摘要:

302 GLADSTONE ON RXCIPBOCAL DECOMPOSITION XLL-AdditioPaal Notes on Reciprocal Decomposition among Salts in Solution. By J. H. GLADSTONE, Ph.D. F.R.S. SINCEthe publication of my paper on Circumstances modifying the action of Chemical Affinity,”* and of “Some experiments illustrative of the reciprocal Decomposition of Salts,”t I have from time to time thought and experimented further upon the subject. The present communication is simply a gathering toge- ther of such observations as appear to me capable of throwing additional light on these laws of Combination. I reserve to some future occasion the experiments I have made on the time required to bring about a perfect state of equilibrium among various salts in solution as the results are not yet suf-ficiently matured for publication and the subject is a very distinct one.The ultimate dbpositioa of the varaow elements in soltdion is inde-pendent of the manmr in which they were originally combined. Suppose there be two basic elements M and M‘ and two salt-radicles R and R’; the question is whether if MR be added to Phil. Trans. 1855 179. t Chem. SOC. Qu. J. ix 144. AMONG SALTS IN SOLUTION. 303 M'Rin solution the same distribution of elements will take place as if MR were added to M'R'. From the law of reciprocal decom- position it follows as something like a corollary that it must be so and in my first paper I mas content with one quantitative experi- ment; yet as the opposite has been contended for I thought it well to test the law in other instances.The former experiment was this :-Two solutions were prepared the one containing equivalent proportions of sulphocy anide of potassium sulphate of potassium and ferric nitrate ; the other equivalent proportions of sulphocyanide of potassium nitrate of potassium and ferric sulphate. These two mixtures each con-taining the same absolute quantity of salts mere made up to the same volume with water; and the resulting colour was found to be identical leading to the inference that the ultimate distribution of the four salts in each solution was the same. The law was tested with a mixture of single equivalents of acetate of copper and nitrate of lead and a mixture of single equivalents of acetate of lead and nitrate of copper.Tlie colour was identical. A similar result was also obtained with siilphate of copper and nitrate of potassium as compared with nitrate of copper and sulphate of potassium. But it would rarely happen that a result perceptible to the eye could be obtained in this manner. The majority of metals that give colour to their compounds produce (unlike iron and copper) the same or nearly the same tint with whatever radicle they may be combined; and the same holds good with the colour-producing acids; whilst the great multitude of salts are colourless and there- fore invisible in solution. It occurred to me however that pey- ceptible reactions might be obtained with these also if mixtures were made of two colourless salts and then added to some coloured salt such as ferric sulphocyanide which is capable of reduction in colour by a redistribution of' its components.The amount of altera-tion in this third salt would of course depend on the proportion of all the four salts ready to act upon it; indeed the question would just be enlarged so as to include six elements instead of four -M MI and MI' with R R' and R". The experiment was tried in this manner :-Equivalent quantities of the sulpliate incl nitrate of potassium and the sulphate and nitrate of magnesium were dissolved in equal volumes of water ; a mixture was made of equal quantities of the solutions of sulphate of potassium and nitrate of magnesium and another mixture of equal 304! GLADSTONE ON ItECIPBOCLLL DECOMPOSITION quantities of the solutions of suIphate of magnesium and nitrate of potassium these were added to two equal portions of a solution of sulphocyanide of iron in the isoscope; and the diminution of the colour effected by them was observed.Now the sulphate of potassium is known to have a much greater power of reducing the sulphocyanide than the nitrate has but it was found that the two mixtures produced exactly the same tint. In like manner acetate of potassium with nitrate of lead pro-duced the same diminution of colour (within the limits of probable errors of experiment) a8 acetate of lead and nitrate of potassium. The same two mixtures were tried also on ferric meconate and gave a similar result The same experiment on the red sulphocyanide was also made with mixtures respectively of sulphate of copper with nitrate of of magnesium and sulphate of magnesium with nitrate of copper.The same shade was produced by each. A similar result was obtained with chloride of sodium mixed with sulphate of magnesium and sulphate of sodium mixed with chloride of magnesium. These two mixtures were also tried on the deep scarlet bromide of gold and they were found to produce an equal reduction of the colour. The two had the same effect likewise on a solution of the double iodide of platinum and potassium. Two solutions were prepared the one of the double sulphate of copper and potassium the other of an equivalent of sulphate of potassium mixed with an equivalent of sulphate of copper. They produced the same effect on a solution of ferric sulphocyanide.This experiment is of importance not because there was much doubt h priori that the condition of a double salt in solution is the same whether it has ever been crystallized or not but because at first sight some experiments recorded by Professor Graham seem to point to the opposite conclusion. He found in respect to the salt above mentioned and the sulphate of magnesium and potassium that the double salt was more diffusible than its mixed constituents.* Yet this seems to be the case only when the solutions are freshly prepared and in the cold and the discrepancy probably arises solely from the slowneas of the action by which uniformity is ultimately produced. When thcre are several salts with the possibility of solid matter forming the ultimate result may indeed be influenced by the order * Phil.Trans. 1850 22. AMONG BALTS IN SOLUTION. in which they are mixed Thus in the experiment above narrated with chloride of sodium and aulphate of magnesium compared with chloride of magnesium and sulphate of sodium it was only when the salts were mixed together beforehand that they equally reduced the iodide of platinum and potassium. When they were added one after the other to the red salt a deposit of platinum separated in the one case though not in the other. This however is not a real exception to the general rule which only refers to salts actually in solution. Ea?tension of M. Margueritte's experiment. M. Margueritte has shown,* by a number of instances that if a salt MR is less soluble in water than another salt M'R' or than MR' or M'R the addition of M'R causes a larger quantity of it to be dissolved.One instance is that of chlorate of potassium which is more soluble in a solution of chloride of sodium than in pure water. Now from the law of reciprocal decomposition (of which this is a result) it was foreseen that after a single equivalent of the more soluble salt M'R' had exerted its influence a second equiva- lent would produce an additional effect though to a smaller exient and so on. On trying the experiment this was found to be the case. 129 grm. of chlorate of potassium and 59 grm. of chloride of sodium were taken as equivalent proportions. Chlorate of Chloride of Water required Decrease for each equiv.Potassium. Sodium. for solution. of Chlor. Sodium. ~ 1 equiv. 0 2493 meas. 0 1 equiv. 2208 , 285 meas. JJ 1 9) 2 J 2060 , 1443 ,Y 1 > 4 9 1910 , 75 , If a compound MR is rendered more soluble by the presence of another compound M'R' the addition of either ME' or M'R will precipitate it from its saturated solution. This is also a necessary consequence of the law of reciprocal decomposition for the MR' or M'R will produce more MR and thc liquid is incapable of holding any more of this compound in solution. In a former paper I examined one particular case # Comptes rendus xxxviii 304. 306 GLADSTONE ON RECIPROCAL DECOMPOSITION of this general law namely when a salt insoluble in water dis-solves in an aqueous solution of an acid; and the law was found to hold good in every instance except one.That appa- rent exception was in the case of ferric phosphate dissolved in hydrochloric acid from which a precipitate was not obtained by the addition of phosphoric acid; but I have since found that phosphate of iron freshly prepared by double decomposition and well washed dissolves in phosphoric acid and thus the anomaly is fully explained. I have lately observed another apparent excep- tion in the case of phosphate of calcium dissolved in hydrochloric acid and this admits of another explanation for the tribasic phos- phate dissolves in three equivalents of the acid; therefore if on the addition of phosphoric acid any chloride of calcium be decom- posed the hydrochloric acid set free will suffice to dissolve the phosphate of calcium produced.But in all these cases the compound MR was a salt scarcely soluble in water and the more powerful solvent was an acid. Neither of these conditions is indispensable for the result. The following experiments will illustrate the general law in cases where lst the compound MR is soluble in water though not so soluble as M'R' M'R,or MR; and where M'R' is a neutral salt as well as MR. 1st-Sulphate of silver was dissolved in weak nitric acid; to a part of the solution nitrate of silver and to another part sulphuric acid was added with the production in each case of the crystalline sulphate. Again it was found that chloride of sodium had deposited from a solution of sulphate of sodium in hydrochloric acid ; the liquid which of course was saturated with the salt and contained likewise free hydrochloric and sulphuric acids and no doubt sulphate of sodium was divided into two portions and from each a crystalliza- tion of chloride of sodium was obtained by the addition respec- tively of sulphate of sodium and hydrochloric acid.2nd-Where the solvent is a neutral salt Chloride of lead was found to dissolv'e freely in acetate of sodium. Such a solution saturated with the chloride was prepared it was divided into two parts; to the one neutral acetate of lead arid to the other chloride of sodium was added and in each case after awhile chloride of lead separated. It appeam therefore that the more general expression of the law deduced from theory and given at the head of this section is AMONG SALTS IN SOLUTION.confirmed by experiment. Yet it is not to be expected that in every case the precipitate will actually make its appearance; for the formation of a double salt or the special solvent powers of the compound added may be a disturbing influence and may give rise to anomalous exceptions. Action of Acid Solvents and Recipeocal Decomposition in Alcohol instead of Water. When ferric phosphate was dissolved in hydrochloric acid the paleness of the solution and the increase of colour on the addition of more acid both rendered it evident to the eye that the whole of the iron was not in the state of chloride. Indeed a comparison of the colour gave ground for the belief that in a saturated solution at least as much as 85 per cent.of the iron is actually held dissolved as phosphate in the acid present.* It became interesting to see whether this solvent action would take place in the absence of water; and if so whether the same proportion between the different salts would be maintained. For this purpose a solution of hydrochloric acid in absolute alcohol was prepared and its power of dissolving dry ferric phosphate was tried. It dissolved a great deal assuming a pale yellowish-greeii colour. Thus one question was answered; but there still remained the inquiry whe-ther the proportions of the several salts in solution were the same as when the experiment was made in water.This received a reply in the negative showing that the nature of the liquid influenced the reciprocal action for a comparison of the aolution with one of ferric chloridein absolute alcohol showed that a very large quan- tity-probably 95 per cent.-of the iron must have been present as phosphate. Again the alcoholic solution became much darker when diluted with water which is not the case with the ferric chloride itself dissolved in alcohol. Another experiment made with this solution of the phosphate was the following :-a portion was divided into two equal parts; to the one was added some of the hydro- chloric acid dissolved in alcohol to the other the same bulk of pure alcohol. At first the two appeared of the same colour but after awhile that containing the large excess of hydrochloric wid became decidedly deeper.? See Chem.SOC. Qu. J. ix 162. f Some of the experiments described in thia and the preceding aection wem brought forward at the meeting of the Brithh Association at Lee& in 1868 bat the subject has been more fully worked out since. 808 GLADSTONE ON RECIPROCAL DECO~OSITION Testimony from Difluaion Experiments. I have already published* an account of an experiment showing that from a mixture of equivalent proportions of chlorideof sodium and nitrate of barium there diffused the four substances in such re-lative proportions as could only be explained on the assumption that each of the two acids had distributed itself between the two bases.* Professor G ra h am in his recent paper If On Liquid Diffusion applied to Analysis,” has described two experiments of a similar character j the one made with a mixture of chloride of potassium and sulphate of sodium the other with equivalent proportions of chloride of sodium and sulphate of potassium; but the results are not so conclusive in favour of the law of reciprocal decomposition for the numbers do not differ widely from such aa might be given if all the chlorine were in combination with the potassium and all the sulphuric acid with the sodium.Yet the accordance is not perfect and the distribution of the four elements may be very different. One thing is conclusively shown by the perfect accordance of the two experiments namely that in the words of Graham “The acids and bases are indifferently combined or that a mixture of chloride of potassium and sulphate of sodium is the same thing as a mixture of sulphate of potassium and chloride of sodium when the mixtures are in a state of solution.”$ A Method of Quantitative Determination by means of Circular Polarization.An argument in support of the law of reciprocal decomposition has already been drawu from an experiment made by Bouchardat,§ while examining the circular polarization of camphoric acid. He found that certain camphorates rotate the plane of polarization less than the acid itself and that when one of these salts was sbpersaturated with hydrochloric acid the solution did not exhi bit so much polarizing power as it would have done had the whole camphoric acid been set free.Unfortunately the experiment was not made with equivalent proportions of the different substances and hence it has no quantitative value. * British Association Report 1860 and Chem. News Ang. llth 1860. .). The relative proportions in the diffusate expremed in equivalenh were-mdium 1,253 chlorine 1,775 barium 812 nitric acid 692. $ Phil. Trans. 1861 197. 3 Comptes rendua xxviii 319. AMONG SALT8 I# BOLUTION. It occurred to me however that interesting numerical results might easily be obtained 'by taking advautage of the fact that different compounds of the same body rotate the plane of polha-tion differently; and just to test the possibility of this I have made some determinations with two substances belonging to very differeot groups-hicotine and tartaric acid.Nicotine gives a strong left-hand rotation but when combined with hydrochloric acid it entirely loses this power.* A solution of known strength gave a rotation of-14' it was mixed with an equivalent proportion of chloride of ammonium; the two odoura of nicotine and ammonia were perceptible in the mixture and when it was examined with the polariscope it indicated only -10.5. Hence it may be conduded that sufficient nicotine to produce the wanting -3 5" of rotation had entered into combination with hydrochloric acid displacing of course an equivalent amount of ammonia. These numbers happen to have the common divisor 3.5. The four substances must therefore have been present together in solution in very nearly if not exactly the following proportions Nic HC1+3NH4C1+NH +3Nic.(Nic=C,,H,N.) The experiment was repeated with chloride of sodium in place of chloride of ammonium. A rotation of -28O was reduced to that of -25" indicatihg the following composition for the mixture 3NicHCl+ 25 NaCl +3 NaO +25 Nic. As the nicotine has decomposed less chloride of sodium than chloride of ammonium and its absolute tendency to unite with the hydrochloric acid must have been the same in both expel+. ments it follows that the soda must have a greater tendency to combine with the hydrochloric acid than the ammonia has as compared with their tendency to remain in combination with water done. In combination with hydrochloric acid 3 equivalents of ammonia in fact balance themselves against the nicotine aJld 88 many as 8.3equivalents of soda are required to do the same.It is evident that the above experiment might be repeated with iunumerable other salts and tables of respective affinity might thus be drawn up. The method is also available for experimenting on the influence of the quantity of any of the constituents. Tartaric acid gave results which are not so easily understood. It has already been observed that equivalent proportions of the iaomorphous tartrates of potassium and ammonium have an equal * Indeed when the acid wa8 in great excess Wilhelmy'e observation of a alight indiation of right-handed polarization seemed to be confirmed. 810 GLADSTONE ON BECIPROCAL DECOMPOSITION influence on the polarized ray and the same appears to be true of the sodium-salt.The amount ofrotation i8 increased by the alkali and apparently independently of whether it exiats in the state of the neutral or acid-salt thus :-Tartaric acid .. .. .. .. = +loo , + 1 equivalent of sodium (bitart.) =+20.5 a + 2 equivalents , (neut. tart.)= +31* Tartaric acid was mixed with an amount of citrate of sodium sufficient to form the bi-tartrate of sodium if it should decompose it entirely. The polariscope showed that a partial decompo- sition had ensued. Additional portions of the citrate were added and an additional production of the tartrate resulted in each case. The numbers were- Tartaric acid .. .. .. =+lo" , + & citrate of sodium .. = +14.4 ,9 +1 >> ..= +18.5 > +fL J9 .. =+23* This result is in strict accordance with what was theoreticaIlg expected the sodium has distributed itself between the two acids in certain proportions; namely 8.5 to the tartaric and 12.5to the citrate when equivalent proportions were employed ; and when more citrate of sodium was added more tartrate was produced. Now citric and tartaric are analogous acids and perhaps the above is the true explanation of the phenomena observed; but when other salts of sodium mere employed results were obtained which showed some effect on the polarized ray that is not to be accounted for by such simple decompositions. Thus with acctste of sodium-Tartaric acid . . .. .. .. .. =+lo" YJ + 1 equivalent of acetate of soda = +22" I> >I +2 9 =+28" ¶> 9 +3 n = +31" When two or three equivalents of the acetate were employed the results obtained are intelligible enough but why should a single equivalent of acetate of sodium produce a greater increase of rotation than a proportionate amount of hydrate of soda would have done? But there axe greater anomalies still.When nitrate sulphate AMONG 8ALTS IN SOLUTION. or chloride of sodium or chloride of ammonium is added to tar-taric acid it actually reduces the rotating power. Thus :-0. 0. 0. Tartaric acid .. .. =+loo + 1 equiv. nitrate of sodium .. =+ 7" YY #Y + 2 equiv. , , .. =+ 5" + 2 equiv. sulphate of sodium. . = + 8O.5 YJ Y -+ 2 equiv. chloride of sodium..= + 3O.5 Y> + 2 equiv. chloride of ammonium =+ 4* With sulphate of ammonia a very slight increase of rotation was obtained.* The cause of these phenomena has not yet been ascertained. It evidently will interfere with the use of tartaric acid for the purpose intended ;but doubtless other substances besides nicotine might be found to give trustworthy indications.

ISSN:0368-1769    

DOI:10.1039/JS8621500302

出版商:RSC    

年代:1862

数据来源: RSC

摘要:

311 AMONG 8ALTS IN SOLUTION. XLK-On the general occurrence of Titanic Acid in Clays and the method employed to estimate it; on the Analysis of Iron Ores and Siliceow Miwakr containing Iron the separation of Oxide of Iron from Titank Acid and the methods of estimat-ing Iron. By EDWARD RILEY. SOMEtime since the author presented to the Society a short com- munication,? pointing out the presence of titanic acid in a series of Welsh fire-clays and at the same time proposed a new test for the metal. On a subsequent occasion also he pointed out in a verbal communication the errors that may arise from not carefully testing for the above acid which is present as will subsequently be shown in all clays,-or at any rate its absence is the exception. It is my object to bring before the Society not only the method adopted for deterrniuing titanic acid but at the same time to * Since the above waa written I have found that Biot has observed the remark- able changes in the rotation of the polarised ray by tartaric acid caueed by dilution or by combination with various other bodies.His experimenta throw no light on the question of reciprocal decomposition. =tQuarterly Journal of the Chemical Society vol. xii page 13. 312 RILEY OX TEE GENERAL OCCORRENCE OF enter minutely into the various methods of analysis usually adopted with silicates including also iron ores and to notice some of the points which have up to a recent period been to me very unsatisfactory; it must however at the same time be admitted that there are still many points which require investigation.Most chemists who have made the analyses of clays and mine-rals of a similar description will agree that when the analysis is conducted in the way ordinarily advocated many of the processea are very unsatisfactory. The general method adopted for the analysis of a clay is to take from 15 to 20 gms. and fuse it with an alkaline carbonate; the hsed mass is then dissolved in hydrochloric acid; the solution evaporated to dryness; the mass heated; and the silica sepa- rated by re-solution in hydrochloric acid ; the insoluble matter obtained. is regarded as silica without any further treatment or by some chemists it is either treated with a solution of hydro- fluoric acid or exposed to the vapour of that acid in Brunner’s apparatus.After the silica is entirely dissolved it is evaporated to dryness and ignited. Each of the last two methods is open to the objection that the pater portion of any titanic acid that may be present with the silica is converted into a fluoride of titanium which is volatile and consequently lost in the subeequent ignition. This may be considered to be one of the reasons why titanic acid has not been found by chemists in all clays although generally speaking a shall residue is left when the silica from an analysis is heated as above and the titanic acid may be detected with the blowpipe. This residue also contains traces of alumina. Proceeding with the analysis and precipitating by ammonia and well washing the precipitate it is dissolved by hydrochloric acid (0 the filter) and treated with a solution of pure caustic pot&.In this process it will be observed that when the quantity ofiron is small instead of obtaining the ordinary and charac- tenstic precipitate of peroxide of iron a precipitate is obtained of a much lighter colour and evidently a very impure peroxide of imn M) impure that the author haa alwaye found it neCesMLry to iglnitc the wsclhd and dried precipitate of iron and alumina and redissolve it in acid which proceas serves to separate a certain amount of silica which is always left in solution after the eva- p&ion to dryness and may be eeparated thus or by a second evaporation to dryness as shown in subsequent experiments.After separation of the eilioa by either of the two methods -men- TITANIC ACfD IN CLAYS ETC. 313 tioned a much more satisfactory separation of the iron and alu- mina may be made by potash. The oxide of iron after separation is dissolved in hydrochloric acid and reprecipitated by ammonia ; it is then generally weighed and considered to be pure peroxide of iron; but it very rarely dissolves completely in hydrochloric acid sometimes leaving a residue which retains the form of the oxide; sometimes but more rarely separating gelatinous silica. This residue on being crushed forms a powder which defies filtration and in most of these cases consists of titanic acid. This has been found to take place more particularly in the analyses of clays and blast-furnace cinders or slags.The following are the analyses of the blast-furnace cinders from the Dowlais iron. works showing the average composition of the cinder for a week’s working. The cinders were taken as follows cinder was taken from each furnace every day and portions of the cinders finely pulverised 200 grains of each being weighed out daily and kept separate in a bottle labelled with the number of the furnace. At the end of the week the pulrerised cinder in each bottle was again intimately mixed and analysed. The Table gives the result,-the numbers at the top being the numbers of the furnaces in blast at the time ; column ‘‘average of -13 furnaces,” gives the analyses of a mixture of equal weights of pul-verised cinder taken from each furnace at different times on one day.In all the above analyses the iron could not be obtained very pure the impurity most probably consisting of a small quantity of titanic acid. The iron given in the analyses of blast-furnace cinders is generally too high. In many cases no rnanganeae is given and unless great care is taken it is very difficult to obtain the oxide of iron even in a tolerable state of purity. These analyses are thought to be of sufficieut interest to insert in the paper as they are most probably the most extensive series of analyses of blast-furnace cinders yet made. Average composition of BLAST-FUBNAOECINDEB (sLAa)'da.ringa week'8working of the Furnaces. f Average 1 3 4 6 9 10 11 12 13 14 15 16 18 Mean. of 13 Fumacea E r M 4 silica ... .. . .......... 39.09 42'52 41.30 44.88 42.08 43.68 42.45 41.08 46.23 42.51 40.02 40.69 38-48 41-85 43.07 Alumina .,. . ....... . I. 17.14 14'96 16.21 15.61 14.19 16.25 14'30 13.65 11.55 13'12 14.71 14-82 15.13 14.73 14.85 Protoxide of Iron ...... 2-0.7 8.62 2.65 6.91 2'36 1.33 2'04 1.29 3.08 3.48 2-52 2.19 0.76 2'63 2.63 Protoxide of Manganese 1.16 1-60 1.10 1'67 1-69 1'15 1.22 1.02 1'02 1'18 0.91 1-04 1.62 1.24 1.37 Lime . . ...... . . ...... 31'96 30'04 30'55 23-81 81-65 28'57 30.89 34-32 32'09 31.35 32.27 32'60 32.82 30.99 28.92 Magnesia.. ...... . . .... 4.31 8-95 4.42 4.38 4.67 4.42 5.32 4'66 3-78 4-42 6.47 4.63 7.44 4.76 6.87 Potash.. ........ . ... . . 1.98 2.08 2.26 1.98 1-73 2.21 2.04 1.75 1'53 1.79 1.72 1.71 1.92 1 *90 1.84 Calcium ...... . .,... . . 1'64 0'85 1-20 0'59 1-87 1.29 1.04 1'22 1.04 0.89 1 31 1.29 1-25 1.15 1.01 Sulphur ... . .......... 1-31 0.68 0.96 0.47 1'10 i.04 0 83 0'98 0.83 0.71 1.05 1.03 0.99 0.92 0.89 Phosphoric Acid .,. . .. -22 0.41 0'13 0.43 0'10 0'10 0.17 0.26 0-15 0'16 tracee. -_--_._--.-------0 100-86100.59 100 *78100-68100.68 100 '04 100.23 99 *g6100.16 99 '70100 *23 100 :OO 100.64 100.32 100 '36 4 _I-___-__._------_--__. Metallic Iron . . . ... . . . 1.61 2.81 2.06 6-37 1.81 1.03 1.58 1'08 2.39 2.10 1.96 1.70 0.67 2'04 1 97 Fnrnacee 1 to 16 Common White Forge-pig. 18 Furnace on Foundry-pig. TITANIC ACID IN CLAYS ETC. Should the mineral also contain phosphoric acid a podion of that acid is invariably lcft with the oxide of iron although by far thc larger portion is found in solution with the alumina.The alumina is separatcd by acidifying thc solution and boiling with chlorate of potash to destroy any orgaiiic mattcr then precipitated by carboiiate of ammonia; the phosphoric acid may be sepa- rated aftcr tlie alumina has becn weighed by dissolving in hydm-chloric acid adding tartaric acid ammonia chloride of ammonium and a niagiicsian salt. It is rare that clays contain an appreciable amount of man-ganese ; any that they may contain will be partly prccipitated with thc iron arid alumina; this is oiic oftlie many objections to the prccipitatioti by ammonia. The lime is then scparatcd by osalate of ammoiiia arid wciglicd either as carbonatc or sulphate ; this dcter- minatioii appears to be quite satisfactory.Tlie magnesia is next prccipitatcd by ammonia and pliospliatc of soda. In clays this modc of prccipitation is oftcn very unsatisfactory the precipitate being quitc flocculent instcad of exhibiting the characteristic crystalliiic nppcarance of the animonio-magnesian phosphate. This may bc duc in somc CASCS to a littlc alumina held in solu- tion by tlic largc exccss of ammonia used to precipitate the osidc of iron arid alumina but there is rcason to think that it ariscs also from otlicr causcs which it must be admittcd have not yct rccvivcd sufficient attcrition to ciiablc one to speak posi- tively rcspecting tlicm. Having Iiricfly skctchcd the ordinary method employed for analysing clays kc.,I shall procectl to describc some experiments madc in relation more particularly to the estimation and separa-tion of titanic acid. First in trcating the silica with hydrofluoric acid to prevent the fluoridc of titanium from volatilizing sulphuric acid should be used; by tliis mcans tlie mholc of thc titanic acid with the silica may be obtaiiicd. It it howcvcr invariably mixed with alumina and miiiutc traces of iron as will bc scen by the experiments dctailed. More titanic acid may he scparatcd liy again evaporating to dryness thc- filtrate from the silica heating it strongly redissolv- ing in acid arid scpr:iting irisoln1)le matter whicl~ comsists of a misture of titanic acid and silica with traccs of alumina. Thc results of numerous cxperiments lead me to the conclusion that thc highcr thc temperature to which the fused mass is heated 316 RILEY ON THE GENERAL OCCURRENCE OF after solution and evaporation to dryness the greater will be the quantity of titanic acid left with the silica in the insoluble state and therefore the smaller will be the quantity obtained in the second evaporation.The oxide of iron obtained in the way just described in the analysis of clays was tested as follows for titanic acid :-After it had been ignited and weighed it was dissolved in hydrochloric acid and insoluble matter was separated. This was burnt and treated in a platinum crucible with hydrofluoric and sulphuric acid and the filtrate was reduced with a solution of sulphate of soda added in large excess sufficient to neutraliae all the free hydrochloric acid.The solution was then boiled and when nearly the whole of the sulphurous acid was expelled a white precipitate was formed. The boiling was continued until a slight indication of sesquioxide of iron was seen ; the liquid was then rapidly -filtered; the filter which was not washed was transferred wet into the platinum crucible containing the residue left on treating the mixture of silica and sesquioxide of iron with hydrofluoric acid,-then dried and burnt carefully at a low temperature; and the burnt mass waa fused with bisulphate of potash dissolved in cold water and boiled after perfect solution. Immediately on boiling a precipitate was formed which on filtering and testing gave all the distinct reactions of titanic acid.The following are the results obtained from,the analysis of a Welsh fire-brick :-Some considerable portion of the brick was pounded up ; and a small portion was reduced to very fine powder 19*23grns. of which after ignition was taken for analysis. It was fused over a Bunsen's burner with 6 or 7 times its weight of pure carbonate of soda dissolved in hydrochloric acid evaporated to dryness and carefully heated. The silica was separated by solution in hydro- chloric acid and dilution with water. The silica obtained weighed 12.09 grns. Silica treated with hydrofluoric and sulphuric acids evaporated to dryness and ignited left residue *22,5. This residue was fused with bisulphate of potash and dissolved in cold water and the liquid after complete solution was boiled.After boiling some time a distinct precipitate was formed but hardly sufficient to weigh. The solution precipitated by ammonia yielded a pre- cipitate of alumina containing a trace of iron which weighed 0.21 grn. The filtrate from the silica was evaporated to dryness and heated ;the residue dissolved as before in hydrochloric acid and the insoluble residue separated it weighed 0.36 grn. This TITANIC ACID IN CLAYS ETC. residue treated with hydrofluoric and sulphwic acids evaporated to dryneas and ignited left residue = 0.16 grn. Tbia residue was fuaed with bkrulphate of potash and dissolved in cold water and the liquid after sohtion waa boiled ;immediately on boiling a pre- cipitate formed which was boiled for some time allowed to stand for a night in a warm place then collected on a filter waslied with water containing eulphuric acid and weighed 0.105 grn.and this gave with microcosmic salt the characteristic reaction of titanic acid. The filtrate from the titanic acid was precipitated by ammonia and gavea Precipitate of alumina which weighed -075grn. considered as A1,0,. The filtrate from the second evaporation for alumina and aesquioxide of iron was made nearly neutral with ammonia and a moderate quantity of acetate of soda was added; the eolution well boiled and the basic acetate8 of iron and alumina were collected and washed a few drops of -acetate of soda being added at each washing; the precipitate was dissolved in hydrochloric acid and precipitated by ammonia then washed dried ignited and weighed its weight was 6.16 grns.This was dissolved in hydrochloric acid a flat-headed glass stirrer being used to crush the lumps. After complete solution a residue of dica weighing 0.04 grn. was left. and separated; the solution of sesquioxide of ironand alumina in hydrochloric acid was treated with pure potash in a platinum dish; and after boiling the sesqui-oxide of iron was separated by filtration. The sesquioxideof iron after re-solution and precipitation by am-monia was ignited and weighed its weight was -675 grn. This was dissolved in hydrochloric acid a residue retaining the shape of the pieces of oxide of iron and coloured with it then remaining; these lumps were crushed and the boiling was continued until the residue was perfectly white ; it was however so smdl in quantity that no weight could be obtained for it on burning the filter.The filtrate was treatedmith biaulphite of soda in sufficient quantity to neutralize the whole of the free hydrochloric acid; it was then boiled till sulphurous acid could only just be smelt. After application of heat a precipitate soon formed which gradually increased. When this precipitate began to assume a yellow tiirt from oxide of iron it was rapidly filtered and the filter without being washed was thrown into a platinum crucible dried and burnt then fused with bisulphate of potash. After fusion the mass was dissolved in cold water and theu boiled. After boiling some time a precipitate was formed which was allowed to stand a night then filtered and 318 RILEY ON THE GENERAL OCCURRENCE OF wcighed RS before described ;the weight obtained was *095grn.The filtrate from the oxide of iron after treatment with potash re-solu- tion in hydrochloric acid and re-precipitation by ammonia wm evaporated to a small bulk and after treating with ammonia and phosphate of soda gave indications of the presence of magnesia; 2Mg0.PO5 obtained = 0.12gr. To separate alumina the filtrate from oxide of iron was acidified with hydrochloric acid chlorate of potash was added the solution well boiled and the alumina precipitated by ammonia and carbonate of ammonia washed dried ignited and weighed. Its weight was 5.535 grns.On dissolving it in hydrochloric acid a similar quantity of silica was left = 0.03 grn. The filtrate treated with tartaric acid magnesian salt ammonia and chloride of ammonium gave after standing a night a few distinct crystals of ammonio-magnesian phosphate shewing the presence of a trace of phosphoric acid. The lime and magnesia were separated by the usual methods; with the magnesia there was a very small amount of the flocculent matter already alluded to. The lime weighed as gulphate gave 0.285 grn. The ammonio-magnesian phosphates weighed 0.56 grn. The alkalies were determined by boiling the finely levigated brick with strong hydrofluoric acid in a gold crucible. 57-55 grns. taken after the brick had been thoroughly decomposed was evaporated to dryness with sulphuric acid in a platinum dish; the mass after being strongly heated was well boiled in water the lumps being crushed with a flat-headed glass rod; and the whole was trans- ferred into a large beaker without filtration and precipitated by ammonia and carbonate of ammonia.This method is adopted on account of the difficulty frequently experienced in separating the matter left insduble in the boiling water the fine particles usually clogging the filter. After separation of the precipitate by ammonia and carbonate of ammonia the filtrate is evaporated to dryness and ammoniacd salts volatilized ;the residue is then treated with sulphuric acid and again evaporated to dryness to drive off excess of sulphuric acid then dissolved in water treated with a solution of baryta in excess and filtered.The usual method given is to treat with acetate of baryta but it has always been found almost impossible to separate the sulphate of haryta by filtration as it passes through the filter and filtersvery slowly ;the use of hydrate of baryta entirely obviates this difficulty. The filtrate is acidified with acetic acid evaporated to dryness and ignited; the carbonate of baryta and charcoal are separated by filtration ;the carbonates TITANIC ACID IN CLAYS ETC. of the alkalies are dissolved in water ;the solution is acidified with hydrochloric acid and the alkalies weighed as chlorides the chlo- rides obtained weighed 2.09 grns. The above method has alwaye been found to yield most satisfactory results and is moreover exyedi tious.The potash and soda were Separated in the usual way with bichloride of platinum and 5-78 grns. platinum salt obtained. Silica. Silica by first evaporation . 12-09 0 A1,0 with silica separated by HFl . 0.21 . 11.88 S&ca by second evaporation 0.36 0 TiO separated by HFl . . . 0-16 . 0.20 0 Silica with iron and alumina . 0.04 . OM 12.12 Brick Silica 1923 12.12 100 63.02 Silica 63*02% Titanic Add. Titanic acid from silica second evaporation . 0.105 Titanic acid from Fe,O . . . . 0.095 0.200 Brick Titanic acid Titanic acid . 1*04 19*23 . *zoo : 100 Titanic acid 1.04% Alumina. Aluminawith silica . . . . 021 0 Aluminawith titanic acid . . . . 0.075 Alumina separated from iron .5.535 *Less silica with alumina 0030 5.505 5.505 5-790 Tbie silica is not calculated as coming fromthe brick :it ia thought to be due to the action of ptash on the glase used. 320 RILEY ON THE GENERAL OCCURBENCE OF Brick Alumina Alumina 0. 19-23 5.79 .. 100 : 80.11 Alumina 30.11% Sesquioxide of Iron. Magnesia with oxide of iron weighed as 2MgO.PO50*12 2MgO.PO 2Mg0 2Mg0.P05 MgO 113.34 41-34 : 0.12 0.043 Titanic acid with iron . . . . 0.095 >J . * . 0.048 Magnesia 0.138 FC203 0.675 -0*138*= 0.537 Brick FCA FCP 19-23 0.537 .. 100 2.79 Lime. CaO.SO CaO CaO.SO 68 28' 285 0'11735 If 19.23 0.11735 : 100 0.61 Lime 0*610/ Magnesia. 2Mg0.P05 from Fe203 .0.120 2Mg0.P05 from CaO. . 0.565 0.685 2 MgO.PO 2Mg0 2Mg0.P05 MgO 113.34 41.34 : 685 0.2498 Brick MgO MgO If 19.23 0.2498 : 100 1-29 Magnesia 1*29% Alkalies. KC1.PlCI KO KCLPICI KO 244.2 47 : 5.73 1*1028 TITANIC ACID IN CLAYS ETC. Brick KO KO 57-55 1*1028 100 1*92 KO KC1 KO KCI 47 74.5 101028 1.748 Mixed chlorides KC1 NaCl 2.09 -1.748 = 0.342 NaCl NaO NaCl NaO 58% 31 0.342 0.1812 Brick NaO NaO 57.55 0.1822 100 0-31 Tabulated Results. Silica . . . . 63-02 Titanic acid . . . 1-04 Alumina . . . . 30.11 Sesquioxide of iron . 2.79 Lime . . 0.61 Magnesia . I *29 Soda . 0.31 Potash . 1.92 0 Phosphoric acid traces . 101.09 clo DETERMINATION OF SILICA AND TITANIC ACID IN FIRE BRICKS.M Bri& in $ne powder ignited befoe Fh. First Evaporation. Second Evaporation. Brick Silica Titania Reeidue from Titanic Jumina Titanic Silica by taken Acid Dewription of Brick Silica ydroiluoric an1 Acid in in Insoluble Acid in er cent. Oms. ercent. snlphuric acid. Residue Raidue Reeidue Residue 0 ---7--x H 1 36 *976 66.11 1 -06 Stoazbridge (Hickman) 23 -816 0 -81 0 :265 0 -69 0 *545 0 -125 m 2 20 -90 65 +42 1 -06 do. (Rdord) 13.88 o 856 0.120 0 -330 0 *loo Alumina w Q 3 28 -59 60 -49 0 -60 Newcastle (Lucas) 17 -49 0 -636 0 .17 0 -40 0 *436 0.165 4 27 *ll 60 -60 0 *42 Newcaetle (Stephenson) 16 *'66 0 -470 0'116 0 -316 0 -61 4 E 0 *32 O.I7O 6 22 *146 56 *86 0 *67 do..(Rammy) 12 -49 o .a65 6 21 *965 62 *90 0 -9s Wortley,Lecde (Ingham] 14.03 0 -475 0 -16 0-335 0 -375 0 -06 8 7 23 *31 62 -39 0.69 Harwarden Northffaler 14 ~665 0 -82 0 -03 0.225 0 *475 0.13 d d $8 26 *92 64 '52 0 *60 Yellow London Clay 17.64 0,405 t 0 *276 t 9 28 -89 91 *84 trace Ewe11 Brick Surrey 26 -98 0 '210 10 21 -70 94 33 trace DinasBrick,&uthWaler 20 *a7 0 *635 0 -236 11 23 -48 75 -16 trace Black Alder Devonahire 17 34 0.296 I[ 0 '306 } p - e In 6 the residua from evaporation 1 and 2 were weighed together fused with biaulphate of potash dissolved in cold water and eilica mpamted Silica = 0.246 ; titanic acid = 0.16. I-In 8 the aame method adopted aa in No.6 ;dlica obtsined ==O ,246 titsnic acid = 0'135 alumins = 0'206. $ Clay dried at 800° Fahrenheit TABLE showing the results of various analyses in which Titanic Acid was found but not determined except in No.2. The Titanic Acid was not in this analysis detemincd by fusion with bisulphate of potash and precipitation by boiling and is a little too high. In analyses 4 5 6 and 7 no indication of Titanic Acid wag obtained when treating the soils by the ordinary methods ; but special examination of the Sesquioxide of Iron obtained in the analysis revealed ita presence ;and moreover it wu found that the soils contained Iserine which was readily separated with a magnet. 1 2 3 4 6 6 7 Silica ,. .. .. .. 69 *21 2c76 65 *16 48*$3 49 *17 47 0 *10 48 *01 2.19 1. American kaolin Titanic acid .. .. .. 2. Bastard ironstone Alumina .... *. 27.77 17 *02 21.88 18*77 18.86 18 -23 19 el3 technically known ai FeO ‘(Jack” 3. Blue clay from Wilt- Peroxide of iron .. .. 8 34 10-80 T7 shire Magnetic oxide of iron .. .. .. 9-68 9077-10 -81 9 *31 4,6 6 and 7. Soilsfrom Manganese (red oxide) .. ih2 0.65 0*65 0 *76 0 -49 the West Jndia is-Lime .. .. .. .. i.41 26.11 g.62 8-03 8 -30 8 *26 7*59 lande Magneeia .. .. .. 0.41 11 ‘84 1 *51 4 -62 4-11 5 -38 4.03 Potaeh .. .. .. .. 1.91 0.39 2 *22 0.27 0 *29 0*20 0 *30 traces of Soda .. .. .. .. with Lithia .. .. 1*82 2 -08 1 *82 2 -06 Phosphoric acid . . .. .. 3 *86 .. trace Sulphuric Carbonic acid acid Sulphate of lime . .. .. 0-61 2 *40 0 *20 0 *12 0 *20 0 -20 Sulphur Combined water .. .. 6 -87 0.14 6 -04 3 -33 8 .I2 8*24 8 086 Moisture .... 0*24 0*15 3 *24 2.36 2 ‘49 4 *20 4. Organic matter .. *. .. .. y.67 1 *16 1 -68 1-63 1-90 100 -16 99 *98 99 -40 100 -10 100*39 100 el1 101 -07 # Titanic acid waa detected in very appreciable quantity but not determined. 884 RILEY ON THE OENQ1BALOCC-CE OF Table I shows the amount of titanic acid found in ten samples of Are-bricks and in a sample of ordinary London clay. The titanic acid was determined in the way already detailed; viz. evaporating the filtrate from silica to dryness and heating. The method employed is perhaps not very accurate as most probably in all cases the whole of the titanic acid is not separated even by two evaporations to dryness as will be seen by referring to the detailed analyses some was found with the iron.It however shows the general occurrenoe of this acid in clays; in many the amount certainly exceeds one per cent. It will be observed that in columns 3 and 4 the whole of the titanic acid is with the silica; in some cases it has been obtained entirely in the second evapora- tion. This appears to be due to the temperature to which the fused mass is heated after solution and evaporation to dryness. The higher the temperature the greater is the qiuantity of titanic acid obtained with the silica and vice versii. Professor Miller of King's College London has found 1.25per cent. of titanic acid in Stourbridge clay and Mr. D. Campbell has found it in several clays by adopting the method above detailed. The last three bricks are essentially silica bricks and contain no clay.Practical men have informed me that the last brick is of inferior quality. In these experiments my evaporating dishes were coated on the interior with the peculiar metallic lustrous stain which so per-tinaciously sticks to all vessels in which a titanate is dissolved in 811 acid or precipitated by boiling. Preparation of pure Titanic Acid. Pure titanic acid was prepared from the red nitride crystals from an old blast-furnace hearth ; it was obtained unintentionally. The crystals after having been freed as far as possible from iron by means first of dilute sulphuric acid then of strong hydrochloric acids were heated with a mixture of nitric and hydrochloric acids the consequence was that some considerable portion of the crystals was oxidized.The titanic acid was separated from the crystals by decantation then washed and fused with bisulphate of potash and thrown down from the solution of the fused maw by boiling. The washing of this precipitate ww interminable and the sulphuric acid could not be completely washed out. On drying it and igniting some sulphuric acid was driven off and on treating TITANIC ACID IN CLAYS ETC. the ignited residue with water no sulphuric acid was detected. From the above it would appear there is a difficultly soluble com- pound of sulphuric and titanic acid which is continually washed out from the acid; and this is most probably the reason why the determinatiou of titanic acid by precipitation from a boiling solu- tion is not accurate.Special Experiments with Titanic Add. 2.78 grns. pure titanic acid were treated with hydrofluoric acid and some sulphuric acid was added; the whole was em- porated to dryness ignited and weighed. Weight obtained 2.76 grns. It was then fiised with bisulphate of potash thg fused mass dissolved in cold water the solution boiled and the titanic acid separated with the usual precautions. The titanic aeid thus obtained weighed 2.535 gms. The filtrate precipitated with am- monia yielded a further quantity of titanic acid weighing 0.12 thus showing that the precipitation by boiling is not quite com-plete but nearly so. Experiments with Titanic Acid and Alumina. Some pure alumina was prepared from alum by precipitating with ammonia washing the precipitate drying and igniting re-dis- solving in hydrochloric acid and separating insoluble matter (a little silica) then re-precipitating by ammonia wmhing drying and igniting.Alumina *22 and titanic acid -08 were fused together with biaulphate of potash the fused mass was dissolved in cold water and the solution boiled. The titanic acid did not precipitate immediately but in five or ten minutes; the alumina did not appear to affect the precipitation of the titanic acid. No. 2. Experiments were made with 0.2 and 0.3gm. of titanic acid with some alumina the acid could always be detected and alumina had no influence whatever on its precipitation. In fusing alumina with bisulphate of potash care should be taken not to heat the mass too strongly and drive off too much sulphuric acid as in that case the fused mass becomes difficultly sohible in water and in some cases after solution the alumina may possibly be precipitated by boiling from insufficiency of sul- 326 RILEY ON THE GENEBAL OCCURRENCE OF phuric acid.The precipitate caunot however be mistaken for titanic acid and may be readily taken up by adding b little dilute sulphuric acid. No. 3. Quantitative experiment. 