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THE QUARTERLY JOURNAL OF THE CHEMICAL S,OCIETY XXV.-Contributions to the History of the Phosphorus-Bases. BY AUGUSTUS HOFMANN, WILLIAM F.R.S. [Abstracted from a series of papers read before the Royal Society June 21 ISSO.] FIRST MXMOIR. IN a paper* published a few years ago by M. Cahours and myself the remarkable phosphorus-compounds whose existence was first pointed out by the experiments of M. Paul Thhard were subjected to a more complete examination than they had previously received. The discovery of a better mode of preparation enabled us to gain a clearer view of the nature of this group of substances and to throw additional light on their relations to the nitrogen-bases; hut owing to the overwhelming number of reactions which presented themselves we were unable to submit the behaviour of the phosphorus-bases with other groups of bodies to a detailed examination.In contimation of former experiments I have lately been much engaged in the investigation of the yolyatomic ammonias the study of which was naturally suggested by the beautiful researches * Philosophical Transactions vol. cxlvii p. 576. Chem. SOC.Qu. vol. xi p. 66. VOL. XIII. U which have been published on the polyatoinic alcohols. In the course of these experiments I frequently had occasion to return to the phosph3rus-bases the employment of triethylphosphine in particular having in many instances led to results which would not easily have been obtained in any other way. The possibility of preparing this body in a state of perfect purity and in considerable quantity by a aeries of processes which if not quite simple are at least definite and certain its position in the system of‘ organic compounds its conveniently situated boiling-point the energy and precision of its reactions and lastly the simplicity which charac- terizes these reactions in consequence of the absence of unreplacecl hydrogen in triethylphosphine,-whereby the formation of a large number of compounds of subordinate theoretical interest is excluded,-all these conditions tend strongly to invite us to the study of a body in whose chemical relations the leading qiiestions of the day are not unfrequently mirrored with surprising distinct- ness.It was originally my intention to put together-in one frame as it were-the various facts which I have collected relating to the phosphorus-bases; but the material lies scattered in so many directions that I deem it more advisable to publish these observa- tions in a number of shorter memoirs which from the nature of the subject must be more or less fragmentary.Preparation of TriethyIphos~hine.-The whole of the material used in my experiments was prepared by the process formerly described in detail by Cahours and myself. The only alteration which has been found advisable relates to the separation of the triethylphosphine From the chloride-of-zinc-compound which is produced by the action of trichloride of phosphorus on zinc-ethyl. It w3s formerly our practice to throw solid hydrate of potassium into the viwid mass of this salt and then to dissolve the potassa by gradually dropping water into the retart the heat resulting from the reaction being sufficient to carry over the base nearly anhydrous.It is better however to mix the double salt at once with water and then decompose it in a retort filled with hydrogen by allowing strong potassa-solution slowly to flow into it. On subsequently distilling the rnixtnre on a sand bath in a continuous but very slow stream of hydrogen the triethylphosphine passes over with the aqueous vapour and floats on the top of the con- IIiSTOIiY OF THE PHOSPEKORUS-BSSES* densed water in the receiver. By adopting this mode of pro-ceeding the reaction is more under the command of the bperator and as the phosphorus-base is not sensibly soluble in water the quantity of the product is not thereby diminished.By exact adherence to the prescribed conditions it is hy no meaus difficult to prepare considerable quantities of pure triethyl- phosphine ;nevertheless the amount obtained is always less than it should be in proportion to the weight of the materials used. This loss is mainly due to the formation of secondary products which cannot be wholly avoided even when the zinc-ethyl has been carefully prepared and to partial decomposition of the latter substance during distillation for it is scarcely possible to imagine a more elegant reaction than that which takes place between trichloride of phosphorus and ready-formed zinc-ethyl. Under these circumstances many attempts were naturally made to obtain the phosphorus-base in other ways; I have always however returned to our original process.Totally unsuccessful was the attempt to obtain triethylphosphine without previous preparation of zinc-ethy 1 by exposing a mixture of 1 equiv. of trichloride of phosphorus and 3 equivs. of iodide of ethyl with excess of zinc in sealed tubes to a temperature of 150"C. The bodies react under these circumstances; but as only traces of triethplphosphine are produced I have not thought it worth while to pursue this reaction further. A more favourable result was obtained by heating a mixture of zinc and phosphorus with anhydrous iodide of ethyl to between 150' and 160'. After several hours' digestion the tubes were found to be coated with white crystals and a considerable portion of the phosphorus had passed into the red modification.Powerful escape of gas always took place on opening the tubes and in several instances they were shattered even when their points were softened in the lnmp- flame to diminish the violence of the concussion. Besides zinc- ethyl tLe presence of which is indicated by the abundant evolu- tion of hydride of ethyl which is observed on treating the contents of the tube with water tlie chief products of this reaction are three phosphorus-compounds which are formed in proportions varying according to the temperature and the duration of the action. On extracting the brown residue in the tubes with warm water and evaporating the clear solution an oily snbutance separates v2 DR.HOFMANN’S CONTRIBUTIONS TO THE wlhh covers the bottom of the dish and on cooling solidifies into a mas3 of hard crystals. By repeatedly crystallizing this substance from boiling water and from alcohol large crystals are obtained which give off triethplphosphine when treated with potassa even in the cold; by analysis* they were found to consist of a compound of iodide of zinc with iodide of triethylphosphonium composed according to the formula A solution of iodide of triethylphosphoniurn mixed with iodide of zinc immediately gives a crystalline compound of exactly similar characters. The mother-liquor of the double salt yields when further evaporated another crystalline body which is more dificult to purify.After three or four crystallizations however well-developed crystals are obtained which do not yield triethylphos- phine when treated with potash either in the cold or with aid of heat. Analysis sliows that this crystalline substance is a cornpound of iodide of zinc and oxide of triethylphosphine c6Hl5P0,ZnI =(C,H,),PO ZtIL The third compound which remains in the mother-liquor after the two former have crystallized out and separates on further evaporation in beautiful needle-shxped crystals may be recognized without difficulty as iodide of tetrethrlphosphonium. The crystals are insoluble in cold potassa-solution and give off triethylphos-phine only Then heated with solid hydrate of potassium. This iodide likewise unites with iodide of zinc; and as this latter salt is always present in the mother-liquor in considerable quantity the double salt is generally obtained together with the simple iodide.* The combustion of the phosphorus-compounds is not very easily effected. The experiment succeeds best with a mixture of chromate of lead and oxide of copper. All the carbon-determinations quoted in the following pages have been made with this mixture unlcss another mode of proceeding is specially stated. A11 the sub-stances atialysed wer dried at looo except in a few cases when the mole of drying is also specially mentioned. The det~ilsof the analytical determinations are given in the original papers published in the Philosophical Transactions for 1860. .f.H=l; 0=16; S=82; C=12. HISTORY OF THE PHOSPHORUS-BASES The mode of formation of these compounds is represented hy the following equations :-4C2H51+P+3Zn = [(C2H5),HP]T Zn I+2Zn T+C,€€,. 4C2H,I + P + 3Zn = f(CzH5)4P]I ZnI + flZnT. The compound containing oxide of triethylphospfiine is evidently formed at the expense of the air in the tube :-(C,H5),P+0+Zn I = (C,H,),PO ZnI. The above zinc-iodide-compounds of triethyl- and te trethyl-phos- phonium possess interest only in so far as they may serve for the preparation of phosphorus-base. The mixture evaporated to dry- ness and distilled with hydrate of potassium in an atmosphere of hydrogen does indeed yield appreciable quantities of triethylphos-phine the action of iodide of ethyl upon a mixture of zinc and phosphorus may therefore be recommended when it is desired to prepare a sample of this remarkable compound without specially arranged apparatus but it is not adapted for the preparation of the phosphorus-base on the large scale.I have endeavoured to prepare by this process triarnyliwhosphine and triaZZy&hosphine but the results were not such as to encourage me to continue the experiments. Ca h ours has recently made similar experiments but with a difference in the mode of conducting them which cannot fail to influence the result. Instead of subjecting iodide of ethyl to the action of a mechanical mixture of zinc and phosphorus he has caused the compound Zn P to act upon iodide of ethyl at a high temperature. The reaction will doubtless proceed more regularly under these conditions ;but the advantage which may perhaps be gained by avoiding the preparation of the zinc-ethyl is corn-promised at least in part by the time and trouble expended in the somewhat complicated preparation of trizinco-phosphide.Oxide of TriethyliPhosphine.-The formation of the compound of this oxide with iodide of zinc to which I have alluded induced me to subject to a careful examination the beautifully crystallized body produced from the phosphorus-base by exposure to the air. In our former experiments Cahours and myself had often observed this substance but we did not succeed in obtaining it in 294 DR HOPMANN’S COKTRIBUT1C)NS TO THE a state of purity fit for analysis. ‘Nevertheless founding our conclusion on the composition of the corresponding sulphur- compound and having rcgard to the amlogics presented by the bodies of the arsenic- and antimony-series we regarded this body as the oxide of the phosphorus-base C6H,,P0 = (C,H,),PO.I have since confirmed this formula by analysis. The difficulties which in our former experiments opposed the preparation of this compound in the pure state arose entirely from the comparatively small quantity of material with which we had to work. Nothing is easier than to obtain this oxide in a state of purity provided the available quantity of material is sufficient for distillation. In the course of a number of preparations of triethyl-phosphine for the new experiments a considerable quantity of the oxide had accumulated in the residues left after distilling the zinc- chloride-compound with potassa.On subjecting these residues to distillation in a copper retort a considerable quantity of the oxide passed over with the aqueous vapours; and a further quantity was obtained as a tolerably anhydrous bnt strongly coloured liquid by dry distillation of the solid cake of salts which remained after all the water had passed over. The watery distillate with or without addition of hjdrochloric acid was evaporated on the water-bath as far as practicable and the concentrated solution was niixed with solid hydrate of potassium which immediately separated the oxide in the form of an oily layer floating on the surface of the potash. The united products were then left in contact with solid potash for twenty-four hours and again diatilled.The first portion of the distillate still contained traces of water a thin layer of triethylphosphine floating upon the surface. As soon as the distillate solidified the receiver was changed and the remaining portion (about nine-tenths) collected apart as the pure product. With reference to the properties of oxide of triethylphosphine I may add the following statements to the description formerly given*. This substance crystallizes in beautiful delicate needles which if an appreciable quantity of the fused compound be allowed to cool slowly frequently attain the length of several inches. I have been unable to obtain well-formed crystals ;as yet I have not * Philosophical Transactions 1857 p.586 ; Chem. 8oc. Qu. vol xi p. 66. XIISTOBY OF THE PHOSPHORUS-BASES found a solvent from which this substance can be crystallized. It is soluble in all proportions both in water and alcohol and separates from these solvents on evaporation in the liquid condition and solidifies only after every trace of water or alcohol is expelled. Addition of ether to the alcoholic solution precipitates this body likewise as a liquid. The melting poiut of oxide of triethylphos-phine is 44' ;the point of solidification at the same temperature. It boils at 240' C. (corrected). As no determination of the vapour-density of any member of the group of compounds to which the oxide of triethylphosphine beloegs has yet been made it appeared to me of some interest to perform this experiment with the oxide in question.As the quantity of material at my disposal was scarcely sufficient for the determination by Dumas' method and Gay-Lussttc's was in-applicable on account of the high boiling-point of the compound I adopted a modification of the latter consisting essentially in generating the vapour in the closed arm of a U-shaped tube filled with mercury and immersed in a copper vessel containing heated paraffin and calculating its volume from the weight of the mercury driven out of the other arm. As I intend to publish a full descrip-tion of this method which promises to be very useful in certain cases I slid1here content myself with stating that the results of my experiments prove the vapour-density of oxide of triethylphos-phine to be 66.30 referred to hydrogen as unity or 4.60 referred to atmospheric air.Assuming that the molecule of oxide of triethyl-phosphine corresponds to 2 vols. of vapour,* the calculated specitic 134 gravity of its vapour = - 67 when referred to hydrogen and 4-63 when referred to air. Hence we may conclude that in oxide of triethylphosphine the elements are condensed in the same manner as in the majority of tlioroughly investigated organic compounds. From the fmility with which triethglphosphine is converted into the oxide by exposure to the air even at ordinary temperatures and from the very high boiling-point of the resulting compound in consequence of which its vapour can exert but very slight tension at ordinary temperatures I am induced to think that the phosphorus-base may be used in many cases for the volumetric estimation of oxygen When a paper ball soaked in triethylphos-* H,O =2 vols.of vapour. 296 DR HOFMANN'S CONTRIBUTIONS TO THE phine is passed up into a portion of air confined over mercury the mercury immediately begins to rise and continues to do so for about two hours after which the volume becomes constant the diminution cwresponding very nearly to the proportion of oxygen in the air. To obtain very exact results however it would pro- bably be necessary in every case to remove the residual vapour of triethylphosphine by means of a ball saturated with sulphuric acid. Oxide of triethylphosphine exhibits in general but small ten- dency to unite with other bodies ;nevertheless it forms crystalline compounds with iodide and bromide of zinc.I have examined more particulaly the zinc-iodide-compound already mentioned. Oxide of Triethybhosphine and Iodide of Zinc.-On mixing the solutions of the two bodies the compound separates either as a crystalline precipitate or in oily drops which soon solidify with crystalline structure. It is easily purified by recrystallization from alcohol and contains- C,HJ? 0,Zn I = (C2HJ3P0,Zn I. It is remarkable that this compound is formed in presence of a large excess of hydriodic and even of hydrochloric acid The crystals melt at 99O they readily dissolve in warm water Fig. 1. and even more easily in alcohol.From the alcoholic solution well-formed crys- tals are frequently obtained. My friend Quintino Sella has ex-amined these crystals. * '" '' System monoclinic :-100 101 =:34' 25'; 101,001~48'48' ; 111 010 = 50" 16'. Forms observed :-OOF 100,010 001 110 011 111 (Fig. 1). Combinations observed :-110 001 (Fig 2). 110 001; 100 (Figs. 3 & 4). 110 001; 100 010 (Fig. 5). 001 100 110 111. 001 100 110 111; 011. 001 100 110 111; 011 010 (Fig. 6). * The details of the crystallographical determinations are given in the original papers published in the Philosophical Transactions for 1860. HISTORY OF THE PHOSPHOEUS-BASES. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. DO Hemitropic crystals with the axis of hemitropy [loo] with the face of hemitropy 001.The hemitropic crystals are sometimes Fig. 7. simple as in Fig. 7; sometimes compli- cated as in Fig. 8. It is then difficult to distinguish them from trimetric crys- fj$,) tals ; they become however intelligible 4,; ) by assuming that they result from four /Ih) (1001 hemitropic crystals grouped round [loo] as in Fig. 9. It is found sometimes that several crystals like those of Fig. 8 are associated by 001. Fig. 8. Fig. 9. It deserves to be noticed that the crystals (Figs. 2 3 4,5 and 7) were formed in the presence of hydrochloric acid and that in DR. HOFMANN'S CONTRIBUTIONS TO THZ the absence of this acid only crystals of Fig. 8 are obtained which without the study of the cleavage and the optical characters could not be distinguished from trimetric crystals.Cleavages 001 and 110 neat and easy. The cleavage 110 of the hemitropic crystals (Fig. 8) exhibits re-entering angles. Lustre vitreous on the fracture fatty on the faces. Hardness st>mewhat greater than that of gypsum. The crystals are optically positive; the line of symmetry [OlO] is their principal medium line. The internal angle of the optical axes differs but little from 78" and the plane which contains them is nearly perpendicular to the edge of the prism 110. The smallest index of refraction is approximately y= 1.58." Oxide of Triethylphosphine and Dichloride of Platinum-No precipitate is formed on mixing the aqueous solutions of the two compounds however concentrated ; but on adding the anhydrous oxide to a Concentrated solution of dichloride of platinum in absolute alcohol a crystalline platinum-compound is deposited after a few moments.This compound is exceedingly soluble in water easily soluble in alcohol insoluble in ether. On adding ether to the alcoholic solution the salt is precipitated although with difficulty in the crystalline state. The alcoholic solution when evaporatiiig spontaneously yields beautiful hexagonal plates frequently of rather large dimensions. On account of its extreme solubility it is not quite easy to obtain this salt in con- siderable quantity. Analysis has led to the somewhat complicated formula Fig. 10. 001 The platinum-salt has likewise been examined by Quiritino Sella.'c System monoclinic :- 100 101 = 27' 19'; 101 001 = 46" 23'; 010 111 t= 41" 4'. Forms obszrved :- 100 001 210 101 111 112 (Fig. 10.) HISTORY OF THE PHOSPHORUS-BASES* Combinations observed :-001 100 110. (Fig. 11). 001 110 i12 ioi. 001 110 ii2 iol loo ill (Fig. 12). Fig. 11. Fig. 12. Cleavages 701 and 110 neat and easy. Colour orange-red. The optical axes are situated in 010 i. e. in the plane of spn-metry. They are seen across the faces 001 and the cleavages iOl and they make an apparent angle of about 64O.” On mixing a concentrated solution of the oxide of triethylphos-phine with trichloride of gold a deep-yellow oil is separated which crystallizes with difficulty after considerable standing. This com- pound is exceedingly soluble in water and in alcohol.When the aqueous solution is heated the gold is reduced; the transformation which the oxide of triethylphosphine undergoes in this reaction has not been examined. Chloride of Tin forms likewise an oily compound with the oxide :I have not succeeded in crystallizing this compound. Chloride of Mercury is without any action on oxide of triethyl-phosphine. Oxychloride of Tr.iethy&hosphine.-On passing a current of dry hydrochloric acid through a layer of oxide of triethylphosphine which is fused in a U-shaped tube surrounded by boiling water brilliant crystals are soon formed. These crystals however rapidly disappear the compound formed in the commencement of the reaction uniting with an excess of hydrochloric acid.The 300 DR. HOFMANN'S CONTRIBUTIONS TO TELE viscous liquid which ultimately remains behind loses when heated the excess of hydrochloric acid leaving an exceedingly deliquescent crystalline mass very soluble in alcohol iiisoluble in ether. For analysis the new compound was washed with absolute ether and dried over sulphuric acid in vacuo either at the common temperature or at 40". Three chlorine-determinations in speci- mens of different preparations led to the formula which represents an oxychloride of triethyphosphine. The dichloride of triethylphosphine cannot be formed by the action of hydrochloric acid upon the oxide. The oxychloride exhibits with other compounds the deportment of the oxide. It furnishes with dichloride of platinum the same platinum-salt which is obtained with the oxide.In a similar manner it gives with iodide of zinc the iodide-of-zinc-compound of the oxide previously described. Only once-under conditions not sharply enough observed at the time and which I was afterwards unable to reproduce in repeated experiments-a compound of the oxychloride with iodide of zinc was formed. This substance readily soluble in water and alcohol crystallized from the latter solvent in beautiful colourless transparent octahedra which on analysis gave results leading to the formula C,,H,,P,0C1,Zn,T2 =(C,H,) ,PO,ZnI +(C,H,),PCl,,ZnI. Behaviour of Triefhybhosphine with Xu123hur-com~ounds.