摘要:

Dr. Gregory mi the Prepurntion of Allo.ran. January 5 1846.-The President in the Chair. The Proceedings of the Glasgow Philosophical Society from 1842 to 1845 presented by the Society. The Bakerian Lecture for 1845 by Dr. Daubeny presented by the author. The following papers were read :-Professor Graham described a new eudiometric process for the rapid absorption of oxygen gas from atmospheric air and other gaseous mixtures containing oxygen. It consists in the employ- ment of a solution in ammonia of a sulphite of the suboxide of cop-per and ammonia. This salt falls as a granular powder when a stream of sulphurous acid gas is conveyed into a cold solution of the ammoniacal sulphate of copper. When dissolved in ammonia it absorbs oxygen with singular avidity and when employed in this form in eudiometry gives results of corneiderable uniformity.47 CLIX. On the unequal Decomposition of Electrolytes and tAe Theory of EZcctrolysis. By Mr. JAMESNAPIEII. N a paper which I subriiitted to the Society last session I upon this subjects it was mentioned that the funda- mental law laid down by electro-chemists “That there can be 110 inequality of decomposition in any part of an electro- lyte,” is not applicable under all Circumstances especially when the uegative element of the electrolyte can combine with the positive electrocle there being under such circunistaiices an increased tendency in the electrode to combine with the electrolyte which causes a greater amount of decomposition or chemical action at the positive than at the negative elec- trode.That the extra amount of decomposition at the positive electrode is riot the result of the ordinary solvent powers of the electrolyte for the metal coniposing the electrode was shown by pieces of the same metal being put into the same solutions as the electrolyte the same length of time as the battery was in action and which were in some cases not affected and in others only a small fraction of that which had taken place at the positive electrode above what the current of electricity passiiig accounted for ; showing that the increased affinity between the elements of the electrolyte and the electrode had its origin in some influence communicated by the battery and was not accounted for by the amount of electricity passing measured by the deposition of a nietal upon the negative electrode and as experiments which were being made showed without any relation to that current.I had observed while experimenting upon electrical endos- mose that there seemed some relation between the cause of measurable endosmose and the phaenomenon under considera- tion it became therefore probable that the element of an electrolyte liberated at the negative pole such as a de-posited metal might not be as I had formerly thought an accurate tneasure of the whole electricity passing through the solution under all circumstances but that R feeble cur- rent may be also passing which may be sufficient to give a greater disposition if I may be allowed the term to the solid electrode to combine with the elenients of the electrolyte but not of sufficient power to decompose all the particles of the compound fluid through which it passes to the negative elec- trode the solution conducting it as a solid conductor would or rather as appears from the results described in my paper on * See vol.ii. p. 255. PS Mr. Na pier 011the mrqud DPcmilpositim of E:leciz*olyfes endosmose the electricity taking the tlissolved particles with it to the negative electrode and producing the phmiomena of en(1 osni0se. Th ese siippositions tt1erefore bec a rii e the object of an inquiry which 1 shall now describe in detail. I took a piece of amnlgamated zinc nieasuring 2 by 2:-inches in such state of ainalgamation that dilute sulphuric acid lind no actioii upon it ; this was put into a mixture of sulpliuric acid and water in the proportion of 1 acid to 24 water and surrounded with copper which was placed as close to the zinc as would allow a free current of the solution between them as well as the escape of gas with the view of interrupting as little as possible the free action of the acid upoii tlte zinc.‘This was kept in action for an hour when it was fonnd tht the zinc had dissolved froni it 97 grains. This I assumed as the niax-irrium amount of cliemical action which could be obtained be- tween the zinc and acid of this strength at least under the in-fluence of copper. ‘l’he zinc and copper beiiig again put into this liquill but with the two metals 1 inch apart connected by a slip of copper at the surface of the liquid in one hour there W;LS dissolved from the ziiic 56-5 grains.The two metals being npin placed in the same position but connected by two copper electrodes of equal size placed into a solution of sul-phate of copper at the expiration of an hour there was de-posited upon the negative electrode 9 grains of copper anti there were dissolved fiorti the zinc 10.7 grains. Taking an- other zinc and copper arid putting thern into the acid con-nected with the first in the manner practised for intellsit! there were deposited in me hour 15 grains. The zinc in cell had lost 18 grains. With 4 pairs zinc and copper iii acicl there were deposited 2fi grains aiid dissolved from the zinc 27.7 grains.With G p:urs there were cltyxitetl 34 grains and dissolved from zinc 36 grains ; and with !> pairs there were deposited 43 grains and dissolved froiii the zinc 45 graiiis. And thus it went on increasing in quantity by the addition of plates until the action of the acid and zinc carnie nearly to the same as was assumed as a maximum naniely 97 graiiis ; with 30 pairs there were dissolved horn zinc 101 grains with 35 pairs 99 which I consider very close to the assuined quantity. Assuming the position which the results of these experi- ments suggest I would say that if the chemical energy in-duced between the acid and zinc under the influence ot’ cop-per be equal to 100 grains per hour but by distance or the interposition of a medium of inferior condiicting power the chemical action is reduced to 10 grains per hour the remairi- ing tendency or disposition of the acid and zinc to unite and the Theory of Zlectmlysis.will be equal to 90;and by increasing the action either by adding intensity or decreasing the resistance so that it amounts to 25 grains per hour we decrease the tendency to further action to 75 and so on the one decreasing as the other increases. Now if this tendency for further action be- tween the acid and zinc be the source of this feeble or unde- composing current and this the cause of an extra chemical action at the positive over the negative electrode theo the amount of this extra action at this locality will be greatest- with a weak battery at least have some relation to the surface of zinc exposed and the amount of actual chemical actioti going on.That this is the case the following experiments will show. To save repetition I may state that when smail plates are mentioned the measures of the zinc are 2 by 2; inches; when large plates are named they measlire 5 by 6 inches. 1. With sinall plates the electrodes being the same size as plates both placed in sulphate of copper with a very little free acid. The current passing four hours the results were as under:- One pair negative gained 27 grs. Positive lost 30*5grs. Two pairs ... 44 ... ... 49 a*. Four pairs ... 58 ... ... 63 ... Six pairs ... 70 ... ... 73 ... Nine pairs ... 85 ... ... 87 ... Taking these resrilts in equivalent proportion counting the equivalent of copper 32 the extra action at positive dl be-One pair .......4.1 grains. Two pairs ...... 3.6 ... Four pairs ...... 2.7 ... Six pairs ....... 1*3 ... Nine pairs ...... 0.7 ... The next experiment was with cyanide of potassium in the proportion of 1 oiince to thepint of water. This was put into one division of a decomposition cell the other being charged with sulphate of copper ; silver positive electrodes were used in the cyanide solution. The battery used was of small plates the current passing two hours. One pair negative gained 14 grs. Positive lost 57 grs. Two pairs ... 14 ... ... 50 ... Four pairs ... 20 ... ... 70 ... .I. om* Six pairs ... 21 ... 71 The equivalent of deposit being again taken the proportions of extra solution ofpositive stand thus :-Chem.SOC.Me7rz. VOL. III. E 50 Mr. Napier on the uneqiial Decomposition of EtectroZytes One pair .......9.1 grs. Two pairs ......6-8 ... Four pairs ......5-7 ... Six pairs .......0.9 ... I now took a strong solution of cyanide of potassium and divided it into three equal parts :into two were placed porous vessels filled with sulphate of copper in which were put the negative electrode of the battery one connected with 9 pairs of smallplates the other with 1 pair of large plates. The same sort of electrodes were used in both experiments. The third portion of cyanide of potassium solution had a piece of copper placed in it of the same size with the electrodes.The bat-tery current was continued one hour. The results were- 9 pairs deposited 12 grains dissolved 15 grains ;equivalent 8 grains. 1 pair deposited 4 grains dissolved 7 grains; equivalent 24 grains. Piece of metal in cyanide potassium lost 1.2 grain. Similar experiments were made with various electrolytes in the positive division using sulphate of copper in all cases in the negative the amount deposited being taken as the mea- sure of the decomposing current. 1st. Positive cell charged with a weak solution of cyanide of potassium. 1 pair deposited 7 grains dissolved 10 grains; equivalent propcrtion 13.7 grains. 9 pairs deposited 26 grains dissolved 31 grains; equiva- lent proportion 6-1 grains. 2nd. Muriatic acid 1 to 24 water in positive solution.1 pair deposited 1.5 grains dissolved 23 grains; equivalent 17 grains. $1 pairs deposited 54 grains dissolved 69 grains; equiva- lent 8.8 grains. 3rd. Positive solution nitric acid I to 24 water. I pair deposited 17 grains dissolved 20 pins ;equivalent 5.6 grains. 0 pairs deposited 26 grains dissolved 29 grains; equiva- lent 3.7 grains. 4th. Positive solution sulphuric acid 1 to 24 water. 1 pair deposited 20 grains dissolved 23 grains; equivalent 4.3 grains. 9 pairs deposited 49 grains dissolved 55 grains ;equiva-lent 3-9grains. The next series of experiments are of the same kind using and the Theor-of Electrolysis. I and 2 pairs of large and small plates; but two porous vessels were used put into a vessel charged with the same liquid as the positive the negative in this as in the last being charged with sulphate of copper the electrodes being 2 by Z+ inches in all the experiments 1st.Positive solution sulphuric acid I to 24 water. 1 pair small plates deposited 9 grains dissolved 11 grains ; equivalent 7 grains. 1 pair large plates deposited 9 grains dissolved 12 grains ; equivalent 10-6 grains. 2 pairs small plates deposited 16 gmins dissolved 18 grains ; equivalent 4 grains. 2 pairs large plates dissolved 19 grains dissolved 22 grains ; equivalent 5 grains. 2nd. Positive solution muriatic acid 1 to 24 water. 1 pair small plates deposited 5 grains dissolved 6 grains; equivalent 6*3grains. i pair large plates deposited 7 grains dissolved 9 grains; equivalent 9-1 grains.CL! pairs small plates deposited 9 grains dissolved 12 grains ; equivalent 9.4 grains. 2 pairs large plates deposited 1 1 grains dissolved 16 grains ; equivalent 14.5 grains. 3rd. Positive solution nitric acid 1 to 24 water. 1 pair small plates deposited 8 grains dissolved 9 grains; equivalent 4 grains. 1 pair large plates deposited 8 grains dissolved 10 grains ; equivalent 8 grains. 2 pairs small plates deposited 14 grains dissolved 15 grains ; equivalent 2.3 grains. ~t pairs large plates deposited 19 grains dissolved 21 grains ; equivalent 3.3 grains. I now took three separate pairs of small plates excited by 1 sulphuric acid to 24 water and to each attached copper electrodes which were placed in a solution of sulphate of copper the electrodes of one were one-half size of the battery plates of the other equal size and of the third twice the size of the battery plates.The current passed sixteen hours the results were as follows :-Small ne,dve electrode gained 25.4 grains positive lost 293 grains ; equivalent 4.9 grains. Equal-sized negative electrode gained 33 grains positive lost 37 grains ; equivalent 3.8 grains. E2 52 hlr. Napier on the uizequal Ilecomnpositiorz of Electrolgtes Large negative electrode gained PZ grains positive lost 44 grains ; equivalent 1.5 grain. A piece of zinc and copper each measuring 3 inches by 3 were placed in distilled water and two small electrodes 1 by 2 inches attached and placed in a solution of sulphate of copper.The current passing was sufficient to deflect a delicate galva- nometer needle 3' the current was allowed to pass seventy- two hours. The electrodes being asgain weighed the negative had undergone no change the positive. had lost 2.6 grains. Another experiment of the same kind but the electrodes placed in dilute sulphuric acid 1 to 100 water the current passed forty-eight hours ; the negative electrode was found unchanged the positive had lost 2 grains. A piece of copper suspended in the acid solution during the same time remained unchanged. These experiments which are only a few of a great many that were made,all bearing more or less on the point 1 think sufficiently prove the view taken both of the origin of the undecomposing current of electricity and also that it is that current which produces the pha~.noinenon under discussion ; namely a disposition in the positive electrode and in the zinc in the hattery to combine with the negative element of the electrolyte up to a given point varying according to the strength of acid arid the negative properties if we may so term it of the metal in contact with the zinc througli the in- fluence of which the cliemical action is induced.The results of the experiments of this as well as my pre- ceding paper upon electrical endosmose are applicable to the explanation of various natural and chemical phaenomena the investigations into some of which I am at present engaged with. At present I shall confine myself to a few remarks upon the philosophy of electrolytic action which these experiments suggest .The manner in which electricity passes through and decom- poses solutions is a subject that has occupied the attention of electro-chemists since its power to do so was first known and the opinions published are almost as numerous as the inves- tigators; the greater part of which having been already col- lected and published by Professor Faraday in his Fifth Series of Researches need not be repeated here. Suffice it to say that the whole of these theories being based upon the suppo- sition that there is a mutual transfer of both the negative and positive elements of an electrolyte and that supposition being now found incorrect these theories cease to be tenable.From the first time that I observed that the baseof an elec- trolyte was not transferred my mind becanie impressed with and the Theory of Elecbolysis. atheory of electrolytic action which seemed to agree with the results of my every-day experience in electro-metallurgy and also with various experiments made on a small scale in order to test these views more fully. During these trials I was favoured with a copy of the paper of the late Professor Da-niell and Professor Miller on the decomposition of secondary compounds in which the non-transfer of the basic element is observed but the statement made at the same time that this is not universal some elements such as potassium sodium &c. being transferred in certain proportions.These state- ments interfering with my views induced me to investigate the subject more closely. The paper now snbmitted to the Society forms a portion of these investigations the results of which induces me to think it probable that the results ob-tained by these gentlemen were due to what I term unrnea- surable endosmose rather than to electrolytic transfer ; arid that no basic elenient of an electrolyte is ever transferred by electrolytic action but that the base of ail electrolyte which is being decomposed is the medium or conductor of the elec- tricity through the solution from electrode to electrode. And the manner in which this takes place I conceive to be as f'o1lows :-2 n C' 52 1 The double row represents a line of cotnpound atoms form-ing an electrolyte n the acid or negative element ofthe elec- trolyte b the base or positive elenient of the electrolyte cc the wires or solid conductors of the electricity from the battery to the decomposition cell; the last particles in contact with the electrolyte may be viewed as the electrodes.The a b particles are held together by their affinity for each other. Now let it be supposed that an equivalent of electricity leaves the positive terminal of the battery and passes along the solid particles of the conductor that particle upon which the electricity rests must be for the time in a higher state of ex-citement than the other particles. When the electric current conies to the last particle ot' the solid chain which is in contact 54 Dr.Ylayfair on a convenient with the electrolFte its increased excitement causes it to at-tract and coni\)ine with the acid particle nearest it a 1 ;when these unite the electricity passes to the first basic particle b 1 giving it an exalted excitement which causes it to unite with the acid particle a 2 the electric force passing to b 2 which becomes excited in turn and takes the particle a 3 ;and so on through the chain till the last particle b 5 which having no further acid to combine with gives its electricity to the solid conductor which passes along to the battery. If the last particle b 5 be a metal that can exist under the circum- stances in which it is left such as copper silver &c. it ac-cumulates upon that electrode as a deposit; if not such as can exist under these circumstances such as potassium &c.it decomposes water and hydrogen is evolved By this we observe that every equivalent of decomposition will carry an equivalent of acid to the positive electrode. This is exactly what is touiid by experiment to be the case. That these de- compositions and combinations amongst the particles of a salt may produce a current of that salt in the direction of the electric current producing endosmose can very easily be coil- ceived . Whether this be the true philosophy of electrolytic action is yet to be further investigated; in the mean time it does not appear iriconsistent with any experiments I have yet investi- gated but should it be foulid not to account for electrolytic action under all circumstances it will be gratifying should it only prove a stepping-stone to a clearer view of the subtile action of this power.It appears to me that the phaenomeiia observed and de-scribed in these papers favour the idea that electricity is but one power or substance and that that power is identical with chemical affinity. But the further consideration of this point must be deferred till another opportunity.

ISSN:0269-3127    

DOI:10.1039/MP8450300046

出版商:RSC    

年代:1845

数据来源: RSC

摘要:

54 Dr. Ylayfair on a convenieiilt January 19 lS4G.-James Lowe Wheeler Esq. in the Chair. hlr. Button presented specimens of Paraffine Nayhthaline and Anhydrous Phosphoric Acid to the Society’s Museum. The following communication was read :-CLX. OILa coiiveiiienf Itzsti*unzeutfor graduating Glass Tulies. I)K.PLAYFAIR described an instrument for graduating tubes invented by Professor Bunsen of Marburg arid used in the researches 011 the gases from iron furnaces and in the late experiments read to the Society on specific gravity. Instrument for graduating Glass Thbes. It consists of a mahogany board 5+ feet long 7 inches wide three-quarters of an inch thick. Throughout its centre is a groove 1 inch wide half an inch deep arched at bottom for the reception of tubes.At one part 5 inches from the end is placed a brass plate 1; foot long and 2 inches wide in such a position that when screwed down its edge comes one- half over the groove. It is furnished with 4 screw-nuts passing through a cut portion of the plate a quarter of an inch long so as to allow a certain advancement or withdrawal Scale six-tenths of an inch to the foot. C- .I I . - - - - - - 6feet6inches. - - - - - - - - - - -> _H b2 h A D <-Brass 1 foot 9inches.-> of the plate at pleasure. C and 1> are two similar plates placed at the other end of the wooden board C having the same amount of motion as B and being precisely similar in every respect. D is a brass plate of the same dimensions as B and C but the screws go through a hole of the same size as theniselves into the wood.It is cut at iiitervals of five millimetres into notches every alternate one being one-twen- tieth and one-tenth of an inch deep. The instrument is provided with a wooden rod 3 feet long 1 inch broad and half an inch thick E. This is provided with two steel points placed by screws at half an inch from either end. One of these F is in the form of a knife the other G of a bradawl. The instrument is furnished with a screw-driver that these may be removed at pleasure. When a tube is to be graduated it is covered with a thin layer of melted wax and turpentine by means of a camel’s-hair pencil and is placed in the groove between C and D which are then screwed down in their places so as to retail1 the tube firmly in its position.A standard tube previously mathematically divided into niillimetres (the most convenient division) is now placed in the groove under B which is then screwed tipon it ‘rhe rod E is now nsed the pointed steel 011graduatiitg Glrrss Tubes. G being put in one of the millimetre marks on the standard tube; the knife-formed steel F is now upon the waxed tube and is made to make a mark upon it the length of which is regulated by the distance between the edges of C and D. The pointed steel is now removed back one niillirnetre on the standard tube and the correspondirig mark made on the waxed one; and thus we proceed until the whole of the waxed tube is divided into millimetres. The object of the notches is that a longer rnark may be niade at every five millimetres and a still longer one at every ten in order to aid the eye in read- ing.The waxed tube is now removed to a leaden chest containing pounded fluor spar and sulpliuric acid slightly heated which etches it more successfully tlian a solution of hydrofluoric acid. Previously hon-ever to being etched it is desirable to figure the number of millimetres at the space of every ten; and this is coiiveniently done by the steel pointer G after beiiig removed from E. We have thus an accurate measure of length etched upon the tube which should have been one of pretty uniform cali- bre. The next point is to determine the true value of each of the divisional marks. This is done by calibrating it through- out all its length with small portions of mercury say equal in bulk to five grains of water.By this nieans the relative value of each mark may be determined and the proportion which it bears to any given standard. The only possibleerror is in the assumption that the tube is of even cnlibre between the space occupied by the mercury ; but the quantity of this added is so small that any such error becomes quite inappreciable. The convenieiice of this graduator is so great that a long tube may be beautifully divided in the course of a quarter or half an hour. The standard tubes should be made of glass but the original divisions from which this standard is made may be made on wood or any other material.

ISSN:0269-3127    

DOI:10.1039/MP8450300054

出版商:RSC    

年代:1845

数据来源: RSC

摘要:

February 2 1846.-The President in the Chair. Isaac Solly Lister Esq. was elected a Member of the Society. February 16 1846.-Wm. Thomas Brande Esq. Vice-president, in the Chair. Mr. Button presented a specimen of Succinate of Ammonia. Dr. Wilson presented his Essay “ On the employment of Oxygen Gas as a means of Resuscitation in Asphyxia.” Mr. James Napier wab re-elected an Associate Member of the Society. On Atomic Vokunc and Speczjfc Gravity. The following papers were read :-Mr. J. C. Nesbitt described an improved method of detecting alumina. The process depends on the insolubility of the phosphate of alumina in acetic acid and the two following experiments will show the advantages of this test :-1st. Two grs. of alum were dissolved in 1000 grs.of water and a single drop of this solution was mixed with a little solution of phosphate of soda to which acetate of ammonia and acetic acid had been added ; in a few minutes a precipitate of phosphate of alumina was produced. Another drop was mixed with ammonia and the usual tests were employed to detect alumina but no precipitate was produced. Some ordinary solution of potash was mixed with a strong solu- tion of muriate of ammonia. The mixture showed no change after the lapse of two days. Another portion of the same solution of potash was mixed with a solution of muriate of ammonia containing a few drops of solution of phosphate of soda. A precipitate was produced in the course of twenty minutes or half an hour. In order to detect alumina in the ashes of plants or in substances containing similar ingredients it is merely necessary to precipitate the oxide of iron (if any be present) and the alumina as phosphates by the addition if necessary of phosphate of soda acetate of am- monia and acetic acid.This precipitate is to be boiled with a solu-tion of pure caustic potash ; the phosphate of alumina will be dis- solved and may be again precipitated by muriate or acetate of am-monia and acetic acid. CLXI. Researches on Atomic Volume and SpeciJc Gravity. By LYONPLAYFAIR Esq. ESP.,PhB. and J. P. JOULE SERIES11.-On the relation in volumes between simple bodies their oxides and subhurets and on the dzferences exhibited by Polymorphous and Allotropic substances. IN our former memoir we gave a sketch of the progress of discovery in this branch of scientific research but we unintentionally omitted the name of Dumas.Pierre's* in-teresting memoir has clearly shown that twenty years since the French chemist pointed out the fact that isomorphous groups possess the same atomic volume and various chemists amongst whom we have already cited Thomson Kopp, Schroder and Persoz afterwards cultivated the same field. The purpose of our former memoir was to point out that thevolumes of salts are related to each other by simple laws and in the communication which m7e have now the honour to present to the Society it is our object to extend confirm and simplify our views to other solid substances. The correct expression * Millon and Reiset L4riumii~ede C'kemie for 1846.Messrs. Playfair and Joule OR of a law is not generally attained at its first discovery although the truth of the law may be sufficiently indicated In our present memoir we do not treat of substances in solution our object being to confirm the multiple relation which we have already pointed out in the case of solid salts and to exhibit the connexion between the two units 9% and 11-0 which we then assumed as the sub-multiples. We commence with the volumes of the metallic elements which are to a certain extent well-suited for a correct estima- tion of specific gravity. But at the same time it must be borne in mind that the force of cohesion exercises upon them an influence so strong as to make their exact density depend upon the circumstances under which they are examined.Thus iridium possessing after fusion the sp. gr. 20.0 affects only 16.0 when obtained by the reduction of its oxide ;and osmium under similar circumstances possesses respectively the specific gravities 19.50 and 10*0. The effect of hammering certain metals is also well-known to be a means of increasing their density. These points must be kept in view in considering the results obtained by experiment ;for they obviously indicate that the force of cohersion is able to diminish the natural volumes which the metals would otherwise enjoy. In most cases it was unnecessary for us again to determine the density of the metals as that has frequently formed a subject of special examination.But since the more recent dis-coveries in electricity furnish the means of procuring metals in a state of greater purity than formerly we have occasionally availed ourselves of this power in order to obtain results of the most unexceptionable character. In such cases the metal was precipitated upon a platinum wire of known weight and after removing it from the liquid in which precipitation was effected and washing it with distilled water the wire with the adhering metal was plunged into strong alcohol then wrapped in bibulous paper and allowed to remain in a warm place until the smell of alcohol had disappeared. By this means the surface was preserved perfectly clear and untarnished which is not the case in the ordinary modes of drying.The specific gravity was then determined by the usual hydrostatic method care being taken to use recently boiled water for the purpose of removing the air adhering to the metal. The temperature of observation is always understood to be 40'. The specific gravity of the oxides and sulphurets was taken in an instrument similar to that described in our first memoir (page 405) but susceptible of much greater accuracy. In our former instruments as we stated we only measured to the tenths of a grain in those used in our present researches Atomic Volume and Specijic Gravity. we could read off with the greatest facility the hundredth part of a grain. This improvement was effected by using tubes of a smaller bore and graduating them with the instru- ment invented by Professor Bunsen.The capacity of the instrument was determined at 40° the temperature of the maximum density of water and all our estimations in the present memoir refer to this temperature. Turpentine was used as the liquid in the volumenometer and it was restored to precisely the same temperature as at the commencement of the experiment by immersing the instriinient in water. SECTION I. Spec@c Gravities and Volumes of Metallic Elements. Manganese Mn = 27*7.-Bergmann states the sp. gr. of this metal as 6.861 and 7.1. But the later estimations of John and Bachmann being uniform deserve a preference the former gives its sp. gr. as 8.013 the latter as 8*030. The volume of the equivalent is therefore as follows :-Mean.I. Mn volume = 3*46)3,455 11. ... = 3.45 Iron Fe = 28*0.-According to Brisson the specific gravity of this metal is 7.788 according to Karsten 7.790. The volume according to both results is 3.59. Cobalt Co = 29*5.-The specific gravity of this metal has engaged the attention of various chemists and the following results have been obtained :-8*513 Berzelius. 8*558 T. H. Henry*. 8-485Brunner. 8.500 Mitscherlich. 8.538 Hauy. The mean of these results 8'519 gives 3.46 as the atomic volume. Nickel Ni = 29*5.-There are various determinations of the specific gravity of this metal in a fused state. 7.807 Brisson. 8979 Richter. 8.402 Tourte. 8-380Tupputi. 8.637 Brunner. 8*477 Baumgar tner . * Upon a well-fused button weighing 17 1 grains and determined at our request by Mr.Henry. Messrs. Playfair and Joule on The mean result 8.33 gives the volume of the equivalent 3'54. Zinc Zn =32*3.-The following specific gravities are re- corded by Berzelius and Brisson to which we add the result of one of our own experiments on an electrotype specimen of which a detailed account will be found as we proceed. 6.862 Berzelius . 6%1 Brisson. 6*869P. and J. The mean result 6.864 gives 4.71 as the volume of zinc. Cadmium Cd = !%*&-The following specific gravities are the most uniform of those recordedwith regard to this metal :-8*659Herapath. 8*635 Karsten. 8%04 Stromeyer. 8.670 Children. The mean result 8*642,gives the volume 6*46. Copper Cu = 31*60.-our estimations of the specific gravity of this metal agree closely with those of other expe- rimenters 8*83OBerzelius.8*900Herapath. 8.721 Karsten. 8*895 Hatchett. 8*884 P. and J. 8.941 P. and J. The mean of these results 8*862,gives a volume for the equivalent of 3.56. Chromium Cr = 28*0.-Two estimations exist of the spe- cific gravity of this metal. Richter states it to be 5.90 Thom-son makes it 5.1. The mean 5.5 gives as the volume 5-09. Aluminium A1 =13*72.-Wohler has lately given the spe- cific gravity of this metal determined on small quantities as 2-5 and 2-67. Adopting the latter number as most likely to be nearest the truth we have the atomic volume 5.13. Bismuth Bi = 71*O7.-The following estimations are selected as being the most uniform :-9*610Musschenbroek.9*654 Karsten. 9.822 Brisson. 9*831Herapath. 9.882 Thenard. 9*800Leonhard. The mcan result 9*776,yields the volume 7.97. Atomic Volume and Specific Gravity. Tin,Sn =58*90.-The specific gravities recorded by various observers are uniform and agree with the density of a beau-tiful specimen which we prepared by precipitation. 7.291 Kupffer. '7.290 Karsten. 7.291 Brisson. 7.295 Musschenbroek. 728.5 Herapath. 7-248 I?. and J. The mean of these results 7*283 indicates the volume 8.09 for the equivalent of tin. Arsenic As = 75*4.-The specific gravity of this metal seems to vary under certain circumstances as the results obtained by different observers deviate considerably from each other.5.763 Brisson. Stromeyer. 50884 Turner. 5.959 Guibourt. 5-700 Guibourt. 5.672 Herapath. 5*628 Karsten. 5.766 Mohs. The mean 5*767 yields the volume 13.07 j but if we select the two estimations by Karsten and Herapath the mean sp. gr. will be 5.65 and atomic vol. 13.35. Antimony Sb = 129*20.-The following observers have determined the specific gravity of this metal :-6.722 Hatchett. 6-733 Boeckmann. 6*702 Brisson. 6.852 Musschenbroek. 6-860 Bergmann. 6.610 Breithaupt. 6.700 K arsten. 6.646 Mohs. The mean result 6*727 gives the volume of the equivalent 19'21. MoJybdenum Mo = 47*96.-According to Bucholz the specific gravity of this metal is 8*615and 8.636. Hielrn states it at 7500 a number obviously too low.The mean result of the former chemist gives 8*625 as the specific gravity and 5*56 as the volume of the equivalent. Tungsten W = 94%.-D'Elhuyart describes the specific gravity as 17*60; Bucholz as 17.40 ; Allan and Aiken as Messrs. Playfair and Joule 012 17*22. The mean of these results gives 17.40 as the specific gravity of the metal and 5.45 as the volume of the equivalent. Titanium Ti = 24.30.-Wollaston describes the specific gravity as 5.3 Karsten as 5.28. The mean result 5-29 gives the atomic volume as 4.59. Tellurium Te = 64*2.-The following are the recorded specific gravities of this metal :-6*215 Klaproth. 6.138 Magnus. 6.343 Reichenstein. 6*258 Berzelius. 6.130 Berzelius. The mean result 6.196 gives 1036 as the atomic volume.Lead Pb = 103*6.-The specific gravities recorded are as follows ; we also add two estimations by ourselves :-12*2O7 Boeckmann. 11*352 Herapath. 11.352 &%son. 11*330Kupffer. 11*388 Morveau. 11*388 Karsten. 11.445 Musschenbroek. 11.275 P. and J. 11*298I?. and J. The average specific gravity 11-337 gives 9-14 as the atomic volume. Mercury Hg = 101*43.-The specific gravity of solid (frozen) mercury is stated by Kupffer and Cavallo to be about 14-0 which makes the atomic volume 7-24 Silver Ag = IOS.-According to Rrisson the specific gra- vity of this metal is 10.474 according to one of our own experiments 10.522; the mean result 10'498 gives 10.29 as the atomic volume. Gold Au = 199*2.-Brisson describes the specific gravity as 19*258,which gives the atomic volume 10*34.Platinum Pt I98=8.-Brisson states the specific gravity of this metal to be 20.98 a result which is nearly the mean of all the specific gravities recorded. The atomic volume is therefore 497 1. PaZZadiiJm,Pd = 53*3.-Breithaupt describes the specific gravity of a chemically pure specimen as 10'923 a result closely agreeing with the observations of Cloud and Wol-laston. The atomic volume must therefore be 4.88. RAodium R = 52*2.-Cloud took the specific gravity of a Atomic Volume and S'ec@c Gravity. specimen fused by the oxyhydrogen blowpipe and found it to be 11.2. Wollaston states it at 11*0. The mean 11.1 gives the atomic volume 4.7. Osmium 0s = 99*7.-The specific gravity of the metal as obtained by the reduction of its oxide with hydrogen is 10.0; this gives the atomic volume 9.97.Iridium Ir =98*84.-The following are therecorded specific gravitiesof this metal neglecting the determination of Berze-lius which will afterwards come under special consideration. 19*5U Mohs. 18-68 Children 2355 Breithaupt. 22.1 1 Breithaupt. The mean result 20.96 gives 4.71 as the atomic volume. Potassium K = 39*15.-According to Gay-Lussac and Theiiard the specific gravity of this metal is 0-865 ;its atomic volume is therefore 45.26. Sodium Na = 23*3.-Gay-Lussac and Thenard describe the specific gravity of sodium as 0.972. Davy states it at 0.935. The mean 0'953 yields the atomic volume 24.45.Barium Ba = 68*7.-The specific gravity of barium is about 4-0 according to Davy ;hence its atomic volume would be 17-17. Strontium Sr =43*8.-Gehler states the specific gravity to be between 4.0 and 5.0. The mean 4.5 yields the atomic volume 9.73. In the previous part of this paper all the metals are included the specific gravities of which have been determined with any degree of certainty. An inspection of the numbers represent- ing their atomic volumes will show the existence of a decided multiple relation. In our former paper we represented 9.8 the volume of ice as a primitive volume for salts*. This number however must be made up of the numbers representing the volumes of oxygen and hydrogen respectively. The number 9.8 cannot itself represent the primitive volume but a certain sub-multiple of it may do so.A little consideration of the re- sults now detailed shows that this sub-multiple is the number 1.225 or the eighth part of the volume of ice -9% --1925. 8 The divisor 8 is the cube of 2 so that the atom of ice (considered as a globe or cube) will have exactly twice the linear dimen- sions of the atom possessing the volume 1.225. It will however * That number being deduced from the sp. gr. 0'9184 determined by us a number almost identical with that recently found by Brunner 0-918. 64 Messrs . Playfair and Joule on be observed that in several cases the above volumes correspond more exactly to the multiple of a volume of 1.205 -..6125 . 2 But as 1*225 -is rather an exceptional than a general bulk the 2 convenience in illustration of the law of multiple proportions will be considerable.if in the mean time we assume 1*225as the standard number for comparison . We do not state it as the absolute unit. but as a general and convenient standard bulk for illustrating the law of multiple proportions . TABLE 1.-Showing the Atomic Volumes and Specific Gra- vities of the Metallic Elements . Designation . Volume and specific gravity . 1'225 or 1-2. vol . weight . experi-standard theory . 3p . gr..by Sp. gr.by Atomic Vol .hy of ice as iolume b experi-theory . Name. ment . )r cornpa ment . rison. .. Manganese ......... 27.7 3.455 3 3.67 8.021 7.547 Iron.................. 28.0 3-59 3 3.67 7.789 7.629 Cobalt ...............29.5 3.46 3 3.67 8.5 19 8.038 Nickel ............... 29.5 3.54 3 3.67 8.33 8-038 Copper .............. 31.6 3.56 3 3.67 8-862 8-6 10 Aluminium ........ 13.72 5.13 4 4.9 2.67 2.80 Zinc .................. 32.3 4.71 4 4.9 6.864 6.590 Cadmium ........... 55.8 6.46 5 6.12 8.642 9.1 17 Chromium .......... 28.0 5.09 4 4.9 5.500 5.714 Bismuth ............ 71 *07 7-27 6 7.35 9.776 9.669 Tin .................. 58.90 8.09 sg 7-96 7.283 7*400 Arsenic .............. 75.40 13.07 11 13-47 5.767 5.597 Antimony ........... 189.20 19.21 16 19.6 6.727 6.591 Molybdenum ....... 47.96 5-58 44 5.51 8.625 8.704 Tungsten ............ 94.8 5.45 4; 5.5 1 17-40 17.205 Titanium ............ 24.30 4.59 4 4.9 5.29 4.959 Tellurium ...........64.2 10.36 s; 10.4 1 6.1 96 6.167 Lead ................. 103-6 9.1 4 7& 9.18 11.337 11-285 Mercury ............ 101.43 7.24 6 7.35 14.000 13.800 Silver ................ 108.0 1029 84 10.41 10498 10.375 Gold ................. 199.2 1034 8+ 10.41 19.258 19.135 Platinum ............ 98.8 4.71 4 4.9 20.98 20.163 Palladium ........... 53.3 4.813 4 4.9 10. 923 10.877 Rhodium ............ 58.2 4.70 4 4.9 11 el00 10.657 Osmium ............ 99.7 9.97 8 9.8 10.00 10-173 Iridium ............. 98.84 4.71 4 4.9 20.960 20171 Potassium ........... 39.15 45.26 37 45.32 0865 *563 Sodium .............. 23.30 24.45 20 24.50 0.953 -951 Barium .............. 68.70 17-17 14 17.15 4.000 440j Strontilim .......... 43.80 9-73 8 9.8 4-50 4.469 The table exhibits clearly a.simple multiple relation with- Atomic Volume and Specific Gravity. out however giving precise accordance between the theoretical and experimental results in many of the metals* This want of accordance might either be due to the force of cohesion which prevents the metals assuming their natural volumes or it might be owing to the unlike conditions and impurity in the specimens operated upon. To determine these points we in- stituted the following experiments on simple bodies. In order to render our conclusions still more worthy of attention we have repeated the estimation of many specific gravities carefully guarding against any impurity in the sub- stances under. examination as well as any irregularity in their crystalline condition.In the case of the metals no method appeared to us more likely to give unexceptionable results than that of crystallizing them from their solutions by elec- tricity. By this means we have obtained the specific gravity of silver copper zinc lead and tin as follo\vs :-Spec@ gruvity of &lver.-A solution of the cyanide of silver was furnished with two electrodes viz. a plate of silver and a piece of fine silver wire the former being in connexion with the positive the latter with the negative end of a single constant cell of Ilaniell's arrangement. After five or six days we found that the fine silver wire was covered to a considerable thickness with a beautiful crystalline deposit of silver of the most perfect whiteness Having carefully washed the silver we suspended it by an excessively fine platinum wire to the hydrostatic scale of a very excellent balance and weighed it in distilled water of the temperature of 40'.We then care- fully dried it and weighed it in air. Weight in water at 40° . . 84.41 grains Weight in air . . . . . 93.26 ... Sp. gr. reduced to a vacuum 10,537 * In the case of alloys where the cohesion is diminished the results generally are very exact and the coincidence in many cases strikingly iden-ticalwith the theoreticalexpression. Thus Sn Pb has according to Regnault a sp. gr. 8.777 according to Kupffer 8.637 mean 8.707. 221.4 -25'42, 8'707 V being the unit vol. 1'225. Snv x 2 + Pbv =25-10. Sn Pb has according to Regnault sp.gr. 9.387 according to Kupffer 9'436 266.1 -Again St Pb2has according to Kupffer sp. gr. l0*078. -26'40, 10.078 Snv + Pbv x 2 = 26.33. Chern. SOC. Mem. VOL. III. F Messrs. Playfair and Joule on Another similar experiment gave us the following results :-Weight in water at 49O . . 122*93grains Weight in air . . . . . 135*84 ... Sp. gr. reduced to water at 40'. 10'522 I. Sp. gr. of silver 10-537 11. ... 10-522 Mean . . 10*530 Specific gravity of Copper.-A piece of sheet copper was employed as the negative element of a Daniell's cell for three or four days due care being taken to supply the cupreous solution with fresh crystals of sulphate of copper from time to time. The electrotype copper having been detached and washed was then weighed in distilled water at 49'; and then again after drying in air.Weight in water . . . . 149.07 grains Weight in air . . . . . 167.97 ... Sp. gr. reduced. . . . . 8*884 A second experiment conducted in the same way gave- Weight in water . . . . 261.10 grains Weight in air . . . . . 293.97 ... Sp. gr. reduced. . . . . 8*941 In a third experiment we found- Weight in water at 44' . . 264*508grains Weight in air . . . . . 297'838 ... Sp. gr. reduced. . . . . 8.934 I. Sp. gr. of copper 8*584 XI. ... 8-941 111. ... 8.934 Mean . . 8-920 Spec@ gravity of Zinc.-A saturated solution of pure sul-phate of zinc was furnished with electrodes of zinc aiid placed in connexion with a battery consisting of three Daniell's cells.In about twenty-four hours a good plate of tough zinc was deposited on the negative electrode. The plate was weighed in water which had been previously boiled in order to prevent its acting on the zinc. Weight in water . . 181.14 grains Weight in air . . . 212.00 ... Reduced sp. gr. . . 6.869 Atomic Volume und S'ecic Grawity. In a second experiment we obtainecl- Weight in water . . 161.14 grains Weight in air . . . 158.02 ... Reduced sp. gr. . . 6*992 A third experiment gave- Weight in water . . 17605.3grains Weight in air . . . 206*16 ... Reduced sp. gr. . . 6-956 I. sp. gr. of zinc 6.869 11. ... 6.992 111. ... 6-956 Mean . . 6.939 Specgc gravity of Lead.-A very fine platinum wire was made negative (by means of a single constant cell) in a satu-rated solution of acetate of lead ; a plate of lead formed the positive electrode.In about twenty hours a most beautifiil lead-tree was formed 011 the platinum wire The wire with its leaden foliage was then carefully removed from the solu-tion well-washed in hot water and weighed in distilled water at 54O which had been recently boiled to remove carbonic acid gas. The fine platinum wire upon which the lead was deposited served as the means of suspension on the hydro- static scale. Lastly the lead was carefully removed from the water immersed in alcohol wrapped up in bibulous paper and put on a warm stove to dry. By thus operating the lead was dried without losing much of its brilliancy. A very small correction had to be applied for the platinum wire which weighed 0.3 of a grain.Exp. I.-Weight in water at 54' . . 74.74 grains Weight in air . . . . . 62.00 ... Sp. gr reduced to water at 40' and to avacuum . . . . 11*275 Exp. %-Weight in water at 60' . . 62.80 grains Weight in air . . . . . 69.03 ... Sp. gr. reduced . . . . 11.070 Exp. 3.-Weight in water at 54O . . 64.92 grains Weight in air . . . . . 71-22 ... Sp. gr. reduced . . . . . 11*298 Exp 4.-Weight in water at 62' . . 62-82 grains Weight in air . . . . 68-92 ... Sp. gr. reduced . . . . 11.280 F2 Messrs. Playfair und Joule on I. Sp. gr. of lead 11975 11. ... 11.070 111. ... 11*298 IV. ... 11.280 Mean . . 21*231 Specijic gravity of Tin.-The experiments with tin were made in a manner exactly similar to those with lead a solu-tion of chloride of tin being employed.The branching cry- stals of this metal were of extreme beauty. Exp. l.-VCTeight in water . . . 35'74 grains Weight in air . . . . 41.46 ... Reduced sp. gr. . . . 7945 Exp. 2.-Weight in water . . 36*35 grains Weight in air . . . 42-06 ... Reduced sp. gr. . . . 7'363 Exp. 3.-Weight in water . . . 40'58 grains Weight in air . . . 46-99 ... Reduced sp. gr. . . . 7.330 Exp. &-Weight in water . . . 34.063 grains Weight in air . . . . 39477 ... Reduced sp. gr. . . . 7-288 I. Sp. gr. of tin 7.245 II. ... 7-363 111. ... 7*330 IV. ... 7,288 Mean . . 7-306 There are several other metals which we have not yet tried and others as for example iron which we have cot been able to deposit in a satisfactory state; but the instances we have given are we think sufficient to show that the specific gra- vities of the electrotype metals are not widely different from those obtained in the usual way.And therefore while we claim a superior degree of accuracy to our results with the electrotype metals we think that if a law be established for the volumes of the metals it will be indicated with tolerable accuracy by the results obtained in the ordinary way. S'eci$c gravity of Su@hur.-A quantity of flowers of sul-phur was melted in a glass vessel; and after a crust had formed on the surface on cooling the remainder was poured off. The crystals of sulphur weighing 79-07grains were then thrown into a specific gravity bottle partly filled with water.The bottle with its contents was slightly warmed and then boiled under the exhausted receiver of an air-pump in order to remove the air which is so liable to adhere to sulphur. The bottle was then filled up n-ith water reduced to a known Atornic Volume and Spec$c Gravity. temperature and weighed. The weight of the bottle when filled with pure water at 50;’ being 644.22 grains and its weight when filled at the same temperature with water and 79-07 grains of sulphur being 683.97 it follows that 39.32 grains of water were displaced by the sulphur. Weight of water displaced by 79-07 grs. of sulphur = 39.32 grains. Sp. gr. of the crystals 2.010.Specijic gravity of Platinum Sponge.-The experiments with this substance were conducted in exactly the same man- ner as that with sulphur. Exp. 1.-Weight of water displaced by 109*02 grains of platinum sponge ....... =5*15 grains Sp. gr. of the metal ... 21.169 Exp. 2.-Weight of water displaced by 107.32 grains of platinum sponge ....... =5’052 grains Sp. gr. ofthe metal ... 21.243 I. Sp. gr. of platinum sponge 21.169 11. ... 2 1.243 Mean .... 21.206 S’ecijic gravity of Phosphorus.-Weight of water displaced 7 by 44-76 grains of phosphorus =~ 8 grains. Sp. gr. of phosphorus 1-800. TABLE11.-Showing the Volumes of Metals and some other Simple Bodies. Designation. Volume. I-Volume Vol. in-by experi. reased b: Name.$O$ ment. htll. --I___--Silver ............ 108.3 10.285 10-799 9 11.025 10.530 Copper ............ 31-65 3.548 3.725 3 3.675 8.920 Zinc ............... 32.31 4.656 4 889 4 4.900 6.939 Lead ............... 103.73 9.236 9.698 8 9.800 11.231 Tiii ............... 58.92 8.064 8.467 7 8.575 7.306 Sulphur ......... 16.03 7.975 8.373 7 8.575 2.010 Platinum ......... 98.84 4.661 4.894 4 4.900 21.206 Phosphorus ...... 31.44 17.470 18.343 15 18.375 1.800 Iron ............... 28.0 3.590 3.769 3 3.675 7.800 Nickel ............ 29.62 3.420 3.591 3 3.675 8.660 Antimony......... 64.62 9.420 9891 8 9.800 6-860 Solid Mercury .,. 101.43 7.245 7.607 6 7.350 14.000 Gold ............... 99.6 5.107 5.362 49 5.513 19.500 Palladium. ....... 53.36 4-6-10 4.872 4 4-900 11-500 Diamond .........12.00 3.478 3-65I 3 3.675 3.450 Messrs. Playfair and Joule on The volumes given in the above table are evidently in a simple multiple ratio with themselves and by adding one- twentieth they all come nearly into the category of the number 1.225. Whether the contracted state of the metals in the solid state be owing to the attraction of cohesion we have not examined. We think it highly probable however that if the volumes were reduced to the zero of temperature and compared with ice also at the zero they would be found in a strictly correct multiple ratio. The coefficients of dilata-tion which we have examined seem to favour this view as also does the high rate of the expansion of ice found by Brunner; as however we have not yet made many experi- ments on the dilatation of solid bodies by heat we prefer de- ferring the consideration of this point to future communica- tions.Specijk gravity of Metals in a$nely divided state. Under the impression that the contracted state of the metals in their usual solid condition was in agreat measure owing to the attraction of cohesion we now entered with great interest upon the examination of metals obtained by reducing their oxides by hydrogen gas. In these experiments we eniployed a specific gravity bottle on account of the facilities which it presented in the case of those metals which ignite on exposure to air. Specijicgravity of Copperohtained by reducing the Oxide.-A stream of dried hydrogen gas was transmitted through a tube of' German glass heated to redness and containing oxide of copper.After the reduction seemed to be quite completed the opera- tion was carried on a quarter of an hour longer in order to prevent the slightest trace of oxide being left. The tube with its contents having cooled the copper was removed pounded into small fragments weighed and thrown into a specific gravity bottle partly filled with water. This done the bottle with its contents was slightly warmed and then placed under the exhaustedreceiver of an air-pump in order to boil away any air that might possibly lodge among the lumps of metai. The bottle was then filled up with water and placed in a dish of m7ater in order to reduce it to a given temperature.The perforated stopper was then inserted and the bottle dried and weighed. The weight of the bottle when filled with water only being known it was easy to find thequantity of water displaced by the copper in the manner described in the ex- periment with sulphur already cited. Exp. 1.-Weight of water displaced by '712% grains of copper . = 25-22 grains Sp.gr. rediicecl . . . . + 8.428 Atomic Volume and Specijic Grauity. Exp. %-Weight of water displaced by 156*8grains of copper ..lr3*4Sgrains Sp. gr. reduced ..... 8.483 Exp. %-Weight of water displaced by 199*55grains of copper .23-865 grains Sp. gr. reduced ..... 8.360 I. Sp. gr. of copper 8.428 11. ... 8'483 111. 8*360 .I. Mean .. 8'424 Spec@c gravity of Cobalt obtained by reducing the Oxide.-The experiments with this metal were conducted in a similar manner to those with copper except that turpentine was em- ployed in thespecific gravity bottle insteadof water and that the metal was weighed in the tube in which it was obtained and shaken into the bottle with as little exposure to the air as possible.On account of the great expansion of turpentine it was necessary to take particular care in reducing the bottle to a given temperature. The specific gravity of the turpen- tine was found to be 0'8764 at 40'. Exp. 1.-Weight of turpentine displaced by 52.5 grains of cobalt . . 5*57grains Sp. gr. referred to water at 40' 8-260 Exp. S,-Weight of turpentine displaced by 65.26 grains of cobalt . 7.41 grains Sp.gr. referred to water at 40' 7.718 I. Sp. gr. of cobalt 8.260 11. ... 7*m Mean .. 7*989 Spec;@ gravity of Nickel obtained by reducing the Oxide.-The experiments with this metal were conducted precisely as those 6ith cobalt. Exp. 1.-Weight of turpentine displaced by 91-58 grains of nickel . 1O*1 grains Sp. gr. ........ 7.861 Exp. %-Weight of turpentine displaced by 70*28gruins of nickel . 7.81 grains Sp. gr. ........ 7.803 I. Sp. gr. of nickel 7*86l II. ... '7'803 Mean .. 7'833 Messrs. Playfair and Joule 072 Specijic gravity of Iron obtuined by reducing the Peroxide. Weight of turpentine displaced by 46*7 grains of iron ........ 7-52grains Sp. gr. ........... 7.130 Spec@ gravity qf Arsenic obtairwd from Arsenietted Hy-drogen at a low temperature.Weight of turpentine displaced by 1.031 grains of arsenic .......0.1 71 grains Sp. gr. ...........5.230 Specij2gravity of Flowers of Sulphur.