1.135 alumina and 0.40titanic acid were fused together with bisulphate of potash; the mass was dissolved in cold water the solution boiled for some hours and the titanic acid separated as usual TiO obtaiued =0.325. The alumina was precipitated from the filtrate wit.h ammonia and carbonate of ammonia the liquid filtered the precipitate washed once or twice redissolved iu HC1 and re-precipitated.The quantity of alumina obtained was 1.185-TiO .. .. *. .. 0.325 A1,03 .. .* .a .. 1.185 1.510 thus showing a loss on the titanic acid and a gain on the alumina as might be anticipated from previous experiments. Experiments with Titanic Acid and Sesquioxide of Iron. Pure sesquioxide of iron was obtained from protosulphate which had been recrystallised three times from distilled water by oxida- tion with nitric acid and precipitation by ammonia. Great diffi- culty was however experienced in dissolving the ignited sesqui- oxide of iron in the bisulphate of potash by fusion; some of the pure protosulphate of iron was therefore used after it had been pounded aud thoroughly dried between folds of bibulous paper.Exp. 1. 6.30 grns. protosulphate of iron and 0.28 grn. titanic acid were fused with bisulphate of potash dissolved in cold water and boiled; no precipitate was formed at first but after ten or fifteen minutes’ boiling a precipitate began to form which gra-dually increased in quantity and was coloured with oxide of iron. Exp.3. 6-59 gms. protosulphate were fused with 0.15 titanic acid and bisulphate of potash as before. The mass was diswlved in cold water and the solution boiled. After boiling several hours no precipitate was produced. After the liquid had boiled down to a small bulk in a covered beaker it was filled up with water and boiled again for a considerable time but no precipitate was pro- duced.Exp.3. 429 grne. protosulphate of iron and 0.12 of titanic TITANIC ACID IN CLAPS ETC. acid were fused with bisulphate of potash dissolved in cold water and boiled. After boiling for several hours there were indications of the formation of a precipitate but certainly nothing satisfactory and not sufficient to indicate titanic acid unless that Rubstance was previously known to be present there. From the above expe- riments it is obvious why titanic acid has often been overlooked by chemists and that oxide of iron should always be separated before testing for it. Experiments with Titunic Acid and Ammonia. 2-425 gms. titanic acid were fused with bisulphate of potash dissolved in cold water and precipitated by ammonia; the preci- tate was washed dried ignited and wfighed gave 2-58.2.745 gms. of titanic acid were fused with bisulphate of potash and 200grns. of pure chloride of ammonium added to the solu- tion; it was then precipitated by ammonia washed dried and ignited it weighed 2.775. From the above experiments it is obvious that titanic acid is completely precipitated by ammonia and that ammoniacd salts. do not at all influence its precipitation. My subsequent experiments with titanic acid relate more to its presence in iron ores and pig iron. The method usually given in text-books for analysing iron ores or minerals containing much iron is to dissolve them either in hydrochloric or nitro-hydrochloric acid and separate the siliceous matter,-or if the silica is in the soluble state to evaporate the solution to dryness re-dissolve in acid and after separating the silica to precipitate the filtrate by ammonia.The precipitation by ammonia is open to many objections which in most analyses are fatal to the accuracy of the results. These objections are the precipitation of some manganese with the iron ;the precipitation of the phosphoric acid as phosphate of lime and of some carbo-nate of lime and magnesia. The precipitation of these last two bases may in a great measure be prevented by using great care ; but not so with the former. An extensive experience in the ana- lysis'of iron ores and similar minerals has proved to me that phos- phoric acid and manganese are very rarely indeed absent phos- phoric acid existing from a mere trace up to 4 per cent.The difficulties above described may be obviated by nearly neutra- 328 RILEY ON THE GENERAL OCCURRENCE OF lising with ammonia the filtrate from silica or the insoluble residue (the latter may be either analysed separately or the silica sepa- rated by fusion and the secoud filtrate added to the first) then adding acetate of soda or ammouia iu excess and boiling the solu- tion for some time the oxide of iron and alumina are thereby completely precipitated together with all the phosphoric acid which is entirely free from manganese lime and magnesia. This process also completely precipitates titanic acid if present in the ore. The precipitatc must be washed with boiling water and a few drops of acetate of soda or ammonia added every time it is washed if this is not done the precipitate clogs the filter the washing becomes tedious and some of the iron passes through the filter.This pre- cipitate should then be dissolved in hydrochloric acid re-precipi- tated by ammonia dried ignited rand weighed. Experience has proved to me that this is necessary as in all case.s the precipitate contains silica which is in a great measure separated by re-dis-solving the ignited precipitate in acid. The filtrate from the small amount of silica may be treated with potash and alumina sepa- rated by acidifying with hydrochloric acid the filtrate from the exide of iron boiling with chlorate of potaah and adding carbonate of ammonia the precipitate is then to be ignited and weighed.This alumina contains by far the larger proportion of phosphoric acid but not all as dome is invariably left with the iron. The phosphoric acid may be separated hm the alumina by dissolving it in hydrochloric acid and adding tartaric acid ammonia sal- ammoniac and a magnesian salt. The oxide of iron is re-dissolved in hydrochloric acid precipitcrted by ammonia and weighed if tested for phosphoric acid it will always be found to contain that acid if present in the ore. Should titanic acid be present the oxide of iron is after diesolving in hydrochloric acid reduced with birmlphate of soda the exeees of sulphurous acid is boiled off the solution nearly neutralbed with ammonia acetate of soda or mmonirr dded in excess and the solution boiled.The titanic aeid is then completely precipitated and mag be obtained pure by hing with bieulphate of potash as before described. The filtrate from the precipitate by acetate of soda is treated in a flask whh bmine and ammonia and heated gently then boiled whereby the whole of the manganese is most completely and readily eeparated as peroxide which may-be filtered off rapidly and weighed after washing and drying as Mn,O,. The filtrate is heatedin the ordinary rnannw for lime and magnesia. When TITANIC ACID IN CLAY83 ETC. an iron ore is analysed as above described the eesquioxide of iron ie not obtained in a pure state. The separation of the sesquioxide from alumina by potash is most unsatisfactory; and it will be found that the oxide of iron is too high no reliance can be placed on weighing iron m sesquioxide after it has been separated from aliimina by potash In proof of this it will be necessary to detail some lrpecial experiments made on the determi- nation of iron the results of which prove that the only sure and safe method of determining it is by a standard solution either of bichromate of potash or permangasate of potash; or rather it is never safe to consider sesquioxide of iron as such until it ha been dissolved and treated either by Penny’s method or Margue rit e’s.Careful experiments were made with pure sulphate of iron the same being used as previously described. 6 pints of solu- tion of bichromate of potash was prepared by dissolving 270 gms.of the salt in distilled water and 1pO gms. pure carbonate of potash added to make it alkaline ; 1500 gms. burette was used. A standard solution was prepared by dissolving the finest bright- drawn iron wire in dilute hydrochloric acid in a 30 ox. flask closed with a funnel ; after perfect solution of the iron wire it was filled up with cooled boiled distilled water making in all rather more than a pint of solution. 1 Iron wire 6.525 grs. required meas. solution 1285 :. 10@0=5.0778 93 , 7.075 , 1393 :. lOOO= 50?89 With the above solution the iron was determined first in the pure protosulphate; then in the sesquioxide obtained from the protosulphate after it had been precipitated by ammonia and weighed as Fe,O,. Iron by Standard Solution of Bichromate of Potash.No. 1.FeO.SO330*66required measures 1220= iron per cent. 20.207 , 2 , 34.615 >> 1375 >I 20.172 , 3 , 48.265 >> 1925 9 20-1t89 9, , 4 , 27.29 1087 , 20.227 Mean 20.199 Theory gives 20-144 per cent. The protosulphate of iron was dissolved in water ; the solution acidified with a moderate quantity of hydrochloric acid and 330 RILEY ON THE GENERAL OCCURRENCE OF diluted with rather more than a pint of cooled boiled distilled water. Iron weighed as Fe,O,. No. 1.FeO.SO 33.155 gave Fe,O 9*575=ironper cent. 20-218 J 2 >, 50*04 , , 14.45 J 20-213 ,9 I 3 40'28 , , 11.655 . , 20254 9 jj ,> 4 >> 30.22 8.735 , 20233 Mean result 20.229 The sulphate of iron was dissolved in water peroxidized with nitric and hydrochloric acid precipitated by ammonia dried ignited and weighed.Iron determined in Sesquioxide by Standard Solution of Bichromate qf Potash. The above sesquioxide was dissolved in strong hydrocholoric acid transferred into a 30 ox. flask filled two-thirds full with distilled water and about as much sulphite of soda added as would cover a shilling the liquid being gradually heated and boiled till no smell of sulphurous acid was discernible then cooled in water and treated with the standard solution. No.1. Fe,0,0.575 requiredrneas. solution1 315 =ironpercent. 20.141 , 2 , 14-45 I) , 1991 ,Y 20.141 ,, 3 , 11.655 , , 1604 ,> 20.12 9 4 I 8.735 9 , 1200 ,¶ 20.165 Mean 20.142 In dissolving the seaqiiioxide of iron in acid some gelatinous silica separated in every case; it was however very minute in quantity but distinctly discernible.Comparing the results obtained by determining the iron directly by standard solution determining the iron by weighing as Fe2O9 and again determining iron in the Fe,O by reduction and standard solution we have- By standard Weighing as Determining. solution direct. Fe,03. Fe in Fe,OB. Iron per cent. 20.199 20.229 20,142 Theory 20.144. From the above experiments it is obvious that with a pure salt of iron containing no other base the determination of iron by TITANIC ACID IN CLAYS ETC. weighing as sesquioxide is accurate and that its determination by standard solution of bichromate of potash either in the pure proto- salt or in the peroxide of iron from it agrees in every respect with the former.When however potash is used or any quantity of fixed base is in solution the determination of iron by weigtiirig as sesquioxide is inaccurate ; this will be seen by the following direct experiments. Moreover the results of a very long experience have proved to me that the sesquioxide of iron ohtained in an analysis of an iron ore is always too high ; and it is very rare indeed that the dcterniination of iron by weighing as Fe203 can be made to agree with the determination by standard solution. Experiments with Sesquioxide of Iron and its determination wlken mixed .with Alumina and Tiilanic Acid. Pure sesquioxide of iron the same as prepared from the pro- tosulphate previously alluded to mas used and a standard solution of bichromate of potash 1000 grns.of which were equivalent to 5.28 of iron. 10.39grns. pure sesquioxide dissolved in hydrochloric acid and precipitated by ammonia gave 10.435 Fe20,. This re-dissolved in hydrochloric and reduced with sulphite of soda required 1386 measures of the standard solution of bichromate equal to 10.454 FA* Separation of Sesquioxide of Iron and Alumina by Potash. The potash used for the following experiments was carefully tested and on operating on some quantity traces of silica could be detected; it was however an inappreciable quantity. A little alumina was also detected but too small in quai1tit.y to affect the results ;the same oxide of iron and alumiua prepared as described were used.Sesquioxide of iron 14.47 and alumina 2.225 were weighed out and dissolved in strong hydrachloric acid the solution was transferred to a large platinum howl and well boiled ; the ses- quioxide of iron separated by filtration dissolved in hydrochloric acid re-precipitated by ammonia then dried and ignited weighed 14.705 grns. This was re-dissolved in acid and found to contain a quantity of silica too minute to be weighed; the solution wm reduced with sulphite of soda ; the iron determined by standard solution required 2142 measures. lo00 measures = 4.75 = Iron 10.174 or Fe,O 14.53 RILEY ON THE GENERAL OCCURRENCE OF The filtrate from the oxide of iron after separation by potash was acidificd with hydrochloric acid and well boiled with chlorate of potash then precipitated by carbonate of ammonia and the precipitate was well washed dried ignited it weighed 2.195 which on re-dissolving in acid left no residue of silica.Taken. Obtained byprecipitation. Obtained by standard solution. Excess Fe,O 14-47 14.705 14-53 0.275 hi,O 2.225 2.195 Assuming the above experiment to represent the analysis of an iron ore and that 20 grns. had been taken the difference in the actual amount of sesquioxide of iron present and that obtained would be 0.275 x 5 = 1.375,or a difference of more than one per cent. in the amount of iron. Separation of Sesquioxide of Iron and Titanic Acid. Fe,O taken 14.51 ; TiO 0.21. The titanic acid was fused with bisulphate of potash diasolved in cold water and added to the dis- solved solution of the oxide of iron in strong hydrochloric acid; the mixture was precipitated with ammonia dried after washing and ignited it weighed 14.765.On dissolving it in hydrochloric acid no indications whatever wete observed that titanic acid was present as the oxide of iron dissolvkd completely. The sesqui&loride of iron mas diluted with water and reduced with sulphite of soda the excess of sulphurous acid being boiled off; the solution was nearly neutralised with ammonia and acetate of soda added in excess ; the liquid was then boiled; the titanic acid was precipitated together with a little sesquioxide otiron and was rapidly filtered off; the pre- cipitate of the filter was not washed but dissolved in hydrochloric acid; the iron again reduced as before and the titanic acid precipi- tated by nearly neutralising with ammonia and adding excess of acetate of soda.The titanic acid was thus obtained nearly free from iron. After filtering without washing the filter it was transferred inyo a platinum crucible dried then burnt fused with bisulphate of potash dissolved in cold water and the titanic acid was precipitated by boiling and collected on a filter with the precautions already described. The quantity obtained was 0.20 grn. The sesquioxide of iron was determined by adding all the filtrates together oxidizing with nitric acid and precipitating by ammonia. The quantity 333 TITANIC ACID IN CLAYS ETC.obtained was 15 gms.;this on being re-dissolved in acid waa accidentally lost. In this case the excess was 15.00 -14.51 = 049. Every care was used to have the sesquioxide of iron perfectly washed. Separation of Sesquioxide of Iron Alumina and Titanic Acid. Taken Fe,O 11.08 ; A1,0 2.58 ;TiO 0.20;the oxide of iron and alumina were dissolved in hydrochloric acid; the titanic acid wa fused with bisulphate of potash dissolved in water and added to the solution of iron and alumina. The whole were then precipitated together and weighed 14.07 grns. On dissolving this acid no indication whatever of titanic acid was obtained but there was left a slight gelatinous residue of silica which weighed *08. This was separated and treated with hydrofluoric acid and a little sulphuric acid but left no residue; thc filtered solution was boiled with pure potash in a platinum dish and sesqui- oxide of iron separated.The alumina determined in a similar manner to that described in experiment 1 weighed 2.485 grns.; when re-dissolved in acid it left no appreciable residue of silica. The sesquioxide of iron on the filter together with the titanic acid was re-dissolved in acid and re. precipitated by ammonia washed dried and ignited ; it weighed 11.63 grns. ; this on re-dissolving in acid left a residue of 0.15 silica which gave no appreciable residue on treating with hydrofluoric asd sulphuric acid. The solution from the silica was reduced with sulphite of soda and treated in precisely the same manner as in experiment 2.The titanic acid weighed 0.20gms. The filtrates from the separation of titanic acid hy the acetate were mixed together peroxidized with nitric acid and the sesquioxide of iron was precipitated by ammonia; it weighed 11.215 ens. and was found to contain a trace of silica. The last filtrate from titanic acid was not added to the first two filtrates as it was found on testing it to contain only a trace of iron which did not appear quite pure sesquioxide. The sesquioxide of iron after solution in acid was treated with a standard solution of bichromate of potash of which it required 1644 measures. lOOO=4*75=Fe 74313 or Fe,O 11.16. In this case the excess in the oxide of iron is not very great; it is however occasionally obtained pure or rather nearly so; but this is the exceptioh.Having detailed the above experiments which prove the errom that arise from weighing iron as sesquioxide and com&ring it 334 RILEY ON THE GENERAL OCCURRENCE OF pure without testing it by stmdard solution I shall now give tha results of an analysis of an iron ore very carefully made the result8 being in duplicate; and at tbe same time to show the very grave errors which arise from precipitating the iron and alumina in au iron ore by ammonia. A dispute arose some time since concerning the yield of an iron ore in which samples were sent to an eminent provincial chemist and myself; but no agreement could be made on the yield of the samples ; it was therefore agreed to take a large Sam-ple have it dried finely pulverized and send a portion to each.The samples were identically the same in a fine powder. The analyses made bore not the slightest resemblance the one to the other its seen by the following Table the differences being entirely due to the dangerous practice of precipitating the solution of the ore by ammonia. The method of apalysis already described was adopted and the following results were obtained :-Hygrometric water. grns No. 1. 38.54gms. of ore lost after drying at 212q Fahr. . 1.21 , 2. 38.09 , 9 1.24 Water total amount combined -and hygrometric deter- mined by heating in a glass tube drawn out at end and absorbing water in a chloride of calcium tube :-No.1. 21.145 grns. of ore yielded of water at a red heat 2.14 , 2.18.170 . . .* . . . 1-80 No. 1 By the action of hydrochloric acid (with little nitric) on the ore :-24.52 grns. of ore dry at 212q Fahr. gave of insoluble residue . . . 455 a a , Soluble silica. . . b b 006 Sesquioxide of iron alumina and phoaphoric acid weighed together . b . 15.25 , Contained soluble silica b b . 002 , Sesquioxide of iron . . . 13*84* , Sesquioxide of iron contained phosphoric acid . 0.175 *Y Alumina . . . b . 1.55 , Alumina contained phosphoric acid . 047 , Manganoso manganic oxide . b . 0.05 , Sulphate of lime . . b a 3.10 , Pyrophosphate of magnesia . a b 0.89 Silica sepvsted from aeaquioxide of iron -06 not aaldated in adph ANALYSIS OF OOLITIC IRON ORES.1. 2. Precipitated by Ammonia. Reaulta a. Clay and ssnd .. .. .. .. 18-80 18.42 3". eompmd. Organic matter .. .. .. .. .. 0-60 0.60 Extraneous water .. .. .. 19.20 3. 4. 0. Iron pyrytes .... .. .. .. .. 0.35 0.45 Water of composition .. .. 11-07 13-70 7.03 Peroxide of iron .. *. .. .. .. 49.97 47-98 Metallic iron .... .. .. 33.93 41.99 5771 Protoxide of iron .. .. .. .. .. 5.36 6-31 Oxygen ...... .. .. 14-50 17-94 15.68 Oxide of manganeee .. .. .. .. .. 0.20 0'44 Silica ...... .. .. 15.35 18.99 18.61 Alumina .... .. .. .. .. 5.09 6-48 Carbonate of lime .. .. .. 2-66 3.29 9.12 0. Lime ...... .. .. .. .. 5-20 6.02 Alumina.. .... .. 2-26 2-79 6.48 Magnesia ...... .. .. .. 1.32 1-32 Magnesia .... .. .. 0.4 4 0.54 1.32 Phosphoric acid .. .. .. .. .. l*?l 1.88 Phosphoric acid .... .. .. slight trace. 1-80 Carbonic acid .. .. .. .. .. 4.61 4.93 Oxide of manganese .. .. .. -0.32 Combined water . .. .. .. ..-6-92 7.15 Excesu of carbonic acid. . .. .. -0.76 -Organic matter .... .. .. I -0.60 100*13 99.98 b. Iron pyrytes .... .. -0.40 0-Metallic iron per cent. .. .. .. . 39.39 37-96 Lose ...... .. 0.59 0-73 -100*00 99.97 99.73 Clay and sand contained- ---Silica .............. 16.47 15.77 Alumina ............ 1.28 1-21 Peroxide ofiron .......... 0.34 0.24 Potash ............ 9.28 0.28 I 2,3 and 4 dry at 212" Fahrenheit. w w a 336 BILEY ON THE QENEBAL OCOUBRIWCE OF The iusoluble residue gave of-Pa* 2452 grns.silica containing a trace of titanic acid * 3.91 a35 , Sesquioxide of iron . . 0315 , Alumina . , Traces of lime and magnesia . . . Analysis 2. By the action of hydrochloric acid with 8 little nitric on the ore :-20.74 grns. of ore dried at 212' Fahr. gave insoluble residue . . . 3-76 Sesquioxide of iron alumina and phosphoric acid weighed together . . 12.745 Soluble silica in above . . 0.02 Iron determined in the above by standard solution of bichromate of potash measures required 1600 = Fe,O . 11*017 Standard 1000 measures = 4.82Fe. Determination of phosphoric acid. Mean re- sults % 1-80; therefore 20.74 grns. of ore contain PO . . . 0.37 The total quantity of oxide of iron and alumina &c.12.745grns. diminished by Fe,O 11.017 PO 0-37 and SiO 0.02 leaves alumina . 1.338 Manganoso-manganic oxide . . . . o*ow Sulphate of lime . . 2.490 Pyrophosphate of magnesia . . 0.74 The insoluble residue gave of-Silica . * . 3-10 Iron and alumina 0.41 containing Fe,O . 0.05 Alumina hy loss 0*36-0.10 silica contained in this precipitate . . . 0.26 Determination of Iron direct. 19.75 grns. of ore dried at 212q required 1556measures of standard solution of bichromate of potash whereof 1000 = 4-82Iron = . . 37-97 p. c. 23-90 grns. of ore dried at 2129 required 1877 mea-sures of standard solution of bichromate of potash whereof 1000 = 4-82 . . . 37-85 , From above analysis . . . . 37.78 , Determination of FeO by dissolving the ore in a large flask in a current of pure carbonic acid diluting with cold boiled distilled TITANIC ACID lN CLAYB ETC.38? water and estimating the protoride of iron with standard solution of bichmmate of potash. 61.73 gms. of ore dried at 212' required 535 rn-of standard solution of bichrohate. 62.51 dried at 212O required 4.50measures of standard solution whereof lo00 measures = 41-82iron. Determination of Phosphoric Acid. No. 1. 61.55 grns. of ore dry at 212' gave2Mg0.P05 1.71 2. 42.78 ,, '( 9 9 1-27 The phosphoric acid was determined by the method proposed by A. Dick ; viz. by dissolving the ore in hydrochloric acid filtering off insoluble matter reducing the filtrate with sulphite of soda and boiling off all free sulphurous acid oxidizing a small portion of the solhtion with nitric acid nearly neutralizing with ammonia adding acetate of soda and boiling.All the phosphoric acidis then precipitated together with a small amount of sesqui-oxide of iron some of which goes down as basic acetate. The precipitate was collected and dissolved in hydrochloric acid ; tartaric acid ammonia chloride of ammonium qnd a magnesian salt were added; the liquid was allowed to stand two nights; and the precipitate wm collected filtered and weighed as ZMgO.PO DeterminatiQn of Sukhur. No. 1. 66.51 grns. of ore dry at 212O gave Bt@.SO . 0*%2 , 2. 46.28 , 9, >, . 0-84 The sulphur was determined by fusing the ore with a mixture of pure carbonate of soda and nitre in a gold crucible dissolving in dilute acid evapo-ting to drynesa and separating insoluble matter by redissolving in dilute hydrochloric acid then precipitating by chloride of barium.Determinution of Carbonic Acid. No. 1. 103.19 grns. cf ore dry at 212" gave CO . . 4-76 13 9, 2. 65.24 , . 3-22 The carbonic wid was determined by dissolving the ore in a small flask provided with a safety funnel and coUecting the gas in potash-bulbs after drying it by psing through a chloride of calcium tube. 388 RlLEY ON TITANIC ACID IN CWYB ETC. Organic Matter and Alkalieg. 104-37grns. of om dried at 212O wcre dissolved in hydro- chloric acid and silica, and the insoluble rcsidue was Separated cnrcfully dctachcd from the filtcr and treated in a platinum dish with hydrofluoric acid until all tlic silica was volatilized and thc clay was entircly decomposed ;the partially dissolvcd mass was then treated with strong hydrochloric acid and well boiled and the organic matter left undissolved was collected on a tared filter and weighed .. 0.63 The filtrates from the silica and the filtrate from organic matter were mixed together and precipitated by ammonia and the alkalies were determined as already dcscribed for clays. Alkaline chlorides obtained 0.48 In the analysis of iron ores the author has entirely given up the use of potash; the sesquioxide of iron alumina and phosphoric acid arc weighed together as in analysis No. 2 and then the mixturc is dissolved in hydrochloric acid; any silica it may contain is filterccl off; the iron is determined by standard golution and the sesquioxidc thus obtained is deducted from the mixed precipitate ; then by calculation thc phosphoric acid con-tained in it is ascertained by a special dctcrminatiori made for this acid; this is also deducted and the resitlue is alumina.Estima-tions by loss are generally objectionable but n long cxpcricnce has proved to me that the above method is thc most reliable. Titanium in Pig Iron.-This metal has ody been detected satisfactorily on one occasion in a sample of very siliceous grey pig containing per cent. of silicon ; it was .found in the follow- ing manner :-A large quantity of the pig mas dissolved in hydro-chloric acid to test for metals; the insoluble silica was separated by filtration and the filter treated with nitric and hydrochloric acids again filtered and the solutioz on being evaporated to drive off nitric acid was unintentionally allowed to go to dryness.On redissolking in hydrochloric acid some insoluble residue wm left which was separated by filtration and treated after burning in-a platinum crucible with hydroff uoric and sulphuric acids-it was not silica on fusing with bisulphate of potash it gavethe dis- tinctive and characteristic reactions of titanic acid. In testing pig iron for titanium care must be taken as the author has in many cases obtained precipitates in testing for titanic acid which he PERRINS ON BBRBERINE. 339 considered to be the acid but on further examination found to be pcrphosphatc of iron.In dissolving pig iron in acids if there is much silica and phosphorus some phosphide of iron is almost sure to be left with the silica; and this after being treated with hydrofluorie and sulphurie acids is left as a residue of perphosphate of iron which was in some cases confounded with titanic acid until a more intimate knowledge of its properties had been obtained. Tilanium in Iron Qres.-It is a mistake to suppose that titanic acid is left with.the silica in the analysis of an iron ore or that it is completely separated by evaporation to dryness ;a considerable amount of titanic acid is dissolved by stroiig hydrochloric acid. In an iron ore containing from 20 to 30 per cent.of titanic acid nearly the whole of the titanic acid was dissolved in the hydro-chloric acid and only a small amount obtained with the silica. The author hopes shortly to be able to lay before the Societysome experiments made with rutile in the manufacture of steel and also some details as tg the presence of titanium in iron and steel his present opinion is that it does not alloy to any considerable extent with iron.

