH'(nl)H,; e = 0.8278 volt and the value Kw=1-012 x 10-14 obtained. It is shown that the values of the E.M.F. obtained when the gas pressure is changed do not vary more than 0~00001 volt from the values calculated from the thermodynamic equation. J. F. S. Free Energy of Hydrochloric Acid in Aqueous Solution.11. ARTHUR A. NOYES and JAMES H. ELLIS (J. Amer. Chem. Soc. 1917 39 2532-2544. Compare A. 1916 ii 369).-In continuatioil o i previous msasurements of the E.X.P. of cells of the type II,l HC1 I HgCl I Hg the authors have replaced the calomel electrode by a silver chloride electrode with the object of obtaining more accurate data for acid solutions of low concentration. Data are recorded for solutions varying in concentration from 0.3 to 0*001N a t 1 5 O 25O and 35O. The changes in the free energy and total energy attending the transfer of one gram-molecule of hydrogen chloride from solutions of varying concentration to a 0' IN-solution are calculated from the data and it is inferred that hydrochloric acid is by no means completely ionised in 0*003N-solution.On the assumption that the ionic activity and the ionic comeu- tration can be regarded as equal in the case of this dilute solution the authors have recalculated the activity coefficients for hydro- chloric acid in solutions varying in concentration from 0-003 t o 4.5N. AS before (loc. cit.) these activity coefficients are found to diverge from the conductivity ratio h / A by about 10% in the case of a O.1N-solution. The calculated activity coefficients diminish with increase in the concentration of the acid UP to 0 . 5 ~ but increase rapidly as the concentration of the acid is further increased. H. 11. D. Potential of the Bromine Electrode Free Energy of Dilution of Hydrogen Bromide Distribution of Bromine between Several Phases. GILBERT N. LEWIS and HYMAN STORCH ( J .Arner. Chem. SOC. 1917 39 2544-2554).-A platiiium iridium electrode immersed in a solution of potassium bromide or hydrobromic acid containing free bromine has been used in the determination of the potential of the bromine electrode by measurements of the E.M.F. of the cells obtained by combina- tion of this with the calomel or the hydrogen electrode. The acid cell affords the more trustworthy results and the value of the lnomiiie potential for a solution containing bromine and bromide ion in inolar concentration against the normal hydrogen electrode is found to be - 1.0872 volts. 3-2ii. 28 ABSTRACTS 03’ CHEMICAL PAPERS. By measuring the E.M.F. of the cell H,/HBrIAgBrIAg for HBr concentrations equal t o 0.01 0.03 and 0*1N it has been found that the ionic activity coefficients are very nearly equal t o those previously found for HC1 a t the same concentrations.The determination of the ratio of distribution of bromine between carbon tetrachloride and aqueous solutions of 0*001N- and 0.1N- hydrobromic acid has shown that the constantl K = [HBr,] /[HBr][Er,] has nearly the same value as the constant for a solution in which the hydrobromic acid is replaced by potlassium bromide. By passing a current of dry air through solutions of bromine in carbon tetrachloride it has been found that the vapour pressure of the bromine is proportional to the concentration of the solution when this is measured in terms of molar fractions. H. M. D. Ionisation and Polymerisation in Cadmium Iodide solutions. It. G. VAN NAME and W.C. BROWN (Amer. J. Sci. 1917 [iv] 44 453-468. Compare A. 1917 ii 455).-In the further investigation of the constitution of cadmium iodide solu- tions measurements have been made of the E.M.P. of cells in which iodine electrodes are in contact with iodine-cadmium iodide solutions and also (of the freezing p i n t s of solutions containing cadmium iodide and varying proportions of iodine. The freezing-point data show that the freezing point of a cadmium iodide solution is depressed to the extent of about 1.4O per mol. of added iodine. This lowering is very nearly the same for solutions in which the cadmium iodide concentration is varied considerably. The facts point to the existence of polymerised mole- cules in considerable quantity. From the E.M.P. data it) is possible to calculats the iodine ion concentration in iodine-cadmium iodide solutions and by extra- polation to zero iodine concentration to obtain the iodine ion con- centration for pure solutions of cadmium iodide.For the niore dilute cadmium iodide solutions examined (0.01 and 0.125 molar) the data are in agreement with the assumption that complex mole- cules are present but the behaviour of the stronger solutions does not appear to be compatible with this hypothesis. The assumption that complex molecules of the type (CdI,) are the only complex molecules formed is found to bs insufficient t o reconcile the observations which have been made according t o the distribution freezing-point and E.M.F. methods. H. M. D. A Comparison of the Activities of Two Typical Electrolytes. G.A. LISHART ( J . Amer. C’hem. SOC. 1917 39 2601-2605).-Measurements of the E.M.F. of cells of the type H2 I HCI 1 HgCl I Hg have been made for solutions containing from 0.01 t o 16.0 mols. of hydrogen chloride in 1000 grams of water. Prom the results the ionic activities are calculated and compared with the .corresponding values for potassium chloride. On the assumption that these thermodynamic quantities afford a measureCIENERAL AND PHYSICAL CHEMISTRY. ii. 29 of the degree of ionisation of the two electrolytes it is found that there is a considerable divergence between the degrees of ionisation even in dilute solution whilst in concentrated solutions the divergence is enormous. Specific Heats and Heats of Fusion of Triphenylmethane Anthraquinone and Anthracene.JOEL H. HILDEBRAND (MISS) ALICE D. DUSCHAK A. H. FOSTER and C. W. BEEBE ( J . Amer. Chem. Soc. 1917 39 2293-2297).-The specific heat and latent heat of fusion of triphenylmethane anthraquinone and arithracene have been determined in a calorimeter similar to that described by Lewis and Randall (A. 1911 ii 371). The specific heats were determined over several temperature ranges. The materials were contained in vessels of quartz glass or " pyrex " glass and consequently the specific heat of these substances had to be determined. The following values were obtained pyrex glass s = 0.174 + 0.00036t ; quartz glass mean value over the range 20-320° s = 0.2161 ; triphenylmethane solid s= 0.186 + 0*00277t liquid s = 0.479 ; anthraquinone solid s = 0.258 + Om0007t liquid s = 0.66 ; anthracene solid s = 0.280 + 0*0007t liquid s= 0.509.The following heats of fusion were also obtained triphenyImethane 17.8 cal.; anthraquinone 37.4 cal.; anthracene 38.7 cal. It is pointed out that the specific heat equation for triphenylmethane is not trustworthy for extrapolation to lower temperatures as the range of temperature from which i t was obtained was so small (20-60°) and it is also suggested that the temperature coefficient of the specific heat is much larger than would be expected. H. If. D. J. P. S. The Entropy of the Elements and the Third Law of Thermodynamics. GILBERT N. LEWIS and G. E. GIBSOX (c7. Amer. Chem. Soc. 191 7 39 2554-2581).-A theoretkal paper in which the authors have calculated the entropies of the elements and applied the results in testing the theorem of Nernst which may be regarded as equivalent to the statement that the entropy of every substance is zero a t the absolute zero of temperature.On the assumption that the entropy of a substance is known at one temperature the entropy a t any other temperature can be calcu- lated if the specific heat' is known for the interval of temperature concerned. It i= shown that' the entropy may be calculated by a qraphical method which does not necessibate any assumption in regard t o the exact form of the heat capacity equation. The calcu- lated atomic entropies show with respect to atomic weight or atomic number the 9ame kind of periodicity which characterises certain other properties of the elements. According to the equation AF-AH= - TLS in which AF is the increase in free energy A H the increase in total energy and AS the increase in entropy for any isothermal change i t is possible to calculate the free energy of formation of any compound from its elemmts i f tlhe entropies of the compound and of the elements ail({ii.30 ABSTRACTS OF CHEMICAL PAPERS. the heat of formation of the compound are known. Conversely the entropy change associated with the formation of a compound from its elements can be calculated from the equation if the changes in total and free energy are known The entropy differences thus calculated for a number of com- pound substances are found t o agree satisfactorily with those which are derived from the atomic and molecular entropies calculated according to the method referred t o above in which it is assumed that the entropies of the elements and compounds are zero at th0 absolute zero of temperature.This agreement is considered t o afford new support for the so- called third law of thermodynamics. H. M. D. Determination of Boiling Points in Capillary Tubes. FRIEDRICH EMICH (Mo?zatsh. 1917 38 219-223) .-An open glass tube 7-8 cm. long of external diameter 0*6-1*2 mm. and with B wall 0.1 mm. thick is drawn out at' one end to a fine capillary approximately 2 cm. long and of 0.05-0.1 rnm. diameter. The end of the capillary is immersed in the liquid to be examined a,nd when about half a cubic millimetre has entered the tip is sealed by contlact with a flame. I f this operation is successful the capillary will have a minute bubble a t the extreme end covered by a liquid plug nearly 1 millimetre in length The tube is attached to a thermometer and warmed in a bath in which the heating liquid is 4-5 cm.deep. As the temperature is raised the plug of liquid ascends the capillary and the In. p. is registered when the plug reaches the level of the surface of the heating liquid outside. The method is naturally restricted t o pure substances. D. F. T. An EEcient Apparatus for Fractional Distillation under Diminished Pressure. WILLIAM A. NOYES and GLENN S. SKINNER (t7. Amer. Chem. SOC. 1917 39 2718-2720).-A modified Claisen flask is used. The side-tube of the flask is bent upwards and fused on to a simple fractionating cohmn and into the side of the neck of the flask is fused a separating funnel.The flask can thus be used for large or small fractions by repidating the flow of liquid from the separat'ing funnel and successive fractions may be intro- duced without losing the vacuum. T I T . G. Studies in Catalysis. VIII. Thermochemical Data and the Quantum Theory. High Temperature Reactions. WILLIAM CUDMORE MCCULLAGH LEWIS (T. 1917 131 1086-1102. Compare ibid. 457).-According t o the radiation theory and the quantum hypothesis the heat of a reaction Q is given by the equa- tion Q=Nh(Zv,-Xv,) in which P is the Avogndro constant h the Planck constant Z v the sum of the critical frequencies of the react- ing substances and 2v2 the corresponding quantity for the resultant products. This relation has been previously deduced by Haber (Rer.Beut. ph?ysikrrZ. Ges. 1911 13 11171 who calculated tlheQENERAL AND PHYSICAL CHEMISTRY. ii. 31 critical frequencies of substances for which the requisite data were not available by means of the semi-empirical relation vV/vy= J.M/m in which vv is the characteristic ultra-violet frequency vl. the characteristic ultra-red frequency in terms of which the specific heat may be represented M the molecular weight of the substance and m the mass of an electron. The use of this equation involves considerable uncertainty in regard t o 171 aiid in Raber’s treatment of the problem in its application to the formation of a salt such as sodium chloride from its elements the quantity 21)~ is arbitrarily made equal to half the sum of the critical frequencies of the elements instead of the entire sum.By making the assumption that the ultra-violet quantuni breaks the bond between two adjacent atoms which are both thereby rendered chemically active i t follows that one quantum character- istic of sodium plus one quantum characteristic of chlorine will suffice to bring about the change represented by 2Na + 2@1= 2NaCl. Hence 2Nhvxac - Nh(v + vC,) should be equal to the heat of formation of two gram-molecules of sodium chloride. This relation is identical with that which follows from the introduction of the arbitrary assumption which is characteristic of Haber’s method of treatment. The application of the equation to the calculation of the heat of formation of sodium chloride may be briefly indicated. From the wave-length (A = 52 p) of the characteristic infra-red band v,.=0*0577 x 1014. By means of the square root relation (see above) v?) = 19.27 x 1014 from which the critical increment Nh:~N;IC = 182,290 ca!. Similarly the sum of the critical increments for 1 gram atom of sodium and 1 gram atom of chlorine is found t o be 85,000 cal. The lieat of formation of the salt is therefore 182,290-85,000= 97,290 cal. which agrees with the observed value 97,800 cal. Similar calculations have heen made in respect of other sub- stances fcr which the requisite data are available and the results when compared with the observed heats of reaction show a degrea of apreement which supports the validity of the equation connect- ing the heat of reaction aiid the critical freqnencies. Thermochemical Studies.DANTEL LAGERLOF (J. pr. Chem. 1917 [iil. 96 26-34).-A theoretical paper in extension of the earlier mathematical discussion (A. 1904 ii 382 605 ; 1905 ii 76 677) of the heat. of formation of carbon compounds the thermal effect of the intramolecular linkings being especially con- sidered from the author’s point of view. -__ H. M. D. D. F. T. Thermochemical Studies. The Constitution of Benzene and of some Condensed Aromatic Hydrocarbons con- sidered from the Thermochemical Point of View. DANIEL LAGERLOF (1. pr. Chew. 1917. rii] 96 35-49).-The relative stability of the cyclic hydrocarbons containing rings larger than cyclopentane as compared with the smaller rings such as cyclo- propane is attributed to the strain in reducing the aagle betweenii. 32 ABSTRACTS OF CHEMICAL PAPERS.the carbon valencies in the latter causing an endothermic effect whereas in the author's view the enlarging of the valency angle in the format'ion of hexatomic and bigger rings produces an exothermic effect if the ring is a plane one. Mathematical argu- inents are adduced in favour of this theory and the annexed formu12 are suggested for benzene naphthalene anthracene and phen- anthrene respectively. D. F. T. The Standard Unit in the Thermochemistry of Organic Compounds. W. SWIENTOSLAWSKI ( J . Amer. Chem. SOC. 1917 39 2595-2600).-The values obtained for the heats of combustion of naphthalene benzoic acid and sucrose in recent measurements are compared and discussed. I n terms of the 15O calorie the most probable values for the heat' of combustion of 1 gram of substance weighed in air are naphthalene 9612 Cal.; benzoic acid 6311 Cal.; sucrose 3945 Cal.To obtain satisfactory agreement in thermochemical data it is recommendeld that the heat capacity of calorimetric bombs should be determined by a standard method involving the use of a standard combustible substance. The question whether the heat of combus- tion is t o be expressed in terms of kilo-joules or calories should be determined by the International Congress. Until the standard substance has been decided on the calibration of calorimetric bombs should be based on one or other of the above values for the heats of combustion of naphthalene benzoic acid or sucrose. 33. M. D. Improved Form of Pyknometer. MARKS NAIDLE ( J . Amer. Cham. Soc. 1917 39 2357-2388).-A modification in the cap of tli3# side arm of a pyknometer to provide f o r any liquid which may be driven'out of the instrument by expansion during the weiqhing.J. F. S. Improved Victor Meyer Vapour Density Apparatus. D. A. MACINNES and R. G . KREILING (J. Arner. Chem. SOC. 1917 39 2360-2354).-1mpi-ovements to the Victor Meyer vapour density apparatus in connexion (i) with the means of introducing the substance (ii) with the vaporisation tube are described. It is pointed out thatl when the cork of the usual form of the apparatus is withdrawn t o allow of the admission of the substance under investigation there1 is a certain amount of cooling of the air inside the tube also there may be a certain amount! of spirting of the liquid on to the walls of the vaporisation tube.Both these effects will produce! errors. The authors suggest a means of introducing the substance a t the bottom of the bulb and a t the temperature ofGENERAL AND PHYSICAL CHEMISTRY. ii. 33 the vaporisation tube. A long glass tube reaching almost to the bottom of the vaporisation tube is fitted by means of a rubber stopper in the neck of the apparatus. A brass rod fitted with a hook a t its lower end passes down this tube and is made air-tight a t the upper end by means of a rubber tube. The substance under investigation is placed in a small bulb which has a long capillary neck (2-3 cm.) bent twice a t right angles. This is placed on the brass hook and the rod drawn up until the bulb neck just touches the enclosing glass tube. When the temperature of the vaporisa- tion vessel is constant the bulb is broken by drawing the brass rod sIightly further u p the tube.It is stated that the air in the ordinary vaporisation tube not being all a t the same temperature is the cause of niany errors. To obviate theHe the authors suggest a modified form of vaporisation vessel. This consists of a large test-tube 25 cm. long and 5 cni. diameter which carries a rubber stopper through which passes a capillary delivery tube and a straight tube 28 cm. 1on.q and 1.5 cm. diameter. The latter tube is placed centrally reaches almost t o the bottom of the outer vessel and carries the breaking apparatus described above. The whole apparatus is placed in a large boiling tube in the usual manner. It is to be pointed out that with thiq angaratus owing to the sudden rush of air when the tube of.materis1 is broken t.lie usual eudiometer and pneumatic trough are use- lees and must be replaced bv a gas burette.Trial experiments 2re described with numerical details €or bromine ethyl alcohol a n d diethpl ether. The resdts are in every way quite good. J . 5'. S. Convergence of the Liquid and Solid Volume Curves to Absolute Zero. GERVATSE LE BAS (Chem. Nms 1917 116 307-308).-1t is shomii t1mtm in general the solid and liquid ciirves c0nverg.e to absolute zero. This applies to types of substances where the liquid volume curve is stleeper than the solid curve where the volume of the resiiltant solid is greater than that of the liquid. w. P. s. The Relation between Temperature and Molecular Surface Energy for Liquids between -80" and 1650O. F.M. JAEGER (Zeitsch. anorg. C h ~ i n . 1917 101 1-214).