NOTICES OF PAPEM CONTAINED IN OTHER JOURNALS. Extract of a Leiter from Baron Liebig to Dr. Daubeny dated December 25 1857.* u I BAVE published a series of experiments on some properties of soils by Ghich I think I have completed the researches instituted by Professor Way respecting their capacity for absorbing the soluble constituents of manures. "My experiments were limited to those constituents which are presented to plants from natural sources and to the conditions necessary for rendering them soluble and absorbable by the roots. 'c I was a little astonished to find that the cause of this solubility did not appear to be traceable to circumstances attributable to the plant itself but that something inherent in its own organization must co-operate with the actual conditions in which it was placed in order to enable it to extract its food from the ground.''The potassa belonging to silicate of potassa is absorbed by all kinds of soil but not so the silicic acid accompanying it. If a solution of silicate of potassa be brought into contact with soils rich in organic matters the potassa is absorbed but the silica remains in the solution. "From a solution of phosphate of lime or of phosphate of mag- nesia in water saturated with carbonic acid soils absorb the phosphoric acid whilst they allow the lime still to remain in the solution. ((Thus the inference deducible from my experiments is that land plants do not receive their food from a solution of the ingredients already present in the soil but that they abstract or absorb it directly from the soil itself through the joint agency of water and of'a force inherent in their roots.'' Sometimes we find stones in meadows covered over with striae exhibiting a kind of network which is produced by the corrosive action of the roots of plants in contact with them. '(It has hitherto been assiimed that a plant possessed a decom-posing power as well as a secreting one. Thus when the potassa of sulphate of potassa or the potassium of the chloride became associ- ated with the vegetable organization we supposed that the salt had been decomposed within the plant and the sulphnric acid or chlorine eliminated by it. This power does not exist. The salts Communicated by Dr. Daubeny. EXTRACT OF A LETTER in question are decomposed by the soil and the plants all receive their food from elements in the same state of combination.“The experiments of Way constitute the foundation of a new theory of vegetable nutrition. “I moreover find that plants living in fresh water receive their food in the very same way as those which are marine. I examined the Zemna trisulca which grows on the surface of stagnant water a plant containing 16.6 per cent. of inorganic matter. I compared the analysis of its ash with that of the water in which the plant had grown from which it appeared that the plant and the water contain the same constituents but in very different proportions ; thus the ashes of the plant contained in 100 parts 16-82 of lime whilst the salts present in the water in 100 parts contained 35.00.Again the ashes contain . . 5 of magnesia the salts in the water . 12 Y, the ashes . . 13 of potassa the salts in the water about 4 , “Just then” (as I interpret Baron Liebig’s meaning) ‘(as algae absorb from sea-water the small quantities of iodine and of potassa present in it without regard to their amount as compared with other constituents so the lemna appears to do the same with respect to the constituents above cited a power of selection residing in the roots being in both instances evinced ‘‘ There is perhaps,” continues Baron Liebig (‘no mineral spring in the world which contains the amount of soluble salts present in stagnant waters. Compare for instance with a mineral spring the water of the River Thames that of the springs analysed by Hofmann Moller and Graham and that of the water (drain water) examined by Way which had drained through soil.Thus Thames water contains from 1.3 to 7.3 per-centage of potassa according to the spot from whence it is taken being richest in potassa where it had received the largest amount of animal matter as at Lambeth. In well-water the potassa it varies from 0.7 to 6.0 per cent. whilst not more than a trace is found in water which has drained through soil. “Owing to the eremacausis and decay of the many generations of plauts which have existed in stagnant waters their organic matter is resolved into compounds of oxygen (becomes oxygen- ated) and their inorganic constituents remain dissolved in the water itself thus rendering it rich in substances which are never found in equal proportions in the water of springs and rivers.” Such is the substance of Liebig’s letter to me with only siich alterations as I have thought proper to make in it in order to render his meaning more intelligible although in general the Baron’s English style is so good as to require but little correction.In the German paper he has likewise sent me a FROM BARON LIEBIG. reprint as I imagine of an article of his inserted in the AZZgemeine Zeitung more details are given and some facts added in corrobo- ration of the views which I have brought Before you. The experiments cited need not perhaps detain us as they do little more than confirm the conclusions arrived at by Professor Way with which we are already familiar.It does not appear however whether he adopts the view at present taken by Mr. Way namely that the retention of the alkaline ingredients by the soil is connected with an interchange of elements the salts of lime for instance