ISSN:0368-1769    

DOI:10.1039/JS8621500311

出版商:RSC    

年代:1862

数据来源: RSC

摘要:

339 PERRINS ON BBRBERINE. XLII1.-On Berberine-Contrihtim to its History and Revbkm of its Fomztda. BY J. DYSON PERRINS F.C,S. THEobjects of this paper are to announce some new sources for' the alkaloid berberine to describe several of its salts hitherto un- noticed and to review the formula proposed by Fleitmann. The chemical history of berberine is somewhat remarkable and it will not be out of place here to refer briefly to it. The first notice of this body has hitherto been attributed to Buchner and Herberger who discovered it in Berberis vulgaris in 1835. They erroneously regarded it as a weak acid rather than as a powerful organic base and Buchner's formula has long been abandoned. I find however that Chevallier and Pelletan deserve honour- able mention a8 being the first observers of berberine; they accurately described it under the name of Zanthopicritein 1826.310 PERILING ON BERl3ElLIKE. More recently Flc i t ni an XA * published an account of ''Bcrherine and some of its Salts," clearly establishing its basic character and propouding a formula replacing tliat \vhich had resulted from the previous labours of Bucliner. Fleitmann's formula has obtained general acccptarice,t varied liwcver by Gerhard t who on thcoretieal grouiids proposed the addition of a single cquivn- lent each of liydrogcn and osygcn. Iii addition to many of the Berberidex various other sources for this alkdoid so remarkablc for its beautiful ycllow colour hme been discovcred-by 13o ed c k ert in CoccuZus ycrhulus tlic calumlm root of pharmacy beloiiging to the natural order .ilIeniq~cn/tucec~ ;by St c n h o us e 0 in Cdocline polyearpa natural order Anoizacee an African wood from Sierra Leone ;by myself 11 in C'osci)iiunafewstrutum natural order ,We& spermacee a root from Ceylon; by myselfy also in Xunthorrim apiij'olia natural order Ra'nunculacee a Xorth American plant ; by 11ahla** in Hydrastis Canadensis another of the Ranuncukueea also a North American plant common in the United States the rhizome of which is used in American pharmacy.Some time before the publicatiou of illahla's paper I had noted the occurrence of berberine in H. Canadensis; indeed it was through that observation I was led to make the present inquiry. I can recommend H.Canadensis which may he readily obtained in this country as an excellent and available source for berberine; it yields about four per cent. of the crude alkaloid. In addition to the sources already named I have now to an-nounce the follouiiig new ones it secms unnecessary to describe the methods employed to isolate the alkaloid-they Fere always founded upon its solubility in alcohol and the sparing solubility of the nitrate in solutions acidulated with nitric acid. IU the India Museum there is a yellow dye-wood from Upper Assam called by the native name Wooclur~par;of this I obtained * Chem. Gaz. 1817 vol. v. p. 129; Ann.Ch. Pharm. lix. 60. t Except by h'emp vide Chern. Gaz.v.5 p. 209 who proposed a formuja which has foiind no support; his platinum determination8 agree with Pleitmann's and my own but most unaccouutnLlg his carbon determinations of the platinum-salt are about two per cent.higher than those of auy other chemist before or sioce. $ Chem. Gaz. vol. vi. 302. Q Pharm. J. Trans. 1855,vol. riv. p. 455. 11 Phil. Mag. [4] iv. 69. Ti Pharm. J. Trans. 1S62 vol. iii. 567. * * Silliman's JoumI 1862 rol. xxxiii. p. 43. PERRINS ON BERBERINE. 341 a specimen through the courtesy of Dr. J. Forbes Watson; I find that berberine constitutes its yellom-colouritig principie. I regret that I have been uuable to ascertain the proper botanical name; from its structure it probably belongs to the order Men& spqrnacee. A woody foot called Ruiz de Silo Joao or St. John’s root from Rio Grande I believe twice imported into this country and of which a specimen has been kindly given to me by D aniel H an-bury Esq.F.L.S. &c. abounds in berberine; in this instance also I am unable to give the botanical designation. I gladly avail myself of this opportunity of expressing my sense of the kind assistance I have received from my fricnd Mr. Hanbury in the course of this inquiry. Amongst numerous rare specimens this gentleman has favoured me with is it yellow bark from the Botanical Museum at Kern of which little appears to be known; it is simply named ‘‘Pachnelo tree-yellow c?ye-Boyot&.” This bark T find to be very rich in berberine of which it yielded nearly seven per cent. of its weight If further inquiry should shorn that pachnelo-tkees are plentiful in New Grenada or other districts in South America p most valuable source for berberine will be secured.The next source for this alkaloid which I have to announce is one:of considerable interest ; it-is the root of Coptis Teeta or Mah-mira a ranunculaceous plant of Hindostan and China highly prized on account of its tonic properties and known in the bazaars of India as Mishmee bitter. There is an historical notice of this root from the pen of the late Dr. Pereira.* He regards it as probable that Coptis Teeta is a remedy of great antiquity in fact a classical medicine used in ancient Greece and described by certain Greek arid Arabian authors; in more recent times known in Europe under another name but its origin not suspected ; the first accurate notice of the root by any modern writer was given by Dr.Wallich from whose account I quote :-“&lishme Teeta is the name by which the drug is designated among the Mishmees and Lamas in the mountainous regions bordering upon Upper Asgam. The Chinese call it Honglane ;among these three nations it is in great estimt-ition and universal use as a powerful tonic and stomachic. Quantities are sent down to Assam in neat little baskets with open meshes made of narrow slips of rqtan or some * Phrm. J. Tram. 1551 vol. xi. 294 342 PERBINS ON BEBBEBINB. such material and measuring three to four inch- in length by two and a half in breadth. Each basket contains about an ounce of small pieces of the root from one to three inches long; they are nearly cylindric uneven scabrous more or less curved of a greyish-brown colour and varying in thickness from the size ai‘ a crow-quill to double that diameter.The root is perfectly dry and brittle ; occasionally a few fibrillz are issuing from one end ;the inside is hard somewhat cellular the outside of a dingy yellow colour. The taste is intensely and purely bitter very lasting and with only a very slight aroma. On mastication the root tinges the saliva yellow or gold-coloured it possesses no smell whatever.” This account well describes a quantity of the root which 1 received from the East India Museum through the kindness of Dr. J. Forbes Watson. I soon ascertained that the active prin- ciple of Coptis Teeia is berberine in which the root abounds.I obtained from it eight and a half per cent. which is the largest amount yet met with uor will it probably ever be surpassed. I did not obtain any other crystalline substance from this root. Lastly I have succeeded in establishing the fact that Zantho- picrite obtained from Zanthoxylum Clava Herculis by Chevallier 8nd Pelletan,* in 1826,is no other substance than berberine and that consequently they must be considered as the first observers of this body. My friend Mr. Hanbury again assisted my inquiry by furnishing me with some of the bark of 2.claua HercuZi8 according to Dr. Julius Martiny a German pharmacologist of eminence this bark is somewhat peculiar from its highly laminated texture splitting readily into thin plates like garden bast; this is noticed by the French authors and altogether the careful descrip tion they give exactly applies to the bark which I have exa- mined.The botanical sypongms are 2.clava Hercut% Linn.; 2.Carolinianum Gaertner; and 2. Curibleum Lamarck; it is quite necessary to particularize this in order to prevent the con.. fusion consequent upon the last-named botanist applying the specific term 2.clava Herculis to a tree which is totally distinct. The French chemists do not appear to have attempted the ultimate analysis of their zanthopicrite but they have carefully noted several of its properties and re-actions not omitting the somewhat unusual deportment of this body with sulyhide of * Jonm. de Chemie med. 1826,-vol.ii. 314 ;Note sur le Zant;aoxyluna da Qaraibee ou Clavalier da Antilk8 par MX. Chevallier et Gabriel Pelletan. Thb bark is used in the West Indies aa a febrifuge. potassium. My own rcviilts havc clcrrrly proved tlic idcntity of zan tho picri t c and bcrljcriiic. Z. cha Hc.r.czclis bclongs to thc natural order Rutacecc and furiiislics tlic Iirst rccordcd cxaniplc of bct1)criiic hing a product of :lily platit of tliitt order. I i~ow pro(m’l to t1et;iil tlic numcricnl rcsults I have obtaincd. It SCClklS i1iiiicccssai*y to stiitc in cadi case from which plant I liavc prcparcd tlict salt for analysis; suffice it to say that the wliolc of tlic soiirccs now first aniiouiiccd arc iticlu(1cd. It is not witlimit somc licsitatioti that I idlow mysclf to qucstion tlic coiiclusiotis of chcmists of’ thc cininencc of Plei t mann Bocclckcr mil others;.but iny ow11 resiilts arc so accordant with each otlicr tlic number of atidyscs I liave mah and thc variety of conhinatioiis I liwc csarniiicd arc so cotisiclcrablc that I feel not only jnstifid hi pi*oposiiigan dtcrittioii of the formulit but indcctl corn pcllcd to (lo so. ‘L’crliapa iny licsitation is lessened by tlic rccollcctioii that on a foriiicr occ:isioti I acqiiiesced in Fleitmanii’s formula mid even supposcdthat it was confirmed by my analysis of tlic hydrocliloratc and by a platitinm dctcrmina- tion; but latcr cxpcricncc has shown mc that the hydrochlorate is not suitccl for ultiinatc analysis as by pretty long exposure to a temperature of loO°C.or thcreabouts it iiadcrgoes some dcco& position the colour changes perniianeutly aid much of it becomes readily soluble in cold water yiclding a red solution; in the.se respects it diffei? from the undricd salt thus proving that some alteration by hat has taken placc. Tlic yurc alkaloid itsclf is equally unsuited for analysis and for similar iwasons iiiclccd I find it not cavily prcparcd iii n state of purity With rcgard to the platinum determiuations of soiiic prcviouu clrcniists it is evident that impure yrodwts Iravc bccii cxaniinccl. I fiiid that very many crystallizations arc ircccvsary beforc my of tlic salts of berberinc can be pronounccd purc. I must dso stntc that the numerical rcsults of Fleitmanri agrce with mim in many cases ant1 sup1)o.t thc formula I propose ratlicr than his ow.Fleitmaiin’s formula is C,,H,,NOB.* A glance at these numbers will suggest great doubts of tlicir accuracy thc number of oxygen equivalents and the sum of tliosc of hydrogen and nitrogen being indivisible by two ; Gcrharilt observed this and proposed to represent berberine by C,,H ISNO,,? His alteration has C = 6.0 = 8 ;for the sakc of comparison thcso values will be retahed througk this paper. PEBRINB ON RERBERINE. the effect of increasing tlie atomic weight which my point out as being already too high. The formula I propose is C,,H ;NO, which with Ger h a r d t's is equally free from theoretid objection and I hope to show that it is fully borne out by abundant analytical proof.As the platinum-salt posscsscs many advantages for determining the composition of thc alkaloid I have from time to time examined it ; it may he prepared with ease in a pure state in consequence of its great insolubility ; like every other combination of berberine it map be olJtained in minute crystalline needles by precipitating a hot dilute solution of any berbcriiie salt with hichloride of platinum. When collceted the precipitate shoiiltl be washed with cold water until tlie washings iipcn the additiou of iodide of potassium give no criclciicc of the presence of platinum ; it may then be dried at once in tlic water-oren without any fear of decomposition and it burns wit 1iout dif Fi cu1t,v. Analysis of Chloroplutiizate of Berberine :-No.1.-4*45 1 grains hurncd with lead-chromate gave 7.250 , carbonic acid and 1.36'3 , water. KO. 2.-G.604 grains gave 10*714 J carbonic acid and 2.033 , water. No. 3.-5-681 grains burned xith soda-lime for nitrogen dcter mina t ion gave 1.127 , platinum. No. 4.-5.4-t9 grains gaye on careful ignition -988 , platinum. No. 5.-2.733 grains gave ~67'3 , platinum. No. 6.-5*455 grains gave *99O J platinum. No. 7.-3%79 grains gave *YO5 , platinum. No. 8.-3*781 grains gave ~686 , platinum. PERBINS ON BEBBEBINE. No. 9.-8*350 grains gave -610 , platinum. No. 10.-5.091 grains gave *932 , platinum. No. 11.4310 grains gave *790 , platinum. No. 12.-5*880 grab gave 1-075 , platinum. Percentage corn pwition- 1.2. 3. 4. 6. 6. 7. a 9. io.it.12. C 44.42 44-24 H 3.41 3-42 x 2.80 Pt. 18.13 18.19 1814 18.17 1814 1820 18.31 1833 18.28 leading to the formula C,,H,,NO,.HCl.PtCl as will be seen from the following comparison :-Wcnlrted Pemna. Fleitmann. --lr mean. mean. Po equivs. carbon.. . . 240 M35 44-33 44.39 18 , hydrogen.. 18 3.33 3.41 3-50 1 equiv. nitrogen .. 14 2.59 2430 8 equivs. oxygen.. .. 11.83 8 , chlorine .. 1065 19-68 1equiv. platinurn .. 98.6 18.22 1821 18.11 1equiv. chloroplatinate of berberine ... . .. 541.1 100.00 It should be stated that every determination mas from a different crystallization of the salt often prepared at long intervals. From this one of the most precise methods known it will be seen that not only my own results but Fleitmainn’s also point to the adoption of the proposed formula; that of the German chemist requiring but 17.53% of platinum or less by O.i‘,% ; and of carbon 44.83%; or more by 0*4.”/;’,, a divergence from the fore-going results which appears to me all hut decisive on the point of its inaccuracy.Chloroaurute of Berberine. This combination was examined as possessing an advantage PERRKNS ON BELZLlERlNE. even over the platinum-salt for the object in view owing to the high coinbiiiiiig wcigllt of gold. On adcling tcrchloridc of gold to thc 1iytlroclilor:itc or otlicr salt of berberine the double gold-salt iniincdi:,tcly falls ns an aniorplious brown-coloured precipitate quite iiiso1nl)lc in vntcr ;it is purified for analysis by wasliiug with wntcr aid dissolving iii boiling dilutc spirit from which it crptallizcs on cooliiig in chestnut-brown needles which niay be dried at 100°C.witliout decomposition it burns without difficulty :-No. 1.-8-2W graiiis gnvc on combustion 10.657 , carbonic acid aid 2.004 , water. No.2.-6*862 grains gave 8.03'J , carbonic acid and 1.706 , water. No. 3.-5.600 grains gave on ignition 1.643 , gold. No. 4.-7*988 grains gave 2.317 , gold. No.5.-7.950 grains gave 2-316 , gold. In 100 parts-1. 2. 3. 4. 5. Carbon. ... 35-50 35.50 Hydrogen.. 5.71 2.76 Gold.. ... . 29-34! 29-00 29-13 corresponding to the formula C,,H ,N O,.H C1.AuCI, as the following comparison will show :-Calculated.Experiment. -40 equivs. carbon . . .. 2-1.0 35.5 7 35.50 18 , hydrogen . . 18 2.67 2.74 1 equiv. nitrogen.. .. 14 2.08 8 equivs. oxygen . ... 64 9-49 4 , chlorine.. .. 142 21.05 1 equiv. gold . . .... 196.6 29-14 29.16 -1equiv. doublegold-salt 674.6 100*00 PERBINS ON BEBBEBKNE. Fleitmann does not appear to have examined this dt but according to his formula the amount of gold should be only 28-26% or nearly one per cent. less. The next combination to be described is interesting as be-longing to a class that I do not remember to have seen noticed before viz. the double hyposulphites of silver and the alkaloids. Hyposulphiteof Berberine and Silver is precipitated in a yellow amorphous pulverulent form when to a cold neutral solution of a salt of berberine is added hyposulphite of soda saturaked orhearly so with any silver-salt.The precipitant may be prepared by adding nitpzite of silver to solution of hyposulphite of soda sollong as the precipitate first formed is redissolved; it must be filtered and used while fresh as in time the silver is gradually deposited as sulphide. The double berberine-salt is insolubleiu water but readily so in spirit and in solution of hyposulphite of soda; it is d,ecomposed by ebullition with separation of sulphide of silver. To pkepare the salt for -analysis I add the argentine solution to nitrate of ber-berine dissolved in weak spirit while hot ; the double salt crystal-lizes out on cooling in minute prisms of a pure lemon-yellow colour ; they are readily washed with water and the air-dried salt does not decompose or alter in colour at 100OC.Upon carefid and prolonged ignition nothing is left but perfectly white metallic silver :-NQ.1.-5-958 grabs burned with usual precautions gave 9.381 , carbonic acid and 1-730 , water. No. 2.-6.553 grains gave 10.380 , carbonic acid and 1.910 ,m water. No. 3.-5-56 , grains burned with carbonate of soda and oxide of mercury gave 4.6443 , sulphate of baryta. &o. 4.-6.625 grains gave on ignition 1.290 , siiver. No. 5.-5*997 grains gave 1.165 , saver. PERRINS ON BERBERINE. In 100 parts- 1. 2. 3. 4. 5. Carbon.. . . 42.99 48-20 Hydrogen.. 3.22 3-24 Sulphur . . 11.47 Silver . . . . 19-41 19-42 leading to the formula C,,H,,NO,,HO.S,O,,AgO.S,O as is shown by the following comparison :-Caldated.Experiment. *40 equivs. carbon . . . . 240 43-16 43.07 18 , hydrogen . . 18 3.23 3.23 1 equiv. nitrogen.. . . 14 252 14 equivs. oxygen . . . 112 20-16 4 , sulphur.. . . 64 11.51 11.47 1 equiv. silver.. . . . . 108 1942 19.45 - -1 1equiv. doublesilversalt 556 100.00 Bichromate of Berberine.-This salt has been described by Fleitmann as an amorphous substance. I have to remark that it may be obtained in orange-yellow needles by adding bichromate of potassium to n boiling and very dilute solution of a salt of berberine-the crystals separate entirely on cooling. This salt is extremely insoluble in excess of the precipitant and in cold water but it may be recrystallised from a large quantity of hot water.It burns readily and the green oxide of chromium may thus be determined with exactitude This salt agrees in constitution with the bichromates of ammonia lepidine chinoline &c. in containing only one atom of water :-No. 1.-6-094 grains gave on combustion 11.964 ,) carbonic acid and 2.198 , water. No. 2.-4432 grains gave 8.747 , carbonic acid and 1.624 , water. No.3.-8.490 grains gave on incineration 1480 ,t sesquioxide of chromium. PERRXXS ON BEBBEBINE. No. 4.-10*149 graiiis gave 1.770 , oxide of chromium. In loo parts-1. 2. 3. 4. Carhon ........ 53.54 53.87 Hydrogen ...... 4.00 4.07 Oxide of chromium 11-43 17-44 agreeing with the formula* as is shown by the following comparison :-Calculated.Experiment. 4.0 equivs. carbon .......... 240 53.86 53-71 18 , hydrogen ........ 18 4-04 4-04 1 equiv. nitrogen.. ........ 14 3.14 12 equivs. oxygen .......... 96 2 1-55 1equiv. oxide of chromium. 77.6 17.41 17.43 (Cr*OJ 1equiv. bichromateof berberine 445.6 100-00. Nitrate of Berberine.-This salt has been described by Fleit- mann it is so little soluble in slight excess of nitric acid that it admits of repeated crystallizations without perceptible loss. It dissolves pretty readily in m-ater but separates most completely upon the addition of a few drops of dilute nitric acid. To insure its purity I find it is necessary to cq-stallize repeatedly until the colour of the motlier-liquor is no longer darkened by excess of ammonia n-liich ma>- be considered as a proof that solutions of pure berberine do not assume a red colour upon the addition of an alkali; any change of colour is evidently due either to impurity OF it points to some alteration in the alkaloid.3-itrate of ber-lwrine is to be preferred as the source from which to prepare every other combination; it may be subjected for any length of time to 100’ C. without losing its fine yellow colour having in this respect a great advantage over the hydrochlorate. For analysis I finally crystallized it from hot water to get rid of every trace of free acid. Flei tmann’s analysis of this salt does not agree very closely with mine which is not surprising as he did not obtain it in crystals but examined an amorphous poR-der of difficult purification; his view of its constitution is upsatiafactoq and appears to be erroneous.360 PERBINS ON BERBERINE. I found the nitrate admirably adapted for analysis as the following concordant rcsults will show :-No.1.-5*002 grains gavc on combustion 11.033 , carbonic acid and 2,058 , watcr. No. 2.-5.313 grains gavc 11.504 , carbonic acid and 2.199 ,) watcr. No.3.-4516 grains gave 9970 , carbonic acid and 1.868 , water. NO.4.-4*046 grains gave 8.927 , carbonic acid and 1.673 99 water. No.5.-4*535 grains gave 10.014 ,) carbonic acid and 1.913 -, water In 100 parts-1. 2. 3. 4. 5. Carbon.. .. 60-15 60.18 60.21 60-17 60.22 Hydrogen.. 4.57 4-58 457 459 4.68 corresponding with the formula as is shown by the following comparison :-Calculated.Experiment. Fleitmann.‘ -40 equivs. carbon.. ........ 240 60.30 60.19 59-89 18 , hydrogen........ 18 4.52 4.60 4.68 2 , nitrogen ........ 28 7-03 14 , oxygen.. ........ 112 28-15 1equiv. nitrateof berberine. . 398 100.00 Hydrobromate of Berberine may be prepared by adding bromide of potassium to solution of nitrate of berberine acidulated with acetic acid. It instantly fdls as a yellow precipitate soluble in pure Fleitmann’s carbon determinations were 59-64 and 60.15 per oent. PERBINS ON BEBBEBWE. water but insoluble in excess of bromide of potassium; from its solution in hot water or spirit it falls in yellow acicular crystals which bear a temperature of 100"C.without decomposition but assume a bright orange colobr :-No. 1.-5.450 grains on combustion gave 11.505 , carbonic acid and 2.125 , water. No. 2.-4.9GO grains gave 10.360 , carbonic acid and 1.914 , water. No. 3.-13.308 grains gave 5.936 , bromide of silver. In 100 parts-1. 2. 3. Carbon ........ 5757 57-66 Hydrogen ...... 433 434 Bromine ........ 19-00 corresponding with the formula C,,H,,NO,. HBr as is here shown :-Calculated. Experiment. w 4Qeyuivs. carbon .... 240 57.69 5 7-62 18 , hydrogen.. 18 4-32 4-33 1equiv. nitrogen .. 14 3.37 ' 8 kquivs. oxygen .... 64 15-39 1 equiv. bromine .. 80 19.23 19.00 416 100.00 The salt dried in vacuo lost 5-75 per cent. of water at a tempera-ture of 100°C.which amount agrees pretty closely with three equivalents and consequently it may be represented by C,,H ,N08.HBr.3aq. Hydriodate of Berberine.-Like other combinations of this alkaloid the hydriodate occurs in the form of minute yellow acicular crystals it is easily prepared in the same manner as the preceding salt substituting of course iodide of potassium for the bromide ;the hydriodate is extremely insoluble whether in pure PEBRINS ON BEBBEHINE. water or in excess of the precipitant. It does not lose weight at 100"C. nor suffer any decomposition or change of colour. Highly dilute solutions of berberine yield a precipitate on the addition of iodide of potassium. For analysis it is best prepared by precipitating a .wnk solution of nitrate of berberine in hot dilute spirit with iodide of potassium Crystals fall immediately they may be washed upon a filtcr with water for some time with- out loss :-No.1.-5*905 grains gave on combustion 110199 , carbonic acid aud 2.094 , water. No. 2.-6*495 grins gave 12.329 , carbonic acid and 2.304 , water. No.3.-5-205grains gave 2.602 ,,. iodide of silver. No. 4a.-7-005 grains gave 3.514 , iodide of silver. In 100 parts-1. 2. 3. 4. Carbon .... 51-72 51.77 Hydrogen .. 3.92 3-96 Iodine.. .... 37-03 27.12 corresponding with the formula C,,H,,NO,.HI as the following table shows :-Calculated. Experimeqt. 7-40 equivs. carbon ............ 240 51.83 51-75 18 , hydrogen ..........18 3-88 3.94 1equiv. nitrogen .......... 14 3.03 8 equivs. oxygen.. .......... 64 13.83 1equiv. iodine ............ 127 27.43 27.07 1 equiv. hpdrioilate of berberine 463 100.00 Hydriodate of Biniodo- berberine or Teriodide of Berberine ? This compdund is formed when a slight excess of iodine is added PERRINS ON BERBERIIS’E. to solution of any berherine salt either in mtcr or spirit in the latter solvent it dissolves 011 heating arid crystallizes in the form of transparent red-brown l)risms which are of extremely sparing solubility either in cold alcohol or iii water; in thc latter liquid they may be consitlcred quitc insoluble as thy do riot impart any tinge of colour to it. This compound is riot a siibstitution-product ; nitrate of silver rapidly removcs all the iodine with formatio:i of iiitrate of ber-berine.For analysis tlie substance was dried at 100OC. and biirned with chromatc of lead and a pretty long column of reduced copper-turnings; this salt dried over oil of vitriol does not lose weight at 100 C. No. 1.-6.832 grains gave 8.4(?5 , carbonic acid and 1.585 , water. No. 2.-6*1?0grains gave 7.502 , carbonic acid and 1.424 , water. No. 3.-10.877 grains ignited with pure lime gave 10.733 , iodide of silver. in 100 parts-1. 2. 3. Carbon ........ 33.55 33.43 Hydrogen ...... 2.57 2.58 Iodine .......... 53.36 corresponding with the formula C4oH1,NO,I*HI as is shown by the following comparison :-Calculated. Experiment 40 equivs. carbon .........24.0 33.47 33.49 18 , hydrogen ...... 18 2.51 2.57 1 equiv. nitrogen ...... 14 1.95 8 equivs. oxygen.. ...... 64 8.93 3 , iodine ........ 381 53.14 53.36 1 equiv. of hydriodate of biniodo-berberine .... 717 100.00 PERRINS ON BERBERINE. I have retained the nomenclature adopted by Anderson-for the teriodides of codeine and papaverine with which this salt is evidently analogous; perhaps the name I suggest is the more correct and I prefer it; but as Anderson has preyiously re- marked the rational constitution of these substances is obscure. I have now to describe a remarkalde compound of Iodine with berberine having certain analogies with the quinine-salt termed Herapathite. When dilute solution of iodine in iodide of potas-&urn is added to solution of any salt of hzrlicrine in hot spirit carefully avoiding an excess of iodirze the new suhstance speedily makes its appearance in the form of brilliant green spangles which increase in quantity arz the soliitioii cools; they are iwari- ably accompanied by crystals of hydriodate of berberine or by the red salt last described nor have I been able to devise any method of preparation by which this admixture.can be n-holly prevented. The formation of this new body is an excellent test for the presence of berherine ; minute quantities may be detected by this reaction. Its occurrence seems to be determined whenever tinc- ture of iodine containing hydriodic acid is added to solution of any salt of berberine in hot weak spirit scrupulously avoiding excess of iodine ; rapid agitation appears to proEote its formation and the presence of any impurity to interfere with it.Like Herapathite it bears a strong resemblance to particles of the elytra of cantharides and to murexide; under the microscope it is seen to consist of crystals of a variety of forms but I believe all derived from a rhombic pfism; the larger crystals are wholly opaque ; many of the smaller ones however are sufficiently thin to allow of the passage of light which assumes a red-brown hue sometimes inclining to violet ; but the light is perfectly polarized in this respect also resembling Herapathite with which its optical properties are obviously similar. I obtaiied this compound with the smallest admixture of hydriodate and in the largest crystals by heating in a strong bottle solution of berberine in alcohol of with addition of iodide of ethyl to 100°C.; upou cooling the bottle contains crystals of hydriodate of berberiue but if exposed to full sun-shine for one or two hours the crystals pass into the green salt now under notice.When the change appears to be complete the bottle must be removed from the sunshine or else the crystals will further pass into the red iodine-salt last described. Exposure to diffused daylight for some days may be substituted for sunshine; PEKRIX'r) ON BERBERINE. 85b but with cvery precaution I haw not bccn able to obtain the sub-stance frce from foreign crystals. It is not easy to see why this ~Oclidcof cthyl proccvs succeeds better than others; probably the pdud devclopmcrit c,f frec iodine is important.By this method I have obtained crystalline plates one-fifth of an inch in length by about half that brcadth-of coursc perfectly opaque. When removed from the solution and wcll washed with weak spirit to remove adhering iodine they have a blackish grecn colour with a fine mctzrllic lustre yicldiiig a nearly black powder which does not Bccompose at IOO'C. I am iticliiied to hclicrc that in composition this body is identi- cal with the red salt awl diffcrv from it only in molecular ar- rangcmcnt,-certainly it passcs with thc utmost facility into hytlriodatr:of ~,iriiotlo-bcrl)c:riiio, and rice remci. Xtratc of silver rcmovcs tlic iodinc with tlic satnc casc and with the same forma-tion of iiitratc of ImLcritic.A carbon ad hydrop clctcrminntion yicldccl respectively 35.65 atid 2-78 pr ccnt. or numlms a little higher than they should have hccn doqhtlcss attri1)ut:il)lc to tlic prcscucc of hydriodatc of bcrl)ci*ixic. Ari iodinc clctcriniiiatioii give mc less than the thcorctical cpantity wliich was to 1;c cspcctcd ; one cogent reason why I bclicvc ttic proper clcsigmtion of thcsc salts to be hydriodate of biniodo- bcrbcrine rathcr tliaii tcriodidc of her-berine is founded upon thc o1)serration that tlie green coiiipound is not formed in thc presericc of any substaiicc which decomposes hjdriodic acid c.g. nitrous acid ;tlic prescncc of ordinary swcet spirit of nitre which always contains free nitrous acid entirely prevents its formation.The foregoing analytical results mill I imagine be considered as almost canclusive proof that the proposed formula for berbcrine is the true expression for that base; and cons.cqueiitly the previous belief that this alkaloid contains 42 cquiralents of carbon must be abandoned. Upon the chemical constitution of berberine I have no new remark to offer beyond the ohscrvation that the action of iodide of ethyl results only in the formation of Iigdriodate. I did not obtain any ethylated compound ;but the substitution-products of berberine well deserve careful study. F1c i t m ann has glanced at a sulphur-compound; I believe it will be found that more than one such exist; the same may be said with regard to nitric acid PERRTNS ON IIERBERXNE.brominc clilorinc kc. Flci tm nnn has iioticcrl what may hc termed the-ultiinntc action of nitric acid; but tlicrc :qq-war to be scveral internicrliate products tlie knomlcdge of wliicli will doubt- less reward future inquiry. Berberine cviclently occupies a position among tlic Yegctal alkaloidst of grcat intcrcst in a scientific poilit of Yicw-n position far more prominent than has liitlicrto bccn assigned to it ; if noticcd at a11 in our Manuals it is disinisscd in half a dozcn lincs. From inquiries which can be termed littlc niorc tlmn superficial its occurrence has bccn shown in niimcrous plants lxlongiiig to no less than five of the great vegetal faniilics-tlic natural orclcrs of the botanist-nor can it be doubted that many other sourccs yct remain to be discovered; its gcographical distribution cwn it1 the present state of our knowledge is all but univcrsal ; it is to be found in almost every country certainly in every clivate and in these respects it claims preccdence over all the other alkaloids.As regards its usefulness to man I hclierc its importance is not yet fully recogiiised. Though it has been long used as a fine ycllom dye more especially for animal tissues its chief claims to use- fulness do not reside in its application to the economic arts- doubtless its therapeutic effects merit much careful investigation. Natural instinct has pointed out its value for the alleviation of human suffering to nations widely separated and enjoying different degrees of civilisation.The polished Greeks the semi-barbarous nations of Hindostan and China the aTorth American Indians and the natives of tropical Africa have been all impressed with the medicinal value of berberine. In the West India Islands and in American pharmacy its virtues have long been recognised though derived from different plants and veiled under erroneous names certainly it holds a place in European pharmacy but one of little prominence; yet it seems to possess properties scarcely inferior to quinine itself. Various medical writers have insisted upon its advantages as a remedial agent; their arguments it would be out of place here to recapitulate; but I am persuaded that nature has not placed berberine in nearly every country without some adequate purpose; there are evidences that its value is becoming better understood amongst ourselves and I confidently anticipate that ere long its reputation will be greatly increased.

ISSN:0368-1769    

DOI:10.1039/JS8621500339

出版商:RSC    

年代:1862

数据来源: RSC

摘要:

357 WONFOK ON A COMPLEX CYANIDE ETC. XLIV.-On a Complex Cyanide of Iron Copper and Potassium. BY WILLIAMJ. WONFOR Student in the Laboratory of the Nuseum of Irish Industry. THIS coinples cyanide crpstallised in-the form of reddish brown crybtills froni a solution which had been employed in electro-plating and was afterrnards set aside and left undisturbed for sc\-eral rnontlis; during that time tlie crystals made their appcarancc. These ci*ptals for the measnrement of which I arp indebted to Professor W. H. Miller of Cam-bridge belong to the cubic system ; they are combinations of the cube and ootohedron. They resemble the an-nexed figure the faces marked Q being th.e faces of the cube and the faces marked 0 those of the octohe- dron. The angle between perpendl'culars to any tFo ad-iacent faces a,is 90".The angle between perpendicular? to any two adjacent faces 0 is 70" 30'. The angle between perpendicular to any face a and an adja-cent face 0,is 54" 44. The following estimations give the amount of water lost rn the water-bath :-I.-1.936 grm. lost *Of325 gym. or 4.2613 per cent. 11.-0.9175 , , *0100 , 4.3590 , III.-0*5355 , , -0675 , , 4.3310 , Mean -4'3171 , For the estimation of the copper iron and potassium the cyanide dried 'at 212"F. was decomposed by Nordhausen sulphuric acid ; the copper was first precipitated by sulphide of hydrogen ; and the sulphide of copper was redissolved in nitric acid pre-cipitated by potash and estimated as oxide in the usual way. The iron was peroxidised then precipitated by ammonia and WONFOR ON A 'COSIPLEX CYANIDE ETC.weighed as peroxide; whilst the potassium was weighed as sul-phate of' potash. The analyses yielded the following results :-1.-1.2972 grm. gave *1966 grm.of FeJOJ& -6245 grm. of KOSO II.-1*6431 ,) , *2494 ,) Fc,O & '4718 , CUO III.-1*0735 , , -3111 , CUO & '5168 , K9S03 The nitrogen was estimated by Will and Varrentrapp's method the substance employed being dried at 212"F. :-1,-*8€8 grm. gave 2.447 grm. of T\3'H4Cl,P1,CI,=*15345of N. 9, II.-*7895 , 2.180 , =.1365 , The organic analyses were made with chromate of lead the substarce employed being dried at 212' F. :-1.-*4836 grm. gave *2617 grm. oE CO & 00616grms. HO. 11.-*6410 , , 0345 , 9) & *0828 J> >> I.11. Mean. Iron ........ 10.609 10.625 10.617 Potassium.. .. 21.608 21.611 21.609 Copper ...... 23.139 23.230 23.184 Nitrogen .... 17,284 17.289 17.287 Carbon ....... 14.758 14680 14.7l9 Hydrogen.. .. 1-461 1.435 1.4443 Oxygen.. .... 11*14l 11.130 11.136 1~00*000 100~000 100000 -I- These results may be expressed by the following calculations :-Calculated. 2Fe ............ 56 10.113 3K ............ 117 21.127 4Cu :... ........ 126.8 22.896 7N ............ 98 17.696 14C.............. 84 15168 8H .......... 8 1.444 80 ........... 64 111556 -553.8 100~000 GREVILLE WILLIAMS ON FORMATION OF IODIDES wrc. 359 This salt lost in the water-bath 4.3171 per cent.; bad it lost 473 it would correspond to 3 equivalents of water; this would give 11 as tlic total number of equivalents ; but I am irrcliricd to think from a dctermiiiation of the water.which I madc by coml)ustion in an undried portion that tlrc true nurnbcr of equivdents of wtiter is 10 Tlicsc-calciilatioris lcad to thc formula :-(3KCy.2FeGy.3Cn2Cy) + 10IIO. It is evidently the same substance that nolley found clepositcd in a copper solution which had been employccl in elcctro-plating ; and subsequently Moldenhauer seems to havc formed it-if we may trust the incomplete analysis he has given-by boiling a solution of subcyanide of copper in a solution of ferrocyanide of potassium.

ISSN:0368-1769    

DOI:10.1039/JS8621500357

出版商:RSC    

年代:1862

数据来源: RSC

摘要:

GREVILLE WILLIAMS ON FORMATION OF IODIDES wrc. 359 XLV.-On the tlirmation of the Iodides of the Alcohol-radicles from Boghead Naphtha. BY C. GREVILLE WILLIAMS,F.R.S. THEpossibility of passing from the bibasic to the monobasic radicles by the addition of hydrogcn to an olefiant tlrrongh the medium of' a hydracid was first shown by RI. Ecrtliclot. The reaction with hydriodic acid is rcprcserited by the equation :-CnHn + HI = CrlHnflI. This reaction has been of the greatest service to me in pursuing my researches upon the hydrocarbons produced during the distilla- tion of Boghead coal. My first experiments were madc to ascertain whether homo-logues of benzole and of marsh gas would by dilution prevent the action of the hydracids on thc comparatively small quautity of the olefiant present.With hydrochloric acid this would appear ta be the case. I then resorted successfully to fuming hydri- odic acid having a density between 1.8 and 1.9; a less con-centrated acid has little action. 360 GREVILLE WILLIAWH ON FOItMA'l'IOY OP IODlDE8 OF Tlic following process ;rppearccl to yicld thc iodidcs more rcadily than ally otlicr yet tried. Tlic mplitha of a boiling point cor-respondiiig with that of tliq olcfiiirit to he cxpcrimcntcd on was placcd in a flask with B ricck thrce or four fcct long. About half the hulk of fuming hytlriodic wit1 having 1)ccn added tlrc mixture wiis cohobatcd for two or tlircc hours. 'l'hc ncck was thcn cut off ant1 rcplnccd by ti hit tdx cotiiicctcd with ii condciisittg appa-ratus.On applyitg n gcwtlc lieat tlic Iiytlrocarl~ons tiiiuctcd on slowly tlistillcd tt\\'ity. TIN rnoi*c vohtilc portioii having in this maxiucr bccn mrnoved tlie distillation was carricd on in a current of stciim until the distillate bcgaii to sink in water. The receiver was then changed and the product collcctcd apart. By proceeding in the manner dcscribcd I havc obtained from Boghcad naphtha thc iodides of aniyl ocnanthyl capryl and pclargonyl. It is evident therefore tlint I~oglica~l naphtha may now be made to yicld an almost irifiiiitc variety of products some of thcm belonging to organic group which Iiavc hitherto almost cscapcd iiivcstigatiou. Tlic quantities of the iodides produccd up to the present time bavc been too small to allow Jircct analyses to be made it became necessary therefore to employ some rcaction by which a small quantity of iodide might be made to yield a comparatively large amount of a substancc capable of hcing purified and analysed.For this purpose nothing appcarcd moie suitable than the com- pound ammonias because a very small amount of basc could be madc to y icld a large quantity of platiuum-salt. With this interitioii tlie iodklcs were scctlcd up in strong tubes with a large cxcess of ~icollolicariimonia and hcated to 100" C. for twelve hours. On dpening the tu1)cs and supcrsaturating the fluid with hydrochlpric acid a small quantity of oil 'remained undissolved which was carcfully rcmovcd. Tlic soluble portion was then evaporated nearly to drylicss to expel the alcohol and traccs of hydrocarbons.The solution distilled with cxcess of hydrate of potassium yielded ammonia and an oily bqe. On adding a great exceas of solid hydraie of potassium to tlie mixture the alkaloid separated almost entirely and after distillation was &is-solved in bydrochloric acid and treated with m excess of chloride of platinum. The strength of the solution was so adjustcd that no immediate precipitation took place. By exposirig the dish con- taining the mixture to a surface of sulphuric acid for a few hours the salt wasgenerally procured in fine crystals. In this manner THE AI,COIIOL-RhDICl4E8 FROM BOGHEAD NAPHTHA. 361 the platinum-salts of amylaminc awanthylamine caprvlamine and pclargorwnine werc prqarcd.The second and fourth of them ))apes arc entirely ncw and it is believed that none of them have evcr hcforc hccn procurcd from a homologuc of olefiant gas. I have not as yct bcc:ial)lc to obtain any iodide of caproyl. Ph tinum-salt of Amylamine. Amylcnc is prcscnt in such small qiiautity in Boghead naphtha that only a wry minutc! portion of iodide of amyl could be obtairicd T rccogniscd the h,vdroch!orate at once hy its peculiar fitty sppcarance ; arid tlic platinum-salt crystallisecl in supcrb scales exactly resemhliig thc salt which I had often had occasion to preparc by the ordinary processes. The following numbcrs werc obtained on analyses:-1.-0.2 133 gramme of platinum-salt of amylamine gave 0*0716 gram me of platinum. 11.-0*2004 gramme of platiiium-salt of amylaminc gaye 0.0682 gramme of platinum.Or in per centages :- Experiment. Yeaa. Theory. I. 11. 33-48/ h 3413 \ 33.76 33-76 Platinum-salt of GTnurithylamine. I have already shown the presence of enanthylene in Boghead naphtha.* The quantity of iodide of oenanthyl formed appears to be exceedingly small and I was only able to obtain enough platinum-salt for one determination. It consisted of beautiful orange-coloured scales. 0.1186 gramme of platinum-salt of enanthylamine gave 0-0366 gramme of platinum. Experiment. Theory. 30.86 30.79 Platinum-salt of Caprylarnine. The iodide of capryl appears to be formed more readily than its congeners. The crystals of the platinum-salt of the corm * Philosophical Transactions 1858.362 GREVILLE WTLLIAMS ON FORMATION OF IODIDE8 ETC. responding base consisted of beautiful golden sesles some of them a quarter of an inch in diameter. They were soluble in alcohol and ether ; the salt was therefore washed with a little water and pressled between folds of filtering-paper. Several grammes were prepared with comparative ease. The following numbers were obtained on analysis :-I.-0.3432 grm. of platinum-salt of caprylamine gave 0.3616 grm. of carbonic acid and 0'1906 grm. of water. II.-05?195 grm. of platinum-salt of caprylamine gave 0.0645 grm. of platinum III.-0.2084 , 0'0614 ,, 91 IV.-O*2028 9 I 0.0596 , Y.-0*2066 9 I 0-0616 , I. II. III. IV. v. Mean. Calculation. Carbon 28.73 28.73 CI6 96 28.62 Hydrogen Nitrogen 6.17 .. . 6.17 H20 . . . N 20 14 5.96 4.17 Chlorine . . . . . . C13 106.5 31-74! Platinum . . . 29.38 29*46 29.39 29-81 29-51Pt 99 29.51 3355 100~00 The first and fourth analyses were made on the same specimen ; the second third and fifth upon distinct preparations in each caset Platatinurn-salt of Pelargonamine. The iodide of pelargonyl was formed from Boghead naphtha in sufficient quantity to enable me to attain the hitberto unknown volatile alkaloid pelargonamine. The crystals of the platinum- salt although of a rich golden-yellow were less beautiful than the others and on drying at 100OC. caked slightly together. They did not however become in the least discoloured. The annexed numbers give the results of the analyses- 1.-0.3978 grm.of platinum-=It of pelargonamine gave 0.4474 grm. of carbonic acid and 0-2304 grm. of water. II.-0.1184 grm. of platinum-sslt of pelargonamine gave 0.0340 grm.of platinum III.-0.2132 99 8 0.0604 , IV.-0.2364 9) 1) 0 0678 JS FRANKLAND ON ORGANIC COMPOUNDS ETC. 363 I. II. III. IV. Mean. Calculation. I-Carbon 30.70 30.70 C18 108 30-90 Hydrogen 6-44 6-44 H2* 22 6.30 Nitrogen . . . . .. . N 14 4.01 Chlorine . . . . . . C13 106.5 30.47 Platinum . . . 28.71 28-33 28.68 28.57 Pt 99 28.32 349.5 100~00 Each platinum-determination was made on a different specimen. I hope eventually to submit to the Society several more sub-stances obtained from Boghead naphtha by the agency of hydrio-dic acid. It is evident that several of the true radicles may now be prepared by acting on the above iodides wits sodium.