-The author has determined the surface tension and molecular surface energy of about 200 organic iiquids between -80° and 250° and of about 50 inorganic substances in the molten condition between 300° and 1650O. The method employed was to determine the burst- ing pressure of bubbles of the liquid blown on the end of a capillary tube of known diameter just' immersed in the liquid. For high- temperature work the substance under examiliation was melted in a veFsel of platinum or platinum-rhodium heated in a resistance furnace the capillary tube being of the same material. The coni- plicated nppnratus used is described and illustrated in great detail.ii.34 ABSTRACTS OF CHEMICAL PAPERS. In the specially designed manometer normal octane was used in contact with mercury; it is strongly recommended as an ideal liquid for this purpose. For each of the substances examined a table is given in which is detailed for each temperature atl which observations were made (1) the surface tension x in ergs per square centimetre calculated from the equation x=r31/2 where T is the1 radius of the capillary and H is the bursting pressure in dynes; (2) the density d of the liquid; (3) the molecular surface energy p in ergs per squars centi- metre where p,=x(M/D)$; (4) the specific cohesion A2=2x/(g. d); (5) the quantity (A2M)/T where T is the absolute temperature of the melting point; (6) the temperature coefficient of the molecular surface energy dp/dt.Every substance examined was carefully purified and its density determined at' different temperatures special methods being developed for the high-temperature measurements. For many of the substances x-t and p-8 curves are given. It has been demonstra€ed by Eotvijs from van der Waals's law of corresponding states that for normal non-associated liquids dp/dt should be a constant=2*25 ergs per lo whilst for associated liquids the temperature coefficient should be smaller. Further it can be shown thermodynamically that if dpldt is a constant the specific beat of the surface layer must be the same as t h a t of the bulk of the liquid. The great number of p-t curves now examined illustrates well the constitutive character of molecular surface energy.The curves are rarely straight lines tho value of the temperature coefficient in the case of organic liquids generally fzlling but sometimes increas- ing with rising temperature. I n general in a series of related substances such as alcohols fatty acids or esters a t a given temperature the value of p increases with the molecular weight. The introduction of increasing quantities of halosen into hydro- carbons also increases the molecular surf ace energy. Isomeric sub- stances such as ethylene dicliloride and ethylidene chloride show wide differences. The value of dpld't is fairly constant for a series of related substances but marked exceptions sometimes occw ; thus formic acid has an exceptionally low value. I n the primary secondary and tertiary aliphatic amines the values of ,u and CJp/dt increase very markedly with increasing carbon content the lower members of the series haviiig ahnorr?n!ly low temperature coefficients.Of isomeric primary amines those with straiqht carbon chains have greater molecular surface enerqy than those with branched chains. Unsaturated substances such as allylamine Lave higher values of ,u than the corresponding saturated compounds. Formamide has an exceptionally low temperature coefficient 0.89 erg per lo similar to t h a t of water. This fact is probably to be associated with its high dissocizting power. The unsaturated character of aromatic compounds is accompanied by increased values of p. The halogenated compounds show in- creasing values of p with increasinq 'molecular weiqht.Position isomerides show marked differences ; for example of the three nitro-GENERAL AND PELYSICAL CHEMISTRY. ii. 36 phenols the para-compound has the greatest and the ortho-com- pound the least molecular surface energy. I n the nitroanisales the differences are much less marked probably because here there is no mobile hydrogen atom. The molecular surface energy of aniline and its homologues is much higher than that of any of the primary ali- phatic smines up to heptylamine. The introduction of halogen or nitro-groups into aniline increases the value of p as in the hydro- carbons. The surface energy relationships of many other aromatic compounds are discussed. Specially interesting are tlie p-t curves for such substances as p-azosyanisole p-azoxyphenetole and anisaldazine which form anisotropic liquids (liquid crystals).The curve consists of two distinct portions with a sharp minimum where the liquid passes from the anisotropic t o the normal form. The temperature coefficient of the anisotropic liquid is always greater than that of the normal liquid a fact which is contrary to Eotvgs’s conclusion that a lower temperature coefficient indicates a greater degree of molecul~r association. It is concluded that in substances of this class very complex and little understood changes are brought about by heat. The relationships among the haloids of phosphorus arsenic antimony and bismuth are in general similar to those among organic halogen compounds tlie values of x and p increasing with the molecular weight whilst the magnitude of d p l d t is more or less normal.Quite different however are the haloicis of the alkali metals lit,hium sodium potassium rubidium and czesium. For the same metal. the surface tension x of the molten salt! decreases with increasing atomic weight of the halogen from fluorine t o iodine and also decreases for the same halogen with increasing atomic weight of the metal. The values of p vary in an irregular manner whilst du./df is in all cases abnormally small. Other salts investi- gated include sulphates nitrates borates molybdates and tanestates of the alkali metals. It is concluded that a t high temperatures the law of correspond- ing states cznnot hold for mclten salts which are probably highly ionised and t h a t Eijtviis’s rule based on the va,lidity of this assump tion that a low value of dp/dt indicates a high degree of associa- tion in the liquid is therefore invalid.Also since d p / d t is bv no m2am constant f o r organic or inorganic liquids the1 specific hent of the surface larer must be different from that of the rest of the liquid. and the surface energy must be a t least in part of a kinetic nature. The author has investiqated t h e empirical rule discovered by Walden that for many non-acsccixted liquids the quot.ieEt obtained 13-7 dividinn the niolocular cohesion by the alxolute temperature of (n) the n?slt,inc point or ( 6 ) the boilinq point is a constant in the case of ( a ) 3.65 and of ( h ) 1.15 approx. The vaIuw of these two I f constants ” have been calculated pnd tabulated by the author for about 200 different substances which are divided into four groups according to the manner in which either value varies fromii.36 ABSTRACTS OF CHEMICAL PAPERS. the mean.. The rule is evidently only approximate and many variations occur which cannot be explained on the ground of mole- cular association. The greatest irregularities occur however among inorganic salts. E. H. R. Solubility and Internal Pressure. JOEL H. HILDEBRAND ( J . Amer. Clzem. SOC. 1917 39 2297-2331. Conipare A. 1916 ii 518).-Where Raoult's law is obeyed by a solution the solubility of the solid a t the absollite temperature T may be calculated by means of the expression log N = - LTT7,/4.58(T7 - T) where N is the solubility expressed in terms of molecular fractions L is the molecular heat' of fusion and T the melting point in absolute degrees.The author has calculated the solubility of anthracene anthraquinone p-dibromobenzene phenanthrene and tripheiiyl- methane a t 2 5 O by means of the formula and compared these values with the experimentally determined solubilities (see this vol. i 62) in some eight solvents. Iodine has been treated similarly. The divergence of the solubility from the calculated value is considered along with the interns1 pressure of the solvent and it is shown in the case of anthracene which has practically the calculated solu- bility in carhon disnlphide t h a t its solubility decreases with decreasing internal pressure for non-polar liquids. I n the case of alcohol a polar liquid the divergence from the calculated solubility is much greater a fact which agrees with the third rule previousIy stated (ZOC.c i t . ) . Formation of Additive Compounds in Aqueous Solutions. Stability of Hydrates and the Determination of Hydration in Solution. JAMES KENDALL JAXES ELIOT BOOGE arid JAJIES C ANDREWS ( J . A mw. C12~n2. ,COG. 1917 39 2303-2323).-The results of previous work on the formation of additive componnds are summarised and the general rules established in this work are recapitulated and extended to aqueous solution (A. 1914 i 858 1069; 1915 i 16 80; 1916 i 599 707). Since water can function both as a weak acid and a weak base the extent OF hydration in aqueous solutions should be found to increase with the increasine acidity or basicity of the solute. The known hydrates of acids and bases are reviewed in the paper and it is shown t h a t only the stronger acids and bases yield compounds with water which are capable of isolation.A number of freezing-point determinations with solutions of varying concentrations of the following acids acetic P-hydroxypropionic a-hydroxypropionic citric d-tartaric hydrofluoric phosphoric and hydrochloric have been carried out. The results in all cases conform exactly with the abov'e-mentioned prediction. A critical discussion is given of the factors which must be taken into consideration in the determination of hydration in solution by the freezing-point method. The question of the hydra- tion of salts is treated in a preliininary manner anti i t is shown that the hydration follows the order of the scheme Ce<Rb<T<<NHf<Na<T.i J.F. S. and NO < C1< Rr < I. J. F. s.GENERAL AND PHYSICAL CIiEMlSTRY. ii. 37 Mechanism of the Ionisation Process. J A 31 F:S K ENDALL aiid JAMES ELIOT BOOGE (,I. Rnzer. Chent. Soc. 1917 39 2323-2333).-The results of a number of papers by the authors (see preceding abstract) have indicated an intimate and general connexion between ionisation and the formation of compounds in solution. I n the present paper the authors advance the hypothesis that ionisation is preceded by combination between solvent and solute 2nd is indeed a consequence of such combination. This point of view combines the current ionic and hydrate' hypotheses re- f erring conductivity in solutions t o the dissociation of solutesolvent complexes into radicles of opposite charge.The actual mechanism of the ionisation process under this assumption with its relation t o phenomena such as unsaturation association and high dielectric constant is briefly discussed. It is shown that compound forma- tion between solvent and solute may be postulated in all conduct- ing solutions and that the distinction still commonly retained between the two components is arbitrary and misleading. The general evidence in favour of the hypothesis is given in a pre- liminary form attention being centred on a few fundavneiital points only. J. F. S. Soap Bubbles as Models of Crystal Structure. ill. J. MARSHALL ( J . Amer. Chent. SOC. 1917 39 2386-2387).-1t is shown that when small soap bubbles of uniform size are produced on the surface of a soap solution they form a symmetrical network which is in reality the simple face-centred lattice as found in crystals of pure metals.These bubble aggregates can readily be produced and projected on the screen and so serve to show causes of crystal structure and the method of building up of crystals. The best effects are produced by using a solution of sodium oleate to which glycerol has been added and blowing the bubbles by means of a glass tube which has been constricted to 1 nim. diameter by drawing and then further constricted t o a very fine tip by allow- ing the walls of the 1 mm. tube to fall together in a smoky flame. The jet should be at right angles t o the surface of the soap solutioii when the bubbles are blown. J. F. S. Formation of Crystals in Gels.HARRY N. HOLMIW ( J . Physical Chem. 1917 21 709-733).-The influence of silicic acid gels on the forination of crystals has been examined by experiments in which one of two reacting soluble substances was added t o a solution of silicic acid which was then allowed to set. The second substance dissolved in water to give a solution having a greater osmotic pressure than the jelly was then brought into contact with the upper surface of the jelly and slow diffusion allowed to take place. If an insoluble substance is produced by the reaction this forms within the jelly and the slow diffusion process leads to the formation of large well-developed crystals. Perfectly f orined tetra- hedral crystals of copper may for instance be obtained by the diffusion of hydroxylamine hydrochloride into a silicic acid gel con-E.38 ABSTRACTS OE' CHEMICAL PAPERS. taining copper sulphate. Other substances obtained in crystalline form by this method were silver dichromate gold lead iodide mercuric iodide basic mercuric chloride silver sulphate silver acetate and basic lead chromate. The capillarity associated with the gel structure is supposed t o be partly responsible for the observed crystal growth and a similar influence is brought into play when the fine-grained precipitation membrane begins to be formed. I n support of the theory that the capillary diffusion is the chief factor in the phenomenon i t has been observed that well-formed crystals may be obtained by allowing slow diffusion t o take place through flowers of sulphur barium sulphate or alundum.H. M. D. Properties of Mixed Liquids. 111. Law of Mixtures. I. J. LIVINGSTON R. MORGAN and M ~ R Y A. GRIGGS (J. Amer. Chein. Soc. 1917 39 2261-2275. Compare A. 1916 ii 224 296).- With the object of testing the validity or otherwise of the simple law of mixtures the surface tension of a number of homogeneous mixtures has been determined by the drop-weight method a t two temperatures in each case. The lower temperature was loo or 1 5 O and the higher temperature 40°. The folIowing mixtures in a series of compositions were measured ( a ) Binary mixtures benzene- toluene benzene-ethyl propionate benzene-chlorobeiizene benzene- methyl butyrate benzene-propyl acetate benzene-acetone toluene- ethyl propionate toluene-chlorobenzene toluene-methyl propionate toluene-ethyl formate acetone-chlorobenzene chlorobenzene-ethyl propionate ethyl lactatepropyl acetate chlorobenzene-methyl butyrate amyl p-phenylpropionate-methyl propionate and acetone- propyl acetate.( b ) Teriiary mixtures benzene-tolueneethyl propionate benzenetoluene-chlorobenzene benzenetoluene- methyl propionate and benzene-toluene-acetone. ( c ) Quaternary mixtures benzene-toluene-ethyl propionate-chlorobenzene benz- ene-t oluene-meth yl pr opionat e-et hyl lactate and benzene-t oluene- methyl butyrate-propyl acetate. ( d ) Quinary mixture benzene- toluene-methyl butyrate-propyl acetate-methyl propionate It is shown thatl ten of the above-mentioned mixtures follow rigidly the law of mixtures in the form = Z,P,+l,P,+ etc. (where the summation of the relative weights I Zb etc.is equal to unity. Of these mixtures six were of two constituents two of three con- stituents one of four constituents and one of five constituents. Where variations appear the observed value is invariably less than that calculated from the law. These deviations increase in magni- tude with increased temperature and are always at a maximum at both temperatures for that mixture which contains equal weights of the constituents. Although the deviations might be due t o the magnibude of the difference in the surface tension values of the constituents when pure the effect is probably negligible and merges into the more important' factor-the nature of the constituent. Ail example of the latter is chlorobenzene which renders every rn ixture in which it is present abnormal.The deviation of a complex mix-GENERAL AND PHYSICAL CHEMISTRY. ii. 39 ture is not a summation of the deviations of the pairs of liquids of which it could be made but is of the same order as these. It is further shown that chemical interaction for binary mixtures could not be the cause of the maximum deviation invariably found a t a composition of 50% by weight of the two constituenh whereas this behaviour is shown to be exactly what might be expected if the one liquid by its simple physical presence influenced the value of the property of the other and the conclusion is consequently drawn that the mixture law considered is a rigid law provided no chemical action takes place between the constituents and neither liquid influences the value of the property of the other.J. F. S. Properties of Mixed Liquids. IV. Law of Mixtures. 11. J. LIVINGSTON R. MORGAN and ANDREW J. SCARLETT jun. ( J . A naer. Clienz. SOC. 1917 39 2275-2293. Compare preceding abstract).-The surf ace tension of the following binary mixtures (i) water-acetone (ii) acetone-ethyl alcohol (iii) phenol-acetone (iv) phenol-ethyl alcohol (v) benzene-acetic acid (vi) benzene- ethyl alcohol (vii) benzene-methyl alcohol (viii) acetone-methyl alcohol (ix) ethyl alcohol-nikthyl alcohol and (x) benzene-phenol has been determined by the drop-weight method over a range of concentrations and temperatures. The curves representing the variation in surface tension with concentration are in general with- out maxima or minima but that of (v) shows a minimum whilst (ii) and.(viii) show maxima. The comparison of the experimental results with those calculated by nieans of the mixture law of Morgan and Griggs leads to the following observations which fall into three groups (a) the systems (i) (iii) (iv) (v) (vi) (vii) and (x) give values smaller than the calculated values; (6) systems (ii) and (viii) give values larger than the calculated values; (c) the remaining system (ix) gives a slight positive deviation a t OG no deviation a t 30G and a slight negative deviation at 45O. The position and magnitude of the maximum deviation from the mixture law found when the deviation is plotted against’ the con- centration of one constlituent divides the systems into two classes. I n one class the maximum deviation always very small is found €or a mixture containing 50% by weight of each constituent.The systems falling into this group are (ii) (viii) and (ix). The only explanation of this behaviour is that it is due to the physical effect of the one liquid on the other since an equal weight of the two constituents brings about the effect. Systems of the other class on the contrary exhibit a maximum deviation usually larpe and at some other concentration than 50% which corresponds always with some simple and even relation of the molecular weights of the constitueiits that is corresponds with a definite chemical formula. The cause of this according to the theory put forward by Denison (A. 1913 ii 30) is the actual production of a compound. The molecular compounds found to exist in the binary mixtures of liquids examined are COl!k2,10H,0 2PhOH,COMe PhOH,2EtOH C,H,,2CH,-C02H,ii.40' ABSTRACTS OF CHEMICAL PAPERS. 2C6H,,EtOH C6H6,MeOH and 4PhOH,3C&&. The existence of these compoands in solution is confirmed by density and vis- cosity measurements. The compound C,H6,2CH,*C0,H shown to exist in the system benzene-aoetic acid is particularly interest- ing when considered in the light of the results of other methods which lead to the conclusion that acetic acid is always polymerised into double molecules in benzene solution. These methods are such however its would fail to show a combination o€ the solvent with the polymerised solute even if it did exist; and hence the evidence found here is not only not inconsistent with other evidence but gives a wider point of view on the process which has been designated hitherto as a simple polymerisation System of Recording Rate of Chemical Reaction.JAMES W. MCBAIN (Chem. News 1917 116 315-316).-It is suggested that the usual expression for denoting the velocity constant of a reaction may be replaced by a number which has a direct physical significance. For instance it may be written k = 1 / t (remainder of thd expression) where k is the! present rate constant of the reaction and t is the time the reaction has proceeded or k t = (remainder of the expression). It is necessary to give the value of k and also the value of the unit of time (minutes or hours). The value of k is however always set a t unity and the unit of time is chosen accord- ingly; the equation then becomes t = (remainder of the expression). The chief advantage is that the proposed " unit of time" gives a direct idea of the rate of the reaction.J. F. S. w. P. s. Contact Catalysis. 111. WILDER D. BANCROFT (J. Physiccd Chem. 1917 21 734-775. Compare A. 1917 ii 566; this vol. ii 13).-A review of the literature relating to the action of poisons in contact catalytic reactions. The changes in over-voltage pro- duced by certain ions are supposed to be effects which are com- parable with retarded or inhibited contact catalytic reactions. n. M. n. Revision of Atomic Weights in 1916. E. MOLES ( J . Chinz. phys. 1917 15 433-469).-A review of $he work on the deter- mination of atomic weights published during 1916. Errors affecting the Determination of Atomic Weights.VI. Surface Actions as a Sourceof Errors in Weighing. PH. A. GUYE and E. MOLES (J. Chim. phys. 1917 15 360-404. Compare A. 1916 ii 385 386 432 445).-A further consideration of the errors involved in the accurate determination of equivalent weights in which the authors direct attention to the anomaly first pointed out by Hinrichs (compare A. 1893 ii 163 316; 1894 ii 276) that the value of the combining ratio is a function of the quantity of substance used in the determinations. It is considered that the available data afford clear evidence that such a relation does actually exist but the interpretation given by Hinrichs is considered to be unacceptable H. M. D.GfiNlCRAL ANI) 1'iIYSICAL CHEMISTRY. ii. 41 By reference t o data obtained in recent work 011 the deterniina- tion of atomic weights it is found that all series of measurements do not show the occurrence of such a connexion between the com- bining ratio and the quantity of substance operated on but that this is confined to series oi' determinations in which the quantit'ies of substance employed have been determined by weighing in air the reduction to a vacuum being effected by calculation.This suggests that the anomaly is due t o surface condensation of air water etc. and it is shown t h a t the curves which express the rela- tion between the experimental combining ratio and the weight of substance operated on can be satisfactorily accounted for on this hypothesis. The average relative deviation attributable t o this source of error is 1 in 20,000 but it.is sometimes as high as 1 in 10,000. H. M. D. Errors affecting the Determination of Atomic Weights. VII. Surface Actions as a Source of Errors in Weighing. PH. A. GUVE and E. MOLES ( J . Chini. ph~ys. 1917 15 405-432. Compare preceding abstract) .--Experiments have been made with silver in the form of a solid block and with finely powdered zinc oxide with the object of ascertaiiiiiig the magnitude of the errors which may be ascribed to the formation of a surface filin when these substances are weighed in the air. In the case of silver the error involved amounts t o 2 x 10-5 grain per gram of silver. This value is to be regarded as a minimum the actual error in practice depending on the humidity of the air in tlhe balance case on the nature of the surface of the metal and on other factors. The error attributable to surface condensation according t o the experi- inents with zinc oxide is of the order 0.2 t o 0.4 x 10-5 gram per gram of substance. It is shown that errors of this order of magnitude affect the value of the second decimal figure when the atoniic weight of the element under consideration is greater t,han 100. The errors in question should be eliniiiiated in atomic weight measurements by actually weighing the substances involved in a vacuuni. The possibility of making such weighings has been greatly increased as a result of recent improvements in the technique of various forms of micro- balance. H. M. D. Graphical Interpolation of Tabulated Data. HORACE G. DEMING ( J . Anacr. C k e m . SOC. 1917 39 2388-2392).-A method is described based on the principle of a triple parallel alignment chart' whereby the intersolated values required from data may be rapidly obtained by a graphic method. It is claimed for example that the adoption of this principle t o logarithm tables would reduce the amount' of space occupied by such tables to about 10% of that now necessary. .J F. S. VOL. cxiv. ii. 4