-The sulphur having been thrown into a specific gravity bottle a small portion of water was added to it and the bottle well-shaken so as to cause the sulphur to be thoroughly wetted. The bottle was then placed under the exhausted receiver of an air-pump so as to remove the air lodging in the sulphur. Then more water was added and the same operation repeated. When at Inst we were satisfied that the sulphur was entirely deprived of air we filled the remainder of the bottle with water reduced it to a known temperature and weighed it. Exp. 1.-Weight of water displaced by 15Sa2grains of sulphur..82*82grains Sp. gr. reduced to water at 40' 1*910 Exp. 2.-Weight of water displaced by 167.12 grains of sulphur .87'22 grains Sp. gr. reduced ..... 1*916 I. Sp. gr. of flowers of sulphur 1*910 XI. ... ... 1.916 Mean ..1.913 Specijic gravity of Platinum obtained by exposing the Oxide to a bright red heat. Weight of water displaced by 111*92 grains of platinum ...... 6.3 grains sp. gr. ...........17-766 This does not differ much from the specific gravity 17*890 of the same body as obtained by Scholz. Spec@ gravity qf Uranium obtained by Wohler's method. Weight of turpeiitine displaced by 65.475 grains of uranium ......6.74 grains Sp. gr. ...........8.425 Atomic Volume and Spec.l;;f;cGravity.73 Specific gravity of Magnesium.-The specimen examined was prepared and presented to one of us by Professor Liebig. Exp. 1.-Weight of turpentine dis-placed by5.235 grains of magnesium:. .... PO33 grains Sp. gr. ........ 2.233 Exp. 2.-Weight of turpentine dis-placed by 4-144grains of magnesium ..... 1*60 grains sp. gr. ........ 2-246 I. Sp. gr. of magnesium 2.233 11. ... 2.246 Mean 2.240 TABLE111.-Showing the Volumes of several Metals in a finely divided state and that of Flowers of Sulphur*. Copper ............1 Iron ...............1I Cobalt............... l Nickel.. ............. I1 Designation. 31.65 . 27.18 29-57 29.62 II 3.757 3.812 3.701 3.782 1'225 as unity. 3 3 3 3 Volume. 1 theory. 1 theory. Volume by Sp.gr. by 3.675 3.675 3.675 3.675 8.6 12 8.047 8.060 7.396 SP. @..byexpen-ment. 8.424 7.989 7.832 7.130 Arsenic ............I Sulphur ............ Platiniurn ......... 37.67 16.03 98-84 7.203 8.380 5.563 6 7 43 7.350 8.575 5.512 5.125 I -870 1 7.93 1 5.230 1.913 17.766 Uranium............ 217.26 25.790 21 25.725 8.445 $425 Magnesium ......... 12-69 5.665 43 5.512 2.302 2.240 The results above tabulated are we think sufficient to render it evident that the specific volumes of the metals in a perfectly divided state are strict multiples of the volume 1.225. Speci$c gravity of Melted &?eta~s. We now sought an additional confirmation of our views in the volumes of metals in the melted state. And as no doubt could be entertained that this condition n-ould completely obviate the influence of cohesion or that of any particular arrangement of particles we felt that a complete confirmation * The volumes of metals in this table are not always the same as those in Table I.; the reasons of the difference will be given in a future part of this memoir. Messrs. Playfair and Joule on or refutation of all the views we have advanced would depend upon the results arrived at with the fiised metals. The in- strument we employed when the metals could be fused at a low temperature consisted simply of a small glass matrass (see Figure) formed by blowing a bulb at one end of a tube of about a quarter of an inch diameter. The content of the bulb was ascertained by finding the weight of mercury which could fill it up to a given point of the stem say x.A quantity of mercury equivalent in volume to five grains of water was then added and another mark made at y. This done the matrass was filled with small pieces of the metal under examination and carefully exposed to heat. As the metal melted additional portions were introduced un- til the liquid metal stood somewhere between the marks x and y the exact position being determined to within one-tenth of the space. The whole having then been allowed to cool the matrass was broken and the metal weighed. Specijic gravity of melted Lead. Exp. 1.-Capacity of matrass in grs. of water at 40° 124.17 Capacity corrected for expansion of glass 125.18 Weight of the lead ........1316grs. Sp. gr. of the melted metal .....10.513 Bxp.2.-Capacity of the matrass ...6497 Capacity corrected for expansion 64-90 Weight of the lead .....678-2 grains Sp. gr. of melted metal ...10-45 Exp. 3.-Capacity of matrass ....43.83 Capacity corrected for expansion 44-20 Weight of lead ......466.9 grains sp. gr. .........10.563 I. Sp. gr. of melted lead 10-513 11. ... ... 10*450 111. ... ... 10.563 Mean ..10*509 Specific gravity of melted Tin. Exp. l.-capacity of matrass . . 116.9 Corrected for expansion .117.57 Weight of tin ....817 grains sp. gr. ...... 6-949 Exp. %-Capacity of matrass ..151'52 Corrected for expansion .152.38 Weight oftin ....1053*5 grains Sp. gr. ...... 6.91.3 Atomic Volume and Spec@ Gravity. Exp. S.-Capacity of matrass .. 133.38 Corrected for expansion . 154-15 Weight of tin . . . 931 grains Sp. gr. . . . . . 6*94 I. Sp. gr. of melted tin 6.949 11. ... ... 6*913 IIP. ... ... 6.940 Mean . . 6.934 Spec@ gravity of melted Bismuth. Exp. 1.-Capacity of matrass . . 98-65 Corrected for expansion . 99.28 Weight of bismuth . . 974 grains Sp.gr. . . . . 9*811 Exp. 2.-Capacity of matrass . . 1299 Corrected for expansion . 130 Weight of bismuth . 1268.3 grains Sp. gr. . . . . 9.756 Exp. 3.-Capacity of matrass . . 141*88 Corrected for expansion of glass 14~78 Weight of bismuth . . . . 1414.3 grains Sp. gr. . . . . . . . . 9.905 Exp. 4.-Capacity of matrass . . 103'52 Corrected for expausion . 104.20 Weight of bismuth . . 1013 grains Sp.gr. . . . . . . 9*721 I. Sp. gr. of melted bismuth 9%11 11. ... ... 9.756 111. ... ... 9.905 TV. ..b ... 9.721 Mean . . 9.798 SpeciJic gravity of melted Zinc. Exp. 1.-Capacity of matrass . . 45.8 Corrected for expansion . 46.26 Weight of zinc . . . . 301.*7grains Sp. gr. . . . . . . 6.522 Exp. 2.-Capacity of matrass . . 55.3'7 Corrected for expansion . 55-92 Weight of zinc . . . . 364*1grains Sp. gr. . . . . . . 6.511 Exp. 3.-Capacity of matrass . . 61.84 Corrected for expansion . 62*45 Weight ofziric . . . . 4O6*2grains Sp gr. . . . . . . 6.504 Messrs. Playfair and Joule on I. Sp. gr. of melted zinc 6*522 11. ... ... 6-51 1 111. ... ... 6.504 Mean . 6-512 Specific gravity of melted Potassium.Capacity of matrass . . 95.68 Corrected . . . . . 95.76 Weight of potassium . . 80.7 grains sp. gr. . . . . . . 0-8427 Specific gravity of melted Phosphorus. Corrected capacity of matrass 96 Weight of phosphorus . . 167.3 grains Sp. gr. . . . . . . . 1.744 Specifc gravity of melted Sulphur. Exp. 1.-Capacity of matrass . . 151.03 Corrected for expansion . 15 1.40 Weight of sulphur. . . 273.5 grains Sp. gr. . . . . . . 1.806 Exp. 2.-Capacity of matrass . . 127*84 Corrected for expansion . 128*16 Weight of sulphur. . . 232-1 grains Sp. gr. . . . . . . 1.815 Exp. 3.-Capacity of matrass . . 131.74 Corrected for expansion . 132.07 Weight of sulphur . . . 237*9 grains sp. gr. . . . . . . 1.801 Exp. 4.-Capacity of matrass .. 117.53 Corrected for expansion . 117*80 Weight of sulphur. . . 213-2 grains Sp. gr. . . . . . . 1.809 Exp. 5.-Capacity of matrass . 156.16 Corrected. for expansion . 156.55 Weight of sulphur. . . 282.4 grains Sp. gr. . . . . . . 1.804 I. Sp. gr. of melted sulphur 1.806 11. ... ... 1.815 111. ... ... 1.801 IV. ... ... 1.809 V. ... ... 1-804 Meail . . 1.807 Ck Atomic Volume und Xpecijc Graavity. II Specijic gravity of Sulphur in the viscid melted state. Capacity of matrass ..156.03 Corrected for expansion .156-50 Weight of sulphur. ..273.5 grains Sp. gr. ...... 1.748 Spec@c gravity of melted Antimony.-We found that the temperature at which this metal enters into fusion was too high for even German glass to bear cl-ithout changing figure ; consequently we had now to make a complete change in our manner of operating.We took two capsules of white earth- enware one of which was deep and narrow the .= other wide and shallow. When capsule b was filled with melted metal capsule a was placed upon its top so that its convex surface pressed out part of the metal from capsule b. When all had cooled the ct-eight of the metal was as- b certained and compared with the weight of 6 mercury capable of being held between the capsules. We have estimated the expansion of the capsules at 7;$8th of their bulk for 180° which is the mean of the ex- pansions of brown earthenware and stoneware as given by Dalton *. Exp. 1.-Capacity between capsules .. 45.88 Corrected for their expansion .46*33 Weight of antimony ....308 grains Sp. gr. ........ 6-646 Exp. 2.-Capacity between capsules . 46*01 Corrected for their expansion .46'47 Weight of antimony ....303'4 grains Sp. gr. ........ 6.529 I. Sp. gr. of melted antimony 6.646 11. ... ... 6-529 Mean ..6'587 S'ecijic gravity of melted Copper. Capacity between capsules ..49.97 Corrected for their expansion .50.88 Weight of copper .....370 grains Sp. gr. ........ 7-272 *New System of Chemistry part 1. p. 44. Messrs. Playfair and Joule on Specijic gravity of melted Silver. Exp. 1.-Capacity between capsules . . 55.61 Corrected for their expansion . 56*55 Weight of silver ..... 516.5 grains Sp. gr......... 9.131 Exp. 2.-Capacity between capsules . . 54*62 Corrected for their expansion . 55-54 Weight of silver ..... 515'5 grains sp. gr. ......... 9*281 I. Sp. gr. of melted silver 9*33 1 11. ... ... 9*281 Mean . . 9-206 Spec@ gravity qf fluid Mercury.-The density of this metal at 3YO.2 is 13.588 according to Kupffer. Hence its specific gravity near the point of congelation will be 13*694. TABLE1V.-Showing the Volumes of several Metals and other simple bodies after entering into Fusion. Designation. Volume. I Atomic 'olume. bj 1'225 as 'olunie b 3p. gr. by 3p. gr. by Name. weight. experi-unity. theory. theory. experi-ment. ment. 7.407 6 7.350 13.800 13.694 Tin .................. 58.92 8.497 7 8.575 6.871 6.934 Bismuth ............7I *07 7-254 6 7.350 9.670 9.798 Lead ............... 103.73 9.871 8 9-800 10.584 10-509 Zinc ............... 32.31 4.961 4 4.900 6.5 94 6.512 Antimony ......... 64.62 9.810 8 9.800 6.594 6,587 Silver ............... 108.30 11.764 9' 11.637 9-306 9.206 Copper ............ 31 -65 4.352 33 4.287 7.383 7.272 Potassium ......... 39.30 46-620 38 46550 0.844 0.843 Phosphorus ...... 31-44 18.028 15 18.375 1.711 1.744 8.871 7t 8.831 1.805 1-807 9.170 7; 9.187 1.745 1-748 By ipspecting the above table it v7ill be seen that the atomic volumes of the metals are in general in a simple multiple ratio one to another and are at the same time in a simple ratio with the volume of ice and with the volume 11 given in our former paper. Perhaps the most curious and least ex- pected results are those with copper and silver.These metals appear to assume in the melted state half a volume more than they possess in the solid state. This is highly interesting in the case of copper as it explains the reason why CuO has a volume 3; + 2 instead of 3 + 2. We will not however in- Atomic Volu:me and Specijc Gravity. sist strongly upon this point until we shall have repeated the experiments with copper and silver more frequently and with a more exact apparatus than we have hitherto been able to employ. The specific gravity of sulphur is also very inter- esting on account of the states into which it enters ;of these we have examined five viz.- Sp. gr. Volume. Viscid melted state .....1.748 9.170 Clear amber melted .....1.807 8.871 Flowers ........1.913 8-380 Crystals ........2.010 7'975 Waxy by pouring the viscid sul- phur into water .....la921 8.340 To the relations between the different states of this element we shall have to return. Having now examined three of the conditions in which the metals present themselves we shall conclude the section by recapitulating the principal points at which we think we have arrived. 1st. The metals when obtained in a finely divided state so as to be deprived of cohesion exhibit volumes which are multiple's of the unit 1.225. 2nd. The volumes of metals rendered fluid by heat are in like manner multiples of the volume 1.225. 3rd. The volumes of metals in the solid crystalline condi- tion are in general multiples of a number about ,',th less than 1225.We believe that this may partly arise from the peculiar molecular arrangement but that the contraction is principally occasioned by the operation of the force of cohe- sion. Our first table which gives volumes as we have already observed only approximating to multiples of 1*225 though serving to point out the existence of a law would show a much greater coincidence between the theoretical and actual results than it does at present if we were to apply a sinall correction to the observed volumes as we have done in Table 11. In some instances of Table I. the volume is ~ 1.225 less than 2 it would have been after applying the empirical correction of &th. May u7e not therefore suppose that the contraction occasioned by cohesion is itself in some measure guided by the number 1*225? We think this is not improbable but until we shall have given the subject a more minute investiga- tion it will be premature to insist strongly upon such a view We now proceed to test the law with a class of compounds which do not so readily yield to the solicitation of cohesion.80 iMessrs. Playfair and Joule ot1 SECTION11. Oxides of the Metals. Protoxide of Manganese MnO = 35*7.-The oxide ex- amined was made by passing hydrogen over the hydrate of the protoxide while it was heated to redness. 18-83 grains of the oxide thus prepared gave an increase in the stem of the volumenometer of 3.5 making the sp.gr. 5*38and the atomic volume 6.63. Sesquioxide of Manganese Mn,O = 79*4.-The oxide used in our experiments was prepared by calcining the nitrate. 24*53 grains gave an increase of 5.37 in one experiment and 5-31 in ailother. I. Sp. gr. 4-568 11. ... 4-619 The mean result 4.593 yields the volume 17-29. Our result does not differwidely from that obtained by Leonhard as the sp. gr. of Braunit native sesquioxide viz. 4-85?. Manganoso-Manganic Oxide Mn,O -+ MnO = 115*1,--This common oxide of manganese was obtained by calcining the pure carbonate in open air. 23.13 grains gave arr increase in two experiments of 5.0 and 5.1 respectively. I. sp. gr. 4.746 11. ... 4.653 The mean 4*700 gives the volume 24'49 a result almost identical with that obtained by Leonhard for hausmanite viz.4-72. Peroxide of Manganese MnO = 43*7.-Tiirner has deter- mined the ep. gr. of pyrolusite native peroxide and states it to be 4-81 which makes the atomic volume 9-09. Varvicite Z(Mn0,) + Mn,O + HO = 175*8.-Accorcling to Turner this mineral possesses sp. gr. 4.531 which gives 38% for the atomic volume. Peroxide of Iron Fe,O = 80 ().-The specific gravity of this oxide varies according to the temperature to which it has been exposed. Two specimens heated short of redness gave the following results 24.70 gave an increase of 5.37 and the same quantity in the second experiment gave an increase of 5*19 I. sp. gr. 4-60 11. 4.759 0.. The mean 4.679 gives the atomic volume 17.09. Rut the same oxide raised by means of a wind lamp to a heat Atomic Volume and Speci$c Gavity.approaching whiteness,,gave a different result. 24.70 of the heated oxide gave an increase of only 4.81 making sp. gr. 5.135 and atomic vol. 15*57. Boullay has obviously ex-amined the oxide in this last state for he describes the sp. gr. as 5.225. Magnetic Oxide of Iron Fe,O + FeO = 116.-A specimen artificially prepared by Mercer's method of precipitating boil- ing solutions in atomic proportions of the sulphates of the protoxide and peroxide of iron gave us a sp. gr. of 5.453. The native ore gives similar results. The recorded specific gravities of the magnetic oxide are as follow :-5.400 Boullay. 5045.8 P. and J. 4*908Leonhard. 5.200 Leonhard. 4*960Gerolt.5.094 Mohs. Mean . . 5-168 The mean 5'166 gives the atomic volume 22*44. Protoxide of Cobult COO= 37.5.-19.87 grains gave an increase of 3.55 making the sp. gr. 5.597 and the atomic 170-lume 6'70 ;the same oxide heated to whiteness possessed the sp. gr. 5-75 on operating on 30*13grains. Peroxide of Cobalt Co,O = 83.-This oxide was prepared by heating the nitrate. 24*94grains gave an increase of 50 18 making the sp. gr. 4.814 and the volume 17.24. Herapath describes an oxide of cobalt examined by him as having the sp. gr. 5.322 which would give a volume 15.6 and corre- spond to the strongly ignited peroxide of iron. Protoxide of Nickel NiO =37*5.-39*74 grains increased 7.10 making sp. gr. 5.597 and atomic vol. 6.70. Genth de- scribes the abnormal oxide of nickel discovered by him as having a sp.gr. of 5*745. Peroxide of Nickel Ni,O = 83*0.-The oxide used in our experiments was prepared by calcining the nitrate. 27-33 grains gave an increase of 5.68 making the sp. gr. 4-514 and atomic vol. 17.24 a result closely agreeing with that obtained by Herapath who found the sp. gr. 4.846 and the consequent vol. 17%~ The mean gives 4.830 as the sp. gr. and 17*18 as the atomic vol. Oxide oJ'Zinc ZnO = 40*3.-Boullay describes the sp. gr. as 5-60;Karsten as 5-734 ;and Mohs as 5.432. The mean sp. gr. 5588 gives the atomic volume '721. Suboxide of Copper Cu,O = 71*2O.-l'his oxide was pre-pared according to Bottger's plan by boiling a solution of oxide Chen2. SOC.Men2. VOL. III.G Messrs. Playf'air and Joule on of copper in sugar and potash and was obtained of a beautiful red colour. 20.8 grains gave the increase 3.62 making sp. gr. 5.746. The result obtained by Karsten with the native suboxide 5.751 and that of Leroyer and Dumas 5.75 agree closely with our determination. The mean sp. gr. 5.749 gives 12.38 as the atomic volume. Protoxide of Copper CuO = 39*60.-This oxide was pre- pared by igniting the nitrate avoiding too high a temperature. 22.12 grains gave an increase of 3*75 making sp. gr. 5-90 and atomic volume 6.71. Boullay found the sp. gr. to be 6.13 ; Karsten 6.430; and Herapath 6*401. To ascertain whether the difference of results was due to contraction at a high tem- perature a portion of the same oxide was exposed to a white heat ; 26-69 grains now gave an increase of 4-15 making the sp.gr. 6.414 and the atomic volume 6-17. Oxide of Cadmium CdO = 6Se80.-Karsten states the spe- cific gravity of this oxide at 6.950 which gives 9-18 for the atomic volume. Oxide of Chromium Cr,O = 80'0.-The oxide of chromium occurs in two distinct states commonly Itnomn as the brown and green oxides. The green oxide gave the following result :-24.3 grains gave an increase of 4.95 making sp. gr. 4.909. Wohler found the sp. gr. of the crystallized oxide 5*210. The mean gives sp. gr. 5'059 and atomic volume 15'81. Oxide of Bismuth BiO = 79.07.-26*5 grains of this oxide gave an increase of 3.25 making the sp. gr. 8.079 and the atomic volume 9-79.Karsten found a sp. gr. of 8.173. Oxide of Tin SnO = 65*90.-According to Herapath the specific gravity of this oxide is 6.666 its atomic volume will therefore be 9.8. Peroxide of Tin SnO = 73*9.-Herapath describes the specific gravity of this oxide as 6.640 ;hence its atomic volume will be 11.1. Arsenious Acid AsO = 99*34.-This acid has been fre- quently examined and the following results are those possess- ing the greatest uniformity :-3.702 Karsten 3.695 Guibourt. 3.690 Leonhard. 3-710Leonhard. 3.698 Royer and Dumas. The mean sp. gr. 3.699 yields 26.86 as the atomic volume. Arsenic Acid AsO = 11 5*34.-2953 grains gave in one experiment an increase of 7'34 in another of 7*41 making Atomic Volume and Spec@ Gravity. the sp.gr. respectively 4*023 and 3.985. Karsten states it at 3.734. The mean 3.914 gives the atomic volume 29'47. Oxide of Antimony SbO = 153*28.-2652 grains of this oxide caused an increase of 5*05 making a sp. gr. of 5-251 and a volume of 29-19. Antimonious Acid SbO = 16lm28.-2O37 grains of this compound prepared by igniting antimonic acid gave an in- crease of 5.0 making the sp. gr. 4.074 and atomic volume 39.59. Antimonic Acid SbO = 169*28.-This acid prepared in the usual way by treating the oxide with nitric acid and gently igniting the residue gave the specific gravity 3-77!? and atomic volume 45-06. Oxideof'Molybdenum,MoO =63*9G.-According toBucholz this oxide has a sp. gr. of 5.666 which gives the atomic vo-lume 11.28. Molybdic Acid MOO,= 7lD96.-According to Berzelius the sp.gr. of this acid is 3-49j according to Thomson 3.46. The mean 3475 gives the atomic volume 20.71. Tungstic Oxide WO = 110*8.-According to Karsten this oxide has a sp. gr. 12'11 ; hence its atomic volume will be 9'14. Tungstic Acid WO = 118*8.-It is well known that this acid heightens in colour as the heat to which it has been es- posed is increased. The specific gravity probably differs in the same proportion and this may account for the contra- dictory results given by chemists with respect to its specific gravity. De Luyart states it at 6.12 ;Herapath at 5.274 ;and Karsten at 7.139. The mean result 6-177 gives the atomic volume as 1'3%. Titanic Acid TiO = 40*33.-Titanic acid occurs in various forms to which especial reference will afterwards be made.In the meantime we assume Brookite as the representative of this oxide. The sp. gr. of that mineral 4*128 gives 9.77 as tlie atomic volume. Uranous Oxide UO = 68.-According to Richter this oxide has a sp. gr. of 6'94 making the atomic vol. 9.8. Hydrated Uranic Oxide U,O + HO = 153.-Gmelin de-scribes this oxide as having a sp. gr. of 5*926 making an atomic volume of 25*82. Uranoso- Uranic Oxide UO +U,O,= 21Z.-Karsten states that this oxide enjoys the sp. gr. 7'193 making the atomic volume 29.47. Suboxide of Lead Pb,O = 215*2.-This oxide was made by slowly heating the oxalate to redness. 48-47 grains gave increase 4.96 making sp. gr. 9'772 and atomic vol. 22-02. G2 Messrs.Playfair and Joule on Protoxide of Lead PbO = 111%.-4S*q grains gave an in- crease of 5'24 making sp. gr. 9*250. Herapath states it at 9.277; Karstea at 9.209. The mean result 9'245 gives the volume 12*07. Peroxide of Lead PbO = 119*6.-The oxide experimented upon was made by projecting the protoxide into melted chlorate of potash. 41-46 grains gave an increase of 4.66 making sp. gr 8.897 ;in a second experiment 32.3 grains gave in- crease 3'69 making sp. gr. 8.756. Herapath states the sp. gr. at 8.90. The mean of the three results is 8'851 making the atomic vol. 13.51. Mhium PbO + 2PbO = 342*8,-Herapath describes the specific gravity of this compound as 9*096 ;its atomic volume must therefore be 37.7. Boullay states the sp. gr. at 9.190 a result confirmatory of Herapath's experiment.Suboxide of Nercury Hg,O = 21@8.-Herapath describes the density of this oxide as 10'69 which gives a volume of 19-70. Protoxide of Mercury HgO = 109D8.-56*72 grains of this oxide prepared from the nitrate gave an increase of 5.0 making the sp. gr. 11*344. Berzelius found the sp. gr. 11*074 ; Herapath 11-085 ; Karsten 11.196 ;Boullay 11*000; and Le Royer and Dumas 11-29. The mean sp. gr. 11'164 gives the atomic volume 9-83. Oxide of Silver Ago = 116*O.-Boullay describes the sp. gr. of this oxide as 7.250 ; Herapath as 7.140; and we our- selves found it 7.147 in an experiment with 44.10 grains. The mean of these results 1.179 gives the atomic voiume 16.14. Potash KO = 47*15.-According to Karsten anhydrous potash has a sp.gr. 2.656; its atomic volume is therefore 17.75. S~da,NaO = 31*3.-Karsten describes the sp. gr. of anhy-drous soda as 2*805;hence its atomic volume is 11.1. Barytes BaO = 76-70.-23*86 grains of anhydrous barytes gave an increase of 4'94 and in another experiment 4.785 giving the specific gravity 4.82 9 and4'986 respectively. Karsten states it at 4.733. The mean 4.849 gives an atomic volume 15932. Peroxide of Barium BaO = 84*70.-23*86 grains of this oxide made by passing an excess of oxygen over barytes heated in a porcelain tube,. gave the increase 4.812 making the sp. gr. 4-958 and atomic volume 17.08. Strontia SrO = 51*8O.-Karsten states the specific gravity of anhydrous strontia at 3*932; hence its atomic volume will be 13.3 Atomic Volume and Spec@ Gravity.85 TABLE V.-Showing the Atomic Volumes and Specific Gra-vities of the Metallic Oxides. Specific gravity and atomic volume . 1 Name. Formula. . -... Protoxide of manganese ... MnO 35-7 6.63 5; 6.71 5.380 5.304 Sesquioxideof manganese... MnzO3 79.4 17-29 14 17.1.5 4.593 4.629 Red oxide of manganese ... MnO + Mn203 115.1 24.49 20 24.5 4.700 4.697 Peroxide of mangauese ...... M no 43.7 9.09 73 9*1f 4.810 4.760 Varvicite ..................... 175.8 38.8 32 39.26 4.531 4.484 c Peroxide of iron............... Fe. O3 80.0 17.1 4.679 4.664 strongly heated . 80.0 15.9; 5.135 5.031 Magnetic oxide of iron ...... FeO + Fe.0. I 16.0 22.44 18 82.05 5.168 5.260 Oxide of cobalt ...............coo 37.5 670 5; 6.7 5.597 5.572 Peroxide of cobalt ............ C0.O. 83.0 17.34 14 17.1 4.S14 4.W1 strongly heated ? . Co& 83 0 15.6 13 15.93 5.328 522u Oxide of nickel ............... NiO 37.5 6.70 54 6.75 5.597 5.572 Peroxide of nickel ............ Ni. O. 83.0 17-18 14 17-15 4.830 4.839 Oxide of zinc .................. ZnO 40.3 7.21 6 7.35 5.588 5.489 Siiboxide of copper ......... cu.0 71.2 12-38 I0 12.25 5.749 5.812 Oxide of copper ............... CUO 39 6 6.71 52j 6.73 5.90 5.854 -strongly heated . CUO 39.6 6-17 5 6.12 6.414 6.470 Oxide of cadmium ............ CdO 63.8 9.18 74 9.18 6.950 6950 Water (ice) .................. HO 9.0 9-8 8 9.8 0.918 0918 Oxide of chromium strongly Cr.0. heated........................80.0 15.81 13 15.93 5.059 5031 Oxide of bismuth ............ BiO 790 9.79 8 9.8 8.079 8.068 Oxide of tin .................. SnO 65.9 9-13 8 9.8 6.666 6.666 Peroxide of tin ............... SnO. 73.9 11.1 9 11.02 6.640 6.705 Arsenious acid ............... ASO. 99.3 26.86 28 26-95 3.699 3.680 Arsenic acid .................. AsO. 1 15-38 29.47 21 29.40 3.914 3-923 Oxide of antimony............ SbO. 153.2 29-19 24 29.40 5.251 5.213 Antimonious acid ............ SbO. 161*2t 39.59 33 39 2 4.074 4.114 Antimonic acid ............... SbO. 169.2 45.06 36 44.1 3.779 3.838 Molybdic oxide ............... MOO. 63*9( 11.28 9 11.02 5.666 5.803 Molybdic acid ............... MOO. 71.9 20.71 17 20.82 3.475 3.456 Tungstic oxide ............... WO. 110.8 9.14 74 9.18 2.1 1 12.070 Tungstic acid ..................W03 118.8 19.23 16 19.60 6.177 6061 Titanic acid (brookite) ...... TiO. 40.3; 9.77 8 9.80 4.128 4.115 Uranous oxide ............... uo 68 98 8 98 6.94 . 6.938 Hydrated uranic oxide ...... U.O. + €10 I53 25.82 21 25.72 5.926 5.971 Uranoso-uranic oxide ...... uo + U.O. 112 29.47 24 29.4 7.193 7.210 Suboxide of lead ............ I’h. 0 Z15.2 22-02 18 22-03 9.772 9.759 Protoxide of lead ............ PhO I1 1.6 12.07 10 12.25 9.245 9. 110 Peroxide of lead ............... PbO. 119.6 13-51 11 13-4 7 8.851 8 878 Minium ........................ PbO. + 2 Pbo 342.8 37.7 31 37.97 9.096 0.028 Suboxide of mercury ......... HgjO 5108 19.70 16 19.6 0.69 10.755 Peroxide of mercury ......... 11gO 109.8 9.83 X 9.8 1.1Ci4 11.204 Oxide of silver ............... %: 116.0 16-14 13 15.9 7.295 7.179 Potash ........................47*1! 17-15 17.75 14 2.656 2.749 Soda ........................... Barytes ........................ Peroside of barium ......... Strontia ........................ Magnesia ..................... Lime ........................... I KaO BaO BaO. SrO 3rgo CaO 31.3 76.7( 84*7( 51.8 20.7 B8.5 ll*IOj 17.0s 13.20 6.60 9.13 9 14 11 52 76 11.02 2-805 2.843 15-!)0 4.s49 4.824 17.15 4.958 4.938 13.47 3.939 3.845 6-73 3.135 3.075 9.18 3.12 3.104 __I Messrs. Playfair and Joule on Magnesia MgO = SO*r.-Richter states the sp.gr. of this earth at 3-07; Karsten at 3.20. The mean 3.135 gives 6.60 as the atomic volume. Lime CaO = 28*5.-Royer and Dumas describe the sp. gr. of anhydrous lime as 3.08 ; Karsten states it at 3*16. The mean gives 3.12 as the sp. gr. 9.13 as the atomic vol. In the preceding list of metallic oxides we have given the specific gravity of all those the composition of which has been well-ascertained By tabulating the results we have decisive proof that the number 1.225 or YE5is the primitive 2 volume of the metallic oxides. There can no longer therefore be a doubt that either 1252 or !.?!? forms the sub-multiple for this large class of com-2 pounds. But it is not this fact in its general enunciation that is the principal point of interest in the table for we learn from it at the same time that in most of the oxides 1.225 x 2 forms the combining volume of oxygen.In the class of magnesian metals we find sometimes the volume -1*225,but 2 only when the oxide has not been strongly heated. Are we then to adopt *6125 as the standard volume? We still pre-fkr using for the present 1.225 as the standard for comparison especially as we conceive tlmt the equivalents of the magnesian metals should be doubled. We know various hydrates of the inagnesian oxides and of their salts in which two equivalents of the oxide or salt combine with one equivalent of water. Instances of this are found in hydrated peroxide of manganese, and in Johnston’s sulphate of lime. We know also that we require to use two equivalents of a magnesian oxide to substi- tute one of an oxide of the potash family.From these reasons alone we have almost the right to demand an increase in the equivalents of the magnesian metals. Bnt add to this the simplicity which would ensue were this done and our right to demand the increase becomes much greater. This class of metals favours us with the following series of oxides :-R,O -RO -R,03 -RO,. But the above series besides being unnaturally complex is not complete as it wants the element R30,. It would there- fore be more rational as well as more simple to double the equivalents of the magnesian metals in which case the series would be one of arithmetical progression RO -RO -RO -. RO,. Atomic Volume and Specijc Gravity.Admitting this view the division of 1*225 ceases to be ne- cessary. At present we cannot discuss with propriety the difference of volumes of an oxide before and after being heated but we are prepared to give a satisfactory account of this difference in the latter part of the paper. We must content ourselves at present with pointing out the general facts exhibited by the table under consideration. In the first place we are shown by it that in general the oxygen in the oxides possesses the volume 1'225 x 2. Thus the protoxides of the magnesian metals in their densest state possess the volume 1.225 x 5. We have already seen that the magnesian radical has a vol. 1-225 x 3 ; hence oxygen in the protoxides enjoys two unit volumes.Representing 1*225 by v the following rule prevails for the protoxide :-ROYv x 5 =R v x 3+ 0,v+ 2. The same rule holds generally for all protoxides having the formula ROYthe value of the oxide being the corresponding Rv added to Ov x 2 cadmium and tin being exceptions although in all probability CdO would cease to be an excep- tion if that oxide were examined after strong ignition. The Rv must in all cases be taken in the state when it exhibits itself in its natural power uncontrolled by cohesion. The exception of StO in which 0 is made to possess a unit vol. is obviously connected with the dimorphous relations of the metal. But although 0 in the oxides ROYgenerally pos-sesses two unit volumes it does not do so in all the oxides thus the second equivalent 0 in BaO, SnO, PbO possesses only one unit volume.In the case of Cu,O Xi& Mn,03 &c. it is highly probable that the metal assumes a volume of' v x 4 as in zinc. If so the 0 in these compounds will still enjoy a volume of v x 2. Again if in the case of ice we assume the volume of the 0 to be v x 2 the volume of 1-1 will be v >( 6 which would exactly coincide with the volumes of the other rnagnesian metals if according to what we have already said their equivalents were doubled. There are other points of interest in the Table the consideration of which we defer to another place. SECTION 111. Su&ltureta. Sulyhuret qf Manganese MnS = 43-6.