ISSN:0368-1769    

DOI:10.1039/JS8621500359

出版商:RSC    

年代:1862

数据来源: RSC

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FRANKLAND ON ORGANIC COMPOUNDS ETC. 363 XLVI.-.On a Nau Series of Organic Compounds contuining Boron. By Dr. E. FRANKLAND, F.R.S. [From the Philosophical Tranaactions for 1862.3 (Abslract.) THEsubstitution of a compound organic radicle for an elementary constituent in inorganic compounds has proved itself to be one of the most important and fertile fields of modern chemical investi- gation. The application of this species of substitution to the inorganic compounds of metals has called into existence an entirely new and extensive family of organic substances- the organo- metallic compounds-bodies never met with in nature distin- guished by well-marked affinities and capable in some instances of effecting in their turn numerous substitutions of a like character.The realization of a similar substitiition in the case of certain inorganic compounds of nitrogen and phosphorus has in the hands of H ofman n not only enriched the science with a host of new and interesting compounds but has also brought our know-ledge of the organic bases to a degree of completeness which can-not be rivalled in any other class of organic compounds. Lastly FRANKLAND ON A NEW SERIES OF attempts liare riot been wanting to estend these reactions to the oxygeri-com!)ouncIs of the metalloids ; arid alrhough this portion of the ficlil pescnts difficulties of a sorncwliat more formidable character yet tlicec attempts have riot unfrcqiieiitly bccn attended wit11 succcss. Tlius iiitiic oxide has Ixcn transformcd into dinitroctliylic and diiiitromctliglic acids ;* sul1)liurous ariliydiidc into ctli~~ioditliioiiic and mctliylotrithionic acids ;t anti carbonic anlijdridc into propionic aiid acetic acitls ++ The last-nnmcd rcrictioii confirming as it did tlic view pre-viously cspresscd by K olbc arid niysclf,$ that organic compounds in geiicral arc nothiiig more tlian substitutions of this nature effcctcd in csrboiiic oxide in carbonic acid arid possibly ill otlicr inorganic compounds of carbon naturally amakencd a dcsirc to extend this iiiqiiiry to the oxygen-corn pounds of boron and silicon which are usually regarded as poescssing certain important analogies with carbonic anhydride.With this end in. view boracic ether was submitted to the action of zincetliyl by Mr.Duppa and myself. We fourid that the wvholc of the oxygen in boracic acid became replaced by ethyl and in a short communication to the Royal Society,(I we described some of the properties of the remarkable body boric ethidc thus formed. In thc further study of this substance and the extension of the research to the homologous methyl-compound I much regret having beeri deprived of the co-operation of my friend and fellow-labourer who had rendered me such valuable assistance at the commence- ment of the investigation but who was reluctantly compelled to abandon its further prosecution. The first attempt to replace oxygen by ethyl in boracic anhy- dride was made by cxposing the latter in a finely pulverized condition to the action of zinccthyl at various temperatures but it was found that the zincethyl was utterly pawerless to effect the lesired substitution ; neithcr did tlie anhydrous acid yield in the slightest degree to W anklyn’s compound of sodiumethyl and zincethyl although it was digested and heated with it for several days.Therb could scarcely be a doubt that the intractability of * Philosophical Transactions for 1857 p. 59. .t. Journal of CLemical Society vol. x p. 55 and p. 243. $ Ibid. vol. xi p. 102 ; and Proceedings of the Royal Society vol. x p. 4. $ Ann. Ch. Pharm. ci 267. Proceedings of the Royal Institution of Great Britain for 1858. I1 Proceedings of the Royal Society vol. x p. 568. ORGANIC COMPOUNDS CONTAINING BORON. tlic anliydridc was due in grcat mcasure to its total insoluldity in tlic surrounding liqid and thcrcforc in orclcr to place it uridcr conditions morc fiivourablc for tlic action of the orgmio-metallic body it was convcrtcd into boracic ctlicr.Thc etlicr was preparcd by Rose's process,* wliicli consists in distilling an intimate mixturc of sulphovinatc of potash and dricd borax. The best proportions were found to be two parts by weight of borax and tlirce parts of the sulphovinatc; but the yield of ctlicr was very small the greater part of thc product consisting of alcohol. The removal of the latter by rcctification as recommended by Rose involved tlie loss of much ether; recourse was tlicrcfore had to chloride of calcium for its abstrac- tion a method wliicli gave very satisfactory results the product of pure.ether being morc than doubled.The following is a sketch of tlie proccas finally adopted :-About 3lbs. of the miscd horan and sulphovinate of potash \-yere put into an ordinary Papin's digester which was placed in 2 sand-bath and exposed to a vcrg gradually increasing heat so long as voltitile products camc over. The crude distillate obtained from several such operations was then treated with about one-fourth of its weight of fuscd chloridc of calcium and agitated until the lattcr was dissolved. TIic liquid now separated into two layers ti lower one coiisisting of an alcoliolic solution of cliloride of calcium and an uppcr onc con-taining nearly all the boracic ether which retained only a sinall proportion of alcohol in solution.The upper layer was tlccarited and submitted to distillation. It began to boil at about 85O C. but the thermometer soon rose to 118"C. between which temp ratiire and 125' C. the greater part of tlic remaining liquid passed over and was rcservcd for the pui*poscs of tlrc iiivestigation. A thick oily liquid remaincd in the retort and appeared to consist of boracic acid united with a smaller proportion of oxide of ethyl. On adding zincetliyl to the boracic ether thus prepared a considerable elevation of temperature gra(1ually occurred whilst at the same time a most penetrating and psculiar odour was developed due appareptly to the vapour of some volatile body which not unfiequently burst into flame whcn the cork was removed from the flask in which the reaction took place.Some preliminary experiments showed that this volatile body could be distilled unchangcd from the mixturc aid that it was neither miscible with nor apparently decomposed by water. It was also * Pogg. Ann. xcviii 245. FBANKLAXD ON A NEW SERIES OF epontaneouslp inflammable and the beautiful green flame with which it burnt demonstrated the presence of boron as one of its constituents. In order to prepare this body in sufficient quantity several OUIICRS of boracic ether were placed in a capacioiis flask closed by a doubly perforated cork. Through one of these perforations passed a thermometer and through the other a short glass tube one-fourth of an inch iu. diameter and open at both ends the bulb of the thermometer clipped into the boracic ether.Successive quantities of pure zincethyl were introduced through the short glass tube by means of a pipette the elevation of temperature after each addition being allowed to subside before the next portion was added. The failure of a further addition of zincethyl to produce any rise of temperature was regarded as evidence of the completion of the reaction which was not attained until a comparatively very large amount of' zincethyl had becn added. The liquid in the flask was now submitted to distillation in an oil-bath. It berm to boil at 04"C. and bctwecn this tcmperature and 140" C. a considerable quantity of a colourlcss liqnid distilled over. The distillation then suddculy stopped and to avoid secondary products of decomposition by the application of a greater heat the operation mas intcrrupted.On cooling the materials remaining in the flask solidified to a mass of large crystals of ethylate of zinc arid ziiicethyl. On rectification the distillate began to boil at 70" C. but thc thermometer rapidly rose to 95" at which temperature the last two-thirds of the liquid pasmrl over and were received apart. The product thus collected exhibited a constant boiling-point on re-distillation. The combustion with oxide of copper of this liquid and the remaining boron compounds described in this paper presented Some difficulties owing partly to the volatility of boracic acid in aqueous vapour and partly to the tendency of that acid when fused to encase particles of carbon and prevent their oxidation Fortiinately the errors thus ititroduced were not so considerable as to throw any doubts upon the analytical results although in many cases the excess in the percentage of hydrogen arid the deficiency in that of carbon are somewhat greater than usual.To estimate the boron in the liquid obtained as above dcscribed advantage was taken of the complete decomposition of the coni-pound when heated to 100" with concentrated nitric acid in sealed tubes. The whole of the boron was in this way conv'erted into ORGANIC COMPOUNDS CONTAINISG BORON. 367 boracic acid; but the latter could riot be determined by the direct evaporation of the nitric acid solution the loss of boracic acid amounting in such an operation to 15 or 20 per cent.of the whole amount. n'one of the known processes for estimating this acid appeared to be eligible in the. present instance and it therefore became necessary to seek for a 'new one. After the trial of various methods With but indifferent success it was found that the evaporation of the acid solution of boracic acid with a known weight of magnesia in excess the residue being then ignited presented a process which although far from rigidly accurate could not in the case of the boron-compound to be analysecl diminish the amount of boron to a greater extent than about 0-2per cent. The analytical numbers agree with the formula as shown by the following table :-Calculated. Mean of analyses. . F .. c12 * .72 73.55 73.15 HI5 ' . 15 15.42 15.61 B. . 10.9 - 11.03 11.08 97.9 100*00 99-84 The new body may be conveniently termed boric ethide. It is evidently formed by the replacement. of the three atoms of oxygen iu boracic acid by three atoms of ethyl according to the following equation :-+ 6'i,51 0,. Boracic ether. Zincethyl. Boric ethide. Ethylate of zinc. The ethylate of zinc thus produced combines with zincethyl to form the crystalline compourid above alluded to. Hence the very large amount of zincethyl which was found necessary to complete the reaction. FRANKLAND ON A NEW SERIES OF Boric ethide possesses the following properties :-It is a colour- less mobile liquid of a pungent odour; its vapour is very irritating to the mucous membrane arid provokes a copious flow of tears.The specific gravity of boric ethide at 23" C. is 0.6961 ; it boils at 95" C. A determination of the specific gravity of its vapour by Gay-Lussac's metliod gave the number 3.4006 which agrees very closely with that calculated upon the supposition that boric ethide is volurnetrically composed like terchloride of boron as is seen from the following calculation :-l'vol. Boron kapour . -75319 3 vols. Ethyl . . 6.0117 The 4 vols. condensed to 2 vols . . 2)6.76489 3.38244 The density of boric ethide vapour increases considerably as the temperature approaches the boiling-point ; thus a determination made at 132" gave the number 3.5979 whilst a second showed the specific gravity of the vapour at 101O.6 to be no less than 3.757.Boric ethide is insoluble in water and is very slowly decomposed by prolonged contact with it. Iodine has scarcely any action upon it even at 100° C. It floats upon concentrated nitric acid for seveml minutes without change ; but suddenly a violent reaction takes place and crystals of boracic acid separate. When boric ethide vapour comes in contact with air it produces slight bluish- white fumes which in the dark are seen to proceed from a lambent blue flame. The liquid is spontaneously inflammable in air burning with a beautiful green arid somewhat fuliginous flame. In contact with pure oxygen it explodes. Excluded from the air boric ethide is quite a stable body; a quantity of it kept in a sealed tube for two years exhibited on examination no evidence of any alteration.When boric ethide is heated to 99' C. with strong hydrochloric acid over mercury a considerable quantity of hydride of ethyl is slowly evolved the reaction being ORGANIC COMPOTTNDS CONTAINING BORON. When boric ethide is heated with watcr to 139' C. for several hours it also appears to sufferan ;.lnaLlogousdecomposition although with extreme slowness ; even with hyclrucliloric acid the action is SO tedious that I have not been able to prepwe a sufficient quantity of boric chlorodiethide (B(C,H,),Cl) to examine its properties. In the cold a strong solution of hydrofluoric acid has no action upon boric ethide which also suffers scarcely any change by being heated to 9$' C.for four hours with concentrated sulphuric acid. Gently heated for fourteen days with sodium in a sealed tube boric ethide underwent no visible change. Ammonia-Boric Elhide. If a few drops of boric ethide be passed up into a dry eudiometer filled with mercury and dry ammoniacal gas be then admitted into the same tube each bubble of gas collapses with a shock like that produced by a bubble of steam projected into cold water A large quantity of ammonia is thus absorbed .by boric ethide with extreme energy. To prepare the compound thus formed in larger quantity several grainrues of boric ethide were placed in a small flask filled with nitrogen and surrounded with ice a current of dry ammoniacal gas was now passed into the flask as long as it was absorbed; finally the product thus obtained was warmed to expel excess of ammonia and then exposed in vacuo over sulphuric acid for twenty-four hours.It did not crystallize and and could not be distilled except in vamo without decomposition. Submitted to analysis it yielded 61-43 per cent. of carbon and 15.43 per cent. of hydrogen. The formula requires 62.66 per cent. of carbon and 15.66 per cent. of hydrogen. The unavoidable slight oxidation of the boric ethide during the necessary manipulations affords a sufficient explanation of the deficiency in the amounts of carbon and hydrogen exhibited by the analysis. 1 should however have made renewed attempts to obtain this body in a state of greater pnrity had not the investiga- tion of the corresponding crystalline methyl-compound described below left no doubt that the formula above given expresses the composition of ammonia-boric ethide.Ammonia-boric ethide is a somewhat oily liquid possessing au aromatic odour and an alkaline reaction. Carbonic acid has no FRANKLAND Oh' A NEW SERIES OF action upon it even in presence of water but other acids decompose it instantly and liberate boric ethide. When it is exposed to a measured quantity of atmospheric air there is scarcely my perceptible absorption of oxygen even after the lapse of several hours. Boric Dioqethide. When boric ethide is placed in a flask and allowed to oxidise gradually first in dry air and finally in dry oxygen it forms a colourless liquid which boils at 125" C.but cannot be distilled under atmospheric pressurc without partial decomposition. At the ordinary temperature this product of oxidation evaporates without residue in a stream of dry carbonic acid. It can be distilled in Bacuo without decomposition and a portion so rectified yielded on analysis results agreeing with the formula Iregard this liquid as a compound of dnic ether with a body having the formula B and derived from boracic acid by the substitution of one equivalent of ethyl for one of oxygen. For this body the name boric dioq-ethide is appropriate whilst its ethereal compound may be con-veniently termed diethylate of boric dioxyethide. The formula of the latter will therefore be The formation of diethylate of boric dioxyethide from boric ethide may be thus represented :-This view of the constitution and mode of formation of the oxidised product is supported by its hehaviour with water ; for when diethylate of boric dioxyethide is placed in contact with ORGAXIC COblPOUh'DS CONTAINIKG BORON.37I water it is instactly decomposed alcohol arid diihydrate of boric dioayethide being formed according to the following equation :-Diethyhie of boric Dihyclrste of boric dioxyethide. dioxyethide. Dihydrate of boric dioxyethide may be conveniently prepared in a state of purity by agitating its aqueous solution with ether which dissolves the boric compound. The ethereal solution must then be decanted and on evaporation at common temperatures in a stream of dry carbonic acid the new compound is left behind as a white and very volatile crystalline mass.The latter was sublimed at a gentle heat in a current of dry carbonic acid and was made to condense in weighed tubes for analysis. Dihydrate of boric dioxyethide is a colourleas volatile crystal- line body very soluble in water alcohol and ether. It possesses an agreeable ethereal odour and a most inteusely sweet taste. Exposed to the air it evaporates at ordinary temperatures under- going at the same time partial decomposition arid iiivariably leaving a slight residue of horacic acid. It may be sublimed without change at about 40° C. in a currelit-of dry carbonic acid and then condenses in magnificent ci*ptitlliiic plates resembling naphthaline. It fuges at a gentle heat and at a higher tem-perature boils with partial decomposition.Its vapour tastes intensely sweet. Boric dioxyethide might be regarded as the anhydride of a bibasic acid the diethylate of boric dioxyethide would then be the ether of this acid whilst the volatile crystalline body juet described would be the hydrated acid itself'. The latter does in fact redden litmus paper but in other respects its acid qnali'ties are very ol>scure and I have not been able to form definite salts with it. It therefore scarcely possesses a valid claim to a place amongst the acids. Considering boric ethide to be formed by the substitution of tb ethyl in zincethyl for the 0xygen.b boracic acid Mr. Duppa 8136 myself expressed the reaction as follows :- FRANKLAND ON A NEW SERIES OF Anothcr hut lcss prolmlh vicw of the changc prcseiits itself in tlic snppositioii tht tlic tliwc atorris of ethyl in boric ctliidc were nlrcrdy 1)rcsc:iit in tlic horacic ctlicr tlie action of tlie zinc-ctliyl lxiiig simply to rwiovc tlic wliolc of tlic oxygcii from thc borucic ctlicr.Kcl<iilL* has iu fact ucloptcd this latter view of tlic I-cactioii. So lorig as tlic organic ratliclc of the zinc-compound and that of tlic lmracic ctiicr arc idcriticid it is inipossilh to pve whcthcr tlic tlircc iiitlivitlrid atoms of ctliyl in boric etliide were originally pwsciit iii tlic 1wr:icic ctlicr or have ken derived from the zinc- ctliyl. Iii(1iwtiiig by an astcrisk tlie atoms of ethyl which finally bccorric part of tlic boric ctliiclc it is impossihlc to prove con-cliisivclp \vlietlicr tlic rcaction talccs place according to the first or the sccoiil of'tlic followiiig equations :-Althougli we cannot thus label as it were the atoms taking part in the reaction we can uiicrriiigly trace the movements of thc dcollol-~;icliclCs if we sccurc tlicir iilciitification by varying thcir composition in the two compounds used in the process.The study of tlic action of zincmcthyl upon horacic ether would obviously (lccidc 1)ctwccn these views. If boric etliide were pro-duccd fiwn tlicsc matcrials Kekul e's hypothesis n-odd be cstuhlislictl ; but if on tlic other hand boric niethide were the result of the reaction then the correctness of the view originally takcn by Mr.Duppa and myself would be proved to be correct. The folloiving are the results obtainedcin pursuing this inquiry Lehrbuch der org. Chemie p. 489. ORG Ah'I C COllPOU NDS CONTA ISING BONON. 373 Boric Methide. Whcn a strong ethcrcal solution of zincmethyl is added to boracic cthcr an 10" C. i's observcd whilst at the saine time a most intensely pungent- odour is developed ; this odoiir although it resembles that of hric ethide is far more pmvcrful and more persistently irritating to the mucous membrane. A slow evolution of a spon- taneously inflammahlc gas burning with a splendid green flame was also noticed; and this evolution of gas became more rapid when the warmth of the hand was applicd to the flask containing the ingrcdicnts.Prcliminary experiments proved that this gas was nearly insoluhlc in water but almost completely solul)le in .. alcohol the residue remaining undissolved being marsh-gas derive51 from the action of thc alcohol upon traces of zincrnetliyl vapour with which the gas was contaminated. l'hc gas was not condcnsed by a freezing mixture of ice and salt. It was with the excqtion of a small percentage of marsh-gas instantaneoudy dissolved hy solution of ammonia which yielded the gas again unchanged wlicn neutralized by ail acid Concentrated sulphuric acid was withuut action upon the gas. These data led to the following plan for collecting the gas in a state of purity. About two ounces of boracic ether were mixed in a small flask with rather more than their own bulk of an ethereal solution of zincmethyl of such strength as to be spon-taneously inflammable in a high degree.The flask loosely corked was placed in ice-cold water and allowed to stand for a couple of honrs until the reaction mas complete it was then furnished with a bent tube passing through a cork and designed to conduct the gas into a second flask placed in a freezing mixture of ice and salt; from this flask the gas passed into a third containing about half an ounce of strong solution of ammonia. The air in the whole of the apparatus was now displaced by nitrogen and the flask containing the boracic ether and zincmethyl removeu from the ice-cold water. A slow evolution of gas immediately commenced and was kept up at a convenient speed by plunging the generating flask into cold water to which heat was rery slowly applied.The gas in passing through the freezing mix-ture deposited nearly the whole of the ether and zincmethyl or 8' temperature to the cxtcnt of ofclcvation 374 FRANKLAND ON A NEW SlCRIES OF vapour with which it was contaminated; and on reaching the sollition of ammonia the boron- compound was instantaneously absorhcd whilst other gases if present passed through the aniirioiiia unacted upon and escaped into the atmosphere. The solutioii of ammonia soon became covered with a stratum of a lighter liqiiid which increased in quantity until the stream of gas ceascd to pass through. The ammonia-flask was now discon- nectcd with the rest of the apparatus and reserved for the next operation.The residue in the gencrating flask solidified to a crystalline mas8 on cooling. It now only remained to disengage the gaseous boron-compound from its combination with ammonia. For this purpose the ammonia-flask was fitted with a funnel-tube terminating beneath the surface of the liquid and a gas-delivery tube the latter leading to a Liebig’s potash-apparatus charged with concentrated sul- phuric acid ; finally the opposite extremity of the latter apparatus was connected with a mercurial gas-holder. To prevent dangerous explosions on the elimination of the spontaneously inflammable gas from its amrnonia-compound the whole of the air-spaces of the apparatus were filled with nitrogen. Everything being thus pre-pared dilute sulphuric acid was gradually poured into the ammo- nia-flask through the funnel-tube the contents of the flask being frequently agitated.No gas was evolved until the excess of ammonia was saturated ;then however it was given off abundantly and the addition of a few drops of dilute sulphuric acid from time to time through the funnel-tube served to keep up a con- venient current. The gas was allowed to pass freely through the depressed mercurial gas-holder until a sample of it proved by its perfect solution in ammonia that all nitrogen had been stvcpt from the apparatus. The exit-tube of the gas-holder was now closed and the gas collected in sufficient quantity for subsequeut experiments. The following determinations together with the analysis of its ammonirr-compound prove that this gas is boric methide aud that its formula is An indefinite quantity of the gas was cautiously led over ignited oxide of copper the carbonic acid and water produced ORGANXC C0MPO'I;NDEI CONTAINING BORON.375 being collected and weighed in the ordinary manner. 0.5875 grm. of carbonic acid and 03664grm. of water were obtained. These numbers show that the atomic relation of carbon to hydrogen is as 2 3. A determination of the specific gravity of the gas gave the number 1*9108--coinciding closely with the calculated specific gravity of boric methide which contains 1 volume of boron vapour and 3 volumes of methyl the four volumes being con-densed to two. 1 vol. boron vapour . . 075319 3 vols.methyl . . 3.10956 1.93137 Boric methide is produced from boracic ether and zincmethyl by the following reaction :-Boracic ether. Zincmethyl. Boric Ethylat e methide. of zinc. The formation of boric methide under these circumstances proves conclusively that the corresponding ethyl-compound is formed not by the removal of the whole of the oxygen from boracic ether but by the actual substitution of the three atoms of oxygen in boracic acid by three atoms of ethyl whilst boric methiiie is in like manner produced by the similar substitution of methyl for oxygen,-a kind of substitution which is quite in harmony with the mode of formation of very numerous cbmpounds in the organo- metallic family. Boric methide exists at ordinary temperatures as a colourlesa and transparent gas possessing a peculiar and intolerably pungent odour irritating the mucous membrane and provoking a copious flow of tears.Its specific gravity is 1.93137. It retains its gaseous condition when exposed to 8 cold of -16" C.; but at 10"C. and under a pressure of three atmospheres it condenses to a colourless transparent and very mobile liquid. It is very 376 FRANKLAND ON A NEW SERIES OF sparingly soluble in water but very soluble in alcohol and in ether. In contact with atmospheric air it takes fire spontaneously burn- ing with a bright green flame which is very fuliginous if the volume of the flame be considerable. If the gas issue into the air through a tube &th of an inch in diameter the amount of smoke is surprisingly great two or three cubic inches of gas when con-sumed in this may filling the atmosphere of a capacieus room with large comet-like flocks of carbonaceous matter.This curious phenomenon is probably due in part at least to the formation of a superficial coating of boracic acid which envelopes the particles of carbon and prevent3 their combustion. Suddenly mixed with atmospheric air or oxygen boric methide explodes with great violence. In contact with air both boric methide and the vapour of boric ethide exhibit two distinct kinds of spontaneous com-bustion. Thus when these bodies issue very slowly from a gless tube into the air thej burr1 with a lambent blue flame invisible in daylight and tlie temperature of which is so low that a finger may be held in it for some time without much inconvenience.Under these circumstances partial oxidation only takes place and it is to the 'products thus formed that the peculiar pungent odour of boric ethide and boric methide is due. When on the other hand these bodies issue into the air more rapidly the lambent blue and nearly cold flame changes to the green and hot flame above-mentioned. I have not examined the spectra of the two differently coloured flames from the same compound but they donlhless present a widely different appearance thus affording another instance of the dependence of the spectra of bodies upon temperature,-a pheno-menon to which Dr. Tyndall and myself recently called attention in the case of lithium*. Boric methide is not acted upon by binoxide of nitrogen or by iodine.Solution of bichromate of potash scarcely effects it but the addition of concentrated sulphuric acid at once determines the reduction of the chromic acid. When boric methide is allowed to bubble through water into chlorine each bubble burns explosively with a 6right flash of light and the separation of carbon. It has no tendency to unite with acids. Concentrated sulphuric acid has no action upon it ; when mixed with hydyiodic acid gas it suffers no change; but on the other hand it is freely absorbed by solu- tions of the fixed alkalies and by ammonia. If a very rapid cur- * Philosophical Magazine [4] xxii 472. ORGANIC COJfPOUNDS CONTAINING BORON. 377 rent of the gas mixed with half its volume of marsh-gas be passed through a stratum of strong solution of ammonia only half an inch deep not a trace of boric methide escapes absorption.Ammonia-Boric Methide. When dry ammoniacal gas is mixed with an equal volume of dry boric methide both gases instantly disappear with evolu- tion of a considerable amount of heat and production of a white volatile crystalline compound. The latter is also formed when boric methide is passed into solutiop of ammonia. The colourless liquid stratum which forms upon the surface soon solidifies when it is placed over sulphuric acid in vacuo. A quantity of the com- pound obtained by this latter process was purified 'by solution in ether and subsequent recrystallisatiou. On beiug submitted to analysis it yielded results agreeing with the formula-Ammonia-boric methide is deposited from its ethereal solution in magnificent arborescent crystals which rapidly volatilize without residue when exposed to the air.They possess a caustic and bit-ter taste and a very peculiar odour in which both the smell of ammonia and of boric methide can be recognised. Ammonia-boric methide fusea at 56"C. and boils at about 110" C. In a cur-rent of air or better of carbonic acid it sublimes at a very gentle heat and condenses in magnificent arborescent crystals. Deter-minations of the specific gravity of its vtipour at three different temperatures gave the Dumbers 1.251 1.258 and 1.250,iudicating that the vapour of ammonia-boric methide consists of equal volumes of boric methide and ammonia united without condensation :-1vol.Boric Methide . . 1.93137 1 vol. Ammonia . 05873 2)2*51867 1.25933 Thus the formula of ammonia-boric methide is a four-volume formula,* a state of condensation which is usually considered to 378 FRANKLAND ON -4 NEW SERIES OF be abnormal and which when it oeciirs is generally explained by the assumption of a. decomposition of the body at thc moment of conversion into vapour. The proof of the disunion or integrity of the valjorous molecule of ammonia-boric methide would be interest- ing in connexion with these so-called anomalous vapour-densities but I liave to regret my inability to offer any sufficiently cledisive solution of this problem. The difficulty to be overcome is the finding of a reagent that will not decompose ammonia-boric methide at elevated temperatures but which would absorb ammonia only out of a mixture of this gas with boric methide at a tem- perature above the boiling .point of ammonia- boric methide.Chloride of calcium does not decompose ammonia-boric methide ; but although it readily absorbs ammonia at ordinary temperatures it allows the whole of it to escape at 110' C. Chloride of zinc decomposes ammonia-boric methide before the latter volatilizes. The same effect is produced by all the strong acids which are therefore also inadmissible whilst dry boracic acid does not absorb ammonia even at ordinary temperatures. The substance which appeared to be best adapted for this reaction was dry and recently fused chloride of copper.This salt doespot decompose ammonia- boric methide below the boiling point of the latter whilst it readily absorbs ammonia and retains it at a temperature of 160" C. .I will now describe the mode in which an experiment with this substance was conducted and the results which were obtained. A quantity of ammonia-boric methide was introduced into a graduated tube filled with m&eury and inverted in a vessel containing the same metal. The whole was now immersed in an oil-bath and heat applied until the boron-compound was converted into vapour the volume of which at a known temperature and pressure was then observed. After the apparatus had been allowed to cool a frag-ment of chloride of copper was passed up into the tube,-.and heat again applied.The boron-compound soon melted and enveloped the fragment of chloride of copper as the temperature approached the boiling-point r>f ammonia-boric methide; the latter slowly boiled off from the chloride of copper and the vapour then occupied the same volume as that read off before the introduction of the chloride of copper. The mercury in the tube remained steady for two or three minutes; it then gradually ascended and the contraction of the vapour-volume continued until it was reduced to exactly one- half as indicated by the following numbers :- ORGANIC COMPOUND8 CONTAINING BORON. 379 Corrected volume of vapour before treat- ment with chloride of copper . . 35-67 cub. centims. Ditto after treatment with chloride of copper .. 17.85 cub. centims. By treatment with chloride of copper 100 volumes of vapour were therefore reduced to 50.04 vols. and the residue consisted of pure boric methide gas. It is obvious that this absorption may be due either to decomposition of the vapour of ammonia-boric methide by ci7rloride of copper tlt an elevated temperature or to the decomposition by heat of the boric colnpound into cqual volumes of boric methide and ammonia the latter being then absorbed by the chloride of copper. Unfortunately the result ofthe experiment is not sufficiently decisive to compel the adoption ofeither of these hypotheses although the formation of the vapour and its existence for a few minutes in contact with chloride of copper favour the first more than the second ; thus indicating that the vapour of ammonia-boric methide consists of equal volumes of ammonia and boric methide united without condensation a result which would harmonize with the very generally observed rule that when two gases or vapours unite in equal volumes the volume of the compound is equal to that of its constitucnts.Ammonia-boric methide scarcely absorbs a perceptible amount of oxygen at ordihary temperatures even after several days' exposure to the gas ; but it takes fire below 100' C. when hcated in contact with the air. Its vapour is also very inflammable ;thus when ammonia-boric methide is placed under the receiver of an air-pump and the air is being withdrawn the explosion of the mixture of air and vapour in the cylinders of the pump is fre-quently determined by the rise of temperature consequent upon the depression of the pistons when the rarefaction has become con- siderable.Boric methide is also absorbed by aniline with great avidity. A ids expel the gas from this compound unchanged. Terhydiide of phosphorug has no action upon boric methide. A mixture of equal volumes of the two gases is spontaneously inflammable burning with a yellowish-white flame in which the characteristic green tinge attending the combustion of boric methide is no longer perceptible. Compounds of Boric Methide with Potash Soda Lime and FRANELAND ON A NEW SERIES OF bury la.-Solution of caustic potash absorbs boric methide with great encrgy.The saturated solution exposed over sulphiiri c acid in vacuo dries down to a gummy mass which scarcely exhibits signs of crystallisation. The same body may be more conveniently formcd by decomposing ammonia-boric methide with alcoholic solution of potash taking care to employ an excess of the former. On evaporation over sulphuric acid in vacuo the excess of' the ammonia-compound volatilizes and is decomposed by the sulphuric acid with elimination of boric methide thus the potasli-com- pound evaporates in an atmosphere of boric methide. Nevertheless even by this method I did not siiccecd in obtaining the potash- compound in a state of purity potash-boric methide thus pre-pared yielding on analysis -1+7-03 per cent. of potash and 42.86per cent.of boric methide numbers only very remotely indicating the formula KO.B(C,H,), which requires 45-67 per cent. of potash and 54.33 pcr cent. of boric methide. The appearance of the compound even aftcr exposure to gentle heat in racuo suggested tlie presence of water which could not however he expelled at a temperature below that at which yotash-boric methide itself is decomposed. Boric methide is also readily absorbed by solution of neutral carbonate of potash; bicarbonate of potash and potash-boric methide being apparently formed. Although boric methide and potash unite with remarkable energy yet they are separated by acids with the greatest readiness; even carbonic acid in the presence,of water can expel boric methide from its potash-com- pound; thus if an aqueous solution of potash-boric methide be passed into carbonic acid stailding over mercury the acid gas soon hecomes feplaced by pure boric methide.Soda-boricmethide baryta-boricmethide and lime-boricmethide are similar bodies produced by the absorption of boric methide gas by caustic solutions of soda baryta and lime; they are all readily soluble in water and react alkaline. Boric methide in combination with the alkalies and alkaline earths has almost entirely lost its powerful affinit.y for oxygen ; nevertheless when these bodies are placed in contact with a known quantity of oxygen over mercury for several days the volume of the gas perceptibly diminishes. The great difficulty not to say danger attending the gradual ORGAKIC COMPOUNDS CONTAINING BORON.oxidation of considerable quantities of a gaseous and spontaneously inflammable body like boric methide has prevented me ffom followiiig this compound into its products of oxidation as was done in the case of boric ethicle. With a graduated supply of osygen however boric methide appears to comport itself like boric ethide and the compounds formed are probably homologous with diethylate and dihydrate of boric dioxyethide. In conclusion it can scarcely be doubted that the action upon lmracic ethcr of the ziric-compounds of the remaining alcohol- radicles woiild produce thc homologues of the bodies described in the foregoing pages. It may also be remarked that the exist- ence of bodies like boric dioxycthide in which one-third of the oxygen in boracic anhydride is replaced by ethyl altogether abolishes any supposed analogy bet ween carbonic and boracic acids whilst it proves that the composition of the latter acid is expressed by the formula BO, or some multiple of that formula.I am at present engaged in studying the action of' zincethyl and sodium-ethyl upon the ethers of silicic carbonic oxalic and acetic acids.