ISSN:0368-1769    

DOI:10.1039/CA9181405025

出版商:RSC    

年代:1918

数据来源: RSC

摘要:

ii. 42 ABSTRACTS OF CHEMICAL PAPERS. Inorganic Chemistry. Revision of the Atomic Weight of Bromine. Normal Density of Hydrogen Bromide Gas. CLARENCE KENWORTHY REIMAN ( J . Chim. phys. 1917 15 293-333).-A full account of work already published (compare A. 1917 ii 137 ZOO). El. M. D. Revision of the Atomic Weight of Bromine. Normal Density of Hydrogen Bromide Gas. WALLACE JENNINGS MURRAY ( J . Chim. phys. 1917 15 334-359).-A full account of work previously published (A. 1917 ii 201). Chemical Reactions in the Corona. I. Ozone Formation. F. 0. ANDEREGG ( J . Amer. Chem. SOC. 1917 39 2581-2595).- An account is given of some preliminary observations which have been made on the formation of ozone during the passage of a current of oxygen through a tube in which corona discharge is maintained.The results suggest that a condition of equilibrium is rapidly attained. It is hoped that the study of this and other reactions in the corona discharge will throw some light on the connexion betweeii ionisat'ion and chemical reaction. H. M. D. H. &I. D. Analytical Control of the Ammonia Oxidation Process. G. B. TAYLOR and J. D. DAVIS ( J . Ind. Eiig. CJiem. 1917 9 1106-1110).-1n the catalytic oxidation of ammonia by means of atmospheric oxygen for the production of nitric acid the following reactions t'ake place (1) 4NH3+ 50,=4NO +.6H,O . . . . (2) 4NH3 + 30 = ZN + 6H,O * . . and the possibility of the second reaction being produced by means of an intlermediate reaction 4NH,+6NO=5N,+6H20 . . . . . (3) was pointed o u t by Reinders and Cats (A.1912 ii 248). Evi- dence that tliis third reaction does take place under certain conditions has been obtained in the case of a badly con- st'ructed oxidiser in which irregular cooling of the catalyst was produced locally by currents of the burned gases. Samples taken from points near the cool places contained ammonia whereas in samples taken outeide the catalyst chamber the proportion of ammonia was low. It was probable that most of this ammonia passing such points was sulssequently ' burned " by the hot nitric. oxide. Effective working in a converter depends on maintaining conditions which promote reaction (1) a i d are unfavourdde t o reaction (2). [See further J . Soc. Chem. Ind. 1918 37 54~.1 C. A. M.INORGANIC CHEMISTRY. ii. 43 The Solubility of Silica.VICTOR LENHER and HENRY BALDWIN MERRILL ( J . Amer. Chem. SOC. 191'7 39 2630-2638).-The solu- bility of silica in wat,er and in aqueous solutions of hydrochloric and sulphuric acids of varying concentration has been measured at 35O and 90°. With gelatinous silica a condition of equilibrium is reached after a few hours or days but with ignited silica much longer periods are required for the attainment of saturation. The results seem to show that the solubilit'y of gelatinous silica is in- dependent of the method of preparation of the substance and that ignited silica will give solutions of the same concentration when the equilibrium condition is reached. The solubility increases with the temperature and a t a given temperature decreases with iiicrease in the concentration of the acid.Carbon dioxide has no measurable influence on the solubility of silica. The results are not only of interest in connexion with the estimation of silica but possess considerable geological significance. H. ng. D. Polysulphides of the Alkali Metals. 111. Solidifying Points of the Systems Sodium Monosulphide-Sulphur and Potassium Monosulphide-Sulphur . JOHN SMEATH THOMAB and ALEXANDER RULE (T. 1917 111 1063-1085. Compare T. 1914 105 177 2819).-The freezing-point curves for mixtures of sulphur with sodium monosulphide and potassium monosulphide derived from observations on the rate of cooling of the mixtures in a current of dry nitrogen show the existence of a complete series of compounds of the formula R,S where x is a whole number having the maximum value 5 in the sodium series and 6 in the potassium series.The members of the potassium series of compounds resemble closely the corresponding rubidium and czsium compounds (Biltz and Wilke-Dijrfurt A. 1905 ii 162; 1906 ii 283 611) but the sodium compounds differ from their analogues in appearance and properties. This difference is also shown in the comparative stabilities of compounds of corresponding composition and in the maximum combining power of the metals. The rate at which the polysulphides lose sulphur when heated in a steady stream of hydrogen at regularly increasing temperatures has also been examined. The results obtained indicate that the disulphides of both metals are very stable compounds from which sulphur can only be removed with difficulty a t 70C)-8OO0.This suggests that the polyysulphide molecules contain two atoms of sulphur which are combined differently from the remaining atoms of sulDhur. The disulphides are represented by the formula R-R*S*R and the higher p0lysii1phides by formnlp such as s s R.0 S* S R and .... . S R-S-S-R Molecular weight determinations by the boiling-point method in ethyl alcohol solution gave numbers less than those required by theformula &S,. These results favoui. t lie simple forinul,~ K,SZ as opposed to the doubled formula R,S suggested by Rloxani (T. 1900 77 753). The difference between the actual results and those required by the formula R,S are attributed t o ionisation. No evidence of intermediate compounds such as the ennea- sulphides (Bloxam loc.c i t . ) has been obtained in either series. H. M. D. Ammoniacal Copper-Mercury Derivatives. %. ANDERLINI (Gazsettn 1917 47 ii 171-176. Compare A. 1912 ii 764).- The conzpoz/nd CuHgBr,,4NH3 is obtained in dark blue crystals by mixing boiling solutions of ammoniacal cupric bromide and mercury bromide dissolved in potassium bromide. If this com- pound is dissolved in a warm solution of ammonium bromide and the solution treated with mercury bromide dissolved in potassium bromide free ammonia being present but not in excess the com- pound CuHg,Br,,4NH3 is obtained in bright blue scales or needles. R. V. S. Observations on the Rare Earths. IV. The Purification of Gadolinium. LOUIS JORDAK and B. S m r H HOPKISS (J. 14?ne1*. Chem. Soc. 1917 39 2614-2623).-The results of experiments are described in which the attempt has been made to separate gadolinium from rare earth mixtures by the fractional precipitation of the dimethyl phosphates bromates and glycollates.Fractionation of the dimethyl phosphates rapidly removes europium and samarium completely and gadolinium of considerable purity is obtained from the middle fractions. The terbium which is present in this material can be removed by fractionation of the bromates. The glycollate method rapidly removes samarium from gadolinium but has little effect' on the removal of terbium. The method recommended for the separation of gadolinium from rare earth mixtures is first to remove ceriuni by the bromate method and fractionally crystallise the residue. The less soluble fractions contain only europium samarium gadoIinium and neodymium which are converted into the dimethyl phosphates and again frac- tionated. The least sol~~ble fractions will then consist of high-grade gadolinium.Any remaining traces of samarium can be removed by precipitation with sodium glycollate. H. M. D. . Revision of the Atomic Weight of Samarium. Analysis of Samarium Chloride. 0. J. STEWART ant1 C. J a m s ( J . Anzey. Chem. Soc. 1917 39 2605-2614).-A fractionation method for the extraction of samarium from its admixtures with the other rare earth metals is described. The pure samarium oxide was Converted into the chloride SaCl,,GH,O which was dried finely powdered. and heated below looo until most of the water of crystallisation had been driven off. The temperature was the11 raised to 180° aiicl finally to 300° i h c tuhe lwing traversed by a ciirrent of dryliydrogen chloride.The anhydrous salt was then removed finely powdered and heated t o its melting point in contact with hydrogeii chloride which was then displaced by nitrogen and finally by air. The atomic weight of the saniarium was derived from the ratio SaC13:3Ag. A series of preliminary experiments in which the individual results were not in good agreement gave a mean value Sa=-150*45 and a final series of eight determinations in close agree- ment gave a mean value Sa=150*43. €3. 31. D. Precipitation Stability and Constitution of Hydrated Ferric Oxide Sols. I. MARKS NEIDLE ( J . 1 4 ? ? ~ ~ r . Che??~. S O C . 1917 39 2334-2350).-A systematic study of the precipitatioll of hydrated ferric oxide sols of varying purity and concentration by means of potassium sulphate.The sols were prepared by oxidising a solution of ferrous chloride containing 1 gram equiva- lent of ferrous chloride in 400 C.C. of solution by means of 3% hydrogen peroxide. The solutions were then dialysed and diluted t 9 the required concentrations. The content of iron and chlorine was estimated and the relative stability determined by measuring the volume of a standard solution ( M / S O O or &!/1600) of potassium sulphate required t o effect complete precipitation of the sol. A number of series of such clear sols were prepared and in each series the iron content was constant whilst the chlorine content varied. The results show that for a given iron concentration the stability increases with the chlorine concentration whilst for sols of given purity t h a t is for sols which have t h e same ratio Fe/Cl the stability decreases as the concentration increases this being most pronounced in very piire sols.It is shown that the maximuifi purity of a sol may be ascertained by graphic extrapolation. A general discussion is given of the results of Nicolardot and Duclaiiu (A. 1905 ii 167; 1906 ii 677). The author. advances :I cherrlic.sl theorv of the1 constitution of hydrated ferric oxide sols t o e>cF’liti\l thc relatioiiship between stability and composition J. F. S. A New Oxychloride of Tin. HARRY F. KELLER ( J . L4??zf~*. Chrnt. Soc. 1917. 39 2354-2356).-During the examination of metallic objects found in the aboriginal cemetery on Hogtown Bayou Santa Rosa County Florida the author noticed a number of cavities in a piece of tin which were lined with small shining crystals.The crystals were mostly in the form of thin plates but some were acicular. On heatinc the substniice melts and gives off acrid fumes which form a white sublimate without a trace of moisture. Analysis of a small qtiantity of the material leads to r2 comuosition corresnonding with the formula SnC12,Sn0. rSee also .7. ,COP. f ‘ l r e n i . It?(?. 1918 37 2 9 ~ . 1 J. F. R. Solubility of Bismuth Qxychloride in Hydrochloric Acid and its Relation to Complex Formation. ARTrIuR A. XOYEP FRANK Tv. R A m aiid JAMES A. BEATTIE ( J . Ll???er. (-‘/ic?)?. 8ov. 191 7. 39 3526- 2532).-The elertrical condnctivitly of a soliitlionii. 46 ABSTRACTS OF CHEMICAL PAPERS. of hydrochloric acid is diminished by the addition of bismutb chloride. The observed diminution can be most satisfactorily inter- preted on the assumption that chlorobismuthic acid of the formula H,BiCl is formed. Measurements of the solubility of bismuth oxychloride in hydro- chloric acid solutions of varying concentration a t 2 5 O afford sup- port for this hypothesis in the case of the more concentrated solu- tions whilst for the less concentrated acid solutions the solubility data suggest that the predominant complex acid has the formula HBiCl,. H. M. D.

ISSN:0368-1769    

DOI:10.1039/CA9181405042

出版商:RSC    

年代:1918

数据来源: RSC

摘要:

ii. 46 ABSTRACTS OF CHEMICAL PAPERS. Mineralogical Chemistry. Crystal Structure of Copper Pyrites determined by X-Rays. CHARLES L. BURDICK and JAMES H. ELLIS ( J . Amer. Chenz. Soc. 1917 39 2518-2525).-The X-ray interference effects obtained with a crystal of copper pyrites (CuFeS,) show that the iron and copper atoms together form a f ace-centred tetragonal lattice the planes perpendicular to the tetragonal axis consisting of alternate layers of copper atoms and iron atoms. The sulphur atoms are located on an exactly similar face-centred lattice the planes of sulphur atoms being situated a t equal distances from the plznes of iron and of copper atoms in each of the three axial directions. The density of copper pyrites calculated from the weights of the atoms and thhe distances between the atom planes is 4.24 whilst the observed densities recorded in the literature lie between 4.1 and 4.3.H. M. D. R. C. WELLS and B. S. BUTLER (1. TVashinqtom Acad. Sci. 1917 7 596-599) .-This mineral. a tungsten sulphide probably WS occurs intimately intermixed with other minerals in a compact ore from the Emma mine in the Little Cottonwood district Salt Lake' Co. Utah. Under the microscope it is seen as feathery flakes resembling graphite in appearance. It is lead-grey and opaque with metallic lustre and soft enough to mark paper. D about 7.4 (calculated from 6'43 of the specimen analysed allowing for impurities). The mineral is uiiattacked by hydrochloric or nitric acid but is decomposed by aqua regia. It is not oxidised by roasting in air. A bulk analysis of the ore gave W. R. Fo. Zn. Mn. Ni. Pb. As. Sb. Cu. Ag. SiO,. H,O. Totd. corresponding with WSo 61.5 ; pyrites 17.3 ; tennantite and tetra- liedrite 8.1 ; galena 4.7%. I n chemical composition and physical characters the mineral is analogous t o molybdenite (MoS,). Tungstenite a New Mineral. 44.7 29.1 8.S 0.4 0.6 0.3 4.1 1.0 0.8 1.3 0.4 0.3 0.7 92.5 L. J. S. The Photographic Spectra of Meteorites. SIR WIL14rAni CROOKES (Phil. Trans. 1917 [ A ] 217 411-430).-See this vol. ii 25.