being carried down with the acid whilst potasaa unites with the carbonic acid set at liberty. Be that however as it may the inference which Liebig draws remains unaffected; for it is evident that granting this to be the fact an affinity must be exerted by the soil for the newly-formed salt in order to prevent its being carried away by the water which percolates through it and being present in the drainage. Now what is this affinity? Liebig compares it to that which enables charcoal to retain the colouring matter of liquids within its pores or that which causes starch to unite with iodine ;but in any case something more than the action of water is necessary to overcome it or the new salts could not remain in the fallow for any time after they had been formed.This assisting force Liebig considers to reside in the roots and there are certainly many facts which tend to show that these organs operate not merely passively by imbibing any liquid that happens to present itself to them but that they possess an active and as it were a vital energy in absorbing some substances and in eliminating others. This indeed is precisely the same conclusion which I had myself arrived at so long ago as the year 1833 from experiments in which plants were watered with salts of strontia without absorbing any appreciable quantity of that earth; as will be seen by my Paper ‘‘On the Degree of Solution exercised by Plants with regard to the Earthy Constituents presented to their Absorbing Surfaces,” which was published in the Transactions of the LinnEan Society for that year.We may also thus explain why plants may be watered as has been done by myself with weak solutions of arsenic without being themselves affected or contracting therefrom any poisonous property; nor is this inconsistent with the fact that certain poi- sonous solutions such as the salts of copper or iron do find admittance into the tissue of plants because in these instances the vitality of the roots is in the first instance destroyed and thus the imbibition of the poison takes place as would occur even in dead matter by endosmose and by capillary attraction.It is at least certain that the water which trickles through a bed of soil contains far too small a proportion of the ingredients which the crop contains to be regarded as the source from whence HOFMANN AND CAHOURS the latter can obtain them as Baron Liebig has shown by a very simple calculation; and hence we are driven to attribute them to the constituents which Professor Way's researches have shown to be separated by and combined with the soil. Now as the latter will not impart them to water alone except in very small quan- tities it is at least evident that some power must reside in the roots which can assist in overcoming the chemical affinity between the soil and the inorganic matters which the plant assimilates.Such at least appears to be the conclusion to which Baron Liebig has arrived and as no notice seems to have been yet taken of his researches in any English Periodical I trust I shall be par- doned both by him and by the Society in thus bringing forward the substance of a private letter in which a short abstract of them is contained. Researches on the Phosphorus-Bases. By Augustus William Hofmann and Augustus Cahours. Abstracted from a Paper read before the Royal Society June 18. 1858. INa note on the action of chloride of methyl upon phosphide of calcium communicated more than ten years ago to the Institute of France,* M.Paul Thbnard pointed out the existence of a series of bodies which correspond to the compounds of phosphorus with hydrogen which may in fact be viewed as hydrides of phos- phorus the hydrogen of which is replaced by an equivalent quantity of methyl. One of these bodies a liquid possessing a most offensive odour spontaneously inflammable and explosive in the highest degree corresponds to the liquid phosphoretted hydrogen and appears to occupy in the phosphorus-series the same position which belongs to kakodyl among the arsenic-compounds. It is a colourless somewhat viscid liquid which boils at about 25OOC. Exposed to the slow action of the atmosphere this liquid is converted into a compound which is strongly acid and easily crystallizes.This acid is probably analogous to kaliodylic acid. In addition to this liquid body two solid substances are formed by the action of chloride of inetlipl upon phosphide of calcium. One of these according to M. Paul Th~narcl,corresponds to the solid phosphoretted hydrogen whilst the other which is the prin- cipal product of thc reaction constitutes the hydrochlorate of a very volatile phosphoretted base. From its composition this body may be viemd as ammonia in which the nitrogen is replaced by * Comptes Rendus t. xxi. 1). 