-The remarkable tendency of the phosphorus-base to unite with sulphur has already been mentioned in the previous memoir the com-bination of the two bodies is attended with evolution of heat the result being a beautifully crystalline substance corresponding to the oxide of triethylphosphine.This behaviour has induced me to study the action of several sulphur-compounds on the phosphorus-base. In the cases which I have examined the ultimate product is almost invariably the sulphide of triethylphosphine already mentioned as resulting from the direct combination of the phosphorus-base with sulphur ; but HISTORY OP THE PHOSPHORUS-BASES. the conditions under which this sulphide is produced vaty con-siderably; and in the majority of cases it occurs only as & secondary product of the decomposition of other more direct compounds some of which appeared to me sufficiently interesting to deserve more minute investigation.In the course of the experiments which I am going to describe I have prepared considerable quantities of the sulphide of triethyl-phosphine. This compound although remarkable for t'ae facility with which it crystallizes is not easily procured in well-formed crystals. It was only once or twice that I obtained crystals with good faces. They were examined by Quintino Sella who com-municates to me the following results :-'' System rhombohedric :-100 111= 54O 35'. Forms observed :-ioi 2ii 210 (Fig. 13). Combinations observed :-lOi 210 (Fig. 14). ioi 210; 211. Fig. 13. Fig. 14. At summer heat the crystals are very soft and flexible; they may be bent 180"without breaking.At lower temperatures they are harder and much less flexible. The crystals are optically positive. The index of refraction for the extraordinary ray e=1"65 and for the ordinary ray 0=1*59. Behaviour of Triefhy@hosphinewith SuBhuretted Hydrogen.- The phosphorus-base has no action on sukhuretted hydrogen. DR. ROFNA?JiT'S COSTRIBOTIOXS TO TEIE Whn & is brought in contact with hydrosulphuric acid over mercury the gas does not exhibit any alteration. No sulphide oE triethylphosphine is formed even in presence of air as might indeed have been expected. The attraction of the phosphorus- base for oxygen prevents the oxidation of the sulphuretted hydrogen; a solution of this gas in water when mixed with a few drops of triethylphosphine may be preserved in air-filled vessels much longer than without this addition.Behaviour of Triet~y~~~$~~~ine with Subhide of Nitrogen.-Siclphide of Nitrogen N S prepared as recommended by Fordos and Gelis viz. by the action of ammonia on chloride of sulphur dissolved in disulphide of carbon is decomposed by triethylphos- phine with evolution of light and heat. Gas is evolved and at the same time a yellowish liquid is produced which on cooling solidifies into a fibrous mass of crystals of tlie sulphide. Behaviour of Triethykhosphine with 2Mercaptan.-When these two bodies are mixed together in an atmosphere of carbonic acid ti0 alteration takes place even if they are left in contact for some time or if they are heated to 100" in sealed tubes for twenty-four hours.But if the mixture be poured into an air-filled flask crystals of sulphide of triethylphosphine make their appearance in a few hours. The crystals increase if the air has free access to the mixture; but if the flask be corked the crystallization is inter-rupted. On opening the flask the entry of the air uay be recognized by the light cloud which the phosphorus "base diffused through the atmosphere of the vessel forms with the oxygen. When a mixture containing excess of mercaptan was left for a few days in an open flask every trace of phosphorus-base had dis- appeared axid the re maining colourless liquid was filled with crystals of the sulphide. On mixing this liquid with water it separated into two layers the upper of which quickly solidified especially on exposure to the air to an imperfectly crystalline mass easily recognized as a mixture of sulphide of triethylphos- phine with excess of mercaptan.The impure crystals were exposed for a while to the air and then recrystallized from boiling water when on analysis they gave results agreeing with the formula C611,,PS =(C,H,),PS. HISTORY OF THE PHOSPEIORUS-BASES. The lower stratum of liqnid is aqueous alcohol containing sixd quantities of oxide of triethj lphosphine and mercaptan. To remove the latter the liquid was shaken up with recently precipi- tated mercuric oxide and distilled. The distillate rectified several times over lime yielded a clear liquid which burnt with a colour-less flame and exhibited all the characters of alcohol.The interpretation of this result appears at the first glance exceedingly simple ;the sulphide of triethylphosphine cannot be formed directly from the phosphorus-base but owes its origin to the oxide first produced by the action of air this oxide being decomposed by the mercaptan and yielding sulphide of triethyl-phosphine and alcohol Experiment shows however that this equation illustrates only the final result of the reaction. Oxide of triethylphosphine and mer- captan brought together under the most various conditions at ordinary temperatures and under pressure do not yield a trace of sulphide of triethylphosphine ;and we have to sixppose therefore that the rnercaptan interchanges its sulphur with the oxygen of the oxide of triethylphosphine only at the instant of formation of the latter or what comes to the same thing that the oxygen of the air in presence of a substance so greedy of sulphr as triethylphos-phine directly takes the place of the sulphur in the mercaptan.In connection with this suhject various attempts were made to replace the oxygen in oxide of triethylphosphine by sulphur. But neither by treatment with sulphide of ammonium nor by continued boiling with the higher sulphides of potassium could the oxide be converted into the corresponding sulphide whereas the conversion of the sulphide into the oxide takes place without any difficulty. This however is not more than rniglit have been expected from the behaviour of the oxide with hydrochloric acid mentioned in one of the preceding paragraph.The different degrees of stability which characterize the oxide and the sulphide of triethyl-phosphine may also Be strikingly seen in the behaviour of these compounds with sodium the sulphide being reduced with the greatest facility to free triethylp hosphine even below t'tle melting-point of the sodium whereas the oxide may be distilled DR. HOFMANN’S CONTRIBUTIONS TO THE from sodium without experiencing the slightest alteration.* Xbullition with ordinary concentrated nitric acid likewise converts the sulphide into the oxide the sulphur being at the same time transformed into sulphuric acid. The liquid filtered off from the precipitate obtained by barium-salts when evaporated to dryness and fused with nitrate of potassium yields no further trace of sulphur.with Disubhide Behaviour of ~ie~~~~ho$p~~ne of Carbon.-These two bodies when mixed in the anhydrous state act upon one another with considerable force amounting frequently to explosive violence and unite into a red crystalline mass. The compound is best prepared by mixing the solutions of its consti- tuents in alcohol or ether the new body then instantly separates in beautiful red crystalline laminae. Several times recrystallized from alcohol and dried over sulphuric acid the new body has furnished results leading to the formula The red crystals are not .the only product of the action of disul-phide of carbon on triethylphosphine.A second beautifully crystallized compound is deposited after some time from the mother-liquor. This substance is formed in extremely minute quantity :its nature is not yet established. The compound of triethylphosphine with disulphide of carbon is insolubte in water sparingly soluble in ether moderately soluble in disulphide of carbon and somewhat more soluble in alcohol especially when heated. The solution has no action on vegetable colours. From the boiling alcoholic solution it separates on cool-in red needles somewhat resembling the crystals of chromic acid which are formed by the action of strong sulphuric acid on a solu-tion of chromate of potassium. The ethereal solution left to evaporate in an open cylinder deposits finely developed deep-red crystals of considerable size.Quintino Sella has examined these crystals with the following results. * In the previous memoir it is Rtated that the phosphorus-base is reproduced from the oxide by the action of metallic sodium. Probably the oxide used in the former experiments contained a small quantity of free triethylphosphine and thus led to an erroneous statement. HISTORY OF THE PHOSPTrORUS-BASES. ‘‘ System monoclinic :-100 101=29O41&’;010 111=74°4’; 101,001=27” 7$’* Forms observed :-100 010 001 110 101 (Fig. 15.) Combinations observed :-100 110 001 TO1 (Fig. 16.) 100 110 001 iOl 010 (Fig. 17.) Fig. 16. Fig. 17 Cleavages :-010 100 neat and easy. The crystals are optically positive the medium-line coincides with the axis of symmetry [OlO].The interior angle of the optical axes is not very different from 70’. The plane of the optical axes is nearly parallel to the face 001. The axis of sym-metry or of smallest elasticity exhibits a violet-red colour which even in very thin layers is very intense. The axis nearly parallel to [loo] or the axis of greatest elasticity exhibits a similar but much lighter red tint. The normal shows in thin layers a straw- yellow in thicker layers an orange-yellow colour. In polarized light one of the most beautiful examples of dichroisrn is observed by looking across the faces 010 the colour passing in the case of thin layers from a pure yellow to a deep red. But even in ordinary light the dichroism is perceptible; for the light passes with a violet-red across the faces 100 and with an orange-red colour of far less intensity across the faces 010.Hardness less than that of gypsum.” The red crystals appear to possess the character of a weak base. They dissolve in strong hydrochloric acid forming a colourless liquid from which potassa or ammonia throws down the com- pound in its original state though somewhat lighter in colour on VOL. XIII. s DR. HOFMANN'S CONTRIBUTIONSTO THE account of its minute state of division. The acid solution forms with dichloride of platinum a light yellow amorphous salt in- soluble in alcohol and ether which changes colour and somewhat decomposes on drying. It darkens in colour even when dried in vacuo hydrochloric acid fumes being evolved.The analysis of a slightly decomposed salt gave results approximately agreeing with the formula (C2 H,) P CS, H C1 PtCI, The gold-salt is obtained like the platinum-salt and exhibits similar proper ties. It is not very easy to form a clear notion of the constitution of the red crystals. According to the formula the compound is the primary triethylphosphonium-salt of sulphocarbonic acid minus 1 equiv. of sulphuretted hydrogen and corresponds therefore to sul- phocarbamic acid the ammonium salt of which as is well known is produced by the action of ammonia on disulphide of carbon. There is however no analogy in the constitution of the two substances. The red crystals exhibit a remarkable tendency to pass into the sulphide of triethylphosphine.On mixing their alcoholic solution with oxide or nitrate of silver carbonic acid is evolved sulphide of silver and metallic silver are separated and the filtered solution when evaporated deposits crystals of the sulphide The disulphide-of-carbon-compound undergoes a similar change even under the influence of moisture. Crystals which had not been dried with sufficient care were changed after a few months when kept in corked tubes into a yellowish white semifluid mass of peculiar odour which by recrystallization from boiling water furnished a considerable quantity of pure sulphide of trietbylphos- phine. To establish this transformation by numbers the purified crystals were identified by analysis. It is obvious that the transformation of the red crystals into the sulphide involves the co-operation of the elements of water.Per-fectly dry crystals were preserved in sealed tubes for many months without the slightest alteration. The crystals fuse at 95" and volatilize at 100";in the absence of moisture they may be heated HISTORY OF THE PHOSPXORUS-BASES* under pressure to 150" without undergoing any decomposition. The phenomena are very different in the presence of water. When exposed for some days in sealed tubes with water to a temperature of lOO" the red crystals are gradually transformed into white needles which are easily recognized as sulphide of triethylphos- phine. The transformation is independent of atmospheric air for it takes place with equal facility in vessels with air or carbonic acid or inuacuo.The products which accompany the sulphide formed in this reaction vary according to the time during which the red crystals are digested with water. If the tubes be allowed to cool after one . or two days' digestion the liquid generally becomes filled with white needles which are however stiil intermixed with red prisms showing that the transformation is not yet complete. Scarcely any gas escapes when the tubes are opened but when gently heated the liquid yields abundance of disulphide of carbon. On the other hand when the tubes are heated until the transfor- mation of the red compound is accomplislied,-which generally takes place after three or four days' digestion,-a large volume of gas escapes on opening the tubes and they are occasionally shattered.The gas which is thus evolved consists of sulphuretted hydrogen and carbonic acid which are obviously secondary products of the reaction arising from thc protracted action of the water upon the disulphide of carbon wliich is separated in the first stage of the process. The liquid fro= which the crystals of sulphide have been deposited has a distinctly alkaline reaction which belongs neither to the sulphide nor to the red crystals from which the sulphide arises both these compounds being without action on vegetable colours. To seize the basic substance the liquid was evaporated on the water-bath till the sulphide had been as far as possible expelled and then precipitated with iodide of zinc which does not combine with the sulphide traces of this body which might have remained being in this manner eliminated.The iodide-of-zine- precipitate was semisolid and slowly became crystalline on treat-ment with alcohol ;it did not however exhibit a sufficiently definite appearance to warrant its analysis. The bases were therefore at once liberated again by digesting the precipitate with oxide of silver ;the powerfully alkaline liquid thus obtained gave on addi- tion of hydrochloric acid and dichloride of platinum a difficultly soluble platinum-salt crystallizing after the necessary purification x2 DR. HOFMANN'S CONTRIBUTIONS TO TRE from bdiiihg water in splendid octohedra which on analysis proved to be the methyl-triethy1phosphoniu~-compound.The solution filtered off from the octohedral salt gave on evapo- ration the extremely soluble six-sided tables of the platinum-salt of oxide of triethylphosphine which I have mentioned in the commencement of this paper. The products of the action of water upon the red crystals then are sulphide of triethylphosphine-the principal product-oxide of triethylphosphine hydrate of methyl-triethylphosphoniurn and disulphide of carbon which may be partly or entirely converted into sulphuretted hydrogen and carbonic acid. Four molecules of the disulphide-of- carbon-compound and two molecules of water contain the elements of two molecules of the sulpliide one mole- cule of the oxide one molecule of the hydrated phosphonium and three molecules of disulphide of carbon Whilst engaged with the experiments involved in the elucida- tion of this subject I observed occasionally small well-defined yellow crystals disseminated among the mixture of white and red needles which are deposited when the digestion-tubes are allowed to cool before the transformation is terminated.The yellow crystals appeared in greater quantity towards the close of the operation and were found to be a secondary product formed by the action of the sulphuretted hydrogen which is generated in the last stage of the process. I have since learnt to prepare the yellow crystals by a simpler and more definite method. This remarkable compound has become the starting-point of a new enquiry the result of which I reserve for a later communication.The formation of the red crystals by the union of triethylphos- phine and disulphide of carbon takes place so rapidly and with such facility that ever since the first time T observed this phenomenon I have used the disulphide of carbon as a reagent for the detection of the phosphorus-bases for trimethylphosphine exhibits a deportment perfectly similar to that of the ethyl-body. The minutest quantities of these bases may thus be readily and HTSTORP OF THE PHOSPHORUS-BASES. 309 safely recognized. The reaction is best observed by pouring the liquid to be examined upon a watch-glass and allowing thevapour of the disulphide of carbon to flow from an inclined bottle upon the liquid. The watch-glass immediately becomes coated with a beauti- fulnet-work of the red crystals.It requires scarcely to be men- tioned that the crystals are formed only when the phosphorus- bases are free. They appear however readily on adding to a mixture of their salts and disulphide of carbon a drop of potash which liberates the bases. On the other hand triethylphosphine may be employed with the greatest advantage as a test for disulphide of carbon. There is in fact no test for this substance which in delicacy could be compared with it By its aid the presence of the disulphide in the most volatile fractions of coal-tar-benzol is readily proved ; even the exceedingly small quantity of disulphide of carbon diffused in the most carefully purified coal-gas may as I have shown already in another place,* be recognized without any dimculty.In order to satisfy myself that disulphide of carbon may be employed with safety as a test for the phosphorus-bases it was necessary to examine the deportment of this compound with the arsines and stibines. Disulphide of carbon exhibits no reaction with triethylarsine and triethylstibine. I have left mixtures of these bases with the disulphide in contact for a considerable length oftime both at the common temperature and at looo without being able to observe the slightest alteration. I have also satisfied myself that disulphide cf carbon at all events in the common temperature is without action upon phosphoretted hydrogen. In examining somewhat minutely into the deportment of triethylphosphine with sulphur-compounds the organic sulphocya- nates could not be left nnnoticed.My attention was in the first place fixed by the sulphocyanate of phenyl which I had just dis-covered at the time I was engaged in the study of tliese reactions. Action of Sulphoeyanate of Phenyl upon ~r~eth~~~~o~p~~ne. The reaction between the two substanees in the anhydrous state is very * Quarterly Journal of the Chemical Society vol. xiii.. p. 87. DR. HOFYANN'S CONTRIBUTIONS TO THE violent and frequently causes the inflammation of the phosphorus- base. The mixture assumes a deep-yellov colour and on cooling deposits sometimes splendid uranium- yellow needles ; often how- ever it remains liquid for hours and even for days but suddenly solidifies when touched with a glass rod into a hard yellow crystalline mass.The new compound is most conveniently pre- pared by allowing the sulphocyanate to act upon the triethyl- phosphine in the presence of a considerable volume of ether. The product of the reaction being diffictdtly soluble in cold ether often separates in the crystalline state more fkequently as an oil which solidifies after some time. In order to ensure perfect purity it is only necessary to crystallize the compound once or twice from boiling ether. The numbers obtained in analysis characterize the new body as a combination of one molecule of triethylphosphine with one molecule of sulphocyanate of pheny'i The above formula is fully corroborated by the analysis of several well-defined salts which will be mentioned presently.The yellow crystals are insoluble in water. Alcohol both cold and hot dissolves them in almost every proportion. The best crystals were obtained by the spontaneous evaporation of the ethereal solution in high open cylinders. Some of these crystals were so well developed that Quintino Sella was enabled to sub- mit them to a detailed crystallographic examination an abstract of which I here insert '' System monoclinic :-Fig. 18. 100 001 = 61' 2'; 010 l10=4Ao 27'. Forms observed :-100 010 001 110 (Fig. 18). jooc ),to Combinations observed :-110 001 (Fig. IS). 110 100 001 (Fig. 20). 110 001 ; 100 010 (Fig. 21). OW- HISTORY OF THE PHOSPI%ORUS-BASES. 31I Fig. 19. Fig. 20. Fig. 21 iio \ Cleavage I00 easy ;cleavage I10fibrous.Hardness nearly that of gypsurn. If we endeavour to associate this compound with well-known bodies in order to obtain some insight into the probable arrange- ment of its proximate constituents both its formation and its deportment point to urea. Urea is generated by tbe combination of ammonia and cyanic acid; the yellow crystals are formed by the union of two compounds derived respectively from ammonia and cyanic acid. In urea the faculty possessed by ammonia of combining with acids has been preserved; the new compound likewise exhibits the sharply defined characters of a monacid base. Whatever constitution be attributed to urea must also be claimed for the new base. If urea be viewed as a moaacid diamine (CO)’/ CH,N20= H2 H!2 the yellow crystals present themselves as (CS)” C,,H,oNPS = (C,H,) (c2H5) (C6H5) The new compound accordingly belongs to the type urea it may be viewed as ordinary urea the oxygen of which is replaced by sulphur and the hydrogen by ethyl and phenyl whilst phosphorus has.taken the place of half the nitrogen. Regarded from this point of view the formation of the new compound presents considerable interest it offers the first example of DR. HOFNANN’S CONTRIBUTIONSTO THE the perfect substitution of the hydrogen in urea which had remained doubtful hitherto and illtistrates in a remarkable man- ner the persistence of the type urea under the influence of an almost overwhelming substitution. At the same time it deserves to be noticed that the corresponding oxygenated urea remains to be discovered.The new compound as already mentioned possesses the properties of a well-defined organic base. Insoluble in water it dissolves with the greatest facility even in very diluted acids giving rise in many cases to easily-crystallizable salts which are capable of double decomposition and from which the base may be reprecipitated by the careful addition of potassa or ammonia. ChZoride.-The solution of the phenyl-compound in warm con-centrated hydrochloric acid solidifies on cooling to a crystalline mass which when recrystallized from moderately warm water furnishes splendid cadmium-yellow crystals frequently an inch in length. Boiling water has to be avoided since it decomposes the substance.Even the dry crystals are altered at 100’; they must therefore like all the other salts of the base be dried in wacuo over sulphuric acid. The chloride is composed according to the formula C13H2,NPSC1= Bromide.-Both in preparation and properities precisely similar to the salt previously mentioned It contains (C S)” C,,H,,NPSBr = [H(C,K,) }Np] Br. (C2H5) (C6H5) PZatinurn-saZt.