ISSN:0368-1769    

DOI:10.1039/CA9181405046

出版商:RSC    

年代:1918

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY. Analytical Chemistry. ii. 47 Gas Interferometer Calibration. JUNIUS DAVID EDWARDS ( J . Arne?.. Chem. SOC. 1917 39 2382-2385).-A simple method of calibrating a Rayleigh-Zeiss gas interferometer is described. This differs mainly from the older method of using two gases of different refractive indices in using dry air free from carbon dioxide1 in both sides of the apparatus and changing the pressure of one side. J. F. S. The Direct Determination of the Hygroscopic Coefficient. FREDERICK J. ALWAY MILLARD A. KLINE and GUY R. MCDOLE ( J . Agric. Research 1917 11 147-165).-An investigation of Hilgarcl's method for the determination of the hygroscopic coefficient of soils (compare U.S. Dept. Agric. Div. Chem. Bull. 1893 38). If carried out exactly as described it gives trustworthy results but i t is more convenient t o replace the sheets of glazed paper by shallow aluminium 01- copper trays.The absorption boxes must not be increased in size and a larger number of samples must not be ex- posed in one box. The hygroscopic coefficient increases with rise in temperature (cornpare Lipman and Sharp A. 1912 ii 84). Preliminary drying of soils at 100-llOo does not affect' their hygro- scopicity and soils may be ground in steel mortars t c pass through a 1 Em. sieve without affecting this coefficient. It is preferable to expase the soil for twenty-four rather than for twelve hours and i t is essential to use only a very shallow layer of soil. Transference of the exposed soil from the boxes to weighing bottles must be) per- formed rapidly or the results obtained will be too low.W. G . Estimation of Sulphur in Urine. H. J. HAMBURGER (Zeitsch. physiol. Chem. 1917 100 221-240. Compare A. 1916 ii 641). -Application of the method previously described to the estimation of inorganic and ethereal sulphate and of neutral sulphur in urine. H. W. B. Gravimetric Estimation of Sulphuric Acid and Barium as Barium Sulphate. Z. KARAOGLANOW (2eit:ch. anal. Chem. 1917 56 417-439. Compare J. SOC. Chem. Ind. 1918 37 Feb.). -An investigation of the influence of various substances on the precipitation of barium sulphate Low results .are obtained when n large excess of barium chloride is added but when hydrochloric acid or nitric acid is also present the results are too high. Potassium salts cause the results to be low unless hydrochloric acid is also present when they become too high ; hydrochloric acid how ever increases the low results obtained in the presence of both potassium chloride and potassium sulphate.Sodium ammonium zinc magnesium and aluminium chlorides have no effect on theii. 4% AESTI<ACTS OE’ CHEMlCAL YAI’ICRS. l)recipitation ferric chloride makes the figures for the iiariurti sulphate t o be about 3% too low aiid chromium chloride has a similar effect . w. P. s. Estimation of Nitrogen in Explosives of the Type of Nitric Esters. BERNARDO ODDO (Gnzzcttn 1917 47 ii 145--15S). -In the method of estimation here described the reaction between nitrates sulphuric acid and mercury is employed but the process is madel gravimetric instead of volumetric.The explosive is dis- Folved in sulphuric acid in a small conical flask in which a small test-tube containing the mercury is placed. The flask is closed with a rubber stopper which carries an inlet tube and (as an outlet) a U-tube containing sulphuric acid. Purified carbon dioxide is passed through until all air is displaced (about forty minutes). The apparatus is then disconnected from the gas supply closed a t each end with a short rubber tube and glass rod and weighed. The end of the U-tube is then opened the mercury is poured into the flask by inclining the latter and the whole is shaken for a few minutes. Wlien the reaction is completz carbon dioxide is passed as before. After reweighing the percentage of nitrogen can be calculated from t!ic loss in weight.The results are satisfactory. R. v. s. Estimation of Metallic Iron in Ferrum Reductum. AUGUST EBERHARD (A rvh. I’lmrni. 1917 255 357-38t).-Ferruln reducturn used to be prepared by means of pure hydrogen at a not Loo high temperature genuine ferrurn lzydrogeiiio reducturn being thereby obtained. In recent years however impure hydrogen (COIL- taining carbon monoxide) and higher i eilzperatures have beeii einployed and these changes have so altered the quality and purity of the product t h a t the old methods of estimating the iron par- ticularly the iodometric methods no longer yield trustworthy resulls. For the technical method recommended see J . Aoc. Chew. Ind. 1918 37 3 9 A . c. s. Iso- and Meteropoly-acids. XV. Analytic and Synthetic Methods €or the Investigation of Heteropoly- acids. ARTHUR ROSENHEIM and JOEIANNES JAENICKE ( Z e i t s c h . auorg. Chenz. 1917 101 215-224) .-A critical sumiiiary is given with numerous references of the analytical methods employed for these acids in- cluding. estimations of water boric acid silica phosphoric arsenic molybdic and tungstic acids and alldis. A short outline of the general methods for preparing heteropoly-acids and salts is also given. E. 13. R.

ISSN:0368-1769    

DOI:10.1039/CA9181405047

出版商:RSC    

年代:1918

数据来源: RSC

摘要:

ii. 40 General and Physical Chemistry. Refractivity of Unsaturated Compounds. I. GERVAISE LE BAS (Z’mns. Pnmday SOC. 1917 13 53-60).-A discussion of the influence on refractive power of the ethylene and acetylene linkings of the carbonyl group and of conjugated carbonyl groups and of the refractivities of nitrites nitrates and oximino-com- pounds. H. M. D. The Lke Spectrum of Titanium and its Applications. A. DE GRAMONT (Compt. rend. 1918 166 94-99).-A study of the line spectrum of titanium when fused in the form of its oxide with lithium sodium or potassium carbonate and submitted to the action of a condensed spark or with the direct spark between two fragments of steel cont,aining titanium. The spectrophoto- graphs are reproduced in the original together with tables show- ing the rays more sensitive to the eye than t o a photographic plate and those capable of being photographed.The author suggests that the approximate amount of titanium in a steel may be deter- mined by observing which of the titanium rays can be detected. I n a similar manner this method may be used for the examination of minerals. W. G. T h e Application of the Quantum Hypothesis to Photo- chemistry. E. WARBURG (Xatwwiss. 1917 5 489-494 ; from Chem. Zentr. 1917 ii 587-588).-Restricting the term photo- chemistry to such reactions as do not yield electric end-products it is probable that the photochemical process does not involve the separat’ion of electrons because gases undergoing a photochemical change do not exhibit conductivity. It is necessary to distinguish between chemical processes produced directly by the influence of light and secondary reactions.Only those rays which are absorbed exert photochemical action and the effect is proportional to the absorbed radiation ; the chemical change caused by an absorption of radiation equivalent t o one gram-calorie is termed the “specific photochemical effect.” The hypothesis that photochemical absorp- tion occurs by quanta explains the concentration of the effect on relatively few molecules and accounts for the greater activity of the shorter wavelengths the effect being due to an increase in temperature of individual molecules. From the quantum hypo- thesis it follows that a molecule for example of hydrogen bromide can be directly decomposed by radiation only if 2c/h > q where c is a constant h the wavelength and q the heat effect in gram- calories per molecular weight on recombination of the decomposi- tion products.The apparent contradiction that photolysis can occur with ammonia for wave-lengths of h=0’209 in which case 2 c / h < g is explained by the possibility that a molecule of ammonia after absorption of a quantum without chemical alkra- CXIV. ii. 5ii. 50 ABSTRACTS OF CHEMICAL PAPERS. Lion may subsequently meet a sccoiid molecule with tlie result that the change 2NH3= N + 3H2 occurs for which q possesses a smaller value than for the decomposition of a single molecule into its constituent atoms. Processes in which the production of a false equilibrium is accompanied by a decrease and an increase of the free energy of the system are described respectively as photochemical actions of the first and second class.The photochemical yield is the proportion of the absorbed radiation which undergoes con- version into chemical energy and in the case of the decomposition of ammonia by the wave-length 0.209 amounts to a% a notable parallelism appearing to exist between the yields and those of the silent discharge. If the quantum is greater than the heat change in the primary photochemical process the excess will be converted into heat and heat will aho be produced in the secondary pro- cesses. If in a photolytic process the highest possible photo- chemical yield is desired and a minimum heat effect it is necessary that the quantum should be greater than the heat change involved in the primary process but only greater to the extent required for the fission of the photolyte and the heat effect in the secondary processes should be as small as possible. True Photochemical Processes.FRITZ WEIGERT (Zeitsch. Elektrochem. 1917 23 357-368).-A theoretical paper in which after differentiating between ideal and real photochemical pro- cesses and surveying a number of real photochemical reactions the author propounds a theory of the mechanism of these processes. It is shown that a transformation of light energy into other forms of energy only occurs when the electrons rotating round the posi- tive nucleus travel in a distorted path and when the distortion is produced by neighbouring particles which are in irregular relative motion. There must be therefore an optical coupling in the sense of Stark’s intermolecular influence which is closely connected with the broadening of spectrum lines.According t o the Le Chatelier-van’t Hoff principle it is to be expected that a change in the system will be brought about by the absorption of light in the sense that the distortion will be as far as possible removed. This would occur most easily by the separation of the distorting particles from one another. The foregoing is in accord with Bohr’s work (A. 1913 ii 689 943 1045) and is sufficient to include all known real photochemical phenomena and the transformation of light into heat. The (‘ equivalent law ” of Einstein holds for ideal photochemical reactions and in its deduction simple processes without the mutual influences of neighbouring particles alone were considered.This law may be extended by the assumption that in real photochemical processes not a single molecule but’ the whole of the optically coupled particles take part in the absorp- tion of an energy quantum and that therefore changes must take place over the whole of this region. This region contains fewer particles the higher the frequency of the absorbed light and the more dilute the partition of the mass; the lower the temperature the more nearly the relationships approach those of an ideal D. F. T.GENERAL AND PHY SEAL CHBMk3T.R-Y. ii. 5i process. The iuom particles displaced by the absorpt'ion of itu energy quantum the Iarger is the fraction of the thermal energy lost. Hence in solid and stabilised systems changes brought about by the absorption of energy persist for long periods and are the cause of characteristic changes and after-eff ects.Changes brought about in other bands by the distortion indicate the cause of a number of characteristic colour changes effected by light. This theory differs from previous theories inasmuch as it does not presuppose either a primary electron emission or an electron loosening. The consideration of the fact that a relative displace- ment of small masses brings about a distortion of the electron orbit leads a t once to the meaning of luminescence phenomena. Shoiild the displacement be the resnlt of light absorption theii Iluorescence follows. dn coiinexion with the foregoing the author briefly considers the photoelectric effect and the action of Rontgen rays.It is shown in the first place that a connexion between photochemical fluorescence and photoelectric effects does not! of necessity exist but they can in individual cases appear simul- taneously. The only direct process iiecessarily connected with the absorption of light is the relative displacement of the individual optically coupled particles and therewith a change in the absorp- tion under consideration which shows itself most clearly by its dependence on the intensity of the incident rays. J. F. S. The Disintegration Constant of Radiothorium. B. WALTER (Physikal. Zeitsch. 1917 18 584-585).-Measurements on the decay of the radiation through 5 mm. of lead of two preparations of radiothorium extending over 500 days have given a mean value for the half-period of 1.876 years or 685 days or 989 days for the period of average life.This is less than the accepted half-period 2 years and is in agreement with the recent statement of Meyer and Paneth ( W i e n . Ber. 1916 Abt. I I . n 125 1253) that the value could not be greater than 1.9 years as a maximum. F. S. l 1 Spark-lengths " in Hydrocarbon Gases and Vapours. ROBERT WRIGHT (T. 1918 113 79-80. Compare A. 1917 ii 403) .-Comparative measurements of the spark-lengths have been made in hydrogen benzene toluene and paraffin hydro- carbons. I n the paraffin series the spark-length decreases with increase in the molecular weight4 of the hydrocarbon. The insu- lating power of isopentane is exceptionally high being greater than that of n-pentane and greater also than that of hexane.The results for benzene and toluene show that the insulating power of these is approximately the same as that of hexane. H. M. D. The Charge and Dimensions of Ions and Dispersoids. G. VON HEVESY (Ir'olloid Zeitsch. 1917 21 129-136. Compare A. 1916 ii 594).-Evidence is put forward in support of the view that there is a tendency for electrically charged particles to 5-2ii. 52 ABSTRACTS OF CHEMICAL PAPERS. c*oiubiiic with w:tt er iiioleciiles until the 1)otential of the particle is reduced to about 70 millivolts. Since the potential of a charged ion is given by r' -t:,'KR where 6 is the charge R the radius ol' the particle aut2 I< t hr rlielertzic. constant of the solvent medium ii; follows that It =2.8 x ' l 0 - s ctti.for i L iioimal univalent ioii. For a multivalent~ ioii the radius will be proportional to the charge. Since the rate of diffusion of an ion depends mainly on the radius the diffusion constants may be expected to depend on the valency. The available data for uni- bi- ter- and quadri-valent ions give average values for the reciprocals of the diffusion constants which are in the ratio 1 :1*99:3.03:3*88. This relation is cou- sidered to afford strong support for the theory of constant ionic potential. The combination which takes place when multivalent electrolytes are dissolved in water is supposed to be directly connected with the formation of aqueous envelopes in accordance with the above tendency. This combination is relatively small in the case of uni- valent electrolytes.The ionic mobility of a normal univalent ion for which e==4.7 x 10-10 R=2*8 x cm. and P=0*07 volt is 48 when expressed in terms of the ordinary units. I n the case of ions of large size such as complex organic ions there is no tendency to combine with water in that the potential of the anhydrous ion is already less than that which tends to be set up by the interaction. I n a certain sense these slowly moving ions are to be regarded as abnormal. The same tendency is supposed t o operate in the case of colloidal particles. On the assumption that these particles are characterisecl by an electrical double layer a t the surface of contact with the dispersive medium the potential of the particles may be calculated from the equation V=E(R - R1)/KRlR2? in which R is the radius of the colloidal particle and R,- R the thickness of the electrical double layer.This thickness has been found to be about 5 x 10-7 cm. Since the mobility of the colloidal particles is of the same order as the normal ionic mobility it is possible to utilise the above relation t o obtain the contiexion between the charge on a colloidal particle and its radius. It is thus found that the charge is approximately proportional to the radius in the case of very small particles but that the charge increases much more rapidly than the radius. I n concentrated solutions of electrolytes the ions are not entirely independent and by taking into account the electrical interaction it is inferred that the niobility of ions in aqueous solutions will increase with the concentration of the ions provided that a suit- able correction is introduced for the change in viscosity.In the case of fused salts the mutual interaction becomes much more pronounced and at the same time the proportion of neutral molecules with which the ions may combine is greatly reduced with the result that the normal potential cannot be set up. The elec-GENERAL AND PHYSICAL CHEMISTRY. ii. 53 trical properties of fused electrolytes and in particular the high electrical conductivity are to be explained in terms of these peculiarities which distinguish the fused salts from ordinary solu- tions of electrolytes. G. VON HEVESY (KolloicZ Zeitsch. 1917 21 136-138. Compare preceding abstract).-If the number size and mobility of the particles of a colloid are known it is possible to calculate the charge on the particles and also the conductivity of the colloidal solution.By calculating the conductivity of a 0.1% solution of colloidal gold on various assumptions relative to the radius of the particles and comparing the results with the observed conductivity it is possible to derive information with respect to the actual size of the particles and the charge which they carry. It is probable that the maximum conducting power of a solution of a colloidal metal is less than 0-5 x 10-5 mho and the size of the particles which corre- spond with this is represented by R=lO-7 cm. where R is the radius. Although other colloidal substances appear tlo conduct somewhat better than the colloidal metals the conductivity woulcl appear t o be in all cases less than that of a 0*0001A-salt solution.The small conducting power of the colloids is to be attributed entirely to the sinall number of the particles for the charge carried by the par- ticles is always greater than thO charge of an ion of the same size. The ratio of the charges is in fact. given by (R / d + 1). where 72 is the radius of the particle and d the thickness of the electrical double layer = 5 x 10-7 cm. Fallacy of Determining the Electric Charge of Colloids by Capillarity. A. W. THOMAS and I . D. GARARD (J. Amer. (7Jbem. Soc. 1918 40 101-106).-It has been suggested that posi- tive and negative colloids can be distinguished by the difference in the capillary effects which are observed when strips of filter paper are dipped into the colloidal solutions. If the particles are negatively charged they are said to ascend the strip readily whereas positively charged particles are coagulated and deposited OIL the filter paper within a short distance of the surface of the solution.Experiments made with colloidal solutions of ferric hydroxide. chromium hydroxide arsenious sulphide antimony sulphide and xnolybdenum lead t o the conclusion that the basis of the above method is illusory and that there is no relation between the sign of the electrical charge and the capillary behsviour. The ascent of the colloidal particles depends on the dilution of the sol 011 tI1e presence of electrolytes on the nature of the surrounding atmo- sphere a d on the nature and previous treatment of the filter- paper strip.It) is probable that the supposed depeiidencc of th(1 c-apillary behaviour on the charge of the particles owes i t s oligirl 1 C) the circunistaiice that the observations were iriade with relatively cvncentrat,ed solutions of I he positivc yolloidq. the iipgat,ivp cnlloid:ll solutions being relatively dilute. H. M. D. The Conductivity of Dispersoids. H. M. D. H. M. D.ii. 54 ABSTRACTS OF CHEMICAL PAPERS. Electrochemical Behaviour of Nickel. A. SMITS and C. A. LOBRY DE BRUYN (Proc. K . 14kad. 'GVetensch. Arnsterdum 1918 20 394-403) .-Certain anomalies exhibited by nickel in its electro- chemical behaviour are attributable to the slow rate a t which internal equilibrium is established. In contact with air or hydrogen the anomalous behaviour is intensified and this appears to be due to the circumstance t h a t oxygen and hydrogen exert a negative catalytic influence. This influence of hydrogen explains the fact that the potential of a nickel electrode in contact with an atmosphere of hydrogen is tlhe same as that of the hydrogen elec- trode.I n reference t o the normal calomel electrode this potential is - 0.640 volt whereas the true equilibrium potential measured in a vacuiim is -0.480 volt. To obtain this value the hydrogen- ion concentration should not exceed 10-3 gram ion per litre. H. M. D. A Lead Standard Cell and a Determination of the Potential of the Lead Electrode. W. E. HENDERSON and has been found t h a t lead amalgams containing 2.5 t o 6% of lead may be used for the attainment of constant and reproducible Toten- tial differences.The cell P b amalgam 1 PbSO I Na2S0,,10H20 I Hg2S041Hg has an E.M.F. which may be represented by the equation for temperatures between 1 8 O and 3OC. The E.M.P. is reproducible t o within threehundredths of a millivolt but a gradual diminution of the E.M.F. occurs when the cell is kept for an extended period of time. From the temperature coefficient of the cell the heat of the reaction 0.5PbzHg + Hg,SO =PbSO + 2*5Hg is found t o be 42139 cal. The value derived from thermochemical data is 41785 cal. Measurements of the E.M.F. of a cell of the above type with the amalgam replaced by pure lead gave 0.96973 a t 25O. The difference of 0.0051 volt is used in the derivation of the E.M.F. of the cell Pb I PbC1 IO.lNKC11 Hg2CI I'Hg.giving 0.5187 volt a t 25O. This is further employed in the calculation of the' potential of the norinal lead electrode using available data for the solubili'ty and degree of ioiiisation of lead chloride. The E.M.F. of the cell obtained by combination of the normal lead electrode with the WlN-calomel electrode a t 2 5 O is 0.4696 volt. [See J. Soc. Chem,. I??d. 1918 March.] H. M. D. S. R. MILNER (Phil. Hag. 1918 [vi] 35 214-220).-The author contends t h a t the true degree of ionisation of an electrolyte cannot be obtained from either osmotic or conductivity data. The failure of the law of mass action in its application to solutions of strong electrolytes i s said t o be such t h a t insuperable difficulties stand in the way of ally t,heory which ascribes the variations in conduc*tivity to rha11p~ i l l the llumber of the iow These difficulties are avoided if the GEBHARD STEGEMAN ( J .Amer. Chem. sot. 1918 40 84-89).-It E = 0.96463 + 0*000174(t - 25) + 0*00000038(t - 25)z Effect of Interionic Forces on Electrolytes.GENERAL AND PHYSICAL CHEMISTRY. ii. 55 variations in conductivity are attributed to the action of the elec- trical field on the ionic mobility. Equivalent Conductance of Electrolytes in Dilute Aqueous Solution. I. The Water Correction. EDWARD lv. WASHBURN ( J . Anter. Chena. Soc. 1918 40 106-122).-The introduction of improvements in the Kohlrausch method for the determination of the conductivity of electrolytes (compare A. 1917 ii 10) has made it possible to obtain increased accuracy in the experimental measurement and to investigate in particular the conductance of electrolytes in very dilute solution.I n this paper which lorms the first of a series in which the results of these investigations are described the author discusses the’ question of the magnitude and nature of the water correction the influence of carbonic acid and the products to which this gives rise by metathesis in dilute soln- tions of various kinds of electrolytes. The fact that the strong acids in very dilute solution appear to be abnormal in their con- ducting power even when the observed conductivity has been corrected for carbonic acid suggests strongly that basic or saline impurities are present and since these affect the magnitude of the carbonic acid correction it is considered that accurate data for the conductivity of dilute solutions can only be obtained by the use of ultra-pure water instead of water which is in equilibrium with the atmosphere.Equivalent Conductance of Electrolytes in Dilute Aqueous Solution. 11. The Extrapolation of Conductivity Data to Zero Concentration. EDWARD W. WASHBURN ( J . Anzer. Chem. SOC. 1918 40 122-131).-The methods previously employed by Ilohlrausch Noyes Kraus and Bray and by Bates for the estima- tion of the limiting molecular conductivity are critically examined and rejectled as untrustworthy on the ground that. most of these involve the assumption t h a t the functional relation between the conductivity and the concentration which holds for the lowest measurable range of concentrations will also hold down to zero concentration.A new graphical method of extrapolation is described by which the author claims t o avoid the errors involved in the “arbitrary function ” methods and also those which attach to direct graphin4 extrapolation. The proposed method rests on two assumptions the first of which is t h a t with decreasing concentration ( c ) the value of ca2/(l - a) = k decreases and aqxoximates to a constant value ko a t extreme dilutions. According t o the second assumption the relation between c and Ic must be such t h a t deviations from the law of mass action do not increase with the dilution. The actual procedure in applying the method consists in plotting values of k against values of c for different assumed values of A and reject- ing those values which cause the curve to exhibit radical chsnqes in direction in the region of very dilute solution. I t is said to be possible t o determine A with a precision of 0.01% if the con- rluctivity data are of this order of acciiracy and extend t o I’ = 0-00002. H.M. D. H. M. D.ii. 56 ABSTRACTS OP CHEMICAL PAPERS. The method of extrapolation described by Bates (A 1913 ii 466) involves the assumption of the validity of the Storch equa- tion but otherwise resembles the method now proposed and when applied to the data for potassium chloride gives very nearly the samel result. H. M. D. Equivalent Conductance of Electrolytes in Dilute Aqueous Solution. 111. A Study of Dilute Solutions of Potassium Chloride. HENRY J. WEILAND ( J . ,4nzcr. Chenz. SOC. 1918 40 131-150).-A method for the preparation of “ultra-pure con- ductivity water ’’ is described in which ordinary conductivity water (k=0*6 to 0.8 x 106 mho) is heated to near its boiling point in a large quartz still a current of carefully purified air being passed through the water.The water vapour is condensed in a block-tin tuba and collected in a quartz receiver. The specific conductance of the water obtained in this way may vary from 0.05 to 0.07 x 10-6 mho a t 1B0 and has been used in the investigation of the Conductivity of very dilute solutions of potassium chloride. The conductivity cell of about 3 litres capacity is made of quartz and is provided with co-axial cylindrical platinum elec- trodes which are so constructed that the water does not come into contact with anything but.platinum or quartz The dilute solu- tions examined were prepared in the cell out of contact with the atmosphere by the successive introduction of small crystals of potassium chloride weighing about 0.005 gram. The error resulting from the adsorption of salt from these dilute solutions by the quartz surface of the cell has been examined and found to be negligible. The experimental data for solutions varying in concentration from about 0*000012\7 to 0.001N show that! the quantity k = c a 2 / l - a has a constant value for solutions for which the con- centration is less than 0.0001N. The results afford therefore direct experimental proof of the validity of the mass law in its application to the ionisation of potassium chloride a t very low concentrations.The limiting value of the equivalent conductance atl 1 8 O was found to be 129*64+0-02 (compare preceding abstract). The empirical relations suggested by Bates and by Kraus for use in extrapolating to zero concentration have been tested by refer- eiice t o the data for solutions between c-0 and c=O.005 and the conclusion is drawn t’hat these do not reproduce satisfactorily the experimental results 017er this range of concentrations. H. M. D. Equivalent Conductance of Electrolytes in Dilute Aqueous Solution. IV. Two Laws Governing the Ionisation Equilibrium of Strong Electrolytes in Dilute Solutions anda New Rule by means of which the Equivalent Con- ductance at Infinite Dilution can be Determined from a Single Conductance Measurement. EDWAWD W. WASHBURN (?7.A w f r . Cke/,i. Soc. 191s. 40 150--15S).--The behaviour ofGENERAL AND PIIY SICAL CHEMISTRY. ii. 51 eiectxolytes in very tiiliite solution as exemplified by the data for i'otassiuin chloride in the preceding paper and by the most accurate coiductivit y work of Kohlrausch arid his collaborators has led tho author to the following general conclusions. I n sufficiently dilute solutions (c < O*OOOl,V) all uni-univalent salts of strong acids and bases are ionised in accordance with the requirements of the law of mass action and the ionisation constant is the same for all. The values of k = ca2/ 1 - a for such salts are identical in sufficiently dilute solution and this identity persists up to concentrations which are higher the more closely the salts under comparison resemble each other.According to this second generalisation the identity in the ionisation relations extends beyond the concentration up to which the salts in question satisfy the requirements of the mass law. I n terms of the equation Ac,2C/A,(A,-Ac)=K the state- ment implies that K is independent of the nature of the salt and on simplification this equation leads to the relation Ao=Rc]a where a is independent of the nature of the salt. For C=O*OOOIAi\T this equation becomes A = 1.00475 A,. Evidence in support of the above conclusions is furnished by the dat'a for the salts of the alkali metals which are examined in detail. R. M. D. Electrolytic Deposition of Alloys and their Metallographic and Mechanical Investigation. VIII. Cathodic Deposits of Iron and Iron-Nickel Alloys obtained at the Ordinary Temperature under High Hydrogen Pressure.ROBERT KREMANN and HERMANN BREYMESSER (Monatsh. 1917 38 359-384. Compare A. 1915 ii 511).