1-14 and t. xxv. p. 892. RESEARCHES ON THE PHOSPHORUS-BASES. phosphorus whilst methyl is substituted for the hydrogen. When repeating these experiments in the ethyl-series Paul Thd nard arrived at similar results to which he however only briefly allides.At the time when these experiments were first made the ammo- nia-bases had not been discovered aud the subject presented obstacles so numerous and varied that the researches of this chemist remained unfinished. Nobody will be surprised at this who has made himself acquainted with the difficulty of effecting the above-mentioned reactions and who from his own experience knows the danger which attends the preparation of these com- pounds and the horrible odour which some of them possess. Paul Thgnard’s remarkable researches did not excite at the time of their publication that degree of interest which they really deserved. There were hut few facts known at that period with which his resiilts could naturally be connected ; indeed until after the ammonia-bases were discovered the importance of the experiments on these phosphorus-bodies could scarcely be recog- nized ; then it was that M.Paul Thknard’s investigations attracted that attention to which they were entitled; then it was that the remarkable pzcrallelism of the compounds of phosphorus and nitrogen more and more distinctly cxhibited by these discoveries began to become an object of general interest to chemists. It is now many years since 14. Paul ThGnard abandoned the study of the phosphorus-compounds for the first knowledge of which we are indebted to him. The unfinished state in which these researches remained arid the rich and abundant harvest collected since that period in all the neighbouring fields of science necessitated a revision of the subject.Thc discovery of methyla- mine dimethylamine ad trimethylamine and of the correspond- ing terms in the ethyl- and azmyl-series had shown that the hydro- gen in ammonia may be replaced by binary molecules such as methyl ethyl amgl and phenyl the newly-formed compoirnds retaining the basic character of the original ammonia-molecule ; whilst the production of triethylstibine and triethylarsine had furnished the proof that the total replacement of the hydrogen in the indifferent antimonietted and arsenietted hydrogen exalts the chemical character of these compounds in a most remarkable man- ner the methylated and ethylated lsodies exhibiting basic charm- ters scarcely inferior to those of ammonia itself.It remained therefore to be investigated whether phosphorus which by its chemical tendencies stands between iiitrogen and arsenic would exhibit a similar deportment. It remained to be ascertained in what manner the gradual entrance of binary molccules in the place of the hydrogen in phosphoretted hydrogen mould change the character of the original compound. The discovery of the tetrethylated ammonium-bases had also opened a new fie-d of research in which the corresponding terms of the antimony- and IIOFMANN AND CAHOURS ON THE arsenic-series were rapidly brought to light. It was indeed pos-sible to predict with certainty that an appropriately selected method would lead to the production of the analogous derivatives of phosphoretted hydrogen.The time for resuming the study of the phosphorus-bases had in fact arrived. We have been engaged for a considerable time in the investi- gation of this subject and now beg to offer to the Royal Society in the following pages an account of our experiments. In the first place we have endeavoured to obtain the bases corresponding to phosphoretted hydrogen by a method analogous to that followed by M. Paul The'nard. Recent experience suggested at once the replacement of the gaseous chloride of methyl by the liquid iodide which is so much more convenient for experiment ; and also the substitution for the phosphide of calcium of the compound of phosphorus and sodium obtained by the direct union of the elements.On the application of heat these substances act on one another with great energy producing combustible and detonating compounds so that the experiment is not without danger. Often the product of the operation is lost; and if the reaction has taken place without explosion the separation of the constituents of the very corn-plicated mixture which results can be effected only with the greatest difficulty. We have convinced ourselves that the product of the action of iodide of methyl upon phosphide of sodium consists chiefly of three different substances viz ,of a liquid which probably is Me I? and corresponds to kakodyl; of a second liquid Me P corresponding to trimethylstibine and trimethylaraine ; and lastly of a beautiful crystalline solid body hle,YI which is the analogue in the phos- phorus series of iodide of tetrametliylammonium.We abstain from a minute description of the experiments made in this direction since in the further course of the inquiry we have forsaken this method altogether. Indeed this mode of preparation is very uncertain and the separation of the products formed is attended with almost insurmountable obstacles not to speak of the difficulty of obtaining pure phosphide of sodium fit for the reaction. The question resolved itself into the discovery of a method which would yield us the desired substances conveniently without danger in considerable quantity and in a state of absolute purity. It appeared to us that the action of terchloride of phosphorus on zinc-methyl zinc-ethyl &c.would enable us to attain the desired result. Experiment has fully confirmed this anticipation. Dr. Frankland's remarkable observations on the action of zinc upon iodide of methyl and iodide of ethyl at high temperatures are still fresh in the memory of chemists. Besides the hydro- carbons methyl and ethyl zinc-methyl and zinc-ethyl are formed in this reaction which exhibit the deportment of true organic RESEARCHES ON THE PHOSPHORUS-BASES. metals comparable in the intensity of their combining powers with the most electro-positive elements. In the action of a chlo- ride upon such a compound metal the chlorine was sure to seize upon the zinc and it was extremely probable that together with chloride of zinc methyl- or ethyl-compounds would be formed in definite proportions.In the action of terchloride of phosphorns the formation of a methyl-or