-The solution of the chloride furnishes with dichloride of platinum a light-yellow crystalline precipitate. Dilute solutions slowly deposit this salt in somewhat better-kmed crystals which are frequently grouped in lily-shaped aggregations It was found to contain I did not succeed in preparing the sulphate or the nitrate of the base.The phenyl-compound is rapidly decomposed under the influence of these acids ;it forms however beaiiti€djy crystallized salts with the iodides of methyl and ethyl. I have examined only the former of these compounds. Iodide-of-MethyZ-compound.-When iodide of methyl is poured into an ethereal solution of the urea the new compound is at once separated as a heavy oil which rapidly solidifies into a crystalline mass. The crystals dissolve in boiling water which on cooling deposits the iodide in splendid needles of a golden-yellow colour. These crystals contain Platinum-salt of the Methyl-compound.-The chloride obtained by treating the iodide with chloride of silver yields on addition of dichloride of platinum an acicular platinum-salt which may be recrystallized without decomposition from boiling water.Its composition corresponds to that of the iodide C,,H,NPSPtCl,= The iodide when treated with oxide of silver furnishes together with iodide of silver a very caustic liquid containing the corre- sponding oxide. The presence in this liquid of the compoundj is proved by the fact of the characteristic needle-shaped platinurn- salt being immediately reproduced when it is saturated with hydrochloric acid and mixed with dichloride of platinum. The free base is however readily decomposed. On boiling the dour of sulphocyanate of phenyl becomes at once perceptible; if ebulli- tion be continued until the dour has disappeared addition of hydrochloric acid aud dichloride of platinum no longer furnishes the difficulty soluble needles.In their place large well .developed orange-yellow octahedra are deposited on evaporation which by analysis mere found to be the platinum-salt of methyl-triethyl-phosphonium. 3 14 DR HOFMANN'S CONTRIBUTIONS TO THE The free methylated phenyl -base then simply splits by ebulli- tion into sulphocyanate of phenyl and oxide of methyl-triethyl- phosphonium. When the solution is boiled by itself the sulpho- cyanate is separated as such; when it is boiled in the presence of oxide of silver the sulphocyanate is partly at least destroyed the alkaline solution becoming acid and exhibiting the presence of considerable quantities of sulphurio acid. This transformation clearly shows how feebly the proximate constituents are held together in the urea.The same instability is perceptible in the general deportment of the compound. Even extremely dilute nitric acid liberates the sutphocyanate of phenyl whilst the phosphorus-base is converted into the oxide. The chloride is one of the more stable salts of the urea but it is likewise readily altered on additioii of a large quantity of water the solution of the salt becomes milky the sulphocyanate of phenyl being sepa- rated in oily globuiles and now contains the chloride of triethyl.. phosphonium. On adding ammonia to the concentrated solution of the chloride the urea as already stated is separated with- out change and may be easily recovered by taking up with ether and crystallizing. If on the other hand the dilute solution be boiled with ammonia the turbidity perceptible in the com-mencement disappears again and after a few moments beautiful crystals of phenyl-su&hocarZlamide are deposited triethylphos- phine being simultaneously liberated On treating the chloride with potassa phenomena exactly analogous are observed ; the crystals which are separated are however d~henyl-szaI-phocarbamide 2 Tf a few drops of disulphide of carbon be added to the solution of the urea the liquid when gently heated assumes a deep red HISTORY OF THE PHOSPHORUS-BASES colour and deposits on cooling the beautiful ruby-red crystals (C,H,),P,CS, which I have mentioned in a previous paragraph of this paper The mother-liquor of these crystals furnishes on evaporation oily droplets of sulphocyanate of phenyl.The urea even when perfectly pure and dry cannot be preserved without undergoing a gradual alteration. If the crystals be left under a bell-jar containing atmospheric air they become dull and at last moist and sticky whilst a peculiar extremely disagreeable odour distantly resembling that of hydrocyanic acid becomes percepti- ble; at the same time a delicate net-work of fine needles begins to appear on the glass easily recognized as sulphide of triethyl- phosphine. The crystals of the urea fuse at 57'05 forming a yellow liquid which in consequence of incipient decomposition resolidifies but slowly and imperfectly. At loo" the phenomena just mentioned are much more distinctly observed and especially the smelling body is unmistakeably perceived.The peculiar smelling body is likewise almost overwhelmingly produced on evaporating the ethereal mother-liquor of the compound As yet I have not been able to lay hold of the possessor of this remark- able odour. The ethereal mother-liquor when evaporated leaves it brown syrup which after some time deposits large crystals of sulphide of triethylphosphine. Submitted to distillation this residue yields together with other products an additional quantity of the crystallized sulphur-compound. Transformations precisely similar are obaerved when the crystals of the urea in sealed tubes are exposed to a temperature of from 150" to 160'. The brown fused mass which is thus formed solidifies on cooling with crystalline structure ;the crysta!s how- ever are no longer the original compound but sulphide of triethyl-phosphine which is surrounded by another sgbstance The examination of this reaction has not yet been completed.The nature of the final product of the metamorphosis may however be anticipated in some measure by the results obtained in studying the deportmeut of triethylphosphine with subhocyanate of ethyl and sulphocyanate of ethylene which will be briefly mentioned in some of the following paragraphs. Action of Sulphocyanate of Ally1 ecpon Triethylphosphine.-To generalize the relations established in the preceding paragraph I DB. HOFiVANH'S CONTRIBUTIONS TO TH-E was induced to examine the deportment of the phosphorus-base with oil of mustard.The two bodies act upon each other with extraordinary violence ;the mixture turns brown but does not solidify either by cooling or by agitation. After some days how-ever the syrup yields brown crystals which are difficult to purify. The purification of the compound succeeds however without any difficulty when the reaction is allowed to take place in ether. In this manner a crystalline mass is easily obtained which requires only to be washed with cold ether and then once recrystallized from boiling ether. It has the formula The allyl-compound behaves in all respects like the phenyl-com- pound. It is insoluble in water but easily soluble in alcohol; the solution has a faintly alkaline reaction. It fuses at 68" and solidifies at 61O.At a higher temperature it is decomposed exactly like the phenyl-compound. In this case also a peculiar and if possible still more repulsive odour is evolved while crystals of sulphide of triethylphosphine separate in large quantity. The dlyl-com pound crystallizes with extraordinary facility. There is no difficulty in obtaining it in colourless transparent crystals half an inch in Jength and perfectly developed on all sides. I scarcely remember any other organic compound that crystallizes so readily. The crystals as appears from the measure- ments of Quintino Sella are isomorphous with those of the phenyl-compound. Sell a has corn-Fig. 22. municated to me the following details respecting his examination. cc System inonoclinic :-100 100 101=35" 42' ;001 101=29" 3'; 010,111 = 39O 22'.Forms observed :-100,001 110 TOl 301 712 (Fig. 22). 317 . HISTORY OF THE PHOSPHORUS-BASES. Fig. 23. Combinations observed :-001 100 110 (Fig. 23). 001 iOl 110 (Fig. 24) 100,OOl,TOl 110 (Fig. 25). 100 001 iOl Il0,ilZ (Fig. 26). i00,001 ioi ~0,301, iiz (Fig. 27). Fig. 24. Fig. 25. The form 112 is sometimes hemihedral. Cleavages 100 and 001 neat easy. Fig. 26. Fig. 21. The optid axes are situated in the plane of symmetry viz. 010 j their principal medium is perpendicular to 101 and their internal a.ngleis about 723”. The index of refraction of the ray vibrating parallel to the axis of symmetry is p= 1.657. Hardness less than that of gypsum.’’ 318 DR.HOFikfANN’S CONTRiBUTIONS TO THE Platinum-salt.-I have contented myself with verifying the formula of the allyl-urea by the analysis of the platinum-salt. The allyl -compound dissolves readily in hydrochloric acid and the solution when mixed with dichloride of platinum yields a light- yellow scaly precipitate having a silky lustre which fuses to a yellow oil in boiling water and is represented by the formula- r (CS)” CloH2,NPSPtC13= IH(C2H5) NP IC1 PtCl,. (C2H5)(C3H5) The allyl-base described in the preceding pages has the compo- sition of sulphocyanide of triethyl-allylphosphonium. I felt some interest in comparing the latter compound with the allyl-base. Iodide of allyl acts with the greatest energy upon triethylphosphine. The solid product of the reaction recrystallized from alcohol furnishes splendid needles of iodide of triethyl- allylphosphonium which by analysis was found to coutain- Treatment with chloride and oxide of silver yields the cor-responding chloride and hydrate.They resemble in every respect the tetrethylphosphonium-compounds. The chloride gives with dichloride of platinum an easily crystallizable octohedral platinuni- salt. The hydrate of triethyl-allylphosphonium forms with hydrosul- phocyanic acid a difficultly crystallizable salt which is easily soluble in water and differs as might have been expected eutirely from the all$-base which has the same composition. Behaviour of Triethykhosphine with the Sulphocyanates of Ethy2 and EthgEene.-I have in vain endeavoured to produce by the action of triethylphosphine on the sulphocyanates of methyl ethyl and amFl compound urea8 analogous to the allyl- and phenyl- bodies.It is true that these substances act upon triethylphosphine even at ordinary temperatures; in the case of sulphocyanate of HISTORY OF THE PHOSPHORUS-BASES. methyl indeed the action is very brisk but I did not succeed in obtaining definite compounds Sulphocyanate of ethyl remained for months in contact with triethylphosphine without depo-siting any crystalline compound. The non-production of these ureas cannot however excite surprise if we remember in how many respects and especially in the relation to ammonia the sulphocyanogen-compounds of ethyl and its homologues differ from those of ally1 and phenyl.When a mixture of triethylphosphine and one of the above- mentioned sulphocyanates is heated for some hours in a sealed tube to loo" an abundant crop of crystals of sulphide of triethyl-phosphine is deposited from the liquid. These crystals are sur- rounded by %t brown viscid substance soluble to a certain extent in water easily soluble with green colour in alcohol. In order to disentangle from this mixture the complementary product of the reaction the liquor was shaken with ether to separate the sulphide evaporated with an excess of hydrochloric acid and the residue redissolved in water wherr a quantity of the brown impurities remained insoluble. The filtered solution gave with trichloride of gold a dingy yellow precipitate which by treatment with sul- phuretted hydrogen reprecipitation of the separated chloride by trichloride of gold &c.ultimately assumed the characters of the pure gold-salt of triethylphosphoriium which was identified by analysis. The beautifully orange-yellow platinum-salt was likewise analysed. The action of sulphocyanate of ethyl upon triethylphosphine may be accordingly represented by the equation I have not been able to trace directly the hydrocyanic acid which figures in this equation but this acid appears unmistakeably in its products of decomposition. The brown substance which accom- panies the sulphide of triethylphosphine and the hydrate of tetrethylphosphoniam is rich in nitrogen boiled for some time with hydrochloric acid it yields abundance of chloride of ammo-nium.I have likewise examined the behaviour of disulphocyanate of DR. I~OFMAEN’S CONTRIBUTIONS TO THE ethylene with triethylphosphine. The reaction takes place with energy at ordinary temperatures When triethylphosphine is poured into a concentrated alcoholic solution of sulphocyanate of ethylene the liquid immediately solidifies to a dazzling white crys- talline mass of sulphide of triethylphosphine. It deserves to be noticed that the same decomposition takes place also when the substances are allowed to react in presence of anhydrous ether. The transformation which the sulphocyanate of ethylene under- goes under the influence of triethylphosphine is perfectly analogous to the change of the ethyl-compound when submitted to the same agent.Instead of a derivative of tetrethglphosphonium the sulpho- cyanate of ethylene produces the cyanide of a diatomic metal of ethylene-he;l.ethyl-d~pl2osphon~um SuIphoeyana te Triethylphos-Sulphide of of ethylene. phine. trie th yiphog-phine. Dicyanide of ethylene-hex-ethyl-diphosphonium. Owing to the low temperature at which the reaction is accom-plished the hydrocyanic acid is not changed in this case and may be recognised without difficulty by the ordinary reagents. The diphosphonium which is simultaneously formed was traced as platinum-salt exactly in the same manner as the tetrethylphos- phonium in the process previously mentioned. The product of the reaction freed as far as possible from the sulphide by repeated evaporation and ultimately by treatment with ether was precipi-tated by dichloride of platinum.The dingy platinum-salt was purified by treatment with sulphuretted bydrogen and reprecipita- tion. Repeatedly treated in this manner it assumed the character of a pure compound which on analysis gave numbers closely agreeing with tte formula Since I shall have to give a detailed account of the diphospho- niurn-compounds in one of the following sections of this inquiry I HISTORY OF TEIE PHOSPHORUS-BASES. need not for the present enter into further particulars regarding this reaction. In concluding this paragraph I may append a few remarks upon the deportment of sulphocyanste of triethy lphosphonium under the influence of heat.This salt is readily procured by dissolving triethylphosphine in hydrosulphocyanic acid. Submitted to the action of heat it is partly volatilized without decomposition the greater portion however is decomposed sulphide and the disul- phide-of-carbon-compound of triethylphosphine together with free disulphide of carbon appearing among the volatile products of the reaction while a brown ill-defined substance remains in the retort yielding when treated with an alkali an appreciable quan- tity of ammonia. I have not examined this change in detail but it is obvious that one of the direct products of the reaction is sulphocyanate of ammonium the further decomposition of which explains the appearance of the disulphide of carbon as well as the other products observed.The residue of course must contain the varied compounds generated by the action of heat on sulpho-eyanate of ammonium. Behaviour of the Arsines and Stibines with the Sukhocyanates of Phenyl and AZZyZ.-The facility with which the compound ureas containing nitrogen and phosphorus are formed induced me to attempt the production of analogous compounds with arsenic or antimony in place of phosphorus. I therefore treated sulphocyanate of phenyl and oil of mustard successively with triethylarsine and triethylstibine first at ordinary and then at gradually increasing temperatures in sealed tubes. But not one of these experiments led to the expected result. The arsines and stibines differ indeed in their chemical character much more from ammonia than the phosphines.Their incapability of forming saline compounds with acids is alone sufficient to render the formation of ureas containing arsenic and antimony somewhat improbable. When mixtures of triethylarsine with sulphocyanate of phenyl on the one hand and sulphocyanate of ally1 on the other were left to stand for some time at ordinary temperatures the liquid in both cases was found to be traversed by a small quantity of beautiful needle-shaped crystals. The crystals from both mixtures were found to be the same ; they were readily identified with the beautiful needles VOL. XIII Y DR. BOFMANN’S CONTRIBUTIONS TO THE which are gradually formed in triethylarsine when left in contact with atmospheric air.Behaviour of Triethylphosphine with Cyanates.-The formation of sulphuretted ureas containing phosphorus and nitrogeu led me to try whether the corresponding oxygen-compounds could like- wise be produced. When cyanate of phenyl is mixed with the phosphorus-base great heat is evolved indicating a marked chemical reaction. The mixture on coolirg solidifies into a mass of shining crystals which are insoluble in water nearly insolable in ether and dissolve with difficulty even in boiling alcohol. By recryetallizatioii from tha last-mentioned solvent the new body is easily obtained pure. The further examination of the resulting crystals proved however that they by no means consisted of the compound urea of which I was in search. From the analysis which I intend to give in connexion with other researches it appeared that the crystals still possessed the composition of cyanate of phenyl that indeed they were cyanurate of phenyl.The triethylphosphine in this case appears to induce nothing more than a new molecular disposition of the elements in cyanate of phenyl. The peculiar character of this metamorphosis may be perceived in the most beautiful manner by dipping a glass rod moistened with triethylphosphine into a considerable quantity of cyanate of phenyl. The liqiiid imme- diately becomes hot and solidifies after a few seconds into a shining crystalline mass of the cpanurate. Similar results were obtained by the action of the phosphorus- base on cyanate of ethyl. The two bodies may be mixed without evolution of heat and the mixture does not solidify ;but the trans- formation is soon indicated by the diminution of the penetrating odour of the cyanate.If as soon as the odour has disappeared the liquid be mixed with dilute hydrochloric acid which removes the free phosphorus-base the oil which floats on the surface quickly solidifies into a solid crystalline mass which when recrys- tallized from boiling water exhibits all thz properties of cyanurate of etfql.-When a stream of cyanic acid gas is passed through triethylphosphine the odour of the acid disappears while the phosphorus-base becomes turbid and yields a white deposit of cyanuric acid. Tn connexion with these experiments 1 have had occasion to HISTORY OF THE PHOSPHORUS-BASES.323 convince myself that cyanic acid gas and phosphoretted hydrogen do not act upon one another at least at ordinary temperatures. -I was ansions to ascertain mhet,her the peculiar actiori of the phos- phorus-base on the cyanates extended likewise to the cyanides. I found however that cyunide of methyl (acetonitrile) or cyanide of phenyl (benzonitrile) may be left for days in contact with tlie phosphorus-base at temperatures varying from lQQo to IliO" without experiencing the slightest alteration. Had these substances been changed under the above conditions like the cyanates theiretrans- formation into iuethyl- and phenyl-compounds corresponding to cyanethine might have been expected. Experimetzts in the Jfethyl-series,-The information which I have collected with reference to the phosphorus-compounds ha3 been almost exclusively obtained by the study of triethylphos-phine.In exceptional cases only have I worked in the methyl- series. Trirnethylphosphinc on account of its volatility is much less easily prepared than the ethyl- compound and especially much more difficult to preserve. This body is oxidized with such rapidity that it disappears from the hand of the operator during manipulation. Its odour moreover is insupportable for any length of time. 5Tevertheless I have made a few experiments with the methyl- compound a slight sketch of which may form the conclusion of this payer. The Phosphorus-derivatives of the methyl-series exhibit the most perfect analogy with the corresponding ethyl-compounds.Oxide of trimethylphosphine produces with iodide of zinc with dichloride of platinum and with trichloride of gold the homolopes of the several compounds obtained from the oxide of triethylphos-phine. When trimethylphosphine either pure or dissolved in alco!iol and ether is submitted to the action of disulphide of carbon all the phenomena are reproduced which I have mentioned at some length in describing the corresponding ethyl-base. The red crys- tals which are formed are somewhat paler much more volatile nrld much more readily altered. The disulphirte-of-carbon -compounds of the methyl- and ethyl-series exhibit in their properties the same relation which obtains between the sulphides of the two series. Y2 324 DR.HOFXANN ON THE PHOSPHORUS-BASES. The formula C,H,P S = (CH3)3PjCS was established by analysis. The red crystals are changed with the utmost facility into sul-phide of trimethylphosphine. In the hope of forming fine crystals similar to those obtained with the ethyl-compound a solution of the red crystals in warm ether was allowed to cool in a tall open cylind_er. When the solution was examined next morning it had become colourless leaving upon spontaneous evaporation the beautiful crystals of the sulphur-compound. The sulphocyanates of phenyl and ally1 readily combine with trirnethylphosphine. The reaction is even more powerful than with the ethyl-base. The urea-body which trimethylphosphine produces with sulphocyanate of phenyl is a liquid which Ihave not been able to obtain in the solid state.Directly prepared from the constituents or separated from one of its crystalline salts it forms a slightly coloured oily liquid soluble in water diflicultly soluble in ether readily soluble in alcohol. On adding concentrated hydrochloric acid to the oil it gradually solidifies to a crystalline mass of sulphur-yellow delicate hair-like needles which may be recrystallized both from water and from alcohol. I have fixed the composition of this phosphoretted urea by a chlorine-determina- tion in a chloride of the composition The brown liquid which is formed with considerable evolution of heat when trimethylphosphine is brought in contact with mustard oil gradually deposits well-formed transparent colourlevs prisms the habitus of which resembles that of the corresponding -ethyl-compound.The crystals were not analysed but there can be no doubt that they were the methylated phosphorus-urea of the allyl-series (CS)” C,H,,NP = (CH,) ((333) (C3H5) BOLLEY ON GALLOTANNlC ACID Phosphoretted hydrogen is without action on the sulphocyanates of phenyl and allyl. In concIusion I beg to thank Drs. A. Leibius and M. Holz-mann for their assistance in some of the experiments connected with this inquiry.