-In previous papers (Zoc. cit.) i t has been shown that electrolytic iron deposited at ordinary pressures and temperatures is charged with hydrogen and admixed with ferric hydroxide; it' is also brittle and hard. These condi- tions are shown to be due to the simultaneous liberation of hydrogen a t the cathode. It is shown theoretically that the simultaneous liberation of hydrogen can be prevented if the electrolysis is carried out under a high hydrogen pressure. To test this deduction iV-solutions of ferrous sulphate have been electrolysed under a pressure of 20 atm. of hydrogen with a C.D.of 0.25 amp./dm2 and 0.75 amp./dmz. A further series of experiments was carried out with solutions to which 10 grams of citric acid per litre were added. In the first two cases it is shown that the current efficiency is 99.33-99*46% whereas in the last case it is only 88.57%. The deposits obtained in these cases have been compared with those obtained under 1 atm. pressure of hydrogen and in the presence of 0*15N-sulphuric acid. It is shown that the material obtained under the higher pressure is composed of larger cryEtals than that under the lower pressure. The hydrogen content of the high- pressure specimens is much less than that of the low-pressure speci- mens whilst the hardness is very much reduced by the deposition under high hydrogen pressure The specimens obtained under the present conditions are much less brittle than those obtained under other conditions whereas the magnetic properties of the deposits 5"ii.58 ABSTRACTS OF CHEMICAL PAPERS. are iiot affected Ly chsiige iii the coiiditioiis of depositioii. Electro lytic iron produced under pressure when immersed in il'-ferrous sulphate solution shows a t once the equilibrium potential of -0.417 volt whilst iron deposited under other conditions only reaches this value after some considerable time. A further series of experiments was made under similar condi- tions with mixed solutions of ferrous sulphate 0-7N and nickel sulphate 0*3iV. I n this case the nickel-iron deposits did not show the improvement observed in the case of iron alone. A number of microphotographs of the deposits is appended t o the paper.[See also J . SOC. Chem. Ind. 1918 March.] J. F. S. Temperature Determinations by Eutectic Alloys. CHARLES P. STEINMETZ ( J . Ampr. Client. Soc. 1918 40 96-loo).- Eutectic points of alloys furnish a more satisfactory means for the determination of temperature than the melting points of pure metals. I n general the eutectic point is not dependent t o the same extent on the purity of the substance and the alloys afford a more numerous series of fixed points on the scale. The cooling curves of a number of alloys have been examined and twelve of these found to give satisfactory eutectic tempera- tures ranging from 6 9 0 5 ~ t o 194'0O. The approximate composition of these low-melting eutectic alloys is recorded in the paper.[See J . SOC. Chem. Ind. 1918 March.] H. M. D. Solubility of Sodium Sulphate as a means of Determining Temperatures. THEODORE W. RICHARDS and VICTOR YNGVE ( J . Amer. Chem. SOC. 1918 40 164-174).-The solubility of a sub- stance with a large temperature coefficient may be used for the accurate measurement of temperatures. Between 15O and 25O the solubility of sodium sulphate varies rapidly with the temperature and since it may easily be obtained in a pure condition and readily gives a saturated solution it has been examined with a view t o its application in the measurement of temperature. Measurements of the solubility were made a t accurately deter- mined temperatures in the neighbourhood of 15O 175O 20° and 25O. The results are represented very closely by the equation log s= 0.659970 + 0.02963889t + 0.0000688925t2 in which s is the solubility expressed as the number of grams of sodium sulphate per 100 grams of water. It is claimed that the solubility method described will permit of the determination of temperatures to within O*0lo and may be used for the standardisation of thermometers.H. M. D. The Transition Temperatures of Strontium Chloride and Strontium Bromide as Fixed Points in Thermometry. THEODORE W. RTCHARDS and VICTOR YNGVE ( J . Amer. Chem. Soc. 1918 40. 89-95).-The transition temperat'ures have been determined by methods described in previous papers (compare A. 1914 ii 244). The purification of strontium chloride can be effected by re-GENERAL AND PHYSICAL CHEMISTRY. ii. 59 c.ryslalliuiiig above arid afterwards below the transition tempera- ture.It is found that barium can be readily removed by recryst>allising below the transition temperature (61°) so as t o obtain the hexahydrate. The calcium cannot be removed in this way but recrystallisation above the transition temperature yields the dihydrate from which the calcium is rapidly eliminated. I n a similar way strontium nitrate may be purified by crystal- lising out under conditions which yield the anhydrous salt whereby the calcium is removed. The barium may then be removed sub- sequently by recrystallising the hexahydrated chloride prepared from the partially purified nitrate. The temperature at which the hexahydrate of strontium chloride is transformed into the dihydrate has been found to be 61.341O at atmospheric pressure on the hydrogen scale.Preliminary experiments show that hexahydrated strontium bromide is similarly transformed into the dihyclrate at aboiit 88*6F. !See J . SOC. Chem. 1?d. 1918 109~.] 13. M. D. Theory of Specific Heats. WALTHER JANKOWSKY (Zeitsch. Rlektrochem. 191 7 23 368-371).-A theoretical paper in which on the basis of the older kinetic theory it is shown that without making an assumption of an equal partition of energy it is possible to derive a formula for the specific heat' of gases and vapours. This formula has the form c=e,iz(l + i ) / m . n . i i n which c is the true specific heat that is the heat at constant volume em the mean energy change expressed in calories of a molecule when the temperature is raised lo i is the ratio o€ the change of molecular energy to that of the sum of the atomic energies i =eqn l e a .n and ?z is the number of atoms in the molecule. This formula is tested on a large number of gases and vapours and is found to give good agreement. The dependence of the specific heat on temperature is shown to be due to changes in the value of i. This is a direct con- tradiction of the theory of equal energy partition. This formula gives a simple theoretical basis t o the Law of Dulong-Petit and Joule and explains quantitatively the divergencies and also shows that a strict following of the law is impossible. A further formula is deduced for the calculation of the ratio of the specific heat a t constant pressure to that a t constant volume. This has the forms k=l+2C/3cVm and k=1/1-2Cf3cPrn in which C=2*98 k=cpfcV and m is the molecular weight.J. F. S. Calculation .of Gas Equilibria IV. D. TREADWELL (Zeitsch. Elektrochem. 1917 23 270-272).-A mathematical paper in which by a series of approximations the author shows that the value of a the chemical constant which is expressed by Planck as a = R 1Ogep - C'p logeT + r,/ T can on thermodynamic grounds be proved to have the value a = R log,p + r0/ T - C p log,T. I n both equations p is the vapour pressure C'p the specific heat at constant pressure of the vapour ro the heat of vaporisation a t absolute zero and C p the specific heat of the liquid phase. J. F. S. 5*-3ii. 60 ABSTRACTS OF CHEMICAL PAPERS. Specific Heat of Liquid Ammonia. NATH~N S. OSBOHNP and MILTON s.VAN TIUSEN (./. Anzrr. Chem. Soc. 1918 40 1 -13).-Measurements of the specific heat of liquid ainmovia havr been iiiatle according t,o two independent methocls. 1 II one ot 1 hese the change in temperature produced by a measured quantity of heat under saturation conditions was determined whilst in the other the calorimeter was kept full of liquid a t constant pressure greater than the saturation pressure the change in temperature produced by the added heat energy being corrected for the heat content of the expelled liquid. The interval of temperature covered by the measurements ranges from -45O to 45O and over this range the specific heat increases from 1.058 at - 4 5 O to 1.173 a t 4 5 O . The dependence of the specific heat on the temperature is represented by the empirical equation c = 0.7498 - 0*0001368 + 4.0263 2/ 133 - 8 in which c is expressed in terms of the 20° calorie and 0 is the temperature. H.M. D. Latent Heat of Vaporisation of Ammonia. NATHAN S. OSBORNE and MILTON S. VAN DUSEN ( J . Amer. Chenz. SOC. 1918 40 14-25) .-The calorimeter used in the determination of the specific heat of liquid ammonia (compare preceding abstract) was modified so as to render it suitable for the measurement of the heat' OF vaporisat'ion. A known quantity of heat developed and measured electrically is employed to vaporise a portion of the liquid ammonia contained in the calorimeter the ammonia vapour lwing withdrawn at measured temperature and pressure and its amount estimated. Corrections due to thermal leakage were reduced t o a minimum by special methods of manipulation.The results obtained show that the latent heat of vaporisation decreases from 333.0 cal. a t -42O to 252.6 cal. at 49O. The variation of t'he latent heat with the temperature - - - - may be expressed by the empirical equation L = 32.968 4 133 - 8 - 0*5895(133 - O ) in which 8 represents the actual temperature and 133 represents the critical temperature. From the latent heat of vaporisation and the specific heat of the liquid under the pressure of its saturated vapour the authors have calculated the specific heat of saturated ammonia vapour. Expressed in joules per gram per degree this varies in a con- tinuous manner from -4.42 a t - 4 5 O to -3.36 a t 45O. To reduce these numbers to 20° calories they must be divided by 4.163.H. M. D. The Vapour Pressure of Liquid Ammonia up to the Critical Temperature. 11. FREDERICK G. KEYES and R. B. BROWNLEE ( J . Amer. Clzem. SOC. 1918 40 25-45).-The vapour pressures of liquid ammonia have been measured between Oo and the critical temperature by a method involving the use of a piston gauge. The dependence of the vapour pressure on the tempera- ture may be expressed by the equation log p = - 196965 / T-I- 16.19785 - 0.04238582' + 5.4131 x 10-51'2-3-2715 x lO-RTT3. ThisGENERAL AND PHYSICAL CHEMISTRY. ii. G I equation holds satisfactorily for vapour pressures down to the freezing point ( - 7 7 O ) . The boiling point was found to be - 33-20 k 0.05'. 13. M. D. Formula giving the Saturated Vapour Pressure of a Monatomic Liquid. E. AHI~S (Conapt.mid. 1918 166 193-197). -The author deduces the formulae I1 = d 2 / ~ and where 7 is the reduced temperature and 11 is the reduced pressure of the saturated vapour and shows that the calculated results agree with the observed results in the cases of krypton xenon arid argon. W. G. Vapour Pressures of Liquid Metals. JOEL H. HILDEBRAND ( J . Amer. Chem. SOC. 1918 40 45-49).-1t has been shown previously (A. 1915 ii 416) that the heat of vaporisation divided by the absolute vaporisation temperature is the same for all normal liquids provided that comparison is made a t temperatures for which the concentrations of the saturated vapours have the same value. On the basis of this relation it is possible to superimpose the vapuur-pressure curve for one substance on that of another by means of a single constant a which expresses the ratio of the absolute temperatures referred t o above.By t,aking mercury as the standard liquid for which the vapour pressure may be represented by the equation log p = - 3140/ T + 7-85. i t is shown that' the vapour pressures of a number of other liquid rnet'als may be expressed by the equation log p= - 3140a/ T +- 7.85 +log u in which a varies from 1-74 for cadmium to 4-90 for iron. By meaiis of the tabulated values of u for the different metals it is possible t o calculate the vapour pressure a t any temperature and also the heat of vaporisation. H. M. D. Apparatus for the Determination of Boiling Points. ALFRED EDWARDS ( J . SOC. Ckent. Znd. 1918 37 38~).-A siinpfe form of boilirig-pointl apparatus is described which provides for tho complete immersion of the thermometer stem in the heated vapour.The still-head is traversed by a somewhat narrower inner tube with a hole near the top through which the vapour from the boiling liquid escapes into the outer tube passing therefrom to a condenser tube which is sealed into the still-head a t its lower end. The condensed liquid tends to seal the space between the inner s n c l outer tubes in its lower portion and thereby to secure a regular stream of vapour through t'he inner tube in which the therrrio- meter is supported. H. M. D. TheHeat of Formation of Liquid Water from its Ions. J . A. MULLER (Bull. Soc. chin,. 1918 [ivl. 23 8-13).-C~ing the method previously described (compare A. 1913 ii 115> theii.G2 ABSTRACTS OF CHEMICAL PAPERS. author has determined the heats of reaction of sulphuric aud hydrochloric acids with potassium hydroxide in aqueous solution a t infinite dilution and from his results has calculated the heat of formation of water from its ions. The values obtained were with sulphuric acid 13,966 cal. and with hydrochloric acid 14,003 cal. W. G . Thermochemical Studies. The Heat of Combustion of the Paraffins. DANIELAGERLOF ( J . p ~ . Chem. 1917 [ii] 96 123-124. Compare A. 1905 ii 76).-The heat of combustion of ,,-octane observed by direct measurement (Richards and Jesse A. 1910 ii 269) agrees closely with the value calculated with the aid of the author's hypothesis (loc. cit.) which thereby receives confirmation. D. F. T. The Heat of Ionisation in Aqueous Solution of Crystalline Barium Sulphate and the Solubility of this Salt in Water.J. A. MULLEI~ (Bull. Soc. c?&n. 1918 [iv] 23 13-16).-From measurements of the heats of reaction of barium chloride and sulphuric acid at increasing dilutions and determining the limits towards which these tend at three temperatures the following expression is found for the value of Q the heat of combination of the ions Ba and SO p = 105502.32 - 696*857T + 1.21187'2 T being the absolute temperature. The heat of ionisation of crystalline barium sulphate in aqueous solution is the inverse of this. Froin this it is possible to calculate the ratio of the solubilities of barium sulphate at different temperatures and the results agree with those of van't Hoff. [See also J.SOC. Chem. Znd. 1918 March.] W. G . Adsorption Compounds and Adsorption. 11. Replace- ment from the Surface. 1,. BERCZELLER and Sr. HETJ~NYI (Uiocl~e in. Zeitsch. 19 17 84 11 8-1 36) .-Stalagmometric measurements of the effect of addition of alcohols to solutions of various cryddloid and colloid substances. S. B. S. Utilisation of the Adsorptive Power of Fuller's Earth for Chemical Separations. ATHERTON SEIDELL (J. Amel.. Chewz. SOC. 1918 40 312-328).-A comparison has been made of the adsorptive capacities of thirty-six samples of fuller's earth and other similar clays by experiments on the adsorption of quinine bisulphate and methylene-blue. The adsorptive power of a given quantity of a particular sample increases with the concentration of the unadsorbed substance in the aqueous solution and also with the time of contact although the rate of adsorption gradually diminishes. The method of measurement consisted in mixing 1 gram of the fuller's earth sample with 10 C.C.of water and adding t o the mix- ture measured volumes of 1% quinine bisulphate or 0.5% methylene- blue solution. The tubes containing the mixtures were shaken for half an hour and the solutions then examined for the adsorbedGENERAL AND PHYSICAL CHEMISTRY. ii. 63 substances. From a series of such tests it was possible to obtain comparative numbers for the adsorption powers of the samples. I n the case of both the quinine salt and the methylene-blue the free base only is adsorbed. When both are present in the solution in equal amounts they are adsorbed to very nearly the same extent.If the fuller’s earth is first shaken with methylene-blue and then with quinine bisulphate a small amount of the latter is adsorbed and only a trace of the former liberated. If the order is reversed a much larger proportion of methylene-blue is adsorbed and a con- siderable amount of the quinine salt is displaced. The experiments show further the influence of dilution of the acidity of the solution and of the presence of ethyl alcohol and sucrose. [See also J . SOC. Chent. Ind. 1915 March.] H. &I. D. Preparation of Uniform Collodion Membranes for Dialysis. CHESTER 3. FARMER ( J . Biol. Chem. 1917 32 447-453. Com- pare Brown A. 1917 ii 362).-The membrane is prepared by filling a glass tube with collodion solution inverting and allowing to drain for one minute.The tube is then dried in a current of air for one minute and afterwards filled with cold water. After a few minutes the thin membrane can be removed from the walls of the glass tube with the aid of a pair of forceps. Convenient apparatus for performing these operations is described in detail in the original paper. H. W. B. The Colloidal Membrane its Properties and its Function in the Osmotic System. FRABK TINKER (Tranq. Fnrnday Soc. 1917 37 133-140).-Although i t is probable that the average kinetic energy of a molecule in the liquid state is the same as in the state of vapour this must not be taken t o imply that the average pressure of a solute molecule has the same value in the two states. In the solution a large proportion of the volume is occupied by the solvent molecules with the result that the free space is greatly reduced and the pressure which the solute mole- cules would exert on an imaginary flame is consequently much greater than the corresponding gas pressure.The internal bombardment pressure of the solute must therefore iiot be confused with the osmotic pressure which in the author’s opinion is an external mechanical pressure. The supposed analogy between osmotic and gas pressure is also considered to have no real foundation in that this analogy fails t o account for the funda- mental phenomena of diffusion. The mechanism involved in an osmotic system is said to be quite different from that which pro- duces gas pressure there being no pressure on the membrane unless the solution is compressed.This pressure is then exerted by the solution as a whole and not by the individual molecules whether of solute or solvent’. The similarity between a dilute solution and a gas is due to the fact that both experience no change in internal energy when theii 64 ABSTRACTS OF CHEMICAL PAPNRS. volume is varied. Equality in tlhis respect does not however afford any proof that the mechanism involved in gas and osmotic pressure is of the same nature. Reference is made to the importance of the study of the proper- ties of the membrane and a brief account is given of the author’s work on this subject. ALFRED FV. PORTER (Y’ram. Fayaday SOC. 1917 13 123-132).-The cause of osmotic pressure is discussed and it is pointed out that the kinetic theory is the only theory yet advanced which reproduces directly the values for the osmotic pressure which have been actually obtained in experiments with dilute solutions.The arguments against the kinetic theory which rest largely on the dissimilarity of the con- ditions in liquids and gases have been greatly weakened as the result of observations on the Brownian motion. These observations afford the experimental basis for a kinetic theory of liquids accord- ing to which solute and solvent molecules are in a state of rapid movement. The osmotic pressure represents the dynamical effect of this thermal motion of the solute molecules and in order to obtain a mental picture of the effect of the presence of the solute i t may be supposed that the molecular bombardmeat of the mole- cules of the solute on the boundary surface tends to enlarge the boundaries and thereby to relieve the total pressure on the solvent.In other words the kinetic pressure resulting from the thermal agitation of the solute molecules acts outwardly and diminishes the Laplacian pressure by an equivalenti amount. It is shown that the data for the osmotic pressures of sucrose solutions a t 20° can be represented satisfactorily by the equation P(v-b)=RT in which b is a constant which is great’er than the volume of the sucrose. On the assumption that this is due to the hydration of the sucrosel molecules it is found that about 5-3 mole- cules of water are associated with a molecule of sucrose. If this equation is applied t o the whole of Morse’s results and hydration values calculated for diff’erent concentrations and temperatures the numbers are not quite regular but show clearly that hydration diminishes with increasing concentration.The values for dilute solutions are surprisingly high but’ are considered to be quite plausible and it is suggested that the variation in solubility with the temperature may be due t o changes in the degree of hydration. According to the equation connecting osmotic pressure with the latent heat of dilution of the solution the latter quantity depends on the variation of PIT with the temperature T. I f these varia- tions derived from Morse’s values a t loo and 30° are compared with those calculated from measurements of the heatl of dilntion a t 20° the dBgree of correspondence is found t o be quite satis- factory.H. M. D. Osmotic Pressure in Relation to the Constitution of Water and the Hydration of the Solute. W. R. BOUSFIELD (T?.ans. E’arnday Sot.? 1917 13 141-155).-The aiithor’s previous H. M. D. Kinetic Theory of Osmotic Pressure.GENERAL AND PHYSICAL CHEMISTRY. ii. ti5 work 011 the properties of solutions is considered with reference to the kinetic interpretation of osmotic pressure. This interpretatioii rejects the idea that the molecules of the solute are directly responsible for the osmotic pressure and a modified gas theory is put forward which involves the assumption that water is a mix- ture of three kinds of molecules vapour liquid and ice molecules represented by H,O (H20)a and (H,O) respectively and attributes the osmotic pressure to the thermal agitation of the vapour mole- cules.The validity of the ideal gas equation for dilute solutioiis is supposed to indicate that these hydrol molscules comport them- selves towards changes of pressure and temperature in the same way as the molecules of a gas. The addition of a solute to water is said to be accompanied by a reduction in the proportion of both the vapour and ice molecules in the equilibrium mixture resulting in a diminution of the vapour pressure and a lowering of the freezing point. Reduction of the molecular interspace by external pressure raises the vapour pressure and the osmotic pressure is defined as the liquid pressure under which the external vapour pressure of a solution is equal t o the internal vapour pressure of the pure solvent.The relations between the osmotic pressure the lowering of the vapour pressure and the freezing point are discussed in reference tlo the above theory and i t is claimed that the various osmotic data are brought into line with ot’her properties by t’hs assumptioil that’ the active hydrol molecules enter into combination with the solute molecules. It is said that different properties lead to the same value for the degree of hydration of the solute. H. M. D. Solubility and Internal Pressure. JOEL H. HILUEBRANU ( J . Amer. Chenz. SOC. 1918 40 198).-Corrections to a previous paper (this vol. ii 36). H. 04. D. Changes in Volume during Solution. 111. GBEGORY YAur BAXTER ( J . Amer. Chem. SOC. 1918 40 192-193).-1f A l l A f B f *lB’ and A’H represent the four salts formed by the ions A U Ll’ and B’ then the apparent volume in solution of one of these may I)e obtained if the apparent volumes in solution of the three others are known.The calculation depends on the fact that the sum of the apparent volumes of LIB and A’B’ is equal to the sum of the apparent volumes of AB’ and A’B. The apparent volume of dissolved calcium carbonate obtained in this way from the apparent volumes of calcium chloride sodium carbonate and sodium chloride is 3.0 C.C. Since the molecular volume of solid calcium carbonate is 36.9 c.c. the change in volume on dissolution is 3.0 - 36.9 = - 33.9 C.C. per mol. The contraction is thus more than 90% of the volume of the solid salt. IT. M. I). The Structure in Steps in certain Anisotropic Liquids.F. GRANDJEAN (Coinpt. r e n d . 1918 166 165-167).-This struc- ture already found in ethyl azoxybenzoate and cinnamate (com- pare Bull Soc. franc. Min. 39 167) has been found also in theii. 66 ABSTRACTS OF CHEMICAL PAPERS. oleates aiid the positive phase of cholesteryl decoate. It is described in detail. This structure in steps aiid particularly the existence of steps of extremely slight thickness separated from steps infinitely near by abrupt lateral surfaces reveals a discontinuous property of the liquid which is not observed in the group of azoxyphenetole. W. G . Precipitation of Colloidal Gold and Platinum on Metallic Surfaces. ELLWOOD B. S P ~ A R and KENrjETlf n. I ~ A H N (J. Awzer. C’hem. SOC. 1918 40 181-184).-The precipitation of colloidal gold and platinum solutions when brought into contact’ with polished plates of zinc steel nickel lead tin copper or platinum has been examined with results which indicate thatl the rate of coagu- lation increases with the electro-positive character of the metal.The effectl also depends on the nature of the metal surface in that the rate of coagulation for a given metal decreases if the surface is roughened or if the metal is employed in a finely divided condition. It is suggested that ions of the active metal are formed and that these are adsorbed by the colloidal particles thereby neutralising their negative charge. I n support of this view it has been found that copper does not bring about! coagulation if the colloidal gold or platinum solution is freed from air by the passage of a current of purified hydrogen.