ethyl-compound of phosphorus corresponding in composition to the terchloride of phosphorus might be with certainty expected PC1 I-3llleZn = 3ZnC1 + Me,P. These anticipations were in fact fulfilled. The products of these reactions the bases Me,P and E3P which we propose to call respectively trimethylphosphine and triethylphosphine remain nnited with chloride of zinc and simple distillation with an alkali is all that is necessary to liberate them 3ZnC1 Me,P + 6K0 = 3KC1 + 3(KO ZnO) + PMe 3ZnC1 E Y + GKO = 3KC1+ 3(KO ZnO) + PE,. They are obtained in this way as volatile oils with a peculiar and strongly-marked odour and possessing distinct basic properties We found no difficulty in procuring the bodies in question by this method in a state of perfect purity so as to examine their properties with accuracy.From the outline which we are about to give it will be obvious that this group of bodies exhibits the most striking analogies with the ammonia-bases so much so in fact that frequently it will only be necessary to repeat the observations which were published by one of us about eight years ago regarding the methylated and ethylated derivatives of ammonia.* The experiments which we have to communicate refer chiefly to the methyl- and ethyl-compounds; though here and there we have used amyl as material. Since we have preferred working in the ethyl-series we begin with the description of the ethyl-compounds.EXPERIMENTS IN THE ETHYL-SERIES. Action of Terchloride of Phosphorus on Zinc-ethyl. The reaction between these two bodies is very violent and readily gives rise to dangerous explosions if the necessary precau- tions are iieglect.ed. We have generally adopted the following arrangement. A tubulated retort is joined to a receiver which in its turn is connected with a wide glass tube bent at an angle of * Philosophical Transactions 1850,F. 93; 1851 p. 367. EOFWA" AND CAHOURS ON THE about 70° and acts like a second receiver. The angle of this tube is filled with terchloride of phosphorus and the tube is con-nected with a large cylinder which is supplied by a suitable appa- n Apparatus for generating carbonic acid.6. Wabh bottle containing sulphuric acid. c. Reservoir of carbonic acid. d. Bent tube containing terchloride of phos-phorus e. Receiver. f.Retort containing zinc-ethyl. 9. Dropping apparatus filled with terchloride of phosphorus. ratus with dry carbonic acid. As soon as the carbonic acid has expelled the air from the reservoir tube receiver and retort an exit-tube from the reservoir up to that time closed by a caoutchouc cap is opened to let out the carbonic acid the evolution of which is maintained during thc whclc operation. The tubulaturc of the retort is now connected with the copper digcster in which the zinc-ethyl has been prepared ; and as soon as the retort has received a charge of the ethereal solution of zinc-cthyl therc is fixed into the same tubulaturc a little dropping apparatus consistLig of a glass globc aith a tubulature and stopper at the top and termi- nating below in it glass tube iii which a stopcock is fitted.This apparatus is filled mith terchloride of phosphorus and by appro-priately adjusting the stopcock and opening or closing the stopper of the glass globe any desired flow of the fluid can be maintained with the greatest nicety. However slowly thc action may be accomplished md holierer well moreover the retort and receiver may be coolcd by water or ice the action is nelertheless invariably so ~iolent that all the ether and with it a large quantity of the zinc-ethyl passes over iiito the receiver. By the powerful ebullition which periodically ensues a portion of' the vapour is driven even into the bent tube and a considerable loss of zinc-ethyl is incurred unless this tube be filled with terchloride of phosphorus which greedily absorbs every trace of the former compound.This fluid valve ascending and descending in the tube in accordance with the progress of the reaction regulates the function of the apparatus so perfectly that the operation which always takes several hours when once begun continues by itself. Sometimes the absorption is so violent that the terchloride of phosphorus in the tube is sucked back into the receiver but even then no loss is to be feared since the tube is connected with the reservoir filled with carbonic acid. The first drops of terchloride of phosphorus which fall into the solution of zinc-ethyl hiss like water when brought in coiitact with red-hot iron.The action becomes by-and-by less violent and as soon as an evolution of heat is no longer perceptible the operation is tcrminated. There remain in the retort in the receiver in the bent tube and sometimes even in the carbonic acid rescrvoir two liquid layers,-the one a heavy pale straw-coloured thick fluid the other a transparent colourless mobile fluid floating on the former. The heavy fluid a compound of the phosphorus-base with chlo- ride of zinc nearly solidifies on cooling but the viscid transparent mass exhibits no trace of crystallirie structure. The light fluid is a mixture of ether with an excess of the terchloride of phosphorus; after disconnecting the apparatus it is poured off from the viscous fluid and may be used after distillation in a second oper a t’ion.Some ether and terchloride of phosphorus which may still adhere are expelled by gently heating the retort upon a sand bath. In order to liberate the phosphorus-base from its combination with zinc nothing more than a distillation with potassa is required. To prcveiit the destruction of the retort to which the zinc-com- pound adheres with pertinacity and tlie loss of so precious a mate- rial this operation is conveniently performed in the following maimer. Solid hydrate of potassa is placed on the hard resinous cake attached to the bottom of the retort and a slow current of water allowed to flow in by the dropping apparatus after the air in the retort has been carefully displaced by hydrogen the heat evolved during the reaction is quite sufficient to volatilize the base with the vapour of the water ;it may be condensed by an ordinary cooler.The base which is now floating on the water of the distil- late is removed by means of a separating funnel; it is allowed to stand for a day over hydrate of potassa and finally rectified in a current of dry hydrogen gas. Triethy~hos;uhine.