ISSN:1743-6893    

DOI:10.1039/QJ8611300289

出版商:RSC    

年代:1861

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325 BOLLEY ON GALLOTANNlC ACID XXV1.-On the Discrepancies in the Statements of Pelouze and F. Mohr respec fing the Solubility of Gallotannic Acid in Ether. BYPROFESSOR BoL L E Y. FORthe extraction of tannic acid from coarse gall-nut powder in his cc Displacement Apparatus,’’ Pelouze recommends the use of ordinary not absolute ether. The liquid which then runs off separates into two layers the lower of which is thickish while the upper is mobile and less coloured. The lower liquid contains the tannic acid and is regarded by Pel o u z e as a solution of tannic acid in water; the upper liquid is stated to be ether holding in solution small quantities of tannic acid colouring matter &c. Mobr in his commentary on the Prussian Pharmacopeia decidedly contradicts this statement.His view of the matter has found its wq into most Manuals of Chemistry articles in Chemical Dictionaries &c. and is generally received as correct. He regards the lower stratum of liquid above-mentioned as a concentrated solution of tannic acid in ether and the upper as ether which has dissolved only a small quantity of tannic acid. The two layers he maintains are not soluble one in the other. If this be so it affords another example of a condition hitherto known to exist in one instance only (that of coniine) in which the solution of a body in a certain solvent is not dilnted by contact with that same solvent. In spite of this auomaly Mohr’s statement has been adopted without experimental verification. Mohr rests his view on an experiment described by himself.On treating tannic acid with anhydrous ether he obtained the tbickish layer already menr BOLLEP ON GALLOTAEEIC ACID. tioned and above it there floated a stratum of ether containing only a small quantity of tannic acid. I have likewise examined this peculiar phenomenon. I find that anhydrous ether (previously decanted several times over chloride of calcium boiling at 34.9' C. and having a specific gravity of 0.728 at 11*25°C.) takes up but a very small quantity of tannic acid indeed scarcely any (0.206 p. c. at 5" C.) Rhile the greater part of the tannic acid remains in the liquid in the form of a dry compact powder. On mixing the ether with half its yolurne per cent. of water the thickish liquid is formed.The ether-the upper layer -when mixed with a little water takes up rather more tannic acid than the anhydrous ether. 1 find that the upper layer-pure ether with 1vol. p. c. of water-takes up 1.2 p. c. tannic acid. This result appears to confirm Pe'touze's view. It is not how-ever true that the syrupy layer is a concentrated aqueous solution of tannic acid. On carefully removing a portion of this liquid so that none of the upper stratum may mix with it introducing it into a retort and distilling with good condensation considerable froth- ing takes place at first and ether passes over followed by water the two liquids forming layers of equal depth in a cylindrical receiver. If a little water be added to these two liquids a third layer is formed mliich rests between the two and is therefore insoluble both in ether and in water.This behaviour appears to me to re,ider probable the existence of a chemical compound of tannic acid ether and water possibly an acid ethyl-salt constituted like ethyl-sulphuric acid that is to say a tunnute of ether and water. There is a practical deJuctior.1 from these experiments which deserves to be mentioned. The behaviour of pulverized and well dried tannic acid to ether is so peculiar that it may be used as B test of the presence of water in that liquid. In anhydrous ether the powder remains quite unaltered but in hydrated ether it cakes together or deliquesces to a thickish syrup according to the amount of water present and the quantity of tannic acid added. Very small quantities of tannic acid give a distant reaction.

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DOI:10.1039/QJ8611300325

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年代:1861

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327 XXV1I.-On the Gotouring Hatters of Persian Berries and on certain general relations of Yellow Vegetable Dyes. BYPROFESSOR Bo L L EY a THEchemical investigations hitherto published respecting Persian Berries (Yellow berries graines d'Avignon Krautzbeeren) may be epitomized as follows :-Kane* distinguishes two colouring matters (a). Chrysorhamnin a yellow substance 6hich may be extracted by ether crystallizes in needles is nearly insoluble in cold water but easily soluble in ether. It contains according to the mean of two analyses 58.02 per cent. of carbon and 4.70 p. c. hydrogen and is said to be decom- posed by solution in hot alcohol or water and boiling of the solu- tion yielding another colouring matter (b) called Xanthorhamnin which is soluble in water and alcohol but insoluble in ether and when dried at 320'F.contains 52-55 C. and 5.15 H. Gel1 atly'f obtained with ether neither chrysorhamnin nor any other characteristic substance but with alcohol he obtained a yellow substance crystallizing in needles easily soluble in water whether cold or hot insoluble in ether and containing (when dried at 100' C.) 52.10 % C. and 5.78 H. This body he regarded as xanthorhamniri in a tolerably pure state. It is decomposed by heating with dilute sulphuric acid yielding together with glucose a body called Rharnnetin soluble in water alcohol and ether and containing 59.41 %C. and 4-38H. H lasi w e t z,$ in his paper on quercitrin makes some observations on Gellatly 's experiments chiefly however with reference to the elementary analyses.The nature of his suggestions may be under- stood from the following table :-Percentage of carbon and hydrogen in Quercitrin at 100" according to Bolley (1841)according to Hlasiwetz (1859) Kane's Xanthorhamnin. Gellatly 's Xanthorhamnin. C = 52 49 52.55 52-10 H = 5.03 5.15 5.78 Riga u d's Querce tin. C = 59.23 Chrysorhamnin. 58*02 Glellatly'sRhamnetin. 59.41 H = 4.13 4.70 4.38 * Phil. Hag. July 1843,p. 3. .I.Edinb. New Phil. Jour. vii 252. 2 Ann. Ch. Pharm. cxii 96. BOLLEY ON PERSIAN BERRIES. H1 asi w et z regards xanthorharnnin as identical with quercitrin and rhamnetin as identical with quercetin but he has not made any original researches on Persian berries. With the view of clearing up some of the above-meutioned dis- crepancies I have likewise made an investigation of Persian berries.In the first place I must observe that I obtained an abundant extract with crude ether (this may perhaps explain the differences between the statements of Kane and Gellatly). This extract after the ether had been evaporated the residue taken up by alcohol the solution filtered and the alcoLol evaporated with addition of water,-yielded stellate groups of yellow needles which were not altered by repeated solution boiling and precipitation. I analysed two different portions of this substance and obtained from the one C = 58.87 per cent. H = 4.66 , and from the other which was dried for a longer time at about 120"c. C = 60.239 per cent.H = 4.180 , These crystals are somewhat soluble in pure ether sparingly in water easily in alcohol. Their solution gives with neutraE acetate of lead a brick-red precipitate; with nitrate of silver a blood-red liquid and afterwards reduced silvw. I found some time ago that the lead precipitate is peculiarly characteristic of quercetin and I have now to make a similar observation respecting the silver reaction quercetin behaves both with lead and with silver solutions precisely:in the manner just described. The crystallized colouring matter which I obtained by the above process is beyond all ques- tion identical with quercetin. The peculiar interest of this fact is that it demonstrates thepre-existence in a vegetabk substance of a product of the decomposition oJ quercitrin.Chrysorhamnin (which Gellatly did not obtain) is perhaps the same as quercetin; but from the preceding observations it appears doubtful whether this body can easily decompose and yield a substance like that which Kane describes under the name of xanthorhamnin. If therefore as Hlasiwetz sup-poses rhamnetin is identical with quercetin it follows that BOLLEY ON PARAFFIN. decomposition is not necessary to the production of rhamnetin. Or may it not be possible that this decomposition takes place spontaneously in some kind of yellow berries ? Several varieties of these berries are in fact distinguished according to their appearance and their origin. This assumption which is by no means improbable may perhaps serve to reconcile some of the contradictions in the statements of Kane and Gella tly.

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329 BOLLEY ON PARAFFIN. XXVIII.-On a hitherto unobserved source of Paraps. BY PROFESSOR €3 OLLE Y. MASSES of naturally separated paraffin have been found in deposits of rock-oil e. g.,at Borystow in Gallicia; and Ozokerite Scheererite Idrialin &c. afford proof that hydrocarbons differing considerably in melting point and chemical composition occur ready formed in nature; but paraffin which occurs in tar and in certain mineral substances used for the production of heat and light has hitherto been regarded a product of the action of heat. In the Technical Laboratory of the Swiss Polytechnic School researches are at present being made on certain kinds of coal used for the production of illuminating gas; and one result of these researches easily detached from the rest I am now about to communicate.Boghead shale-which according to Geppert is not a true coal -has been examined by several chemists with reference to the quantity and composition of the residue which it leaves when heated and the nature of the volatile products. I have endea- voured to ascertain the nature of some of its proximate constituents by exhausting them with various reagents. A kilogramme of pulverized Boghead camel coal yielded to alcohol 2.14parts of solid extract residue; and to ether after drying 2-63pts. The alcoholic extract presented less interest than that obtained with ether which wasunctuous to the touch and not very:deeplycolourd I found that it could be redissolved in ether and decolorised by agitatip with animal charcoal.After this treatment however the residue exhibited by elementary analysis a quantity of oxygen amounting to 11 per cent. and gradually turned yellovish when BOLLEY ON PARAFFIN. heated for some time in the water-bath above its melting point. It sustained a slight loss by boiling with soda-lye and the undis- solved portion melted at 41" C remained colourless when heated solidified in crystalline laminae was insoluble in water sparingly soluble in alcohol somewhat more soluble in ether. The analysis of this residue gave Carbon . . . . . 86.33 per cent. Hydrogen . . . . 13.32 , 99.65 The melting point of paraffin was found by- Beich enbach to be 43' C. We know however that different samples of paraffin both natural and artificial melt some at higher some at lower points so that this circumstance need not prevent us from regarding the substance in question as paraffin.To me it appears probable that paraffin exists as such in several of the materials from the distillation-products of which it has hitherto been prepared such as peat shale lignite &c. and the process of separation just described affords a convenient method of testing such substances with reference to their utility for the preparation of paraEn which has hitherto been done exclusively by dry distillation. I must further remark that from two sorts of coal which I examined in this vay I obtained not paraffin but extracts more of the nature of asphalt. It is commonly stated that the non-existence or the rarity of occurrence of paraan in coal-tar is attributed to the great heat employed in the distillation. May it not rather be due to the fact that true coal does not contain parafin ready formed and therefore cannot yield a tar containing paraffin?

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XXIX.-Note of the Action of Chloride of Ethyl upon Ammolaia. BY CHARLESEDWARD GROVES. IT has often struck me as remarkable that while the deportment of ammonia with the bromide and iodide of ethyl had been so carefully studied the action of this substance upon the chloride of ethyl should scarcely have been noticed. Although the difficulty of manipulating so volatile a substance as chloride of ethyl promised but little advantage in the practical preparation of the ethyl bases ;it appeared nevertheless desirable to examine the reaction in order to complete the history of the formation of these substances. When chloride of ethyl sealed up in stout glass tubes with about three times its bulk of alcoholic ammonia-formed by nearly saturating alcohol with dry ammonia -mas digested for six or seven hours at the temperature of looo C.a large quantity of a white crystalline substance was deposited in the tubes apparently consisting of chloride of ammonium. The tubes were then opened and the contents thrown on a filter the white crystalline powder washed with absolute alcohol and the filtrate evaporated to dryness on the water-bath to expel alcohol and excess of ammonia. The residue was then dissolved in water filtered and submitted in a retort to the action of an excess of oxide of silver in order to set free the bases formed during the reaction. On heating the mixture the whole of the volatile bases passed over. The residue in the retort consisting of oxide and chloride of silver together with the hjdrated oxide of a non-volatile ammonium-base was thrown on a filter an4 washed with water until the washings were no longer alkaline.The filtrate neutralized with hydrochloric acid evaporated to a small bulk on the water-bath and filtered yields with bichloride of platinum a yellow crystalline precipitate which was washed with a small quantity of cold water and recrystallized from boiling water. 0185 grammes of substance yielded 0.0545 grarnrnes of pla-tinum; this shows a percentage of platinum equivalent to 29.4 pep cent. The formula-(C,H,),NCXPtCI requires 29.44 per cent. of platinum. The non-volatile base pro-duced in the reactian between chloride of ethyl and ammonia is 332 GROVES ON THE ACTION OF CIILORIDE therefore as might have been expected the hydrated oxide of tetrethylammonium The alkaline distillate containing the volatile portion of the bases was neutralizcd with hydrochloric acid evaporated to a small bulk on the water-bath and precipitated with an insufficient quantity of bichloride of platinum.The precipitate consisting of thin crystalline hexagonal plates was recrystallized from a small quantity of water to which it was found convenient to add a few drops of alcohol the salt being rather insoluble in dilute alcohol. 0.235grammee of substance gave 0.092of platinum. The formula-[(C*HJ H,W c1 Pt c1 requires 39.29 per cent. of platinum and the analysis gave 39.15 per cent. This result shows the existence of ethylamine among the volatile products of the action of chloride of ethyl upon ammonia.By successive partial precipitations and recrystallizations a COIL-siderable quantity more of the platinum-salt of ethylarnine was separated; until at last a very small quantity of another and more soluble salt was deposited from the mother-liquors. After a single recrystallization which was all that was possible owing to the amount being so small it was dried and analysed; and although some crystals of the ethylamine platinum-salt could be discerned by the microscope it gave results which approximated closely with the theoretical percentage of the diethylamine platinum-salt 0.170 of substance gave 0.062of platinum ; this gives a percentage of 36.47 of platinum. The formula- [P*HJ 23 NI Cl PtC1 requires 35.35 per cent of platinum.The above platinum deter- mination might also represent a mixture of the salt of ethylamine and triethylamine ; but the compound analysed although more soluble in water than the ethylamine-salt was not nearly so soluble as the salt of triethylamine ;moreover the latter substance is easily recognised by its crystalline korm. In addition to the salts above mentioned a small quantity of triethylamine was in all probability present among the products of the reaction of OF ETHYL ON AICfMONIA. chloride of ethyl upon ammonia ; but owing to the small proportion in vhich it existed and the known solubility of its platinum- compound I have not been able to establish its formation by experiment. The following equations represent the action of chloride of ethyl upon ammonia :-H3N + C4H,C1 = [ (C,II,),H,N] C1 2H3N+ 2C4H,C1 = [(C,H,),H,N] C1+ H4NC1 4H3N -+ 4C,H,Cl= [(C4H5)4 N] C1 + 3H4NC1.The experiments which I have described show a marked difference in the action of the chloride when compared with that of the bromide and iodide of ethyl. The chloride of ethyl produces almost exclusively the chloride of ethylarnmonium together with small quantities of the chlorides of diethylammonium and tetrethyl- ammonium. The bromide of ethyl according to the experiments of Dr. Hofmann gives chiefly the bromide of ethylammonium but also very appreciable quantities of the bromides of diethyl- and triethylammoniurn with but a small proportion of the tetrethyl- ammonium-compound ; and lastly the iodide produces the three volatile bases in about equal proportions but generally very appre- ciable quantities of the tetrethyl-ammonium-compound. The above experiments were performed in the Laboratory of Dr. Hofrnann.