ISSN:0368-1769    

DOI:10.1039/JS8621500363

出版商:RSC    

年代:1862

数据来源: RSC

摘要:

ORGAKIC COMPOUNDS CONTAINING BORON. 381 XLVII.-On a Method for the Determination of Nitric and Nitrous Acids. HAILCOURT, BY A. VERNON M.A. Studentof Christ Church Oxford. INthe course of some experiments upon the alkaline peroxides* I had occasion to determine the quantity of nitrogen in a mixture of nitrate and nitrite of potassium. Finding no account of a method suitable for this purpose I was compelled to seek one experimentally. That at which I arrived and which is briefly indicated in the paper referred to gives very exact results and promises to be available for the determination of any nitrate or nitrite whatsover and however admixed. Since that time a method has been published by Professor * Journ. Chem. SOC.,vol. 16 p. 289. VOL xv IS 382 A..VERNON EIARCOURT ON A METHOD FOR THE Sc h ul z e,* differing only in one important particular the employ- ment of plathized zinc in the place of zinc and iron from that pursued by me. A brief account of this latter method and its results may however still be acceptable. It has long been known that when nitre is heated with an ex- cess of potash zinc and water ammonia gas is evolved. But the conversion effected in this way is "incomplete. In a number of experiments made with the view of founding a quantitative method upon this reaction the ammonia thus formed was collected and determined; it amoiinted to about jths of that quantity which the weight of nitre used was theoretically capable of yield-ing. No modification in the proportions of.zinc and potash solu- tion or in the degree of concentration of the latter materially improved this result. Under no conditions was the relation suffi-ciently constant to furnish an empirical number. Nitre heated in a combustion-tube with a mixture of powdered zinc and soda- lime yielded only a trace of ammonia. Jt was observed I believe by Mr. Griffin,t that when a moderately concentrated solution of potash is poured upon a mixture of zinc and iron hydrogen is freely disengaged even without the application of heat. This action is electro- lytic ; the zinc is oxidized and the hydrogen formed upon the surface of the iron. A similar effect is observed if platinum copper or tin be substituted for iron; but the action with these metals is less energetic.The addition of a nitrate to the mixture evolving hydrogen is followed by an immediate development of ammonia. This reaction furnishes a good qualitative test of the presence of nitric or nitrous acid. The fluid to be examined is reduced to a small bulk and poured into a test-tube containing two or three grammes of a mixture of granulated zinc and clean iron filings. A small quantity (5 or 6 c.c.) of strong potash soh- tion is added and the whole heated to boiling. The usual tests for ammonia may be applied at the mouth of the tube *005 grm. of nitre thus treated gave a distinct reaction with reddened lit- mus paper. The employment of potassio-iodide of mercury renders this test far more delicate. The mixture should be gently boiled for five or ten minutes and the evolved gases led into a small quantity of dilute hydrochloric acid.The acid solution is * Chem. Central Blatt No. 53. + QrifRn's Chemical Recreations p. 231. DETERMINATION OF NITBIC AND NITBOUB ACID& 383 is supersaturated with potash and tested with a drop of potassio. iodide of mercury *001 *0005,and even *OOO1 grms. of nitre gave a distinct red coloration when thus treated. The apparatus which I havc employed for quantitative deter-minations ia represented on a scale of +th in the following figure. The flask a which has a capacity of 200C.C. is designed for the generation of ammonia by the mutual action of*nitric acid zinc iron potash and water. It is connected by a bent tube drawn out and recurved at its extremity with the smaller flask or bulb b; and the two are so arranged that they both rest at a considerable angle of inclination upon the sand-bath c.The smaller flask ia connected with a condenser which leads into the tubulated receiver d. In the upper part of the condensing tube is a small tubuluref closed during the distillation by a plug of india-rubber. The tube e which is provided with two or more bulbs and a funnel-head has the shape indicated in the figure. It is fastened into the tul)ulure by means of a perforated plug of caoutchouc which whcn slightly greased makes a tight and supple joint. A stanclard solution of sulyhuric acid is used for the collection and deter-mination of the ammonia. The excess of acid employed is filially determined by means of a standard solution of caustic potash.The following is the course of the operation :-The funnel-tube e is brought into a vertical position bj being turned round in the tuhulurc through half a circle; a quantity of staiidard acid from a hurctte is passed through it into the receiver more than enough to ncutralize all tlic ammonia that can be formed. Some litmus 384 A. VERNON IiAllCOURT ON A METHOD FOR THE eolution is added to render visible the progress of the action. The funnel-tube is then restored to a horizontal position and its bulbs filled up to the proper level by a few drops more of the standard acid. The total qriantity of acid that has been taken is now read off upon the hrctte. The flask a is then removed its tulw and cork togctlier with the sinaller flask which should con- tain a little water remaiuing in position upon the sand-bath.Into it is introduced about 50 grms. of finely granulated zinc toge- ther with half that quantity of iron filings which have been cleansed by sifting and ignition in B covered crucible ; a weighed portion of the nitrate to be determined is then introduced with water sufficient to dissolve it ; lastly a measured quantity of a solution Df caustic potash free from nitre is added and the flask immediately replaced. It is essential that the quantity of the metals aDd of the potash ctnploycd should greatly exceed that proportion which is thcorctically necessary for the complete conversion of the nitric acid.In my experiments with nitre I have generally taken about 0.5 grm. of that substance 20 C.C. of water and 20 C.C. of a solution of potash sp. gr. 1.3. Provided the quantity of potash be sufficient it is immaterial in what degree its solution is diluted since in the course of the distillation it passes through every stage of eonccntration. It must not be highly concentrated at the commcnccrileiit of thc opcr a t’ ion. Heat is now ilpplid to the part of the sand-bath immediately beneath the larger flask and tlie fluid is gradually raised to the ?)oiling poiiit. If thc buhhles of air and hydrogen pass at a mocleratc rate through the hlb-tuhc e there is no risk of a loss of ammonia. When distillation has commenced the lamp is so placed that the water in the sma’rler flask 7) may also boil gently.Tlie fluid is thus twice distilled iii one operation and tlic traces of potash which escape from the flask a arc effectually retained in tlie flask b. The end of cnch of tlic two exit-tubes is drawn out and hent into a hook for furtlier security. liepcnted experiment has proved tlie sufficiency of this arrangemciit for keeping hack in a slow distillntiou evcrything that is not volatile. The quantity of fluid in the flask b can be regulated by adjusting the position of the lamp. The distillation which should occupy from onc to two hours requires only occasional attention. Tt may be termi- nated when hydrogen gas wliich is evolved in larger quantity as the potash becomes conccntratctl lips becn passing regularly for five or ten iinutcs through the bulb-tube e.When the fluid in e DETERMINATION OF NlTRlC AND NITROUS ACID. 385 has receded as the apparatus cools irito the inner bulb the caout-chouc plug is withdrawn from f,and a stream of water poured into the condensing tube to prcclude the possibility of ammonia being retained upon any portiori of its surface. 'I%e tube e ie then turned round iiito the vertical position and water is passed though it two or three timcs afier which it is removed and the tuhulure of the receiver closcd by a cork. Finally the receiver itdf is diuconnecterl the cml .of the condensing tube is rinsed externally and the determination is completed by adding standard alkali from a burette to the fluid in the receiver till a change of colour appears; Collection in hydrochloric acid and precipitation by choride of platinum may he substituted but the volumetric method gives perfectly sharp results.The zinc and iron which remain in the generating flask need only to be washed with water with dilute acid and again with watcr to he ready for a second determination-. Metals that hare once bcen used gcnerate hydrogen far less actively than zinc with a bright surface and freshly ignited iron; but the production of ammonia proceeds as readily with one as with the other. It may he safely assumed that the presence of any salts which are without action upon caustic potash or upon zinc RIA^ iron will riot interfere with the reaction upon which this method depends.The experiment mas however made of mixing weighed quantities of riitrc with various proportions of sulphate of potassium and chloridc of sodium. The presence of these salts did not affect the result. For the estimation of nitric acid in other than alkaline nitrates the separation of the base may in some cases prove a necessary A. VERNON HARCOURT ON A METHOD &C. preliminary. I have cxperirnented only with nitrate of barium and nitrate of lead. The former may be' determined exactly in the same way as nitrate of potassium and with equally good results. The carbonate of barium which separates on adding solution of caustic potash is as might be expected without influence on tbe reaction. Nitrate of lead exhibits a slight defi- ciency when thus directly determined.In five experiments in-stead of 8.45 per cent. of nitrogen the following numbers were found-7.78 7-83 8-09 8.28 8.11. This deficiency is possibly due to an action of dissolved oxide of lead upon the surface of the zinc. It would certainly disappear if the lead were first sepa- rated by means of sulyhate of potassium. A few examples of determinations made by this method are given in conclusion. A solution of pure nitre was made and of this 10 C.C. were used in each experiment. This quantity evaporated to clryness left a rcsidue wcighing 0.3838 grm. 1 C.C. of the standard acid employed neutralizes an amount of ammonia coritainihg 0.002084 grm. of nitrogen. In six consccutive expcrirnents the number of C.C. of this acid rcquircd was- (1).25.7 -(2). 25.3 (3). 25.3 (4). 25.4 (4). 25.4 (6). 25.6 of which the mean is 25.45 c.c. hence the total nitrogen found is 0.05304 grm.; the nitrogen per cent. 13.82; theory requires 13.86. In eight consecutive experirncnts made with the same standard acid thc quantity of nitre taken for each was 0.4986grm. The number of cubic centimetres required was,-(1). 33.15 (2). 32.9 (3). 33.1 (.%).33.2 (5). 33.05 (6). 33.1 (7). 33.15 (8). 33.2 of which thc mean is 33.1 liencc thc total nitrogen found is O*OG'$ ; the nitrogen per cent. 13-83.

ISSN:0368-1769    

DOI:10.1039/JS8621500381

出版商:RSC    

年代:1862

数据来源: RSC

摘要:

W'IJRTZ ON OXIDE OF ETIIYLENE ETC. XLVIK-On Oxide of Ethylene considered as a link between Organic and Mineral Chemisty. [A Discourse delivered to the Fellows of the Chemical society of Lqkdon June 5th 1862.1 BY I$. AD. WUBTZ. TN the year 1795 four Dutch Chemists Deiman Troostwyk Bondt and Lauwerenburgh first made the remarkable experi- ment of bringing together equal volumes of chlorine and olefiant gases whereby they obtained a liquid compound still known by the name of "Dutch liquid." This compound is an organic chloride the dichloride of the diatomic radicle olefiant gas or ethylene; and its constitution or rather its mode of formation and most of its chemical properties show that it may be represented by the formula Oxyde of ethylene is the corresponding oxide- This oxide cannot be formed directly by the action of oxygen on ethylene,* but it is obtained as a derivative of glycol of which it is the anhydride or ether.I must here draw attention to the re-actions by which glycol is produced for they exhibit a remaskable peculiarity on which I must especially insist. I obtained this body by the action of potash or baryta on diacetic glycol a compound produced by the action of bromide or iodide of ethylene on acetate of silver aa shown by the following equation :-Here we see clearly that 2 atoms of silver are removed and their place supplied by ethylene which thus as it were rivets I have in vain endeavoured to bring about the direct combination of oxygen and ethylene by heating a mixture of the two gases in the required proportione in a sealed flaskcontaining acetic acid.I hoped to obtain by this method the acetate of ethylene or acetic glycol. WURTZ ON OXIDE OF ETHYLENE ETC. together the residues of the two molecules of acetate producing diacetic glycol. Polyatomic radicles are indeed especially cha- racterised by the power which they possess of partially encroach- ing on several molecules belonging to a simple type and thus joining these molecules together so as to form a more complex type. Glycol itself for example may be supposed to result from the substitution of ethylene for 2 atoms of hydrogen in two molecales of water thus rivetted together :-I rniist not omit to notice here that the general idea just enunciated was first suggested by Professor William son,* when he represented sulphuric acid as derived from two molecules of water in which two atoms of hydrogen are replaced by the radicle sulphuryl H H H2] 432 but I believe myself justified in adding that my own researches on the glycols have afforded a tangible representation and .as it were an experimental demonstration of this idea and have served to establish the notion of poly atomic radicles in organic chemistry.Glycol cannot be dehydrated directly so as to transform it into oxide of ethylene. This transformation is however effected indirectly by first subjecting glycol to the action of chlorhydric acid which expels the water and forms chlorhydric glycol and by then treating this body with caustic potash- + G2H4Q.H2Q HC1 = C2H4Q.HC1 + H28 C2H4B.HC1+ KHQ = G,H4Q+ H,Q + KC1 On adding caustic potash to chlorhydric glycol or chlorhydrate of oxide of ethylene an immediate precipitation of chloride of potassium takes place accompanied by violent evolution of gas.This gas conducted into a cooled receiver condenses into a light transparent mobile liquid which is oxide of ethylene. This compound boils at 13.5". It is miscible in all proportions with water and with alcohol. Like the isomeric body aldehyde it reduces nitrate of silver but more slowly. * Chem. SOC.Qu. J. iv. 350. WURTZ ON OXIDE OF ETHYLENE ETC. Oxide of ethylme is a very plastic compound,. which is capable 04 uniting directly with a host of bodies with hydrogen to form rilcohol ;with oxygen to form glycolic acid ;with bromine forming red crystals coiisisting of a bromide of oxide of ctliylcne having the composition 2C2H4Q,Br? ;with water to form glycol and the polyethylenic alcohols ; and lastly with ammonia to form oxygenated bases.These properties taken together show that oxide of ethylene is analogous to certain oxides belongiqg to the domain of mineral chemistry. To bring out this analogy by the comparison of its constitution and re-actions with those of the mineral oxides in question is the object of the present lectrire. In the first place the basic properties of oxide of ethylene may be demonstrated by a very striking experiment. If a concentrated solution of chloride of magnesium be introduced into a flask together with oxide of ethylene the flask then sealed and the whole left to itself for about 24 hours ail abundant deposit of hydrate of magnesia is produced while chlorhydric glycol (chlorhydrate of oxide of ethylene) remains in solution.The oxide of ethylene has consequently displaced the magnesia ;and in tike manner it displaces alumina ferric oxide and cupric oxide. It behaves therefore like an oxide and accordingly we represent it as an oxide expressing its composition by the formula (‘2H 4) ’lo in which the ethylene plays the part of a diatomic radicle. The question now arises Do radicles of this nature exist among the metals and are there any metallic oxides which can be compared as to their constitution with oxide of ethylene ? With the view of obtaining an answer to this question we shall compare with oxide of ethylene the oxides of barium strontium calcium magnesium manganosum ferrosum zinc copper lead mercury 4c.representing them by the formulae In these formulz the metals are regarded as diatomic and as possessing atomic weights double of those which are commonly assigned to them thus becoming analogous to ethylene so far if8 regards their combining capacity But are we justified in doubling the atomic weights of thcse metals ? We shall endeavour WURTZ ON OXIDE OF ETHYLENE ETC. to show that this view is supported by facts relying in the first place on certain physical proofs and afterwards adduciug a certain number of arguments drawn from chemistry itself in favour of the opinion that we have adopted.It is right to add that the notion of polyatomic metals was introduced into chemical science by Dr. Odling and that the idea of regarding the metals above- mentioned as diatomic and doubling their atomic weights was first conceived by M. Cannizzaro. Observe in the first place that the atomic weights in question are the same it9 those of Berzelius. This will be seen from the following table :-Berz el isn Atomic Weights. Names of the ieferred to 100 Referred to 1 Cte rhardt's New Atomic Elements. of Oxygen. of Hydrogen. Ltomic Weights Weights. Hydrogen .... 6-25 1 1 1 Oxygen ...... 100 16 16 16 Sulphur ...... 201.16 32.2 32 32 Chlorine ...... 221:3 35.6 35'5 35'5 Bromine ......499.8 79.8 80 80 Iodine ........ 792.99 126.8 127 127 Nitrogen.. .... 88.5 14.1 14 14 Phosphorus.. .. 196 31.5 31 31 Arsenic ...... 469.4 75-1 75 75 Carbon. ....... 75.12 12 12 12 Silicium ...... 277.7 44.4 ; 28 24 (which = 208f) Tin .......... 135-119 117.6 58-75 118 Barium ...... 865.29 136.8 68 136.8 Strontium :.b . 546.9 8'1.3 43.8 87.3 Calcium ...... 251.65 40.2 20 40 Magnesium.. .. 158.14 25 12 24 Manganese .... 844.6 55.1 27.8 55.6 Iron.. ........ 350.5 56.1 28 56 Zinc. ......... 406.59 66 32.6 65 Cadmium .... 696.77 111.4 56-7 111.4 Copper........ 395.6 63.3 31.5 63 Lead;......... 1294.6 207 103.5 207 Mercury ...... 1251.29 200-2 100 200 --_I-Silver ........ 1351'6 215.6 108 108 Potassium ....489.9 78.3 39 39 Sodium ...... 290-9 46-6 23 23 Lithium ...... 81-60 13 6-5 6-5 It will be seen that the atomic weights in the second column are for a considerable number of metals double of those proposed by Gerhardt. It is these double atomic weights that are represented by the barred symbols of the preceding formulae which in fact are WURTZ QN OXIDE OF ETHYLENE ETC. identical with the old formulae of Berzelius :* for the bars which are perhaps necessary during the existing confusion of symbols are merely provisional and will ultimately fall into disuse. These double atomic weights are applicable to the diatomic metals above-mentioned but not to silver potassium sodium and lithium which are monatomic and comparable with hydrogen.With regard then to the metals included in the preceding table we adopt the atomic weights of Berzelius excepting for the last four metals which retain the smaller atomic weights adopted by Gerhardt. The new system of atomic weights accords better than any other with the physical data which serve to control the determi- nation of the relative weights of the. atoms. In fact the numbers in the last column are identicalewith those designated by M. Reg n ault as ‘‘therrnic equivalents.” This philosopher has observed that the law of Dulong and Petit according to which the specific heats of the elementary bodies are to one mother in the inverse ratio of their atomic weights presents but few ex-ceptions; and that even these disappear if we admit for hydrogen potassium sodium and silver equivalents half as great as those generally adopted,-that is to say if while we retain the usual equivalents of the other elements we assign to the four bodiee just mentioned the numbers & -728 %?- 9”.It is easy to see that the equivalents or rather atomic weights of this system are identical with those in the last column of the preceding table. According to the recent experiments of M. Regnault the specific heat of crystallized silicium forms an exception to the law of ’Duloiig and Petit but this exception may be attributed to a peculiar molecular constitution resulting from the allotropic states of this element for the former experiments of M. Regnault have taught us that among the several allotropic modifications of carbon there is but one viz, lamp-black whose specific heat satisfies the law in question,-whereas those of diamond and graphite the allotropic states of which are similar to those of silicium deviate from that 1aw.t In the next place the new system of atomic weights is in harmony with the law of isomorphism which requires that Benelius wrote BaO Bag BaO.H,O Baa BaS04 &c.We return to these formulae but we agree with Gerhardt in writing K20,KS,KHO KC1 K&30~ &c. f’ See on this point the impo’rtant remarks of Mr. Brodie on the atomic weight of graphite. Phil. Trans. 1859 p. 249. WURTZ ON OXIDE Ok' ETHYLENE ETC. isomorphous bodies be represented by analogous formulae. Thus ctiprous s~lphide which is isomorphous with sulphide of silver Ag,S is expressed in the new system by the formula Gu2S,whereas Gcrhardt assigned to it the formula Cu,S.Again the sulphates of silver arid of sodium are represented by the analogous formulae SAg,Q and SNa,O,. The isomorphous dphatcs of the mag-pesian series are expressed by the formula- SMO + 7H20.* The composition of the double sulphates of the same series is respresented by the forrnnla- SMO . SR,O + 6H20. Lastly the system of atomic weights which we adopt is in harmony with the vapour-densities of a very considerable number of bodies. The exceptions observed relate to the vapour-densities of iertain elementarj- bodies.? Thus the atomic weights of phos- A large number of salts contain quantities of water which in Gerhardt's notation must be represented by a fractional number of molecules (H,Q =18).NOW this inconvenience is obviated if we double the atomic weights of a certain number of thc metals as may be seen by the following examples .-Gerhard t's Notation. New Notation. NiCl + 4& H,8 N i"C1 + 9 H2Q '&' ]Q2 + 3 H2Q .t. The atomic weights of the elementary bodies (referred to 1volume) are obtained by multiplying their vapour-densities by 14.44 = .& ; and the molecular weights (referred to 2 volumes) are obtained by multiplying the vapour-densities by 28-88 = But on .multiplying the vapour-densities of mercury 6.9'76 and of cadmium 3-94 by 28.88 we find the numbers 201.4 and 113.7 ; and the anomaly exhibited by these metals may be expressed by saying that their molecular weights such as are deduced from their vapour-densities really repreeent their atomic weights (200 = &; 111:5 = 4%).On the other hand if we multiply the papour-densitiesof phosphorus 4-42 and of arsenic 10-6,hy 14-44 we obtain the numbers 63 8 and 153 an anomaly which may be expressed by eaying that the atomic weights of these bodies as deduced from their vapour-densities really express their molecular weights (PP = 63 ; .4s As = 150). WURTZ ON OXIDE OF ETHYLENE ETC. phorus arsenic mercury zinc and cadmium calculated from their vapour-densities do not agree with those which are deduced from other considerations. These cases may however be regarded as exceptional if we remember that the atomic weights of a large number of compounds into which these elements enter are in accordance with the atomic weights in question.We will cite a few examples confining ourselves to the diatomic aud tetratomic metals :-Molecular VSprrur-denaitiee. weighta de-duced from -I vapour-denaities. I Chloride of,ailicium . Chloride of zirconium 5.939 8-2'1 171 237 170 SiC1 Zr2C14 Chloride of titanium. Stannic chloride . . . Stannethyl. . . . . . Zinc-ethyl . . . . . .,Mercuric chloride . . Mercuric bromide . . 6.836 9.2 8.021 4259 9.42 12.16 197 265 232 123 271. 351 1902 260 234 124 271 360 TiC1 linC1 Sn (GIH5)*Zn(G,H,),SgC1 GgBr If then we adopt for the metals in question atomic weights twice as great as those usually assigned to them and accordingly regard the metals as diatomic we shall be able to compare oxide of ethylene with the oxides of these metals.' This organic oxide thus becomes the analogue of baryta just as oxide of ethyl is the analogue of oxide of silver and oxide of glyceryl the analogue of oxide of antimony.Ba"0 I. We know that caustic baryta is capable of abeorbing oxygen and passing to a higher degree 'of oxidation vie. the bioride of barium. Oxide of ethylene possewes the 8ame propefiy although the reaction takee place under different conditions and the pro- 3931 WURTZ ON OXIDE 01' E'I'IiYLENE E'I'C. duct instead of being neutral like bioxide of barium exhibits the properties of an acid. When an aqueous solution of oxide of ethylene is placed in contact with platinum-black the liquid rapidly becomes acid in consequence of the formation of glycolic acid which coiistitutcs the product of the direct oxidation of oxide of ethylcnc.Tlic glyoxylic acid of Dr. Debus may bc regarded as a higher oxide of the same products so that we may construct the following series :-. G2H4............. ethylene. G,FL,C) ............ oxide of ethylcne. GQtI4Q2............ glycolic acid. C2H,Q3............ glyoxylic acid. We are acquainted with other series of the samc kind in organic chemistry and these series bc it observed have their analogues in miiieral chemistry. Lnurent cstablishcd thc following series :*-................ PH3 C1H c1HC) .............. P€I& .............. YI-I3@3 C11TB2 Cl€[Cs ..............PII,c), ClIEC) .............. and Odling. developing this idea has given other series of the samc kind in his cxucellcnt "Manual of Chemistry." H. Caustic baryta to which wc ham just compared oxide of ethylenc unitcs directly with water to form hydrate of baryta. In like manner oxidc of ethylene is capable of fixing water so as to form hydrate of oxidc of cthyleric that is to say gl~vcol. Between the hydrates of organic chcmistry and the hydratcd oxides of miiicral chemistry me may cstablish the followiiig parallel :-Sb"' E) c II 103 Ftl."7 116 % Baryta. Potassa. y)a Antimonic hydrate. Ferric hydrate. (G 11 If3 1@3 )''I Alcohol. Hydrate of ethylene. Glycerin. ITexylic hydrate (glycol.) (Mannite.)t * Laurent's Methode cle Cliemie translatcd ljy Odling.pp. 30 31. t Wanklyn and Erlenmeyer Proceedings of tlic Royal Society xi.. 447. $ FfG = Fc' = 112. wuirrz ON OXIDE OF .ETHYLENE 1c-m But oxide of ethylene exhibits this remarkable peculiarity that not only is one molecule of it capable of uniting with one rnolccule of water but two,three four Jive or more inolccules of oxide of ethylene can combiue with a single moleculc of water to form hydrates belonging to morc and more complex types. These hydrates convtitutc thc polyethylenic alcohds the fimt of which viz. diethylenic alcohol was discovered by M. Lourcnqo. They may be regarded as resulting from the partia1,dehydration of an increasing number of moleciiles of glycol. Glycol. Diethyleoic alcoh01.Triethylenic alcohol. The study of these bodies establishes a new property of ethylene the power of accumulating in combination and thereby forming compounds containing multiple radicles and belonging to types of greater and greater complexity. This property is likewise possessed by other organic radicles. M. Friedel and myself have found it in acetyl which accumulatcs in the polyacetic com- pounds and M. Lourenco has observed it in glyceryl which in like manner is capable of forming polyglyccric compounds. It is thcrefore a general property of polyatomic radicles and ought to be found not only in certain mineral groups but likewise in the elements of mineral chemistry which are the representatives of these radicles. Arnoiigst mineral groups possessing the property in question we may mention su&#turyl chronu& and p?iosp?ioryZ .which may be supposed to exist in the following compound9 :- WURTZ ON OXIDE OF ETHYLENE ETC.(PO)',' Nordhausen Chromate of Py rophoephoric wlphuric acid. potassium. acid. Amongst elementary bodies which play thc part of polyrttomic radicles we shall here consider only tin and silicium both tetratomic and capable of forming polystannic and polysilicic compounds. 1. Stannic hydrate to which Mr. Graham has just called attention in his remarkable researches on dialysis cobtains and yields with loss of H@ a hydrate containing which is the stanriic acid dried in vacuo analysed by M. Fremy. The composition of the stannates is represented by the formula Metastannic hydrate according to M.Frem y contains within its molecule ti atoms of tin so that its composition is expressed by the formula At loOo it gives off half its water and is converted into a hydrate 5Sn" HI0 The metastannates are represented by the formula 5Sniv1 H,R,J 15' We see then that in metastannic hydrate and the metastannatcs a number of atoms of tin are accumulated in one and -the same molecule. The same property is exhibited by silicium in various silicic hydrates and ethers and in a very large number of silicates. This will be seen by a glance at the following WCJltTZ ON OXIDE OF E'i'HYLENE ETC. table iu which the formulae ranged on the same horizontal line afford examples of continually increasing condensation whilst those in the same vertical column represent the hydrates or rather anhydrides formed successively by the loss of a continually increasing number of molecules of water :-Normal ailieio Okkite.Rykolite. Leucite. Feh& (ortho-ether. Ch.) Olivine. DGpide. Diethylic Diethlyic silicate. &silicate. We see then that thia theory enablea us to conceive and even to predict the existence of a very large number of silicates and that it is not without reason that these compounds have received the WURTZ ON OXIDE OF ETHYLENE ETC. epithet poZysiZicic. Their constitution and the formulae which represent them are not always very simple and cannot be so in a great number of cases; but that which is really simple and rational is their mode of generation based on-the principle of the uccumu-Zation of po2yatomic radicles.This principle which likewise regulates the congregation of organic molecules appears to be capable of a great number of applications in mineral chemistry and is on this account well worthy of attention We may also notice the part played in the formation of these compounds by the successive dehydration of which hydrates coutaining poly- atomic radicles are susceptible. 111. Oxide of ethylene unites directly with acids forming sdts which constitute the ethylenic ethers or ethers of glycol. These reactions sometimes take place with great energy. Thus when oxide of ethylene is placed in contact with sulphuric acid combi- nation takes place attended with a hissing noise and great evolution of heat.By operating with caution and using an acid diluted with water a nearly neutral liquid may be obtained which remains in the syrupy state when evaporated. The com- bination of oxide of ethylene with acetic acid also takes place at ordinary temperatures producing monacetic or diacetic glycol according as one or two molecules of acid enter into the reaction :-Diacetic glycol may be formed directly by heating acetic anhydride with oxide of ethylene :-Under these circumstances then oxide of ethylene hehaves like a metallic oxide and may be compared in this respect with oxide of copper or oxide of lead When a single molecule of acetic acid acts upon oxide of lead the so-called bibasic acetate of lead is formed which may be compared with monoacetate of ethylene :- WURTZ ON OXIDE OF ETHYLENE ETC.Monoacctatc of (8o-cd cd) BiImic ethglcnc. acetntc of lcad. But when two molcculcs of acctic acid act upon a molcciilc of oxide of coppcr or oxidc of lead nmtrul ucetute.9 are forrricd comparable with ethyleiic diacctate :-Ethy I cnc Diacctatc of coppcr Diacctatc of lead diacctate. (Cristaux dc J'cnuB). (Sal Saturni ;wgar of lead But the analogy of all thcse reactions may be drawn still closer; for just as several molecules of oxide of copper or oxide of lead can unite with acetic acid so likewise may two three four or more molecules of oxide of ethylene combine with acctic acid to form polyethylenic acetates. A glance at the following formula will bc sufficient to show the analogy hctwccn thc basic salts formed by certain mineral oxides and thesc polyethylcnic acetates :-(62H,) " 1 %" 5 ri (G2H,Jf' Q3 c.)* + 3H,Q ghr' G2H3Q)2 F2H3Q)2 KO.Dieth ylenic Dicupricacetate. Nitrouo-nifrate of Icad acetate. (I'c 1i got '8 hib:i$ic hyponitrate of lead ). Gu," "3" cS4 + 3H,# (~2%442 I-Triethylenic acetate. Tricupric acetatc Triplurnbic (heated to 160'). acetate. These basic salts owe their existence aid formation to tlic tendency possessed by polyatomic radicles Iloth simple and com-pound of accumulating in combination.;. TVc are iiot acquairitcrl with any well-defined basic salts formcd hy the uiiion of 1110110-basic acids with the oxides of potassium sodium lithium and silver; and the pow'er of forming basic salts possessed by most other oxides may perhaps be altogether dcpmdcnt 011 tlic polp-atomic nature of their metallic radicles.The followiiig facts however exhibit this polyatomicity in a still clearer light :- WUETZ ON OXIDE OF ETHYLENE ETC. Oxide of ethylene possesses the power of uniting with two different monobasic acids. We are in fict acquainted with ethylenic ethers containing two different acid-radicles such corn-ponnde having been obtained by Dr. Maxwell Simpson and M. Lourenco. In like manner there exist metallic salts produced by the reaction of two different monobasic acids on a diatomic oxide or hydrate. From this point of view we may compare aceto-butyric glycol with nitro-acetate of strontium or baryta :-~NQ ~~~e In these compounds the diatomic radicles ethylene and stron- tium perform exactly the same function as the diatomic radicle of tartaric acid in Rochelle salt and the existence of the aceto- nitrate of strontium affords as strong an argument in favour of the double atomic weight of strontium as that which was deduced by Liebig from the existence of Rochelle salt for doubling the formula of tartaric acid.IV. Oxide of ethylene unites directly with chlorhydric acid. On mixing the two gases in equal volumes over mercury they instantly disappear just as ammonia gas disappears on being mixed with chlorhydric acid. The result of the combination is chlorhydrate of oxide of ethylene or chlorhydric glycol :-G2%) 8 or 6,H4Q.HC1 c1 Glycol.Yoncddorhy Chlorhydrate of dric glycol. oxide of ethylene. Is there in miheral chemistry any compound analogous to momchlorhydric glycol?. I am not acquainted with any well defined metallic monochlorhydrin but a sulphuric monochlorhydrin was discovered a few years ago by Professor Williamson :-Snlphuric wid. Siilphuric monochlorhydrin. * C. v. Hsuer J. pr. Chem.lxxiv 431. ::[ WURTZ ON OXIDE OF ETHYLENE ETC. 401 On thc other hand several well defined fluorhydrins are known viz. oxyfluoridcs or fluorides of oxides. Thus Berzelius ana-lysecl a well crystallised oxyfluoricle of copper and expressed its composition by the formda CuF1.CuO.E-10 which if we adopt the double atomic weights of oxygen and copper becomes Gu 8.HF1 Flnorhydrate of cupric oxide. It is easy to see that this compound is related to cup& hydrate in the same manner as monochlorhydric glycol to glycol :-02 Fl. Cnpric hydrate. Cupric monofluorhydrin. There exist condensed chlorhydrins corresponding to the ply-ethylenic alcohols. Diethylenic alcohol is capable of forming two chlorhydrins whose compoaition is represented by the fol-lowing formulae :-Diethylenic alcohoL Monochlorhydrin of Dichlorhydrin of diethylenic alcohol. diethylenic alcohoL The monochlorhydrin of diethylenic alcohol is obtained by heat-ing chlorhydric glycol with oxide of ethylene :-It is a liquid boiling at about 180". The dibromhydrin of d~-ethylenic alcohol is probably formed when oxide of ethylene is boiled for a long time with bromide of ethylene (unpublished experiments) :- WUILTZ ON OXIDE OF ETHYLENE ETC.This last compound may be compared with the bromides and chlorides of mineral oxides. It will be interesting to cstablish this analogy by a few examples. Hydrate of lime dissolvea in a solution of chloride of calcium arid the alkaline liquid when concentrated yields on cooling hydrated crystals to which H. Itose assigns the formula 3CaO.CaC1 + 1GHO. In our notation this formnla becomes 3C&.GaClq + 16112Q and may be written as follows :-c2H47 423 c3I)O + 1611@ which is analogous to '2H4 ' O3 4314 t GnJ c2H-4J c12 c12 Dichlorhydrin of tetrcthylcnic alcohol. Therc are also oxychlorides of lead posscssing an analogous con-stitution.Thus Mcndipite which is a well crystallised mineral contains 2gbQ.FbC1 = fb3Q2 Cl,. Atacamite is a hydrated oxychloride of copper composcd of 3CuQ.GuC1 = su@3 (21,. Other facts belonging to mineral chemistry may likewise be compared with the preceding. Thus the compounds formed when ferric oxide is dissolved in a solution of ferric chloride (and we know that it dissolves abundantly) are doubtless analogous to the chlorhydrins. On the other hand H. Rose has shewn that the solution obtained by treating stannic chloride with water pos- scsscs characters totally different from those which are exhibited by the chlorhydric solution of metastannic acid.* From the molecular constitution of this acid we may suppose that its chlorhydric solution contains a polystannic chlorhydrin.V. Dr. Maxwell Simpson has described under the name of glycolic chloraceten (aceto- chlorhydric glycol) a mixed ether of glycol which he has obtained by subjecting that body to the simultaneoust action of acetic and chlorhydric acids. This com- ' Pogg. AM. cv. 564. + Procccdings of the Royal Society ix 725. WURTZ ON OXJDE OF ETHYLENE ETC. pound contains (c2H4)” Y 42 ; or as it may be more simply 6%W c1 (G2H4)”’ 8 (,G,H,Q)’} C1. We are acquainted with certain mineral compounds of analo- gops constitution excepting that in place of acetpl they contain polybasic acid radicles. Thus Wagnerite and Apatite which are well characterised mineral species are fluophosphates of magne-sium and calcium to which we may assign the formulze P0,.3MgO + MgFl and 3(P05.3Ca0) + CaFl which in our notation become Pia&xrite.Apatite. Wagnerite and Apatite are in fact the phosphofluorhydrins of the hydrates And here we have occasion for an important remark. Ordinary phosphoric (pe)”’}Q3 requires to saturate it more than one H3 atom of magnesium (M$ = 24) but two atoms of this magne- sium which are equivalent to four atoms of hydrogen are too much for the purpose. Now Wagnerite contains exactly two atoms of magnesium; it would therefore be supersatmated if the fourth combining unit of the group %N€g”were not saturated by the fluorine. The same reasoning applies to apatite and to the calcium contained in it.We see therefore that in these com-pounds whose constitution appears so strange when regarded from the dualistic point of view the fluorine or the chlorine plays an important and necessary part. I may add that the presence of such a monatomic element in these co’mpounds furnishes an argu-ment in favour of the diatomicity of magnesium and of calcium. If magnesium were monatomic the fluorine would be useless; for 3Mg [Mg = 121 could replace 3H in ordinary phosphoric acid. But the magnesium or the calcium being diatomic and therefore 404 WUKTZ ON OXIDE OF E’I’HYLENE ETC. of even atomicity the presence of a monatomic element becomes necessary to fill up the uneven atomicity of the phosphoryl (PQ)”’.* Other compounds may likewise be regarded from this point of view.There exists a chlorophosphate of lead exactly analogous in constitution to apatite and we know that the phosphoric acid in this chlorophosphate may be replaced by arseuic acid. Gerhard t has analysed a mercurous nitrophosphate which contains a molecule of mercurous phosphate united with a mole-cule of mercurous nitrate. This compound represented by the formula Hg,O.NO + 3Hg,0.P05 + 2HO may be considered a kind of Wagnerite ill which the magnesium is replaced by mer-curosum [Sg = 4001 and the fluorine by nitrous vapour :-VI. Just as the diatomic radicle ethylene can join together two ,molecules of water when it takes the place of two atoms of hydrogen to form glycol so likewise is it capable of uniting two molecules of ammonia to form ethylene-diamine I do not intend to give in this place a general view of the ethylenic polyamines- for our knowledge of which we are indebted to the classic re- searches and rare sagacity of Dr.Hofmann-but merely to call attention to the analogy existing between these compounds and certain mineral polyamiues. Diatomic metals are capable of replacing ethylene in the dia-mines. Compounds of this kind are known and rational formulE for expressing the constitution of various metallic polyamines * My friend Dr. 0d 1 in g has called my attention to a salt described by Br i egl e b (Ann. Ch. Pharm. xcviii. 95) and represented by the formula 3Na0.P05 + NaFl + 24HO. Without attempting to deny that the existence of this salt may weaken the argument afforded by the constitution of Wagnerite in frtvour of the diatomicity of magnesium I will nevertheless observe 1.That the salt is very unstable being resolved by boiling into phosphnte and fluoride. 2. That it has not been found possible to form a corresponding salt of potassium. 3. That this salt is not strictly comparable with Wagnerite lnasmuch as it contains water of crystallisation We are indebted to M. Cannizzaro for another chemical argument in favour of the diatomicity of calcium and barium-namely that whereas there exists a quad-roxalate of potassium we are not acquainted with a quadrcixalate of calcium or of barium. In fact a single atom of hydrogen in two molecules of oxalic acid may be replaced by an atom of potaseium but not by an atom of diatomic calcium which is equivalent to two atoms of hydrogen.If then a portion of the hydrogen in two molecules of oxalic acid is repiaced by calcium or barium the result of the subatitu- tion can only be a bioxalate. WURTZ ON OXIDE OE ETHYLENE ETC. have lately been proposed by MM. W eltz.ien and Hugo Schiff. I shall consider in this place only the formulae given by Schi ff for thc cupric amines viz. :-Cupriconium. Amicupriconium. I double thesc formulz and supposc that in the cupric dia- mines the diatomic radicle copper joins togcthcr two molecules of ammonium just as ethylene does in ethylenic diammonium. therefore write the formulae of the cupric diamrnoniums as follows :-Ethylene-diammonium. Cupriconium. Diamicupriconium.Tetramicupriconium. Acetate of cupriconium. Sulphate of Tctramicupriconium (ammonio-sulphatcof copper). Besides the ethylene-bases we are acquainted with another class of hases called oxyethylenic. They are formed by the direct com-bination of oxide of ctliylene with ammonia. One two three four molecules of oxide of ethylene can unite with a single mole- cule of ammonia to form bases of greater and greater complexity and this combination takes place at ordinary temperatures ener-gcticallp and without elimination of water so great is the com-bining power of oxide of ethylene. It appears to me-and with tbis consideration I will conclude-that there exist in mineral chemistry hases analogous to the oxycthylenic bases. M. Millon discovered some ycars ago a remarkable base to which he gave the name of ammonio-mercuric oxide.It is formed by the action of ammonia on mercuric oxide. Its composition is usually repre- sented by the formula 3Hg0.HgH2N + 3H0 which trans- 406 WUILTZ ON OXIDE OF ElITYLENE ETC. lated into our notation independently of any hypothesis respect- ing the molecular arrangement becomes- fL-€€gQ.NH + H,Q; according to which nminonio-mercuric oxide would bc thc analoguc of dioxethylenamine-2(€,H48).NH,. According to the cxperinients of M. Millon this base can give off inore than one molecule of water in drying and when per- fectly dry contains 3HgO.HgN21F, or in our notation 3&€gB.&€gN,H,. Herc again me may pcrceive a certain analogy between thesc facts and those which are observed in organic chemistry; me know indeed that the oxyethylenic bases are con- verted by loss of water into vinplic bases.Such are the considerations which I lmve ventured to put for- wad on the analogies existing between organic and mineral compounds. I have endeavoured to follow out these analogies in the most various classes of bodies and to express them in the typical notation so well adapted to comparisons of this nature. I shall think myself happy if I have succeeded in impressing more forcibly on the minds of my auditors this truth which everybody is ready to enunciate but which few have undertaken to establish hy strict demonstration-namely that there is but one Chemistry and that the laws which regulate the constitution of Organic bodies apply with equal force to the compounds of Mineral Chemistry and Illineralogy.

ISSN:0368-1769    

DOI:10.1039/JS8621500387

出版商:RSC    

年代:1862

数据来源: RSC

摘要:

MARCET ON THE CHEMISTRY OF DIGESTION. 407 XL1X.-On the Chemistry of Digestion. LA Discourse delivered to the Fellova of the Chemical Society.] BY W. MARCET, M.D. F.R.S. Assistant Physician to the Westminster Hospital etc. BYthe chemical phenomena of digestion we mean those chemical changes which food undergoes in the stomach and intestines the ob- ject of which is to transform it into certain soluble substances on the onehand and into emulsions on the other; for under those conditions only can the food taken be absorbed ihto the blood-vessels and lacteals and thereby effect the purpose of nutrition. If from some circumstance connected with the nature of the ingesta or a vitiated state of the gastric arid intestinal secretions the meta- morphosis in question does qot take place what has been eaten will be voided more or less unaltered,-a fact of importance in a medical point of view.My attention has been directed for many years to the subject of the present discourse and I avail myself with pleasure of this opportunity of recording the valuable aid of my former assistant Dr. Frederick Dupr6 in a considerable portion of these inquiries. The stomach during the period of fasting contains a small quantity of mucus exhibiting a slight though decided alkaline reaction; this can be easily ascertained by testing the few drops of the ropy and frothy fluid obtained from the stomach of a dog having a gastric fistula or external opening in that organ. As soon as solid food is taken the stomach secretes in abundance a strongly acid fluid the gastric juice and the process of digestion commences.The action of the gastric juice on the contents of the stomach is generally considered as due to its acid constituent and to a substance called pepsin which it contains in very small quantity. It should be remembered however that every one of the constituents of gastric juice must have a share in its action on food; just in the same way as certain therapeutical agents such as minerd waters are possessed of medicinal properties partly on account af a special substance they contain and partly from the united influ- ence of the whole of their constituents. Owingto this circumstance 408 MARCET ON TliE CHEMISTRY OF DIGESTION. it is important when experimenting on gastric juice to use as far aspossible the secretion obtained from an animal such as the dog and avoid conducting the inquiry with a digestive fluid prepared artificially by mixing together a dilute acid and pepsin I invariably used in my researches the gastric juice of four dogs extracted from each animal through a gastric fistula with which it had been provided.The secretion was excited with hard-boiled car- tilage or soft bones. By this means I obtained from two dogs about a gallon of gastric juice; and a much larger amount could have been extracted within the same time had it been required. In order to determine the composition of pure gastric juice it would be necessary to excite its secretion by means of hard sub- stances perfectly insoluble in that fluid unfortunately under those circumstances as for instance when dogs are made to swallow pebbles the quantity of gastric juice secreted is but very small and barely sufficient for a chemical inquiry.It must be remembered that hard animal tissues such as cartilage or even bone are rapidly acted upon by gastric juice so much so that the fluid obtained from the stomach after the ingestion of these substances cannot be regarded as the pure secretion. The acidity of gastric juice may be considered as one of its characteristic features. It is remarkable that chemists and physiologists do not yet agree as to the nature of this free acid although from the investigations of Bidder and Schmidt Dr. Prout’s opinion on the subject now prevails and the acid substance is believed to be hydrochloric acid; the experiment which Bidder and Schmidt undertook in order to resolve the question was as follows :-“About 100 grammes of gastric juice were used to yhich nitric) acid and nitrate of silver we& added; the amount of chloride of silver obtained was determined which yielded the weight of the whole of the hydrochloric acid present.After the excess of nitrate of silver had been removed from the gastric juice by precipitation with hydrochloric acid the fluid was evaporated to dryness caxefully incinerkted and the weight of the bases determined ;the quantity of hydrochloric acid necessary to neutralize these bases was then calculated.” By so doing Messrs. Bidder and Schmidt obtained on the one hand the weight of the whole of the hydro- chloric present in gastric juice and on the other the weight of the hydrochloric acid necessary to neutralize the bases; and as they found that the total amount of hydrochloric acid present was MARCET ON TIIE CHEMISTRY OF DIGESTION.409 greater than was necessary to neutralize the bases they concluded that gastric juice ccntained some free hydrochloric acid. In order to decide whether there was any free acid in gastric juice besides hydrocliloric acid these enquirers determined the acidity of gastric juice with an alkaline normal solution and they found the amount of the base necessary for the neutralization of this free acid to be exactly or nearly equivalent to the quantity of free hydrochloric present which had been ascertained in the first part of the experiment ; they therefore concluded that the whole of the free acid of gastric juice is hydrochloric acid.Notwithstanding tEe apparent correctness of this method of inres-tigation the gastric juice of a dog on Tyhich I have experimented has appeared to me for the fol1owir:g reason to contain more or less of another acid besides hydrochloric acid. I happened to place some gastric juice in Graham's dialpser which was made to fl0a.t on distilled water. A4ftera time the secretion contained in tlie dialyser had lost certain of its immediate principles which had passed into the distilled water. At first the acid gastric juice geve an abundant precipitate with nitrate of silver but tlie bulk of the precipitate gradually diminished the li:*drochloric acid passing into the distilled water ; and finally after coagulating the albumin by heat and filtering the addition of tlie reagent failed to give even a traoe of a precipitate thereby shorring that the hydro- chloric acid had entirely found its way through the membrane.On tcstiag the fl:iid in the dialyser at that period of the experiment it exhibited a' distinctly acid reaction ; consequently the gastric juice was still acid although it did not contain a trace of hydrochloric acid showing that another acid mas present besides the hydrochloric acid. Theacidity of gastric juice according to Bidder and Schmidt ranges from 0*1708 to 0.335396 of hydrochloric acid. I have had frequent opportunities of testing the degree of acidity of this secretion and have found it to correspond to between 0.085 and 0.303 o/o of hydrochloric acid ; these numbers being rather lower than those of Bidder and Schmidt.While enquiring into the acidity of gastric juice I observed that the degree of this re-action varied according to the period after the ingestion of food at which the fluid mas collected. The first quantity re- moved from the stomach was the most abundant but the least acid; gradually less and less of the secretion could be obtained but it became morc and more acid; while the last quantities 410 MARCET ON THE CHEMISTRY OF DIGESTION. of the gastric juice which were extracted exhibited the maximum degree of acidity.The following is a table showing the quan-tities of gastric juice extracted from a dog bearing a gastric fistula at different periods after the animal was fed and also the degree of acidity of the fluid expressed as potash necessary to neutralize 100 CC. of the secretioii. In four experiments the acidity invariably increased so much so that the degree of acidity was considerably greater towards the close of each experiment than it was at the beginning. Acidity of Gastric Juice. The time is counted just after the dog took his meal consisting of boiled wind-pipe. The acidity is expressed in grammes of potash necessary to neutralize 100 CC. of gastric juice. The experi- ments were made in middle of March 1860. No. I. Time after food taken.Quantity. Acidity. 30 minutes . . .. 201;. .... 0.065 40" later .... loz. .... 0.113 No. 11. 30 minutes .... lost. .... 30" later .. . . 20z. 2dr. .... 0.130 10" later .... 7dr. .... 0.156 10" later .... 6dr. .... 0.169 10" laier .... 5dr. .... 0.195 No. 111. 30 minutes ..I. 7dr. .. .. 0-208 30" later ...- loz. 6dr. .... 0'227 30" later .... loz. .... 0.273 30" later .... 3dr. .... 0.377 30m later ... loz. 5dr; .... 0.390 No. IV. 39 minutes . . .. 20z. 6dr. .... 0*180 10"later ,... loz. 3dr. .... 0.190 IF later .. .. 2oz. +dr. .... 0.235 15" later .... loz. 4dr. .... 0250 8" later .... 5dr. .... not determined. MABCET ON THE CHEMIBTRY OF DIGESTION. 411 This gradual increase of the acidity of gastric juice must be due partly to the first quantities which are secreted being diluted and neutralized by the slightly alkaline mucus contained in the fasting stomach; but more especially I believe because the fluid secreted towards the end of digestion is really more acid than that secreted at the beginning.This last hypothesis appears probable if it be remembered that the mucus of the stomach during the period of fasting is but slightly alkaline and exists therein but in small quantity. Whatever be the cause of the fact the gradually increasing acidity of gastric juice after food has been taken appears established and must serve some important purpose in connection with the process of digestion one of these objects being obviously to add to the power of the stomach of digesting those pieces of food which have not been properly masticated.The outside of each morsel of animal food which has beenmasticated will not require for its digestion the action of strong gastric juice; but the inside of the morsel especially in the case of animals which is not so well triturated with the teeth will require for its digestion the action of a more powerful or more acid gastric juice. If we consider the average acidity of gastric juice to be due to the presence of 0.253%of hydrochloric acid; and if it be admitted with Bidder and Schmidt that an adult man weighing about ten stone secretes in twenty-four hours about 6400 grammesof gastric juice then no less than about sixteen grammew (247 gms.) of fiee hydrochloric acid will be extracted from a human adult’s blood and returned into it in twenty-four hours.This acid must result from the decompodtion of chloride of sodium as was suggested by Prout* in 1834; but he adds “What becomes of the soda from which the muriatic acid has been disunited 3 ” He proceeds to state as his belief that the largest part of this soda is probably directed to the liver and passes off in the bile. We are now aware that such is not the case and Dr. Bence Jones by his researches on the acidity of the urine during the period of diges-tion and fasting has solved this interesting questi0n.t Blood is always alkaline; it must be so for the maintenance of health.$ There is however iv the blood a constant tendency to the farma- Chemietrg dc.of Digestion 1834 p. 600. 1. Phil. Tram 1849. $ Dr. Pavy has obaerved that after phosphoric acid has been injected hto the circulation the urinary secretion contain6 sugar. 412 MARCE'I' ON THE CHEJZISTRY OF DIGESTION. tion of acid.; but before the blood can turn acid the excess of this substance is elirniiiated by the secretions ; consequently acids are constantly being secreted from the blood aouietimes in the 'perspiration sometimes iil the urine sometimes by the stomach. When the secretion of acid in the urine is active that of the stomach is quiescent and vice versci; during the secretion of gastric juice the acidity of the urine is greatly diminished. At the time when digestion is at its height the acidity of the urine is at its minimum.These are the interesting results of Dr. Eence Jones' inquiries. We may therefore surmise that during diges-tion the chloride of sodium of the blood yields hydrochloric acid to the gastric juice while the soda is immecliately taken up by the acid which during fasting mould have been excreted with the urine but which remains in the circulation while digestion is going on. If chloride of sodium be the source of the principal constituent of the gastric juice-hydrochloric acid-this salt must be one of the most important immediate principles of the blood ; and we can un- derstand why when animals are for a time comparatively deprived of chloride of sodium in their food they eliminate none of this salt in their excrementitious secretions ;and consequently in such cases the same hydrochloric acid serves over and over again for the gastric secretion while all the other constituents of the body are undergoing the normal process of waste.This is one of those admirable provisions of nature which have fitted animal life to be preserved under so many different circumstances. The main object of the gastric digestion is the transformation of albuminous food into a substance which Lehmann has called peptone and the conversion of neutral fate into fatty acids Albumin fibrin casein gelatin and chondrin are modified in the stomach and assume new characters obviously in great measure with a view to their more ready absorption into the blood. Under the influence of the gastric juice albuminous or protein-corn pounds lose their coagulability by heat and mineral acids and likewise their property of forming insoluble combinations with most me-tallic salts.L e h m ann has been unable to discover any difference between the quantities of nitrogen carbon oxygen and sulphur contained in the peptone and in the substance from which it was derived. As to cartilage and gelatigenous bodies they are con- verted in the stomach into substances which according to Leh- mann cxrespond perfectly in their physical and in most of their chemical properties to the peptones of the protein-bodies. We MABCET ON THE CH$WISTBY OF DIQESTIO# 413 gather from the observations of this chemist that in his opinion the various peptones derived from protein and gelatin compounds are sufficiently analogous to be considered as one and the same body.Peptones must be looked upon as modifications of albumin fibrin casein gelatin and chondrin approximating to albumin of blood ; indeed they are partly assimulated compounds. Although I have no reason whatever to disbelieve Lehmann’s views regarding the analogy existing between the chemical characters of peptones still they do not appear to agree altogether in their physical properties j and this point is one of much intereat. Some peptonea or perhaps only one kind of peptone acts on polarised light rotating the plane of polarisation to the left while- others appear to exhibit no such property. I observed in the spring of 1860 that gastric juice acts on polarised light; and for the following twelve months I diligently inquired into the various circumstances connected with this phenomenon.Shortly after my results had been communicated to this Society I found in Henle and Meissner’s “Bericht uber die Vortschritte der Anatomie und Physiologie,” for 1859 that Hoppe had already observed this same optical property of the gastric fluid; and I willingly give up to him the priority of the discovery ; at the same time it should be understood that H oppe merely detected the bare fact and only expressed an opinion on its cause based on one experiment. He believed this phenomenon to be due to a substance secreted in tbe gastric juice while I have shown that it is owing to a product of the digestion of animal food or a peptone.There are two different animal tissues which when aubmitteu to the action of gastric juice in or out of the body yield polaris- ing peptone-these are cartilage and the mucous tissue of boiled intestines which can be easily separated from the muscular tissue. I could obtain none or no appreciable quantity of thiB substance from pure coagulated albumin or coagulated casein when digested in gastric juice out of the body. My experiments on the-digestion of meat out of‘ the body have failed to give me any clear reaults although dogs fed exclusively on cooked beef-steaks for a week invariably yielded a gastric fluid which acted on polarised light. We can be sure that the constituent of gastric juice which thue rotates the plaue of polarbation of light is a peptone and not a mbutance secreted; for if after keeping a dog fasting for thirty 414 BtABCET ON TEE CHEMISTaY OP DIGESTION.how or longer and then washing out his stomach thoroughly with water the animal be made to swallow silicious pebbles the small quantity of gastric juice secreted haa no power of rotating the polari~ed ray. The result of this experiment is at variance with that obtained by Hoppe who after allowing an animal to fast excited the gastric secretion with a glass rod without however taking the precaution of washing the stomach and found that the fluid acted on pokised light. Afker exciting the secretion with fragments of bone I obtained a gastric fluid which exerted but a very slight influence on polwised light showing only seven divisions’to the left in Soleil’s saccharometer while when the wcre- tion was excited by cartilage the rotation was from thirty to forty divisions obviously fiom the digestion of the cartilage; and moreover gastric juice mixed with cartilage or with the internal tissue of boiled tripe and exposed in a water-bath to a tempera- ture equal to that of the body acquires after a short time a power of deviating the plane of polarisation which may be twice as great as that it possessed befQre the commencement of the artificial digestion.After many experiments as to the best method of extracting from the gastric fluid the peptone under consideration I succeeded in preparing it in a comparatively pure state and then found it to be quite similar in its chemical properties to Lehmann’s peptone.Four experiments were made with the dry sibstance in order to determine its rotatory power in Soleil’s wharometer. Solutions of the peptone in twenty-five cubic centimetres of water yielded for lo,or division of the instrument 0020 0023,0.027 0.029 grammes average 0.024 grm. There-fore when gastric juice is examined in the saccharometer for every degree of rotation to the left the fluid contains 0.024grm. of polarising peptone or a proportion closely approximating to that in twenty-five cubic centimetres. Besides its office of transforming meat and allied articles of food into soluble substances the fctomach is possessed of another power no less important for the purposes of nutrition.I have discovered that it has the property of converting neutral fats containing stearin margarin and butgrin into their correspond- ing fatty acids; this fact simple as it appears is the key to the explanation of the digestion of fats. The fats of food are constantly neutisl they are not acidified by the process of cooking MARCET ON THE CHEMlSTRY OF DIGESTION. 415 although heated even for a length of time in contact with the acid juice of flesh and as fatty acids are found in the stomach it must be owing to a phenomenon of gastric digestion. if a dog bearing a gastric fistula be made to eat butter the fluid ex-tracted through the fistula a quarter of an hour or twenty minutes later or even less will smell strongly of butyric acid.The fat of beef or mutton after having remained for a certain time in the stomach yields to alcohol although not to water an acid reaction. When the food taken contains but little fat the whole of it perhaps is acidified during the gastric digestion ;in those cases where much fat is ingested I believe a part of it escapes from the stomach without having undergone any change. With respect to the olein of food I had concluded in a paper I communicated to the Royal Society in 1858 that this substance is not acidified in the stomach but I do not wish to be too positive'regarding this statement. The importance of the transformation of neutral fats into fatty acids in the stomach will be readily understood if we take into consideration the action of bile upon these substances the cha- racteristic physiological property of that secretion being its power of converting fatty acids into an emulsion while with regard to neutral fats it exhibits no such influewe consequently fats undergo in the stomach a certain transformation by which means the bile becomes capable of acting upon them and transforming them into an emulsion.I must now beg to make a few observations on the pheno- menon of fatty emulsions. When neutral fats or fatty acids in a fused condition are agitated with water no emulsion is formed but large globules are seen to pervade the fluid; on standing they immediately run into each other and rise to the surface the aqueous fluid remaining perfectly clear. When fused neutral fats are agitated with a solution of neutral tribasic phosphate of soda I have observed the same phenomenon to take place as with pure water but when fused fatty acids are treated with a solution of phosphate of soda an emulsion is formed or in other words the globules of fat lose the property of running into each other ; they remain separate the fluid assuming a milky appearance :consequently phosphate of soda does not act equally on neutral and on fatty acids.This subject appearing to me of great interest I have given it much attention 416 MABCET ON THE CHEMISTRY OF DIQEIJTION. and I have found that the emulsion produced by acting on fatty acids with phosphate of soda is invariably accompanied by the formation of R certain qaantity of soap; and a fact worthy of note is that the formation of soap persists although from the neutral phos- phate becoming transformed into an acid phosphate the emulsion is suspended in an acid fluid.Emulsions of fat are also produced when bile and fused fatty acids are agitated together or when pancreatic juice is shaken with both neutral or acid fats. This state of emulsion or of minute division of fats is indispensable for their absorption in the blood; an inquiry into the real nature of an emulsion would be therefore an object of much importance. Is it not something more than a mere mechanical division of fats into very small globules? I believe there are strong grounds for the as-sumption that there can be no emulsion without a chemical action which may be conceived to take place in the following way:-When hed fatty acids are shaken in a test-tube with phosphate of soda or bile the fat is instantly divided by a me-chanical process into very minute globules just aa would happen if the fat was agitated with water; but at that moment each of theae very small fatty particles becomes surrounded with a fayer of aoap from the surface of the globule being saponified by the phosphate of soda or bile.From this circumstance the globules of fat lose their property of running into each other and acquire a slight increase of specific gravity which however is not sufficient to prevent them from rising slowly in the mother- liquor and finally occupying the upper part of the liquid. Thus it is that the fluid is milky and that the emulsion takes a much longer time to rise to the surface than pure oil would.The chemical analysis of the emulsion bears out this view for I have found it to consist invariably of free fatty acid and soap. This theory may have been already propbsed without my know-ledge ;its adoption mill assist in explaining the absorption of fats EOr in this case when in the form of an emulsion they can no longer be in direct contact with the intestines a layer of soap intervening between the fat and the membrane. Soaps may be conceived to pase through a membrane whilst fat is known to be inmpable of so doing consequently we may imagine fats to be absorbed under the form of complex globules the inside of which is free fat and the outside soap.MARCET 0s THE CHEMISTRY OF DICEYTIOK. 417 Lct 11s now retnrri to thc action of bile iipon fats. After I had observed the property of phosphate of soda of emulsiorhlg fatty acid and not neutral fats it struck mc that bile might bc ~OS-sessed of a similar power diich I found to be tlic casc; and after giving this important subject all thc attciition it deserved the results of my cnqiiirics were communicated to the ltoyal Society in 1858. Shortly afterwards I mas informed that bile had already been observed by Lenz of Dorpat to possess the ahove- mentioned property ; and by rcferring to his valuable Disserta- tion “On the Digestion of Fats,” I found that he was th first who discovered so far back as 1850 that bile emulsioned fatty acids but not neutral fats; lie also noticcd that the emulsion was attended with the formation of soap mid I readily avail myself of this opportunity of acknonledgirig thc fact.I cannot find that Lenz conducted his experiments with other fats than oil. I employed the solid fats of meat which are those usually takcn into the stomach ; my attention was especially directed to the quantitative analysis of‘ tlic emnlsioii in order to determine the proportions of soap aid fatty acids it contained ; and finally I discowred this rcniarkablc anit intercstiug fact that if the mother-liquor in which thc emulsion is suspeiiclcd be filtered from the emulsioned fat it is capablc notwithstanding its strongly acid rcaction of foriniug morc soap and emulsioning more fatty acid although before filtration the sapoiiification had been entirely arrested; tlic filtrate from this second operation is likewise capable of efl’ecting a frirther saponification and emulsion hut the action is less and lcss powerful ; in one series of experi- ments the proportions of fatty acids saponified were 20.5 g,, 12.7% and 3.8 ”/o of thosc experimented on.The importance of the change wliicli ncutral fats undergo in the stomach mill now be readily understood ;for it is indispensable to their subsequent emulsion in the intestines by the bile under which form they arc absorbed. I do not wish however to attri-bute to bile exclusively the powcr of digesting fats for I fully believe that a portion of the fats takeii into thc stomach is not acidified and consequently mu& escapc the action of the bile; in this case the pancreatic juice eft’ects the required emulsion.It is remarkable that in both cases the fats are absorbed in great measure under the form of emulsioned fatty acids for it is now generally admitted that the pancreatic juice has the power of acidifying neutral fats as was discovered by Prof. I3ern ar d. 418 MABCET ON THE CHEMILSTBY OF DXGEBTION. This absorption of fatty acids explains a fact I observed with Mr. Verdeil while at work in Messrs. Wurta and Verdeil’s laboratory at Paris in 1851-namely that blood contains free fatty acids. The alimentary canal is so perfectly adapted to the functions of digestion that notwithstanding the great variety of food taken and the amount of nourishment ingested which is frequently much greater than that strictly required for the maintenance of the body only a very small proportion of food passes off in the evacuations in the healthy state; they may be said to contain no element of food soluble in water for they merely yield to water a stnall quantity of an albuminous substance possessed of the cha- racters of the albumin of the pancreatic juice which in all pro- bability it is.Under the microscope we find in the alvine dejections a few fragments of muscular tissue from the meat taken and the hairs of wheat ingested with bread; a few cells and fibres are all that remains of vegetable food. None of the fats of food are found therein in the free state but the evacua- tions contain sinall quantities of phosphate of soda soda soaps and a larger proportion of earthy phosphates and earthy soaps.The principal object of the alvine evacuation is obviously to rid the body of certain parts of the intestinal secretions which after having served their purpose in effecting the digestion of food are not fit to return into the blood. It is wry difficult to trace tlie connection of these excreted substances with the various intestinal secretions ; in this respect we must at present rest satisfied with probabilities. Among tliesc various substances there is one of great interest I haw called exwetiir [C,,€I,,O,S.] This substance which lias been fully described elsewhere,* crystal- lises from its alcoholic or ethereal solution exhibiting beautiful silky crystals which are acicular four-sided prisms.In its pro-perties it closely resembles chotestwin being soluble in hot alcohol and ether sparingly soluble in cold alcohol insoluble in water and not saponifiable; like cholesterin it dissolves in small quan- tity in the bile. It has also some physiological connection with chlolesterin as I have found the excreta of very young children to contain no excretin but chlolesterin whilst it is the reverse in the case of young people and adults. On this account I believe excretin to he a constituent of the bile. * Phil. Trans. 1854 ii 265.

ISSN:0368-1769    

DOI:10.1039/JS8621500407

出版商:RSC    

年代:1862

数据来源: RSC

摘要:

SCHORLEMNER ON TnE HYDBIDES ETC. L*-On the Hydridea of the Alcohol-radiclea exbting in the Produck of the Destructive Distillation of Cannel Coal. BY c. SCHORLEYMER Assistant in tho Laboratory oP Owem College Msnchester. THElight oils produced in the destructive distillation of coal have lately found so extended an application in the arts that the yield of these oils in the process of gas-making has proved quite insufficient to meet the trade demand. Considerable quantities of coal arc therefore now distilled with the sole object of obtaining liquid products. The yield of volatile liquid depends as is well known (l),upon the circum- stance that the distillation is conducted at as low a temperature as possible and (2) that the substances when once formed are not decomposed by cxposurc to a red heat.Blr. John Harrow of the Dalton Chemical Works Gorton near Manchester has been kind enough to place a sufficient quantity of the light oils obtained by the distillation of coal at my disposal to enable me to undertake a thorough examination of their chemical composition. They are obtained hy Mr. Barrow on the large scale by distilling Wigan Caniiel in retorts the lower surfaces of which are heated whilst the upper parts are kept as cool as possible. The crude oil possesses the peculiar smell of the compound aminonias and when these are removed by treating the liquid with dilute sulphuric acid the oil assumes the peculiar garlic-like smell of thc higher olefines. On submitting the oil to repeated fractional distillation a small quantity of liquid is obtained boiling below 20" C.a considerable quantity distils between 3s3--45O C. much less from 43"-65" whilst above 65' about equal portions distil for every 5' of increase of temperature. It was however founcl impossible to obtain a product of constant boiling point by repeated fractional distillations. When concentrated nitric acid is brought in contact with the 420 WHORLEMMER ON TEE FIYDBIDES OF oil so violent an oxidation occurs that spontaneous ignition of the more volatile portions of the oil sometimes takes place. When the action is ,moderated by cooling rr large portion of the oil remains unncted upon whilst considerable quantities of nitro-mapounds are formed. I coiifine myself in the present communication to the con-sideration of the liquide which remain unacted upon by nitric acid and me contained in the crude oil boiling below 120"C.The separation of these oils by means of nitric acid is a tedious and disagreeable operation. It may however be easily effected by previously shaking up the crude oil with an equal volume of ordinary sulphuric acid. The mixture becomes heated assumes a dark dour and gives off a smell resembling that of peppermint and after some time sulphurous acid is evolved. The liquids were allowed to remain in contact for several days and were frequently shaken; the oil was then poured off washed with water and distilled a large quantity of tarry matter being left behind in the retort.The distillate consisted mainly of henzol aid toluol together with the liquids unzlcted upon by acids. For the purpose of obtaining the latter liquids in the pure state I have employed the method described by Greville Williams in his researches on the hydrocarbons from Boghcad coal.* This method conaists in repeatedly shaking the oil with concentrated nitric acid until on addition of water to the acid liquid no fiirthcr separation of nitro-compounds occurs The liquid unacted upon is then washed with water dried owr potash and repeatedly rectified over sodium. By fractional distillation of this liquid the following four bodies were obtaiiieil-C5H12.... boiling point.. .... 39-40" C. ,9 €61314 .,.. ...... 68-'70", 9, G,HI6 .... ......98-99" , 6,H, .... > .,. . . 119-120" , It mill be shown that these liquids are the hydrides of the alcohol- radicles inasmuch as they have been transformed by the action of chlorine into their corresponding chlorides. * Fhil Transact. 1857. THE ALCOHOL-RADICLES ETC. 421 (1) fIydride of Arnyl G5HI2. Analpis 0*1870 substance gave 0,5715 carbonic acid and 0*2810water. Calculated. Found. . -~ G5 60 83.33 83-3 H, l2 16-67 16.7 c 72 1M).OO 100.0 Determination of Vapour-den~ty. (a) Substance taken .......... 0 alOIO*p. Temperature of ah ........ 16O.O C. Temperature of vapour.. .... 55O.O C. Vollime of vapour.. ........ 54O.8 cbc. Height of barometer.. ...... 752".0 mm. Difference of level ......... 235O.5 mm.The density calculated from these numbers is 2.523. (b) Temperature of vapour. .... 66O.O C. Volume of vapour.. ........ 56'4 cbc. Difference of level.. ........ 230"*0mm. Hence the vapour-density = 2.519. (c) Temperature of vapour.. .... 91O.O C. Volume of vapour.. ........ 59'5 cbc. Difference of level.. ........ 22OO.O mm. These numbers give the density of 2-497 closely corresponding to the theoretical density 2*493of hydride of amyl. Hydride of amyl is thin mobile liquid boiling between 39 and U"C. and possessing a pleasant smell resembling that of chloro form. Sp. gr. = 0636 at 17" C. It burns with a bright luminous non-fuliginous flame. These properties with the ex-ception of the boiling point correspond with those of the hydride of amyl as described by Frankland.Although a small portion of the purified oil distils over below 30" C. I SCHORLEMMER ON THE HYDRIDES OF did not succeed after repeiited fractimsl distillations in obtain-ing a liquid lisviiig a constant boiling of 30" C. as found by Frankland by far the greatcst part of the liquid distilling between 39-40' C. Greville TVilli ams bas lately shown the presence of hydride of aniyl in the oils obtained hy the destructive distillation of Boghead coal.* (2) Hydride of Hexyl (Caproylj :G6H1,. Analysis 0.1460 sulistance gave 0.4490 carbonic acid and 0.2135 M ater. Calculated. Found. A T / -% 7? 83.72 83.8 q4 1-4 16*28 16.3 86 100. 0 100.1 Determination of Vupoecr-density. Balloon with air ................23'0449 grnm Temperature of air .............. 15O.5 C. Balloon with vapour.. ............ 23'.720 grrns. Temperature on sealing .......... 110"*0C. Capatity of balloon ............... 178"*0 cbc. Hence the vapour-density = 2-98;the theoretical-density of hydride of hexyl is 2.98. Hydride of hexyl is a thin mobile liquid of a faint but pleasant smell burning with a luminous slightly smoky flame. Boiling point 68-70' C. Sp.gr. at 15'*5 = 0.678. Tbere can be little doubt that the body p0"sSeesing the ssme composition and boiling point which Greville Williama found in the oils from Roghead coal described in his first paper as pFOps1 is really hydride of hexyl. Caboura and Pelonoe have lately shown that it is contained in large quantities in the American rock oil.? * Journ.Chem. Soc. xv. 130. .t Phil. T~Iu.,1867. THE ALCOIIOL-BADICLES,ETC. 423 3. Hydride of Heptyl (Oenanthyl) G,H16* Analysis :-0-1765 substance gave 0.5440 carbonic acid and 0.2570 water. Calculated. Found. c7 HI6 89.0 16.0 - 84.0 16.1 - lOo*O lOo*l* Determination of Vapour-density. Balloon with air.. .............. 24'*368 grms Temperature of air.. ............ 18"*0C. Balloon with vapour ............ 24°s671grms Temperature on sealing.. ........ 150°*0C. Capacity of balloon ............ 17VQ cbc. Residual air .................. OO.3 cbc. These nuwbers give the vapour-density. ....... = 3-49 The theoretical density of hydrirle of heptyl is = 3-46 Uydride of heptyl is a liquid closely resembling hgdride of hexyl; it possesses a similar smell and burns likewise with a slightly smoky flame.Boiling point 98-99' C. Specific gravity at 17.5" = 0.709. When chlorine is passed into hydride of heptyl the liquid becomes warm and ilydrocldoric acid is given off. The substitu- tion-products formed are partially decomposed by nistillation ; hydrochloric acid is evolved and carbon separates out and the distillates assume green blue or purple colours which disappear after etanding for Borne time. A large portion however of the chlorinated liquid distils without decomposition ; and from this portion when the treatment with chlorine has not been carried too far a considerable quantity is obtained by fractional distillation boiling between 150-152' C (not corrected).This body pos-sesses the composition and properties of chloride of heptyl C,H15Cl. Analysis The combustion was effected with oxide of copper the front part of the tube containing copper-turnings. * Compt. rend. liv. 1241. SCHORLEMMER ON THE HYDRIDES OF 0.2522 substance gave 0.5765 carbonic acid and 0.2580 water. 0.20132 substance gave 0*2120 chloride of silver and 0.0036 metallic silver Calculated Found. 7-c7 84 62.45 62.3 H, 15 11-15 11.4 c1 35.5 26.40 26.4 134.5 100. 0 100*1 Cliltwide of Iieptyl is a colourless liquid of a pleasant smell burning with a smoky green-bordered flame and possessing the specific gravity of 0.891 at 19" C. When it is boiled with an alcoholic solution of acetate of potassium chloride of potassium separates out but the decompo- sition goes on very slowly.IVhen however the mixture is heated in sealed tubes to about 120-130° C. the chloride is completely decomposed in a few hours and the liquid consists of an alcoholic solution of acetate of heptyl which separates out on the addition of water as a light oily liquid having a strong and pleasant smell of pears. Treated mith an aqueous solution of potash this ether is easily decomposed and heptylic alcohol is formed possessing a peculiar ammatic smell resembling somewhat that of octylic alcohol as prepared from castor oil. I am at present engaged upon the investigation of the heptyl compounds. Besides the chloride of heptyl some chlorine-compounds boil-ing at higher temperatures and distilling without decomposition were formed but the quantity was only small and I did not succeed in obtaining a product of constant boiling point.Heated with sodium these chlorine-compounds are easily decomposed and a liquid free from chlorine is obtained which boils between 95-10O0 C. and possesses the peculiar smell of heptylene G7H,* Analysis 01618 substance gave 0.5080 carbonic acid and 0.2125 water Calculated. Found. r A \ G 84 85.71 85*6 H, 14- 14.29 14.6- 98 100*00 100.2 THE ALCOHOL-RADICLES ETC. 425 The quantity obtained was too small for determining the vapour- density (4) Hydride of Octyl (Cupryo c8H18' Analysis 0.2095 substance gave 0.6465 carbonic acid and 0.3040water.Calculated. Found. 84.1 16.1 -100.2 Deterinination of Vapour-density. Balloon with air ................ 7.098 grms. Temperature of air .............. 15.5" C. Balloon with vapour.. ............ 7-33 grms. Temperature on sealing .......... 170-0"C. Capacity of balloon .............. 119.5 cbc. The vapour-density calculated from those numbers = 3.98 The theoretical density of Hydride of Octyl is,. . = 3.95 Hydride of octyl in its physical properties closely resembles the hydrides of hexyl and hptyl. It boils at 119-lZOo and has a sp.ec. grav. of 0719 at 17O.5. In the above-mentioned paper on the hydrmrbone from the oil obtained by the destructive distillation of Boghead d Greville Williams has described as butyl 8 body of the above composition and boiling point which is doubtless hydride of octyl.The action of chlorine on hydride of octyl iS similar to the action on hydride of heptyl; a large portion of the products formed are decomposed when distilled; whilst the portion which volatilizes without decomposition yielas by fractional distillation a considerable quantity of a liquid boiling between 170-172" C. (not,corrected) which possesses the composition and properties of chloride of octyl G8H1,Cl. Analysis I. 0*1800 substance gave 0.4250 carbonic acid and 0.1895 water. 11. 01697 substance gave 1635 chloride of silver md 0.0015 metallic silver. SCHORLEMMZER ON THE 'EYDRIDES ETC. Analysis 111. 0.2342 substance gave 0.2280chloride of silver and 0-0012metallic silver.Calculated. Found. 7'-A I. n. 111. C 96 6465 64.4 -HI 17 11.45 11.7 -I C1 35-5 23.90 23.9 24.2 1443.5 100-0 Chloride of octyl is a colourless liquid possessing a faint but pleasant smell of oranges apd burning with 8 smoky green- bordered flame. Spec. grav. = 0*892,*at 18' C. Heated with an alcoholic solution of acetate of potassium it is decomposed in the same manner as chloride of heptpl. The volatile chlorine-compounds which are formed together with chloride of octyl were present in small quantity only and I was unable to obtain a product of constant boilingpoint. Heated with sodium they are easily decomposed and I observed the for- mation of the blue body described by B0uis.j-By repeated treatment with sodium at a higher temperature a liquid having a smell like that of heptylene was obtained boiling between 115-125" C.By fractional distillation the greatest portion was obtained between 115-1 17' C. Bouis gives the boiling point of octylene at 125' C. The analysis of the liquid boiling at 115-117" C. gave the following results :-Substance taken.. .. . .... . 0.1394 Carbonic acid obtained. ... 0.4375 Water obtained,. .. ...,. 0.1845 Calculated. Found; G8 96 85.71 H16 l6 1429 I _-__ 112 100*00 * It appears from a number of determinaliom that the spec. grav. of 87H15Cl and C,H,;CI are very nearly the same. I. Compt. rend xxxviii. 935. GRARAM ON CAPILLARY LIQUID TRANSPIRATIOK ETC.427 Determination of Vapour-density. Balloon with air ................ 8"Q015 grms. Temperature of air .............. 18O.5 C. Balloon with vapour.. ............ 8"*1080grms. Temperature on sealing .......... 177" c. Capacity of balloon.. ............ 51O.7 cbc. The density calculated from these numbers is ......... 4-17' whilst the theoretical density of octylene is .... 3.88. I have convinced myself that the oils from Camel coal having a higher boiling point than those I have as yet examined likewise contain substances unalterable by the strongest acids. There ap- pears therefore to be little doubt that "the whole peries of homo-logous hydrides are contained in the products of the distillation of coal at low temperatures; and I would venture the suggestion that the so-called paraffins which are likewise not acted upon by etrong acids may prove to be the higher members of the samc series.In conclusion I beg to express my best thanks to Professor Roscoe for the valuable advice which he has given me in carrying out the above investigation.

ISSN:0368-1769    

DOI:10.1039/JS8621500419

出版商:RSC    

年代:1862

数据来源: RSC