-Thc f'ollowing esti- mations are given of' manganese-glance :- Nfessrs.Playfair and Joule on 3-95 Leonhard. 4-01 Leonhard. 4.014 Mohs. Mean . . 3-991 This makes the atomic volume 10*98. Subsubhuret of Iron Fe,S = 72*1.-This sulphuret was made by passing hydrogen over FeO SO at a red heat. 19.2grains gave an increase of 3*31; hence the sp. gr. is 5-80 and the atomic volume 12.43. Subhuret of Iron FeS =44*1.-A specimen made by holding sulphur in contact with iron at a white heat yielded the following result :-38*3 grains gave an increase of 7.59 making sp. gr. 5.046. Another specimen prepared by fusing iron with sulphur was examined in like manner. 38.3 grains gave an increase of 7.62 making sp. gr. 5*026. The mean re- sult 5.035 gives an atomic volume 8-75. Sespuisutphuret flIron Fe,S = 104*3.-This sulphuret was made bypassing HS over Fe,O,withthe usual precautions.1916 grains gave an increase in one experiment of 3*62 in another 3.53 The mean 3.57 gives the sp. gr. 4'246 and atomic volume 24*56. Bisubhuret of Iron FeS =602.-Karsten describes the sp. gr. of this compound as 4-90 from which we deduce the volume 12%. Subsukhuret of Copper Cu,S = 79.3.-Mohs describes the sp. gr. of copper-glance at 5.695 which makes the atomic volume 13.93. Sulphuret of Copper CuS = 47*7.-Walchner states the sp gr. of this sulphuret at 3.8 ;Karsten at 4.163 ;the mean gives sp. gr. 5.981 and atomic volume 11*98. Subhuret of Zinc ZnS = 48*3,-Karsten has determined the sp. gr. of this sulphuret at 3.925 which gives 12.5 for the atomic volume.Subsutphuret of Nickel Ni,S = 7401 .-This sulphuret was made by passing H over NiO SO at a red heat. 12*1grains gave an increase of 2.0 making sp. gr. 6.05 and atomic vo-lume 12*24. Bisubhuret of Cobalt CoS = 61*7.-This sulphuret made by heating the oxide of cobalt with an excess of sulphur gave the following results. 22% grains gave increase 5.31 in one experiment and 5.37 in another; the mean 5.34 gives sp. gr. 4'269 and atomic volume 14.45. Sesquisui'phuret of Chomiim Cr,S = I 04.-This sulphu-rct was made by passin? dry HS ovc'r Cr,O at an elevated Atomic Volume and Speci$c Gravity. temperature. 16.37 grains gave increase 4.0,making sp. gr. 4.092 and volume 25.41. Sukhuret of Bismuth BiS = 87mO7 .-According to Wehrle the sp.gr. is 7.807; to Herapath 7591; to Karsten 7.000. The mean 7.466 gives the atomic volume 11m66. Subhuret of Cadmium CdS = 71-8-The sp. gr. of Grei-nocket was found by Breithaupt to be 4-90 ;its atomic volume is therefore 14*65. Subhuret of Lead PbS = 119*7.-Karsten found its sp. gr. 7.50; Mohs 7*568;Leonhard 7.40 and 7.60; Brisson 7.587 j and Musschenbroek 7-220. The mean 7*439 gives the atomic volume 16.00. Sespuisulyhuret of Lead Pb,S3 = 255*4.-This sulphuret was prepared by passing HS over Pb,O heated in the water- bath the oxide being prepared as recommended by Winkel- blech by pouring chloride of soda into a solution of oxide of lead in potash. No separation of sulphur took place in the preparation. 16-6 grains gave increase 2'62 giving the sp.gr. 6'335 and atomic volume 40.32. Sukhuret of Platinum PtS = 114*9.-Bottger describes the sp. gr. of this sulphuret as 8-84 making the atomic volume 12.88. Bisukhuret of Platinum PtS = 131*0.-Bottger's deter-mination of 1.224 for the sp. gr. gives a volume of 18.1. Su@huret of Silver,AgS = 124.-Karsten's sp. gr. of 6-85 gives the volume 1891. Sulphuret of Tin SnS = 74*3.-Boullay states the sp. gr. at 5.267 ; Karsten at 4'852. The mean 5.059 gives a volume 14-67. Bisubhuret of Tin SnS = 90-0.-According to Boullay, the sp. gr. is 4-41 5 ; according to Karsten 4.600. The mean 4-50?,gives an atomic volume of 19'97. Sulphuret of Molybdenum MoS = 64.-According to Mohs the sp. gr. of this mineral is 4-59 which gives an atomic volume of 13.9.Sulphuret of Arsenic A@ = 123*7.-This compound has according to Karsten a sp. gr. of 3.459 making the atomic volume 35.7. Sulphuret of Antimony Sb,S = 177*5.-According to Mohs this substance possesses the sp. gr. 4.62 and hence the volume must be 38.4. Messrs. Playfair and Joule on TABLE VI.-Showing the Volumes of certain Sulphurets. Designation. Volumes. ‘olume 3pecific lpecific ‘olume No. of Name. y expe-1’225 by gravity gravity bent. vole. heory. 19expe-by riment. iheory. 43.8 10.98 9 11.02 3.991 3974 Subsulphuret of iron ............Fe,S 72.1 12.43 10 1225 5.80 5.885 Sulphuret of iron ............... FeS 44.1 8-75 7 8-57 5.035 5-145 Sesquisulphuret of iron......... Fe2S3 104-3 24-5 6 20 24.50 4.246 4.257 Bisulphuret of iron ............FeS 602 12.28 10 12-25 4-90 4-914 Subsulphuret of copper.. .......Cu2S 79.3 13.93 11 13.47 5.695 5.887 Sulphuret of copper ............ CuS 47.7 11.98 10 12.25 3.981 3.894 Sulphuret of zinc ............... ZnS 48.3 12.3 10 12-25 3.923 3.943 Subsulphuret of nickel ......... Ni,S 74.10 12-24 10 18.25 6.05 6.050 Bisulphuret of cobalt ......... C0S2 61.7 1445 12 14.70 4-269 4.197 Sesquisulphuret of chromium .Cr,S 104 25-41 21 25-72 4.092 4.044 Sulphuret of bismuth ......... BiS 87-07 11 -66 9.; 11.63 7.466 7.485 Sulphuret of cadmium ......... CdS 7143 14.65 12 14-70 4.90 4.884 Sulphuret nf lead ............... PbS 119.7 16.0 13 15.92 7.479 7.519 Sesquisulphuret of lead.........P$S 255.4 40.3 1 33 40.42 6.335 6.318 Sulphuret of platinum .........PtS 114.9 129 11 13.47 8.84 8.530 Bisulphuret of platinum ...... PtS 131 18.1 15 18.37 7.224 7.131 Sulphuret of silver ............ 43s 124 18.1 15 18-37 6-85 6.750 Sulphuret of tin.................. SnS. 74.3c 14.67 12 14.7 5.059 5-054 Bisulphuret of tin ...............SnS 900 1997 16 1940 4.507 4.597 Sulphuret of molybdenum ... MoS 64 13.9 11+ 14-08 4-59 4.545 Sulphuret of arsenic ............ *4sS 123.7 35.7 29 35.52 3.459 3.482 Sulphuret of antimony ......... SbS3 177.5 38.4 31 37.97 4.62 4.674 The above Table besides affording additional evidence of the law of multiple proportions embraces other points of interest to which we may briefly refer. We have already stated the volume of sulphur to be 7v.Testing therefore the results of the Table by the hypothesis of the sulphur retaining that volume in its combinations we find- 1st. A class of sulphurets in which the volumes of both metal and sulphur remain the same as they are in the uncom- bined state. The following examples of this class are fur-nished by the Table :-Sulphuret of copper . . Cu 3v + S 7v = CuS 10v Sulphuret of cadmium . Cd 5v + S ?v = CdS 12v Sulphuret of platinum . Pt 4v + S 7v = PtS 1lv Sulphiiret of molybdenum Mo 4+v t S 3v = MoS 11;~. 2nd. A class in which the volumes of one or more of the atoms of metal or sulphur disappear whilst the remaining atoms continue to possess the same volumes as when uncomi Atomic Volume and Speci$c Gravity. bined.Of this very remarkablc class we have several. ex-amples viz.- Subsulphuret of iron Fe 3v + FeyOv + S 7v= Fe,S Iov Sulphuret of iron Fey Ov+ S 7v =FeS 7v Sesquisulphuret of iron Fe, 6v + S Ov + S, 14v= Fe,S,,SOv Bisulphuret of iron Fe 3v + S Ov + S 7v =FeS, 1Ov Magnetic iron pyrites Fe, Ov + S, 56v= Fe7S, 56v Subsulphuret of nickel Ni 3v + NI,Ov + S 7v= Ni,S 1Ov Sesquisulphuret of chromium Cr, Ov + S, 21v =Cr,S, 12v 3rd. A class in which the sulphur assumes the volume 6v. In this group we have included the bisulphuret of cobalt in which the volume of the metal is merged. SuIphuret of manganese Mn 3v + S 6v =MnS 9v Sulphuret of zinc . . Zn 4v + S Gv =ZnS 1Ov Sulphuret of silver . . Ag 9v + S Gv =AgS 15v Bisulphuret of cobalt . Co Ov + S,,12v =CoS, 12v There are several compounds included in the Table which do not come under the above heads and the uiicertainty whether their observed volumes are owing to the reduction in the volume of the metal or in that of the sulphur prevents us from advancing anything very positive respecting them.There are however two substances viz. the sulphuret and the sesquisulphuret of lead in xhich Pb evidently assumes a volume of 6v thus-Pb 6v + S 7v = PbS 13v Pb, 1Zv -+ S, 21v = Pb,S, 33v. SECTION IV. Non-metallic Elements and their Oxides and the Oxides of Metals oj unknown specific gravity. Sulphur and Carbon.-For convenience these elements will be discussed in the following section :-Selenium Se = 39*6O.-According to Berzelius the sp.gr. varies from 4-30to 4-32; Boullay found it exactly the mean 4-31 which therefore we adopt as the specific gravity. This makes the atomic volume 9*188. Phosphorus P = 31*44.-The specific gravity of phosphorus is 1.77 according to Berzelius ; this gives the atomic volume 17*76. Boron B = 10*9.-The sp. gr. of this element is generallp Messrs. Playfair and Joule on stated as twice that of water in which case its volume = 5.45. Iodine I = 126*39.-Gay-Lussac and Thenard describe the sp. gr. of this element as 4.948 in which case its atomic volume is 25*54. Taking 2.0 as the sp. gr. of charcoal and 2.010 as that for crystallized sulphur for reasons afterwards to be stated we have the following table of non-metallic elements. TABLEVI1.-Showing the Volumes of certain Non-metallic Elements.I I I I Specific Specific Volume gravity gravity by by expel by riment. 1 theory, I Carbon ......... 1200 6.00 6.12 2.0 1-96 Sulphur ......... 16.03 7.97 7-96 2.010 2.013 Selenium ...... 39-60 9.1 81 9.187 4-31 4.31 Phosphorus ... 31.44 17-76 17-76 1.77 1.770 Boron ............ 10.90 5-45 5.51 2.00 L.978 Iodine............ 126.39 25-54 25.72 4.948 4-914 I In the above Table we have given the volumes of the ele- ments without the reference to the power of cohesion which we made in a former part of the paper. But nevertheless the coincidence between the theoretical and experimental specific gravities is such that we are forced to admit either that the non-metallic elements are entirely free from the influence of cohesion or that as we have before hinted the contraction thus occasioned exhibits itself in submultiples of the volume 1*225 We have now to examine the volumes of certain oxides which were neglected in the previous sections because we were ignorant of the specific gravity of their radicals.Boracic Acid BO = 34*9.-The following estimations are given of the sp. gr. of vitreous boracic acid :-1.83 Berzelius 1*803Davy 1.75 Breithaupt. Mean 1*794 which gives the atomic volume 19-45. Phosphoric Acid PO = 71*44.-This acid in its vitreous state has according to Brisson 2*387sp. gr. and 29*74 atomic volume. Silica,SO = 46*22.-Quartz has a sp. gr. of 2'66 accord- ing to the mean of many determinations.This gives the volume 17*37. Alumina Al,O = 51*4.-The ruby and sapphire possess sp. gr 3.531 equal to an atomic volume of 14.56. Oxide qf T?iorizcm,TliO = 67*6,-The sp. gr. of this oxide Atomic Volume and Specgc Gravity. is 9.402 according to Berzelius ; hence its atomic volume will be 7*19. Glucina G,O = rr.-'I'he sp. gr. of this earth is stated to be 3.0 in which case its volume is 25*66. Yttria YO = 40*2.-Ekeberg found the sp. gr. of this earth 4.842 which gives the volume 8.3. Zirconia,Zr 0 -91*4.-This earth according to Klaproth, has a sp. gr. 433,,,uhich is equivalent to an atomic volume of 21*2. It must be borne in mind that considerable uncertainty exists with regard to the atomic weights of the last four bodies.TABLEVII1.-Showing the Volume of Oxides of Element6 of unkLoown specific gravity. Designation. Volumes. -Volume 1'225 a$ Specific Name. mula. Qtomic iy expe-stan-gravity weight. nment. dard. b For-theory. I -Boracic acid ...... 34.9 19-45 16 19-60 1.794 1.781 Phosphoric acid.. . 71.44 29.74 244 30.01 2.387 2-38 1 Silica ............... 46.22 17.37 14 17.15 2660 2.695 Alumina ............ 51.4 14.56 12 14.70 3-531 3.496 Thoria............... 67.6 7.19 6 7.35 9.402 9.197 Glucina ............ 77 25-66 21 25.72 3*OOO 2.993 Yttria ............... 40.2 8.3 7 8.57 4.842 4-69 1 Zirconia ............ 91.4 21-2 18 22.05 4.300 4.145 SECTION V. Dimorphism and Polymorphism. In Section 11.we pointed out distinct differences in the vo-lumes of oxides before and after being heated and we showed that these differences wereeither 1.225 or 1.225.The ques- 2 tion therefore naturally arose-Is there any such difference between the volumes of bodies of the same composition but of unlike forms ? If any such difference could be established a flood of light would be thrown upon this obscure subject and the alteration in properties would become at once com- prehensible. Let us take some of the most noted examples of polymorphism and dimorphism to test this view. Example I.-carbon offers three very unlike forms and Messrs. Playfair and Joule on conditions the diamond graphite and charcoal. The sp. gr. of diamond varies from 3.4 to 3'5 but as an average may be taken at 3.45.Graphite enjoys a sp. gr. of 25 according to Berzelius* ; Karsten states it at 2.328 the mean gives 2.414. The purest charcoal obtained from alcohol has a sp. gr. of only 2.0. Now assuming from the considerations deduced by Reg-nault from his experiments on specific heat that the equiva- lent of carbon 6.12 should be doubled to 12.24 we have the following simple relations :-Vol. by No. ofvols. Vol. by Sp. gr. by Sp. gr.bg experiment. 1'225 as unity. theory. experiment theory. Alcohol-charcoal 6-00 5 6.12 2.0 1096 Graphite . . 4*97 4 4-90 2.414 2.448 Diamond . . 3.48 3 3-67 3'45 3*27 The result exhibited by this table is very striking as it shows that the three forms of carbon differ from each other by one unit in volume viz. 3 4 5 so that we may conceive the diamond to pass into the graphite by expanding one unit volume and graphite into charcoal by a similar expansion or vice versd by condensation.Ea-ampleII.-tls a second example we may take calc spar and arragonite dimorphous forms of'carbonate of lime of which the following table gives the recorded specific gravities :-Calc spar. Arragonite. 2.718 Brisson. 2995 Breithaupt. 2.931 Mohs. 2'778 -.Baumgartner. 2.946 Beudant. 2.727 i 2.69871 Karsten. AIean . 2-957 2-7064J 2.72.3 Beudant. Mean . 2,725 Calculating the volumes on the equivalent 50'50 we have the following result :-Vol. by 1'225 as Vol. by Sp. gr. by Sp. gr. by experiment. unity. theory. experiment. theory. Calc spar 18% 15 18.37 2*725 2.749 Arrigonite 17-08 14 17-15 2.957 2-945 Thus the same alteration of volume is exhibited here as in the previous example the difference in this case also being one unit volume or 1.225.The experimental and theoretical results are sufficientlynear when calculated on the mean spe-cific gravity but actually accord if we assume that usually * Ann. der Cltemie Bd. xlix. S. 250. Atomic Volume and Specijc Gravity. adopted for calc spar viz. 2.75 according to Neumann and 2.946 for arragonite according to Beudant. Example 111.-A notable instance of dimorphism is exhi-bited in iron pyrites viz. in cubic iron pyrites and in white pyrites or cockscomb spar. According to Karsten cubic iron pyrites has the sp. gr. 4.90 and Mohs states that of cockscomb pyrites to be 4.678.The volume calculated on the atomic weight is as follows :-Vol. by exp. No. of vols. Vol. by theory. Cubic pyrites . . 1298 10 12.25 Cockscomb pyrites . 12.87 10; 12.86 The difference in this case is therefore ~1'225 ; but if our 2 view be correct that the magnesian equivalents should be doubled the number of volumes will be actually 20 for iron py-rites and 21 for cockscomb pyrites making the difference of one unit volume or 1*225,as in the previous cases. Example 1V.-The sulphurets offer examples of unlike forms and allotropic conditions of the same substance. Black sulphuret of mercury has according to our own experiments a sp. gr. of 7.331 whilst according to Musschenbroek and others cinnabar enjoys a sp. gr.of 8.00. The volume calm- lated on the atomic weight 117 is as follows :-Volume by No. of unit Vol. by experiment. vols. theory. RJed sulphuret of mercury 14-6 12 14-7 Black sulphuret of mercury 15*95 13 15.9 The difference in this case also is one unit volume or 1.225. A relation is also shown between the native sesquisulphu- ret of antimony with a sp. gr. of 4*62according to Mohs and of amorphous kermes with sp. gr. 4.15 according to Gmelin. Vol. by exp. No. of unit Vol. by vols. theorv. d 177.5 Native Sb,S, -= 38*42 31; 3859 4 62 Kermes . 177*5 4.15 = 42*77 35 42.87 The difference in this case being 33 volumes. Example V.-The researches of Rose have thrown much light. on the difference in specific gravity between the varieties of titanic acid.Thus we have- 96 Messrs. Playfair and Joule OT~ Artificial TiO sp. gr. 3.66 Rose. f 3.912 Rose. I 3-927 Rose. Anatase . . . . < 3.829 Mohs. 3.759 Breithaupt. 13.826 Mohs. Brookite . . . . 4*128 Rose. Rutil . . . . . 4.256 Rose. These differences are very notable and when calculated on the generally received atom of titanic acid 40'33 viewing it as TiO, we obtain the following relations :-Vol. by exp. No. of vols. Vol. by theory. Artificial TiO 1 1 *O1 9 11.02 Anatase . 10.48 8; 10.41 Brookite . . 9.77 8 9*80 Rutil . . . 9'47 74 9.49 The relations here are very striking but at the same time give rise to new questions. We have previously seen re-1.225 peated exampIes of a volume represented by --,but this 2 is the first instance of -Are t17e to admit the subdivi- 1'225 4.sion of the volume 1*2255! It may be necessary to do so but not on an isolated case like the present. May we not rather suppose that the contraction of volumes takes place on associated atoms ? Thus-1 eq. TiO contracting 1 unit volume forms Brookite. 4 ... ... 1 unit volume ... Rutil. 3 ... ... 5 unit volumes ... Anatase. Which of these hypotheses is right it is impossible to say in the present state of our knowledge; but we do not feel warranted in admitting a further division of 1*225on a single case although we by no means deny that such division may afterwards become necessary especially as far as regards 1.225 2. Example V1.-Quartz and Opul.Silica presents two well-defined forms in qiiartz and anhydrous opal the sp. gr. of the former being 2-66 while the anhydrous opal analysed by Klaproth possesses the sp. gr. 2*072. Atomic Volume and Spec@ Gravily. 1-225 Vol. byexp. a6 unity. Theory. 46.22 Quartz = 17.3 14 17-15 ~ 2.66 46.22 -Opal -22.3 18 22.05 2.0752 The difference in this case is 4v. Exatnple VII.-Alumina forms a similar instance :-1'225 Vol.byexp. as unity. Theory. 'lo4 Ruby . . . --14.56 12 14.70 3.551 51-4 Ignited alumina -= 12.38 10 12.25 4.15 The difference is 1.225 x 9. Numerous other instances of this uniformity of diflerence might be cited if necessary. Example VI II.-E'Zementary allotropism. In the metals we have several well-marked instances of elementary allotropism.Thus Berzelius in his memoir on allotropism has pointed out that iridium artificially prepared has a sp. gr. not exceeding 16.0 while the native metal enjoys a sp. gr. approaching to that of platinum. The most uniform results for native metallic iridium are as follows :-19.5 Mohs. 18*68Children. 22.1 Breithaupt. -__ Mean . . 20.09 98.84 ~ Hence we have for native iridium = 4.92 and for the 20.09 98.84 metal as obtained by reduction -= 6-12. 16.0 Exp. No. of vol. Theory. Native iridium . 4-92 4 4*90 Reduced iridium 6*18 5 6-12 In this case therefore we have the variation of one unit volume between the two different states of the metal. Example 1X.-Osmium presents a similar uniformity in the difference between its three states.Thus according to The- nard wrought osmium has a sp. gr. of 19.5 while that re- duced from the oxide has a sp. gr. of only 10.0 according to Berzelius and when obtained by heating its amalgRm $;*OOO. Chern. SOC.Mem. YOL. III. H Messrs. Playfair and Joule QIZ Exp. No. of vol. Theory. Exarryle X.-Platinum exhibits several very decided allo- tropic differences. Thus in its densest state it has sp. gr. 23.5 (Cloud) ; after fusion the sp. gr. is 20*3(Brisson); the powder obtained by heating the oxide enjoys sp. gr. 17-76 (I?. and J.),while platinum black has sp gr. 16*557(Liebig). Expt. Theory. Platinum black . "*' =5*9716.557 5 6.12 Platinum powder -"" = 5*5617-76 4; 5.52 Platinum after fusion 98.8-= 4-8620.3 4 49 Platinu'rn hammered 23.5 -"** = 4*24 3; 4-28 These numbers and those deduced from the allotropic con- ditions of osmium and iridium offer much confirmation of the view which we are inclined to entertain that the attraction of cohesion is itself' governed by the volume 1*225.Another instance of this contraction is seen in palladium which in its usual state possesses sp. gr. 10*923 but when hammered attains sp. gr. 12'14. Exp. Theory. The differences between the theoretical and experimental iirimbcrs are not greater than car1 be accounted for by the uncertain atomic weight. The very numerous instances of a change of volume consequent on the combination of the ele- ments may all be brought to reinforce this part of our argu-ment.For instance in the case of lead uncombined we find r2 volume of 8v but when combined with sulphur a volume of Gv. Nay inore it appears from our former as well as the present paper that the volume of an element is frequently actually uierged. Such ficts lead us to hope for the discovery Atomic Volume and Specijic Gravity. of far more wonderful examples of allotropism than those we have already given. Berzelius has thrown out the suggestion that the presence of the different forms of the radical may account for ailotro- pism in their compounds and our researches go far to prove this sagacious view. We had intended to have devoted our- selves to further proofs of this theory but our memoir has already reached an unreasonable length and we must defer the subject.We have however one other notable instance of allotropism to which we must refer. SULPHUR exists in several distinct states in the first state that of native sulphur we have the following determinations :-risson. 2.033 B' 2.050 Karsten. 1-989 Karsten. 1%98Fontenelle. 2.072 Mohs. 2.027 Osann. 2.066 Marchand and Scheerer. Mean . . 2.019 This result agrees very closely with our own determination 2.010 (see Section I.). The' specitic gravity of waxy sulphur procured by pouring viscid melted sulphur into water is 1959 according to Marchand and Scheerer ; according to our own experiments 1.931 ; the mean being 1.940. The other estimations by our-selves we have described in a previous section and we now find the following relations :-8.57 1.913 The results of the above table afford the most powerful argument for the assumption of a volume ___ that we have 4 yet sccn.niit stillwe adhere to our primitive volume 1.225 believing that a contraction of whole volumes of 1.225 may take place on associated atoms as we alleged in the case of titanic acid. 11 2 '100 Messrs. Playfair and Joule 012 TABLE1X.-Showing the Simple Relation in Volumes be-tween unlike forms of the same body. Designation. Volumes. I -I '225 ' Specific Specific en a! 1 gravity gravity bY Name. kin-theory. 'by 'Y ard. iment. theory. 5 6.12 2-0 2.0 c2 4 3 4.90 3.67 2.5 3.5 2.5 3.33 so CO,' 15 14 8.37 7.15 2.725 2.957 2.749 2.945 FeS 10 10; 2-86 8.25 4.678 4-90 4.664 4.897 13 5.90 7.331 7.358 HgS Sb2S3 12 35 31+ 4.7 1287 18.59 8.001 4.15 4-62 7.959 4.140 4.600 9 11.02 3.66 3-659 TiO 8+ 8 10.41 9-8 3-85 4.128 3.874 4.115 SiO 7% 18 14 949 22.05 17-15 4-256 2.072 2.660 4.249 2.096 2.695 A1903 12 10 14.70 12.25 3.531 4-150 3.496 4.195 Jr 5 4 6.12 4.90 16.0 20.09 16.15 20.17 12 14.70 7.0 6.721 0s 8 9.8 10.0 10.20 4 4-9 19.5 20.40 5 6.1 2 16.557 16.143 -after fusion ............hammered ............ Pt 4; 4 3; 5.5 1 4.9 4-29 17.760 17.93 1 20.300i20.163 Sulphur in viscid melted state. Sulphur in clear amber melted Sulphur in crystals from fusioi Sulphur in flowers of ............ Sulphur in soft state ........... I S 7 7;7 6; 6 9.1 e 8.8t 8.52 8-23 7.9t 1.807 1.913 1.940 2.010 1.805 1-870 1.938 2.013 Conclusion.We have now to sum up the results of the previous re-searches which we announce generally under the following proposi.tion :-I. The volumes of solid Bodies bear a simple relation to each other being multiples of a sub-multiple of the volume oJ ice ~uhic7~ for convenience is udopted as a standard. a. The force of cohesion in the metals prevents the assump-tion of their natural volumes which however appear when they are placed in a position not to yield to the solicitation of co-hesion. Atov~icVolzme mad Xpecijic Gravity. 101 6. It is probable that the differences from the natural volume produced by cohesion can be expressed by a sub-mul- tiple of the volume of ice.c. The differences between unlike forms of dimorphous polymorphous and allotropic substances are expressed by a sub-multiple of the volume of ice. The results to which we were led by our previous researches now become intelligible. We then asserted that the volumes of salts were multiples of 9.8 or of 11. We guarded ourselves against stating that the latter number was absolutely 11 but we averred it to be ‘‘a number very nearly approaching the number 11.” We now know exactly what that number is and see its relation to 9.8 or the volume of ice-9*8 + 9.8 = 11.025 a number very nearly approaching 11. We have shown in this memoir that 9% is composed of 1*225 x 8 and in the same way 11 is 1.225 x 9. That we should have assumed 11 as the unit volume for salts when we were ignorant of its root.is not surprising considering its frequent occurrence in salts. Thus if Rv be the volume of any radica1,Ov that of oxygen aid Av of an acid the general formula Rv t-Ov + Av =Xv will apply to 11large class of salts divisible by the number 11 although the latter number itself is a multiple of 1.225. The magnesian sulphates have a volume of 22 according to our former paper. By the results in this paper the volume of sulphur in its solid state as flowers of sulphur is 8-57. Oxygen we found in most cases to have a volume of 1.225 x 2; hence SO will be Sv + Ov x 3 = 15*92. The mag- nesian metals were shown to have a volume of 1.225 x 3 hence their oxides as shown also by experiment have a volume = Rv + Ov = 6.12.no . . . . . 6.12 so . . . . . 15*9f2 RO SO . . . 22.04 So that we are conducted by entirely different considerations to the same result which we gave in Table VII. of our former memoir. We stated at Table VI. of that series of researches that KO,SO had a volume of 33*05. By Table V. of the present paper KO is shown to have a voluine of 17-15. SO, we have just shown to have 15-92 Messrs. Playfair and Joule oti KO . . . . . 17-15 so . . . . '15.92 KO,SO . . . w07 a result almost identical with that given and warranting the numbers 11 x 3. We pointed out at the same time that NaO SO differed from this Ian. but the apparent exception is now explained. Our sp. gr. for this salt 2.597 gave the volume 27*5; Karsten's result then referred to 2~331,gave the volume 27-14.Now by Table V.- NaO . . . . 11-025 so . . . . 1592 26'945 The curious class of chrornates find now a complete eluci- dation. Chromium possesses an atomic volume 4.9 (Table I.), while 0 in the acids occasionally has a volume of 4*9,-Crv + -Ov x 3 = 19.6 the exact number which we found by experiment for CrO in our former paper. KO CrO ought to be as follows :-KO . . . 17-15 CrO . . . 19.6 KO,CrO . 36*75 the number which we found being 37.1 a result we then allowed as difficult to be explained. On KO 2Cr0 we find an increase of 1.225 above the second atom of CrQ, due per- haps to the dimorphous relations of chromium. The results as then found and those cakulated according to our advanced knowledge in the present paper are as follow*-Vol.found. Theory. KO CrQ . . . 37.1 36-75 KO ZCrO . . . 57.8 57.57 KO 3Ci-0 . . . 76.8 77-17 Finally let us take the singular results obtained for the carbonates as a test of this view. We found a sp. gr. for KO,CO of 2.103 which is too low a number when com-pared with the only other recorded result that of Gmelin 69.4 -2.264. The latter gives the atomic volume 2.264 -30-65. * We avail ourselves of this opportunity to correct an error into which we fell in our former paper. We there stated that KO 2Cr0 was not reduced to KO Cr03 by litharge but formed a compound 2K0 3Cr0,. By continued action howrvcr the bichromate is wholly reduced to yellow chromate and v-e are therefore satisfied that what we described as 2K0 3Cr03 wns iiierely a iiiisture of KO Cr03 and KO 2C1-0~.Atomic Volunie and 8pec;f;c G'ruvity. Deducting 17.15 for KO we have a volume of 13.5 for CO,. The volume of KO CO + HO CO, according to Gmelin's results and our own was 49.0 from which 3W65 must be de- ducted for KO CO and 4'9 as in the case of many hydrates for combined water. The difference 13.45 is the volume of CO in bicarbonate of potash. Carbonate of soda we found to possess a sp. gr 2.427 which agrees very well with Kars- ten's result 2-465. From the resulting volume 22*0v must be deducted 11v for the volume of soda leaving llv for CO,. NaO,CO + HO CO had a volume of 38'6 from which must be deducted 22-05 + 4-9 for reasons above stated lea- ving 1~65 for CO,.Here then we have- CO in the carbonate of potash = 13.45 co ... ... soda . = 11-65 These differences are therefore connected with the character of the base itself. Are the differences due to the allotropic con- dition of carbon? does CO in the potash salts contain char- coal carbon? and in the soda salts graphit carbon ? does the denser form cause the volume of oxygen itself to become con- densed ? and may we thus explain the differences of calc spar and arragonite ? These are questions which shall be answered in a future memoir. At present the examples above given may suffice for illustra- tions of the accuracy of the standards which we took in our former paper. We reserve for a distinct memoir the import- ant considerations which flow from our present results with regard to the constitution of salts and the behaviour of the water entering into their constitution.It would be easy to give a classification of the metals from the views developed in the preceding sections were it not that their allotropic conditions associate the groups by a distinct chain of connection. We intend to follow up this paper with another in which we shall endeavour to show that the elements not only in their natural states but even in their unusual forms may be Brought under one simple ma- thematical law thus clearly proving that sufficient grounds exist for the acceptance of the law which we have tried to esta- blish in the present memoir,-THAT THE ATOMIC VOLUMES OF BODIES STARTD IX A SIMPLE MULTIPLE RELATION TO EACH OTHER.