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DOI:10.1039/QJ8611300331

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OF ETHYL ON AICfMONIA. XXX-On the Crystulline Form of &letallic Chromium. BY PROFESSOR BOLLEY. THEpreparation of sesquichloride of chromium and of crystallized metallic chromium by the methods recently given by Wohler,* is very easy. I entrusted the preparation to one of the students in my laboratory who obtained a product exhibiting the colour and lustre of the crystalline powder described by Wohler. WShler says of this It exhibits even with a magnifying power * Leichte Darstellungsweise des metallischen Chroms. (Ann Ch. Pharm. cxi 230.) ROLLEY ON CHROMIU ;91 of 50 crystalline aggregations having the form of fir-branches interspersed with very beautiful Rhombohedrons of great lustre and nearly tin-white colour.” I have examined the crystalline mass with a magnifying power of 85 and have found that it contains numerous fir-shaped arboresences such as W ohl er describes.But it was immediately apparent that the loose crystals dispersed through the mass were referable not to rhombohedral but to octohedral primary forms. These crystals are very frequently united in groups of four in the shape of a cross but the small- ness of the crystals precluded the possibility of measurement. My colleague Professor K enn-gott has had the goodness to determine the form of these crystals and finds that thcy are octohedrons belonging to the quadratic system. They are for the most part octagonal pyramids p p combined with a more acute ppamid s and a more obtuse pyramid 0. The p-faces are very deeply stri- ated; the o-faces very smooth and shining.It is well known that the crystalline forms of the metals bclong chiefly to two systems the ductile metals crystallizing in the tesseral the brittle metals in the rhombohedra1 system while some are dimorphous and exhibit forms belonging to both these systems. Hitherto tin is the only metal knonii to crystallize in another system viz. the quadratic. Boron likewise according to Quintino Sella,* crystallizes in the quadratic system. Chromium affords therefore the third example of an elementary body differing from most others in its crystalline form. It follows also from these observations that although certain compounds of chromium are isomorphous with the analogous compounds of iron this isomorphism does not exist in the metals themselves. * SuHe forme cristalline di alcuni sali di platino e dcl Boro adamantino par Quintino Sella. Torino 1857.

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DOI:10.1039/QJ8611300333

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335 XXXI.-Q3z a new Lead-salt corresponding to Cobalt-yellow. BY S. D. HAYES UNIVERSITY. EDINBURGH INthe course of some investigations on the cobalto-cyanide com- pounds I was obliged to use a quantity of cobalt-yellow the pigment discovered by M. Saint Evre in 1852.* All the methods described for preparing this salt are very tedious so that it became an object to find a more ready means. The best metliod hitherto given is to precipitate a solution of nitrate of cobalt with an excess of potash; then by passing a current of deutoxide of nitrogen (NO,) through the mass the cobalt-yellow is obtained but the greater part of the deutoxidc passes through without being absorbed ;the experiment requires hours ;and the amount of salt obtained is very small.As the composition of this body is considered doubtful it occurred to me that it might be made from peroxide of nitrogen (NO,) and after a few trials I obtained it very readily in large quantities and found tliat all the cobalt contained in a solution may thus be converted into cobalt-yellow. Two bottles connected and supplied with funnel tubes are about half filled with a solution of nitrate of cobalt to which potash slightly in excess is added. On passing a brisk current of peroxide of nitrogen through the liquid the mass in the first bottle soon changes colour and the pigment hegins to fall; by adding small quantities of potash occasionally through the funnel-tubes all the cobalt may be removed. The peroxide of nitrogen is most readily prepared by allowing a current of the deutoxide produced from copper and nitric acid in a small flask to mix with a current of common air from a gasometer in a dry empty bottle before passing into the cobalt-solutions The current of air can be regulated at the gasometer and the flask for generating the deutoxide can be easily removed and replenished when necessary.A solution of the car- bonate may be used instead of caustic potash for precipitating .the cobalt-solutions with the same results. A. Stromeyer when working iipou this salt endeavoured to obtain an analogous body with lead; he succeeded in getting a * Ann. Ch. Phys. [3],xxxviii 177 336 HAYES ON A NEW LEAD-SALT yellow solution by means of nitrite of potash apd acetic acid in 8 solution of lead but he then added cobalt which gave a pre-cipitate.* On treating a solution of nitrate of lead with potash and passing it current of peroxide of nitrogen through the liquid precisely as in making the cobalt-yellow I found that all the peroxide was absorbed and as the oxide of lead disappeared the solution became very yellow.Evaporating and crystallizing this I obtained large yellow prismatic crystals ;nitrate of potash crystal- lizes at the same time and if the peroxide of nitrogen has been passed through the lead too long nitrate of lead is formed. The yellow salt was easily separated and recrystallized. The bases were determined as sulphates in the analyses with the following results :-I. 0.7462 ems. pure salt gave 0*4200gmns.sulphate of lead and 0.0097 grms. lead = 0.319493 grms. oxide of lead and 0.2472 grms. sulphate of potash = 0.133545 grms. potash. 11. 1.4590 grrns. gave 0.6387 grms. oxide of lead and 0-25931 grms. potash. 111. 1.0271 grms. gave 0.43745 grms. oxide of lead and 0*1881 grms. potash. The nitrogen was determined as gas metallic copper reduced fiom the $ne oxide being used in the combustion tube with a little oxide at the fore end. The gas was collected and washedin a small apparatus then transferred to the eudiometer where it was measured. I. 0.1926 ems. salt gave 45.6277 cubic centimeters nitrogen at temperature 6*0°C.;and pressure 277*5millimeters = 16.30cc. at OOC. and 760mil. pressure = 0*204822grms. TI. 0.1958 grms. gave 16-23cc. at OOC.and 760 mil. pressure = 0*225983grms. The water was determined by combustion with metallic copper. I. 0.7834grms. gave 0.0274grms. water. IT. 0.9145 grms. gave 0°0314grms. water. 111. 0.4735 grms. gave 0*0177grms. water. Ann. Ch. und Pharm. xcvi 228. COBRESPONDING TO COBALT-YELLOW. I. 11. 1111. IV. Oxide of lead . . . 42.81 43.08 42.59 43.22 Potash . . . . . 17.90 17.77 28.31 ,I Nitrogen . . . 10.63 , 10.35 , Water . . . . 3.47 3.43 3.73 , Oxygen by difference 25.16 , 2P02 )) 100~00 100*00 The above analyses correspond to the following calculated formula :-PbO . . . 111.56 42.98 KO . . . 47.00 18-10 N . . . . 28.90 10.78 0 . . . . 64*00 2467 HO . . . 9-00 3.47 -7 -259.56 100.00 As this salt crystallizes out with nitrate of potash it is of about the same degree of solubility in either hot or cold water and the solution may be boiled for some time without any decomposition but it is readily decomposed by sulphuric hydrochloric or nitric acid giving off red fumes.With the common reagents it acts like nitrate of lead but with a solution of sulphate of cobalt it gives cobalt-yellow which goes down with the sulphate of lead. It loses its atom of water at IOO'C. but if the temperature be raised a few degrees higher the red fumes come off abundantly. The crystals are of a bright yellow colour and remain unaltered in the air. I am not yet prepared to give my salt any decided rational formula but its composition may be expressed in several ways as below.When 2N0 is passed over ZKO we get KONO and KONO, two distinct salts; but if ZNO, be passed over COOand KO as in the case of cobalt-yellow or over PbO and KO as in this salt we get only one salt of a double composition which we may write in like manner KONO, CoONO, or KONO, PbONO + HO. But there is an objection to this as cobalt-yellow is almost VOL. XIII. z BLOXAM ON THE insoluble in water. These salts may also be looked upon as double peroxides in which two equivalents of oxygen have been replaced by two equivalents of NO, thus but from the nature of the salts I hardly think that NO exists in them. However Gmelin describes a salt to which he gives the formula 2Pb0 NO, aq,,* and we express the composition of these salts just as well by writing them thus KONO, CoONO,; or KONO, PbONO +HOl This subject will be pursued and I hope to get several other salts which must give some reactions that will lead to the right rational formula These experiments were made in the laboratory of the Edin- burgh University.

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BLOXAM ON THE 338 XXXIL-On the Electrolytic Test for Arsenic and on the Preseqce of that Metal in certain Reagents. BY CHARLESL. BLOXAM. IN a former communication upon this subject which I had the honour of presenting to the Society,? it was shown that when a solution containing arsenious acid is mixed with diluted sulphuric acid and subjected to the action of the voltaic current arseniuretted hydrogen is evolved at the negative terminal aud that in this way very minute quantities of arsenious acid can be detected with great certainty even in the presence of large quantifies of organic matter and without adding any material tp the liquid which would interfere with its examination by other analytical processes It was also stated that arsenic acid did not respond to this test and that the presence of mercury in the liquid interfered very materially with the detection of the arsenic.* Handbuch. Bd. 3 s. 142. .t. See page 12 of this volume. ELECTROLYTIC TEST FOR ARSENIC. It is the object of this paper to show how arsenic acid may be brought within reach of this test how the interference of mercury may be prevented and how all chance of error due to the evolution of antimoniuretted hydrogen may be avoided. The form of apparatus recommended in the previous notice admitted of some obvious improvements. A tube-funnel has been added to permit the introduction of the liquid to be tested and the platinum wires communicating with the battery have been replaced by broad strips of platinum foil.If arsenious acid be converted into arsenic acid by boiling with hydrochloric acid and chlorate of potwsa and the solution be poured into the diluted sulphuric acid during the passage of the current no arseniuretted hydrogen is evolved; but if a few drops of' solution of sulphurous acid or of bisulphite of soda be poured down the funnel-tube a greenish yellow iridescent crust of tersul- phide of arsenic is almost immediately deposited at a little distance beyond the heated portion of the tube and is followed in most cases by the usual mirror of metallic arsenic. Since arsenic acid is reduced with great difficulty by sulphurous acid at the ordinary temperature it appeared probable that the effect was really due to the hydrosulphuric acid formed by the action of the nascent hydrogen upon the sulphurous acid and accordingly it was found that the introduction of a few drops of solution of hydrosulphuric acid into the electrolytic cell also caused the evolution of arwniuretted hydrogen.If an excess of hydrosulphuric acid be employed a deposit of sulphur is formed in the tube nearer to the orifice than the deposit of sulphide of arsenic from which it may be very easilr distin- guished by its much lighter colour and by its insolubility in a warm solution of sesquicarbonate of ammonia which readily dissolves the sulphide of arsenic. Three expesiments may be especially referred to in evidence of the certainty attending this process. 0.01gm. of arsenious acid was boiled with hydrochloric acid and chlorate of potassa and introduced into the electrolytic apparatus and the reduction-tube through which the hydrogen escaped xas heated to redness for 30 minutes without any appearance of deposit; but on adding 5 grn.measures of a solution of hisulphite of soda ayellow crust of tersulphide of arsenic made its appear-ance in 5 minutes and was followed by a distinct deposit of z2 BLOXAM ON THE metallic arsenic identified by its volatility and its solubility in chloride of lime. In a second similar experiment 10 grn. measures of a saturated solution of hydrosulphuric acid were poured down the funnel- tube instead of the bisulphite of soda. The crust of sulphide appeared within 10 minutes and that of metallic arsenic within 15 minutes.A third experiment was made with only 0.001 gm. of arsenious acid which had been boiled with hydrochloric acid and chlorate of potassa; within 13 minutes after the addition of 10 gra. measures of hydrosulphuric acid the yellow sulphide of arsenic appeared in the tube. It was found that however large a proportion of hydrosulphuric acid was poured into the decomposing cell the arsenic was still evolved the metal combining xith the nascent hydrogen in pre-ference to the sulphur. It appeared probable however that the addition of hydrosulphuric acid would at once precipitate any antimony or mercury present in the liquid under examination and would prevent their interference with the detection of the arsenic. One grain of tartar-emetic (0.36gm.Sb) dissolved in water was slightly acidulated with sulphuric acid mixed with an excess of hydrosulphuric acid and poured without filtering into the decom- posing cell in which the diluted sulphuric acid was undergoing electrolysis; .the evolution-tube was maintained at a red heat for 38 minutes without any deposit in the tube except a thin film of white sulphur. Another grain of tartar-emetic was then mixed with 0.01 grn. of arsenious acid which had been boiled with hydrochloric acid and chlorate of potassa and the mixture was treated with an excess of hydrosulphuric acid and poured into the same decomposing cell without interrupting the experiment. In 5 minutes yellow rings of tersulphide of arsenic made their appearance in the capil- lary reduction-tube; in less than 15 minutes a distinct crust had formed presenting exactly the same appearance as if no antimony whatever had been present.No deposit had been formed upon the negative plate. In the next trial only 0.001-gm. of arsenious acid was mixed with 1 grn. of tartar-emetic; the solution was boiled with hydro-chloric acid and chlorate of potassst diluted to oBe fluid ounce with ELECTROLYTIC TEST FOR ARSENIC. water saturated with hydrosulphuric acid gas and poured with the suspended precipitate into the decomposing cell. Within 15 minutes a distinct deposit of metallic arsenic was obtained which dissolved immediately in solution of chloride of lime. When 1 grn. of tartar-emetic and 0.01 grn. of arsenious acid were mixed with considerable quantities of bread milk and beer and the brown treacly liquid obtained by boiling with hydrochloric acid and chlorate of potassa and subsequent evaporation was mixed with excess of hydrosulphuric acid and poured into the decomposing cell deposits of metallic arsenic and of the tersul- phide were almost immediately formed in the tube.On collecting the dark precipitate after the operation it was easily identified as sulphide of antimony. In a second experiment of tbis description one-fourth of the brown fluid (containing 0.09 grn. Sb and 0.0025 grn. AsOJ was introduced into the decomposing cell without adding hydrosul- phuric acid when a very distinct mirror of antimony mas of course formed in the reduction-tube and a deposit of that metal was obtained on the negative plate.The reduction-tube was then changed and hydrosulphuric acid added when deposits of arsenic and its sulphide free from antimony were formed in the tube. To prove that with this modification of the test the presence of mercury no longer prevented the detection of arsenic experi- ments precisely similar to those above described were made respectively upon mixtures of 1 grn. corrosive sublimate with 0.01 grn. arsenious acid and 0.25 grn. corrosive sublimate with 0.0025 grn. arsenious acid mixed with white of egg bread milk and beer when no difficulty whatever was found in the detection of the arsenic. The solution containing chloride of mercury and arsenic acid was electrolytised for half an hour without the slightest appearmce of arsenical deposit in the heated tube the mercury being deposited abundantly upon the negative plate; but on the addition of solution of hydrosulphuric acid a crust of metallic arsenic was soon obtained.* * It will be evident that this method of converting the arsenic into arsenic acid and precipitating; the antimony and other metals by hydrosulphuric acid in the cold may he employed with advantage in Marsh’s test ; the solution containing the argenic acid must be filtered however before introduction into the evolution bottle as the suspended sulphide of antimony was found to be immediately decomposed in BLOXAM ON THE In order to ascertain whether the occurrence of putrefaction in an organic mixture containing arsenious acid would interfere with its detection by the electrolytic test an experiment was made with 0.001 grn.of arsenious acid mixed with meat white of egg beer bread and milk and allowed to putrefy for nearly twelve months. No difficulty was experienced in detecting the arsenic. I am very desirous of convincing myself that reliance may in all cases be placed on this process for the detection of arsenic by operating upon organic matters exactly similar in their nature and quantity to those often submitted to the chemist in judicial inquiries but have hitherto been unable to do this iu. consequence of the difficulty of procuring hydrochloric acid so pure that when examined in the large quantity required for the disintegration of considerable masses of viscera it did not afford any indication of the presence of zrsenic.Believing that I possessed a quantity of sulphuric acid perfectly free from arsenic I employed it for the preparation of hydrochloric acid; but even this sample was not found to be absolutely free from the impurity and on resorting to the sulphuric acid the examination of a large quantity at once proved the presence of a very minute proportion of arsenic which was more easily traced in the hydrochloric acid since the latter could be employed without inconvenience in larger quantity both in the electrolytic and in M arsh’s test. The production of sulphuric acid absolutely free from arsenic is now engaging my attention It has also been incidentally noticed in the course of these experiments that various samples of solution of potassa and of the solid hydrate contained very notable quantities of arsenic attributable probably to their having been prepared from nitre by the action of (arsenical) copper at a high temperature.A more important point for the consideration of the analytical chemist is the occiirrence of arsenic in the hydrosulphuric acid contact with zinc and sulphuric acid. In mixture containing a grain of tartar-emetic and one-hundredth of a grain of arsenious acid the latter was detected ft8 easily as if no antimony had been present by boiling with hydrochloric acid and chlorate of potassa precipitating the cold solution with exces8 of hydrosulphuric acid filtering and pouring into Marsh‘s apparatus.In Marsh’s test the use of eIectrolytised zinc was found to be attended with advantage in minute investigation on account of the very slow and steady evolution of gas. ELECTROLYTIC TEST FOR ARSENIC. prepared in the usual manner from sulphide of iron and diluted sulphuric acid. On passing the gas for 10 or 15 minutes through a reduction-tube heated to redness a distinct crust of sulphide of arsenic was formed nearer to the heated portion than the deposit of sulphur. That the crust really consisted of sulphide of arsenic was proved by its solubility in carbonate of ammonia and by its furnishing metallic arsenic when fused with carbonate -of soda and cyanide of potassium in a current of carbonic acid. This experiment was repeated with the same results upon different samples of sulphide of iron and sulphuric acid.That the arsenic was due to the sulphide of iron was ascertained by employing only so much of the purest sulphuric acid as gave no indication of arsenic in Marsh’s process. Water saturated with the gas when examined by Marsh’s and the electrolytic test was not found to contain arsenic. No arsenic was detected in the washed hydrosulphuric acid gas prepared from native sulphide of antimony and hydrochloric acid.