-Thus obtained triethylphosphine is a colour- less transparent mobile liquid which strongly refracts light. Thc compound is lighter than water its specific gravity being found to be 0-812at 15O.5 C. ;it is perfectly insoluble in water but soluble in every proportion in alcohol and ether. Its odour is penetrating almost benumbing but still not disagreeable.The intolerable smell which renders it so unpleasant to lyork with these phospho- rus-compounds generally arises from other products which make their appearance in considerable quantitics,. especially in preparing HOPMANN AND CAHOURS ON THE the phosphorus-base by means of phosphide of sodium and iodide of ethyl. In a diluted state the odour of the pure triethylphos- phine has the greatest similarity to that ofthe hyacinth.* Long-continued working with this substaiice causes headache and sleeplessn eas. The boiling-point of the triethylphosphine is 127O.5C. under the barometric pressure of 0.744m The determination was made with an ounce of the pure substance. The distillation of the phosphorus-base must be performed in a stream of dry hydrogen for it attracts oxygen with great energy especially at high tem- peratures.It is impossible to pour the liquid from one vessel into another without its becoming perceptibly warm. The product of oxidation formed in this way becomes evident in the last stage of the distillation. When the larger quantity of the base has dis- tilled over the mercury in the thermometer begins suddenly to rise and before the temperature has become again stationary the neck of the retort is found to be coated with a network of beautiful crystals which are even drawn over into the receiver. These crystals are permanent as long as they are protected from the action of the moist air. After disconnecting the apparatus it is vain to attempt to collect the crystals the most minute quantity of water causing them to liquefy to a heavy oil soluble in water.From these remarks it is obvious that triethylphosphine must be almost always contaminated with a sniall quantity of this sub- stance; in fact a bottle containing the base cannot be opened without its being formed. When the phosphorus-base is brought in contact with oxygen vapours are immediately formed ; the liquid frequently becomes so hot that it inflames and the body is burnt with evolution of dense white fumes of phosphoric acid. If a strip of paper moistened with triethylphosphine be introduced into a test-tube containing oxygen and immersed in hot water the vapour of the phosphorus-base produces with the oxygen an explo-sive mixture which detonates after a few moments with consider- able violence.With atmospheric air a similar detonating mixture is formed which explodes at comparatively low temperatures. To avoid serious accidents the phosphorus-base should always be dis- * There is nothing new in the fact that the odour of a substance may be consider- ably changed by dilution. Several years ago when occupied in the preparation of different ethers which have found numerous applications in perfumery I had frequent opportunities of observing how the desired aroma which was absent in the pure sub-stance was brought out by dilution with alcohol. The hyacinth smell of the dilute phosphorus-base is so characteristic that one morning I found in my laboratory a large basket filled with hyacinths the present of a lady friend of mine who interested in my labours had a strong impression that triethylphosphine must be present in the hyacinth.In the interest of science the entire floral adornment of the garden had been unmercifully sacrificed ! It would have been ungrateful not to distil them but I regret to say that the anticipation of the amiable donor who wished to enrich me with so interesting a discovery proved unfounded. The hyacinth does not contain any phosphorus-base.-A. W. H. RESEARCI-IES ON THE PHOSPHORUS-BASES. tilled in an atmosphere of hydrogen. When poured into a flask filled with chlorine gas every drop of triethylphosphine is inflamed with disengagement of pentachloride of phosphorus and hydrochlo- ric acid and separation of carbon.The phosphorus-base unites with bromine and iodine evolving considerable heat which may give rise to inflammation; but if the action be moderated crystal- line compounds are produced. In cyanogen gas the phosphorus- base is converted into a brown resinous mass. If a piece of sul-phur be thrown into a test-tube containing triethylphosphine it becomes so hot as to fuse the sulphur which then floats on the liquid base in the form of globules as sodium does on water and at last entirely disappears. The clear liquid thus obtained solidifies on cooling to a magnificent crystalline mass. The experiment must be made with