ISSN:0269-3127    

DOI:10.1039/MP8450300056

出版商:RSC    

年代:1845

数据来源: RSC

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104 Die. Schaiibein ou tile I@ence exerted by Electrkcify March 2 1846.-The President in the Chair. Mr. Nesbitt presented his Essay “ On the Analysis of the Hop and the Nature of the Manures beneficial to its Growth.” The following papers were read :-CLXII. On the It@mce exerted by Electricity Platinrim and Silver upo?z the Lztniinosity of Phosphor-us. BJ Dr. C. F. SCHCXNBEIN. SOME time ago I tried to show that the shinir;g of phos-phorus in atmospheric air is intirnately connected with the formation of that highly oxidizing agent I have called ozone. The correctness of that view is confirmed by the fact that phosphorus never becomes luminous if‘ the production of ozone be prevented? or that luminous phosphorus grows &Irk it’ the ozone be removed.It is well-known that phosphorus remains (lark at low teniperatures and 1 have ascertained that under these circumstances no ozone is produced ; my experiments have further shown that phosphorus still shines in ozonized air at a teinperature at which in pure air phos- phorus exhibits not the slightest emission of light. According to the results of my former researches ozone is formed during electrical discharges taking place in atmo-spheric air the electrolysis of water and the action exerted by phosphorus upon moist niistiires of oxygen and nitrogeii oxygen and hydrogen ox~gen and carbonic acid gas. 17 lhese facts taken together led me to suspect that phos-phorus might become luminous in atniospheric air within which electrical discliarges had been effected at a temperature at which phosphorus does not she in common air.How far that conjecture is well-founded will appear fi-on1 the fiicts I mi going to state. I. If at a temperature of 9’ to 5O R. below zero it piece of pliosphorus about an inch long arid having a clean surhce be laid upon a wooden board arid the fkee end of’a metallic wire connected at its other end with the ca~iductor of’ail electrical macliine be placed at the distance of a few lines lie-fore the dark phosphorus the latter will become luminous as soon as the electrical brush niakes its appearance at the free end of the wire; arid ili addition 8 ~uii~inoiis tail of 4 to 6 inches long will be perceived behirid the pliospho~w. The brush is no sooner niade to dkappear than the shining tail disappears also w hilst the phosphorus itself rernnins lunii-nous ftJr a second or two niore.The brush being calletl fort11 again the phaenoiiitna described will repeutedly take plnce. Platailurn and Silver on the Luntiiiositj of P'hosphoms. 105 2. l'he same piece of pliosphoriis at a temperature of about /ho R. below zero being. placed within a coil made up ofone extremity of a copper wire so that the end of that coil projects (in the shape of a pint) about a line beyond the phosphorus and the other end of the wire being connected with the conductor of the electrical machine a very interest- ing phaenomenoii will take place as soon as the brush is caused to appear at the metallic point that projects beyond the phosphorus.From the centre of the brush proceeds a luminous cone the apex of which lies in the middle of the brush. The length of that cone varies with the size of the brush the longer the latter the longer the cone. I have often obtained cones at least two feet in length with brushes being hardly an inch long. I am sure the adinirabie machine of the Yolytech n ical Instit utioii would yield tails of extraordinary lengtli anti it is really worth while to make the experiment witti that powerful apparatus. i must not omit to mention that the ptiaenomenon resembles exactly the tail of a comet and cariiiot he perceived but in complete darkness; but it is hardly necessary to add that the luminous cone disappears invariably and simultaneously with the brush.If the finger be approached to the brush so as to change the position of the latter the coiie in its whole length is also put in motion. In the experiments described use was made of the positive brush ; iii changiiig the positive electricity for the negative a tail is likewise obtainec! but that cone is thin and less lively. L..O 3. If at a temperature of R. below zero a piece of phosphorus be placed in rl bottle so arranged that the elec- trical brush may at pleasure be produced within that ves-sel the phosphorus becomes luminous so soon as the brush makes its appearance and that phosphorescence is the more lively the stroriger the brti4i and the ionger the latter had been made to play. 'I'he emission of light continues for a short time to take place after the cessatioii of the play of the l)rush.The phosphorus having grown dark becomes lumi- nous agtliii aloiig with the reappearance of the brush. 4. Accordiiig to my experiments chemical and voltaic ozone are instantaueou4y destroyed by a number of gaseous sub-stances ex. gr. by olefiant gas sulphurous acid fumes of hyponitric acid ~apour of aether kc. Hence it conies that phosphorus placed in atmospheric air mixed up with mall quantities only of any of the substances named does not pro- duce ozone and it is well known that phosphorus remains dark under the same cii*cumstances. If the experiment be made as indicated under $ 3 the electrical brus11 lively as it 106 &'I. Ulex 012 S~ruuite. may happen to play within tlie air of tlie bottle does not call forth in phosphorus the slightest sign of phosphorescence provided the atmospheric air surrounding phosphorus contaiii some olefiant gas hyponitric acid &c.5. Some titne ago I ascertained the fact that either platinum black or spongy platinuni has the power of destroying indigo of colouring blue the resin of guaiacum of decomposing iodide of potassium in short of producing oxidizing effects very similar to those brought about by the electrical brush or spark. r7 1 hat siinilarity of action made me suspect that with regard to phosphorus platinum being in a state of minute mechanical division might conduct itself like electricity and the results of my experiments have proved the correctness of my coiijec-N.below zero newly-prepared ture. 4' temperature of aAt platinum black was placed upon a watch-glass now as sc)on as a piece of phosphoiws (having previously been wiped off with filtering-paper) was niade to touch the metallic powder it became lu~n~noi~s first at the point of contact and inime-diately afterwards along its whole surfkce. On breaking that contact the phosphorus turned dark again. 6. Spongy silver as it is obtained from the acetate of that metal acts upon phosphorus as powerfully as spongy platinum does; for no sooiler has phosphorus been touched by that silver than the former becomes luminous even at a tempera-ture of 6' R. below zero. 7. Iron lead copper antimony bismuth tin being in a state of niiriute mechanical division have no effect upon phos-phorus. With gold iridium and the rest of the nietals I have not yet made any experinlent.

ISSN:0269-3127    

DOI:10.1039/MP8450300104

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年代:1845

数据来源: RSC

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106 C1,XIII. 012Stmvite a HEW Mincml. By G. L. ULEX. UR!EROUS crystals were found in digging out the giounti of St. Nicholas church in the middle of our town ; the largest of which are about one inch long and weigh from 1.4 to 1.8 grni. Their priniary form is a right rhombic prism. [The admeasurements were made by Prof. Marx.] M 011 M . 95' 10' h1 on 0 . . . 132' 25' 0 011 P . . . 138O 25' s 011 s . . . G.3' 30' IL on t . . 143' iionh. * . 5'73 10' M. Ulex 011 Stnivitc. Fig. 3. Fig. 2. Fig. 4. 0 0 ~ R Fig. 7. Fig. S. Fig. 6. -_ I 1I I f 1 I jh ;h\ R h I I I I I I I I I I I I I I II I 0 fGg. 1. Represents a crystal of struvite in its siniplejt form.Fig. 2. The crystal as it most frequently occurs. Fig. 4. A segment. Figs. 5 6. Crystals with some secondary planes but generally only scg- ments occur; the plane s on both sides large and distinct the planes h and t 1ery sniall. Fig 7. il view of the planes collectively as exhibited by some crystals. They cleave parallel to the plane of 0. A peculiarity in these crystals is that they OCCUI' alriivst always in halves and appear to have rested or been formed on planes which would have passed throrigh the centre of the entire crystal. One of these iiatural segnients is shown in fig. 2. r-1lie crystnls are transparent arid ot' a somewhat yellow cofout. niost of them inclose orpnic nintter ::nd are tlret.et)y M.171e.u on Sirmite. rendered more or less dark and opnlte. They are hartler than talc but are scratcliecl \ygypsuni. Their specific gra-vity is 1.7. They are very qiaringly soluble in water and in conse-quence tasteless. Wlioii heated in a tube they give out much water and ammonia (the black crystals empyreumatic water nncl ammonia) without flying into pieces. When heated to redness they exhibit the phaeiioinenori of phosphorescence the passing of c into b phosphoric acid. Heated before the blowpipe they rnelt into a colourless glass which on cooling forms a white enamel. The constituent parts of the salt are phosphoric id mag-nesia ainmotiia and water. Dissolved in liydrochloric acid arid precipitated by am-Inonia they yield a sandy powder which under the micro- scope exhibits the well-known form of the phosphate of :mi-nionin and niagnesia.The salt loses by ignition 54.7to 55.5 per cent. (the cliffer- elice is caused by the sniall quantity of organic matter). The ammonia was estimated by means of tlie chloride of platinum ; by dissolving the salt in hydrochloric acid 6.9 to 7.1 per cent. of :tmmoiiia were found The residue of 44.5 to 45*3per cent. should be the same combination of phosplioric acid with rnag-nesia as is contained in the phosphate of tnagncsia and am-nionia because if the crystals are dissolved in hydrochloric acid and precipitated by ammonia the fluid which is filtered tiom the precipitate give5 no reaction either with sulphate of magnesia or with phosphate of soda.It coi:sists theref’ore of (NH,O) + ZMgO + POj) -!-12HO. The crystals are the same salt wliich is found in many ani- mal secretions and in pitrifyiiig urine. The salt is not altered by the air. Bar. Graliani has in-formed LIS that if’ the artificial salt is heated to 212’ F.it loses 10 at. of water and 110 aninioiiia. The tiiitural crystals cat1 bear R teniperoture of 23.8” F.,and they give out tlie same quantity of water and no aniniotiia The products of distilla-tion were condiIctetl itito a solution of the nitrate of the pro-toxide of mercury which was iiot lilackened. Concerning tlie locality where the crystals are found we perceive below the upper strata at a depth of‘6 to 12 feet a large quantity of cattle-clung mixed with straw in a state of putrefaction.This passes hy degrees into a black peat earth which extends to a depth of 26 feet and rests upon gravel. r’l I lie peat earth of’ it tIiicki?ess ot’ 10 to 12 feet consists of a homogeneous inipa!pat)le Iiinss inixetl liere and there with M. Ulex on Slruvite. small parts of vegetable remains (parts of grasses ; Sphagnum aiitl other mosses could not be detected). This is the true matrix of the crystals in which here and there blue iron earth (protophosphate of iron or vivianite) is also found. I3y drying in the air it loses /40-50per cent. of water and is iiot to be distinguished from the he.ivy black turf. Water dissolves very little from it. The solution is of a light brown colour without any reaction upon litmus.Heated it gives off at first soine ammonia; in other respects it smells aid burns like turf with a bright flame. The ashes which remain vary in weight from 20-30 per cent.; nioistened with water it does not act iipn litmus. A quantity dried at 212' F. was subjected to analysis; 100 parts of it gave-2-0per cent. soluble in aether (principally chlorophylle). 1.5 ... . . . alcohol (principally resinous matter). 1.5 ... ... water (principally salts of humous acids). ... liquor potassae (principally humous acids). 36'0 ... organic residue (principally huniine and vege-table fihrine). 23'0 ... inorganic residue consisting of-0.3 ... soluble in water (sulphate of potass and chlo- ride of sodium 110 phosphates of alkali).11.5 ... soluble in hydrochloric acid (principally alu-mina and phosphate of magnesia and lime less peroxide of iron and sulphate of lime). 12-2 ... insoluble in hydrochloric acid (sand ; calcined with sotla and decomposed by hydrochloric acid it gave 11 silica 1.2 aluinina and per- oxide of' iron). The analysis shows that we have a hiimous mass which has been fornied from organic matters by putrefactioii and decay. It is probable that these matters were principally the excre-tjleilts of Ijerbivorii ;a pi*esun~ption which is supported by the aiidysis of the ashes from the quantities of phosphate of rnag-iiesia and lime. The solid excrements of the Herbivora are characterized by abundance of phosphate of rnapesia arid the deficiency ofarnmoniacal salts ;the fluid excrements (urine) have on the contrary abundance of' ammoniacal salts (froin the decompo- sition of urea) aiid are deficient in earthy salts; relations which make it probable that the formation of such large cry- stals in such quantities (they occur in thousands) was caused 110 M.Ulex on SImvite. by n reactioii of the urine upon the solid excrements where the first give the ninmonirt the latter the phosphate of mag-iiesia. The locality where the crystals are found confirms this as- sumption. The place where St. Nicholas’s ctiurcli is built wm occupied 800 years ago by the New Castle (New Burg) which was burnt and dejtroyed with the whole city of Ham-biirg iu 1072 by Kruko tyrant of the Wenden. Now it is most probable that the ditch of the cn,tle was used as a reser-voir for rubbish and manure by the inhabitants of the new- built city who preferred trade as more profitable to agri- culture.So by degrees the ditch was filled and covered partly with houses and n small part of it formed till a late period an operi dting-pit which was emptied from time to time. The crystals are found principally below the dung-pit arid appear to be formed by the infiltration of urine through :i soil consisting of vegetable matters. The crystals forming a mineral which has never yet been described are nnrried Struvite in honour of the minister Von Struve well known to mineralogists and highly meritorious from the great interest he takes in the advancement of science in the town of Hamburg.

