摘要:

THE QUART E R LY JOURNAL OF THE CHEMICAL SOCIETY OF LONDON. LONDON HIPPOLYTE BAILLIERE 219 REGENT STREET AND 440 BROADWAY NEW YORK U.8. PARIS 3. B. BAILLIERE RUE HAUTEFEUIZLE MADRID BAILLP BAILLIERE CALLE DEL PILINCIPC. 1861. LOHDOH PRINTED BY HAI1RISON AND SONS ST. MARTIN’S LANE W.Q CONTENTS OF THE THIRTEENTH VOLUXE. On Biniodacetic Acid . By W. H. Pexkiu. F.C,$. and B. F. Duppa. Eq ........ PW 1 Description of an Hermetically Sealed Barometer . By Richard Adie .........*. 7 Acid. 3y TY.I%.Perkin.Action sf Pentachloride of Phosphorus an T~ta;ricF.C.S.,and 8. F.Duppa. Esq ............................................................................ 9 On the Application of Electrolysis to the Detec6ion of the Poisonous Met& Mixtures containing Organic Matters .By Charles L. Bloxam ............... 12 ORthe Composition of Air from Mount Blanc . By Dr.E. Franklanfl F.X.S. 22 On Refining GIold wben alloyed with Tin or Antimony. so 88 to render it fit for the purpose of Coinage. By Robert Warrington .......................................... 31 On some Derivatives frpm the Olefines . By Frederick Guthrie ........................ 35 On the Crystallized Hydrates of Bar@ and Strontia . By Charles L. Bloxam 48 Mhellaneous Obsmations . Ry A. W. Hofmann. F.R.S. ,(Oordhkued Vol. x.* p. all) :-4 . Action of Nitrous Acid upon Nitrophenylene-diamine .................... 61 5 . Action of Bisulphide of Carbon upon Amybmine ............................60 6. On the use of Pentachloride of Antimony in the Pmpw4ion of Chlorine-compounds .............................................................................. 63 7 . On Di-iodide of Methglene .................................................................... 65 8 . Dibromide of Ethylene ....................................................................... 67 9 . Wetamorphosis of Nonobrominated Ethylene .................................... 68 10. Iodide of Ethyl ...................................................................................... 69 11. On the Deportment of Cyanate of Ethyl with Ethylate of Sodium.... 70 12. On Ulycerin ........................................................................................... 71 13.Dinitratoluic Acid ................................................................................ 72 14. On Islatin ............................................................................................... '13 16. Bpontaneous Decompositim of Gun-cotton ........................................ 25 16. Experimental illustration of the Csmpositian of Ammonia in Lectures ................................................................................................... ra 27. How to exhibit the InflaramabiIity of Ammonk ................................ 78 18. Separation of Cadmium from Copper ................................................... 78 19. Separation of Arsenic from Antimony ................................................ 79 20.Analysisof the Saline Water of Christian Malford. near Chippenham 80 21. Spontaneous Decomposition of Chloride of Lime ............................. 84 22. Bisulphide of Carbon in Coal Gas ..................................................... 85 23. Remarks on the changes of Gutta Percha under Tropical Intluencerr 87 1v CONTENrs. PAGE On the Carbonates of Alumina Ferric Oxide and Chromic Oxide By James Barratt Esq 90 Proceedings at the Meetings of the Chemical Society 92 On certain sources of loss of Precious Metal in some operations of Acsaying By G H Makins 91 On Bibromosuccinic Acid and the Artificial Production of Tartaric Acid W H Perkin P C S and B F Duppa Esq By 102 On the Composition of the Platinocyanides By Edward A Hadow 106 On the Stibetvhyls and Stibmethyls By # B Buckton 115 On Crystalliied Sodium and Potassium By Charles Edward Long 122 On Zinc methyl By J A Wanklyn 124 On some Derivatives from the Olafines By Frederick Guthrie 129 Contribution towards the History of Cinnamic Acid By David Howard 135 Action of Sodium upon Iodide of Methyl mixed with Ether By J.A Wanklyn and F Buckeisen 140 On the Composition of the Aqueous Acids of Constant Boiling Point Henry Enfield Roscoe By 146 Proceedings at the Meetings of the Chemical Society 165 On Organo metalliL Bodies a Discourse delivered to the Chemical Society of London By Dr E Frankland 177 On Acetoxj benzamic Acid an Isomer of Hippuric Acid By GF C Foster 235 On Baudrimont s Protosulphide of Carbon By Lyon Playfair C B F R 9 248 Notice of a New Ammonio chrome compound By J Morland F C S 252 On Circular Polarization a Discourse delivered to the Members of the Chemical Society of London By Dr J H Gladstone F R S 254 On Chemical Anal3 SIS by Spectrum observations By Professors Euchhoff and and Bunsen 270 Contnbutions to the History of the Phosphorus bases By A W Hofmann, F R S {First Memoir) 289 On the Discrepancies in the Statements of Pelouze and F Mohr respecting the Solubility of Gallotannic Acid in Ether By Professor Bolley 325 On the Colonring Hatters of Persian Berries and on certain general relations of Yellow Vegetable Dyes By Professor Bollej 3-07 On a hitherto unobserved source of Paraffin By Professor,Bolley 329 Note of the Action of Chloride of Ethyl upon Ammonia By C E Groves 331 On the Crystalline Form of Metallic'Chromium By Professor Bolley 333 On a New Lead salt corresponding to Cobalt yellow By S D Hayes 335 On the Electrolytic Test for Arsenic and on the presence of that Metal in certain Re agents By Charles L Bloxam 338 On the,Volumetric Relations of Ozone and the action of the Electrolytic Dis- charge on Oxygen and other Gases By Thomas Andrews P R S and P.3 Taite 91 A 344 Proceedings at the Meetings of the Chemical Society 368 Index 373

ISSN:1743-6893    

DOI:10.1039/QJ86113FP001

出版商:RSC    

年代:1861

数据来源: RSC

摘要:

BINIODACETIC ACID. IL-Description of an herntetically sealed Barometer. BY RICIIARD ADIE LIVERPOOL. WHENmounted on an ivory scale this instrument resembles in size and portability a pocket thermometer of the medium or larger class. It is constructed from a piece of thermometer tube in which,in lieu of the spherical or cylindrical bulb formed for a thermometer a cistern is made in the form of the section of a cylinder 1-4inches diameter and 1-10th of an inch thick varying these measures according to circumstances; but generally the bulb has nearly the shape and dimensions of a half-crown. On the top of the tube there is an air cavity similar to that uscd in Dr. Ruth er for d' s registering thermometer. A. The cistern containing alcohol. BB. The tube in which the height corresponding to the barometer is read.*7f-ri 38-7iI 1-11 C. The top of the alcohol column. D. The air-cavity for correcting for temperature. 31 to 27. The figures to represent the height of the column C. with reference to the mercurial column. Sub-divisions between each inch are added so as read off to *02. ADIE ON THE BAROMETER. The influence of change of temperature is got rid of by trid and adjustment of each instrument; so that the expansion of the air in the upper cavity will counterbalance the expansion of the liquid in the cistern. This correction for temperature applies only to the condition OF equal heating of the instrument throughout. When it is well done an instrument is obtained which is ex-tremely sensitive to any change of atmospherical pressure.If dipped in water at tlie temperature of the air the column in the tube immediately rises to show the increase of pressure. When carried from one story of a house to another the change is noticed as the stairs are ascended. In the beginning of last April I put one of the barometers in the corner of the campart- ment of the railway carriage in which I was travelling from Liverpool to Edinburgh where it indicated regularly the extensive changes from the sea level which that line of route contains. The hermetically-sealed barometer which I have found to work best is filled with coloured alcohol; the column in the tube moving through about 1.5 inches for every inch of the mercurial barometer .Filled with mercury instruments corrected for temperature were obtained to move through half an inch for every inch of the barometer; but in point of mobility they were much inferior to alcohol-filled tubes. Filled with ether ail instrument corrected for temperature could not be obtained in combination with delicacy of indication; but if the correction for temperature be dispensed with and a place can be found for the barometer where the changes of temperature are small ether iu an hermetically-sealed tube of the kind described would €urnis11 a most minute measure of changes in atmospheric pressure. A tube filled with water did not act with delicacy from the want of mobility in the fluid. In the hermetically sealed harometer the reading may be much disturbed by uaequal heating when the instrument is held in the hand or the sun allowed to shine on a portion of it. This can in a degree be prevented by the skill of the observer with the inter- position of non-conductors and when carried by holding the instrument suspended by a cord rather than keeping it in the pocket or hand. When the indication has been disturbed by unequal heating it must remain suspended fifteen or twenty minutes before a reliable reading can be made.

ISSN:1743-6893    

DOI:10.1039/QJ8611300007

出版商:RSC    

年代:1861

数据来源: RSC

摘要:

9 1x1.-Action qf Pentachloride of Plzosphorus on Tartaric Acid. BY W. I€. PERKIN, F.C.S. AND B. F. DUPPA,ESQ. IN a paper on malic acid published last April in the Philosophical Magazine we mentioned that Tve were engaged with the study of the influence of pentachloriclc of phoqphorus on Tartaric acid; our time however having been much occupied by other subjects we have as yet been unable to investigate the matter thoroughly but having obtained some peculiar results we take this opportunity of laying them before the Society. On gently heating a mixture of pentachloride of phosphorus arid tartaric acid hydrochloric acid is evolved in abundance and a perfectly liquid mixture is formed consisting of oxychloride of phosphorus and an oil. To obtain the latter in quantity we have found it best to operate in the following manner.One part of pulverized tartaric acid and file or six of penta- chloride of phosphorus are mixed and introrluccd into a retort and gradually heated until perfcctly liquid. The temperature is then elevated and the liquid alloived to distil until it reaches 120";it is maintained at this point and dry air passed through the remaining liquid for five or ten minutes so as to separate as much of the remaining oxychloride of phosphorus as possible. This product which is the chloride of a diatomic acid radical sinks as an oil mlien thromn in water and gradually dissolves. It also dissolves in alcohol forming an ethereal body. If projected into strong aqueous ammonia a violent action ensues chloride of ammonia and a new crystalline compound very soluble in stlcohol and vater being produccd.V7ith phcnylamine this body reacts most energetically. It decomposes partially on being distilled. As mentioned above this substance gradually dissolves i-rtwater. If a considerable quantity is mixed with water it becomes warm and on cooling deposits a white slightly crystalline acid. If exposed to the moist atmosphere for a day or two it becomes a white solid mass. This acid after being well pressed between bibulous paper and recrystallized from water presents itself as tt white almost amor- phous mags but when viewed under the microscope appears as small transparent needles. It is very soluble in water and alcohol has a very acid taste melm when heated and so’lidifizs into r?.crystalline mass on cooling. It is bibnsic. Acid potassiui~4-sdt. This is Ixst obtained by taking a solution of the acid aid di~idirig it irito tvt-o cqual portions neutralizing me nitli carbonate of ptas~i~ilil am1 then adding the otlicr to it. If not too dilute the new salt immediately makes its appearance as a crystalline precipitate which after washing with cold water and recrystallizing once or twice is obtained quite pure. Tt crystallizes in plates. It is more solrtble than the acid tar-tarste of potassium. It contains chlorine. The following carbon hydrogen chlorinc and potassium dcterrninations have been made 1. *3290 of substance gave *3033 of carbonic acid and -0329 of water.11. 2064 of substance ga\re *15G7 of chloride of silver. 111 *69525of substance gave ~271of chloride of potassium. Percentage composition :-Carbon 25.14 Hydrogen . . 1.11 Chlorine . . 18.82 Potassium . 2045 which agrees with the formufa K€I,C&(HCl) 0 as may be seen from the following table :- Theory. EX~. Carbon 8 equiv. . . 48 25.4 25-14 Hydrogen 2 , . . z 1 -05 1.11 Chlorine 1 , . 35.5 18.81 18-82 Potassium 1 , . . 39.2 20*77’ 20*45 Oxygen 8 , . . 6-kO 33.97 188-7 100.00 The neutrnl potassium-salt is crystalline and much more soluble than the former. PENTACHLORIDE OF PIrosrrIoms ox TARTARIC ACID. 11 Siluer-saZt.-On adding nitrate of silver to a solution of either of the above salts a white prccipitate is irnmediatcly formed this when washed with cold water and dried in vacuo over sulphurie acid is fit for analysis.It is very slightly soluble in water. Wlicn viewed under a powerful lens it presents a slightly crystalline appearance. On being heated on platinum foil it decrepitxtes leaving a residue of metallic silver and chloride of silver. The subjoined determinations mere made :-I. 02655 of substance gave -210 of chloride of silver. IT. *%I325 of substance gave -1737'5 of metallic silver and 1I 7 of cliloride of silver. Percetltage composition :-I 11. Silver . . 59.5 . . 5925 Chlorine. . . 9.50 These numbers agree with the formula Ag,,C,(HCl)O as may be seen from the following table :--Theory. Exp. Carbon 8 equiv.. . 48 13.16 ___I Hydrogen 1 , . .1 -27 Chlorine 1 , . . 35.5 9.74 9.50 Silver 2 , . . 216.0 59-23 5937 Oxygen 8 , . . 64.0 17.60 -364.5 100.00 Lead-satt. This salt is obtained by adding acetate of lead to a solution of the potassium salt. It is a crystalline substance dif- ficultly soluble in water. From the foregoing it evidently appears that the new acid has the composition C,(H,Cl)O, and the chloride from which it is derived the formula C,(HCl) O,,Cl,. This acid in composition represents maleic or fumaric acid in which one equivalent of hydrogen is replaced by chlorine; but as it is a very soluble sub-stance it would appear that if derived from either of the above it would be from maleic acid therefore we give it the provisional GLOXAM ON THE DETECTION OF name of chloromaleic acid.We hope shortly to be able to replace the chlorine in this acid by hydrogen and then to ascertain whether it miglrt be vieivecl as a dcriwtive of maleic acid or not because this is important as it may show 11s the relation which tartaric acid bears to malic. The action of pentachlwide of phosphorus may be explained thus :-C,H60, + PC1 = C8H40j0 + PCl,O + 2I-IC1. Tartaric acid. Anhyd. tart. acid. New chloride. This appears to show that tartaric acid represents four molecules of water and that part of the hydrogen and oxygen exist in the same peculiar condition as in glycolic and lactic acid. The formula of tartaric acid appears to be c8Er2041 % O8 We have obtained some wry interesting substances by digesting the bromacetic ethers with sulphocyanides acetates succinates &c. the study of which we are now engaged with.

ISSN:1743-6893    

DOI:10.1039/QJ8611300009

出版商:RSC    

年代:1861

数据来源: RSC

摘要:

GLOXAM ON THE DETECTION OF BV.-On the Application of El'ectrolysis to the Detection of the Poisonous Metals in Mixtures containing Organic Mutters. By CHARLES 1,. BLOXAM. EVERYanalyst is oidy too well amitre of the difliculties which beset the detection of the poisonous metals in mixtures containing organic matters such as the contents of the stomach the solids and fluids of the body arid articles YJ€ food. The process which I belime most chemists now generally adopt in such cases consists in disintegrating and partly oxidising the organic matters by the aid of a mixture of hydrochloric acid and chlorate of' potmsa and afterrnards precipitating the filtered sof-ution by hydrosulphuric acid the arsenic acid having been previously reduced by means of sulphurous mid.In most cases the solutioii obtained by treatillg the organic POISONOUS METALS BY EEECTRO TAP SIS. matters with hydrochloric acid and chlorate of potassa affords n precipitate on the passage of hydrosulphuric acid whether any of the metals forming insoluble sulphides be present or not this precipitate is generally of a dark greyish brown colour; is very difficult to filter and wash; and interferes in a most disagreeable manner with the application of the tests for those metals which are precipitable by hydrosulphuric acid froni their acid solu+' "ions. It is therefore in the highest degree desirable to adopt some more satisfactory method for separating the nietals of the hydro- sulphuric acid group from orgaPric mixtures.Two of these metals arsenic and antimony may it is true be readily extracted in the form of gaseous hydrogen compounds by Marsh's process ; and the objections to this course haw been so often commented on that when I repeat some of the most im-portant of them here it is only that I may plead a fair excuse for submitting this communication to the society. The occasional prcsence of arsenic in the snlphuric acid and of both arsenic and antimony in the zinc has ahys been a serious objection to the use of Marsh's test; and although the hydrogen evolved at the beginning of the experiment may be carefully examined before introducing the suspected liquid the operator always proceeds upon the assumption that the zinc is perfectly homogeneous and that it is impossible for arsenic or antimony which had eluded detection in the first portion of hydrogen evolved to become apparent nhcn tlic rnms of the zinc has entered into solution.When liquids holding organic matters in solution are intro- duced into Marsh's apparatus the frothing occasioned by the viscidity of the mixture often gives rise to very serious inconve- nience; for although it may generally bc checked by the addition of alcohol itssometimes gets quite beyond the control of the operator and the experiment is entirely lost. But the most serious objection is that the liquid which has been examined by this method for arsenic and antimony cannot be ex-amined for any other metals on account of the presence of so large a quantity of sulphate of zinc a consideration of very grave importance in cases where the qnant$y.of the suspected matter is small. The ohjections to the convenient and delicate process of Reinsch rest upon similar grounds and are even more readily admissible. The deteetion of the poisonous metals by the decomposing action of the galvanic current is I think free from these objec- tions and so minute quantities of the poisonous metals may be detected by this method of testing that it may safely be relied upon in most cases of chernico-legal investigations.* The first experiments were directed to ascertain whether minute quantities of the most important poisonous metals could be easily detected by electrolysis in solutions free from organic matters Detection of Arseniic.The apparatus which was at first employed consisted of an ordinary U-tube one limb of which was closed with a perforated cork through which passed a tube for the escape of the hydrogen and a platinum wire connected with the zinc extremity of a Grove's battery of five cells; to this wire %asattached a platinum plate measuring ahout 2 inches by 9inch which was thrust down almost to the bottom of the U-tube. The other limb of this tube mas left open for the escape of the oxygen and contained a similar platinum plate connected with the platinum extremity of the battery. The tube which carried off the hydrogen was connected with a straight tube of hard glass drawn out to a long open point and heated to redness at the shoulder in order that any arseniuretted hydrogen might be decomposed in passing through it.At the commencenient of each experiment the U-tube was charged with a fluid ounce of diluted sulphuric acid (containing one measure of oil of vitriol and four measures of water) and as soon as the closed limb had become filled with hydrogen the drawn-out tube was heated with a spirit-lamp for 15 minutes in order to ascertain that no deposit of arsenic was obtained from the sulphuric acid alone. The solution to be examined for arsenic mas then introduced into the closed limb by withdrawing the cork for an instant and the experiment continued. The U-tube was immersed in a vessel of water to prevent the temperature from rising too high during the passage of the currc.n t .*Eefore submitting this communication to the So<Iiety the author was not aware of the existence of XI. Gaultier de Claubry's admirable paper upon this method (J. Pharm. [3],xviii 125; a6str. Chem. Soe. Qu. J. iii 162). This chemist hovrever appears lohave relied upon the precipitation of the arsenic not upon its evolution in the form of arseniuretted hydrogen. POISONOUS JXETALS BY ELECTBOLYSIS. The quantity of arsenic employed for each experiment was determined by carefully measuring out a standard solution of arsenious acid. Three expe iments made with aqwous solutions containing & & and T+m grain respectivcly (corresponding to W6 %076 and 90076 grain of mctwlIic arsenic) proved that the arsenic could be readily obtained as in Marsh’s test in the form of a brilliant metallic crust in the narrow point of the tube about half an inch beyond the heated portion.In order to ascertain whcther the presence of alcohol would interfere with the action of the test in case it might become necessary to add it in order to prevent frothing an ounce of dilute sulphuric acid and a drachm of alcohol were introduced into the apparatus and electrolpsed until the tubes were full of hydrogen ; on heating the evolution tube a faint odow resembling inercaptan was perceived but there was not the slightest deposit. Oil iiitro-ducing grn. of arsenious acid a most satisfactory mirror was formed in the tube in less than five minutes and a decidedly arsenical odour like that of alkarsin proceeded froin the extremity of the evolution tiibe.In subseqiient experiments as in this I found that the presence of alcohol appeared to facilitate the production of an arsenical crust and that the arsenical odour aflbrt’led a valuable confirmation with respect to the presence of arsenic. The method was then tested ax to its applicability in cases where the a&enious acid is mixed with large quantities of organic matters. A nlixture was prepared containing about 3. oz. lean meat 1oz. bread 1+oz. milk and 3 oz. white of egg beaten to a pretty uniform pulp in a mortar. To this mixture was added an aqueous solution of +&grain of arsenious acid. The whole was then mixed with 1 fluid oz. of hydrochloric acid and 4 08. of water; this mixture was digested in the water-bath for 15 minutes filtered and the clear solution evaporated on the water-bath to 3+ fluid oz.of a dark brown viscid liquid. On introducing one-fourth Df this (= 0.025 grn. .As03) into the decomposing tube it frothed up very much but was immediately checked by the addition of a draclim of alcohol and a deposit of arsenic was almost immediately formed in the heatcd tube. A repetition of the experiment gave a siinilsr result but about 15 minutes were required for the formation of a good arsenical mirror. BLOXAM ON THE DETECTION OF In a third trial one-sixth of the solution mas talien ( =0.017 grn. AsO,) with a like rcsult the odour of alkarsin being also very distinct. A fresh organic mixture was poisoned as before with & gm.of arsenious acid and treated in thc same manner being finally evaporated to 2 fluid oz. One-tenth of this opaque brown liquid (=0.01 grn. AsO,) gave a very distinct mirror in less than 5 mintites attended with a strong arsenical odour. One-hundredth of this liquid (= 0.001 grn. AsO,) also gave a very distinct mirror and dour in lo minutes. Since arsenic is sometimes contained in organic mixtures in a form (e.g. that of sulphide of arsenic) not readily soluble in hydro- chloric acid it became necessary to ascertain whether the solu- tion obtained by adding chlorate of potassa together with the acid would give the indication of arsenic by this method of testing for such a solution would of course contain the arsenic in the form of arsenic acid.The experiments made to determine this point proved that small quantities of arsenious acid (& gm.) could not be detected by this test after boiling with hydrochloric acid and chlorate of potassa unless the solution had been digested with sulphurous acid in order to reduce the arsenic acid The behaviour of tersulphide of arsenic was then examined. One-tenth grn. of arsenious acid was precipitated as sulphide the latter dissolved in hydrochloric acid and chlorate of potassa and the solution evaporated on the water-bath till the odour of chlorine was no longer perceptible. One-half of this liquid (= 0*85grn. AsO,) was introduced into the decomposing tube but no indication of arsenic was obtained in 15 minutes.The other half was saturated with sulphurous acid gas digested for some time in the water-bath and evaporated till the odour of sulphurous acid had disappeared. On subjecting it to the electro- lytic test a distinct mirror of arsenic was obtained in 10 minutes. One-tenth grn. of tersulphide of arsenic (= 0.06 gm. As) dissolved in diluted sulphide of ammonium was added to a mixture of articles of food similar to that previously used with the addi- tion of 3 oz. of strong ale. The mixture was digested on a water-bath with '4_ oz. of hydro-chloric acid and 3 02;. of water chlorate of potassa being added in small quantities until a thin homogeneous fluid was obtained; the POISONOUS METALS BY ELECTROLYSIS. 1’1 filtered liquid was digested for half an hour with a large excess of a saturated solution of sulphurous acid then evaporated on the water-bath to about oz.One half of this very nasty brown syrupy liquid mas mixed with a drachm of alcohol and introduced into the decomposing cell. The want of mobility in the liquid somewhat retarded the evolution of gas but in less than 15 minutes the arsenical deposit commenced and in 30 minutes a very beautiful mirror was obtained. In one or two of the experiments with orgnnic mixtures minute quantities of arsenic had escaped detection without any assignable cause; and I was therefore led to make some experi- ments to ascertain whether any influence was exerted by a varia-tion in the amount of hydrochloric acid present in the solution.A standard solution was prepared by dissolving 1 grn. of arsenious acid in 1000 grns. (by measure) of hydrochloric acid. 10 grns. of this solution (-& grn. AsO,) mixed with 20 gras. of hydrochloric acid gave a very distinct crystalline deposit of arsenious acid in the tube but no sublimate of metallic arsenic dthough a deposit of arsenic was formed upon the negative plate. 100 gms. of the solution (& gm. AsO,) mixed vith 200 grns. of hydrochloric acid gave a similar result. 50 grns. of the solution (Agrn. AsO3> diluted with 400 gms. of water behaved in the same way. In these cases the arseniuretted hydrogen appeared to have been converted into terchloride of arsenic which was decomposed by the aqueous vapour on passing the heated portion of the tube with formation of arsenious acid.Finding that in these experiments the smell of chlorine mas distinctly perceptible at the end of the evolution tube and believing that the chlorine disengaged at the positive pIate diffusing itself through the liquid caused the decomposition of the arseniuretted hydrogen I employed another apparatus consisting of two decomposing cells separated by a diaphragm of vegetable parchment. In this form of apparatus 10 grns. of the solution of arsenious acid in hydrochloric acid (= Thgrn. AsO,) mixed with 1%) grns. of hydrochloric acid and introduced into the negative cell of the apparatus (the latter having been charged as usual with a fluid ounce of dilute sulphuric acid) gave a beautiful mirror of arsenic in two minutes.VOb. XIII. c BLOXAN ON TRE DETECTION OF A mixture of articles of food to which -&grn. of arsenious acid had been added was digested with a fluid ounce of hydro-chloric acid and three or four ounces of water; the filtered solu- tion was evaporated down to one ounce upon the water-bath and one-tenth of it (= &grn. AsO,) was introduced into the apparatus with Q drm. alcohol. In less than fifteen minutes a very distinct arsenical mirror had been formed. The apparatus which was ultimately found most suitable for the detection of arsenic by electrolysis consisted of a two-ounce narrow-mouthed bottle the bottom of which had been cut off and replaced by a piece of' vegetable parchment tightly stretched over it and secured by a ligature of thin platinum wire (even vulca- uised caoutchone is speedily corroded) The bottle was furnished with a cork carrying a small tube bent at right angles and connected with the drawn-out reduction tube by a caoutchouc tube; through this cork passed a platinum wire bent into a hook inside the bottle for suspending the negative plate.The bottle was placed in a glass of such a size as to leave a small interval between the two and this glass was allowed to stand in n large vessel of cold water; an ounce of dilute sulphuric acid wa9 introduced into the apparatus so as to fill the bottle and the outer space to about the same level the positive plate being immersed in the acid contained in this outer space. When the bottle had become filled with hydrogen the shoulder of the reduction tube was heated to redness during fifteen minutes to ascertain the purity of the sulphuric acid and the liquid to be tested was intro-duced into the bottle by means of a pipette the cork being removed for an instant; n drachm of alcohol was afterwards introduced by the pipette to prevent frothing.In the following cases the arsenic mas most satisfactorily detected in this apparatus the evidence of its presence being three- fold and resting firstly upon the formation of the characteristic arsenical mirror; secondly upon that of a small shining ring of crystalline arsenious acid slightly in advance of the mirror ; and thirdly upon the development of the peculiar alliaceous odour. &grn.arsenious acid in hydrochloric solution. 1 -, aqueous solution. I0000 ,Y 1 I3T 9 dissolved in 120 gms. hydrochloric acid. 200 A 9 >> 115 , ?J 1 1000 1 IJ 120 9 91 and 240 grns. water POISOX'OUB METAL8 BY ELECTROLYSIS. These experiments were repeated with the same results. Experiments were then made upon organic mixtures containing arsenic which were boiled with hydrochloric acid and chlorate of potassa the arsenic acid being afterwards reduced to the arsenious by digesting with sulphurous acid or better with a few drops of a strong solution of bisulphite of soda. By this process TiT grn. and even -i-GT5 grn. of arsenious acid could be detected in an organic mixture with the greatest ease and certainty. If the sulphurous acid be not entirely expelled after the reduc- tion a little tersulphide of arsenic is deposited in advance of the metallic crust.The following process appeared to me the most trustworthy for the detection of minute quantities of arsenic in articles of food The solid matters are reduced to B pretty fine state of division mixed with enough water to form a thick grnel and digested in a a dish placed on a water-bath with about +oz. of hydrochloric acid for an hour powdered chlorate of potnssa being occasionally added as directed by Fresenius and von Babo until the organic matters are disintegrated when the liquid is filtered off and evaporated to about an ounce upon the water-bath. The browu fluid thus obtained is poured into a flask and a few drops of a strong solution of bisulphite of soda are added to it until it smells strongly of sulphurous acid; the flask is then heated in a water- bath until this odour has disappeared when the solution is mixed with at least an equal volume of water and introduced into the apparatus arranged and charged as above a little alcohol being poured upon the top.The operation should be continued for half an hour before the absence of arsenic is inferred. The advantages which appear to me to belong to this mode of testing are that it involves the use of a metal which has never been known to contain arsenic; that the very same portion of sulphuric acid which is employed throughout may be subjected to the test for any length of time before the suspected liquid is introduced ;that the evolution of gas is uniform throughout the experiment and is always so slow that no dread of losing the arsenic need assail the mind of the operator ;that the experiment may be interrupted for any length of time by breaking the contact with the battery without the least injury ;that the foulest liquids can be as readily tested as those which are perfectly clear ; c2 BLOXAM ON THE DETECTION OP and that the same portion may afterwards be further tested by any other process.The importance of this last consideration was fully exemplified in some of the early failures before I was well acquainted with the test for I always succeeded in detecting the arsenic in the same portion of the liquid by Marsh's test.It is evident moreover that this operation enables us to detect minute quantities of copper antimony mercury and bismuth if they be present in the solution. On considering the detection of the other poisonous metals in this way it is obvious that lead must be altogether excepted on account of the insolubility of its sulphate. Silver must also be omitted where hydrochloric acid is the solvent; and baryta of course would not be expected to answer. The remaining important poisonous metals antimony copper mercury bismuth and zinc were therefore tried bismuth being included on account of the medicinal use of its compounds. Detection of Antimony. 1 gm. of tartar-emetic (= 0.36 grn. Sb) dissolved in water was introduced into the decomposing cell.A mirror of antimony was formed just at each margin of the flame which heated the reduction tube and a copious deposit of antimony was formed on the negative plate. -& grn. of tartar-emetic (= 0.036 grn. Sb) gave only a slight wliite incrustation and no mirror in the reduction tube. The black deposit of antimony on the negative plate was dissolved by heating the Patter with a few drops of yellow sulphide of ammo-nium; on decomposing this solution with acetic acid a very distinct orange precipitate of tersulphide of antimony was obtained. A mixture of articles of food was mixed with -&grn. of tartar-emetic and treated exactly according to the process above described for the detection of arsenic. There was no appearance of a metallic deposit in the reduction tube in twenty minutes; but there was a thick coating of antimony upon the negative plate which was dissolved by yellow sulphide of ammonium.A portion of' this solution when evaporated in a watch-glass on the water-bath left a residue having a decided orange colour. A second and even a third coating of antimony was obtained POISONOUS METALS BY ELECTROLYSIS. by again immersing the plate for a few minutes and when the film was very slight it was at once identified by the orange stain produced when a drop of sulphide of ammonium was evaporated upon it. The result of the two last experiments which was fully con- firmed in all subsequent trials is a very important one its showing that minute quantities of antimony are not nearly so likely to be mistaken even for n time for arsenic in the electrolytic as in Marsh’s test and this seems attributable to the superior electro- positive tendency of antimony which ciisposes it to precipitate more readily upon the negative plate.In no case have ]I failed to detect antimony in this way. The following mode of proceeding may be recommended for the detection of the poisonous metals by electrolysis :-The mixture which may of course have been previously examined for organic poisons by the usual methods is digested on a water-bath with so much water hydrochloric acid and chlorate of potassa as may be required to disintegrate the solid portions and to render the liquid capable of filtration ; the filtrate is evaporated on the water-bath to a small bulk and digested in a flask with a sufficient quantity of solution of bisulphite of soda to impart a strong odour of sulphurous acid.The solution is heated in the water-bath until the odonr has disappeared and is once more concentrated if necessary by evaporation. It is then diluted with a volume of water equal to at least twice that of the hydro- chloric acid present and introduced into the decomposing cell enough alcohol being poured upon it to prevent any inconvenient frothing. The passage of the current having been continued for about an hour the negative plate is withdrawn washed and boiled in somewhat dilute yellow sulphide of animonium for a minute or two. This solution is then evaporated in a watch-glass placed on the water-bath and the orange residue of sulphide of antimony identified by the usual tests.The platinum plate having been again washed is boiled in a few drops of concentrated nitric acid to which a drop of dilute hydrochloric acid should be added to dissolve the sulphide of mercury. The acid solution is bofled down in the test tube to a small bulk and mixed qith an excess of ammonia when the presence of copper will be rendered evident and the teroxide of bismuth will be precipitated together with a little arnmonio- chloride of platinum. This precipitate when FRANKLAND ON THE COXPOSITION OF dissolved in liy drochloric acid evaporated and largely diluted will present the indication of bismuth. Tlie filtered ammoniacal liquid acidulated with hydrochloric acid and boiled with clean copper affords the usual evidence of the presence of mercury.Of the metals above mentioned mercury was found to be the only one which interferes with the detection of arsenic. If this metal be detected the liquid taken from the decomposing cell (or a fresh portion of the origiiial hydrochloric solution) may be distilled according to Dr. Odling’s recommendation in order to separate the arsenic from the mercury. The residue may still if the analyst deem it expedient be further dealt with by incineration or otherwise for the detection of other niekals.

ISSN:1743-6893    

DOI:10.1039/QJ8611300012

出版商:RSC    

年代:1861

数据来源: RSC

摘要:

FRANKLAND ON THE COXPOSITION OF V.-On the Compositionof Air from Moat Blanc By DR. E. FRANKLAND, F.R.S. THEgreatly increased perfection of gasometric analysis and the numerous minute investigations made by Regnaul t Bunsen and others during the past ten or fifteen years have rendered our lcnowledgc of the composition of atmospheric air exceedingly complete as far at least as its two chief constituents are concerned. The earliest analyses of air led chemists to believe that the rela- tive proportions of these constituents were liable to very consider- able fluctuations. As the processes employed however became more accurate these discrepancies gradually disappeared ;until at length carefully conducted experiments showed an apparent uni-formity in the composition of samples of air taken from the most widely different localities; but it remained for subsequent and far more delicate methods of research to demonstrate that notwith- standing these apparently accordaxit results the composition of the atmosphere does in reality exhibit certain fluctuations confined however within very narrow limits The first series of experiments belonging to the latter category and which may be said to have first established the variability of the percentage of atmospheric oxygen are those of Bunsen made AIR PROM MONT BLANC.upon samples of sir collected at Marburg on ten different days and exhibiting when freed from carbonic acid a percentage of oxygen varying from 20.Y73 to 20.840 whilst no two analyses of the same sample differed more thm -031 per cent from each other.Then followed a most elaborate series of determinations by Regnault begun in December 1847 upon the air of Paris and continued in January 1848 The variations in the percentage of oxygen here observed were in December 1847 from 20.90 to 2l*SO,and in January 1848 from 20.89 to 20.99. Lewy collected air near the surface of the sea on the 18th December 1847 at 3 P.M. in lat. 21" 9' N. and long. 42' 52' W. of Paris temperature 24"C. and found it to contain :-Nitrogen . 78*886 Oxygen . . 21.060 Carbonic Acid . *054 Another specimen collected December 4th 1847 at 3 A.M. in la&47" N. and long. 13' W. temperature 13"C. contained :-Nitrogen . 79.006 Oxygen .20.961 Carbonic Acid . . *033 r__-100-000 A Iarge nnmber of analyses by the same ehemist*demonstrate that the air near the surface of the sea contains about2 the same proportion of carbonic acid as that resting upon the land and that the sea air is richer both in oxygen and carbonic acid by day than by night; a fact which he explains by assuming that dissolved air is liberated during the day from the heated surface-layer of the ocean such dissolved air being as is well-known much richer than atmospheric air in the two gases just named. Lem'y also made a very extended series of analyses of air collected at New Granada and Bogota during thc dry and rainy seasons. The mean of eleven analyses of air from New Granada gave :- FRANKLAND ON THE COMPOSITION OF Nitrogen .78.946 Oxygen . . 21.014 Carbonic Acid . . oo40 1oo'ooo Analyses of air from Bogota collected during the dry and rainy seasons gave the following mean numbers :-Dry Season. Rainy Season. Nitrogen . . 78.932 78.966 Oxygen. . . 21.022 20.996 Carbonic acid . -046 *038 100~000 100~000 On some occasions the air of New Grenada was found to con-tain as much as 049 per cent. of carbonic acid on which occasions the percentage of oxygen fell as low as 20.331. This abnormal composition is ascribed to volcanic eruptions and extensive confla- grations. In nearly all cases Lemy seems to have found that an increased amount of ca~bonic acid in the air was accompanied by an increase in the percentage of oxygen.Messrs. €€.and A. Schlagintweit determined by weighing the amount of carbonic acid in the air at great elevations in the Eastern Alps by absorption with p6tash; but as the increase in weight of the potash apparatms was only from 3 to 6 milligrammes in each experiment and as the two weighings were made at intervals of nearly two months these detcrrninations can only be regarded as approximative. Messrs Schlagintweit found the volume of carbonic acid to vary from #032 to *058per cent Up to an altitude of 11,043 feet they found a gradual increase of carbonic acid but at tliis elevation they conceived that a constant maximum was arrived at. In some later experiments on the air of Monte Rosa at heights varying from 13,374 to 13,858 feet the same experimenters found a mean percentage of carbonic acid equal to *079and a maximum of *095.In the year 1852 M. Itcgnault published an extensive series of determilzatioris of the percentage of oxygen in samples of air AIR FROM MONT BLANC. 25 deprived of carbonic acid from different localities. The following is a condensed summary of his results Percentage of Oxygen. 100 specimens from Paris and neighbourhood a (1848. . 20.913 20.999 9 ?> , Lyons Montpeliier & St. Martin-aux-Arbres . 20.918 20.966 30 , , Berlin (1848 & 1849) . 20.908 20.998 >, , Madrid (1848) 20.97 6 20,982 23 2 , Geneva Mont Sa%ve and Mont Buet . 20,909 20.993 15 1 , Toulon the Mediterra- nean and Algiers . 20.912 20.982 5 , taken during a voyage from Liverpool to Vera-Cruz .310.918 20-965 1 , from Guallalamba South Ame- rica . 20.960 2 9 , the summit of Pichincha (15,924 feet) -. 20,949 20.988 In this investigation a few remarkable deviations from these normal amounts of oxygen were observed vix. :-Percentage of Oxygen. Air collected in the I-farbour of Algiers June 5th 1851 . . 20.42 20.395 Air from Bay of Bengal February lst 1849 . 20.46 20-45 Air from Ganges March 8th 1849. Tempera-ture 35"C. foggy weather much decompos- ing organic matter in the water. Corn-mcncement of an outbreak of cholera . 20.390 20.387 It would be interesting to know how far these results were really abnormal as regards the relative proportions of oxygen and nitro- gen since it is not improbable that the apparently small per- centage of oxygen indicated mas in reality due to the presence of gaseous organic matters in larger quantity than usual; the ignition of these with excess of hydrogen in the mode adopted in these analyses would have the eEect of converting the carbon of such organic matters into carbonic oxide thus diminishing the contraction of volume on explosion and consequently the apparent FRANKLAND ON THE COMPOSPTION OF percentage of oxygen.Should such abnormal specimens of air be again encountered it mould be desirable subsequently to the analysis made in the usual manner to igiiitc other partions of them with an equal volume of mixed electrolytic gases so as to convert the carbon of any organic matter that might be present into carbonic acid which could then be estimated in the usual manner by absorption with potash.Dr. Miller examined air collected during a balloon ascent in August 1852 at a height of 18,000 feet and also a sample collected near the surfme of the earth at the same time with the following results Air from altitude Air near the of 18,000 feet. earth. Percentage of Oxygen . . 20.88 20-9.2 After these numerous and minute analyses establishing as they do with few exceptions the slight but still undoubted variations in the relative proportions of the tmo chief atmospheric gases any further contributions to this particular branch of our knowledge can only be of comparatively small value. Nevertheless as an apportunity was afforded me for collecting specimens of air whilst accompanying Dr.Ty n dall during the past summer in his ascent cf Mont Blanc for the establishment of thermometric stations I did not regard a fern further experiments upon air from great altitudes as entirely SLI~CX*~~LIOUS ;since the discovery of the causes determining the variations in the composition of the atmosphere will probably only be arrived at by the accumulation of vast numbers of obscrvations made at VW~QUSpoints at and above the earth’s surface. It ~ill also bc perceived on reference to the various analytical results above given that with the exception of XI. Lemy no experimenter lzas made contemporaneous determi- nations of the three chief gaseous constituents of the air; and I was thcrcfore anxious if possible to render these samples avail- able for the determination of carbonic acid as well as of the two other chief gases.The very minute changes of volume which the instrument I use for gaseous analysis is capable of registering led me to hope that it might not be impossible to make direct determinations of carbonic acid in the few cubic inches of air which are usually sealed up for analysis ;and a number of estimations of the carbonic acid in air collected. at St. Bartholomcw’s Hospital proved that All% FROM HONT BLANC. this gas can be thus estimated by absorption with caustic potash. Such an amount of air was taken for each determination as was capable of supporting a column of mercury from 600 to 800 millimeters high which rendered any diminution of volume to the extent of about T&T part distinctly appreciable.The following results were obtained those on "the 26th of January being seveii successive determinations extending over about three hours Percentage of Carbonic Acid. . -042 . 964 . ,077 . *098 . 0087 ._. . . *098 .i . *085 . *098 * -110 * -101 Although it cannot be doubted that there are other methods by which carbonic acid can be more minutely and accurately determined whenever they can be carried out with the usual conveniences of a laboratory at hand yet it is very questionable whether any of these processes em rival this purely eudiometrical one in cases where the operations have to be performed in the midst of all the inconveniences attending an experimenter at great altitudes.Any such estimations involving the weighing of potash tubes at intervals of several days or even weeks are obviously not worthy of implicit confidence. ln the above mode of determination the actual change of volume self-corrected for temperature aqueous vapour &c. being actually observed by the operator aD error exceeding -01 per cent. is probably rarely or never committed. Iu the following analyses of air from &font Blanc the carbonic acid was absorbed by a single drop of concentrated solution of caustic potash and the oxygen was then determined by exploding the residual gas with excess of electrolytically prepared hydrogen. Specimen collected at the Grands Mulets (altitude 11,000 feet) August 20th 1859 at 6.45 P.M Wind north hail falling but a moderately clear sky FRANKLAND ON THE COMPOSITION OF Estimation of Carbonic Acid.I Obs. vol. Temperature C. Air used . . . 539*5 5.0' After absorption of carbonic acid . 538.9 5.0" Estimations of Oxygen. 11. Obs. vol Temperature C. Air used . 0 . 290.8 5.2" After admission of hydrogen 4865 5*2O After explosion 8 . . 304.9 5*2* 111. Obs. vol. Temperature C' 0 Air used . . . 248.7 5.2' After admission of hydrogen . 443% 5-2' After explosion . 288.7 5.2" Percentage Composition I. 11. 111. Mean. Nitrogen . .. 79096 79.124 79.110 Oxygen . .. 20.793 20.765 20.779 D.Carbonic acid 0.111 .. *111 100*000 Specimen taken at the summit (altitude 15,732 feet) August 2lst at 8.45 A.M. Wind north ;weather bright and sunny; air filled with particles of snow whirled up by the wind. Estimation of Carbolzic Acid. Obs. vol. Temperature C. Air used * 4 . 326.1 5.2' After absorption of carbonic acid . 325-9 5*2O A133 FROM MONT BLANCo Estimations of Oxygen. Ob,s. vol. Temperature C. . . . 166.8 5.3O Air used . After admission with hydrogen . 273.0 5*3O After explosion . . '168.1 5*3O 111 Obs. vol. Temperature C. . 159.9 5*3O Air used . . 0 After admission of hydrogen. . 302.7 5*3O After explosion . . . 202.7 5*3O Percentage Composition. I. Is. III. Mean.Nitrogen .. 78.989 78.988 78.989 Oxygen . .. 20.950 20.951 20.950 Carbonic acid @061 .. .. -061 100*000 Specimen collected at Charnonix (altitude 3000 feet) August 23rd at 2 P.M. Wind north; sky clear. &stirnation of Carbonic Acid. L. Obs. vol. Temperature C. Air used . . . * . 474.1 5*4O After absorption of carbonic acid . 473.8 5*4O Estimations of Oxygen. 11. Obs. vol. Temperatare C 8 8 0 Air used . 255.6 5*Oo After admission of hydrogen * . 456.8 5*0° After explosion . . 295.5 5*Oo 111. Obs. Val. Temperature C. Air used . . 217.4 5.0" After admission of hydrogen . . 377.3 5*0° After explosion . . 241.1 5 *Oo Percentage of Copposition. I. 11. 111. Mean. Nitrogen *. 79.0-15 79.007 79.056 Oxygen ... 20-892 20.870 20.881 Carbonic acid 0063 .. .. 0063 So far as the nitrogen and oxygen are concerned the composi- tion of these samples of air falls within the limits of variation noticed by former experimenters ;but although the comparatively high percentage of carbonic acid at the Grands Mulets confirms the observations of the Messrs. Schlagintweit as to the presence of a larger amount of this gas at great elevations yet the diminu- tion of the quantity to abaut the normal amount upon the summit shows either that this gas attains a maximum at a height of abotd 11,000 feet and again diminishes above this altitude or as is much more probable the percentage of' carbonic acid is generally but not invariably greater in the higher regions of the atmosphere.These results also exhibit a correlation between atmospheric oxygen and carbonic acid for when the one increases the other diminishes,-a fact tvhich will be better seen from the following comparison :-Percentage of Mean percentage of oxygen, carbonic acid. in air free from carbonic acid Grands Mulets . . -111 20.802 Summit . . -061 20,963 Chamounix . . -063 20.894 This result if it be confirmed cannot be regarded as altogether unexpected when we consider the effects of vegetation combus- tion and respiration upon the coiistituents of the atmosphere ; but both this and the comparative amoqnt of carbonic acid at great altitudes are problems the solution of which must be left to future and more extended inquiries.

ISSN:1743-6893    

DOI:10.1039/QJ8611300022

出版商:RSC    

年代:1861

数据来源: RSC

摘要:

31 V1.-On ReJiniiig Gold when alloyed with Tin or Antimony so us to render it $t for the purposes of Coinage. BY ROBERTWARINGTON. TOWARDS the latter end of the year 1857 I received from the Australian Bank a specimen of bar-gold for analysis mhieh was stated to have been obtained from the quartz-crushing process. On the exterior or what had been the surfaces of the original bar it presented the general appearance of a golden hue though perhaps an experienced and critical eye might have considered it a little paler than pure gold. Interiorly or on the broken surface however it had a crystalline structure of a greyish yellow colour. It was very brittle and rotten and by analysis yielded the following results on the 100 parts. Gold . . 92.50 Silver .. 4%0 Tin . 2.00mitli a trace of antimony Copper . . 0'75 99.75 Loss . 0.25 __.- 100*00 I have been informed that numerous bars of this white and brittle gold had arrived in this country from Australia and had caused much trouble and annoyance to the refiners rnelters and also to the Mint officers as it will be evident that the nature of the alloying metals is not rendered apparent in the ordinary mode of assay by the processes of cupellation and quartation they being oxidized dissolved and carried into the crtpel with the lead; and that therefore in the after larger operations of melting when the gold passes forward for the purposcs of coinage the existence of the tin and antimony not having been discoverd is iiot provided for and consequently from the brittle nature of the alloy the subse- quent processes of rolling to which it has to be subjected are rendered impracticable I am informed that about 47,000 ounces of gold bars have in this condition been returned to the Bank of England authorities from the Mint as unfitted for the purposes of coinage.WARINGTON ON REFINING GOLD WHEN A short time after the foregoing examination was completed and reported on I received another specimen of this brittle gold for analysis through other parties. This seeorid sample presented somewhat the same appearances both externally and internally as the one just described being perhaps a little whiter in its colour and more rotten or friable in texture. It yielded by analysis on the 100 parts :- Gold .. 93.88 Silver . 2.20 Antimony . . 2.28 Tin . . 1.40 Copper . traces 99.68 Loss . . 0.32 -100 An interesting question arises from the above results as to the origin of these injurious alloying metals ; do they occur associated with the gold or are they introduced during the melting process ? As regards the first we know that in stream works gold and oxide of tin are commonly found associated as is the case in Ceylon in Cornwall and other districts. We know also that considerable quantities of stream-tin are brought from Australia. The presence therefore of that metal in small quantities as an alloy in the re-sulting gold bars might be almost anticipated. But this view of the case does not account satisfactorily for the other alloying metals found in the second analysis particularly the antimony.My own impression derived from a careful examination of the specimens and the foregoing results is that they are introduced during a rough process of refining through the employment of sulphuret of antimony and that for want of efficient management the operation has been imperfectly carried out;. The use of sulphuret of antimony for the purpose of refining gold and raising its standard is so well known that I need hardly dilate upon it; suffice it to say that if successfully applied it converts the iron zinc tin &c. that may be present and much of the silver into the form of sulphurets which float in their melted state upon the surface of the gold; a portion of the antimony at the same time alloying with that metal.This antimony should of course be afterwards removed by a second ALLOYED WITH TIN On ANTIMONY. operation.* From a specimen which has since come into my possession it will be seen that the particles of gold dust have been so imperfectly melted before running into bars that many of them are still visible in their flattened and rounded forms and must therefore have remained suspended in the melted alloy. I feel that this explanation of the source of the alloying metals is therefore to some extent substantiated as a want of a sufficiently high and continued heat would leave the gold very much in the state above described. On delivering the report of this second analysis to the parties from whom I had received the sample they were anxious to know if I could suggest to them a method by which these injurious alloys could be removed and the gold rendered capable of being rolled or hammered without at the same time greatly increasing the expense of the operations or entailing a loss of the gold.I was in consequence induced to turn my attention to the effecting of this desirable object. The proper resolution of this problem required a little consideration inasmuch as although it was evident that it must be accomplished by a process of oxida- tion to burn out ps it were the antimony and tin; yet it was also necessary that the oxygen should be applied to the alloyed gold while the metal was in its fluid state and also that the oxidiz- ing agent should not part with its oxygen simply by the high temperature to which it would be subjected.Nitrate of potash I was informed had been suggested tried and failed although a very large percentage had been used; experi- ments in that direction were therefore considered unavailable and my attention was consequently turned to the employment of metallic oxides having a weaker affinity for oxygen at these high temperatures than the metals which it was required to remove from the contaminated gold. After a few experiments all of which were more or less mccess- ful I succeeded in obtaining the desired result and submitted for the consideration of the parties concerned a simple proccss which from their liberality I mas enabled at the time to corn-municate to several friends interested in such matters and which I also desire now to lay before the members of the Chemical Society.The process consists in the employment of oxide of copper about 10 per cent. of which is to be added * Since making this communication I have been informed that sulphate of antimony also sometimes occurs in association with native gold in Australia. VOL. XIII. I) WAWNGTOPr’ ON REFIXING GOLD. to the alloyed gold with the addition of a small quantity of borax and the whole maintained in a well fused state for about half an hour. The result is a pd’ectly malleable gold containing a small percentsgc of metallic copper and wcll fitted for the purposes of coinage. The proportion of oxide of copycr used must of course greatly depend on the percentage quantity of the oxidable metal requiring to be removed; but I believe from the specimens which I have worked on that it never need exceed the 10per cent.Oxide of manganese might be employed to effect the same purpose; but I found that the fuvibility of the oxide of copper and its powerful fluxing properties rendered its actioti much more efficient and complete from its flowing continually over the surface of the molten gold and thus thoroughly oxidizing and removing the tin and antimony from their combination. As thus conducted the resulting alloy should a!mays be better than standard unless the baser metals occur in very large proportion. By the action of nitro-hydrochloric acid upon these samples of alloyed gold the resulting solution deposited on cooling beautiful crystals of chloride of silver; and I may be allowed here to mention a very curious case of the same kind but to a much greater extent which was brought under my notice some time since by the late Mr.Maurice Scanlan.It appcared from his statement that he Bad been requested to obtain the gold from a beautifully wrought and small sized rope-chain of Indian manufacture ;and on submit- ting it to the action of nitro-hydrochloric acid for this purpose hc found that it did not dissolve ; and although he obtained some gold in solution yet the form and size of the delicate fabric remained unaltered ;it had become however very brittle and rotten and mas of a dingy brown colour.It was submitted to me for examination by the microscope and when subjected to this scrutinizing agent it was at once evident what had taken place and of what the chain had been compoued. It consisted almost entirely of chloride of silver beautifully crystallised on the surface or strands of the rope .and having in the cross section a radiating structure from the interior to the circumference the central core in some fragments exhibiting still a portion of the original alloy from which the gold had not been removed it having most probably been protected from the action of the acid by the comparatively thick coating of chloride of silver which had bsen formed arouiid it.

ISSN:1743-6893    

DOI:10.1039/QJ8611300031

出版商:RSC    

年代:1861

数据来源: RSC

摘要:

By FREDERICK GUTHRIE'. 11. THEterms isotype and idiotype isotypic and idiotypic may be advantageously adopted to denote bodies which belong to similar types or to the same one and the relations kihich such bodies bear to one another. The application of' these expressions which we almost self-explicatory is best seen in examples. A body is idiotypic with all its replacement derivatives; the latter are of course idiotypic with one another ;the whole are idiotypes Bodies belonging to the same chemical series axe isotypic with one asother or are isotypes. Hence (1.) The idiotypes of the same body are idiotypes of one another. (2.) The isotypes bf the same body are isotypes of one another (3.) The idiotypes of the same body are isotypes of the idiotypes of an isotypic body.(4.) The isotypes of the same body are isotypes of the idiotypes of an idiotypic or isotypic body. In a paper read before the Chemical Society (March 3rd 1859,) I described the formation and some of the properties of the bodies C,H,Cl,S, Clo€IloC12S2 CloHloC1S2 and of some derivatives obtained from them. I purpose now resuming the consideration of this interesting class of bodies obtained by the action of the two chlorides of sulphur upon the olefines and rendering their history somewhat more complete before discussing the behaviour of the other compound halogens towards the same hydrocarbons. In the paper referred to it was asserted that bisulphide of chlorine is without action upon ethylene at temperatures between 0" and 100"C.The hope mas however expressed that the two might combine directly as is the case with amylene if they were subjected to increased pressure. I have since found that even at ordinary pressures an increased temperature is suEcient to deter- mine chemical recomposition ; and from analogies afterwards to be pointed out I conclude that the most probable interpretation of D2 GTJTHRTE ON SOME DERIVATIVES such recomposition is the direct union of the two reagents ethylene and bisulphide of chlorine and the simultaneous decomposition of the product formed. Action of bisukhide of chlorine upon ethylene.-Three or four ounces of bisulphide of chlorine are brought into a retort of two or three pounds capacity. The retort is connected with an inverted condense;.and through a tube passing through the tubulus into the bisulphide a rapid current of pure dry ethyleneis allowed to pass. On heating the bisulphide to ebullition the two substances are brought together in a gaseous state at a tempera-ture of about 139"C.; a condition which appears greatly to pro- mote their reaction. After about 200 litres of ethylene have passed through the liquid which has deepened in colour is trans- ferred to a smaller retort and heated till the boiling point rises to 18OoC. During this distillation as well as during the passage of the ethylene a disengagement of hydrochloric acid takes place. On allowing the residue in the retort to cool a considerable quantity of sulphur separates out. The distillate which contains only a small quantity of substance undecomposible by water may be employed in subsequent operations.In order to free the organic compound in the unvolatilized residue from still adhering bisulphide of chlorine it is after separation from the sulphur digested for many hours with water at 80'. After fresh portions of water no longer become acid the residue which is pasty and opaque is allowed to stand for two or three days in contact with dilute caustic soda. After drying it is digested with ether and the same process of purification followed which has been fre- quently described in my former paper. In burning this substance with oxide of copper it was weighed in an open boat and chlorate of potash was employed. This same method was used with the non-volatile bodies afterwards to be described.In the determination of the sulphur of this and other bodies I have employed carbonate of zinc in conjunction with chlorate of potash instead of the carbonates of soda or magnesia; the first of these attaclrs the glass and the subsequent separa- tion of silicic acid renders the filtration troublesome ; the second is so light as to be prone to projection from the tube; and both are difficult to procure free from sulphuric acid. The carbonate of zinc prepared from the chloride or the oxide of zinc prepared by the combustion of zinc may I think in all cases advantageously FROM THE OLEPINES. replace the before-mentioned carbonates for sulphur determinations. The zinc may also be used in union with oxide of mercury in Russell's method.In all cases however the combustion tube should be about 20 inches long and the anterior eight inches should be kept cold. I. 0.4637 grm. gave 0,3199grm. carbonic acid and 0.0980grm. water. 11. 0.2286 grm. gave 0.0443grrn. water. 111. 0.3960 grm. gave 0.2747 grm carbonic acid and 0.0735 grm. water. IV. 0.2564 grm. gave 0.4559grm. sulphate of baryta. V. 0.12876 grm. gave 0.6178 grm. chloride of silver. Calculated. Found. I. 11. 111. IV. v. Hean. C . . 18.45 18'81 , 18.92 , 72 18-86 H3. . 2-31 2.33 2.12 2.06 , ,2 2.17 Ss . C12. . 24.61 54.62 ,,,) ?t 2 )) 9 24.35 , a> 53.14 24.35 53-14 -__. 99'99 98-52 The substance analysed has accordingly the composition C4H3S2C12 having been formed according to the equation- C4H + 3s2cl = C4H,S2C1 + HC1 + 4s which also explains the liberation of hydrochloric acid and the separation of free sulphur described in the preparation of the body.Probably the most appropriate name for this body would be the bisu@hochloride of chlorethylene its formula being inasmuch as in all likelihood one atom of hydrogen has been replaced by one of chlorine and the so-formed chlorethylene has combined with the bisulphide of chlorine; OF the bisulphide of chlorine has combined with the ethylene to C,H,S,Cl and this body has decomposed two more atoms of bisulphide of chlorine forming hydrochloric acid and bisulphochloride of chlorethylene C,H,S,Cl + 2S2C1 = C {%)-S2C1 f-4s + HCl GUTHRIE ON sonm DERIVATIVES It is clear however that it may be viewed also; either as the bichlorosulphide of vinyl which mould hoPrever be without analogues or as the bisulphide of bichloreth pl Bisulphochloride of chlorethylene is a transparent liquid of light yellow colour.Its taste is sweet and pungent. Its smell when fresh is agreeable being between those of peppermint and of oil of lemons. Three or four drops when swallowed prwluce head- ache. It is soluble in ether and alcohol insoluble in water ; it does not 1-olatilize without decomposition. At 11"C. its specific gravity is 1.599. It is worthy of note that the bichlorosulphide of ethylene C,H,S,Cl obtained by the direct union of chloride of sulphur withi ethylene and described in the former paper differs from the body just described only in having one more atom of hydrogen a differ- ence which might not appear on analysis.The specific gravity of the latter body however is only 1408 its smell is quite distinct and it is much less soluble in ether. The determination of the composition of bisulphochloride of chlorethylene suggested three questions :-(1.) Is its forination preceded by that of the bisulphochloride of ethylene C4H4S2Cl,which undergoes decomposition on heating in presence of two additional molecules of S,C1? (2.) May it be regarded as a sul)stitution-l?roduct of bisnl-phide of ethyl being in fact the bisulphide of bichlorethyl (3.) Does it admit of further exchange of hydrogen for chlorine whether such chlorine replacement-products be identical or not with the hitherto hypothetical chlorine substitution-products of bisuphide of ethyl.*? * Ann.Ch. Phys. [3] xviii. Cahours mentions that chlorine acts upon the bisulphide of ethyl ; but the products do riot appear to have been examincd. FROM THE OLEFINES. The question (1)may be answered approximately by submitting the bisulphochloride of amylene C,,H,,S2Cl described in the former paper to the action of two additional molecules of bisulphidc of chlorine at a high temperature. Question (2) must be answered by submitting bisulphide of ethyl to chlorine. To answer question (3) bisulphochloride of chlorethylene must be acted on by chlorine. On passing dry chlorine into bisulphochloride of chlorethylene a rapid disengagement of hydrochloric acid results accompanied by a liberation of heat which undcr favourable circumstances may raise the temperature of the liquid from 12°C.to 85"C.; at the same time the liquid loses almost all its colour. In the following experiments the reaction mas carried on in the dark Through eight or ten grammes of hisulphochloride of chlor-ethylene dry chlorine was passed until the heat at first developed had abated and the ordinary temperature was re-established. The tube containing the product was then heated in a water-bath to 100"C. and a rapid current of dry chlorine was passed through for two hours. The product was freed from dissolved hydrochloric acid and chlorine by being again heated to 100' C.and subjected to a rapid current of dry carbonic acid for two hours. Even after all the hydrochloric acid was expelled the carbonic acid in passing through the liquid at 100"C. continued to carry off a vapour which both fumed with ammonia and reddened litmus paper. This is due to the vapours of chloride of sulphur and oxychloride of sulphur as we shall presently see. The cold gas-exit-tube became coated with a layer of yellowish transparent ci ystals too small in quantity for examination and consisting probably of oxychloride of sulphur whose formation was due to a trace of moisture After the carbonic acid had passed through duriiig the time mentioned a drop of the liquid did not give up any hydrochloric acid to water It was however digested with warm water dissolved in ether then dried and purified as before.On analysis this body showed the following composition :-grm. grm. grm. I. 0.3737 gave 0.2182 carbonic acid and Q*Q374 water. If. 0.5184 ) 0.4116 sulphate of baryta. 111. 0.4453 , 1.2957 chloride of silver. 40 GUTFIRIE ON SOME DERIVATIVES Calenlated. Found. I. 11. 111. C . . 16*16 15.94 ?Y > H . 1.35 1-11 ?I , S Cl . . . . 10.76 71.73 J) 1 10.88 )7 ,,71.98 - I__.- 9991 100*00 The action of chlorine therefore under these circumstances upon the bisulphochloride of chlorethylen is to replace one atom of hydrogen by chlorine and to eliminate half the sulphur ; thus giving rise to a body whicli may be called the chlorosu&hide of bichlorethy lene.The reaction takes place according to the equation C4H3C12S2+ 3C1 = C,H,Cl,S + HC1 + 3C1 The chlorosulphide of bichlorethylene is a yellowish almost colourless transparent liquid of pungent suffocating and most persistent smell. It mixes with ether and alcohol but is insoluble in water. Although not volatile when heated alone it may be volatilized almost without residue in a current of dry carbonic acid. Its specific gravity is 1.225 at 13*5"C. In order to compare the products of the action of chlorine upon bisulphide of ethyl with those of its action upon the bisulpho- chloride of chlorethylene ten or twelve grammes of the bisulphide of ethyl were exposed to the action of chlorine in the same appa- ratus and as nearly as possible under the same physical conditions as obtained during the action of chlorine upon the bisulphochloride of chloret hylene.On passing a rapid current of dry chlorine into the above quan-tity of bisulphide of ethyl the temperature was raised from 14" to 78' CJabundance of hydrochloric acid being evolved. The first bubbles of chlorine passed through the liquid became opales- cent owing to the separation of sulphur. As however the temperature rose this opalescence speedily disappeared. At one stage the liquid became much darker in colour than the sulphide FROM TEE OLEFINES. of ethyl ; subsequently it regained its light straw-colour ;when this happened the evolution of heat ceased. The liquid product so formed was thereon heated to 100"C.in a water-bath and the current of chlorine continued for two hours; it was then freed from hydrochloric acid and chlorine by a stream of carbonic acid as described in the preparation of the chlorosulphide of bichlor- ethylene. A product was thus obtained having the same colour and yre- cisely the same exceedingly characteristic smell as the chloro- sulphide of bichlorethylene formed as already described by the action of chlorine upon the bisulphochloride of chlorethylene. Its specific gravity was found to be 1.219 at 13.5"C. which is identical with that of the chlorosulphide of bichlorethylene,* Analysis also showed the two to contain the elements carbon hydrogen sulphur and chlorine in the same proportions as they exist in the chloro- sulphide of bich lore t h ylene.I. 0.3623grm. gave 0,2177 grm. carbonic acid and 0.0329grm. water. 11. 0.4073 grm. gave 0.4113 grm. sulphate of baryta. 111. 0.2762 grm. gave 0.7702 grm. chloride of silver. Calculated. Found. I. 11. 111. c4 . 16-16 . . 16.38 1 3 H . 1.35 . . 1-00 7 >¶ s. . 10.76 . ' ,I 11.10 >J >> 69.00 Cl . . 71.73 . -,J 100*00 97-43 This liquid has therefore the formula :-having been formed according to the equation :-C4H5S2+ 7C1 = C4 {%) S + SC1. + 3HC1 and being in accordance with its derivation the suZphide of ter-chlorethy l. * For exact cornparigon the specific gravities of the tao substances were taken in the same vessel and nearly at the mme time GCTTIIRIE ON SOME DERIVATIVES I can detect no difference whatever between the substance just described and that whose analysis was given on page 40 and named the chlorosulphide of bichlorethylene.The empirical formulae of the two are identical C,H,Cl,S ; but if we insist upon evidencing the different sources of the two bodies in their formulze and nariles me must write the oiie :-Chlorosulphide of bichlorethylene SCl the other C (:$-Sulphide of terchlorethyl . c4 -@I s* That these two bodies are identical I believe no one who has had them in his hands will doubt. I must reserve the confirma-tory evidence resulting from the apparent identity of some oxygen derivatives obtained in the same manner from both for another occasion. But from the above facts alone we are perhaps justified in giving an affirmative answer to the question (2) above proposed ; that is we may look upon bisulphochloride of chlorethylene in its behaviour towards chlorine as a chlorine-substitution-product of bisulphide of ethyl.That we do not obtaiii the bisulphochlo- ride of chlorethylene by acting upon bisulphide of ethyl with chlorine is accounted for by the fact already proved that the bisulphochloride of chlorethylene is itself attacked by chlorine. It is highly probable however that the darkening of the liquid mentioned above at one stage of the action of chloriiie upon the bisulphide of ethyl is owing to the formation of the bisulpho- chloride of ehlorethylene which subsequently undergoes further hydlrogen-replacement and elimination of sulphur being convcrted into the chlorosulphide of bichloret hylene.I did not however seek to intercept the process at this point because no criterion could be formed of the intcgral nature of the action and because even if a body of the anticipated composition had been formed it might still have been a mixture of t?le higher substitution-product with the original substance. The identity of the chlorine-substitution-products of C4c,] S,C1 I1 and C,H,S is further of considerable interest inasmuch as it shows that towards chlorine the two are essentially idiotypic and that consequently while we have seen in the case of amylene that a body C,H,S,Cl acts towards oxides and hydrated oxides as the FROM TI-TE OLEFIKES.chloride of a sulphur-radicle; towards chlorine such a body acts as the subhide of a chlorine-radicle. This line of evidence will be more complete after studying the action of chlorine upon the bisulphochloride of amylene previously described If a rapid current of dry chlorine be passed through bisulpho- chloride of amylene C,,H 1oS2Cl hydrochloric acid is evolved. In order to compare this reaction with the action of chlorine upon bisulphide of ethyl and bisulphcchloride of chlorethylene ten or twelve grammes of the bisulphochloride of amylene mere brought into the same apparatus arid subjected to the action of chlorine under tlie same circumstances as attended the action of that ele-ment upon the bodies mentioned. The action was attendcd by an evolution of heat which raised the liquid from 12"to 70" C.The colour changed from a light straw-yellow to a garnet-red at this point I suppose the liquid to consist principally of an intermediate snbstitution-product C * {:f 1S,Cl) arid then became almost' of its original paleness. At this point no more heat m-as evolved. The product being then heated ii? a water-bath the stream of chlorine was continued for two hours. After standing in a stoppered bottle for twelve hours it still smelt strongly of chlorine. The excess of chlorine and the hydrochloriG acid formed mere finally expelled by a stream of dry carbonic acid at 100" C. and the product was purified as before. G1X.I. Grm. Grm I. 0.4853 gave 0.4334carbonic acid and 0.1572water. 11.0,3299 , 0.3228 , , 0.1137 , '111. 0.4241 , 0.3850 , , 0.1368 , IV. 0*5011 , 1.2995 chloride of silver. v. 0.3940 ., 0.2274 sdphate of baryta. VI. 0.6996 , 0.4031 , 9 VII 0.4942 , 0.2810 , 1 GUTHRlE ON SOXE DERIVATIVES The possible substance whose composition approaches most newly to this is the chlorosu@hide of terchloramylene or according to what has been shown concerning the ethylene compounds the sulphide of puudrochloramyt? for these two bodies to whose identity analogy points require C, . . 26.66 H .. 3.11 Cl .. 63.11 S .. 7.11 99.99 The sulphide of quadrochlorarnyl or chlorosulphide of terchlor- amylene closely resembles in smell taste and physical properties the ethylene substitution-products already discussed.It is a trans-parent non-volatile light yellow liquid of specific gravity 1.406 at 16O C It is insoluble in water miscible with ether and soluble in hot alcohol. Fourteen grammes of amylene were gradually mixed at the closed end of a combustion-tube four feet long with more than three equivalents of bisulphide of chlorioe. The mixture having been kept boiling for eight hours (during which hydrochloric acid was copiously evolved) was transferred to a retort and heated till its temperature rose to 190°-C After cooling and decanting from the small quantity of separated sulphur the product was washed with ‘aqueous caustic soda etc. 0.4148 grm. gave 0-4411 grm. of carbonic acid and 0.1680 grm. water. 0.7006 grm. gave 0.6362 grm. of chloride of silver.These numbers show 28-76per cent. of carbon 4.50 per cent. of hydrogen and 22.46 per cent. of chlorine; a result which points to no simple formula. The product was probably a mixture. It is very worthy of notice that the body resulting from the action of chlorine upon the bisulphochloride of amylene is not an FROM THE OLEFINES. analogue of that derived by chlorine from the bisulphochloride of chlorethylene (i.e. from the bisulphide of bichlorethyl) and from the bisulphide of ethyl. Comparing their general formulze we have i2-41 for the first C, S and for the second Czm{c";;.-3] s. But; this difference which might seem to indicate an anomalous behaviour in the two cases really results from the symmetry of the two recompositions effected by chlorine ; a symmetry which ex-tends moreover to the chlorine-substit ution-products of the mono- sulphide of ethyl studied by Regnault." Putting the reations together :-is into by the ex-4 H for 3 €I for 3 C1 H for C1 3 H for 3 C1 change of 14C1 and SC1 for C1 and SCl for Cl C1 for SC1 Thus in all cases but the third a fourfold exchange is effected; and that here merely a twofold exchange occurs may be attri- buted to the body reckoned from the bisulphide of ethyl having already suffered a two-fold replacement.It has been already shown in the first paper that SC1 is monomolecular and may be replaced by a single atom of chlorine. Particularly remarkable is the analogy between (2) and (4) proving as it does that these two substances are towards ciitorine isotypic.The above bodies furnish examples of the proneness which chlorine has to replace even numbers of molecules. ?n order to throw some more light upon the constitution of bisulphochloride of amylene I have subjected that body to the action of nitric acid; but before describing the products obtained by this reaction it will be well to consider briefly the action of nitric acid upon amylene itself. The temperature at which nitric acid and amylene act upon one another is so far above the boiling point of the latter body that great loss of amylene results if the two are heated together * Ann. Ch.Phys. [3] Ixxi 387. GUTHRIE ON SOXE DERIVATIVES even in capacious vessels until the reaction commences.If five or six grammes of amylene be shaken in a bolt-head with four OT five times the volume of fuming nitric acid and heat be applied until the acid boils a sudden evolution of nitrogen-oxides results thc neck of the bolt-head becomes coated iiith a thin layer of fatty white crystals and green oily drops heavier than nitric acid appear in that liquid. For the above-mentioned reason however this method of tracing the reaction was abandoned and the following one employed. Air dried by passing over chloride of calcium in the tube a is made to bubble through amylene contained in the bulbs 6 and being thus charged with the vapour of amylene it is led through fuming nitric acid in the retort c which has previously been heated to boiling and which is kept so during the passage of the The retort is connected with a condenser.If the volume of gas. the nitric acid be about seven times as great na that of the amylene and if the current of air and the heat of the retort be so regulated that the amylene and nitric acid are volatilized nearly together almost the whole of the non-gaseous products consists of the white fatty crystalline substance before mentioned which coats the surface of the receiver ; the greater quantity however is deposited in the tube of the condenser and may thence be washed into. the receiver. Water is added to the latter and it is vigorously shaken until the product cakes together. Although heavier than water it generally floats upon its surface owing to the presence of small gas-bubbles.After washing with cold water on a funnel and drying between blotting paper it is strongly pressed to remove traces of the liquid product mentioned before and then recrystallized from boiliug anhydrous ether. If the ethereal solution be allowed to cool without evaporation the substance crystallizes out in long rectangular prisms. If the FROM TIIE OLEFINES. crystallization be helped by evaporation it separates as flat rectan- gular tables. Under the microscop;= no other than right anglen could be observed in either case. Burnt with oxide of copper metallic copper being employed ia the anterior of the tube I. 0.3680 grm. gave 0.5019 grm. carbonic acid and 0.2056grm. water. 11. 0.1330 grm. gave 19.1 cc of nitrogen at OOC.and 760 mm Calculated. I. 11. c,o ' . 37-09 37-20 , HI0 . 6-18 6.24 1 N2 . 17.28 > 18'0h 0 This substance may therefore be called binitroxamylene its formula being- A portion of the nitric acid is deoxidized to NO,; this com- bines with the oxygen of the excess of air to form NO,; and the latter molecule urzites directly with a fresh portion of arnylene. This same substance which can be obtained only in small quantities by the above process may be prepared in any desired quantity by the direct union NO with arnylcne. The latter method of preparing this body together with some of its pro- perties will appear in the next communication.