[See J . SOC. Chein. Tnd. 1918 March.] H. M. D. Laws of Chemical Equilibrium. ERSKINE D. WILLIAMSON and GEORGE TV. MOREY ( J . Anzer. Cherri. SOC. 1918 40 49-59). -A theoretical paper in which the authors derive general equa- tions for the equilibrium in heterogeneous chemical systems by methods which are essentially based on the work of Gibbs. Special forms of equations applicable to systems of simple type are specifically ref erred to. Pressure-Temperature Curves in Univariant Systems. GEORGE ’CV. MOREY and ERSKINE D. WILLIAMSON ( J . Amer. Chenr. ,Sot. 1918 40 59-84. Compare preceding abstract).-The pressure-temperature curves for univariant systems are discussed in reference to Gibbs’s equations. The conditions under which different pressure-temperature curves become coincident are ex- amined and a method is developed by which the order of succession of the pressure-temperature curves intersecting a t an invariant point can be determined.The applicability of the method is shown by reference to the five curves which melt in the quintuple points characteristic of the ternary system H,O-K,SiO,-SiO,. H. M. D. H. M. D. Univariant Equilibria in the Ternary System-Water Sodium Sulphate Ammonium Sulphate. C. MATIGNC N and F. MEYER (Compt. rend. 1917 165 787-789).-The experi- mental data recorded show the composition of solutions which areGENERAL AND PHYSICAL CHEMISTRY. ii. 67 ia equilibrium with two solid substances. The two sulphates combine to form the double sulphate NaNH4S0,,2H,O antl numbers are given for solutions saturated with respect to the double salt and Glauber's salt between -13O and 25'5O double salt and anhydrous sodium sulphate between 29O and 5S0 double salt and ammonium sulphate between -19O and 58O and with respect t o anhydrous sodium sulphate and ammonium sulphate betweei 1 62'5O and logo.A solution saturated with sodium sulphate boils a t 1 0 2 O and contains 2.10 mols. per 1000 grams of solution. Similarly the b. p. of saturated ammonium sulphate solution is 108'9O and it cont'ains 3.922 mols. per 1000 grains whilst a solution saturated with respect to the two sulphates boils at 1 1 1 O and contains 1.125 mols. Na,SO apd 3.175 niols. (NH,),SO per 1000 grams of solution. [See further J . s o c . Chem. T ? d .1918 29~.] Heterogeneous Equilibria between Aqueous and Metallic Solutions. G. McP. SMITH and 8. A. BRALEY (J. Anzer. C h m . Sot. 1918 40 197).-A correction of results recorded in a previous paper (A. 1917 ii 455).-The error necessitates a further in- vestigation of the ionisation relations in mixtures of sodium and strontium chlorides. H. M. D. Invariant Equilibria in the Ternary System Water- Sodium Sulphate-Ammonium Sulphate. C. MATIGNON and F. MEYER (Compt. rend. 1918 166 115-119).-A study of the equilibrium of the solution in the presence of the various com- binations of three solid phases the cooling curves being plotted. I n a trilinear diagram with co-ordinates giving respectively the temperature the concentration of anhydrous sodium sulphate antl the concentration of ammonium sulphate are shown the surfaces corresponding with the states of equilibrium of the solution with respect to one solid phase.[See also J . SOC. Chem. Ind. 1918 March .] W. G. Effect of Hydrogen Chloride on the Nitrogen-Hydrogen Equilibrium. E. B. LUDLAM (TTCL~S. E'nrnday SOC. 19',7 13 43-52) .-The observations made by Deville suggest that the stability of ammonia a t high temperatures is increased very con- siderably by the presence of hydrogen chloride and lead to thc supposition that the equilibrium between nitrogen hydrogen and ammonia will be displaced in favour of the ammonia i f hydrogen chloride is added to the mixture. Experiments in which a mixture containing equivalent quanti- ties of nitrogen hydrogen and hydrogen chloride was subjected t o the action of an electrically heated platinum wire or carbon rod stretched along the axis of a water-cooled tube afforded no evidence in support of the above hypothesis.The soaking of the carbon rod in solutions of sodium calcium or magnesium chloride made no difference to the result. Other experiments in which a mixture of nitrogen and hydrogen was passed slowly through a quartz tube containing sugar charcoal H. M. D.ii. GS ABSTRACTS OF CHEMICAL PAPERS. a t about 800° gave results which seemed to show thatl t'he amillonis formed was increased when hydrogen chloride was added to the nitrogen-hydrogen mixture although the effect was much smaller than that calculated from the mass action equation. On the assumption that' the smallness of the effect was due to the slowness of the reaction attempts were t'hen made t o approach the equilibrium condition by starting with ammonium chloride.Il'eighed quantities of this were accordingly heated in an evacuated quartz tube in presence of gold silver copper and iron with results which seemed to show that ammonium chloride is not nearly so stable a t high temperatures as Deville's observations would suggest. The evidence afforded by these experiments pointed to iron as the most active catalyst and further observations were therefore made in which nitrogen hydrogen and hydrogen zhloride were passed through a layer of iron asbest'os heated a t about 450O. Even a t this low temperature ferrous chloride is formed and sublimes and the volatility of this substance would evidently be a serious obstacle to the use of iron in practice even if the catalytic activity of the metal were very considerable.H. M. D. Equilibrium Data on the Polybromides and Polyiodides of Potassium. G. A. L r N H A w ( J . ilnzer. Chenz. SOC. 1918 40 155-163).-0n the assumption that KBr and KBr are present in aqueous solutdons which contain potassium bromide and bromine the constitution of the solution is determined by the equations [Brg']/[BrfJ[Br2J = K' and [Br,]j[Br3][Br,J=Kf'. By reference to Worley's data for 26*5O it is shown that' K' remains very nearly constantl= 15.9 i f it is assumed that li" =1*2. A t Oo Rf = 19.6 and Xff=2.08 and at' 3 2 . 6 O Rf=15.5 and 1</f=1*06. From the values of the constants at the two lower temperatures the author calculates the heat of the reactions Brf + Br2(aq) = Br,' - 1290 cal.and Br3/ + Br,(aq) =B:,/ - 3390 cal. When the value K/f=1*2 for 2 6 . 5 O is applied t o solutions which are saturated with bromine the calculated value of lif is appreci- ably higher than that indicated above and it is suggested that this may be due to the formation of KBr7. Measurements of the ratio of distribution of iodine between carbon tetrachloride and water a t 25O show that the ratio of the concentrations expressed in mols. per 1000 grams of solvent is constant= 57.7. The constitution of iodine-potassiuni iodide solutions is also dis- cussed briefly. H. M. D. Influence of Substitution in the Components on the Equilibrium in Binary Solutions. X. Equilibria in Binary Solutions of p-Toluidine and Carbamide respectively with Nitro-derivatives of Benzene.ROBERT KREMANN and BRUNO PET~RITSCHEK (Hotzutsh. 1917 38 385-404. Compare A. 1905 ii 307; 1906 ii 268; 1912 ii 1151).-The binary systems ;rr-toluidine with the three dinitrobenzenes 2 4-dinitrotoluene and the three nitrophenols respectively and carbamide with the threeGENERAL AND PHYSICAL CHEMISTRY. ii. 60 cliiiitrobenzenes aud I! 4-dinitrotoluerte respectively have bee t i iiivestigated by means of time-cooling curves. It is shown in the cease of p-toluidiiiei with the three dinitrobenzenes am1 with 2 4-dinit rotolnene gives no compounds but only simple eutectics ; with m- and p-nitrophenols a cornpound is formed in each case. With 7t~-nitrophenol and ptoluidine the compound produced consists of one molecule of each constituent whilst with p-nitro- phenol the compound consists of two molecules of p-nitrophenol to one molecule of ptoluidine.In the case of o-nitrophenol and p-toluidine no compounds are formed but simply a eutectic. Carbamide does not form any compounds in any of the mixtures examined and in all cases there are large gaps in the mixture series. As a result of the experiments the authors state that the tendency to cornpound formation with the dinitrobenzenes is deter- mined by the residual affinity of the benzene nucleus and not by the affinity of the amino-group whereas in the case of the nitro- phenols the amino-group is the determining factor. Influence of Substitution in the Components on the Equilibrium in Binary Solutions.XI. Binary Solution Equilibria between Phenol and the Three Isomeric Nitro- phenols respectively with the Three Isomeric Phenylene Diamines. ROBERT KREHANN and BRUNO PETRITSCHEK (Moizntsh. 1917 38 405-444. Compare preceding abstract) .-By means of cooling curves the authors have investigated the twelve possible binary systems formed between phenol and the three nitrophenols on the one hand and the three phenylenediamines on the other. The system phenol-p-phenylenediamine gives rise to the compound consisting of one molecule of diamine t o two molecules of phenol. This compound forms a eutectic with phenol a t 40° and with pphenylenediamine a t 94O. The system phenol-m-phenylene- diamine gives rise to a compound made up of three molecules of phenol and two molecules of the diamine; this compound forms a eutectk with phenol at' 24O and with diamine a t 41° and has m.p. 52'6O. I n the case of the system phenol-o-phenylenediamine two compounds appear ; these consist respectively of four molecules of phenol and one molecule of the diamine and one molecule of each component. The eutectics in the case of the first compound lie atl 2 8 O with phenol and 2 9 O with the second compound. The system pnitrophenol-o-phenylenediamine forms a single cornpound composed of two molecules of nitrophenol and one molecule of the diamine (m. p. 87*9O). This compound with nitrophenol has a eutectic a t 85.5O and with diamine a t 7 8 O . A compound of similar composition is formed in the system p-nitrophenol-nz-phenylene- diamine; this melts at 1 1 9 * 9 O and its eutectics lie atl 1 0 2 O with nitrophenol and 5 2 ' 4 O with the diamine.In the system p-nitro- phenol-p-phenylenediamine two compounds are found ; these have compositions (a) four molecudes of nitrophenol t o one molecule of the diamine and ( 6 ) one molecule of nitrophenol to one mole- cule of the diamine respectively. The eutectics lie a t 109.5O for p-nitrophenol and compound n 117*li0 for compound n and com- J. F. S.ii. 70 ABSTRACTS OF CHEMICAL PAPERS. pou~id I) a i d 107' for the couipotmd b aiid tche diamine. The systems o-nitrophenol and the three phenylenediamines do not give rise to compounds; the eutectick in these cases lie a t 4 2 . 5 O for p-phenylenediainine 3 3 ' 5 O for m-phenylenediamine and 38*S0 for 0-p hen y 1 ene diamine .The system m-nitr op henol-m-phen ylen e- diamine gives rise t o two compounds composed of two molecules of nitrophenol and one molecule of the diamine and one molecule of nitrophenol and one molecule of the diamine respectively. In the system m-nitrophenol-o-phenylenediamine two compounds are found; these are two molecules of nitrophenol with one molecule of o-phenylenediamine and an equimolecular compound. Similar rela ti onships are found in the system m-ni t rophenol-p-ph en ylen e- diamine. J. F. S. A Complete Review of Solutions of Oceanic Salts. 111. ERNST JANECKE (Zeitsch. anorg. Chem. 1918 102 41-65. Compare A. 1917 ii 527).-In the previous paper a graphic representation was devised for the doubled ternary system (Na,,K,,Ng) (Cl,,SO,) in presence of sodium chloride as a constant solid phase.The diagram took the form of a triangle for any particular temperature the corners of the triangle corresponding with the three salts MgCl 2KC1 Na,SO,. The temperature co- ordinate being perpendicular to the plane o€ the triangle the com- plete diagram took the form of a three-sided prism. Although sodium chloride is always present' as a solid phase the quantity in solution or the quantity of water corresponding with saturatlion with salt a t different temperatures has been hitherto neglected. In the present paper this new factor is taken into account. A t first the new variable is considered in connexion with the simple salts represented by the corners of the triangle and later with respect to the systems associated with the sides.For an interpretation of the numerous diagrams given the original paper must be referred to. [See further J . SOC. Chew?. Ind. 1918 March.] E. H. R. Chemical Kinetics. U. PRATOLONGO (Atti R. Accad. Lincei 1917 [v] 26 ii 182-190).-The author bases on Marcelin's work (Contribution 3 1'8tude de la cine'tique physico-chimique Thesis Paris 1914) the essentials of a new thermodynamics of irreversible phenomena. T. H. P. Effect of Temperature and of Pressure on the Limits of Inflammability of Mixtures of Methane and Air. WALTER MASON and RICHARD VERNON WHEELER (T. 1918 113 45-57).- Theoretical considerations indicate that the effect of increasing the initial temperature of mixtures of inflammable gases with air should be to widen the difference in the composition of the mix- tures which correspond with the upper and lower limits of inflam- mabili ty .Experiments made with mixtures of methane and air show that the percentage of methane corresponding with the lower limit,GENERAL AND PHYSICAL CHEMISTRY. ii. 71 cleweases f r m i 6-00'$) of iuetliane when the initial teluperaturtl of the mixture is 20° to 3.25% for an initial temperature of 700'. In the case of the higher limit mixture the percentage of methane increases slowly with the initial temperature of the mixture up to about 600° after which there is a considerable augmentation of the rate of increase of the methane content. I t is suggested that this is probably due to the disturbing influence of surface com- bustion of the methane during the interval which elapses between the introduction of the gas mixture into the heated explosion vessel and the passing of the igniting spark.I n general the results obtained for the influence of the initial temperature on the limits of inflammability agree closely with those obtained by Taffanel (Contpt. rend. 1915 157 593). Experiments made to determine the influence of pressure on the composition of the limit mixtures show that the percentage of methane increases with pressure for both the lower and upper mixtures. This result is in agreement with previous observations made by Terres and Plenz ( J . Gasbeleucht. 1914 57 990 1001 1016 1025). The smaller effect obtained by these authors in the case of the upper limit mixtures is presumed to be due to the circumstance that they did not make use of a sufficiently powerful source of ignition in order to obtain strictly comparable results.The lowestl pressure at which self-propagation of flame occurs in mixtures of methane and air was found to be 120 nim. when the initial temperature was atmospheric. In similar experiments Burrell and Robertson (U.S. Bureau of Mines Technical Paper No. 121 1916) obtained a limiting pressure of 300 mm. The differ- ence between the two results is explicable on the asumption that the igniting source employed by these authors was not sufficiently powerful. I n these circumstances their results give merely the limiting pressure for ignition by a spark discharge of particular intensity. The mixtures which correspond with the lowest limiting pres- sures contain between 8.75 and 9.40% of methane these numbers being derived from observations in which the initial temperatures were 20° 250° and 500O.11. J. P. TREUB (Proc. K. Akud. TVetensch. Amsterdam 1918 20 343-357. Compare A. 1917 ii 528).-From a mathematical discussion of the ideal case in which the saponification of a triglyceride takes place in solution the ester groups being equivalent and no complications arising it is shown that the relative concentration of free glycerol a t any moment is equal to the third power of the relative concentration of the free fatty acid in the case of stagewise saponification that is passage through the di- and mono-glycerides. The same holds good for the ideal case of esterification. The experimental results obtained when trilaurin is saponified with strong sulphuric acid show only very slight deviations from this rule the deviations being due to the fact that the three ester groups are not perfectly equi- valent.Rather greater deviations are found in the esterification of H. M. D. The Saponification of Fats.ii. 7 2 ABSTRACTS OF CHBMTCAL PAPERS. 1au t*ic acid slit1 glycerol by strong sulphuric wi(1. [See also J . Dynamics of Nitrile Formation from Acid Anhydrides and b i d e s . I. Investigation of the Reaction O(COPh),+ COPh.NH -+ 2Ph*CO,H+PhCN by Methods based on the Phase Rule. ROBERT KREMANN and MAX WENZING (i%?onats?L. 1917 38 445-456).-In a series of experiments designed for the investigation of the binary mixture benzoic anhydride-benzamide the authors found that the temperature of the primary crystal- lisation varied with the time during which the mixture had been heated and also with the temperature. This they were able to show was due to the reaction O(COPh),+COPh*NH,+ 2Ph*C02H + PhCN.To follow this reaction mixt’ures of the four substances taking part were made in a number of different propor- tions commencing with 100% of the substances on the right hand side of the equation and ending with 100% of the substances on the left hand side but always so that the molecular ratio of the benzoic acid to the benzamide was 2 l and that of the benzoic anhydride to the benzamide was 1:1. These mixtures were rapidly heated to 98O and then allowed to cool and the tempera- ture of primary crystallisstion noted. The crystallisation tem- peratures were plotted against the composition and an analytical curve produced which on the assumption that no chemical change had occurred gives the composition of any mixture in which the proper ratios of the two sides of the equation are maintained directly from the temperature of its primary cryst’allisation.The reaction was then studied quantities of benzoic anhydride and benzamide in molecular proportions were mixed in a closed vessel heated to 9 8 O or 123O and the temperature of primary crystallisa- tion measured at stated intervals of time (one to one hundred hours) and from the analytical curve the progress of the reaction ascertained. It is shown that the reaction is bimolecular and at 9So has a value 1;=0*053 whilst a t 123O k=0*24. The tempera- ture-coefficient is therefore 1.8 for loo.It is shown also that the reverse reaction does not take place to the extent of more than 1%. J. F. S. Influence of Carbon Monoxide on the Velocity of Catalytic Hydrogenation. EDWARD BRADFORD MAXTED (Trans. Farada;ll ,Sot. 1917 13 36-42).-Measurements have been made of the rate of absorption of hydrogen by olive oil a t 180° in presence of small quantities of carbon monoxide. The absorption vessel con- taining the oil and a nickel catalyst was connected to the gas- measuring tube by rubber tubing and was adjusted so that the contents could be continuously and thoroughly shaken during the progress of the absorption. Comparative experiments with pure hydrogen and with hydrogen containing from 0.25 t o 2% of carbon monoxide show that the rate of hydrogenation is very considerably reduced by these quan- tities of carbon monoxide.The curve obtained by plotting the hydrogen absorption for a given interval of time against the per- ,\‘or. ( ‘ h ~ n ? . 7nd. 191 8 March.] w. G.GENERAL AND PHYSICAL CHEMISTRY. ii. 73 centage of carbon monoxide in the hydrogen is convex towards the origin indicating that the retarding influence of successive increments in th0 carbon monoxide content decreases with increase in the quantity of the poisonous gas. Apart from the poisoning effect of the carbon monoxide the admixture of this gas dilutes the hydrogen but this effect can be readily calculated and allowed for. H. M. D. Hydrogenation under the Influence of Colloidal Catalysts and how to account for this Process.J. BOESEKEN and H. W HOFSTEDE (Proc. K . Akad. Wetensch. Amsterdam 1918 20 424-434) .-The question of the mechanism of colloidal metal catalysts in hydrogenation processes is discussed and the results of observations are recorded on the rate a t which hydrogen is ab- sorbed by solutions of cinnamic acid cinnamic esters and ethyl undecenoate in presence of colloidal palladium. These results are not sufficiently regular t o admit of mathematical treatment and the authors infer that the normal course of the reaction is dis- turbed by impurities in the hydrogen by coagulation of the cata- lyst and by other unknown factors. [See J . SOC. C'hem. Znd. 1918 March.] H. M. D. The Fundamental Values of the Quantities 71 and & for different Elements in Connexion with the Periodic System.V. The Elements of the Carbon and Titanium Groups. J. J. VAN LAAR (Proc. K . Akad. Wetensch. Amsterdam 1918 20 492-504. Compare A. 1916 ii 386 610; 1917 ii 67).-The methods previously described have been applied to the calculation of the values of b and . \ l a f o r the elements of the carbon and titanium groups. The critical data for these elements are of course not known but the values of 6 can be obtained from the compounds for which in certain cases the requisite data are avail- able. The chief result to which the author's calculations lead is that the value of J a must be very large ranging from 0.32 for carbon to 0.40 for lead. This is supposed to indicate that the attractive forces measured by 4% are those of the free atonis.The estimated values of .\ln and b and also of the critical tmi- perature and pressure are recorded in tables. H. M. D. The Fundamental Values of the Quantities b and Jcu for different Elements in Connexion with the Periodic System. VI. The Alkali Metals. J. J. VAN LAAR (Proc. K. A k d . Il'etetzsch. A msterdam. 1918 20 505-519. Compare preceding abstract).-An attempt is made to estimate the values of 7 and \/. for the alkali metals. the approximate value of the critical 1 emyerature required in the calculations being derived froin the irielting points and boiling points. The physical properties of tlhc alkali metals necessitate the assumption of high valnes for tIho tritraction constant and this is assumed to be connected with th(h existence of these elements in the atomic condition.The estiiriatcdii. 74 ABSTRACTS OF CHEMICAL PAPERS. values of the critical data and of b and J a are recorded in tabular form . H. M. D. Considerations on the Nature of Chemical Minity and of the Valency of Atoms G. CIAMICIAN and M. YADOA (Atti R. nccad. Lincei 1917 [v] 26 ii 165-173).-The bearing of the results of recent work on the structure of the atom and on valency is discussed. T. H. P. Vacuum Balance Cases. BERntAiv BLOUNT and WILLIAM H. WOODCOCK (T. 1918 113 81-84).-Attempts have been made to construct a vacuum balance case of gun-metal. On account of the porosity of the metal it was not found possible to reduce the rate of leakage much below that represented by 0.01 mm. per hour. Better results were obtained with a glass case consisting of a large bell-jar with a side tubulus through which the rider is con- trolled by an arrangement which is commonly made use of in the ordinary glass hypodermic syringe. A balance case constructed on these lines has been found t o give satisfactory results. By means of a Gaede pump it can be exhausted to 0*001 mm. and the vacuum can be maintained for more than an hour. H. M. D. Met.hod for Preventing Salts from Creeping over the Sides of Evaporating Dishes. W. 0. ROBINSOW ( J . Amer. Chem. SOC. 1918 40 197).-Creeping of salts can be prevented by paint- ing a strip about 6-7 mm. wide round the inner rim of the dish with collodion. The film cont,ains no non-volatile residue and can be easily burnt off. Lecture Experiment on the Vapour Pressure of Solutions. H. S. VAN KLOOSTER ( J . Amer. Chesn. SOC. 1918 40 193-195). -A simple apparatus is described for demonstrating the lowering of the vapour pressure of a volatile liquid on the addition of a foreign non-volatile substancs. It consists of an outer glass tube in which the pure liquid is boiled and an inner tube containing the solution. The inner tube is constricted somewhat about the middle of i€s length and at' its lower end is sealed on to a narrow tube which is bent round t o form a U with the wider tube and is used ,as a gauge tube. The constriction serves t o close the inner tube when all the air has been removed and this is conveniently effected by a rubber cork attached t o a glass rod. When the outer tube is closed and the liquid boils vapour passes through the solution vi2 the gauge tube and when the air has been displaced the inner tube is closed by the rubber stopper. The level of the solution in the gauge tube is then found t o be less than that in the wider tube. H. M. D. H. M. D. Preparation of Argon as a Lecture Experiment. W. P. .TORISSEW (Chem. TVeekbZad 1917 14 1151-1153).-A descrip- toin of an apparatus for demonstrating the extraction of argon.. INORGANIC CHEMISTRY. 11. 75 from air the oxygen being absorbed by phosphorus and the nitro- gen by a mixture of magnesium-powder fresh quick-lime and sodium. A. J. W.