ISSN:1743-6893    

DOI:10.1039/QJ8611300338

出版商:RSC    

年代:1861

数据来源: RSC

摘要:

344 ANDREWS AND TAIT ON TEE On the Volumetric Relations of Ozone and the Action of the Elec-trical Discharge on Oxygen and other Gases. BY Thomas Andrews M.D. F.R.S. M.R.I.A. and Peter G. Tait M.A. (From the Philosophical Transactiordsfor 1860.)" 1. THEmolecular changes produced by the electric current or * discharge in certain compound bodies through which it is trans- mitted furnish some of the most interesting examples of the action of a decomposing force that have been discovered in later times. The discharge of the Leyden jar through fine wires or thin metallic leaves exhibited long ago the heating power of the current and the interesting experiments of the Dutch chemists afterwards showed that the disruptive discharge has the power of splitting up compound bodies into their constituent parts.The great invention of the pile of Volta by furnishing an abundant supply of electricity of moderate tension led subsequently to the important discovery of the polar decomposition of water and of other compound bodies. In the case of gases it has been known since the time of Priestly and Cavendis h that the spark-discharge has the apparently autagonistic properties of causing decomposition in some cases and combination in others Finally in our own day Schonbein made the fine observation that a new substance (ozone) alike remarkable for the activity of its properties and for the facility with which it is destroyed is formed by the action of the spark on pure oxygen gas in the electrolysis of water and in certain cases of slow oxidation.Our object in the present communication is to continue the investigation already begun by one of us,? of the properties of ozone by sitbjeciing it under varied conditions to a series of careful volumetric experiments. We hoped in this way to throw some new light on the relations of this singular body to oxygen by determining whether any and what change of volume occurs in its formation. Our expectations in this respect have not been disappointed. We have ascertained that when oxygen changes into ozone a great condensation takes place; so great indeed that it is almost incompatible with the existence of ozone as an allotropic form of oxygen in the gaseous state. This investigation has naturally extended itself to an examination of the effects produced * The substance of this paper was delivered as a Discourse to the Members of the Chemical Society of London by Dr.A n d re w s. $ Philosophical Transactions 1856 p. 1 or Quarterly Journal of the ChernicaI Society ix 168. VOLUMX:T&IC &ELATIONS OF OZONE. 345 by the electrical discharge upon other gases simple as well as com-pound ; and although from its great extent this part of the inquiry has as yet been only partially entered into some of the results already obtained are of considerable interest and will be referred to in the present communication. Bzfore proceeding further we must draw attention to the diffe- rence of action which in many cases we have found to exist between the spark or spark-discharge and the glow or silent discharge.When the former terms are employed in this paper they indicate a succession of brilliant sparks between two fine platinum wires usually at the distance of 20 millims (0.8inch) from each other and hermetically sealed into the tube containing the gas under observation. This form of discharge was obtained by connecting the free end of one of the platinum wires with an insulating stand provided with a brass ball which was brought within a short distance of the prime conductor of an electrical machine in high order while the free end of the other platinum wire was in connection with the ground. The silent discharge presented no visible character except a faint glow not visible by daylight at each metallic point and was obtained by connecting the first platinum wire not with the insulator but directly with the prime conductor.To avoid the mixture of the ‘‘ brush” with the silent discharge it was necessary to establish the connection firmly both with the conductor and with the earth wire; and in some cases where a full effect was required the machine had to be turned very slowly. The electrical machine employed was a small plate one (18inches in diameter) screwed down firmly to the floor of the apartment opposite to an open fire. On the prolongation of the axis of the plate a wheel 6 inches in diameter was fixed from which a belt passed to an iron wheel 40 inches in diameter revolving in ii wooden frame which was also fastened to the floor.By this arrangement the machine could be easily made to turn at the rate of 350 revolutions per minute. To maintain a regular and power- ful stream of electricity at this rapid rate of motion it was found necessary in addition to the ordinary cushions to hold with the haud against the plate a rubber covered with amalgam. When in ordinary working order the machine gave above 600 sparks per minute and in decomposing water produced in the same time 0.0002 cub. cent. of the mixed gases,* The ordinary forms of eudiometrical apparatus were found to be wholly inapplicable to this inqniry. We failed in discovering by their means whether even a change of volume occurs when ozone is produced from oxygen. To increase the difficulty the * Reports of the British Association for 1855 Trans.of Sect. p. 46. 346 ANDREWS AND TAIT ON THE experiments could not be carried on in presence of mercury or water as the former is immediately attacked by ozone; and the latter not only destroys it rapidly by contact but introduces a disturbing cause in the form of aqueous vapour exceeding in general the whole effect to be measured. In the apparatus now to be described these difficulties were overcome and very minute changes of volume determined with certainty. In figs. 1 and 2 the vessel in which the oxygen was contained is represented of different forms. It consists of a cylindrical tube ab having two fine platinum wires hermetically sealed iu opposite sides and terminating in a capillary tube cde of the form represented in the figure.The liquid in the limbs d e is hydrated sulplmric acid (HO SO,) and it is by the changes Fig. 1. Fig. 2. Fig. 3. \ in the level of this liquid that the alteration in the volume of the gas in abcis determined. In order to make the necessary correc- tions for changes of temperature and pressure during the interval between two observations a vessel filled with dry air of the same form and size as that employed in the experiment was read along VOLUMETBIC RELATIONS OF OZONE. 347 with it ;the reservoirs of both vessels being immerged in il large calorimeter as shown in fig. 3. To the first of these vessels we usually gave the name of primary vessel and to the second that of auxi2iary vessel.In order to correct for any slight difference in the size of the vessels or in the diameters of the capillary tubes simultaneous readings of both were made at different temperatures and a coefficient thus determined by means ofwhich the indications of the two vessels could be afterwards accurately compared. When the reservoirs were large the corrections so to be applied were frequently less than the errors of observation. The extreme delicacy of this apparatus will be evident from the following considerations If we take the case of a vessel with a lnrge r&ervoir (fig. lo) the changes in volume of Fig 1". the contained gas supposing the temperature to remain constant will be nearly proportional to the changes of pressure indicated by a barometer filled with sulphuric acid.As the height of such a barometer at the mean pressure of the atmosphere would be about 5500 millims. an alteration of e 1 millim. in the difference of levels of the acid in the siphon tube (de fig. 1) would correspond to a change of volume of about &th of the entire gas; but as it was easy to read to 0.5 rnillim. or even to 0.25 millim. the apparatus in this form enabled us to estimate a change of volume not ex- ceeding one-half or even one-fourth of that quantity. With a smaller reservoir (fig. Z) the indications of the apparatus were it is true not quite so delicate and a careful set of comparative readings with the auxiliary vessel was always required; but even here a change of volume amounting to not more than &th of the whole could be determined with cer..tainty The absolute change of volume of the gas cor-responding to a given change in the levels of the acid in the siphon tube (corrected in the first instance by the aid of the auxiliary vessel) was estimated in two ways; first by observing the change of level produced by raising or lowering the temperature of the water in the calorimeter through -a small number of degrees; and secondly by accurately determining at the end of the experiment the capacity of the reservoir and that of the capillary tube. The form of apparatus now described can only be employed when the entire change of volume of the gas does not amount in the course of the experiment to more than about one-tenth of the 348 ABNDREWS AND TAIT ON THE whole.When large changes of volume occur the free end of the siphon tube must be hermetically sealed so as to include a certain quantity of air from whose subsequent change of volume that of the gas in the reservoir can be readily calculated. This modification of the apparatus we have found to be very convenient in experiments upon the action of the spark and silent discharge on the compound gases. 2. The oxygen gas employed in the following experiments was prepared from fused chlorate of potash and to purify and dry it was passed through two U-tubes the first containing fragments of marble moistened with a strong solution of caustic potash the second fragments of glass moistened with sulphuric acid.The potash-tube was sometimes suppressed. In order to remove every trace of nitrogen the whole apparatus was placed in connexion with a good air-pump and a vacuum produced to the extent of at least half an inch while the gas was still being evolved from the Fig. 4. fused chlorate (fig.4). When the process of exhaus- tion was discontinued the gas soon filled the appa- ratus and was espelled through the mercury at the lower end of the long gauge. The operation of exhausting and refilling the vessel was performed three times in every experiment. Supposing the connexions of the apparatus to have been perfectly air-tiqht the nitrogen remaining after this triple exhaustion. could not have amounted to more than &th of ;he whole. This degree of accuracy was not it is true realized in practice but the oxygen gas prepared in this way did not contain &th of its F volume of nitrogen.The connexion with the air-w pump at a having been broken (the gas still continu- ing to pass freely over) the end of the tube was softened in a lamp and bent downwards at an obtuse angle so as to allow it to dip into sulphuric acid contained in a small dish as shown 349 VOLUMETRIC RELATIONS OF OZONE. Fig. 5. in fig. 5. The current of gas was now arrested by removing gradually the lamps from the chlorate of potash so as to allow the apparatus to Loo1 slowly. When the acid had ascended a short way in a c the vessel was sealed hermetically at 6 and after the acid had ascended to about the point c the vessel was removed and placed in the upright position represented in figs.1 and 2. It was sometimes necessary to expel a bubble or two of gas in order that the column of acid in the siphon tube might be in a convenieut position when the vessel was placed in the calo- rim et er . Previous to filling the vessels they were always cleaned by means of boiling nitric acid and subsequent washing with distilled water. They were afterwards carefully dried. To the success of several of the following experimeuts this precaution was indispen-sable. An auxiliary vessel having been filled in the same manner either with air or with oxygen the two vessels were placed in the calorimeter (fig. 3) and the difference of the levels of the acid in each carefully read.In our earlier experiments we generally used a cathetometer for this purpose but latterly we found it more convenient axid suaciently accurate to apply to the limbs of the siphon tubes a scale divided into millimetres. From the rapidity indeed with which the readings were thus made the results were found to be fully as trustworthy as those obtained with the cathetometer. When quantitative determinations were required the temperature of the water in the calorimeter and the height of the barometer were carefully noted. After the levels were read the free ends of the siphon tubes in both vessels were hermetically sealed. The primary vessel was then removed from the calorimeter and placed in connexion with the electrical machine to be exposed to the action either of the spark or silent discharge.When this 350 ANDREW8 AND TATT OM THE operation was finished the vessel was replaced in the calorimeter the siphon tubes were opened and the levels of the acid in the two vessels again read. In order to examine the effects of heat the reservoir of the vessel was placed in a sort of air-bath formed by suspending a long copper cylinder above a LESLIE'Sgas-burner the siphon tube being outside the cylinder fig. 6. In this way a temperature Fig. 6. of 30' C. which. was sufficient to destroy in a short time aJJ the ozone reactions was readily obtained. This temperature was eitimated without dif€iculty by observiug &e amount of compres-sion of the air ia the outer leg of the siphon tube.Our apparatus with a slight modification might in fact be employed as a ther-mometer for all temperatures belovrr that at which glass begins to soften. It will probably tend to perspicuity if we state before going further some of the general results of our experiments on the action of the electrical discharge on pure oxygen. VOLUMETRIC RELATIONS OF OZONE. I. When the silent discharge is passed through pure a.nd dry oxygen a contraction takes place This contraction proceeds at first rapidly but afterwards more slowly till it attains a limit which in one of our experiments amounted to &th of the original volume of the gas. 11. If n few electrical sparks be passed through the gas in this contracted state it expands till it recovers about three-fourths of the contraction; but however long the sparks are passed the gas never recovers its original volume 111.When electrical sparks are passed through pure and dry oxygen it contracts but to a much smaller extent than when acted on by the silent discharge. The oxygen is in fact brought to the same volume as when electrical sparks are passed through the same gas previously contracted by the silent discharge. IV. When oxygen contracted either by the silent discharge or by sparks is exposed for a short time to the temperature of 270° C. it is restored to its original volume and on opening the vessel the ozone reactions are found to have disappeared. The following experiments taken from a large number which gave similar results will serve to illustrate the foregoing state- ments.a. In a vessel whose reservoir had a capacity of 5 cub. cent. sparks were passed for ten minutes and produced a contraction of 5.9 millims. as measured by the change of levels of the acid in the siphon tube. By heating the vessel afterwards to 3OO0C. the levels were restored to within 0.1 millim. of their original position. With the silent discharge in the same vessel a contraction of 39.5 millims. (corresponding to about one-thirtieth of the volume of the gas) mas obtained in ten minutes. Of this contraction heat restored 38.7 millims. This slight difference of 0.8 millim. is pro- bably due to distortion of the vessel produced by heat. Again the silent discharge gave in ten minutes a contraction of 37.6 millims.of which sparks subsequently passed for seven minutes destroyed 29.7 millims. leaving 7.9 millims. undestroyed. p. In another vessel having a reservoir of the capacity of 0.8 cub. cent. active sparks gave in fifteen minutes 4 millims. of contraction. After fifteen minutes more of sparks there was no ad& tion a1 contraction. The silent discharge was now passed for fi€teen minutes and increased the contraction to 20 millims.; in fifteen minutes more the entire contraction was 31 millims. Four strong sparks reduced this to 22.5 millims, six or seven more to 16 millims. seven more to 11millims. and sparks continued for ten minutes left 4 millims. of permanent contraction. y. In a third vessel of about the same capacity as the last sparks gave a final contraction of 7.5 millims ;while the silent dia- 352 ANDREWS AND TAIT ON THE charge pushed to its limit increased the contraction to 90 millims.corresponding to about one-twelfth of the entire volume of the gas. This contraction was almost exactly destroyed by heat. Before leaving this part of the subject we should mention that when a full contraction is obtained by means of the silent discharge it will be found very slowly to diminish from day to day. We have not ascertained whether at the end of a very long period of time the original volume of the gas would be recovered. At 1000 C. the contraction diminishes much more rapidly than at ordinary temperatures. Thus it appears that the state produced by the electrical discharge is not permanent even at common tempera- tures and that it becomes more unstable as the temperature rises till at 270"C.it is rapidly destroyed. We next proceeded to examine the volumetric changes which occur when oxygen contracted by the electrical discharge is brought into contact with other bodies. The first body we tried was mercury the physical changes pro-duced on which by ozone are known to be very remarkable. Wheii a capsule containing this metal is broken in a tube of oxygen gas through which the silent discharge has been passed the mercury instantly loses its mobility and if gently shaken covers the interior of the tube with a brilliant mirror. As the action con- tinues the mirrored surface breaks up and the coating becomes converted into a blackish semipulverulent substawe.Unless the tube be very violently shaken the ozone reactions will not be entirely destroyed until the mercury has been for some hours in contact with the gas. To determine the volumetric changes a thin capsule filled with pure mercury and hermetically seded was placed in a vessel with a large reservoir of the usual form (fig. lo>,which was afterwards filled with dry oxygen. After the levels had been read the silent discharge was passed until a considerable contraction was obtained. The corrections for changes of temperature and pressure were as in other cases furnished by an auxiliary vessel. The free end of the siphon tube having been sealed the primary vessel was removed from the calorimeter and the capsule broken by a sudden jerk.The breaking of the capsule in this and other experiments was greatly facilitated by introducing into the vessel a small piece of thick glass tube which fell on the capsule when the vessel was shaken (fig. I" k p. 347). Viewing ozone as an allotropic form of oxygen in the gaseous state we expected that wheu mercury came into contact with it a Contraction would take place equal to the volume of the ozone which entered into combination with the metal. This anticipation has not been realized. After the rupture of the capsule the vessel was VOLUMETRIC RELATIONS OF OZONE. immediately replaced in the calorimeter and the levels read. Not the slightest diminution of volume was observed in any one of a large number of experiments; on the contrary an increase cor- responding to a change of 1 millim.in the levels generally occurred.. On allowing the vessels to remain in the calorimeter and reading the position of the acid in the siphon tubes from time to time the gas was found to expand steadily but slowly for some hours till from two-thirds to five-sixths of the contraction pro- duced by the discharge was recovered If the vessel was opened at any time while this expansion was going on the ozone reactions were always manifest; but when the expansion was at an end the ozone reactions had also ceased. If the mercury instead of being allowed tranquilly to act upon the gas was violently agitated after breaking the capsule a much smaller portion of the contraction was restored ;in some cases not more than one-sixth.Metallic silver in the state both of leaf and of filings gave similar results. The surface of the silver was partially blackened about three-fourths of the original contraction was recovered and the whole operation much more quickly terminated. As the above reactions were evidently complex the mercury and silver partly entering into combination with the gas while the compounds formed appeared to exercise a catalytic action we endeavoured to find an elementary body which would instantly destroy the ozone reactions and at the same time be without action on dry oxygen. After some trials we found that iodine possessed the required properties.We first ascertained that its vapour although visible at common temperatures has no appre- ciable tension. When a small capsule containing pure and dry iodine was broken in a vessel of the usual form filled with oxygen the levels of the acid in the siphon tube were not dtered. So slight also is the affinity of iodine for oxygen that on heatiiig the reservoir so as to volatilize a considerable portion of the iodine and afterwards allowing it to cool the volume of the gas underwent no change. On the other hand if ozone be present the iodine is immediately attacked a greyish-yellow compound is formed and all ozone reactions are instantly destroyed. The experiment already described with mercury was now repeated substituting iodine for that metal. On breaking the capsule the levels of the acid scarcely changed 1millim.although the original contraction amounted to 50 millirns. No subsequent expansion took place and on opening the vessel the ozone reac- tions had entirely disappeared. On the allotropic hypothesis these experiments and particularly the last lead to the conclusion that ozone must have a density at least fifty times as great as that of oxygen. This conclusion is VOL. XIII. 2A ANDREWS AND TAIT ON THE indeed unavoidable from the experiments just described unless it is assumed that at the same moment when one portion of the ozone combines with the iodine another portion changes back into oxygen and that these quantities are so related to one another that the expansion due to the one is exactly equal to the contrac- tion arising from the other.Such a supposition cannot however be considered probable. 4. In order to subject this remarkable property of ozone to a further examination two additional series of experiments were undertaken to a description of which we now proceed. In the first series a primary and an auxiliary vessel with large reservoirs were filled with pure and dry oxygen small capsules hermetically sealed and containing portions of the same solution of iodide of potassium having been previously placed in each. The silent discharge was passed through the primary vessel so as to pro-duce a considerable contraction amounting in different experi- ments to from 40 millims. to 80 millims. The levels of the acid in the siphon tubes of both vessels having been carefully read while the vessels were in the calorimeter the ends were sealed and the vessels shaken so as to break the capsules in both.In the primary vessel the iodide of potassium solution became instantly coloured dark brown from the iodine set free while that in the auxiliary vessel did not change. On replacing the vessels in the calori- meter and opening the ends of the siphon tubes the change in the levels indicated a considerable expansion in both. In the auxiliary vessel this expansion was due to the tension of the vapour of the solution of iodide of potassium alone; in the primary vessel the expansion ought to have been less than this on account of the absorption of ozone if the volume of that body were capable of measurement.In the following Table which contains the results of five very careful experiments made in this way the first column gives the amount of contraction produced by the silent discharge in the primary vessel previous to the breaking of the capsules; the second the temperature; the third and fourth the respective expansions in the primary and auxiliary vessels ; and the fifth the differences of the numbers in the third and fourth columns :-mm. 0 mm. mm. mm. I. 81.5 ll*OC. 68.5 70.0 -1-5 II. 62.2 13.5C. 79.5 80.0 -0.5 111. 72.2 8'7C. 50.7 52.0 -1.3 IV. 63.5 12.2C. 71.5 73.0 -1.5 V. 45.5 16.2C. 87*0 89.2 -2.2 VOLUMETRIC RELATIONS OF OZONE. The capacity of the vessels employed in these experiments was about 30 cub.cent. and the primary and its auxiliary were found in each experiment by careful comparative observations to work accurately together. The solution of iodide of potassium was purposely employed of different strengths in the several experi- ments. In I. it contained -&th part of iodide of potassium; in 11.Abth; in 111. +rd ; and in IV. and V. +th. In the two last the solution was slightly acidulated with hydrochloric acid in the others it was neutral. The capsules contained each about 0.7 grm. of these solutions. The agreement in the results of these experiments made with solutions of iodide of potassium so widely differing is very remark- able. We ought also to observe that direct experiments per- formed with great care showed that the iodine set free by the ozone in the primary vessel did not affect the tension of the vapour of the solution.Taking the mean of the above numbers the density of ozone as compared with that of oxygen must be expressed 011 the allotropic hypothesis by about the number 60 ; in other words ozone must be agas only about six times lighter than the metal lithium. If the small differences in the fifth column be due wholly or in part to accidental causes which is far from improbable a still higher number must on the same hypothesis be taken to express the density of ozone. In the last series of experiments the amount of iodine set free in the solution of iodide of potassium was determined by analysis and the weight of oxygen deduced therefrom compared with the weight of oxygen calculated from the volumetric change which had occurred in the formation of the ozone.We shall describe these experiments with some detail particu- larly as the methods employed will be found applicable to other cases of gas analysis where small changes in a given volume of gas have to be estimated. Before filling it with oxygen a sealed capsule containing a solu-tion of iodide of potassium was introduced into the primary vessel while the auxiliary contained the dry gas only. The silent dis- charge was passed through the former and the contraction care. fully observed. The capsule was then broken and the solution agitated in the primary vessel for a few seconds. The siphon tube was next cut off and the liquid carefully washed out and analysed by means of a weak solution of sulphurous acid the exact strength of which had been immediately before determined by observing the amount required to decolorize a solution containing a known weight of iodine.In some of the experiments the solution of iodide of potassium was slightly acidulated in the others it was neutral. In the latter 2A2 ANDREWS AND TAIT ON THIE case it was acidulated before being analysed. The results were the same whether the solution was taken in the neutral or in the acid state. For although oxygen gas acts upon an acid solution of iodide of potassium the action requires time and the contact in this case was only continued for a few seconds.