ISSN:1743-6893    

DOI:10.1039/QJ8611300035

出版商:RSC    

年代:1861

数据来源: RSC

摘要:

48 VIL-On the Grystallised Hydrates of Baryta and Strontia BY CHARLESL BLOXAM. CONSIDERABLE difference of opinion appears to exist among chemi- cal authors with respect to the composition of the crystallised hydrates of baryta and strontia some representing them as contain- ing 8 eqs. others 9 eqs. and others even 10 eqs. of water whilst in some cases these hydrates so closely analogous in their chemical relations are represented as crystallising with different amounts of water. Having had occasion to satisfy myself with respect to their true composition I beg to submit the results of my analysis to the Society. The crystallised hydrate of baryta was prepared according to the method recommended by Mohr by adding powdered nitrate of baryta to a boiling solution of an equivalent quantity of hydrate of soda.The crystals which separated from the cooled liquid were purified by two crystallisations. On examining the solution from which the first crop of crystals had been deposited it was found to contain a considerable quantity of undecomposed nitrate of baryta together with some hydrate of soda showing that the decomposition of the nitrate by a single equivalent of soda was far from complete. In a second preparation 1.4 eqs. of hydrate of soda were employed but in this case also a considerable quantity of the nitrate of baryta was left undecorn- posed though less than in the first experiment. The hydrate of baryta exhibited in a remarkable degree the tendency to remain without mystallising in a super-saturated solution until it was either briskly stirred or placed in contact with a crystal of the hydrate.On attempting to dry the crystals in vacuo over oil of vitriol they soon became opaque which was at first attributed to the for-mation of a thin film of carbonate but was afterwards found to arise from loss of water; indeed the crystals were found to effloresce even in air of ordinary humidity which may help to explain the discrepancy in the results which they have afforded to different analysts. CRFSTALLISED RPDRATES OF BARYTA AXD STRONTIA 49 In order to determine the amount of water lost in vacuo over oil of vitriol separate samples of the crystals obtained in two dis- tinct operations mere exposed in a receiver of air over quick lime and weighed at short intervals until the loss of weight in a given period suddenly diminished and the first sign of efflorescence began to show itself upon the edges of the crystals.Two determinations of adhering water made in this way gave respectively 1.39 and 1-24per cent. The dry crystals were then exposed in vacuo over oil of vitriol until they ceased to lose weight. The effloresced hydrate thus obtained was heated to dull redness in a closely covered silver crucible and weighed at intervals of four or five minutes until it began to increase in weight slightly, from absorption of carbonic acid. The baryta was also precipitated and determined as sulphate both in the original dry crystals and in the effloresced hydrate.The subjoined table contains the results of these experiments calculated for 100 parts of the dry crystallised hydrate. Calculateil (Ba = 685) I I1 111 IV V VI Mean. Ba0,HO + HO + 7Aq. Water lost in V~CUO 3936 39 30 39 69 39.84 39.63 39.56 po.00 , , on ignition 5 93 6 04 6.12 6.03) 45'59 5-71) 45*'i1 Baryta 48'12 48-42 48.26 48-26 48.57 These numbers appear to warrant the conclusion that the formula of the crystallised hydrate of barpta is Ba0,HO + 8Aq. and that of the efloresced hydrate Ba0,HO + Aq the pure hydrate Ba0,HO being obtained by igniting the latter. The effloresced hydrate suffered no more loss of water at 21.2"F even in vacuo. It is worthy of iiotice that this effloresced hydrate evolved much beat when moistened with water.The crystallised hydrate of strontia was also prepared by decom- posing the nitrate of strontia with hydrate of soda at the boiling point; in this case nearly 2 eqs. of the hydrate mere employed for each equivalent of nitrate of strontia and this salt was found to have been completely decomposed. The hydrate of strontia how-ever did not dissolve in the liquid like the hydrate of baryta but separated in the form of a granular precipitate which had the same composition as the crystallisecl hydrate. On pouring off the solution containing the nitrate of soda and boiling this granular precipitate with successive portions of water very large and beau-T'OL. XI'II. E 50 BLOXAM ON CRYSTALLTSED RYDRATES OP BARYTA &c. tiful cry&& were obtained which were purified by recrystallisa- tiOD.The crystals effloresced in the same way as those of hydrate of bavyta. They were analysed in a similar manner the strontia beiag completely precipitated by sulphuric acid and alcohol and the sulphate of strontia subsequently washed with alcohol. The results are seen in the following table. Calculated (Sr = 43%) I 11 111 IV Mean. 47 '77 16040 SiQ,€IO + HO -i-7hq Water lost hvacuo . . . 4779 4775 ;:::)-61-00 , , on ignition . . . 19-61 12 65 12-63 t%mntf . . . . 39.18 39.04 3912 3906 39 00 It appears then as would be expected that the formula of the crystallised hydrate of strontia is Sr0,HO + 8Aq and that of the effloresced hydrate Sr0,HO + Aq but that when this latter is heated to dull redness it loses the whole of its water anhydrous strontia being left.* 'The effloresced hydrate did not lose any more water in the water-oven at 212' F but when raised to this temperature in vacao it lost 12-89 per cent.or exactly one equivalent of water thus becoming converted into the simple hydrate Sr0,I-KO.? Both this and the effloresced hydrate evolved heat when moistened with water. The inferio;. power possessed by strontia to retain these two last equivalents of water is another interesting example of the gracla-tion constantly observed in the properties of baryta and strontia; and I must express my regret that want of leisure precludes me for the present from examining tlic crystallised hydrate of lime which may be expected to occupy a still lower position iyith respect;to its power of retaining water of crystallisatiou. * I fmd that %his circamstance had been already pointed out by Den4am Smith (Phil. Mag. [3] ix 87) although chemical writers have still represented the hydrate ofofBtrontiaas permanent at a red heat. + The effloresced hydrate also lost nearly the whole of its second equivaIent of water when exposed for a very long time over very concentrated oil of vitriol in VllCUO.

ISSN:1743-6893    

DOI:10.1039/QJ8611300048

出版商:RSC    

年代:1861

数据来源: RSC

摘要:

51 VII1.-Miscellaneous Obseruatjons. BY A. W HOFMANN. 11. (Continued from Vol. X ,p. 211.) 4. Action of Nitrous Acid upon Nitrophenylene-c~~~~e. THE experiments of Gottlieb have shown that dinitrophenyl- arnine when boiled with sulphide of ammonium is converted into a remarkable base crystallising in crimson needles generally known as Nitraxophenylamine and for which in accordance with the views I entertain regarding its constitution I now propose the name iVitro~henyZene-diamine. I owe to the kindness of Dr. Vincent Hall a considerable quantity of this substance which is not quite easily procured. In preparing it DP. Hall has in the first place followed the succession of processes recommended by Got tlie b viz. treatment of phenyl-citraconimide (citraconanile) with nitro-sulphuric acid transformation of the nitro-substitute into dinitrophenylamine and the reduction of the latter by sulphide of ammonium.In other experiments Dr. Hall has availed himself with the same advantage of phenyl-succinimide (succinanile) which under the influence of a mixture of nitric and sulphuric acid exhibits a deportment similar to that of the citraconyl-body. Dinitrophenyl-succinimide is readily transformed into dinitro-phenylamine which ultimately yields the crimson-coloured com- pound. To the accurate description which Gottlieb has given of the preparation and the properties of this substance I have scarcely to add a single word. The following remarks refer to an experi-ment made with the view of obtaining some insight into the molecular construction of the body.If bearing in mind the hUIzlerOUs analogies of the radicals ethyl and phenyl we assume that the latter by the loss of hydrogen may be converted into a diatomic molecule pheuylene C6H4,* comespondkg to ethgldne the existence of a group of phenylene-bases corresponding to the ethylene-bases camot be doubted. * H=I C=12,O=lG 8=32,etc. E2 HOFMANN ON ACTfON OF NITROUS ACID (C2H,)”] Ethylamine c2:5] N Ethylene-diamine €1 N H H2 Phenylamine ‘f?)N Phenylene-diarnine(C6g’’1N2. H H2 The compound known as semibenzidam or azophenylamine which Zinin obtained by exhausting the action of sdphide of ammonium on dinitrobenzol agrees with the last-named body in composition.Tliose chemists however who have had an opportunity of becoming acquainted with the well-defined properties of ethylene-diamine will not easily be persuaded to consider the uncouth dinitrobenzol -product sometimes appearing in brown flakes sometimes as a yellow resin rapidly turning green in contact with the air as standing to phenylamine in a relation similar to that which obtains between ethylene-diamine and ethylamine. We much more readily admit a connection of this description between phenylamine and Got tlieb’s crimson-coioured base in which the clearly pronounced character of the former is still distinctly visible although of necessity modified by the further substitution which has taken place within the radical. ‘6H51 Phen ylamine H N [“3 ” > ] *,* Nitrophenylen e- di amine H2 H2 Does the latter formula really represent the molecular constitu- tion of the crimson needles? The degree of substitution of this body might have been determined by the frequently adopted pro-cess of ethylation.But even a simpler and shorter method appeared to present itself in the beautiful mode of substituting nitrogen into the place of bydrogen lately discovered by P. Griess. The red crystals undergo indeed with the greatest facility the transformation which he has proved already for a great many derivI?tives of ammonia. (‘6 UPON NITROPHENY LENE-DIAMINE. On passing a current of nitrous acid into a moderately con-centrated solution of the nitrate of the base the liquid becomes gently heated and deposits on cooling a considerable quantity of brilliant white needles the purification of which presents no difficulty; being sparingly soluble in cold readily soluble in boiling water the new compound requires only to be once or twice re-crystallised.Thus purified the new substance forms long prismatic crystals frequently interlaced white as long as they are in the solution but assuming a slightly yellowish tint when dried and especially when exposed to looo; they are readily soluble both in alcohol and in ether. The new body exhibits a distinctly acid reaction; it dissolves on application of a gentle heat in potassa and ammonia without however neutralizing the alkaline character of these bases; it also dissolves in the alkaline carbonates but without expelling their carbonic acid.The new acid fuses at 211O C. and sublimes at a somewhat higher temperature with partial decomposition. The sublimate consists of small prismatic crystals. Analysis gave the following results :-I. 0.3290 grm. acid dried at loo" gave 0*5298 , carbonic acid and 00777 , water. 11. 0-2868grm. acid gave 84 cc. moist nitrogen at 15O and 0.7583Bar. (corr.) These numbers lead to the ratio:- and the origin of the substance being taken into coasiderakkm fA the formula :-CG~4~*02* Theory. Experiment. I. 11. C 72 43.90 43-92 -fi* 4 2.44 2.62 -N 56 34.15 -34.32 LI .-. 0 32 1951 -1_1-1641 100*00 This fornd is confirmed by the analysis of the silver- and of the potassium-compound.HOPlrZAIW ON ACTION OF NITROUS ACID SiZ~er~saZt.This salt is obtained in the form of a white amorphous precipitate on mixing the saturated ammonia-solution of the acid with nitrate of silver. 1%wucuo this salt may be dried without decomposition; at 100' it becomes slightly coloured ; when gently heated on platinum foil it detonates. The silver therefore had to be estimated as chloride. 1 0.4215 grm. silver-salt gave 0*4068 , carbonic acid and 0.0487 , water. 11. cI.2984 , silver-salt gave 0.1574 , chloride of silver. The formula C,fH,Agf N402involves the following values :-Theory. Experiment. C 72 26-57 I. 26.32 11. - H3 3 1.11 1.28 - N4Ag 56 108 20.66 39.85 - L 3967 0 32 ll*81 - I_ I__ 271 100*00 Patssizcm-salt.Obtained in pretty well -formed flattened prisms by saturating a moderately concentrated boiling solution of potassa with the acid; the crystals are difficultly soluble in potassa but exceedingly soluble in pure water and in alcohol ; the recrystdization is therefore attended with very considerable loss. The aqueous solution of the salt yields a crystalline precipitate on addition of potassa. The salt even after four or five recrystal- lizations from alcohol retairis a distinctly alkaline reaction. Its composition was fixed by a potassium determination. 0.2012grm. salt dried at 100° gave 0.0857 , sulphate of potassium. UPON NITBOPEENPLENE-DIAMINE. 55 The formula C CH3K] N,O requires the following values :-Theory Experiment.C 72 35.64 -I J33 3 1*48 K 39 19.31 19.10 N 56 27.72 -0 32 15.85 -___. -202 100.00 With regard to the other salts I have made but fmv observa-tions. The ammonium-salt crystallizes in needles. It has however but little stability losing the whole of the ammonia when re-peatedly recrystallized. The solution of this salt exhibits with metallic oxides the following deportment. Barium and calcium-salts are not precipitated. Salts of copper give a light blue salts of nickel a light green precipitatc. The solution of a ferrous salt produces a deep brown-red precipitate probably with simultaneous decomposition of the acid; the solution of a ferric salt a light fawn-coloured precipitate. The salts of ~~o~ lead zinc manganese and mercury (~e~ and mercuricum) u~ furnish white flaky precipitates.The analysis of the new compound shows that under the influence of nitrous acid on nitrophenylene-diamine one molecule of nitrogen is substituted into the place of three molecules of hydrogen which are eliminated in the form of water C,H,N,O + X-INO = 2 N,O -I-C6[H4N]N,0 Nitrophenylene-New acid. diamine. I do not propose a name for the new compound which can claim but a passing interest as throwing by its formation some light on the constitution of nitrophenylene-diamine. The composition of the new acid and of its salts shows that in the crimson base four hydrogen molecules are still capable of' replacement; in other words that this body still contains four extra-radical molecules of hydrogen.These experiments appear to confirm the view which in the commencement of this note I have taken of the constitution of the body; at all events the mutual relation of the several compounds is satisfactorily illus- trated by the fol.nnulze- New acid If the admissibility of this interpretation be confirmed by further experiments the reaction discovered by Gri e ss furnishes a new and valuable method of recognising the degree of substitu-tion in the derivatives of ammonia. The new acid differs in many respects from the substances similarly produced from other nitrogenous compounds. As c2 class these substances are remarkable for the facility with which they are changed under the influence of acids and more especially of bases.The new acid exhibits remarkable stability ; it may be boiled either with potassa or with hydrochloric acid without undergoing the slightest change. Even a current of nitrous acid passed into either the aqueous or alcoholic solu- tion is without the slightest effect. The latter experiment was repeatedly performed; for if the action of nitrous acid in a second phase of the process had assumed the forin so frequently observed by Piria and others it might have led to the formation of the diatomic nitroph~nylene-alcohol according to the equation It deserves to be noticed tliat nitrophenylene-diamine although derived from two molecules of ammonia is nevertheless a decidedly mono-acid base. pot tlieb’s analyses of the chloride nitrate and sulphatc left scarcely a doubt on this point.How-ever as some of the natural bases quinine for instance are UPON NITliOl’HEEX’Y LICK E-1,I A 311h’li capable of combining either with one or with .two molecules of acid I thought it of sufficient interest to confirm Gottlieb’s observations by some additional experiments. The crystals depo- sited on cooling from a solution of nitrophenylene-diamine in concentrated hydrochloric acid werc washed with the same liquid and dried in vacuo over lime. 0.3975 grm. substaiice gave 0.3005 , chloride of silver = 18.70 p. c. of chlorine. The formula requires 18.73 p. c. of chtorinc. The dilute solution of the previous salt is not precipitated by dichloride of platinum; nor could the double salt of the two chlorides be obtained by evaporating thc mixture of the two solutions which just as Got t 1ie b observed was readily decom- posed with separation of inetallic platinum.I had hornever no difficulty in preparing a platinum-salt crystallizing in splendid long brown-red prisms by adding the platinum solution to the concentrated solution of the hydrochlorat e. Q*4225grm. of the platinum-salt dried in uucuo left on ignition 0.115 grni. = 27.22 p. c. of platinum. The theoretical percentage of the formula is 27.48 p. c. of platinum. These experiments prove that even uiider thc most favourable circumstances nitrophenylene-diamine combines with only 1eq. of acid while the ethylene-deriyatives are decidedly diacid. The diminution of saturating power in uiti~~vhenglene-diamin~ at the first glance seems somewhat anomalous ; but the anomaly disap- pears if the coustitution of the body be more accuratcly examined.It cannot be doubted that the diminutioii of the saturating power is clue to the substitution which has talten place within the radical HOP1MAXN ON ACTIOX OF NITROUB ACID of the diamine. J pointed out some time ago,* that the basic character of phenylamine itseif is considerably modified by suc- cessive changes induced in the pheny l-radical by substitution Chlorphenylamine though less basic than the normal compound still forms well-defined salts with the acids; the salts of dichlor-phenylamine on the other hand are so feeble that under the influence of boiling water they are split into their constituents; and in trichlorphenylamine the basic character has entirely dis- appeared.Again on examining the nitro-substitutes of pheny-lamine we find that even nitrophcnylamine is an exceedingly weak base whilst dinitrophenylamine is perfectly indifferent. What wonder then that a molecular system to which in the normal condition we attribute a diacid character should by the insertion of special radicals be reduced to monoacidity? The normal phenylene-diamine which remains to be discovered will doubt- less be found to be diacid like the diamines derived from ethylene. Even now the group of diacid diamines is represented in the naphtyl-series. Napht ylamine "''g7] N monoacid. H 10 6 Naphtylene-diamine N, diacid.'' &)] 1% The body which I designate by the term naphtylene-diamine is the base which Zinin obtained by the final action of sulphide of ammonium upon dinitronaphtalin This substance originally designated as seminaphtalidam and subsequently described as naphtalidine corn bines according to Zinin's experiments with two equivalents of hydrochloric acid.? I must add a remark suggested by the perusal of ail interest- ing paper lately published by Kolbe.1 In this paper Kolbe refers to an outline of the history of ammonia and its derivatives which in the form of an evening lecture I gave to the members of this Society and which was subsequently printed in this journal.$ Kolbe regards many of the ammonia-cornpounds from a different point of view and expresses them by molecular * Mem.of Chem. SOC.,ii 298. C Ann. Ch. Pharm. lxxxv 328. $ Ueber den naturlichen Zusammenhang der organischen rnit den unorgwniscben Verbindungen.-Ann. Ch. Pharm. cxiii 293, $ Cbem. SOC.Qu J. xi 65% UPON NITROPHENYLENE-D;iAMIME. 50 formulae different from those which I have adopted. It is not my intention to refer in detail to the several qnestions which he discusses mQre cspecially since many of the theoretical views in which we differ were brought forward by others and mere simply introduced into the sketch with the view of rendering it as complete as possible; yet I must riot allow this opportunity to pass without a word or two in elucidation of a question on which we differ more in appearance than in reality.In classifying the basic ammonia-derivatives I proposed to designate the substances formed by the coalescence of more than one molecule of ammonia in accordance with the nomenclature adopted for the neutral derivatives and to distinguish as mona- mines diarnines and triamines the bases derived from one two or three molecules of ammonia. In a classification of this kind the circumstance could not be left unnoticed that inany of the diamines and triamines combine with one equivalent of acid only instead of saturating as might have been expected from their construction two or three equivalents. I was thus natu- rally led to subdivide again and to distinguish for instance monoacid and diacid diamines and I added It is obvious that the question whether a diamine is capable of uniting with one or two equivalents of acid must be intimately connected with the molecular construction of the basic system As yet the nature of this connection remains unknown.” In the paper quoted Kolbe remarks lCThere appears no reason why among the bodies derived from two molecules of ammonia there should be side by side with the diatomic sub- stances others yielding monoatomic ammonium-compounds.I cannot therefore consent to regard the ureas melaniline and other bases containing two atoms of nitrogen as true diamines.” It is scarcely neceswp to state that I entirely agree with my friend if he views as true diamines those bases which unite with two equivalents of acid; for it is proved experimentally that the ureas and melaniline combine with oiie equivalent of acid only All depends upon the definition of the word diamine.X had de- signated by this name basic compounds dmived from two molecules of ammonia without reference to the degree of saturating power ; and even now it appears to me somemhltt arbitrary to limit this term to those substances which unite with two equivalents of acid especially since there are diatomic bases which are capable ctf combining either with one or with two equivalents of acid. NOFXA" ON T11X ACTION OF BISULPEIIDE OF 5 Action of Bisulphide of Carbon upon Amylamine. In a note on the alleged transformation of thialdine into leucinc communicated some time ago* to the Chemical Society I alluded to a crystalline substance observed by "Vagner when he sub- mitted amylamine to the action of bisulphide of carbon.Wagner had not analysed this substance but considering its mode of formation he had suggested that it might posaibly be thialdine A simple comparison of the properties of thialdine with those of the substancc produced by the action of bisulphide of carbon upon amylamine had enabled me at once to recognise the differ- ence between the two bodies; and satisfied with the result I had not at the time examined more minutely iuto the nature of the latter substance. The new interest conferred by recent researches upon leuciiie and its homologues has recalled my attention to the sulphuretted derivative of amylamine. This body may be readily procured by mixing anhydrous amyl- amine with a solution of dry bisulphide of carbon in anhydrous ether.The inixture becomes warm and deposits on cooling white shining scales which are insoluble in ether and may there-fore be purified by washing them with this liquid. The new body is likewise insoluble in water but readily dissolves in alcohol; when dry it may be exposed for a while to a temperature of 100"C. without fusing; after some time however the substance begins to be liquefied and to undergo complete decomposition sulphuretted hydrogen being evolved. The same change occurs although more slowly at the common temperature; a mixture of free sulphur with a new crystalline body extremely fusible inso- luble in water but soluble both in alcohol and ether remaining behind.I. 0.274grm. of the amylsmine-body burnt with a mixture of oxide of copper and chromate of lead gave 0.535 grm. of carbonic acid and 0.2535 grm. of water. * d'hem. Soc. Qu. J. H 103. H-1 C=l% O=16 8=32. CARBON UPOX AMPLAMIPI’E. GI 11. 0.429 grm. of substance dissolved in alcohol and boiled for some time with nitrate of silver gave 0.837 grm. of sulphide of silver. These numbcrs lead to the formula Theory. Experiment. I. 11. C, 132 5.2.8 53.25 -10.28 -I-I!26 26 10.4 I N2 28 11.2 -s!2 -64 25.6 -25.17 -250 100.0 The new substance then is formed simply by the union of two mole- cules of amylamine with one molecule of bisulphide of carbon. 2C,H13Ni-CS = C11H26N2S2 Amylamine. New cornpound.A glance at this formula suffices to characterize this substance as amyl-sulphocarbamate of amylammonium This view is readily confirmed by experiment. Addition of hydrochloric acid to the crystalline compound immediately sepa- rates an oily liquid which gradually solidifies and the acid soln- tion then contains amylamine which may be liberated by potassa. The oily substance is obviously amyl-sulphocarbamic acid. This body is readily soluble in ether by which it may be separated from the chloride of amylammonium; it dissolves in ammonia and in potassa ; mixed with amylaiaine it reproduces the origind crystal- line compound. Experiments with ethylamine have furnished perfectly analogous results. I have been satisfied to establish qualitatively the analogy of the reactions.It is of some interest to compare the deportment of amylamine under the influence of bisulphide of carbon with that of phenyl-arnine in the same conditions If them two bodies gave rise to HOFXANN ON similar changes we should expect in the case of phenylamine the formation of phenyl-sulphocarbarnate of phenylammonium. But experiment proves that phenylamine produces diphenyl- sulpliocar- honyl-diamide (sulphocarbanilide) sulphuretted hydrogen being evolved :-2C,H,N + CS = C,,H,,N,S + H,S. Phenylamine Diphenyl-sulpho-cahon9-diamide Nevertheless it is extremely probable that further experiments will establish the perfect analogy in the deportment of amylamine and phenylamine with bisulphide of carbon.Diphenyl-sulpho-carbonyl-diamide is probably the product of decomposition of a very unstable phenyl-sulpliocarbamate of phenylammonium-C,,H,,N2S = H,S + C1333,2NgS Phenyl sulphoearba- mate of phenylam-monium. Diphengl-sulpho-carbon yl-diamide. while a more minute examination of the crystalline substance obtained by the action of heat upon amyl-sulphocarbamate of amylammonium cannot fail to characterize it as diamyl-sulphocar-bonyl-diamide. C,lH,fP,S2 = H2f3 4-________ C,lH24N,S Amyl-aulphocarba-Dismyl-sulphocar-mate of amylani-bonyl-diamide, monium. The apparent dissimilarity of tlie two reactions would thus be reduced to the unequal stability of the sulphocarbamic acids of the amyl-and phenyl-series. 6. On the use of Pentachloride of Alztimo~yin the Preparation of Chla.l.ine-coi~~o~~~s Under a cloudless sky nobody wsuld think of preparing the tetrachloride of carbon by any other process than by acting with chlorine upon chloroform.Exposed to direct sunlight chlom- form when [distilled in an atmosphere of chlorine is rapidly csuverted into htmhloride of carbon. A London November sky iS however rather unfavourable to this process anif ps’ihert.requip- PENTACHLORIDE OF ANTIMONY. ing lately for some experiments a small quantity of the tetra- chloride I was compelled to have recourse to another method. A well-known process for which we are indebted to Prof. Kolbe consists in submitting the bisulphide of carbon to the action of chlorine at a red heat when chloride of sulphur and chloride of carbon are formed.I have repeatedly availed myself of this procem which when a large quantity of chloride of carbon is to be prepared leaves nothing to be desired. When however a small amount is rapidly required the apparatus involved in this process becomes rather inconveniently troublesome. I have therefore endeavoured to substitute chlorine in a state of combination for the free chlorine. Pentachloride of phos-phorus as is well known exerts so little action upon bisulphide of carbon that it has been found convenient to prepare the penta- chloride of phosphorus by saturating a solution of phosphorus in bigdphide of carbon with chlorine gas. There is likewise no reactiun between pentachloride of phosphorus and bisulphide of carbon at 100"under pressure ;it is only at a higher temperature that an action takes place.A. very different result is obtained when the latter compound is submitted to the action of penta-ehloride of antimony the chlorinating properties of which wewe first noticed by Wijhler. On adding pentachloride of antimony to bisulphide of carbon a tmnsparent mixture is obtained which exhibits after a few minutes a powerful reaction becoming very hot and assumiug pd dark reddish-brown colour ; the mixture deposits on cooling a oopious crystallization of terchloride of antimony interspersed with well-kmed sulphur-crystals. The liquid poured off from the crystals consists chiefly of tetrachloride of carbon retaining some bisulphide of carbon chloride of sulphur and terchtoride of antilposy 3-CS + 2SbC1 = CC1 + RSbCl + S, I had expected that the reaction mould give rise to the forma- tion of a compound SbC1,S; but I have always found that the terchloride of antimony and the sulphur are separately deposited ; and the same observation was made by Mr.H. McLeod who has frequently carried out this reaction in my laboratory modifying the proportiours and the carditions of the experiment to a consi-derable extent. The small quantity of chloride of sulphur .d.Erich is ahultaneously formed appears to be the prodnet of a secondary reaction a portion of the pentachloride not yet acted upon being reduced by the separated sulphur If the experiment be made with a couple of ounces the two liquids must be mixed in a flask provided with a vertical cooling apparatus ; the reaction is so powerful that a considerable quantity of the material would be lost without this precaution.Whilst studying this process I have allowed the two liquids to act upon each other in various proportions on employing 1 eq of bisulphide of carbon (1 part by weight) and 2 eq. of penta- chloride of antiniony (8 parts by weight) the decomposition is pretty complete; on account of the foriiiation of chloride of sulphur however thc theoretical quantity of chloride of carbon is never reached. The process yields a much more copious result when the pentachloride of antimony is mixed with a considerable excess of bisulphide of carbon and the mixture whilst boiling irm a retort is submitted to the action of a current of chlorine gas In this manner large quantities of bisulphide of carbon may be transformed into the tetrachloride by the intervention of a com-paratively small quantity of pentachloride of antimony.In order to purify the tetrachloride of carbon the product of the reaction is submitted to distillation; the liquid passing over below 1C3O is boiled for some time with a solution of potassap which removes terchloride of antimony and chloiide of sdphm together vith any undecomposed bisulphide of carbon. From the product boiling at a higher temperature a considerable quantity of pure terchloride of antimony may be recovered. The tetrachloride obtained by this process exhibits all the properties of the product obtained by other modes of preparation It boils at 77".The determination of the chlorine gave the following results :-0.195 grm. of substance ignited with lime furnished 0*7W chloride of silver. c-Theory. Experiment. -c 12 7.79 c1* 142 92.21 9256. 154 100*00 Pentachloride of antimony may be used with &antage in many-cases as a carrier of free chlorine. On heatmg a veqr moderate quantity of pentachloride of antimony in a retort cmnected with an inverted cooling apparatus and passing simultsneously currents of dry olefiant gas and chlorine through the boiling liquid a very large amount of Dutch liquid may be obtained in an exceedingly short time. In an atmosphere of pentachloricle of antimony tlie combination of the ethylene and the chlorine goes on with the greatest facility.As soon as the retort is filled with the Dutch liquid the access of the two gases is interrupted and the liquid distilled. The portion boiling below 100' requires only to be once more rectified in order to farnisli perfectly pure bichloridc of ethylene. The reaidaxe in the retort consists of a mixture of terchloride and pentacliloride of a?ztimony which may serve for a new experiment. The preparation of large quantities of pentachtoride of antimony presents no difficulty whaterer since aiitiniony combines readily with chlorine at the common temperature. &4 simple mode of proceeding consists in introducing the antimony coarsely pox- dered into a combustion-tube from 5 to 6 feet long rising at ail angle of 10" or 15' one end of which is fitted into one tubu-lature of a two-iiecked glass globe the othcr neck of the globe communicating with a tube supplying dry chlorine gas.The combination taking place in the tube the product flows baclrn ards into the globe whilst the long layer of itntimony preFents tlic escape of any chlorine. Being engaged in some experiments on the action of chloride of' carbon CC1 on the phosphorus-bases I thought it desirable to study likewise the deportment of these substances under the influence of the corresponding iodide. Bearing in mind tlic facility with which chloroform is conmrted into chloride of carbon I had some hope of procuring the iodide by thc action of dry iodine upon iodoform :-CHI3 + I = HI 3.CI (2) When a mixture of iocloform and iodine in thc equivalent pro-portions of the above equation was exposed in scaled tubes to n temperature of from 140" to 15QQC.,the iodoform was fwimd to bc changed after the lapse of some hoirrs. On opening the tubes ail acid gas was erolrccl; and on distilling the (lark solid rcsidiir with \oi. xIrr. 1' HOFMASN ON water an aromatic body passed over whicIi collected in the receiver in the form of heavy oily drops. Decolorized by potasstl and freed from water by chloride of calcium the oily body boiled at about 18Qc,a considerable portion being decomposed with evolution of liydriodic acid and the distillnte reassuming the red coloration. The liquid was therefore distilled in uacuo; it then passed over colourless and vithout decomposition at a tempera-ture scarcely higher than the hiling point of water.I. 1.222 grm. of substame burnt with chromate of lead gave 0°2077 grm. of carbonic acid and 0.0800 grm of water. 11. 0.705 grm. of substance burnt with lime furnished 1.243 grm. of iodide of silver. These numbers represent the composition of di-iodide of metlip-lene-CH,I only recently discovered by Routlerom,* Theory. Experiment. 1. IT. c 12 4.418 4.63 -%? 2 0.74 0.73 -I 254 94.78 __. 95.27 268 1oo.oc) The compourid analysed mas indeed pure di-iodide of methylenc. At a temperature near the freezing point of water it solidified in large crystalline plates and exhibited in every respect the pro- perties described by Boutlerow.The analysis of the substance received moreover additional confirmation in a variety of substi-tutions in which it was subsequently employecl. The idea naturally suggested itself that the free iodine had i10 share in the formation of the di-iodide of methylene in the process described but that the transformation of the iodoforrn was ex-clusively due to the action of heat. Experiment has verified this anticipation. Iodoforxn when heated by itself in sealed tubes at a temperature of 150OC. for several hours furnished on subsequent distillation with water a very appreciable quantity of di-iodide of methylene. A comparative experiment in which I followed the plan recommended by Boutlerow (1 eq. of iodoform and 3 eqs. of ethylatc of sodium) leads me to think that the action of heat * Cotnpt.rend. xlvi 595. yields a larger product and involves on the whole a far less troublesome operation. The inequality of the amount of pro-duct in my experiments however may possibly be ascribed to the circumstance that I have repeatedly prepared the methylene- compound by exposing iodoform to the action of heat alone while Boutlerow's process mas only once or twice adopted. The transformation of iodoform into di-iodide of methlene by one or other of these processes is strange enough and as yet remains entirely uiiexplained ;there is formed together with the methylene-compound a quantity of a brown substance the nature of which appears anything but attractive. 8. Dibrowide of Ethylene.The usual mode of preparing this compound which of late has acquired considerable interest consists in pstssing ethylene into bromine covered with a layer of water. This method is extremely tedious since in order to avoid the loss of both bro-mine and of ethylene the gas can be but slowly transmitted through the liquid. The compound may however be rapidly obtained without the slightest loss by an exceedingly simple modification of the process. A strong glass bottle of 2 or 3 litres capacity is provided with a perforated cork through which is fitted a glass tube open at both ends one of mhich reaches nearly to the bottom of the bottle whilst the other slightly projecting over the cork communicates by means of a flexible ilridia rubber tnbe with the gasholder con- taining the ethylenc.To start the operation the bottle is cletached and filled over water with ctliyleiie gast into which are then poured from 100 to 130 grm. of commercial bromine and about half that quantity of water the cork with the glass tube being immediately replaced. On gently agitating the bottle the ethylene is rapidly absorbed and on turning the stopcock of the gasholder the gas rushes into the bottle exactly as into a vacuum. If the agitation be continued a very large volume of ethylene may be thus united with bromine in an cxceedingly short space of time without the loss of a particle of the constituents or of the com- pound. As soon as the absorption becomes languid the bromine is renewed and the process continued in this manner until the accumulatioiz of the dibromide renders it desirable to interrupt 1' 2 the operation.When working upon a very large scale it is con.. venierit to insert between the absorption-bottle and the gasholder a wash-bottle filled with water or dilute potassa which serves as a gauge for the rapidity of the gas-current purifying the gas at the same time if necessary and intercepting moreover any bro-mine-vapour that may har-e risen into the iiidia rubber tube if the mixture should linve become hot in consequence of too rapid absorption. Rquantity of t-nonobrominated ethylene (bromide of yinyl) was sealed up in a glass tube with the view of preserving it. After the lapse of n night the colonrless extremely mobile liquid w8s found to have become a white porcelain-'ii!ic mass aid on opening thc tube all pressure liad disappeared.'I'he white substance was perfectly amorphous arid inodorous mid proved insoluble in water in alcohol mid in ether. When heated it was chairrecl with abundant evolution of hydrobromic acid. Analysis showed as might have been expcetec-l that the altern- tion of the monobroniinatecl ethylene had been simyly molecular. 0.2954 grm. substance burnt with chromate of lead gw'e 0*2178$ grm. of carbonic acid aid 0.0'780 grm. of water. The values corresponding to the formula C,I-f,Br are :-Theory. Experhelit. c 24 22.43 32-87 €1 3 2.80 2.93 I_ lifr 80 74-77 107 100.00 The chemical relations of broiiiide of vinyl are as yet but slightly examiiied.From its formula the body might be consi-dered as the hydrobromic ether of an alcohol homologous to allylic alcohol; this mode of viewing it however is not supported by thc general deportment of the cornixxiiiil The peculiar molr-cular transformation which it undergoes points ratIier to aldehydic relatiom aldehyde being isomeric with the alcohol in question. As in the case of aldehyde the coiiditions involving these trans- formations are utterly unknown; I have minlg tried to fix the circumstances uuder which the solid modification of bromide of vinyl is formed. In some cascs the liquid bromide was pre-served for weeks without the slightest change when suddenly the liquid was found to have been traiisforined throughout its entire mass.At one time I thought I had observed tht the presence of water favoured the metamorphosis but I hmc convinced nipsclf by special experiments that this is not the case. The change takes place as capriciously in the presefice as in the absence of' watcr. It cleserves to be noticed that other bodies derived from ethylene by substitution are prone to similar trsusformations. Thus R e gn au1t * many yeam ago olrmrved analogous pbeiio- men&in the case of dichlorimted ethylcne The reaction generally used for the preparation of this com- pound is so siniple and elegant that it would be difficiilt to propose a better inethod. Indeed all the processes which have been sug- gested differ only as to the proportions of iodine phosphorus and alcohol or as to the manner in wliicli these substances are to be brought into contact with each other.Iodide of ethyl bcing extensively .used as substitution-material in all laboratoricg every observation which is calculated to facilitate the preparation of this body may prove acceptable The common plan of gradually introducing fragnients of phosphorus into the mixture of alcohol and iodine has the disad-vantage of occasionally giving rise to powerful reactions involving considerable loss of materials even when great care is taken to add the pliosphorus slowly and in little fragments. Tliis incon- venieiice may be readily avoided by introducing the phosphorus together with about it fourth of tlie alcohol to be used into a retort connected with an efficient cooler into the tubulus of w'hicli is fitted a glass globe proviclccl with tube and stopcock.-f The rest of the alcohol is then poured upon the iodine and tlie solu-tion thus obtained is introduced through the globe into the retort tvhich is heated on a sand-bath or in a water-bath.Iodine is but sparingly soluble in alcohol but excessively so in iodide of ethyl; it is therefore only necessary to pour thc first portion which distils upon the residuary iodine which is readily dissolved and to allow the concentrated iodine solution thus obtained to flow through the globe into the retort where it is instantaneously converted into iodide of ethyl. This process is especially conve- riient when the iodide of ethyl is to be prepared on a rather large scale.In this case I find it convenient to dissolve the iodine at once in iodide of ethyl and to introduce it slowly through the globe into the retort The stopcock being appropriately adjusted the process requires but little attention and being continuous yields a very large product in a comparatively limited time. The iodide generally distils at once perfectly colourless and requires only to be washed with water in order to become free from traces of alcohol. It deserves to be noticed that the process may be carried out in a very moderate-sized retort since there is only a very limited portion of material at a time under operation. Convenient proportions for iodide of ethyl are 1000 grammes of iodine 700 grammes of alcohol of spec.grav. 0.84 (83 per cent.) and 50 grarnmes of phosphorus. From 96 to 98 per cent. of the theoretical quantity of pure iodide of ethyl are obtained. It deserves to be noticed how small a quantity of phosphorus is necessary for the etherification of the iodine the quantity stated being less than one-half of the amount given in the majority of prescriptions. Iodide of methyl and iodide of amyl may be prepared in the same manner. In the case of iodide of methyl the following proportions have been found by experiment to work well. 1000 grarnmes of iodine 500grammes of methylic alcohol (the fraction boiling below 74*) and 60 grarnmes of phosphorus. The product owing to the volatility of the compound is somewhat less than in the previous case amounting to from 94 to 95 per cent.of the theoretical quantity. 