caution since the vapour of the phosphorus- compound which rises during the reaction generally explodes on coming in contact with the air contained in the vessel.Selenium gives rise to similar but less powerful phenomena. Although triethylphosphine in its relations to other bodies powessea all the characters of a well-defined base it does not exhibit an alkaline reaction. When freshly prepared it is without action on vegetable colours but when exposed only for a few moments to the influence of the air it begins to show a con-stantly increasing acid reaction. Triethylphosphine unites with acids slowly but with considerable evolution of heat ; with con- centrated acid the temperature frequently rises to such a degree as to give rise to inflammation of the liquid. Most of its salts are crystalline compounds but are very soluble and deliquescent.The composition of triethylphosphine" is represented by the formula El E Triethylphosphine forms crystalline compounds with the hydro- gen-acids of chlorine bromine and iodine with sulphuric and nitric acids; but all these salts which can be obtained in the dry state only by the aid of the exsiccator are but little suitable for analysis. The solution in hydrochloric acid affords a crystalline platinum-salt which is insoluble in cold water in alcohol and ether but which on account of the facility with which it decom-poses at 100' C. must be dried in the exsiccator. In the water- bath it fuses and is altogether decomposed. The determination of the platinum in the phosphorus-compounds presents considerable * The analytical details are giveu in the original paper published in the Philo- sophical Transactions for 1857,p.575. HOli’MANN AND CAXIOURS ON THE difficulties. The platinum in these substances cannot be deter- mined in the ordinary way by simple. ignition because a consider-able quantity of platinum is carried off with the phosphorus- vapour however slowly and carefully the process may be carried out. We unfortunately did not find this out until a great number of unsuc- cessful analyscs had been made. By heating with a considerable excess of carbonate of sodium in a porcelain crucible on a sand-bath the temperature of which is gradually raised the determina- tion succeeds without difficulty. After removal of the portion soluble in water the platinum-residue which is always contami- nated with silicic acid is dissolved in iiitrohydrochlloric acid the solution evaporated to dryness and- the residue again dissolved in acid thc careful evaporation of this solution furnishes a perfectly accurate result.This metliocl is somewhat tedious but there is some compensatiou for this iiicreased coniplexity by the simulta- neous determination of the chlorine. The analysis of the platinum-salt of tiaiethylphosphiiie has led to the formula Cl2HI5P HC1 PtCI,=E,P HC1 PtC1,. The analyses of the base itself and of the platinum-salt sufficiently fix the composition of triethylphosphine. This compound is in fact triethylamine in which the nitrogen is replaced by an equivs-lent quantity of phosphorus.The perfect analogy with triefhyla- mine is also shown by the deportment of the phospliorus-base with the iodides of ethyl methyl and amyl. Triethylphospliine com-bines with these substances forming well-crystallized and highly characteristic salts which may be regarded as iodide of amnio-nium in which the nitrogen is replaced by phosphorus and the hydrogen by the radicals of the alcohols. Iodide of TetretliyTp~~os~honiuln.-Onmixing triethylphosphine with iodide of ethyl a violent action ensues after a few moments; the liquid effervesces with almost explosive violence and then solidifies to a white crystalline mass. If instead of the pure base an ethereal solution be employed the crystals are formed more slowly. This new compound is extremely soluble in water less so in alcohol and insoluble in ether.The aqueous solution crystal- lizes on addition of potassa-solution in which this compound like the iodides of tetramethylammonium and tetrethylammonium is but slightly soluble. From the alcoholic solution the salt falls on addition of ether as a crystalline powder. If ether be added to a cold alcoholic solution as long as thc precipitate first produced is dissolved by boiling well-formed crystals of the iodide are deposited .on cooling. The mode of forination and the analysis leave no doubt respecting RESEABCHES ON THE PHOSPHORUS-BASES. the nature of these crystals. They contain the elements of 1 equiv. of triethylphosphine and 1 equiv. of iodide of ethyl. -C,,H,,P + C,H,I = C16H20PI.+ + Triethyl-Iodide of New compound. phosphine. ethyl. The new body corresponds to iodide of tetrethyl-ammonium. Notwithstanding the transparency of the constitution of these compounds we feel some embarrassment in fixing their nomen- clature. We propose to designate the hypothetical compound of one equivalent of phosphorus and four equivalents of ethyl by the name ‘‘Tetrethylphosphonium.” This term is long but it leaves no doubt regarding the composition of the body and marks at the same time its analogy with tetrethylammonium. The iodine- compound is accordingly the iodide of tetrethylphosphonium. Hydrated Oxide of Tetrethy~hosphonium.