* The formula by which we calculated the results of these experi- ments may be thus investigated Letf g (fig.l) be the mean level of the acid in the legs of the siphon tube; d e the levels at any time t being the temperature and II the barometric pressure corrected for temperature. Let also ge=fd=x and let H be the length of a tube similar to the siphon tube and whose capacity is equal to that of the reservoir and of the siphon tube to f. Let a be the height of a barometer containing the liquid in the siphon tube,p the pressure of the gas in the vessel and Tr the volume of the gas reduced to 0"C. and 760 millims. Then evidently 1+at paV--* H+x But p =11( 1 +T) t hence II(H +x)(1 +$) is a constant quantity. Taking the logarithmic differential we have 282 2x6~ a X NOW @ = is multiplied by -a quantity rasely exceeding &.an a' To this degree of approximation then at least 6v -+-@=ax (:-+-A) 0 (1.) V 1+at TI * BATJXERT has objected on this ground to aome of the experiments in a farmer communication made by one of us to the Society. We have found that in the cir- cumstances in which those experiments were performed about one-twentieth of the effecti was due to this cause; but as the oxygen acting on the Solution of iodide of potassium set free its equivalent of iodine the equality of the numbers given in that paper could not be disturbed by this actim. We have since that time by addi- tional experiments fully confirmed the statement that no water is produced in the destruction of electrolytic ozone by heat.VOLUMETRIC RELATIONS OF OZONE. If V, H, z,represent for the auxiliary vessel the quantities cor-responding to V H x in the primary we have since SV,=O -I-_. a6t *n-Sz,(a+H)1 2 . * . (2.) 1+at n If H,= H i. e. if the primary and auxiliary vessels be of similar dimensions we have at once from (1,)and (%)J If the vessels be not similar let then instead of (3.) we have Formula (3.) or (4.)gives the change of volume in the gas as deduced from the observed change in the levels in the siphon tube. For the estimation of the portion of the gas (8,V) taken up as ozone by the solution of iodide of potassium let C be the capacity of the primary vessel to f in litres s the number of measures of sulphurous acid required to decolorize the solution when washed out of the vessel S the number required to decolorize 1 grm of iodine.Then we have evidently as a sufficient approximation Is (1 +at)760 If we suppose ozone to be allotropic oxygen with a relative density e 1,then 8,V of oxygen contracts to 2on being changed e into ozone. Hence on this hypothesis In order to verify this method two similar vessels were filled with pure oxygen one containing a capsule filled with a neutral solution of iodide of potassium the other a capsule filled with an ANDREWS AND TAlT ON THE acidulated solution of the same salt and of precisely the same strength. The neutral solution was also introduced into the siphon tubes of both vessels.After breaking the capsules the levels were read and the vessels set aside for some days; at the end of which time it was found that a portion of oxygen gas had been absorbed in the primary vessel which contained the acid solution while no change had occurred in the other. The levels were now read again and the solution in the primary vessel analyzed. The weight of the oxygen absorbed as calculated by the fore- going formuh from the volumetric change was 0.0002188 grm. while its weight deduced from the analysis was 0.0002181 grm. The close agreement between these numbers shows that the method is susceptible of considerable accuracy. The following Table contains the results of six experiments made in the manner above described. The primary and auxiliary vessels were carefully constructed of similar dimensions and were found on trial to work accurately together so that formula (3.) was directlv amlicable.u J.1 I. IT. 111. IT. Tr. VI. mm. mm. mm. mm. mm. mm. 2x,. 31.5 -3'0 -18.5 -48.5 -51.0 39.0 2(x,+ 6x;). 31.0 18.0 -2.25 -6.5 -9.75 -8.25 22. 4.0 38.5 -0.5 16.5 72.5 65.0 2(x + 8%). -78.0 -2.75 -55.25 -5.0 -39.0 -27.5 C. 0.0338 0.0306 0'0288 0.0279 0.0269 0'0346 8. 9.1 5.4 5.7 5.1 4.5 4.5 w. gm. gm* gm. grm. w-I. 0.0268 0.0684 0.0442 0.06'74 0,0446 0.0621 S. 22.6 47.95 30.85 49.5 36.8 44.43 mm. mm. mm. mm. mm. IT. %O '772% '763.0 751.0 '747.2 751.0 t. llO.0 c. 13"-45C. 9O.1 c. 9O.8 C. 14O.O C. 14"-7C. 1 fT' 0*000025 0,000024 0 000025 0'000026 0'000027 0.000036 S,V 0.932 0,938 0'94'7 0.927 0.952 0.933 -.sv On comparing these experiments with the foregoing it will be observed that they do not give exactly the same result. In-terpreted as they stand they indicate a density for ozone if we may use the expression more than infinite inasmuch as the quantity of oxygen deduced from the analysis is less than that corresponding to the contraction observed. But although every precaution was taken to avoid all sources of uncertainty it is not improbable that this difference between the amount of oxygen deduced from the contraction and from the analysis may arise from a slight defectin some of the data particularly as it would only involve an error of the order of H&Fth of the entire gas. Taking the mean result of' the three series of experiments as VOLUMETRIC BELATLONS OF OZONE.359 they stand it gives on the allotropic hypothesis almost exactly an infinite density for ozone. 5. The commonly received statement that the whole of a given volume of dry oxygen gas can be converted into ozone by the passage of electrical sparks is erroneous. In repeated trials with tubes of different forms and sizes we fonnd that not more than one- twelfth of the oxygen could under the most favourable circum- stances be converted into ozone even by the silent discharge and a much smaller proportion by the action of sparks. But if the ozone is removed as fast as it is produced the conversion may be carried on indefinitely. An apparatus was constructed of the form shown in fig.7. At a b two fine platinum wires were hermetically Fig. 7. r-ng F sealed into the glass ; at c there was a solution of iodide of potas-sium and de was filled with fragments of fused chloride of crtlcium which allowed the ozone to pass freely but arrested the vapour of the solution ; so that while the discharge always took place in pure and dry oxygen the ozone was gradually absorbed. The volumetric change was measured by the readings of the sulphuric acid in the siphon tube fg sealed at g. The experiment was continued till five-twelfths of the oxygen (whose entire volume was about l2cub. cent.) was absorbed and the action was still going on. It was not considered necessary to persevere further as th3 iabour of turning the machine was very great.To produce the effect just mentioned the discharge from the machine in excellent order had to be passed through the tube for twenty-four hours. When the electrical discharge is passed through rarefied oxygen the phenomena are apparently the same as with the gas at ANDREWS AND TAIT ON THE the common pressure of the atmosphere. We filled a vessel with oxygen and exhausted it till the pressure was equal to 1 inch of mercury in the hope that in this rarefied state a larger portion of the oxygen might be converted into ozone than under greater pressures but this did not prove to be the case. We intend on a future occasion to pursue this part of the inquiry and to examine particularly the effects OF the electrical discharge on oxygen in different states of rarefaction and condensation.Ozone obtained by electrolysis gave results nearly similar to those already described. As the volume of the oxygen gas from which the ozone was derived could not in the cme of electrolytic ozone be observed directly it was estimated indirectly by placing three vessels in line and passing the same stream of electrolytic oxygen through them all. By heating the first and last vessels to 300' C and observing the expansion produced in each it was easy bo calculate the expansion which would have occurred in the middle vessel if it had been exposed to similar treatment. This expansion was assumed to be equal to the contraction vhich occurs when ozone is produced from oxygen by means of the electrical discharge.Finally the actual amount of ozone in the middle vessel was determined by introducing a solution of iodide of potas- sium and ascertaining by analysis the amount of iodine set free. The individual experiments with electrolytic oxone did not agree so well with one another as those performed with ozone prepared by the discharge. This arose partly from the very small quantity of ozone in electrolytic oxygen but chiefly from the irregularity in that quantity at different times even when the current was passing very steadily which made it difficult to ascertain with certainty the expansion due to the ozone in the middle vessel. Our earlier results indeed gave a measurable volume for ozone and as a first approximation we obtained the number 4 as express- ing its density.* But by multiplying our experiments and taking all possible precautions to ensure accuracy we found that electro- lytic ozone like that produced by the discharge has no appreciable volume.Ozone is not condensed at common pressures by the cold pro-duced by a mixture of solid carbonic acid and ether. A stream of electrolytic oxygen passed very slowly first through a U-tube surrounded by snow and salt and next through a spiral tube immersed in the carbonic acid and ether bath (-76' C.) under-went no change. The ozone reactions as the gas issued from the tube after exposure to this low temperature were as strong as before it entered the bath. *Proceedings of the Royal Society vol. viii p.498 and vol. ix,p 606 VOLUMETRIC RELATIONS OF OZONE. 6. Hydrogen prepared with care by the action of dilute sulphuric acid recently boiled on zinc and purified by passing through three U-tubes containing corrosive sublimate in solution hydrate of potash and aulphilric acid respectively and finally in order to remove the last trace of oxygen through a tube filled with metallic copper heated to redness was found not to be altered in volume, either by the sparks or by the silent discharge. It appears to be a much better conductor of electricity than oxygen. With Nitrogen prepared in the usual way by depriving atmo- spheric air of its oxygen by means of heated copper the results were also negative. Among the compound gases Carbonic Acid is rapidly decom- posed by the spark slowly by the silent discharge; in both cases expansion takes places.Cyanogen is at once decomposed by the spark with deposition of carbon (?); but presents so great a resistance to the passageof electricity that the action of the silent discharge could not be ascertained with certainty. Protoxide of Nitrogen is readily attacked by the spark with formation of hyponitric acid whose characteristic red colour is distinctly seen. The primary result of the spark action is expan-sion but on allowing the gas to stand it gradually contracts in consequence of the absorption of the hyponitric acid gas by the sulphuric acid in the siphon tube. It is impossible to determine the precise amount of the first expansion as a certain amount of absorption occurs at the same time; but in one imperfect trial the ratio between the expansion and the subsequent contraction was nearly that of 1:2.This corresponds to the conversion of 8 vols. of protoxidc of nitrogen into 4 vols. of hyponitric acid gas and 6 vols. of nitrogen. The silent discharge appears to produce the same result as the spark but as the action is slower the absorption interferes with any attempt to determine accurately the! primary expansion. Deutoxide of Nitrogen presents the interesting example of a com- pound gas which under the influence both of the spark and silent discharge undergoes like oxygen a diminution of volume. This is independent of the subsequent absorption of the hyponitric acid formed. This gas is remarkable for the facility with which it is decomposed by both forms of discharge.The passage of sparks for two minutes through a tube containing about 5 cub. cent, produced a contraction of the gas to nine-tenths of its original volume followed after some time by a contraction not quite double of the former from the absorption of the hyponitric acid gas. On continuing to pass sparks till the decomposition was finished and waiting till the hyponitric acid gas was completely absorbed the residue amounted to a little mope than one-fourth of the original ANDREWS AND TAIT ON THE gas. This residue consisted of a mixture of 11 vols. nitrogen and 1 vol. oxygen. It is evident that the final result is a little com- plicated but there can be little doubt that the action of the spark is to convert 8 vols.of deutoxide of nitrogen into 4vols. of hyponitric acid gas and 2vols. of nitrogen. This decomposition may be due to the immediate action of the discharge; or the deutoxide of nitrogen may in the first instance be resolved into equal volumes of nitrogen and oxygen the latter combiniug as it is formed with undecomposed deutoxide. Carbonic Oxide has givcn results of great interest the investi- gation of which has already occupied a considerable time although it is not yet completed. The principal facts have however been already ascertained and as they present some remarkable analogies to those already described in the case of oxygen we shall briefly allude to them here reserving the complete investigation for a future communication.The carbonic oxide was prepared by heating oxalic acid with an excess of sulphuric acid and absorbing the carbonic acid by means of a strong solution of hydrate of potash. The gas as it escaped from the end of the apparatus did not produce the slightest turbidity in lime or baryta water and was completely absorbed by an ammoniacal solution of' the subchloride of copper. On exposing this gas to the action of the silent discharge a steady contraction took place and the siirface of the positive platina wire became covered with a continuous deposit of a bronze colour. After some time a trace but only a trace of the same deposit appeared at the point of the negative wire. If after a contraction of 50 millims.or 60 millims. of the siphon tube had been obtained a few electrical sparks were passed through the gas the greater part of the contraction was its in the case of oxygen destroyed. Heat acted in the same direction but did not restore the gas altogether to its original volume. On continuing to pass the silent discharge the gas continued to contract and the deposit to increase on the positive wire. Por-tions of the same deposit were also scattered about the sides of the tube being probably thrown off from the same wire. The experiment was in some cases continued till the gas had contracted to about one-third of its original volume. To effect this contrac- tion the machine had to be worked for sixty hours. The residual gas consisted of carbonic acid oxygen and undecomposed carbonic oxide.A similar deposit was obtained when the discharge took place between gold instead of platinum wires. This deposit appeared to be soluble in water. Its quantity was so small that direct analysis was altogether impossible. Its composition may how- ever be determined by fixing with precision the ratios of the volumes of the carbonic acid and oxygen produced. We have suc- VOLUMETRIC RELATIONS OF OZONE. ceeded in devising a method by which this analysis may be effected even with less than 0.5 cub. cent. of the niixed gases but this part of the investigation is still unfinished. Atmospheric Air is the only gaseous mixture which we have exposed to the action of the silent discharge. Like pure oxygen it undergoes a diminution of volume ;but the operation is more quickly terminated and the contraction is less than with that gas alone.If after the passage of the discharge the vessel be set aside for some hours the contraction will be found to augment; and if the gaseous mixture be now again exposed to the action of the discharge a further contraction will take place. On the other hand heat destroys a portion only of the contraction at first pro- duced. All these facts are easily explained from the simultaneous formation of ozone and of one of the higher oxides of nitrogen and the marked influence of the latter when formed in arresting the formation of the former. To the same cause we have succeeded in referring an apparently anomalous state of oxygen produced by passing a stream of strong electrical sparks for some minutes through that gas containing a trace of nitrogen.The oxygen becomes by this treatment incapable of contracting or of changing into ozone under the action of the silent discharge and only recovers its usual condition by exposure to heat or by standing for some hours. If the nitrogen amounts to not more than &th of the entire volume this condition cannot be produced more than two or three times. At first we supposed it to be a new (passive) state of oxygen but we have now no hesitation in referring it to the presence of a trace of hyponitric acid gas produced by the electrical sparks. 7. It is perhaps premature to attempt a positive explanation of the facts now described regarding ozone.The foregoing investi- gation into its volumetric relations has for the moment rather increased than diminished the difficulty of determining the true nature of that body. To reconcile the experimental results with the view that ozone is oxygen in an allotropic form it is necessary to assume that its density immensely exceeds that of any known gas or vapour; being as we have seen according to the first and second series of experiments ($0 3 and 4) from fifty to sixty times that of oxygen and according to the third series (4 4) absolutely infinite. Even the former results would make it only six times less dense than the metal lithium and would place it rather in the class of solid or liquid bodies than of gaseous. The question may then be fairly proposed,-Can this singular body at common temperatures be actually a solid or liquid substance whose particles in an extremely fine state of subdivision are suspended in the oxygen with which it is always mixed? This question will scarcely we think admit of an aflirmative answer.Not only does ANDREWS AND TAIr ON THE ozone mixed as usual with oxygen pass through several U-tubes containing fragments of pumice moistened with sulphuric acid but it exhibits its characteristic reactions when left for many hours in tubes of this kind. Besides there is not the slightest cloud visible in a tube filled with oxygen even when one-twelfth of the gas has been converted into ozone nor does any deposit appear after long standing.Ozone may be formed under conditions which exclude the possi- bility of its containing as a constituent any element except oxygen or the elements of oxygen if that body should hereafter be shown to be compound. As has been before stated our experi-ments may be reconciled with the allotropic view and an ordinary density but still one greater than that of oxygen if we assume that when ozone comes into contact with such substances as iodine or solutions of iodide of potassium one portion of it retaining the gaseous form is changed back into common oxygen while the remainder enters into combination; and that these are so related to one another that the expansion due* to the former is exactly equal to the contraction arising from the latter.We do not however consider this supposition to be by any means probable nor can it be easily reconciled with the results (0 3) obtained when mercury acts on ozone. Tf we consider the conditions under which ozone is formed we shall find them to be different from those which produce allotropic modifications in other cases. Such elements for example as phosphorus or sulphur are modified by the action of heat and not by the electrical discharge. It is true at the same time that the destruction of ozone or on the allotropic riem its reconversion into oxygen by exposure to a temperature of 270' C. is appa- rently analogous to that action of heat whereby common phos- phorus is converted into the red variety. VCTithout rejecting the allotropic constitution of ozone although the results of our volumetric experiments are certainly difficult to reconcile with it it may not be uninstructive to consider whether the facts already known admit of a different explanation.As ozone is formed from pure and dry oxygen by the electrical discharge if it is not an allotropic form of oxygen the latter must be either a mechanical mixture of two or more gases or it must be a compound gas. It is perhaps scarcely necessary to consider the former hypothesis according to which oxygen in its ordinary state would be a mechanical mixture as atmospheric air is a mixture of nitrogen and oxygen. The contraction which occurs when the electrical discharge is passed through oxygen is at first sight indeed favourable to such a supposition inasmuch as the Combination of gases is usually accompanied either by a diminu- tion or no change of volume.But we have not been able to VOLUMETRIC RELATIONS OF OZONE. discover in its other reactions any facts which countenance this otherwise improbable view of the constitution of oxygen gas. Finally it remains to be considered whether in the formation of ozone oxygen does not undergo a more profound molecular chtinge than is involved in an allotropic modification whether in short this supposed element may not be actually decomposed. If, for the moment we confine our attention to the phenomena which present themselves when the electrical discharge is passed through oxygen this attractive hypothesis will be found to furnish a simple and plausible explanation of them all.It will be observed at once that the conditions under which ozone is formed from oxygen by the electrical discharge are precisely those under which other gases known to be compound are decomposed. The electrical current is one of very high intensity and therefore very favourable to decomposition when passed in the form of the silent discharge a large contraction takes place in the volume of the gas which is partially destroyed by a few electrical sparks and wholly by heat. With nitrogen and hydrogen no similar effects are observed the volume of these gases being quite unaffected by either form of discharge. The behaviour of carbonic oxide when exposed to the action of the silent and spark discharge corresponds remarkably to that of oxygen the latter form of discharge while producing itself only a limited contraction in carbonic oxide destroying a part of the contraction produced by the former.Again when deutoxide of nitrogen is exposed to the action of the same agents an immediate contraction takes place without any solid or liquid product being formed showing that in certain cases of gaseous decompositions the resulting gases occupy a smaller volume than the original compound. If we assume that oxygen is resolved by the electrical discharge into a new compound (ozone) containing the same constituents as the oxygen itself but in a different proportion and into one of the constituents themselves in the same manner as carbonic acid is resolved into carbonic oxide and oxygen or nitric oxide into hyponitric acid and nitrogen the results of our experiments will admit of an easy explanation.One of the simplest suppositions we can make for this purpose is that two volumes of oxygen con- sist of one volume of U and one volume of V united without condensation (U and V being the supposed constituents of oxygen) and that one volume of ozone consists of two volumes of 73 and one volume of V and further that by the action of heat iodine &c. ozone is resolved into U and oxygen. The appearance of ozone at the positive pole in the electrolysis of water and its formation by the agency of so active a body as ordinary phosphorus do not seem unfavourable to its being the mg ANDREWS AND TAIT ON THE result of decomposition.But the same observation will not apply to its production by the action of acids on such bodies as the peroxide of barium. We certainly should not have expected to see a body derived from the decomposition of oxygen produced uxder the latter circumstances and although the Eacts connected with its production in these cases have not been studied with precision yet there appears to be no doubt that ozone is actually formed. We must in conclusion add that the few attempts we have made to isolate either of the supposed constituents of oxygen have failed. We are still continuing to prosecute this inquiry and hope on a future occasion to lay before the Society the results of further experiments which are now in progress.Note added July 12 1860. Fig. 8. It having been suggested that a certain amouat of the contraction produced by the passage of the electrical discharge through tubes containing oxygen might arise from the action on that gas of the platinum wires or of finely divided platinum which as in Mr. Gassiot’s experiment might be thrown off by the action of the discharge we have made the following experiment in order to ascertain whether such an action could have occurred in the conditions under which we operated. Before describing the experiment it may be proper to state that in the passage of the dis- charge of the electrical machine there is no visible separation of metallic platinum as in that of the discharge from the induction coil nor other evidence of the wires being acted on; on the contrary both the wires and tube retain their original appearance after having been frequently exposed to the alternate action of the discharge and of heat.A vessel of the form represented in the annexed figure was filled with pure and dry oxygen. It differs from the tubes usually employed only by having the lower end of the reservoir drawn out into a capillary tube a 6. The platinum wires were inserted as usual and an auxiliary vessel of the same size and form was filled with dry air. After determining the comDarative range of the two vessels their VOLUMETRIC RELATTOKS OF OZONE. reservoirs were exposed in the apparatus before described to a temperature 800" C.in order to bring them as exactly as possible into the same condition. When they had cooled the levels of the acid in the siphon tubes were again read and the silent discharge was afterwards passed through the primary vessel till a contraction of twenty-seven millims. was obtained in its siphon tube. The extremity of the caellary tube of the reservoir was next cut off at a and the end of the siphon tube d which had the form repre-sented in the figure was dipped under sulphuric acid. The open end at a was now connected with an apparatus which supplied a slow stream of carefully dried air and this was allowed to pass till the ozone and oxygen originally contained in the tube were entirely displaced by the dry air. It is obvious that by this arrangement the ozone was removed while the platinum wires and the inner surface of the tube were left in precisely the same state as after the passage of the discharge.The tube was next sealed off at c by the application of the point of a fine blowpipe flame the current having been arrested so as to leave the usual column of sulphuric acid in the siphon tube. In sealing it care was taken not to allow the air in e to become heated. The vessel was again placed along with the auxiliary in the calorimeter and the levels read. The ends of the siphon tubes having been first sealed the reservoirs were exposcd to 300° C. An expansion should have taken place in the primary vessel if the platinum had retained oxygen capable of being disengaged at 300" C,; but this was not found to be the case.The change of level in its sulphuric acid siphon(corrected by the auxiliary) did not amount to 0.2 millims. a degree of accuracy rarely attainable in these experiments.