ISSN:0269-3127    

DOI:10.1039/MP8450300106

出版商:RSC    

年代:1845

数据来源: RSC

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110 Rfiirch 16 1346,-The President in the Chair. Mi-. Robert Porrett presented to the Museum a specimen of Sul-phocyanide of Copper prepared by him in 1816. hIr. Thomcxs ‘l’aylor presented a copy of his papers “On some New Species of Animal Concretions,” and “ On some New Species of Biliary and Intestinal Concretions.” Chnrles Oakes Esq. and Thomas Taylor Esq. were elected Members. The following papers were read :-6‘€<eeply to the Observations of $1. Pierre on the Proportion of Water in the Magnesian Sulphatcs and Double Sulphates,” by ‘I’homas Graham Esq. Mr. Warren De la Rue described a new body which he had ob-tained from cochineal a subject he lias been for some time past invcstigating and which bears a remarkable similarity to a substance which Liebig has lately produced by the action of potassa on caseine to which he assigns the composition C,6,N H, Oi at the same time stating that the formula requires confirmation.Though the analyses of the new substance differ somewhat from this formula (its compo- <ition appearing to be C,s N HI, 0,) yet the agreement of its 1)ropeities with those assigned by Liebig to the substance described by him lenres but little doubt as to the identity of the two bodies. Drs. NIuspratt and Hofrnann OTL ivitrnniline. 11 1 A specimen of Liebig’s substance furnished by Dr. Hofmann agrees perfectly in its physical characters. ‘l’lie new body is obtained from cochineal by the following nicnns :-The colouring principle being first separated from an in- fusion of cochineal the mother-liquor is to be carefully evaporated in il water-bath to the consistence of a syrup when there appears floating in it a small quantity of granular chalky-like masses which king collected on a filter is kept warm and when drained well- wnshed with cold water ; they are then dissolved in boiling water and recrystallized ; again well-washed and finally dissolved in as mall a quantity of boiling water as possible ; a little animal char- coal is to be added and the ehullition continued for a short time ; on filtration and cooling the new body crystallizes as a bulky assem- blage of tufts filling the vessels ; on drying they form into paper- like masses of a perfectly white colour and a beautiful silky lustre.This body is sparingly soluble in cold water considerably more so in hot water ; solubIe in ammonia from which it crystallizes as the ammonia is driven off by heat; it is likewise soluble in acids.From the process pursued in separating this substance from cochi- neal there is nu doubt that it pre-exists and is not produced by the operation ; it may however be a product of oxidation of some part uf the insect during its preparation for commerce. Three hundred 1)artsof cochineal yield one part of the new body. CLXIV. On Nitraniline a new Prodt~ctof Decomposition of Dinitrohenxol. By JAMESSHERIDAN MUSPRATT P1t.D. and AUGUSTUS HOPMANN, WILLIAM Ph.D. 4 GREAT number of investigations have proved that the A action of nitric acid upon organic bodies produces changes in their composition in two ways.First there is sometimes simply an accession of oxygen to the elements of the organic matter the nitric acid being reduced to nitric oxide or riitrous acid and expelled. Thus by treating indigo with nitric acid it becomes converted into isatine the compo-sition of which difFers from that of indigo only by containing tw equivalents of’ oxygen more than the latter. Cinnamic acid passes into hydride of benzoylc water being f’ormed and thc excess of carbon combining with the oxygen of the nitric acid escapes in the form of carbonic acid. By a further supply of oxygen the hydride of bcnzoyle is converted into Ben,zoic acid. In all other cases the action of nitric acitl ditkrs in no respects from that of other means of oxidation cx.yr. chromic acid peroxide of manganese and sulphuric acid &c. The action of nitric acid Eiowever upon organic matters is ill other cases more complex; it does not consist solely iri the ~ipplyof’ oxygen but besides that element nitrogen dso 113 Drs. Muspratt and Tlofmann on Nitraniline enters into the newly-formed compound. I76dig0 subjected for a long time to the action of concentrated nitric acid under- goes a series of metamorphoses and the last product which is formed namely cnrbaxotic acid (nitrophenisic acid) con- tains to the smie quantity of carbon a much larger propor- tion of nitrogen than the indigo fiom n-hich it is derived. Cinnanzic acid hgdride of benzoyk and bewoic mid none of which contain nitrogen furnish as the last product of the action of nitric acid a nitrogenous acid which is known as nitrobenzoic (nitrobewinic) acid.A great many of the nitrogenous compounds produced in this manlier possess the properties of acids. Besides the above-mentioned we might enumerate nitrocinnamic acid nitrosali- cyZic acid (anilic acid) and many others similarly constituted. Some chemists have on this account without hesitation assumed the presence of nitric acid in these bodies. Berzelius represents the carbazotic acid as a copulated compound of hycirated nitric acid with a sort of saline body in which an- other equivalent of nitric acid is combined with an organic oxide having the formula c,,H KO3. Carbazotic acid is therefore a copulated acid of similar consti- tution with the sulphovinic acid (bisulphate of oxide of ethyl) and n-ould be rcpresented as fOllo~-s:-C, H NO, NO + HO NO,.Also in the otlier acids of this nature which contain only one equivalefit of nitrogen Berzelius assumes the presence of nitric acid. According to his view nitrobenzoic and nitro- salicylic acids would be represented as follows :-Nitrobenzoic acid . . C, H 0 + NO NO Kitrosalicylic acid . . C, M 0,+ HO NO There is no direct proof for this assumption and therefore otlier chemists believe that the nitrogen in these compounds does not exist as nitric acid but as nitrous acid NO ;thus ni- trobenzoic acid according to Mulder is C, H 0, HO NO ‘l’lie coli:pounds produced by the contemporaneous action ot’ r;itrogen and oxygen upon organic bodies are tiowever not always acid; a great class of bodies furnish under such cir- cumstar.ces products in 11 hich the acid properties of the nitric acid have entirely disappeared to these belong a number of organic bodies which consist only of carbon and hydrogen For example if benzoZ is brought into contact n-ith fuming nitric acid they combirie with separation of water and form a Mew Pl*oduct of Deconaposition of DinitrwbenxoZ.113 311 indifferent body i. e. nitrobenzol (nitrobenzide) discovered by PA it sc herlich. Naphthalol (naphthaline) toluol and a considerable number of carbides of hydrogen behave in a like manner. In which form is the nitrogen contained in these bodies as for instance in nitrobenzol ? The perfect neutrality of this substance its ether-like taste and odour induced some chemists to suppose that its ele- ments might be similarly arranged to those of the compound ethers.Nitrobenzol according to this view may be consi- dered as a compound of an organic oxide with nitrous acid corresponding to nitrous ether. Nitrite of oxide of ethyl C H 0 NO, nitrous ether. Nitrite of oxide of benzide C, H 0 NO, nitrobenxol. These views which appear at the first glance very reason-able lose however by a closer examination a considerable portion of their probability. Independent of the fact that oxide of benzid is merely an hypothetical compound while we know the oxide of ethyl in an isolated state the behariour of these two bodies towards potassa is sufficient to show a decided dissimilarity in their constitution.Nitrous ether like all the other compound ethers is decomposed by potassa giving rise to nitrite of potassa and alcohol (Liebig). Nitro-benzol when similarly treated yields no acid of nitrogen ; an aqueous solution of potassa leaves this body quite intact and when employed in alcoholic solution the latter is oxidized and azobenzol (axobenzide) i. e. nitrobenzol minus oxygen is formed*. We see here that all analogy between nitrous ether and nitrobenzol disappears entirely. Nitrobenzol uridergoes still another change which does not in any way agree with the benzide theory. According to Devillet this body when repeatedly treated with fuming iii- tric acid yields a crystalline substance to which he has as-signed the name binitrobenzol (binitrobenzide).This body $ according to the theory in question was considered to be a compound of 2 equivalents of nitrous acid with a higher oxide of benzide i. e. that its constitution must be according to the formula C, H 0, ZNO,. That his view is not tenable without mentioning other objections to it is evident inas- much as the above formula does not express the composition of the new compound; for according to Deville’s analysis we find that instead of five it only contains four equivalents of hydrogen. * Ann. der Chemie tmd Pharm. 1.01. liii. p. 28. + Amr. de Chewi. et de Phys. 3 ser. t. iii. p. 157. 1 Berzeliua Jahresbericht 18-13. Clmn. Xoc MP~. VOL.111. I I 14 Drs hluspratt ad Iiofincarin 012 Nitraniline Keccritly certain Frcnch chemists Laurent for example have represented these bodies under a diEcrent aspect. A great number of irivestigations had led to the conclusion that the hydrogen of many compounds may be wholly or partly replaced by a corresponding number of equivalents of chlo- rine and bromine without altering the fundamental properties. This law had been established for a number of acids and in- cliffererit bodies and an investigation published some months since* by one of us has proved that the same law extends also to bodies possessing basic properties which at first sight appeared improbable. The same view may be applied to many products which have assumed nitrogen and oxygen froin nitric acid.These compounds may indeed be regarded as simple products of substitution in which the hydrogen instead of being replaced hy chlorine or bromine is replaced by a compound radical namely by hyponitric acid. Whilst in the assumption of chlo- rine into an organic body the replaced hydrogen is taken up by another equivalent of chlorine forming hydrochloric acid ;in the employment of nitric acid the fifth equivalent of oxygen combines with the replaced hydrogen forming water. Ben-zoic acid HO C, H O, furnishes when treated with chlo- rine an acid w c,,(Ef) 03 which can scarcely be distinguished from the original com-pound. Moreover nitrobenzoic acid which is produced by the ac- tion of nitric acid upon benzoic acid has been in many cases confounded with benzoic acid.The constitution of this acid according to the theory of substitution is Ha cM{:~4}osi nncl it therefore may be regarded as strictly analogous to ehlorobenzoic acid. In a similar way n-e have chloro- brorno-and nitro-salicylic acid. Salicylic acid . . HO C, H 0 Chlorosalicylk acid . HO C14{Ft}05 Bromosalicylic acid . 1-10 C14 { 0 Nitrosalicylic acid . 110 C, {Kb4H II0,. Cnrbnzotic acid contailis not 1css than 3 eqlii\ialcnts of ni-* Transactons of the Chemical Society vol ii p. 266. ii mw Product qf Decomposition of Diuiirobenzol 115 trogcn ; now if we suppse the whole of this clement to exist in the form of hyponitric acid its empirical formula HO C, I-I IVJ 013, may be theoretically represented by the follow- ing :-NO,c,,(:fio4)oy and thus it would be a simple product of substitution of the cornpound HO C, H 0 which was discovered by Runge in coal-gas naphtha described by him under the designation of carbolic acid the same body which was subsequently analysed by Laurent and termed by him hydrate of phenyl.In fact this substance loses under the influence of chlorine bromine and nitric acid one equivalent of hydrogen after another into the place of which a corresponding number of equivalents of the elements or the compound N0,enter. We obtain in this way a series of products of substitution the last member of which on the one side is chlorophenusic acid and on the other carbazotic acid. Hydrate of Phenyl 1HO C, H 0.Phenol. Bromophenasic acid Bromophenol Chlorophencsic acid I3ichlorophe no1 Chlorophenisic acid Trichlorophenol Chlorophenusic acid Pentachlorophenol Nitrophenesic acid Dinitrophenol Nitrophenisic acid Trinitrophenol Carbazotic acid The same view may be taken of the products restilling from the action of nitric acid upon benzol. Nitrobenzol is simply benzol in which 1 equivalent of hydrogen is replaced by hyponitric acid and in dinitrvbenzol 2 equivalents of hydrogen are replaced as the name implies. Benzol . . . C, He. Nitrobenzol . Cli{ Eb4 Dinitrobeiizol . C, {:Go4* The chemical character of these three compounds is not essentially different. As thc substitution of chlorine and bromine for the hy-J2 116 Drs.Muspratt and IIofmann on Nilraniline clrogen of organic bodies has only recently been extended to bases so until now the replacement of hydrogen by hypo- nitric acid has been limited to acids and neutral bodies; it therefore appeared to be a point of great interest to ascer- tain whether indeed NO also could replace hydrogen in basic compounds without destroying their electro-positive character. There have been in fact some investigations made in this direction. Laurent lately discovered a new base among the products of distillation of hydrobenzamide re-markable for its high atomic weight. This base which may be obtained in fine crystals and is by Laurent called lophine is converted when boiled with nitric acid into a yellow cry- stalline powder which manifestly must be considered a pro- duct of substitution of lophine.Laurent’s analysis gives the following composition to this base C H,6N, and the yellow powder is represented by C46{;#O4)% In this body (nitrolophyl trinitrolophine) according to the view in question 3 equivalents of hydrogen are replaced by hyponitric acid; byt with this interchange lophine has lost all its basic properties trinitrolophine being an indifferent substance. In pursuing this track of investigation wc endeavoured to supply the hiatus existing here by finding a basic compound into which NO might enter without affecting its properties. The various ways in which aniline is formed its characteristic properties and above all having succeeded in replacing hy- drogen by bromine and chlorine in aniline we deemed this body the best suited to our experiments.In the first place we attempted to accomplish our purpose by the direct action of nitric acid on aniline but we did not in this way succeed when aniline is mixed with pretty strong nitric acid a mass of crystals are formed which are nitrate of aniline. On heating this salt in the presence of free nitric acid it dissolves with violent action and the escape of nitrous fumes and is as we know ultimately converted on continuing the treatment into carbazotic acid. Were it possible ta ob-tain nitraniline by this process it obviously could only be by interrupting the action of nitric acid at the proper time but after a number of experiments with acid of every variety of strength and adding water at every stage of the process we could not succeed ;either the aniline separated unchanged or its molecular constitution underwent an entire change and the water separated resinous matters rather of an acid than a basic character.We soon abandoned this method and a new Product of Decomposition of Dinitrobenzol. 11 7 remembering that the chlorine and bromine bases were pro- duced only indirectly we sought to accomplish our present purpose in the same manner. After the fact had been established that isatine was con- verted into aniline by fusion with caustic potassa the produc- tion of the chlorine and bromine bases followed as a matter of course; in the same way if we could succeed in producing nitrisatine c,6{:&4}N04 by replacing the hydrogen of isatine with hyponitric acid the distillation of this compound with potassa might yield nitra- niline CldHaNO + 4(KO HO) =CI2H7N + 4(KO C02) + 2H -v-J Isatine.Aniline. Nitrisatine. Nitraniline. On studying however the action of nitric acid upon isatine we soon found that the yellow powder which is formed is not simply a substitution product of isatine but belongs evidently to one of the families of bodies containing less carbon which proceed from the indigo series. It was therefore obvious that by distilling this compound with hydrate of potassa we could not effect our purpose. A third mode for the preparation of nitraniline occurred to us.One of the manifold sources of aniline is the destructive distillation of anthranilic acid which simply loses 2 equiva-lents of carbonic acid ;isomeric with this acid is salicylamide recently described by Cahours*. The composition of these two bodies is represented by the formula C, H NO,. Now if the salicylamide underwent the same decomposition by heat as anthranilic acid it might obviously be supposed that the nitraniline would result from the distillation of nitrosali-cylamide a substance also lately prepared by Cahours. C14 H6 04 NHZ -2C03 5 C12 Hb NH2 or C, H7 N --J Salicylamide. aniiine. Nitrosalicylamide. Nitraniline. There were some researches made in this direction the results of which we published at the beginning of last yeart.The exceedingly small amount of aniline however which * .dim. rler Chern und Phurw. vol. XI. p. 64. f-Transactions of &lieChemical Society vol. ii. p. 249. 1 18 Drs. Muspratt and Ilofinann on Nitraniline t,he distillation of salicylamide had yielded (the principal pro- ducts being hydrate of phenyl and ammonia) could never warrant a similar treatment of nitrosalicylamide in order to obtain a sufficient quantity of nitraniline for analysis and a complete study of its properties. There yet remained to us one resource. We have already mentioned a compound which is produced by the continued action of nitric acid upon nitrobenzol i. e. dinitrobenzol which we may consider as nitrobenzol in which a second equivalent of hydrogen is replaced by hyponitric acid.Che-mists are well-acquainted with the interesting transformation which nitrobenzol suffers with reducing agents. By assuming hydrogen and eliminating oxygen it is perfectly converted into aniline. What we may ask would be the action of reducing mems upon dinitrobenzol ? Various changes might be expected. If (ill the oxygen were eliminated we might form a substance possessing the formula C, H N ; but it was also conceivable that the reduction would extend only to 1 equivalent of hyponitric acid and that the other equivalent might form part of the new body; in other words that we might produce nitraniline We were just about to make the experiment when some researches of Zinin" were published on the action of hydro-sulphuric acid upon dinitronaphthalol (nitronaphthalese) and dinitrobenzol which appeared very unfavourable to our views.Zinin found that by the action of hydrosulphuric acid upon dinitronaphthalol a new base is formed containing no oxygen. By analogy this body should possess the composition- c HI0 Ns - New base. { i>04>+ C l2HS = C, FIlo N + 8HO + 12s. L-.-,..-d L.-d Dinitronaphthalol. New base. But Zinin found on andysing the double salt of this base with bichloride of platinum that its equivalent was only half Erdmann's Journ.fur Parakt. Chemic vol xxxiii. p. 29. u new Product of’ Decomposition of Dinitmbenzol. 119 showing that a division had taken place whence he gave the name seminaphthalidine to the new body.Seminaphthalidine is a well-characterized organic alkaloid forming with acids fine crystallizable salts. Zinin obtained by the action of hydrosulphuric acid upon dinitrobenzol the same result but in this case far less decided. A difficultly crystallizable substance is formed also possessing a basic na- ture which however could not be obtained in the state of purity. An approximative analysis of this substance showed it to be analogous to the seminaphthalidine i. e. C H N. Zinin himself remarked that this substance required a closer examination. These researches appeared to cut off all hopes of our ever obtaining nitraniline ; nevertheless we considerecl a continuation of our experiments in every way desirable so as at least to solve the questions that remained unanswered in Zinin’s experiments.By doing so we very soon obtained results which had escaped the observation of Zinin and which brought us to the point we aimed at. For our research we had to prepare a large quantity of di- nitrobenzol. The transformation of nitrobenzol into dinitro- benzol proceeds very slowly even when it is boiled repeatedly with the strongest nitric acid. It is obtained however very speedily by dropping benzol or nitrobenzol into a mixture composed of equal parts of fuming nitric acid and concen- trated sulphuric acid as long as the liquid remains homoge- neous. The liquid is now boiled for a few minutes and then allowed to cool. A thick mass of dinitrobenzol is formed which by washing with water is freed from all adhering acid.One recrystallization from alcohol furnishes this body in long shining needle-shaped prisms of absolute purity. A combustion of these crystals gave us the following re- sults :-02978 grm. dinitrobenzol gave 0*4728 grm. carbonic acid and 0.0650 grm. water. These results afford in 100 parts-Carbon . . . 43.26 Hydrogen . . 2*42 Calculated. Fonnd. 12 equivs. of Carbon . . 900*00 42-77 43*26 4 ... Hydrogen . 50’00 237 2-42 2... Nitrogen . . 354.00 16.82 8 ... Oxygen . . 800*Oo 38.04 -II__ 2 104.OO 1OO*W Preparation qf Nifradhe. Whcn an dcohdic solution of dinitrohcnzol is saturated 120 Drs. Muspratt and Hofmann on Nilraniline with arnmoniacal gcm it assumes a dark red colour and by then passing a stream of hydrosulphuric acid gas through this solution a large quantity of crystals of sulphur are de- posited.By continuing to pass hydrosulphuric acid gas through the solution until only a small quantity of sulphur precipitates it will contain very little u ndecomposed dinitro- benzol. By adding hydrochloric acid to this solution and boiling a new portion of sulphur mixed with a trace of dini-trobenzol is thrown down. The whole is now filtered and to the filtrate potassa is added a brown matter separates which unites and settles in a resinous mass at the bottom of the vessel. We washed this matter with cold water until all the alkali was removed. It dissolved completely in alcohol and ether imparting to them a reddish-brown colour; hot water dissolved the greater part of it but even after continued boiling in this solvent sinall quantities of a brown resin re- mained undissolved.The hot aqueous solution possessed a fine orange-yellow colour ; upon cooling it afforded beautiful yellow crystals about an inch in length which when recry- stallized from water were perfectly pure. Composition of Nilraniline. The crystalline matter prepared in the process described possesses all the properties of a true organic base obviously quite dissimilar to that obtained by Zinin. The physical pro- perties of the two bodies could scarcely be more unlike. Xlementary analysis proved immediately the difference of the two substances and showed that the crystals in fact belonged to the body which we had endeavoured to procure in such a variety of ways.By a combustion of the yellow crystals with oxide of cop-per the following results were obtained :-J. 0.3055 grm. of substance gave 0*5865 grm. of carbonic acid and 0*1275grm. of water. 11. 0'3748 grm. substance gave O*7119grm.carbonic acid and 0.1493 grm. water. 111. The nitrogen was determined by Dumas's method in an atmosphere of carbonic acid. KssuZts.-0*4260 grm. of substance gave 80 cubic centi- metres of moist nitrogen. Barometer Y24"' Thermometer 16O centig. These numerical results represent the following per cents. I. 11. 111. Carbon . . 52*70 51.80 Hydrogen Nitrogen . 4*6G'.. 4.42 e.* 20$2 n new Product qf Decomposition of Dirritrobenzoi. 121 agreeing exactly with the formula of nitraniiine c,*{:bI)N.The mean of our analysis compared with the calculated num- bers stands as follows :-Theory. Mean of the exp. c r 1 12 equivs. Carbon 900*00 52.05 52-25 6 ... Hydrogen 75'00 4.33 4.54 2 ... Nitrogen 354.00 20.47 20.5 2 4 ... Oxygen 400*00 23.14 1729.00 loo.00 In order to control this formula we prepared the double compound of the new base with bichloride of platinum. On igniting this salt 05240 grm. gave 0-1500 grm. =28*62per cent. of platinum. Atomic weight from experiment . . 1739.5 Atomic weight theoretical . . . 1729*0. The metamorphosis of dinitrobenzol under the influence of reducifig agents is thus perfectly analogous to the transfor- mation of nitrobenzol.In fact the decomposition is very simple if we regard dinitrobenzol as nitrobenzol in which one equivalent of hydrogen is replaced by hyponitric acid. C,(ib4}N04+G HS=C, {zb4}N+4H0 +6s c-rA Dinitrobenzol. LNitrahline. Properties of Nitranihe. Nitraniline as we have stated is obtained from a hot aqueous solution in the form of long yellow crystals. It is very sparingly soluble in cold water so that nearly the whole is separated by crystallizing from this solvent. Alcohol and ether also dissolve this base; from the former it crystallizes in silky needles and from the latter in the same form but not so well defined. Nitraniline dissolves in all acids from which potassa separates it in yellow flakes which under the microscope have a confused needle-like structure.At the ordinary temperature the base possesses no odour but when slightly warmed it evolves a peculiar arohatic odour which somewhat resembles aniline. Its taste is burning. When the crystals are heated they melt into a deep yellow oil which passes into a yellowish vapour condensing in beautiful iri- descent plates upon the cold interior surface of the vessel. Nitraniline sublimes IT ithout fusing when heated in a watcr- 122 Drs. Musyratt and Ihfmann on Nitraniline bath yielding a sublimate of most beautiful crystals. At a higher temperature the base distils leaving no residue and the liquid which passes over solidifies in the receiver or in the neck of the retort into a scaly mass. The boiling-point of the base lies higher than 285' C.(545' Fahr.) and the fusing- point at about 110' C. (230' Fahr.). Its vapour burns with a smoky flame. Nitraniline is specifically heavier than water ; it affords not the slightest reaction with test papers ;even rose paper which is so exceedingly sensitive for alkalies is not at all affected by it. The properties of nitraniline agree iu many respects with those of aniline chlor- and bromaniline. Like these bases it possesses in a high degree the property of imparting an in- tense yellow colour to fir-wood. This base also stains thc skin in no less degree than carbazotic acid nitrophenesic acid &c.; but it does not afford the beautiful reaction with hypochlorite of lime which characterizes aniline. Nitraniline displaces none of the metallic oxides from thcir acid compounds ; its basic properties are exceedingly weak.Aniline displaces this base from all its salts. Compounds of Nitraniline. Although nitraniline is so weak a base it combines with acids affording crystallizable salts which possess the same constitution as the corresponding salts of aniline. All its salts are decidedly acid to test papers. They are decomposed by the caustic and carbonated alkalies nitraniline separating in a crystalline form. We have investigated the subjoined salts in order to be completely satisfied with respect to the corn-Position and nature of the base. 1 Hydrochlorate of Nitranitine C12{~fl,?-N HCL-It is obtained by evaporating a solution 2 nitikline in hydro- chloric acid.The colour of nitraniline entirely disappears in this solvent and fine scales are obtained shining like mother- of-pearl. This salt is extremely solublc in water and alcohol. AnaZysis.-0440fi5 grm. of salt gtve 0*3350grni. chloride of silver or 20.37 per cent of chlorine. Theory. Foun(1, 12 equivs. Carbon . . 9OO*OO 41-23 7 ... I-l[ydrogcn. 87-50 4.00 2 ., Nitrogen . 354*00 16-22 4 ... Oxygen . 400.00 18*32 1 ... Chloi-inc 442.65 "q2.3 20-37 2284*15 1 90w) a new Product of Decomposition of Dinihobenxol. 123 Binoxalate of Nitranihe C12 -This salt is obtained on mixing a solution of nitraniline in alcohol with oxalic acid dissolve$ in the same solvent. This salt separates in the forni of yellowish crystals which are washed with ether and dried upon a porous tile.The combustion of this compound with chromate of lead afforded the following numbers :-0*4985grm. of salt gave 0-7550 grm. carbonic acid and 0.1790 grm. water. In 100 parts-Carbon . . . . 41.30 Hydrogen . . . 3.99 16 equivs. Carbon . . f! ... Nitrogen . 13 ... Oxygen. . 9 ... Hydrogen. 1200*00 354.00 1300*00 112.50 40.45 11-93 43.83 Theory. 3-79 41*30 Fou11d. 3-99 2966.50 100*00 The above numbers show the slight excess of carbon which often occurs with the substitution products of hyponitric acid especially when the combustion is carried on rather quickly. Unfortunately we had no more of the base to prepare this salt again but there is little doubt but that the analysed salt corresponds with the binoxalate of chloraniline*.Double Salt of Hydrochlorate of Nitraniline and Bichloride of Platinum C12 { Ebl)N HCl Pt CI,.-An aqueous so-lution of hydrochlorate of nitraniline is not precipitated by deutochloride of platinum ; but when an alcoholic solution of the former is mixed with the latter a yellow crystalline double salt is formed which is exceedingly soluble in both water and alcohol and therefore must be washed with ether. We have already alluded to the determination,of the 111rzt'inuni in this salt when treating of the atomic weight of the base. We append the calculated composition of this salt along with the platinum per-centage found. Theory. Fouiid. 13 equivs. Carbon . . 9OO*OO 20.91 7 ... Hydrogen. 87.50 2.03 2 ...Nitrogen . 354.00 8.23 4 ... Oxygen. . 400*00 9.30 3 ... Chlorine 1327.95 30-57 1 Platinum . 1253'50 25-66 28-63 -___ -___ 4302.95 100'00 Wc have not examined the other salts of nitranilinc. * Transactions of the Chemical Society vol ii. p. 227. 12-1. Drs. Muspratt und IIofrnann on lGtruniline. Products of the Decomposition of Nitraniline. We have not as yet made many experiments in this direc- tion owing to the great difficulty of obtaining the base in sufficient quantity ; we can therefore only give a few reactions. Nitric acid violently decomposes nitraniline and after con- tinued boiling affords an acid which we have not more closely examined. There is little doubt but that it is carbazotic acid. When this base is treated with bromine violent action takes place accompanied by an elevation of temperature and a strong disengagement of hydrobromic acid.After some time the whole is changed into a brown resinous mass which cry- stallizes from alcohol in the form of yellowish needles. This body is insoluble in water and perfectly neutral combining neither with acids nor alkalies. It is manifestly nitrodibro- nianiline corresponding with tribromaniline. We may regard the following as the formula although as yet we have not analysed the substance :-The production of nitraniline appears to us to be interest-ing in reference to the question of substitution which is still in debate amongst chemists. If we reject that theory we can scarcely understand the constitution of this base and its re- lations to aniline.The group of aniline compounds has thus been again aug- mented by the discovery of nitraniline. The following is a synopsis of the different members of this family :-Aniline . . Chloraniline . Dichloraniline Trichloraniline . . . Chlorodibromaniline . C19{ !:}N. Bromaniline * . . . CIQ{E:}N. Dibromaniline . . C12{!:Q)N. Tribromanilinc . a c,1( ::?}Nb OIZthe Blue Compounds OJ Cyanogen and Iron. 125 Nitraniline . . . Nitrodibromaniline . In concluding this memoir we may remark that the body which Zinin obtained by treating dinitrobenzol in the same manner i. e. the compound C H N is evidently the last product of the action of the hydrosulphuric acid upon dini- trobenzol our nitraniline being the first.Zinin's compoiind will doubtless be procured by the further action of reducing agents upon nitraniline. We shall shortly ascertain this. CIP{;b4)N + 6HS = 2C6H4N + 4H0 + 6s. -Nitraniline. Semianilirie. The small quantity of resinous matter which remains be- hind upon dissolving crude nitraniline in boiling water is probably Zinin's semianiline.

ISSN:0269-3127    

DOI:10.1039/MP8450300110

出版商:RSC    

年代:1845

数据来源: RSC

摘要:

OIZthe Blue Compounds OJ Cyanogen and Iron. 125 CLXV. On the Blue Compounds of Cyanogen and Iron. &.J ALEXANDER Esq. Ph.D. W. WILLIAMSON T is a well-known fact that the different substances which 1 pass by the general name of prussian blue when pre- pared in the usual way are not pure combinations of iron but invariably contain potassium of which the quantity varies according to the circumstances under which they are formed. It has been the subject of frequent experiment to decide whether this potassium should be considered as an admixture or as an essential constituent and in the latter case to dis- cover what part it plays in the constitution of the compound. Among those various researches we may confine ourselves to the consideration of those of Berzelius* and Gay-Lussac t.Gay-Lussac found that prussian blue retains potassium so tenaciously that the latter cannot by mere washing be re-moved from it ; for as soon as the precipitate had been freed from all potassium it was found to consist no longer of prus- sian blue but hydrated oxide of iron. From this fact he concludes that the purest prussian blue contains potassium. Berzelius on the contrary by washing continuously for three weeks a precipitate of ferrocyanide of potassium with a persalt * Poggendorffs Awnaleit vol. xxi. p. 490. t Ibid. vol. xxv. p. 385. Dr. Williamson on thc of iron succeeclocl in obtaining a substancc which though retaining the colour of the original compound was perfectly free from potassium.The water passing through in the later periods of the operation contained this potassium in the form of ferridcganide the formation of which salt he attributes to a process of oxidation resulting fiom the action of the air; thus admitting that a decomposition of the original precipi- tate accompanied the removal of the potassium Without the proof afforded by an analysis or some characteristic reaction we cannot venture to conclude that the residue after this de- composing reaction retained the composition of prussian blue. Derzelius thus agrees with Gay-Lussac in the fact that a decomposition of the prussian blue is a necessary condition for the removal of the potassium. The difference consisted only in the kind of decomposition which took place in Ber- zelius's experiments the residue after decomposition still main- tained a blue colour while in Gay-Lussac's in which by the action of a water which he himself concluded must have been alkaline the residue consisted of peroxide of iron.Both lead however to the same conclusion. Berzelius analysed two kinds of prussian blue containing potassium. The first which was soluble in water he found after separation by means of alcohol from the red and yellow cyanides which were simultaneously formed to contain for every 12 atoms of iron 1 of potassiurn. The other which was insoluble in water as it remained on the filter from which the soluble salt had been washed away contained iron and po-tassium in the proportion of 8 equivalents to l. The former of these substances he considers as a combination of 2 atoms of the yellow prussiate with 3 atoms of prussian blue,- 2(Fe k' Cy,) + 3pe Cy,).The second is a combination of 1 atom yellow prussiate with 2 prussian blue,- Fe K Cy3+2(Fe Cy,). This great chemist admits however what indeed the com- plex nature of these formulae sufficiently indicates that fur- ther light is needed on the nature of these compounds than these analyses afford. I shall now describe the results of some experiments which I have performed in the laboratory of Professor Liebig for the purpose of gaining some further insight into thc compo- sition and nature of these salts and of deciding the question of the existence of the pure compounds of iron of which the formulc7e have been given on purely theoretical grounds.It is well knm-n that when f'crrocyanide of' potassium is Blue Con~pou?2dsof Cyanopn and hn. 127 boiled with dilute sulphuric wid only a part of the cyanogen iu given off’as hydrocyanic acid and that a greenish substance remains behind containing all the iron and a considerable quantity of the potassium in combination with cyanogen ;also that this substance by exposure to the air gradually changes into a deep blue. This process is much favoured ay Gay-Lussacobserved by the presence of free acid and is accom-1)anied by the formation of a potassium salt of this acid. This green substance consists according to the analysis of Everitt which 14.Geiger repeated in this laboratory of 3 equivalents cyanogen 2 iron and 1 potassium.My analysis confirms this composition. 2.372 grammes ferrocyanidc of potassium were distilled with water and sulphuric acid equivalent to the quan- tity of potassium in the salt and the distillation was continued until no more prussic acid passed over. The residue after this treatment was washed out on a filter air being excluded dried and cautiously heated in a platinum crucible with con- cen trakd sulphuric acid which decomposed all the cyanogen and converted the iron and potassium into sulphates. The aqueous solution of these salts was decomposed by ammonia filtered evaporated and heated to redness. 0-532 gramme sulphate of potash was thus obtained which corresponds to 10*08per cent. of potassium instead of 10.67 per cent.which the above formula requires. The compound may be considered as ferrocyanide of potas-sium in which 1 atom of potassium is replaced by iron and may be expressed by the following formula :--_ Cfy{ Its reactions are also such as we must expect from such a compound for by treating it with caustic potash asolution of pure ferrocyanide of potassium is formed whilst protoxide of iron is set free. It will be designated in the following lines ferrocyanide of iron and potassium. The blue compound into which this salt is changed by oxidation ha3 been incorrectly considered as prussian blue. It however differs materially in its composition from that body as I will proceed to show. Its formation takes place very easily for it is caused by every re- agent such as chlorine nitric acid sulphuric acid with oxy- gen &c.which eliminates potash from the white salt. For its preparation dilute nitric acid which consists of 1 volume concentrated acid and 20 of water may be used with most advantage. This liquid in which the white salt prepared as above described is suspended is heated in an open basin during which the Iliqnitl is fi-equently stirred. L4ta low tem-pxture no ni)p:,rent action wsucs J but when the liquid has Dr. Williamson on the nearly reached the boiling-point an evolution of nitric oxide commences which gradually increases in briskness and is accompanied by a speedy change of the white colour to dark blue. As soon as this action has commenced the basin must be removed from the fire to prevent too violent an action which would cause the admixture of another substance.If the correct proportion of white salt to acid has been used the action continues without further heating until the transforma- tion into the blue compound is complete. If however the colour should indicate that some of the white salt remains a small quantity more acid must be added and the mixture if necessary again heated. In order to proceed with certainty a small portion of the blue substance should be decomposed with potash ;should the peroxide of iron which is thus set free contain protoxide the treatment with nitric acid must be con- tinued; the presence of ferridcyanide of potassium in the so-lution indicates on the contrary that the action has gone too far in which case the operation must be recommenced with a fresh portion.In this manner a body of a beautiful violet blue colour is formed containing less potassium than the pre- ceding one. The liquid contains nitrate of potash but no trace of iron. The substance prepared in this way was thrown on a filter and washed out until the washings left no residue on polished platinum. The compound was not in the least degree affected by this treatment. It retained its original colour and contained no peroxide of iron soluble in muriatic acid. After being carefully dried at loooC. it was analysed in the manner which I shall now proceed to describe. The cyanogen was completely oxidated by a gradually in- creasing heat applied to it in an open flat-bottomed porcelain crucible.It was thus converted into a mixture of peroxide of iron and carbonate of potash from which the alkali was extracted by repeatedly boiling with water and determined as chloride. The residue was determined as peroxide of iron. The cyanogen was determined indirectly by suspending a weighed quantity of the compound in water and decomposing it with potash. The peroxide of iron thus separated neces- sarily corresponded to the quantity of percyanide as all proto- cyanide remained in solution in the form of yellow prussiate. I. 3*417grms. gave 0.694 chloride of potassium and 1*630 peroxide of iron corresponding to 106 per cent. potassium and 32.4 per cent. iron. IT. 4.225 grms. gave 0.871 chloride of potassium and 1.986 peroxide of iron corresponding to 10-87 per cent.potassium and 325 per cent. iron. Blue Coinpounds of Cyanogen und htz. 129 Determination of Cyanopz. 1. 3-744grms. pzve 0.940 pcroxide of iron corresponding to 17.4 per cent. iron as cyanide. 11. 6.125 grms. gave 1.585 peroxide of iron corresponding to 17.9 per cent. iron as cyanide. The formula Fe Cy K + 4Aq requires-I. 11. Fe 108=8=32*0 32*4 32*5 K 39*2=11*5 10.6 10.9 precipitated by potash- Fe 54.4=16-28 17% 17.9. The deficiency of potassium and corresponding excess of iron are sufficiently accounted for by the imperfect separation by water. The excess of peroxide of iron corresponding ta the cyanide was caused by its containing some of the potash employed in its separation.In order however to remove all doubt of the correctness of the formulz deduced from these numbers several combustions with chromate of lead were performed with the greatest accuracy. These are as follows :-I. 0.427 grm. gave 0.331 CO and 0.046 water corre-sponding to 21.14 per cent. carbon and 1078 water. 11. Q320 grm. gave 0.247 CO and OQ36 water corre-sponding to 2'L*05per cent. carbon and 11*15water. III. 0-721 grm. gave 0559 CO and 0*081watcr corre-sponding to 21-14 per cent. carbon and 11.3 water. Calculated. I. 11. 111. C, . . 72 21.17 21.14 21.05 21.14 4Aq . 36 10'59 10.78 11.15 11.3 The approximation here is sufficient. This compound is particularly remarltable for its brilliant violet-blue colour.In-a finely divided state as is obtained by suspension in a large quantity of water it is transparent with a green colour. It does not possess when dry the cop- pery lustre so characteristic of prussian blue. It may be viewed as ferriclcyanide of potassium in which 2 atoms of potassium are replaced by iron and it bears the same re-lation to the above-described white compound Cfy{g as Gmelin's salt to the yellow prussiate. The manner of its formation is also the same for 2 atoms iirrocyanide of iron and potassium unite giving up 1 atom of potassium just as in the case of yellow prussiate. 2 (Cfy(g) + C1= 2Cfy{kFe+ KCl. We may call it according to the customary nomenclature Chenz. Soc. Mern. VOL. III. K Dr. Williamson on fhe ferridcyanide of iron and potassium.It has been mentioned above that on treating it with potash ferrocyanide of potas-sium is formed and hydrated oxide of iron is set free It is evident that in this reaction 2 atoms of iron are replaced by 3 of potassium whilst the oxygen of the potash combines with the iron. On heating this blue compound with a solution of yellow prussiate it changes it into ferridcyanide ;if the blue compollnd be in excess no trace of yellow prussiate remains behind. 3.473 grms. ferridcyanide of iron and potassium were sus- pended in an excess of ferrocyanide and digested with it for a considerable time. Collected on a filter it was of a pale blue colour and gave 1.39 grm. sulphate of potash corre-sponding to 0.624 potassium of which before the treatment .with ferrocyanide it only contained 0'411.Hence it is evi-dent that the reaction consists in potassium being taken from the yellow prussiate and half of the ferridcyanide of iron and potassium changed into ferrocyanide. This reaction may evcn be applied with advantage to the preparation of larger quantities of pure red prussiate for it presents neither of the disadvantages attending the decomposition by chlorine viz. the admixture of chloride of potassium which is unfavourable to crystallization and also the well-known green substance which is'formed by the slightest excess of chlorine The blue salt may of course be used repeatedly for this operation as it is immediately restored by warming with nitric acid By long.continued boiling with nitric acid this blue com- pound is changed into a rich dark green which contains a greater proportion of cyanogen and a small quantity of potas-sium. It is reduced by the action of light which gradually changes its colour to a blue. For analysis it was heated with concentrated sulphuric acid until all cyanogen was destroyed ; the iron and potassium were determined as peroxide and sul-phate of potash. I. 2.966 grms. gave 1.527 peroxide of iron and 0.147 sul-phate of potash corresponding to 35'78 per cent. iron and 2.23 per cent. potassium. 11. 3.172 grms. gave 1*637peroxide of iron and 0.159 sul-phate of potash corresponding to 35.97 per cent. iron and 2'25 per cent. potassium. Burned with chromate of lead it gave the following num- bers :-I.0'421 grm. gave 0.361 carbonic acid and 0*058 water corresponding to 23.3 per cent. carbon and 13.6 water. 11. 0'151 grm. gave 0*121 carbonic acid and 0*030 water corresponding to 33.2 per cent. carbon mid 13.3 water. Bhe Cornpotmils of Cynnogen nntl Iron. 13’1 This quantity of potassium is too small to justify the con- clusion that it is essential to the compositiori of the salt as it only amounts to about 1 equiv. to 24 iron. Its equivalent of iron was therefore added to the other iron and in this man- ner numbers found which correspond to the formula Cy Fe t 5 aq as is shown by the following :-Fonnd. Calciilated. 1. 11. Cl4 84 = 23.14 239 232 Fe 136 = 3.795 37’17 3797 Aq 45 = 12.4 13.6 13.3 On treating this body with potash peroxide of iron is se-parated and a brownish-red liquid formed in which proto- and persalts of iron give a blue precipitate.This liquid is decomposed by boiling peroxide of iron is precipitated and the colour of the precipitate becomes much,lighter. I am not aware however what is the nature of the decomposition. The brown-red colour of the liquid has much similarity with that obtained By mixing ferridcyanide of potassium with a persalt of iron. The green substance which Pelouze obtained by decomposing yellow prussiate by chlorine and for which he gives the empirical formula Fe Cy, is decomposed in n similar manner by potash. If in accordance with the view of many chemists we consider this substance analogous to magnetic iron ore as Fe Cy + Fe Cy the compound which I have described may be viewed as containing a double quan- tity of percyanide 2(Fe CyJ + Fe Cy.I will not however venture to express any opinion as to the propriety of consi-dering it as a peculiar compound or not. It is well known that for technical purposes an esteemed blue colour which is sometimes called Turnbull’s blue is prepared by decomposing ferridcyanide of potassium with a protosalt of iron. In this compound which by its colour may be easily distinguished from prussian blue the presence of potassium has been discovered but without bringing to light any connection with the composition of the body. It appeared to me not devoid of interest to examine the pro- perties of this substance and subject it to analysis.To a dilute aqueous solution of ferridcyanide of potassium which had been purified by frequent crystallizations was added a solution of sulphate of iron the red salt remaining in ex-cess. In washing out this precipitate T proceeded with par- ticular care as whilst removing all substances mixed with the compound it was necessary to avoid any action upon it which might render soluble any constituents of the salt as was the case with Berzelius’s washing in the air. This object I colnplctely succeeded in attaining simply by means K 2 Dr. ?Williamson on the of washing with distilled rater in a rcssel f'rom which air was excluded. The precipitation had been performed in a tall glass cylinder which was completely filled by the li- quids and could be perfectly closed by a glass plate ad- justed to its ground edge.In this vessel the precipitate was washed by subsidence and decantation during the first period of which the water ran off colourless or only slightly coloured by the remaining quantity of red prussiate. As soon how-ever as the greater part of the soluble salts had been washed away the liquid no longer cleposited all the blue compound suspended in it but even after standing sevcral hours ran off with a blue colour. In the supposition that I had here a so-lution of prussian blue I threw it upon a filter and found that it ran through unchanged. Unwilling however upon the simple testimony of this fact to conclude that it was a solution I transferred it to a filtering apparatus so contrived that by mean3 of a hydrostatic pressure which could be va-ried at pleasurc it was driven through a layer of sixfold fil-tering paper supported by a linen cloth.This experiment proved that the blue compound was indeed not in solution but merely in a state of suspension so fine as to pass through the pores of a simple filter for it was completely separated by the denser mass of the compressed folds of paper and a colourless liquid passed through The washing was contiiiucd until the water filtered through in this manner left no visible residue on evaporation on polished platinum. Subsequent experiments showed that this operation may without affect- ing the result be performed more quickly and easily by the use of hot water as in this case the precipitate assumes a .denser form and deposits more easily from the liquid.I. 1.706 grm. of this substance gave 0*825 peroxide of iron and 0*189sulphate of potash corresponding to 33*6per cent. of iron and 4.96 per cent. of potassium. 11. 1-870grm. gave 0*909peroxide of iron and 0*221 sul-phate of potash corresponding to 33*7 per cent. of iron and 5-3 per cent. potassium. The average of these numbers namely 33% iron and 5-1 potassium are in the proportion of 9.3 equivalents iron to 1 potassium. It will be shown later how these numbers are to be considered ;n-e see in the meanwhile that they indicate a different composition from that of ferridcyanide of iron and potassium. I next endeavoured to precipitate in such a manner as if possible to replace all the potassium of Gmelin's salt by iron which was done by forming the precipitate in mi excess of protochloride Qfiron and digesting it for several hours with that salt.'l'hc substance thus prepared mas washed out in 133 Blue Conyounds of Cyunopnizd Iron. the manner dcscribccl in the preceding instance and was found though not absolutely free from potassium to contain so extremely small a quantity of this element as to render a determination of it next to impossible ;so that the difference produced by neglecting it fell far within the limit of the or-dinarylimit of analysis. After drying at the ordinary tem- perature over sulphuric acid it was subjected to analysis. I. 0*765 grm.gave 0.383 peroxide of iron corresponding to 34% per cent. of iron. 11. 0.763 grm. gave 0.979 peroxide of iron corresponding to 34.4 per cent. of iron. Burnt with chromate of lead,-I. 0*535 grm. gave 0*344carboiiic acid and 0.159 u-ater corresponding to 17.5 per cent. carbon and 28.9 water. 11. 0.563 grm. gave 0.359 carbonic acid and 0*157 water corresponding to 1744 per cent. carbon and 27.9 water. 111. 0.4'17 grm. gave 0.307 carbonic acid and 0.135 water corresponding to 17.5 per cent. carbon and 282 water. The proportion of 5 equivalents of iron to 6 of cyanogen requires to 34.5 of iron which is the average found 18.2 car-bon instead of 11.5 as is found. If it be considered that the error of iron and carbon determinations are here added to- gether the accordance will I think be held to be sufficient.My reason for not calculating any formula for the water was that owing to the readiness with which the compound is de-composed I was compelled to analyse it without drying at an elevated temperature which would have produced an evo-lution of hydrocyanic acid. On decomposing this substance in the fresh prepared state by potash proto-and peroxides of iron are set free and ferrocyanide of potassium formed. A portion of this compound was after carefully washing out and without drying decomposed by carbonate of potash. The proto- and peroxides of iron thus separated after long-con- tinued heating in the air weighed 1.627 grm. of peroxide. The liquid boiled in and treated with sulphuric acid gave 1.077 grm.peroxide of iron. The proportion of 3 to 2 re-quires 1.623 and 1.082. Of 5 equivalents of iron 3 were Be- parated in combination with 4 atoms of oxygen of the potas- sium which takes their place while the other two being con- tained in the composition of the radical remained in solution. I will now pass to the consideration of the manner in which we may consider these elements to be combined. It is well known-that ferridcyanide of potassium is reduced by the ac- tion of sulphurctted hydrogen that is to say it takes up hy- drogeii arid is thus converted into a niixturc of 3 atonis fer- rocyaiiidc of potassiuni arid I atom hyclrofcrrocyanic acid (or ferrocyanidc of hydrogen). Dr. Williamson on the 3Cfy 2K igx cK} = {Cfy 2H 2s The fad of the red cyanide b&g thus reducible is how-ever a property which may in the above instance exercise a considerable influence on the composition of the product as is shown by the following instructive experiment of Liebig- To a boiling solution of ferridcyancide of potassium was added a small quantity of protosulphate of iron which wits not nearly sufficient to decompose all the cyanide.Ferrocyanide of po-tassium which remained in solution and precipitate of prus-sian blue f3Cfv4Fe1 were formed:- This reaction leads to a new Gay of considering the above analysed compound which is adapted to its composition when containing and also when free from potassium for if one atom more of protosalt of iron be added than assumed in the above formula of decomposition it forms by decomposition with the yellow prussiate ferrocyanide of iron and potassium which divided in the already-formed prussian blue produces a mix-ture containing iron and potassium in the proportion found by analysis :-3Cfy 4Fe ggK}={cfy{p5K0 On adding an excess of iron salt the second equivalent of potassium is also replaced by iron and a mixture of prussian blue and ferrocyanide of iron formed which contains cyanogen and iron in the proportion of 6to 5 as found.This view rests upon the supposition that prussian blue (SCfy4Fe) is always formed by the decomposition at the ordinary temperature as was found to be the case at the boiling-point. In the con-trary case we must assume that the potassium of the red cyaniclc is simply replaced by iron :-Wfv 3K + 3FeCl= ZCfv 3Fe + 3KC1 In the first case we have ferridcyanide of iron in the se-cond a double salt of the same with ferridcyanide of iron and potassium.The separation of Fe 04.by pptash seems to speak in favour of' the vicw that the precipitate is a mixture of prussian blue ;~ndfcrrocyanidc of iron as these substances would give this reaction ; fbr if thc cornpound wcrc a fcrridcyanidc of' iron it wuulc\ bc cspccted thilt potash w;ould set frec protoxide of Blue CompouzLds of Cgazhogeza and irou. iron and reproduce the red cyanide. It might indeed be rc- plied to this that the red cyanide is reduced by the protoxide in proportion as it is set free :-gT") + 3Fe0 = Z(Cfy 2K) + Fe 0,.I described above an experiment of Liebig showing that by the action of protoxide of iron the red prussiate is reduced to the yellow but I find that the reverse process takes place with equal facility that is the peroxide of iron decomposes the yellow cyanide forming the red one. A small quantity of perchloride of iron was added to a boiling solution of ferro-cyanide of potassium and the mixture heated for some minutes. The liquid filtered off clear gave a deep blue precipitate with protosulphate of iron :-1 have now endeavoured as far as possible to state the two ways of considering these compounds and will leave the de- cision to more conipeteiit judges. I next endeavoured to apply the method which had proved so serviceable in obtaining Turnbull's blue free from potas- sium viz.digesting the precipitate with an excess of the iron salt to the preparation of prussian blue of equal purity. A weak solution of yellow prussiate was poured into a great excess of perchloride of iron and the mixture allowed to stand for some hours exposed to a gentle heat. This precipitate after being completely washed in the usual manner gave on analysis to O-'/urperoxide of iron 0057 sulghate of potash which numbers are in the proportion of 27 iron to 1 potas-sium. If this were to be considered as a peculiar compound it must be,- 3(3Cfy 4Fe) + 3Cfy{;p All my endeavours to obtain a precipitate free from potas- sium were unavailing,as long as this element was present at the formation; I had therefore at last no alternative left but that of precipitating by pure hydroferrocyanic acid.This acid was prepared by mixing a solution of yellow prussiate from which by boiling all atmospheric air had been expelled with about an equal volume of muriatic acid which had been similarly freed from air and precipitating by zether. After it had been filtered off and washed with crther the acid only needed to be dissolved in absolute nlcohol and again precipitated by zther to be obtained perfectly pure. It was then dried dis- solved in water and precipitated with an excess of perchloride of iron. The precipitate thus formed may be distinguished Dr. Williamson 012 the from common prussian blue by its darker colour. It was washed in the usual manner and dried at a temperature of' from 30' to 40°.I. 1.400 grm. burnt in an open porcelain basin gave 0*6487peroxide of iron corresponding to 32.1 per cent. iron. 11. 2.0365 grm. gave 0.481 peroxide of iron correspond- ing to 32*0per cent. iron. 111. 1.0035 grm gave 0.463 peroxide of iron correspond- ing to 31.8 per cent. iron. Burned with chromate of lead,-I. OW34 grm. gave 0*4405 carbonic acid and 0.1919 water corresponding to 17.3 per cent. carbon and 27*9 per cent. water 11. 0'415 grm. gave 0.269 carbonic acid and 0.127 water corresponding to 17.7 per cent. carbon and 28-6 water. 111. 0*304grm. gave 0-233 carbonic acid and 0'119 water corresponding to 17*4per cent. carbon and 20.0 water. Nitrogen determination according to Will's method :-I.0*4065 grin. gave 0'3077 chloride of platinum and am- monium corresponding to 20.2 per cent. nitrogen and 0-574 platinum. 11 0543 grm. gave 1.780 chloride of platinum and am-monium corresponding to 20% per cent. nitrogen and 0-780 plat'inurn. Thc following tablc shows the degree uf approximation to tlic formula Fe C3'y:-Calculated. Found. r 11. IEr. Fe 190*4=31*56 32*1 32-0 31*8 C, 10SvO=l'/*S7 17.3 17'7 17'4 N 126*0=28.83 20.2 20% Aq, 180*0=29*74 27.9 28.6 28*0 In each combustion fresh-prepared substance was taken. The slight excess of iron and loss of carbon and nitrogen are doubtless to be attributed in spite of the precautions taken to prevent it to a decomposition having taken place during the drying by which hydrocyanic acid was set free as indeed might be recognised by the smell and peroxide ofiron formed.The oxygen combined with iron is in the table calculated as water hence the deficiency of water. This decomposition n-hich takes place very easily explains the formation of the so-called basic prussian blue a substance eonsidered as a compound of prussian blue and peroxide of iron but of which little is ltn0147n. 3Cfy 4Fc + 3aq-ZiC:yI1= 2Cf-y 3Fe + Fc 0,. By the action nf light a process of rcduction takes place 13kue Compounds oj Cyanogen and Iron. I37 as was remarked above in the case of another compound. With other cyanogen compounds a similar action occurs of' wliich I will mention a striking instance further on. On de-composing this substance by potash ferrocyanide of potas-sium is formed and peroxide of iron set free.Experiments, in which I endeavoured to determine quantitatively the pro- portion of iron separated by potash invariably gave more than the formula of the pure substance requires but this seems to be accounted for by the formation of the above-described basic compound. In aqueous oxalic acid the prussian blue is very easily so-luble By the addition of carbonate of potash to this liquid the colour is changed to a red-brown but no iron is precipi- tated at the ordinary temperature; as soon however as the liquid is boiled peroxide of iron falls down in the proportion of three-fifths of that contained in the blue compound. An unweiglieil quantity of dried prussian blue was dis-solved in oxalic acid and by boiling with carbonate of potash 0.208 peroxide of iron were precipitated.The liquid con- tained 0'137. The proportion of 3 to 2 requires 0'207 and 0*138. On R second determination 0'274 were precipitated by potash whilst 0.174 remained in solution. The propor- tion of 3 to 2 requires 0.268 and 0.179. This reaction with oxalic acid might reward further examination. A remarkable circumstance connected with it is that the liquid after being filtered off from the peroxide of iron separated by potash is precipitated blue by muriatic acid. I have now endeavoured to describe the formation of prus-sian blue under different circumstances and the influence which these exercise on its composition giving particular at- tention to the presence of potassium.It appears to me that this circumstance of the presence of potassium is not a matter of mere scientific interest but is also of great importance to the dyer for it materially affects the colour and dyeing power of the product in the manner I shall now proceed to state. The greater the quantity of potas-sium contained in the cyanide the lighter and more approach- ing to violet is its colour ;and on the other hand in proportion as the quantity of potassium is diminished the colour becomes deeper and more powerful. Of the different blue compounds describecl above the brightest and niost strilring is that formed from the residuc of the distillation of prussic acid (2Cfy{ Next to this in order stands the precipitate fp).furincd by proto-sulphntc of iron in an excess of ferridcyanide J5Fe The next link in the chain is a of potassium 4Cf'y w ' 13s Dr. Williamson on the compound formed by the decomposition of ferridcyanide of potassium by sulphuric acid which contains still less potas- sium and which I will presently describe. Darkest of all are the compounds which contain no potassium. The dyeing power of these substances by which term I intend to desig- nate the relative power of imparting a blue colour to any co- lourless substance with which they may be mixed is in the inverse ratio to their quantity of potassium; but in such a manner that those containing potassium have a smaller co- louring power than after deducting the cyanide of potassium contained in them would belong to the remainder ; whence we see that the potassium plays no indifferent part in their colouring power.When a solution of ferridcyanide of potassium is treated with concentrated sulphuric acid a green precipitate is formed consisting of percyanide of iron and a small quantity of cyanide of potassium. By continued boiling with an excess of sul-phuric acid its colour is changed into a rich blue. It is ad- visable to continue boiling for a considerable time after the change of the colour has taken place in order to ensure the complete transformation. Ammonia which may be easily proved to exist in the liquid is here formed at the expense of a part of the cyanogen. This compound was washed and clriecl in the manner described in former instances and gave on analysis to 1.962peroxide of iron 0*049sulphate of potash which is one proportion of potassium to about sixty iron too small a quantity of potassium to be considered as essential.I. 1.464 grm. gave O*702 peroxide of iron corresponding to 33*25per cent. iron. IT. 1.152 grm. gave 0.556 peroxide of iron corresponding to 33.45 per cent. iron. 111. 0549 grm. gave 0.266 peroxide of iron corresponding to 33-61 per cent. iron. Burned with chromate of lead,- I. 0-481 grm. gave 0.306 carbonic acid and 0.131 water corresponding to 17-3 per cent. carbon and 27.2 water. 11. 0*347 grm. gave 0*219 carbonic acid and 0*95 water correslwding to 17.7 per cent. carbon and 27.0 water. The following table shows the degree of approximation to the formula Fe Cy + 13Aq :- Calculated.Found. r I. 1.. 11. \ I1 I. Fe . . 136 = 339 33.2 33.4 33% c, . . N,; . a 72 = 17% 84 = 20.5 17.3 17.7 IJAq . 117 = 28.6 27.2 27OO Blue Conlpounds of Cyanogen and Iron. 139 It is evident from the quantity of water found that less hydrogen was in the substance than calculated and that t~ portion of peroxide of iron was contained in it. It is decomposed by potash in the same manner as Turn- bull’s blue which has been dried in the air; peroxide of iron is set free and hydroferrocyanic acid combines with the pot- ash as described under that compound. The cause of this reaction which seems irreconcileable with the composition 2Cfy3Fe lies in an oxidation of the iron taking place by the action of the air.We have seen above that Turnbull’s blue retains a considerable quantity of water and may assume that its elements are divided between the radical and the iron. Its formation is as follows :-2Cfy 3K} 3Fe0 = 2(Cfy H,) Fe30 + 3KO. 44 The fresh precipitate behaves as such a compound; but after it has been dried in the air potash separates from it pure peroxide of iron instead of the magnetic oxide. This proves that what indeed ensues with all protosalts of iron oxidation takes place on exposure to the air. A consideration of the analytical results immediately shows that such an admixture of peroxide of iron is contained in it. The process of oxida-tion consists in 2 atoms of the cyanide taking up 1 atom of oxygen 2(2(Cfy H,) Fe,O,} + 0 = 4(Cfy H,) + 3Fe,03.This formula expresses the elements contained in the sub- stance after drying in the air. A more probable expression for it8 cornposition is however obtained if the elements of three such compound atoms are arranged to 4 atoms of prussian blue and 1 atom peroxide of iron. An analogous compound to the pure unoxidated Turnbull’s blue is that which I de-scribed under the name of ferridcyanide of iron and potassium but which may as correctly be considered as a combination of 2 atoms hydroferrocyanic acid with 1peroxide of iron and 1 potash. A strong support of this view is the fact that it contains 4 atoms of water which are not expelled at 100’. I have also examined a great number of precipitates formed by ferrocyanide of potassium with other metallic salts and universally found that whatever may be the method of pre-cipitation it is not possible to replace all the potassium by the metal made use of.Ferrocyanide of potassium was added to a great excess of siilphnte of copper; the precipitate which had the wll-known red-brown colour was found after cop- plete washing to contain r? considerable quantity of potassium. The corresponding dirigy ycllow precipitate of ferridcyanide 140 Repwf. also contains potassium. On decomposing it by potash fer- ridcyanide of potassium and oxide of copper are obtained which proves that it is a true ferridcyanide and not analogous to Turnbull’s blue. The reducing action of light shows itself most strikingly in the case of this precipitate.It had after drying been kxpt in large pieces in a glass bottle which stood for some time near a window. All the outsides of the pieces turned towards the light became of a red-brown colour from the formation of ferrocyanide. On treating the ferrocyanide of copper above described with sulphuretted hydrogen no action at first seemed to take place; after some time however it commenced; and on the decomposition being completed a strongly acid solution was formed which became gradually blue on exposure to the air. It gave a blue precipitate with perchloride of iron but did not possess the characteristic reaction of hydroferrocyanic acid for it was not precipitated by aether.On adding mu-riatic acid this reaction however immediately appeared. By standing over sulphuric acid it dried into a blue rnms with a coppery lustre which with water formed a liquid not unlike ib solution. On analysis it gave to 0*487 peroxide of iron 0.262 sul-phate of potash. The formula 4Cfy {kH,requires 0.270 sulphate of potash to the quantity of iron found.

ISSN:0269-3127    

DOI:10.1039/MP8450300125

出版商:RSC    

年代:1845

数据来源: RSC

摘要:

March 30 1846.-Anniversary Meeting.-The President in the Chair. 'l'he following Report of the Council was read by the President and subsequeiitly ordered to be printed in the Society's Transac-tioiis :-Annual Report of the Council. N Calling the attention of the Members to the state of the 1 Society the Council have the satisfaction of stating that since the last Anniversary 20 Members have been admitted namely 18 ordinary Members and 2 Associates. The entire number on our list is 200; of whom 90 are resident and 95 non-resident 6 Foreign Members and 9 Associates ; making the income of the present year 2751. The disbursements have been less than usual and leave an increasing balance in the hands of the Treasurer. The arrangemcnt by which the Society is accommoclated with a room fbr meeting and a place for depositing its books and specirncns hy the Society of Arts still continucs to thc Heport.141 satisfaction we believe of both parties. It has been suggested that the Society of Arts would permit one of their officers to act in the capacity of Librarian to the Chemical Society. Such an accommodation would enable our members to receive books and journals at all times nnd render our collection much more available. During the last year the Society has lost by death four members,-Mr. Amos Swaysland of Crayford Messrs. John T. Cooper jun. Joseph Cooper and Mr. Thomas Everitt. Mr. Everitt received his chemical education in the labora- tory of the late Professor Stromeyer of Giittingen and after- wards entered upon the career of a public teacher of the sci- ence in London which he pursued with much ability till disqualified by serious illness.The last public appointments he held were the Professorships of Chemistry in the Medical School of lMiddlesex Hospital and in the College of Civil Engineers at Putney. Mr. Everitt lent his aid at the founda- tion of the Chemical Society and was an active member of its first Council. Although an unfrequent contributor to the scientific literature of his time Mr. Everitt was well known to us all as an accomplished analyst and to be much devoted to chemical inquiry. The Chemical Memoirs contain one communication by our lamented colleague *. Mr. Everitt did n6t outlive his forty-third year.Since last report the Society has published Parts 13 14 and 15 of their Memoirs and Proceedings which completed the second volume and also Part 16 of a new volume. The communications are twenty-nine in number several of them containing investigations of great extent and value and in-clude the researches of Messrs. Playfair and Joule on Atomic Volume and Specific Gravity ; Contributions to Actino-@he- mistry by Mr. Hunt; Researches on St,yrole and the pro- ducts of its Decomposition by Drs. Blyth and Hofmann; Contributions to the knowledge of Conjugate Compounds by Dr. Kolbe; an Account of Toluidine a New Organic Base by Drs. Muspratt and Hofmann; and Eiectrical In-quiries by Mr. J. Napier ; besides shorter communications of interest by Mr.Richardson Dr. Gregory (201. Yorke Mr. Warington Mr. Graham Drs. Tilley and Maclagan Mr. Crum Mr. De la Rue Mr. Williamson Professor Schiinbein Dr. Stenhouse Messrs. E. F. and J. E. Teschemacher and Professor Middleton of Agra. The audited report of the Treasurer was also submitted to the Society. * On the Leaf-stalks of Garden Rhubarb as a fioiirce of Malic Acid vol. i. p. 113.3. U AUDITORS’ REPORT. cp tQ Dr. ROBERTPORRETT (Treasurer),in Account with the Chemical Society of London. C‘r. -1845. 3 s. d. 1845. #2 8. d. March 29. To Balance from last Account ............... 337 14 4 May 19. By payment for Bookbinding ........................ 117 7 19. for Brass Stamp Ink and Dabbers i 100 1816. for a series of the Annales de March 25.To Subscriptions since received ............... 171 0 0 20. Chirnie,’ bought at public auction ............ 550 18. -for Rent to Society of Arts............ 25 0 0 / 18. of Gratuity to Servants and Door-110 0 1846. keeper ............................................. 1 Feb. 28. -for 24 Bottles With Ground Stoppers 190 March 12. for an Engraved Copper-plate 370 with Impressions therefrom ..................I- 25 * for Scientific Journals &c. English 16 8 0 and Foreign ....................................... I 25. -for Statimery Account-books, Postage Stamps Envelopes &c. ............... 110 9 1 25. of Poundage &c. to Collector ...... 972 25. By Balance to his Debit in new Account ......... 442 0 10 $508 14 4 S50B 14 4 London 25th March 1846.R.PORRETT, Treasurer. We have examined the above Account and find it correct PHILIPJ. CHABOT GEORGED.LONGSTAFF, } AudiitQrs4 Dr. Schcenbein on the Action of Hyponitric Acid. 143 The Society then proceeded to the election of Officers and Coun-cil for the ensuing year when the following Gentlemen were declared duly elected :-President.-Thomas Graham Esq. Vice-Presidents.-Arthur Aikin Esq. William Thomas Brande Esq. John Thomas Cooper Esq. Richard Phillips Esq. Treasurer.-Robert Porrett Esq. Secretaries.-Robert Warington Eeq. George Fownes Esq. Ph.D. Foreign Secretary .-E. F. Teschemacher Esq. Council,-Walter Crum Esq. ; Warren De la Rue Eeq. ; William Gregory M.D. ;Robert Hunt Esq. ; Sir Robert Kane M.D. ; H. B. Leeson M.D. ;William H. Pepys Esq. ; Lyon Playfair Esq. Ph.D. ; M. Scanlan Esq. ; John Stenhouse Esq. Ph.D. ; James Lowe Wheeler Esq. ; Lieut.-Col. Philip Yorke. The thanks of the Society were severally voted to the President Secretary Officers and Council for their services during the past year. Numerous interesting Chemical ob,jects were exhibited by the Members.