-The separation of the iodine from the before-mentioned compound presents no diffi-culties. Oxide of silver removes this element even at the common temperature.A strongly alkaline solution is obtained which retains a small quantity of silver in solution. This liquid which is almost without odour and has a bitter and phosphoric taste dries up when placed over sulphurjc acid into a crystalline, extremely deliquescent mass the silver separating at the same time in the form of a black powder or as a brilliant metallic mirror. The mass when redissolved in water furnishes a colour- less liquid free from silver but generally containing some carbonic acid. The avidity with which the oxide of tetrethylphosphonium attracts both water and carbonic acid has prevented us from ana- lysing this body but its formatian the composition of the corre- sponding iodide and the analyses of a platinum-and gold-salt hereafter to be mentioned sufficiently warrant the formula In its deportment with other substances the body in question resembles the oxide of tetrethylammonium ; we refer therefore to the detailed description which one of us has given of this com- pound in a former memoir.” The solution of the oxide of tetre-thylphosphonium shows in fact all the reactions of a solution of * Journal of the Chemical Society vol.4 p. 304. VOL. xr. F HOFMANN AND CAHOURS' potassa; the precipitates such as alumina and protoxide of zinc dissolve however less readily in excess of the phosphorus-compound. The action of heat upon this body gives rise to a peculiar transformation to which we shall return hereafter.Tetrethylphosphonium produces crystallizable salts with hydro- chloric nitric and sulphuric acids. All these compounds exhi bit the deliquescent character of the oxide. Like the latter they are also soluble in alcohol; in ether they are for the most part insoluble. The hydrochloric solution furnishes with bichloride of platinum and terchloride of gold difficultly soluble precipitates which are well adapted for analysis. Chloride of Tetrethy@hosphoniumund Bichloride of Plutinum-The pale orange-yellow precipitate which falls on addition of bichloride of platinum to a moderately dilate solution of the chloride dissolves with difficulty but without decomposition in boiling water; it is insoluble in alcohol and in ether. It can be dried at 100' C.Formula C16H2,PC1 PtCl =7PCl,PtCl,. E Chloride of TetrethyJphosphoniurn and Terchloride of Gold-The! arystalline precipitate obtained by mixing the two solutions sepa-mtes from boiling water in brilliant golden-yellow needles. ACTION OF HEAT UPON OXIDE OF TETRETHYLPHOSPHONIUM. The change which oxide of tetrethylammonium undergoes by the action of heat is well known ;this body splits into olefiant gas water and triethylnmine E,NO HO = C,H + 2H0 + E,N. We expected an analogous transformation of oxide of tetrethylphos-phonium but experiment has proved that this body suffers a different decomposition. On submitting freshly-prepared oxide of tetrethylphosphoniurn to distillation water only passes over in the first instance; but as soon as the solution has attained a certain state of concentration it suddenly effervesces with evolution of an inflammable gas which may be collected over water.This gas contains carbon and hydrogen but no phosphoms; it may be left RESEARCEES ON THE PEOBPHORUS-BABES. in contact with bromine-water without experiencing the slightest absorption. This experiment shows that the gas cannot contain any ethylene and with almost the same certainty we may infer the absence in it of all the hydrocarbons of the formula.C,H,. The evolution of gas ceases long before the whole amount of' the liquid contained in the retort has distilled over. On the contrary it is observed that immediately after the evolution of gas has ceased the distillation nearly stops and commences again only when the temperature has reached 200'; a viscid nearly inodorous liquid now distils over the temperature slowly rising until at about 240' a constant boiling-point is attained what now distils gene- rally solidifies to a radiated crystalline mass in the neck of the retort.On fusing this mass with a spirit-lamp and collecting the liquid in a receiver it frequently resolidifies instantaneonsly on cooling; often however it remains liquid for months. This body is extremely deliquescent a crystal exposed to the air only for a few seconds liquefies entirely. It is soluble in water in every pro-portion also in alcohol less so in ether. The aqueous solution is precipitated by potassa; the dissolved body separates in this case in colourless oily drops which remain liquid even after much con- centration and rapidly dissolve again on diluting the potassa solu-tion with a comparatively small quantity of water.Acids dissolve the oil likewise vith facility. It is obvious at a glance that the body in question is identical with the product formed by the action of air upon triethylphos- phine. A careful comparison of the properties of the two sub-stances places their ideutity beyond any doubt. It is moreover easily proved that the body is a product of oxidation. On boiling triethylphosphine with moderately strong nitric acid and adding potassa to the highly concentrated liquid the characteristic oily drops are immediately separated and disappear again upon addi- tion of water. At the common temperature oxide of mercury is without action upon triethylphosphine ;but on gently warming the mixture a considerable evolution of heat takes place metallic mer- cury is separated and an oily substance produced which has all the characters of the new compound and often sublimes in radiated crystals coating the colder part of the vessel.With oxide of silver exactly the same phenomena are observed. On the other hand the oily body when submitted to the action of potassium, instantaneously reproduces