11. On the deportment of Cyanate of Ethyl with Btkykute of Sodium. In a former note* I have stated that cyanate of ethyl when heated with ethylate of sodium is converted into triethylamine and carbonate of sodium. lout I Imve pointed out at the same time that owing to the facility with which the ethylate of sodium Chein. SOC.,(&I. J ,Y 20 undergoes decompasitioii at ’eompnratively moderate temperatures the process in question appeared to be of limited application. I have lately had occasion to resume the study of cyanate of phengl which I described several years ago.* It appeared to me to be af some interest to apply the above reaotion to the prepara-tion of triphenylarnine On performing the experiment I found however that phenylate of sodium and cyanate of plienyl give rise to a different reaction; no triphenylamine was obtained in this process This unexpected result iuduced me to repeat the experiment on the aetion of ethylate of sodium upon cyanate of ethyl.1 have found that in this CaSe likewise the reaction frequently assumes a form different from that which I had previously observed aid which excludes the production of triethylarnine. I am engaged in the study of this transformation the result of which I propose ta lay before the Society on some future occasion. Before the nature of this interesting compound had been finally established by B er the1 ot’ s remarkable inquiries it had been freqqently surmised that the mponification of the several fqtty bpdies which are found in nature did not irivariably furnish the $&mekipd of glycerin.This view appeared to receive nem support in the researches of Wur%ra,who has rendered it probable that glyceriu is but the type of a Glass of homologous triatomic alcohols As a pontribution towards the eluoidation of this question an experiment may be briefly mentioned which arose from a conversa-tiou with my friend Mr. George Fergnson Wilson the technical director of the great establishment well known as Price’$ Patent Candle Company. &Iany hundred weights of glycerin &ga weekly separated in these works by simple steam-saponification from a eoiisiderable variety of fatty bodies ; and My Wilson who has studied with predilection the preparatisn asd purifioation of glycerin on a large scale has acquired a suin of practical information upon this subject such as will not easily be found again.To my question whether there is inore than one kind of glycerin Mr. Wilson replied that in his opinion a11 the fatty bodies wliich he had examined contaiviccl the same * Chem. Soc. Qu. J. ii 363. variety of glyccriii with tlie exception of cocoa-nut oil the g1;tycerin-lilre constituent of which differed iii many respects SO mucli from ordinary glycerin that lie mas inclined to consider it as a special variety. Since this question admitted of a simple experimental solution Xi*. Wilson kindly supplied me with a quantity of glycerin obtained by the saponification of cocoa-nut oil.This substance although prepared iii the same manner differed in colour and odour from the glycerin furnished by other fatty substances. But notwithstanding the colouring matter and an odorous principlc which adhered with great pertinacity it was not difficult to identify the cornponiid under examination with ordinary glycerin. Distilled with iodide of phosphorus it ftxmished iodide of allyl which exhibited the same boiling point as that obtained from ordinary glycerin and was also transformed under the successive irifluence of oxalate of silver and ammonia respectively into oxalate of ally1 and allyl-alcohol. These experiments appear to solve tlie question as far as cocoa-imt oil is concerned. 13. Dinitrotoluic Acid.The nitro-substitutes of the aromatic acids are but slowly transformed into dinitro-compounds. -Whoever has made the experiment in thc benzoyl-series has had an opportunity of experiencing this difficulty. The same remark applies to the toluyl-series Noad,* to whom ~1-eare indebted for the first know- ledge of this group found that nitrotoluic acid may be dissolved in a boiling mixtnre of nitric and sulphuric acids without undergoing any alteratioii. TYhitst studying some reduction plienomeiia of nitro-compounds I felt an interest in procuring if possible a small quantity of dinitrotoluic acid and by my desire Mr. William Temple has prepared this substance. Pure nitrotoluic acid was digested for two days with three times its weight of equal parts of fiming nitric aid sulphuric acids.The solution being mixed with an equal volume of water a crystallization of dinitrotoluic acid was obtained on cooling. It was waslzecl recrystallized from water and sub-mitted to analysis. I. 0.582 grm. of acid burnt with oxide of copper gave 0.908 grm. of carbonic acid and 0.152 grin. of water. * 31~~. C~I,S(C,,111. 43’1 11. 0-396grm. of acid gaye 0.61& grm. of carbonic acid and 0.103 grm. of water. Thebe numbers prove that the acid consisted of dinitrotoluic :reid CbHGN2OG = C,[ll,(N02),10 in 8 state of purity. This result is fully confirmed by the analysis of the silver-salt which is obtained in the form of a white precipitate on addition of aiitrate of silver to a solution of dinitrotohate of ammonium.The silver-salt contains I. 0'609 grm. of silver-salt gave on combustion 0643 grm. of carbonic acid and OW4 grm. of water. 11. 0.130 grm.of silver-salt gave 0.042gvm. of silver. Theory. fi;xperiment. I. 11. c8 96 28-83 28.78 - HEl 5 1-50 1.71 - ATa 0 Ag 28 96 108 8-1,11 23-83 32.43 -__c 1_1 32.30 _. - -/c___ 333 100.00 Few bodies have fixed the attention of chemists more generally than indigo. But have their experiments led to a satisfactory view regarding the nature of this colouring matter ? The brilliant labours of Erdmnnii and of Laurent have brought to light a rich HOFMANN harvest of the most interesting derivatives of indigo but they ham left us in uncertainty with regard to the constitution of this group of eompaunds.With the hope of throwing some light upon this subject 1have endeavoured to eliminate the nitrogen from these compounds by processes likely to act without producing too powerful alterations. The mode o€ action peculiar to nitrous acid appeared to promise some results; and since indigo owing to its insolubility is but little adapted to this reaction I have made some experinients with isatin which is so closely allied to indigo. Supposing isatin to undergo a transformation analogous to that first observed by Piria in similar cases and consisting arithme- tically in the exchange of HN for 0 there appeared some hope of obtaining in this manner iiaphtalic anhydride and of thus open-ing a passage from the indigo-group into the naphtalin-series.Isatiii . . C,€I,N02. Naphtztlic anhydride . C,H,O,. The history of these two bodies prcsents some features which conferred a degree of probability on such a transformation. Both isatin and naphtalic anhydride readily assimilate the ele- ments of water being converted respectively into isatic and naphtalic acids which when submitted to the action of alkalies give both rise to the formation of phenylic derivatives isatic acid yielding phenylamine arid naphtalic acid being converted into hydride of phepyl (benzol) . Experiment however has not confirmed my anticipation and it might seem superfluous to waste another word upon the subject; nevertheless I will briefly mention the result of this unsuccessful experiment since it may probably save some trouble to others.When studying the deportment of isatin with nitrous acid I observed the following facts. If finely powdered isatin be sus-pended in from ten to twenty times its weight of water and the misture be then submitted to the action of a current of nitrous acid (disengaged by the action of arsenious acid upon nitric acid and partially freed from nitric acid by sending it through an empty wash-bottle) the liqliid at once begins to effervesce and the isatin is soon entirely dissolved. The nearly colourless solutioii invariably contains a considerable quantity of nitric acid generated by the contact of the nitrous acid with the water. To avoid the action of this acid upon the product of the transformation of the OX ISATIN.’a5 isatin the liquid mixed Kith much water was evaporated upon the water-bath the water being repeatedly renewed so as to prevent the iiitric acid from getting concentrated. The liquid thus evaporated deposited crystals of an acid which once or twice recrystallized from boiling water appeared to be perfectly pure. On analysis the following numbers mere obtained-I. 0*4305grm. of the acid gave 0.7203 grin. of carbonic acid and 0.1098 grm. of water. IT. 0.3164 grm. of the acid gave 0.5306 grm. of carbonic acid and 0.0874 grm. of water. These numbers lead to the expression which is the formula of nitrosalicylic (indigotic) acid. Theory. Experiment. I. Ir. C 84 45.90 45.60 45.73 H 5 2.73 2-81 2*86 N 14 7.65 -0 so 43.72 -L -c-183 lQO*OO Assuming the iiitrosalicylic acid to be a product of osidatian of the body directly formed from isatin under the influence of uitrous acid the solution before evaporation was neutralized by means of nn alkali.The result remained the same. la another experiment pea-sizcld pieces of marble were introduced into the mixture of water and isatin beEore the iiitrous acid nas passed in order to rcrnove the free nitric acid as rapidly as it mas formed. In these experiments likewise nitrosalicylic acid was obtained. It need scarcely be mentioned that the acid derived from isatin possessed all the properties of nitrosalicylic acid prepared by the ordinary method ;it exhibited more especially the characteristic coloration with perchloride of iron.When the liquid obtained by treatment with nitrous acid was evaporated witliout liaving been previously mixed either with water or with an alkali the isatin as might have been expected was transforniecl into trinitrophenylic acid. This acid was suffi- ciently characterised by its properties and by the aiialysis of its well-known difficultly-soluble potassium-corr_l,onnd. 0.3399grm. of the potassium -salt when buriit with chromatc of lead gave 0.3293 grm. of carhonic acid and 0.0230 grm. of water. The formula CGH,KN,O7 folloving values,-Theory. Experiment. C6 72 26-97 27.14 H2 2 0.75 0.76 I< 39 14-63 -I_ N 42 15.73 0 112 41.95 -Some gtiu-cotton prepared iu. the establishment of Messrs.Hall soon after SchGnbein’s discovery and taken out of a cartridge intended for blasting had been preserved by my friend Dr. Percy since 1847 in a glass bottle provided with a glass stopper. After some time red vapours had appeared in the interior of tlie bottle and thc cotton had crumbled down to a loose powder. When lately the bottle was again examined the powder was found to be converted into a light brown semi-fluid gum-like mass nhile the side of the bottle had become coated with a net-work of fine needles. It was not difficult to collect a sufficient quantity of these crystals ; they exhibited all the chrtrac- ters of oxalic acid. In order to fix their naturc by a number they were converted first into the ainmonium-salt arid then into the silver-salt.0.2420 grm. of silver-salt gave 0.2275 grm of chloride of silver = 70-74p.c. of silver. Oxalate of silver contains 71.05 p.c. of silver. The viscid mass into which the bulk of the gun-cotton had been converted exhibited all the properties of ordinary gum; it was likewise interspersed with crystals of oxalic acid. 16. Expe?*.ime?ztnl ilkstration of tlte Composition of Amrnofaiu iiz Lectures. The deconiposition of ammonia by the spark-current exhibits in a conspicuous manner the condensation which accompanies the transformation of a niixture of liydrogcn and nitrogen iiito ammonia. It is more difficult to illustrate the relative proportion of the nitrogen and hydrogen which exists in ammonia. The €01- lowing experiment elucidates thongh indirectly this relation.A glass tube from 39 to 40 inches in length am1 9 of an inch in width is sealed at one end and divided without particular care into three equal parts which are convcnieiitly marked by papar or by india-rubber rings. The tube is then filled over water with pure clilorine and at once transferred into a test-glass half filled with mercury and half with coScentrated solution of ammonia. Tn this manner a layer of ammonia one or two inches in lreiglit and separated from the bulk of the liquid by mercury is collected in the tube. 1% lively reaction inimediately sets in the mercury rises and thc ammonia-solution floating 011 the metal effervesces with evolution of nitrogen while tlic chloriiie disappesra dense white clouds of chloride o€ammoniuni being formed.According to the equation-II,N + 3c1 = 3HC1 -/-N the 3 volumes of chlorine should be replaced by 1 iiolunie of nitro-gen and this result is actually observed. At the common tern-peratrne hornever the reaction is but slowly accomplished the disengagement of nitrogeir from the solution of ammonia becoming slower and slower but often continuing for hours. On tlre other hand the decomposition is instantaneous if tlie tube be gently inclined and the liquid floating upon the mercury be heated to ebullition. To complete the experiment it is only necessary to transfer the glass tube into a higli cylinder filled with water in which the inner and outer liquids may become level when the 3 volumes of chlorine originally filling the tulle are found to be very accurately replaced by 1 volume of nitrogen gas.Supposing the compositioii by volume of hydrochloric acid to bc known the composition of ammonia is fixed by this observation. The experiment furnishes moreover an instructive illustration of the volnme-ea_ui~ale:ice of cliforine fi yd rogen acd nitrogen HOPMANN ON SEPARATION 17. How to exhibit the hzflarnmability of Anmo~ziic. It is well known that ammoniacal gas cannot be inflamed in atmospheric air but will burn in oxygen gas with a greenish-yellow flame. This flame may be shown by allowing the gas to issue from a bent jet into a vessel containing oxygen. There is however some difficulty in lighting the gas and under the most favourable circumstances the phenomenon is very ephemeral.To avoid this inconvenience the inflamtiinbility of ammonia is gene- rally exhibited by sending a current of the gas into an ordinary flame the ammonia-gas being allowed to issue from the delivery tube into the lower opening of an Argand gas-burner provided with a glass chimney. The gas burning low and almost invisibly the high lainbent ammonia-flame becomes very conspicuous. The phenomenon may however be observed in a purer and much more brilliant form when a vide-mouthed flask containing a strong aqueous solution of ammonia is heated upon a sand-bath and a rapid current of oxygen gas from a gas-holder forced through the boiling liquid. The mixture of oxygen and ammonia-gas thus formed may be lighted and burns at the month of the flask with the characteristic greenish-yellow flame n hich continues until the ammonia is expelled from the liquid.18. Separation of Cadmiumfmua Copper. Having had occasion to perform some experiments on the rela- tive merits of the several processes which have beeii suggested for the separation of cadmium from copper I was led to observe ti property of sulphide of' cadmium which I do not find noticed in analytical manuals. Sulphide of cadmium dissolves with the greatest facility in boiling dilute sulphuric acid which has no effect upon the sulphide of copper. On precipitating by suIphuretted hydrogen a solution containing iiot more than 1 milligrammc of cadmium mixed with 1000 milligrammes of copper and boiling the black precipitate for a few seconds with dilute sulphuric acid (1 part of concentrated sulphuric acid and 5 parts of water) a colourless filtrate is obtained in which an aqueous solution of sulphuretted hydrogen produces an uninistalrable precipitate of yellow sulphide of cadmium.Another solution of the same com-position was mixed with an excess of cyanide of potassium and treated with sulphuretted hydrogen gas. A distinct yellow OF ARSENIC FROM ANTIMONY. coloration was observed a deposit likewise took place but so slowly that; in delicacy the former experiment appears to have a considerable advantage especially since a solution of pure copper in cyanide of potassium also gives rise to b yellow coloration when submitted to the action of sulphuretted hydrogen.19. Separation of Arseizicfrom Antimony. The separation of these two metals which presents uausual difficulties has been a task of predilcction with chemists and a great number of processes have been suggested the majority of which it cannot be denied admit of improvement. Among the many methods the one which is based upon the dissiniilar deport- ment of arsenetted and antimonetted hydrogen with nitrate of silver deserves to be favourably mentioned the former as is well knomn yielding arsenious acid which passes in solution H,As + GAgNO + 2H,Q = OIHNQ + 6Ag + IZAsO,. the latter giving rise to the formation of antimonide of silver H,Sb + 3 Agh'O = 3HN0 + hg,Sb which is insoluble in water. This process presents no difficulty as far as the arsenic is concerned which may be recognieed in solu-tion by ammonia if there be an excess of silver or by sulphuretted hydrogen if the silver has been entirely precipitated.It is far less easy to find according to this process minute quantities of antimony in the presence of large quantities of arsenic the silver- compound of antimony being mixed with a bulky precipitate of metallic silver. By treating this precipitate as might readily suggest itself TI ith hydrochloric acid there dissolves together with antimony a small quantity of chloride of silver which is bufficient to darken the precipitate produced in the solution by sulphuretted hydrogen to such a degree as altogether to mask the presence of antimony. This inconvenience may easily be obviated by boiling the mixture of silver and antimonide of silver after the arsenious acid has been carefully washed out by boiling water with tartaric acid which dissolves the antimony alone.The solution thus obtained yields at once the characteristic orange- yellow precipitate with sulphuretted hydrogen. In some experiments made with the view of testing the delicacy of this process 1 part of antimony in presence of 199 parts of arsenic and %ire verscf 1 part of arsenic together with 199 parts of-antimony could be easily detected. I& cii with minute quan- tities the process proved successful iiiasmuch its S milligramnies of' either metal in the presence of 100 times the amount of the other could be satisfactorily exhibited.In evolving tEic hydrogen.. compoiincls of arsenic and antimony care must be talcen to add as little nitric acid as possible to the liydrocliloric acid USCC~in dis-solving tlic sulphides of the metals since the presence of even moderate quaiititics of this acid greatly iiiterferes with the free disengagement of the gases. If there be tin with the arsenic and antimony this metal will be deposited upon tlie plates of zinc used in evolving the hydrogeii from which it may be meclianically detached dissolved in hydro- chloric acid and tested by the usual processes. The water used for analysis was collected November 11 1858 The water p-inipecl up from the id1 is perfectly clear and colourless and almost inodorous. It has a distinctly saline taste and effervesces on agitation exliiliitiiig the presence of a coild siderable quantity of free carbonic acid.The water contains in addition to carbonic acid a minute trace of' an iiiflarnrnable carbo- netted hydrogen. The presencc of the latter becomes perceptible if a considerable quantity of the water be heated to ebullition and tlie gases expelled be passed through a solutioii of potassa. The gas not absorbed is a mixture of atmospheric air with the car-bonetted hydrogen ;it burns owing to the prepoiiderance of the air with n pale scarcely visible flame. On standing more readily on boiling the water deposits a yellowish sediment consisting of ccrbonate of callcium carbonate of magnesium sesquioxide of iron and organic niatter. Temperature of the water lZ*C tJie temperature of tlie air* being nearly thc same.Specific gravity of the water =l*C06. The analysis was performed iii the usual manner; only tllp determination of the bromine requires a passing notic?. In determining this element I have availed myself of tho method of imperfect precipitation. According to the observn- tions of Lyte and of Field nitrate of silver produces in a mixtiire of chloride bromide and iodide a precipitate first of THE SALINE W-iTER OF CHRISTIAN MALE’ORU. iodide and then of bromide and a precipitate of chloride only after the whole of the iodine and bromine have been separated ;-a method of separating chlorine bromine and iodine based upon this deportment has been proposed by the latter chemist.The amount of iodine present in the watcr of Christian Malford is so exceedingly small that the quaiititative cleterminatioii appeared useless. The task mas therefore limited to the cletermi- nation of the bromine. For this purpose 28 litres of the water ere evaporated to dry-ness and the saliiie residue was exhausted with difnte alcohol. The alcoholic liquid when submitted to distillation left a saline mass which was dissolvecl in a mmll quantity of water. This solution was measured and divided inlr two rqunl parts eneh of which represented the extract of the saline residm of 14 litres = 14084 grarnmes of the original water contaiiiing the vhofe of the bromidcs aid part of tlie chlorides Eacli of the liquids thus obtained mas precipitated by a silver-solution containing 0*4258 grslmmes of pure silver whereby the whole of the bromine and part of the chlorine was thrown down.The ti170 precipitates weighed respectively 0.6355 (I),and 0.6360 (11)grammes. If P represent the weight of the niixecl precipitate and x the amount of chloride of silver in it then P-x is the quantity of bromide of‘silver and if the total amount of the silver in the pre- cipitate be represented by tS then whence S -0.5745 P x = - 0.1781 By substituting the esperimeiital values for X and P in the above expression we find I. IT. Chloride and bromide of silver (by experiment) . . . . 0.6355 0.6350 Chloride of silver (by calcula-lation) . . . . . . . 0.3876 0.3593 Bromide of silver.. . . . 0.2’779 0.2757 Corresponding (in 14084 grms. of water) to bromine . . O*ll82 091273 Or in 1000 grms. to . . . . 0*0084 0.0083 TOL. XITT. < IIOPMANN ANALYSIS OF Direct results of analysis calculated to 1000 grarnmes of water. a. BASES. Experiment. I *. .. 0.0035 0.4234 0.1897 6.9600 0.863 6.097 t. 11. ...... 0.0035 0.4241 0.1903 6.8800 0.897 6.983 Mean.. , 0.0035 0.4238 0.1900 6.9200 0.880 6.040 b ACIDS (or denzents replacing them) Sulplinric Rromine Carbonic Carbonic Acid comliineit Carbonic Chlorine. trg:ofSilica. hid fi ee as Carbonate of EXP. anil Calcium. Acid. Iodine. combined. on3 Magnesium. Acid free. __I__.----.i. .... 0.2464 4.5630 0 *0084 0 -0150 0 *2921 0 -1050 0 1871 IT. ....0-2452 4 -5570 0.0083 0 -0145 0 *3164 0 *lo72 0 2092 Mean ,. 0.2458 4 -5600 0 *0084 0 +0148 0 -3043 0,1061 0,1982 c. RESIDUE LEFT ON EVAPORATION. Experiment. Mineral Residue. Organic Matter. Total Residue. I. ....*... a -2000 0 *0200 a -2200 JI. ........ 8*1900 0 *0200 a *2100 ---.I-----nifean ,.,. . . 8,1950 0 -0200 8 -2150 THE SALINE WATER OF CHRISTIAN MALE’ORD. VERIFICATIONS. a. VERIFICATION FOR LIME. __ .-__ -Lie precipitated Lime left in solutiou on after Total Total Experiment. ebullition. ebullition. bY bjr (Carbonate of (Sulphateand Chloride Calculation. Experwept Calcium.) of Calcium.) I-I I. . . ,. . . 0.1285 0-2895 IT. ...... 0 *1307 0.2556 0 -4163 0,4241 Mean ,. .. 0 -1296 0 ‘28’76 0,4172 0,4238 6.‘VERIFICATION FOB MAGNESIA Experiment. Magnesia ebullition. (Carbonate of Magnesium.) precipitated 011 Magnesia left in solution (Chloride after ebullition. of Magnesium ) Total Calculation.by Fatal Experiment.by ------___I I. ......I 0.0022 I 0.1852 1 0.1814 I 0.1897 11. ..*... 0 ‘0025 0 *1863 0 *1888 0 -1903 --_I_--- Mean ,. .. 0,0024 0 -1857 0 ~1881 0.1900 SALINECONSTITUENTS. In one gallon In 1000 grammea (70,000grains) of water. of water. _. _. Grammes. Grains. Su’fphnteof calcium . . 0.4179 29.253 Cmbonate of calcium . . 0.2314 16.198 Chloride of calcium . . 0.2289 16.023 Carbonate of magnesium . . 0.0050 0.350 Chloride of magnesium . . 0.4413 30.891 Bromide of magnesium (with traces of iodide of magnesium) 0-0096 0.672 Carbonate of iron .0.0051 0.35if Chloride of potassium . . 043800 61.600 Chloride of sodium . 6*0400 422*800 Silica . 0.0148 1.036 Organic matter . . 00200 1-400 8,2940 580.580 G2 The water contains 29-03 cubic inches in the gallon 01' 104.6 cubic centimetres in the litre of free carbonic scid. Tlic quantity of carbonic acid was determined at the well. It deserves to be mentioned that the water for this purpose was pumped up whereby probably a minute quantity of gas was lost. My thanks are due to Mr. 33 Millar of Christian Malford for his help in collecting the water and to Dr Leibius for his assist- ance in pe~forr~ing the experiments. 21. SpontaneousDeconposition of Chloride of Lime One morning (I think it was in the summer of.' ZSSS) when entering my labor:itory which I had left in perfect order on the px*evious evcning I was surprised to find the room in the greatdst confxxsion.Broken bottles and fragiue11ts of apparatus lay about several window panes mere smashed and all the tables and shelves were covered mitli a dense layer of white dust. The latter was soon found to be chloride of lime and ftirnished without difficulty the explanation of this strange appearance. At the conclusion of the Great Esliihition of 1851 31. Ktihl-rnann of Lille had made me rz present of the splendid collection of cheinical preparations mliich he had contributed. The beautiful large bottles were for a long time kept as a collection; gradually however tlieir contents prored too grezt a temptation and in the course of time all the substances had-been consumed.only one large bottle of about 20 litrcs capacity and filled with chloride of lime had rcsisted all attacks; the stopper had stuck so fast that nobody could get it out ; and after many unsuccessful efforts-no one rcnturing to indulge in strong measures with the handsonic vessel-the bottle had at last found a place on one of the highest shelves of.' the laboratory where for years it had remained lost in dust and oblivion until it had forced itself back on our recollection by so energetic an appeal. The explosion had been so violent that the neck of the bottle was projected into the area where it was found with the stopper still firmly cemented into it. I have not been able to learn mlrether similar cases of the spontaneous decomposition of chloride of lime have been already observcd.CARBON LN COAL GAS 22 Bisukhide of Cnrbon iiz CoaE Gas. It is well known that coal gas even when submitted to the most improved processes of purificntion retains a minute quantity of a sulphur-compound which yields sulphurous acid mhcn thc gas is burned. A commission having been appointed fur the purpose of rcportings to the Lords of the Committee of Privy Council on Education on the lighting of picture-galleries by gas and on any precautions (if necessary) against the escape of gi1s and of the products of its combustion the writer of this note undertook a few experiiiicnts with the view of determining the amount of sulphur generally present in the London coal gas.The object of the inquiry being to ascertain the quantity of sulphurous acid capable of being formed by the combustion of the gas an exceedingly small jet of gas carefully washed with acetate of lead-which showed the absence of sulphuretted hydrogen- and measured by au accurate experimental meter wits burned in a large two-necked glass globe. Through one of the necks the gas tube was conveyed into the globe whilst the other fitting iiito a condenser carried off the product of combustion into a two-necked receiver. To establish a current of air tlie receiver was eorinected with a water-current aspirator a couple of Woolfe's bottles containing water or dilute ammonia being inserted for the pur-pose of fixing any trace of sulphurous acid wliich might escape condensation with the water in the receiver.The experiment being terminated the liquids in the receiver and in the mash- bottles were uuited oxidized with chlorine and precipitated with chloride of barium. Experinients in July 1859. Order of Experiments. 1. .. . . . 1-98 0 0630 0 -437 6 -74 15 433 11. ....*. 2 0 0840 0 *577 8 -90 20 371 111. . .... 2 0 *0630 0 '433 6 *68 15.278 IT.,.,... 2 0 -0i40 0 *508 7 84 17 -944 t, Mean ..,. .. 1 0 488 7 -54 I7 *256 * Rcport on the subject of Liglitiiig Picture Gallerics by Gae by Professors Faraday Nofmsnn,and Tyuclsll Ah licdgrave R.A and Capt. ft'owke R,E. HOFMANX OX ‘YHE Experiments in December 1859 and January 1860.Order of Experiments. Amount of Snlpliiirin 100 cubic feet. Graiiis. 1 -Grammes. v. .... TI.,... 0 *osso 0-0953 0 *611 0 *654 9 *43 10 -10 21,585 23 -111 VIT. ,. . . VIII. . . 0*0975 0*0935 0 -669 0-642 10*33 9 91 23 644 22 *677 _I_-- Mean .,, .. 0-64.1 9 *94 22,754 I These experiments show that the amount of sulphur remaining in the Londoh gas after the removal of the sulphuretted hydrogen is very small and that in winter it is somewhat greater than in summer. This may possibly arise from the enormously increased production of gas during the winter months when it will be more difficult to regulate the several processes involved in its manufac- ture. But the result may also be purely accidental arising from a change in the nature of the coal used etc.A much more extended series of experiments would be required to decide this question. It has long been assumed that the sulphur in purified gas exists in the form of bisulphide of carbon the conditions for the genera- tion of this compound being in fact given in the ordinary process of producing gas. That coal gas really contains bisul- phide of carbon was first elegantly proved by Vogel,* who at the suggestion of Baron Liebig passed a current of purified gas through an alcoholic solution of potassa when xanthate (sulpho- carbonate) of potassium (K(C,H,)CS,O) mas formed which pro- duced in copper-solutions the highly characteristic yellow precipi- tate of xanhate of copper and yielded when boiled with a few drops of nitrate of lead in the presence of free potassa a black deposit of sulphide of lead.When engaged in the above inquiry I repeated Vogel’s experiments which I can confirm in every parti- cular. The amount of hisulphide of carbon in the London gas is however so small that a very large volume must be passed through the alcoholic solution of potassa in order to produce a sufficient quantity of xanthate of potassium. After a cubic foot of gas had been passed through alcoholic potassa in a bulb apparatus the * L i e big’s Annaleri Ixxxviii 369. C€IANGES OF GUTTA PERCI-1.4. solution gave with sulphate of copper a leek-green precipitate in which the presence of xanthate was but imperfectly indicated. Only after passing several additional cubic feet the yellow colour became more distinct although still masked to stlme extent by the hydrated protoxyde simultaneously precipitated.On the other hand the black precipitate of sulphide of lead mas obtained without difficulty even after the passage of one single cubic foot of gas. But the presence of bisulphide of carbon in coal gas may be es- hibited even more elegantly and with greater precision by means of trie~~~~~os~~ine, which produces with the bisulphide a com-pound crystallizing in splendid prisms of a ruby colour. This body is so characteristic and forms with so much facility that biswlphide of carbon has become a most valuable re-agent for triethylphosphine and its homologues. The idea naturally sug-gested itself to employ the phosphorous-base for the detection of bisulphide of carbon in gas.On distilling a considerable proportion of coal -gas-benzol I had separately collected a small fraction which came over in the commencement below 65O. When mixed with triethylphosphine this liquid solidified into a mass of the well known ruby crystals. Four or five drops of triethylphosphine were dissolved in ether the ethereal liquid was introduced into a bulb apparatus and a current of coal gas allowed to bubble through the solution. When 0.2 of a cubic foot had passed the liquid had assumed a distinctly red coloration the intensity of which increased as the passage of the gas and the evaporation of the ether continued. After 0.8 of si cubic foot had pawed the whole of the ether had evaporated and the inaer surface of the bulb-apparatus was lined with a beautiful network of the ruby crystals 28.Remarks on the Changes of Gutta Pwcha under ‘Tropical TnfEuences. [From & Report addressed to Sir W. B. O’Shaughnesay Director-General of Telegraphs in India.] The peculiar change which gutta perclia undergoes when in contact with air for some time is well known this substance gradually becoming brittle and ultimately losing all coherence. T’his effect was experienced on an undesirable scale in conatruct- ing the East Indian Telegraplis. Enormous qurtiitities of gutta percha bccame in a comparatively short time entirely useless involving a loss of thousands of pounds. At the request of Sir W. B. O'Shaughnessy I have made a few experiments with the gutta percha thus altcrcd the results of which were recalled to my mind by tIic researches on the alteration of gutta percha lately published by Oudeman.It may be of some interest briefly to inention the analytical results furnished by the chauged material submitted to me for examination. The specimcns sent home from India formed a brown exceed- ingly brittle substance softening to a plastic moss in boiling water. Since the gutta percha existing in commerce does not always exhibit the same characters it was of some importance for the inquiry that a quantity of the original unchanged substance with vhich the wires sent out to India had been coated was likewise placed at my disposal. In their deportment with solvents the changed and unchanged gutta percha exhibited a marked difference.Whilst the latter proved to be pzrfectly insoluble in strong alcohol the changed gutta percha was in a great measure taken up by this solvent. By treating the changed material first with cold then with boiling alcohol and ultimately with ether three substames were obtained which aithough very much alike in their physical properties differed considerably from each other in their chemical composition. T.-Szcbstance soluble in cold Alcohol. Cold alcohol readily attacked the outer surface of the coating and dissolved a coiisiderable portion. On evaporation a brown resinous mass remained behind which ,was dried first over sul- phuric acid and ultiinately at 100"; at wliich temperature it readily fused.*The fused mass solidified on cooling to a brittle substance yielding a highly clectrical powder and exhibiting on combustion the following percentage composition I. 11. Mean. Carbon. . . . 62.941 62-64! 62.79 Hydrogen . . 9.22 9-36 9.29 Oxygen . . . 27.84 28.00 27.92 -7- I c\o*oo 1 OU~OO 100.00 IT.-Substance soluble in boiling A7cohol. By treating with boiling alcohol the residue of the previous operation which had ceased to yield anything more to cold alcohol a fiesh quantity of substance was obtained in solution. The alcoholic liquid on evaporation left a residue very similar to that of the previous operation which when dried in the same manner furnished on analysis the following numbers.I. 11. Mean. a b Carbon . 68.13 67.29 67.72 Hydrogen. . 10.01 10.18 10.09 Oxygen. . . . 21.86 22.53 22.19 100*0O 100~00 100*00 111.-Substance insoluble in coEd and in boiling Alcohol. The residue left after repeated treatment with boiling alcohol dissolved in ether a few mechanical impurities remtiining behind. The ethereal solution gave vith alcohol a precipitate which dried ’up to a yellowish powder becoming highly electrical by trituration and caking when gently heated. It had the general characters of gutta percha being merely somewhat deeper coloured and less plastic. When analysed it furnished numbers nearly agreeing with those which were obtained by several observers for gutta percha Carbon . . 88.12 Hydrogen .12*39 The body last analysed mas obviously unchanged gutta percha; a view which is also supported by its soluliility in chloroform and benzol. The substance in question differed from specimens of gutta percha investigated by others and espccidly from that which Payen coiisiders the pure gutta percha by its solubility in ether The original substance with which the wires had been coated was however likewise soluble in ether. It cannot therefore be doubted that gutta percha exists in several modifications. The experiments which I have qnoted prove that the changes which gutta percha undergoes in contact with air depend upon oxidation. Unchanged gutta percha is free from oxygen; the product dissolved by cold alcohol contained nearly 28 per cent.HOFIh4NN ON THE CHAX'GES OF GUTTA PERCHA. and that soluble in boiling alcohol still more than 22 per cent. of oxygen. 1 need not mention that I am far from believing that these oxygenated substances are definite chemical compounds. Their mode of preparation altogether precludes such an idea the object of the experiments having been simply to establish the fact of oxidation having taken place. That the changes of gutta percha are due to the absorption of oxygen is countenanced by the expe- rience of this substance having been lrept for years under water without undergoing any alteration.