ISSN:1743-6893    

DOI:10.1039/QJ8611300344

出版商:RSC    

年代:1861

数据来源: RSC

摘要:

PROCEEDINGS AT THE MEETINGS OP THE CHEMICAL SOCIETY. November lst 1860. G. B. Buckton Esq. in the Chair. Rowlandson Cart mell Esq. 81 High-street Burton-on-Trent was elected a Fellow of the Society. Mr. H. C. Sorbp laid before the meeting several specimens illustrating the artificial production of Pseudomorphs. The following papers were read :-“ On the discrepancies in the statements of Pelouee and F Mohr respecting the solubility of Gallotannic acid in Ether,” by Professor B o11ey. “On a hitherto unobserved source of Parafin,” by PrQfessor Bolley. The following donations were announced :-‘‘ Jahrbuch der kaiserlich-koniglichen geologischen Reichsan- stalt in Wien,” No. 4 for 1859 from the Institute “ Jahrbuch der Central-Anstalt fiir Meteorologie und Erd-magnetismus in Wien,” Band VI; from the Institute.I‘ Denkschriften der kaiserlichen Akademie der Wissenschaften in Wien,” (math.-naturw. Classe) Band xviii. “ Sitzungsberichte derselben,” Band xxxix Hefte 1-5 und 1-12 from the Academy. Sitzungsberichte der kSniglich- baeyrischen Akademie der Wissenschaften,” (math.-physikalische Classe) 1860 Hefte 1 2 from the Academy. cc Bulletin de la Classe Physico-mathe’matique de 1’Acade’mie Tmpkriale des Sciences de Saint Pktersbourg,” Tome 1 Feuilles 10-36 from the Academy. cc Mernorie dell’ Academia delle Scienze dell’ Istituto di Bologna,” Tomi 8 9 e Parti I del Torno 10. PROCEEDINGB OF THE CREBIICAL SOCIETY. 369 cr Rendiconti dell’ Academia delle Scienze dell’ Istituto di Bologna 1857-58 e 1858-59 :” from the Academy.cc Boletin de la Societa de Naturalistas en Nueva Granada,” 1860 from the Society. ‘‘American Journal of Science and Arts,” for May July and September 1860 from the Editors. “Journal of the Franklin Institute,” June to October 1860 from the Institute. “Proceedings of the Academy of Natural Sciences at Phil- adelphia,” 1860 Nos. 6-12 fiom the Academy. “Proceedings of the American Philosophical Society,” 1858 and January to June 1859 from the Society. ‘‘Smithsonian Report,” for 1858 from the Smithsonian Institution. ‘‘First Geological Report of Arkansas :” presented through the Smithsonian Institution by the State of Arkansas. cc Canadian Journal,” July to September 1860 from the Canadian Institute.‘‘Memoirs of the Royal Astronomical Society,” Vol. XXVIII. cc Monthly Notices of the Royal Astronomical Society,” No. 9 for 1860 from the Society. ‘CQuarterly Journal of the Geological Society,” No. 3 for 1860 from the Society. cc Chemical News,” Nos. 29-44 from the Editor. c( Pharmaceutical Journal and Transactions,” July to October 1860 from the Editor. cc Journal of the Society of Arts,” Nos. 396 to 401,and 4041to 413 from the Society. cc Journal of the Photographic Society,)’ July to October 1860 from the Society. cc Literary Gazette,” Nos. 105 to 121 from the Publishers cc Proceedings of the Literary and Philosophical Society of Liverpool,’” 1859-60 from the Society. “On the Lines of the Solar Spectrum,” by Sir David Brew- ster and Dr.J. H. Gladstone; from the Authors. ‘<On the Electric light of Mercury,” by Dr. J. H. Gladstone from the Author. VOL. XLII. 2B 370 PROCEEDINGS OF THE CHEMICAL SOCIETY. November 15th 1860. Professor Brodie President in the Chair. The following Gentlemen were elected Fellows of‘the Society :-J. H. Player Esq. Oldbury near Birmingham; A. Norman Tate Esq. Runcorn Gap near Warrington ; Francis Valentine Paxton Esq. B.A. Christchurch Oxford ; George William Brown Esq. 131 Sanchiehall-street Glasgow ;Henry Brunner Esq. Royal Institution Laboratory Manchester. The following papem were read :-“ On the crystalline form of Metallic Chromium,” by Professor B ol 1 ey. ‘I On the colouring matter of Persian Berries,” by Professor Bolley.“ On the basic Carbonates of Copper,” by Mr. F. Field. Dr. Hofmann made a communication “On the Separation of the Volatile Ethyl-alkaloids.” The following donations mere announced :-‘< Om Sovandets Bestanddele og deres Forderling i Havet,” by G. Forchhammer from the Author. I‘ Recherches sur les ltapports reciproques des Poi& atomiques,” par J. S. Stass from the Author. c‘ Du Raisin considkr6 comme Mddicament,” par J. C. Herpin from the Author. Bulletin de la Classe Physico-math6matique de I’Acad6mie Impkriale des Sciences de Saint P&ersbourg,” Tome 11 feuilles 1-17 from the Academy. cc Quarterly Journal of the Geological Society No. 4,” for 1860 from the Society. cCElementsof Chemistry,” by William Allen Miller Part 11 ic Inorganic Chemistry :” from the Author On the Volumetric Relations of Ozone and the action of the Electric Discharge on Oxygen and other Gases,” by Thomas Andrews and P G.Tait from the Authors. c‘ Chemical News,” Nos. 46-49 from the Editor. ‘fPharmaceutical Journal and Transactions,” for November 1860 from the Editor. PBOCEEDINGS OF THE CHEMICAL SOCIETY. 371 ‘‘ Photographic Journal,” for November 1860 from the Photo- graphic Society . “Literary Gazette,” Nos. 122 123 from the Publishers. “Notices of the Proceedings of the Meetings of the Members of the Royal Institution,” 1859-60. ;‘ List of Members Officers &c. of the Royal Institution>” 1859. lC Additions to the Library of the Royal Institution,” from July 1859 to July 1860 from the Royal Institution.December 6th 1860. Col. Philip Y orke Vice-President in the Chair. Jam es €3 arr at t Esy. of Coniston Windermere Westmore- land was elected a Fellow of the Society:- A paper was read ‘‘ On a new Lead-salt corresponding to Cobalt-yellow,” by Mr. S. D. Hayes. Dr. Hofmann made a communication ‘c Ou the production of mixed Amines Phosphines and Arsines.” The following donations were announced :-‘‘Verhandlungen der naturforschenden Gesellschaft in Basel,” 2th Theil 4ter Heft from the Society. ‘‘Journal of the Franklin Institute,” for November 1860 from the Institute. “Journal of the Society of Arts,” Nos. 414419 from the Society. ‘‘ Pharmaceutical Journal and Transactions,” for December 1860 from the Society.“ Chemical News,” Nos. 50-52 from the Editor. “Literary Gazette,” Nos. 125-127 from the Publishers. <‘On the large Blasts at Holyhead,” by George Robert-son Esq. from the Author. 3 R2 372 PROCEEDINGS OF THE CHEMICAL SOCIETY. December 20th 1860. Professor Br o die President in the Chair. The following were elected Fellows of the Society :-Rev. W. R. Bowditch Wakefield; John L. W. Thu-dichum M.D. 65 South Audley Street. The following papers were read :-‘(Contributions to the Knowledge of the Laws of Gss-absorp- tion,” by Thomas €3. Sims. cc On Sugar in Urine,” by Dr. H. Bence Jones. ‘(On the Separation of Tellurium Selenium and Sulphur,” by Dr. Oppenheim. On Nitroprusside of Sodium,” by Dr.Oppenheim. The following donations were announced :-cr Abhandlungen der koniglich-baegerischen Akademie der Wissenschitften (mathematisch-phy sikalische Classe),” Band VIII Abtheilung 3. Sitzungsberichte deraelben,” 1860 Heft 11. “Denkrede an Alexander von Humboldt gelesen in der ijffent- lichen Sitzung der kFniglich-baeyerischen Akademie der Wissens- chaften,” am 28 Marz 1860 von C. F. P. von Martius from the Royal Bavarian Academy of Sciences. cc Ofversight af Kongl. Vetenskaps- Akademiens Forhandlingar 00 sextonde Argangen,” 1859 from the Swedish Academy of Sciences. ‘‘American Journal of Science and Art,” for November 1860 from the Editors. ‘‘Monthly Notices of the Royal Astronomical Society Vol. XXI No. 1 from the Society. ‘‘ Chemical News,” Nos. 52-54! from the Editor. “Journal of the Society of Arts,” Nos. 420 421 from the Society. ‘I Photographic Journal,” for December 1860 from the Photo-graphic Society “Literary Gazette,’’ N 0s. 128,129 from the Publishers.

ISSN:1743-6893    

DOI:10.1039/QJ8611300368

出版商:RSC    

年代:1861

数据来源: RSC