ISSN:0368-1769    

DOI:10.1039/CA9181405049

出版商:RSC    

年代:1918

数据来源: RSC

摘要:

i . 50 ABSTRACTS OF CHEMICAL PAPERS. Physiological Chemistry. The Sugar of the Blood. S. GUTNANN and 0. ADLER (Bioc~hc11~. Zeitsch. 1917 83 11-17).-The proteins of tlie blood were pre- cipitated by Schenk’s method and the reducing action (on copper solutions) of the protein-free blood was determined in the filtrate directly and after heating with 2.2% hydrochloric acid. No difference was found in the two sets of estimations whence the conclusion is drawn that the blood contains no polysaccharides. Neither were polysaccliarides t o be detected when ordinary starch was added to blood which was then rendered protein-free by Schenk’s method. I n the case where soluble starch was added how- ever the reduction was greater after hydrolysis. S. B. S. Residual Reducing Power of the Blood.0. ScHuazni (Zeitsch. physiol. Chem. 1917 100 215-220).-PoIemical against Griesbach and Strassner (see A. 1917 i 491). H. W. B. A New Ferment of the Leucocytes of Blood and Pus Lipoidase. NOEL FIESSINGER and R E N ~ CLOGNE (Compt. rend. 1917 165 730-732).-The leucocytes of blood and of acute sup- puratdon have the property of secreting an enzyme capable of hydrolysing lecithin in feebly alkaline solution. The enzyme is destroyed by heating a t 56-60° in half an hour and does not’ act in strongly acid or alkaline solution. The red corpuscles in large quan- tity and apparently normal serum exert an inhibitory action on the enzyme. This lipoidase is distinguished by its thermoIabiIity from the lipase occurring in the leucocytes. W. G. The Presence of Phosphates in Human Blood Serum.11. Acid Soluble (Total) Phosphorus pre-existing Ortho- phosphoric Acid and Residual ” Phosphorus in Normal Cases. JOH. FEIGL (Biochem. Zeitsch. 1917 83 81-95. Compare A. 1917 i 520).-The difference between the acid-soluble phos- phorus and the orthophosphoric acid which can be estimated directly in the serum is called the residual phosphorus. I n the sera of healthy individuals i t amounts generally to more than 0.5 mg. per 100 C.C. of serum or 15% of the total acid-soluble phosphorus. The amount is subcject to variations. S. B. S. Estimation of Small Amounts of Calcium particularly in Blood. JOHN 0. HALVERSON and OLAF BERGEIM (J. Bz‘ol. Chenz. 1917 32 159-170. Compare A. 1916 ii 270).-Full details are given of tho method previously described.Normal serum contains about 10 mg. of calcium in 100 C.C. of serum. The amount of calcium in human milk varies between 27 and 33 mg. per 100 C.U. B. w. B.PHYSIOLOGICAL CHEMISTRY. i. 51 Calcium Content of the Blood-serum in certain Patho- logical Conditions. JOHN 0. HALVERSON HENRY K. MOHLER and OLAF BERGEIM ( J . B i d . Chem. 1917 32 171-179. Compare pre- ceding abstract).. -In nearly all pathological conditions tJhe amount of' calcium in the blood-serum does not differ appreciably from that found in health. Slight decreases are observed in some cases of urxmia eclampsia and pneumonia. H. W. R. Diffusion of Electrolytes through the Membranes of Living Cells. V. Additive Effect of Salt and Base and the Antagonistic Effect of Salt and Acid. JACQUES L o E B (J.BioZ. Clhern. 1917 32 147-158. Compare A 1917 i 102).-Tlie author has previously shown that the effects of the addition of ,z second salt on the diffusion of potassium salts through the mem- branes of Fundzilus eggs are analogous to the effects of salts on globulins which are insoluble in water soluble in a moderate con- centration and insoluble again in a very high concentration of salt. It is suggested that the! diffusion of potassium salts is dependent therefore on t.he solution of a certain constituent of the membrane with properties resembling those of a globulin. This hypothesis is supported by the analogy which is now shown t o exist between the effects of salt on the action of acids and bases in the case of the membrane of the k'u?zduZus egg and in that of globulins respec- tively.When Fundulus eggs are put into solutions of bases not suffi- ciently concentrated to injure the embryo the bases become injuri- ous when neutral salts in low concentrations are added. An addi- tive effect of salt and base is observed also a t higher concentrations of the base. On the other hand the addition of a neutral salt to an acid which kills rapidly the embryo of Fundulus eggs produces an antagonistic effect which is also observed f o r lower concentra- tions of acids. T'he minimal quantity of a salt required for these effects diminishes with an increase in the valency of both anion and cation of the salt. By comparing the effects on the egg with those on the newly-hatched embryo it is shown that these additive and antagonistic effects are due in the case of the egg of Fundulus to an influence of the salt on the rate of diffusion of alkali and acid through the membrane of the egg accelerating the diffusion of alkali and retarding the diffusion of acid.Since therefore salts increase the rate of diffusion of certain electrolytes through the membrane of the egg of Fundulus when they are also able to dissolve globulins and they retard or inhibit the diffusion when they are likely t80 prevent the solution of globulins i t is probable that the substance in the membrane on which the diffusion of electrolytes depends is a globulin. H. W. B. Cholesterol in Animal Organs. I. LIFSCH~~TZ (Biochenz. Zeitsch. 1917 83 18-~7).-Cholesterol was prepared from ox- brain in the usual manner and sufficient digitonin was added t o the alcoholic solution to precipitate about onethird to one-half ofi.52 ABSTRACTS OF CHEMICAL PAPERS. the cholesterol. From this precipitate the ordinary cholesterol could be isolated by Windaus's method. The filtrate from the digitonin-cholesterol compound yielded however a cholesterol which crystallised in an elliptical form and melted after repeated recrystallisations from ethyl and methyl alcohols a t 139-141° or 5O below the m. p. of the ordinary form. From ox-blood cholesterol was also prepared and this consisted chiefly of the substance with elliptical form (m. p. 139-141°) from which the acetate (m. p. 109-110°) was prepared. The latter melts about 4O below the aoetate of the ordinary cholesterol. The cholesterol of tlhe organs mostly concerned in the resorption of fat consists for the greatest part' of ordinary (rhombic) cholesterol whereas the cholesterol of the kidneys is almost exclusively of the elliptical form.S. B. S. Metabolism of Sugar in the Central Nervous System. ELSE HIRSCHBERG and HANS WINTERSTEIN (Zeitsch physiol. Chem. 1917 100 185-202).-When the spinal cords of frogs are placed in a saline solution containing dextrose. and oxygen is bubbled through the solution the dextrose gradually disappears. I n the absence of the spinal cords the dextrose content of the solution remains unchanged. The nerve tissue is therefore capable of inducing glycolysis. The membranes surrounding the spinal cord appear to be impermeable to dextrose because the glycolysis becomes more pronounced when the membranes are removed before placing in the dextrosesaline solution.In these circumstances a t the ordinary temperatare from 4 t o 5 mg. of dextrose per 1 gram of cord disappear in twenty-four hours. The glycolysis varies with the temperature and gradually declines throughout the ex- periment being no longer recognisable after the second day. The latt'er observation indicates that the results cannot be attributed to bacterial actdon. Lack of oxygen rapidly causes an irreversible decline in the glycolysis; alcohol ethyl carbamate and also a trace of a soluble calcium salt (0.1% calcium chloride) lomer the glyco- lysis but after the removal of the inhibiting agent it rapidly returns to its former level. Electrical stimulation of the tissue evokes a great acceleration of the rate of disappearance of the dextrose which reaches twice the normal value.If the spinal cords are reduced to a fine state of division the r a k of glycolysis is markedly increased presumably on account of the increased surface of contact between tissue and dextrose solution. It is a function of the living tissue; the boiled material does not induce any glycolysis. The consumption of dextrose by the minced spinal cord is influenced in the same way as in the case of the intact organ by the various factors above described with the exception that' electrical stimulation does not evoke any increase in glycolysis after the normal structure of the tissue has been destroyed. H. W. B.PHYSIOLOGICAL CHEMISTRY. i. 53 The Carbohydrate Metabolism in the Surviving Liver of the Dog.J. ABELIN and J. MA. DE CORRAL (Bzoclienz. Zeztsch. 1917 83 62-73).-Although ths perfusion of peptone solution has no influence on the glycogen content of the liver of a rabbit. it diminishes the amount of this carbohydrate in the liver of the dog. Perfusion of adrenaline is without actioii on the glycogen degradation in the livers both of the rabbit and the dog. S. B. S. Biological Analysis of Diets Producing Pellagra. 11. Minimum Requirements of the two Unidentified Dietary Factors for Maintenance as contrasted with Growth. E. V. MCCOLLUM and N. SIMMONDS ( J . Bio2. Chem. 1917 32 181-194) .-The authors describe feeding experiments on rats in which the relative and absolute quantities of the two factors (‘fat- soluble A ” and “water-soluble B,” in the diet are varied.The former factor is contributed in the form of butter-fat and the latter in wheat-germ and it is found that 1% of each of these factors in the diet is just sufficient to maintain the weight of adult rats. I n these circumstances however the life of the animal is uncertain and the rats may die unexpectedly without any apparently sufficient cause. The life of young rats may be main- tained for considerable periods without growth when minimum amounts of the two factors are present and subsequently growth may occur in proportion to the increased amounts of the factors administered. The extent of growth depends on the amount of that factor which is present in relatively the smaller proportion ; in other words increased growth after an increased proportion of “fatrsoluble A ” does not occur unless the amount of “water- soluble B ” is increased t o a corresponding extent. The results are illustrated by numerous charts.H. W. B. The Significance of the so-called Steric Hindrance ” in Biological Processes. I. The Influence of the Methyl Group in the Ring. OSKAR BAUDISCH and FRANZ KLAUS (Bzochein. Xeitsch. 1917 83 6-lO).-Attention is directed to the fact that subst’ances containing a methyl group are less reactive biologically than the corresponding substances without this group. The state- ment is illustrated by reference to the therapeutic action of the rosaniline dyes of acridine-yellow and trypoflavin and of atoxyl and its methyl derivatives. I n all cases the more methyl groups a substance contains the smaller its therapeutic activity. Other instances quoted are the differences between crystal-violet and new- magenta when used as stains by Gram’s method and the differences between chrysarobin and cignolin (non-methylated substance) when employed according t o Unna for the treatment of psoriasis. S. B. S.

ISSN:0368-1769    

DOI:10.1039/CA9181400050

出版商:RSC    

年代:1918

数据来源: RSC