ISSN:1743-6893    

DOI:10.1039/QJ8611300051

出版商:RSC    

年代:1861

数据来源: RSC

摘要:

HOFAL4NN ON THE CHAXGES OF GUTTA PERCHA. On the CarBonates of Alumina Ferricl Bxide and Chromic Oxide. By James Barratt Esq. (Abstl.mt.)* THEcomposition of the precipitate produced in solutions of sul-phate or chloride of aluminium by alkaline carbonate8 has been varioutdy stated a8 follows :-According to Huspratt (Ohem. Soc. Qu. J. ii 216) it is 3&03 . 2C0 +4HO H. Rose (Pogg. Ann. xci. 462) , A1,03 3H0 -I-HH,.CO,+HO %an lois (Ann. Ch. Phys. {3] xlviii. 502) , 8840,. CO + 8H0 Walfwe (Chem. Gaz. 1858 410) , 3A1 . 2C0 +9HO From experiments made by the author of this paper in Dr. Muspratt's laboratory it appears that the precipitate formed by carbonate of soda in a solution of chloride of aluminium (the mode of preparation adopted by Wallace) after being washed and dried then triturated with water again washed and dried over sulphuric acid consists of hydrate of alumina perfectly free from carbonic acid a result which agrees with the statement of Saussure (Gmelin's Handbook iii.308.) -. Car-bonute of Chmini~ Oxide has been analysed by several chemists. According to Berzelius (Tdt6 iv. 427) it is 4Cr203. C0,+3HO Y3 Meissner (Gilb. Am. lx. 366) lOCr,O . ?'CO,+8HO Langlois (loc. cit.) >) 2Crz03 . CO + 6HO Le fort (Compt. rend. xxvii. 269) 9) CrzOs . COZ+4HO Wltllace (loc. cit.) I * This paper is pnblishcd in fidl in the Chemical Hew 30.10 13. 110. UARRATT ON THE CAiZBONATE OF ALUXINA ETC. 91 Mr. Barratt's experiments confirm the result obtained by Lefort and Wallace.Carbonate of Ferric Oxide.-Soubeiran (Ann. Ch. Phys. [2] xliv. 326) found that the precipitate thrown down by alkaline carbonates from ferrous salts after thorough washing and exposure to the moist air of a cellar for six months no longer contains ferrous oxide but consists of 71.4 p.c. Fe,O, 8.3C0 and 20.0 water (3Fe20,.C02+ 12HO). According to Langlois (loc. cit.) the precipitate formed by alkaline carbonates in ferric salts con- tains when dried at 100" C. 81-47 p.c. Fe203 10.17 NO and 1-36CO, which is given off at 165". L. Gmelin (Randb. v. 222) on the contrary states that this precipitate after thorough washing is quite free from carbonic acid. According to Wallace (loc. cit.) the precipitate thrown down by carbonate of ammonia from ferric chloride contains when dried in the air at 22" to 24"C. 3Fe203.C02+6H0 and gives off 2 eq. water at 100";and the precipitate formed by carbonate of soda in a solution of ferric nitrate is 9Fe,03.C0 +l2HO. Mr. Barratt finds that the precipitate dried in the air at ordi- nary temperatures contains 3Fe,0,.C02 +8H0 half of the water being expelled at 100" C.

ISSN:1743-6893    

DOI:10.1039/QJ8611300090

出版商:RSC    

年代:1861

数据来源: RSC