ISSN:0269-3127    

DOI:10.1039/MP8450300140

出版商:RSC    

年代:1845

数据来源: RSC

摘要:

Dr. Schcenbein on the Action of Hyponitric Acid. 143 April 6 1846.-The Presiclcnt in the Chair. Isaac Deck Esq. was elected a Member of the Society. The following papers were read :-CLXVI. On the Action of Hyponitric Acid upon Aqueous Solutions of Bromine und Chlorine. By Dr. C. F. SCHCEN-BEIN. THE hydrobromic and hydrochloric acids being decom- posed by nitric acid into water hyponitric acid and bromine or chlorine it appears little likely that by the com- bined action of bromine and hyponitric acid water will be decomposed and the hydrobromic and nitric acids formed. Such however seems to be the case as will be seen from the following statements. 1. If the fumes of hyponitric acid are made to pass into an aqueous solution of bromine the brown yellow colour of that fluid will be soon discharged and its odour of bromine as well as its bleaching power destroyed.The same solution on being mixed either with chlorine or peroxide of lead re- assumes its former colour bromine being eliminated under those circumstances. It is hardly necessary to add that an aqueous solution of bromine is also discoloured by nitric acid holding some hyponitric acid dissolved. Having added to aqueous bromine a sufficient quantity of hyponitric acid the liquid obtained contains no trace either of bromine or hyponitric acid and is in every respect like a mixture of 144 iMr. Schunck on tile dilute nitric ad hydrobromic acids. From the fkcts stated it appears that at the common temperature bromine and hyponitric acid on their being put in contact with water are transformed into hydrobromic and nitric acids and accord- ing to the theory of the day we must account for that reaction by admitting that water is decomposed under the circum- stances mentioned.2. A yellow aqueous solution of chlorine treated with hypo- nitric acid in the way indicated under #§ 1 loses its colour oclour and bleaching power and has exactly the same pro- perties enjoyed by a mixture of dilute hydrochloric and nitric acids. Hence it follows that hyponitric acid acts upon aque-ous chlorine in the same way as it does upon an aqueous solution of‘bromine. 3. If into a bottle having previously been charged with hydrochloric acid gas some strong and pure nitric acid is introduced the latter will even at a temperature of 15’ R.below zero be rapidly decomposed chlorine and hyponitric acid being eliminated and water formed. Adding to that mix- ture a sufficient quantity of water both chlorine and hypo-nitric acid will entirely disappear i. e. hydrochloric and nitric acid be reformed. From the facts above stated it follows,- G. ‘l’hat concentrated nitric and hydrochloric acids decom- pose each other into hyponitric acid chlorine and water even at very low temperatures. b. That a suflicient quantity of water being present chlo- rine or bromine conjointly with hyponitric acid decompose water (according to the theory of the day) forming nitric and hydrochloric or hydrobromic acid. c. That nitric and hydrochloric or hydrobromic acid being dissolved in a suficient quantity of water can at the common f emperaturc cocxist without decomposing each other.

ISSN:0269-3127    

DOI:10.1039/MP8450300143

出版商:RSC    

年代:1845

数据来源: RSC

摘要:

Mr. Schunck on tile 144 CLXVII. On the Szlbstances contained in the Roccella tinctoria. By EDWARD Esq. SCIIUNCK HE Roccellu tinctoria derives its interest from the fact of its being that species of lichen from which the finest kind of archil is prepared. It has been examined by Heereii and Kane. The former discovered in it a peculiar substance which he called Erythrin and a fat acid named by him Roc-cellic acid. The latter extracted from the plant a substance which he called Erytkrilin similar in properties to Heeren’s erythrin and a body to which he applied the name of Ery- Sabstances contained in the Hoccella tinctoria. 145 thrin but which possesses all the properties of the substance called by Heeren Pseuderythrin and supposed by him to be a product of the action of boiling alcohol on his erythrin.My results do not agree entirely with those of either of‘these chemists. The lichen which I employed for my investigation was ob-tained from Angola and Madagascar and was pronounced by a distinguished botanist to whom I submitted it to be the Roccella tinctoria var. fucvormis. In order to extract the various substances contained in it I submitted it to the fol- lowing operations :-The plant was cut into pieces and treated in a capacious vessel with boiling water. After the boiling had continued for some time the fluid which had acquired a yellowish-brown colour was strained through cloth. On cooling there was deposited from it a white substance in flocks and minute crystals.It was separated by filtration and washed with cold water. After drying it had a grayish appearance. In order to purify it it was only necessary to dissolve it in boiling al- cohol which left behind an inconsiderable black or brown resichie. On cooling it separated as a white crystalline mass. This substance resetnbles Heeren’s erythrin and Kane’s ery- thrilin. I shall call it Erythric acid. The fluid from which this substance had separated was of a light brown colour. On evaporation it became dark brown and muddy and left at length a dark brown viscid mass having a sweetish bitter taste. This mass after standing for 8ome time became solid and crystalline. It ras treated with cold water which left behind a crystalline substance of a brownish-white colour and a bitter taste.This substance is a product of the action of boiling water on erythric acid. I shall call it Picro-erythrin. In order to purify it it must be after washing it with a little cold water dissolved in boiling water to which is added some animal charcoal. After filtra- tion and evaporation there remains a yellowish mass which soon becomes crystalline and white. On treating this mass with cold water the picro-erythrin remains behind perfectly white and in a state of purity. To the brown fluid obtained by treating the dark brown mass with cold water a solution of sugar of lead was added which produced a copious grayish-brou-n precipitate. This precipitate after being separated by filtration and washed with water was decomposed by a stream of sulphuretted hy- drogen gas.A light yellow fluid was obtained which on evaporation became gradually brown and deposited a dark brown substance insoluble in water but soluble in alcohol Chem. SOC.Mem. VOL. III. L Mr. Schunck on the and alkalies. A brown viscid mass was left at last having an acid reaction and a strongly acid and at the same time bitter taste. It showed no trace of anything crystalline even after long standing. Jt was soluble in alcohol but insoluble in aether. Its aqueous solution was precipitated by a solution of glue by lime and baryta water and acetate of copper and was rendered muddy and gradually precipitated by sulphuric acid and common salt. It therefore consisted probably of some kind of tannic acid.Through the fluid separated from the precipitate produced by sugar of lead sulphuretted hy-drogen gas was passed until all the lead was precipitated. The filtered fluid gave a slight flocculent precipitate on the addition of alcohol but none with lime and baryta water,or sulphuric acid. On evaporation it left a clear brown syrup which soon changed into a crystalline mass having a sweetish bitter taste. It contained besides picro-erythrin to which it owed its bitter taste a quantity of orcin which was detected in the following manner:-A part of it was dissolved in boil- ing water and during the boiling a quantity of magnesia was introduced into it. After filtration the fluid was evaporated to dryness. It left a brown mass which no longer became crystalline on standing.The picro-erythrin had entered into combination with the magnesia and on treating the mass with aether in the cold a yelloxish-brown fluid m-as obtained which on evaporation gave crystals of' orcin recognisable by its well-known properties. The dark brown viscid mass obtained from the mother-liquor of the erythric acid left on being burnt a considerable quantity of ashes consisting of sulphate of soda chloride of sodium oxide of iron and carbonate of mag-nesia with a trace of carbonate of lime. The lichen after being extracted with boiling water had lost its grayish-white colour and become green. It was dried and then treated with boiling alcohol. The alcohol acquired during the process a dark emerald-green colour.It was strained through cloth while still hot. On becoming cold it deposited a green flocculent substance which was separated by filtration. The green colour of this substance could not be removed by washing with cold alcohol. On drying it be- came dark green and coherent but when powdered it was light green again. This substance is a kind of fat; it cannot be fused without being decomposed. When heated on plati- num foil it melts to a brown fluid giving off at the same time a strong smell of burning fat and burns without leaving any ashes. Heated in a tube closed at one end it melts andgives a brown oily sublimate which soon solidifies but without becoming crystalline. It is left behind on evaporating its al- *Substances coiztained in the Hoccella tinetoria.147 coholic solution as an amorphous green mass. It is precipi-tated from its solution in alcohol by water and also by an alcoholic solution of acetate of lead. It is insoluble in boiling milriatic and dilute sulphuric acids. Concentrated sulphuric acid dissolves it. Boiling nitric acid eLen if dilute destroys its green colour and makes it yellow. If treated with con- centrated nitric acid it is dissolved and decomposed with an evolution of nitrous acid; by degrees there collect on the surface of the fluid yellow oily drops which solidify on cool-ing. It is very little soluble in boiling caustic ley and inso- luble in ammonia. The dark green fluid from which this substance had separated was evaporated to dryness when it left a dark green viscid residue interspersed with yellowish crystalline grains.This residue was treated with boiling water which removed some picro-erythrin contained in it and then with cold alcohol which left behind a quantity of the greenish-white fat just described and acquired a dark green colour. The alcoholic fluid had an acid reaction. It contained roccellic acid and a dark green easily fusible fat. In order to separate the roccellic acid an alcoholic solution of sugar of lead was added. This produced a greenish-white flocculent precipitate which was separated by filtration and washed with alcohol. This precipitate consisting of roccel- late of lead was decomposed by dilute nitric acid which left the roccellic acid behind of a green colour.The latter after being washed with water to remove the nitrate of lead was dissolved in boiling alcohol to which some animal charcoal was added. After filtering the solution the roccellic acid se- parated on cooling in white crystalline needles. By adding water to the green alcoholic fluid from which the roccellate of lead had been precipitated it became milky and on boil- ing dark green drops of a fatty substance collected at the bottom This substance is a kind of fat which is easily fu-sible at the temperature of boiling water. Its green colour is no doubt owing to the presence of chlorophyll which cannot however be separated from it. It imparts no colour to boil-ing muriatic or dilute sulphuric acid. Boiling nitric acid de- stroys its green colour and changes it into yellow after which it dissolves in alcohol with a yellow colour.It is soluble in alkalies and is precipitated again by acids. The lichen after extraction with water and alcohol was treated with dilute caustic ley at a boiling heat. A dark brown fluid was obtained to which aftek filtration muriatic acid was added. This produced a dark brown flocculent precipitate which after filtering washing with water and drying appeared as a light brown powder. When heated it L2 Mr. Schunck on the burns without leaving any ash. On being treated with strong caustic potash at a boiling heat it gives off a slight smell of ammonia. It.is soluble in alkalies but insoluble in alcohol. The acid fluid. from which it was precipitated deposited on evaporation a dark brown substance in the same m7ay as a solution of tannin or extractive matter.It is doubtful indeed whether the brown substance precipitated by the acid from the alKaline fluid is contained in the plant as such or whether it is formed by the conjoint action of the air and alkali on some other substance in the lichen. The Roccella tinctoria is easily reduced to ashes. These ashes are grayish-white. They consist of sulphate of soda chloride of sodium oxide of iron alumina carbonate of lime and carbonate of magnesia. I shall now proceed to describe more fully several of the substances just mentioned. Erythric Acid. This body is the most important of those existing in the plant as it is that one which gives rise to the colouring matters for the production of which the lichen is employed.It is not possible however to obtain much from the plant since by the action both of boiling water and alcohol it undergoes a rapid change. By the method described above I obtained in one case from 1 lb. of the lichen 60 grains of it. If prepared without the intervention of alkalies erythric acid is perfectly white and tasteless. It is soluble in water alcohol and aether. 1 part dissolves in 240 parts of boiling water from which a great part separates on cooling in flocks or as a crystalline powder. Its solubility in aether distinguishes it from Heeren’s erythrin and its solubility in water from Kane’s erythrilin. Its solutions redden litmus paper. From a concentrated so-lution in boiling alcohol it is deposited on cooling in needles and star-shaped masses which consist of minute crystals.It is precipitated from its alcoholic solution by water as a jelly. If the alcoholic solution however be boiled for a length of time it is converted into erythric aether in the same way as lecanoric acid is converted by boiling alcohol into leca- noric aether; and if water be now added to the solution no precipitate is formed but the erythric aether gradually cry- stallizes in needles from the solution. By the continued action of boiling water erythric acid is converted into picro- erythrin. Heated on platinum foil it melts and burns away without leaving any residue heated in a tube closed at one end it gives an oily sublimate which after some time cry- stallizes ;this sublimate consists of orcin.Erythric acid is Substances contained in the Roccella tinctoria. 149 easily soluble in caustic and carbonated alkalies and in lime and baryta water and it is reprecipitated from these solutions by acids in form of a jelly unless they have previously been boiled or left to stand for a considerable time. If a solution of it in baryta water be boiled carbonate of baryta is deposited and acids now produce no precipitate of erythric acid. If the excess of baryta be removed by a stream of carbonic acid gas and the filtered solution be evaporated there are obtained prismatic crystals which are easily recog- nised as consisting of orcin by their intensely sweet taste by their being volatilizable without any residue by their solution precipitating basic acetate of lead reducing chloride of gold and giving a red colour with ammonia and red flocks on boiling with nitric acid.Erythric acid then like lecanoric is converted by alkalies into orcin and carbonic acid. A so-lution of erythric acid in ammonia exposed to the air soon becomes of a dark-red or purple colour. It is the basis and I believe the only one of the colouring matters derived from the plant. An alcoholic solution of erythric acid is not pre- cipitated by nitrate of silver but the addition of nitrate of silver to an ammoniacal solution produces a white precipitate which on boiling becomes black a mirror of silver being formed at the same time on the sides of the glass.Chloride of gold added to an alcoholic solution is not changed even 011 boiling. With perchloride of iron an alcoholic solution strikes a deep purple colour j on the addition of ammonia the colour is changed into yellow but the oxide of iron is not precipi- tated unless the fluid be boiled. It is not precipitated by an alcoholic solution of acetate of lead but ljasic acetate of lead produces immediately a copious precipitate. On combustion with oxide of copper the following results were obtained :-I. 05400 grm. dried at 212' gave 1-1640 carbonic acid and 0.2530 water. 11. 0.3640 grm. gave 0'7835 carbonic acid and 0*1820 water. These numbers lead to the following composition :-Calculated. I. I I. 34 equivs.Carbon . 2550'0 59.47 .58$'S 58*70 19 ... Hydrogen 2.375 5*53 5-20 5*55 15 ... Oxygen . 1500*0 35.00 36.02 35'75 4287'5 -0 1mO 100*00 The lead compound was prepared by precipitating an alco- holic solution of erythric acid with basic acetate of lead filtering washing the precipitate with cold water and drying in t'artio. 150 Mr. Schunck on tihe I. 0*6340grm. gave 0*6435carbonic acid and 0.1215 water. 0-3465 gave 0.0075 lead and 0.1970 oxide of lead. 11. 0-3195 grm. gave 0.3160 carbonic acid and 0*0630water. 0.4345 gave 0-0945 lead and 0*2520oxide of lead. This gives- Calculated. I. 11. 34 eqs. Carbon . . 2550*0 27-08 27-68 26-97 15 ... Hydrogen . 187.5 1.99 2.12 2'19 11 ... Oxygen . . 1100*0 11-69 11-04 11-72 4 ...Oxide of lead 5578-0 59.24 59-16 59'12 9415.5 100*00 lOO*QO 100-00 The decomposition of erythric acid by means of alkalies is therefore as follows :-1 equivalent of erythric acid . =C O, -2 equivalents of carbonic acid . =C 0, +3 equivalents of water . . . =H 0, gives 2 equivalents of crystallized orcin =C, H, O14. Erythric ather. This body has all the properties ascribed to pseuderythrin by Heeren and Kane and as I found its composition to differ very little from that given by Liebig for Heeren's pseudery-thrin and by Kane for his erythrin it can hardly be supposed that It is a different body. It is easily prepared by the ac- tion of boiling alcohol on erythric acid in the same way as lecaiioric Ether from lecanoric acid. Indeed its formation takes place so easily and rapidly in this way that it is almost impossible to extract erythric acid from the plant by means of boiling alcohol nothing being obtained by endeavouring to obtain it in this way but erythric Ether.In its appearance and properties erythric cether can hardly be distinguished from lecanoric Ether and as its composition in 100 parts happens to be almost the same the one may easily be mis- taken for the other. Erythric Ether is at first tasteless but after being kept for some time in the mouth it produces a burning sensation on the tongue. It is soluble in boiling water. If more of the substance be taken than the water can dissolve the excess melts forming drops like oil which sink to the bottom. On cooling the solution becomes milky, and a great part of the &her crystallizes out in needles and plates.It is easily soluble in alcohol and Ether. On allow- ing the alcoholic solution to evaporate spontaneously it is obtained in prismatic crystals. When heated in a tube it melts and is almost completely volatilized the vapour con- densing in the colder parts of the tube to a fluid which soon Substances coiitaiaed in the Roccella tinctoria. 1?I 1 crystallizes. It is soluble in caustic and carbonated alkalies and in lime and baryta water. From these solutions it is precipitated unchanged by acids unless they have previously been boiled for a length of time. It reduces nitrate of silver on the addition of ammonia and boiling and chloride of gold without the addition of any alkali.It gives a precipitate with basic acetate but none with neutral acetate of lead. On dissolving a quantity of it in caustic potash and subjecting the fluid to distillation I obtained in the receiver a fluid from which on the addition of dry carbonate of potash a thin layer of alcohol separated which was casily recognised by its peculiar spirituous smell and its burning with a blue flame. The fluid in the retort mas neutralizedwith sulphuric acid and evaporated to dryness. The residue was treated with alcohol which on evaporation gave crystals of orcin. Its products of decomposition with alkalies are therefore the same as those of lecaiioric zther. Its analysis gave the fol- lowing results :-1. 0*5380 grrn. gave 1.1965 carbonic acid and 0.2970 11-at er.11. 0-4085 grm. gave 0.9095 carbonic acid and 0-2260 water. These numbers correspond to the following composition :-Calculated. I. I I. 38 equivs. Carbon . 2850-0 61.45 60*65 60*72 23 ... Hydrogen 2875 6.19 6.13 6.14 15 ... Oxygen . 1500.0 32.36 33.22 35.14 4637'5 1mO 100*00 100.00 Its rational formula is C14.H, Old+C H 0. It is there- fore formed from erythric acid by the substitution of 1 equi-valent of oxide of ethyl for 1 equivalent of water. Piero-erythrin. This substance is a product derived from erythric acid. To it must be attributed the highly bitter taste of all the ex- tracts made of the lichen whether aqueous or alcoholic. In its properties however it agrees strictly neither with the erythrin-bitter of Heeren nor the amarythrin of Kane.It approaches nearest to the telerythrin of the latter according to the description given by him of that substance. It is a product of the action of water on erythric acid. If pure ery- thric acid as prepared by the process described above be treated with boiling water for a short time it dissolves the fluid acquires a bitter taste and on cooling deposits no ery-thric acid. On evaporation it leaves a brownish viscid mass leaving a taste between bitter and sweet. This mass after Mr. Schunck orb the some time becomes crystalline. It may then be treated with cold water which leaves the picro-erythrin behind white and pure. I have described above how it may be obtained as a secondary product in the preparation of erythric acid.In operating on the plant with boiling water much more is ob-tained of it than of erythric acid. On extracting the lichen also with boiling alcohol a considerable quantity is found in the extract. Picro-erythrin has the following properties. It has a strong but not disagreeably bitter taste. It is soluble in water alcohol and Ether. Its solubility in Ether distinguishes it from Kane's amarythrin and telerythrin which are insoluble in that fluid. It does not dissolve readily in cold water but easily in boiling water. Its solution in the latter however does not re-deposit it on cooling. On evaporating a solution of it in water or alcohol it is left behind as a white crystalline mass but never in well-defined crystals or needles.Its SO-lutions redden litmus paper slightly. It does not undergo any further change on being treated with boiling water nor does it form an Ether on being treated with boiling alcohol as erythric acid does; it has therefore little or no claim to be considered as an acid. Heated on platinum foil it melts to a yellow fluid is decomposed and burns with a bright flame leaving no ash. Heated in a tube closed at one end it gives a sublimate of orcin. It is decomposed by boiling nitric acid with an evolution of nitrous acid. Concentrated sulphuric acid dissolves it arid 011 boiling decomposes it with a disen- gagement of sulphurous acid. It dissolves in caustic alkalies arid in lime and baryta water in the cold. Its solution in baryta water deposits carbonate of baryta on boiling and the solution then contains nothing but orcin.Its solutions in alkalies speedily become red on exposure to the air. Its aque- ous solution is not precipitated by neutral acetate but copi- ously by basic acetate of lead. With perchloride of iron it gives a deep purple colour which is destroyed by ammonia the oxide of iron being immediately precipitated. Nitrate of' silver is not changed by it on boiling but on the addition of ammonia a precipitate is produced which on boiling the fluid is reduced the silver being deposited as a metallic mirror on the sides of the glass. Chloride of gold is slowly reduced by it on boiling the gold being depmited in the shape of' metallic scales; if caustic potash be added the reduction is effected instantaneously the gold being deposited as a black powder.It gives no precipitate with a solution of glue. Its analysis gave the following :-I. 0.5090 grm. gave 0*9530carbonic acid and 0-2850water. 11. 0,4690 grin. gave O*t;9tocarbonic acid and 02510 water. fhcbslances contained in the Roccella tinctoria. 153 These numbers give the following composition :-Calculated. I. Ir. 34 equivs. Carbon . . 2550 52.57 52'86 52-16 24 ... Hydrogen . 300 6.18 6.22 5*94 20 ... Oxygen . . 2000 41.25 40*92 41*90 4850 100*00 100*00 10000 The compound with oxide of lead prepared by precipita- tion with basic acetate of lead gave the following results :-0.2575 grm. gave 0-1465 carbonic acid and 0*0130water.0.3185 grm. gave 0*0220lead and 0.1960 oxide of lead. This corresponds to-Calculated. Found. 34 equivs. Carbon . . 2550 15-93 15.5 1 34 ... Hydrogen . 300 1.87 1.85 20 ... Oxygen . . 2000 12*51 13'70 8 ... Oxide of lead 11156 69-69 68.94 16006 1 -100*00 Erythric acid therefore in its conversion into picro-ery- thrin takes up the elements of 5 equiv. of water. Roccellic Acid. This acid was discovered by Heeren. If the lichen be ex- tracted with ammonia in the cold a yellow fluid is obtained which contains erythric acid and roccellic acid dissolved in ammonia. The roccellic acid may be separated by adding chloride of calcium to the fluid by which a precipitate of roc-cellate of' lime is produced or by precipitating the two acids with muriatic acid and treating the precipitate with boiling water which dissolves the erythric acid and leaves the roccellic acid behind.But by this method the acid is not obtained so pure as by extraction with alcohol as the ammonia takes up at the same time a brown substance from the plant from which it is afterwards difficult to separate the acid. I there-fore prefer the method which I have described above. Roccellic acid is a species of fat acid. I have nothing to correct in and little to add to the description given of it by Heeren. It is i~isoluble in water but easily soluble in alco- hol and &her. From a hot concentrated solution in alcohol it crystallizes on cooling in small needles forming when dry a white shining crystalline inass.By the spontaneous evapo- ration of its alcoholic solution it is obtained in larger and more defined crystals. Its solutions redden litmus paper strongly. Heated on platinum foil it melts to a transparent fluid which if' allowed to cool congeals again to a crystalline mass. If ftirther heated it is decomposed giving off a smell like burning fat and burns Liith R brignt flame leaving no residue. Heated in a tube closed at 9ne end it rnclts and 154 On Substances contained in the Roccella tinctoria. gives an oily sublimate leaving little or no residue; the oily sublimate is soon changed into a crystalline mass but on being again sublimed it remains fluid. Roccellic acid is insoluble in dilute mineral acids but soluble in alkalies. When oaustic potash is poured on it it swells up to a gela- tinous mass which is insoluble in the caustic ley but soluble in water.The solution on boiling foams like a solution of soap ; strong acids re-precipitate the roccellic acid in flocks. The so-lu tion on evaporation leaves a Crystalline saponaceous mass. Ammonia behaves in a similar manner. It is also soluble in carbonated alkalies carbonic acid being disengaged on boil- ing but it is insoluble in lime and baryta water. The solu-tion in ammonia gives with chloride of calcium and chloride of barium flocculent precipitates consisting of roccellate of' lime and baryta. A solution of roccellic acid in alcohol is pre- cipitated by an alcoholic sollition of acetate of lead but not by a solution of nitrate of silver A solution of it in ammonia gives with nitrate of silver a white gelatinous precipitate which becomes brown when the fluid is boiled but is not completely reduced.An alcoholic solution of roccellic acid does not reduce chloride of gold on boiling. On being ignited with oxide of copper- I. 0*42100grm gave 1*0200carbonic acid and 0.4025 water. 11. 0*2815grm. gave 0.6795 carbonic acid and 0-2720 water. From these numbers the following composition may be deduced :- Calculated. I. IT. 24 equivs. Carbon. . 23 ... Hydrogen 6 ... Oxygen . 1800*0 287.5 600*0 2- 66.97 10*69 22.34 100.00 66*07 65-83 10-62 10.73 23.31 23.44 100'00 100*00 The lead salt was prepared by dissolving the acid in a small quantity of ammonia and precipitating with acetate of lead.I. 0,4475 grm. gave 0.5530 carbonic acid and 0*2070water. 0-3405 grm. gave 0*0705 lead and 0*0990oxide of lead. TI. 0*4360grm. gave 0*5490carbonic acid and 0*2025 water. 09860grm. gave 0~07~0 lead and 0-0675 oxide of lead. These numbers correspond to the following composition :-Calculated. I. I I. 24 equivs. Carbon . . 1800 3355 33-70 54.34 22 ... Hydrogen . 275 5-12 5.13 5.1 6 5 ... Oxygen . . 500 9-34 9.81 9*42 2 ... Oxide oflead 2759 51.99 5196 51.08 5364 100-00 100°OO 100*00 This salt is therefore basic I have been prevented by want of material from examining the other salts of the acid.

ISSN:0269-3127    

DOI:10.1039/MP8450300144

出版商:RSC    

年代:1845

数据来源: RSC