triethylphosphine. It is difficult to obtain this body in a state fit for analysis. It is not affected by solid hydrate of potassa but on distilling the two substances together the distillate is nevertheless found to contain a certain amount of moisture the hydrate of potassa losing a cer-tain quantity of water at the temperature of distillation.If the crystalline mass be separated from the potasss before distillation it attracts so much water during manipulation tliat even now it F% HOPMAINN AND CAHOURS’ becomes but irnparfcctly crystalline after distiliation. Distillation with anhydrous phosphoric acid ftirnishes the compound perfectly di-y and solid ; unfortunately however a portion of the substance is thus decomposed with separation of free phosphorus which con- taminates tlie distillate. Nor have we succeeded in uniting this substance to crystalline combinations ; nitrate of silver bichloride of platinum and several other reagents were tried in vain. It is obyious that the preparation of this body in a state of purity is attended with uniisual difficulties.These difficulties might cer- tainly have been surmounted but we believe that the deportment of triethylphosphine with sulphur and selenium which will be more minutely describ2d hereafter enables us to infer retrospectitely the composition of the oxide with a degree of certainty scarcely inferior to that furnished by analysis itself. The examination of well-defincd sulphur- and selenium- compounds of the composition xmwctive1.v “ Cl2FIl5PS2 =E,YS and C,,H,,PSe =E,PSe, sufficiently proves that the body in question is the corresponding oxide that it is in fact a combination of triethylphosphine with 2 equivalents of oxygen C,,€I,,PO,= 13,PO ; an inference which is moreover snpported by the existence of analogous and similarly formed combinations in the antimony- and arsenic-serics viz.C,,H,,SbO,=E,SbO, and C1,Hl5AsO2= E,As02. The formation of such a binoxide by the distillation of the hydrated oxide of tetrethylphosphonium is readily intelligible if we assume that the hydrocarbon simultaneously disengaged con- sists of hydride of ethyl an assumption which is in accordance with the general characters of this gas. E,PO HO = E,PO + EH Hydrated oxide of Binoxide of Hydride of tetrethylphosphonium. triethylphosphine. ethyl. We should have liked to establish this cquation by some analy- tical numbers but after some fruitless trials to prepare the sub-stance in a state of purity me were obliged to desist from the attempt.Even the preparation of a considerable quantity of oxide of tetrethylphosphonium is a long laborious and expensive opera- tion ; hut to these nunierous impediments a further difficulty is added which at tlie first glance appeared altogetlier inexplicable. Under certain conditions the distillation of oxide of tetrethylphos- phonium furnishes either no inflammable gas at all or only traces ; at the same time the formation of the crystalline binoxide either RESEARCHES ON THE PNOSPHOKUS-BASES. 69 entirely ceases or takes place only in very minute quantities. We have convinced ourselves that this invariably occurs when the alkaline solution by exposure to the air has attracted a consider- able quantity of carbonic acid.Instead of hydride of ethyl and binoxide of triethylphosphine the phosphorus-base itself is obtained in this case together with another liquid body which contains no phosphorus. By dissolving the distillate in ether fixing the triethylphosphine by sulphur and then evaporating tlie ether an inflammable aromatic liquid remains which floats on water. We had not more than a few drops of this oil at our disposal which prccluded the idea of an analysis but we have no doubt that this liquid is carbonate of ethyl. E,Y,CO = E,P + ECO,. Carbonate of Triethyl-Carbonatc tetrethylphosphonium. phosphine. of ethyl. Chloride Bromide and Iodide of Triet~~y~ho,~~~hine.-13inoxide of triethylphosphine when treated with hydrochloric hydrobromic and hydriodic acids is converted into the corresponding chloride bromide and iodide which closely resemble the oxide in their general properties.They are liquids which gradually solidify in the exsiccator; the crystals fuse at 100' and begin to volatilize although their boiling-point is very high. Thc compounds of triethylphosphine with chlorine bromine and iodine may also be obtained by the action of these elements in aqueous or alcoholic solutions upon the phosphorus-base itself. Both methods how- ever fnrnish proclucts which are difficult to purify. These compounds as well as the saline compoiinds which tlic oxide of triethylphosphine produces with sulphuric and nitric acids and which in the exsiccator gradually solidify into semi-crystalline masses have.but slightly occupied our attention because the for-mation of beautiful sulphur- and seleniuiri-compor~ndls enabled us to gain a sufficiently precise idea regarding the chemical characters of these substances in geiieral. Bisulphide of Tr..iethyl23hos~fzine.-Tlle Ten3arkable pheiiom ena which attend the combination of trietliylphospliine with sulphur have been already described. The compound is likewise olltained hy distilling triethylphosphine with cinnabar which in this reactiou ia reduced to subsulphide or to metallic mercury. Treatment of the oxide of triethylphosphine with sulpliuretted hydrogen or with sulpliide of amrnoiiium does not furnish the compound. The best mode of preparing this beautiful body is the following Illlowers of sulpliur are gradually introduced into a dilate solution of the phosphorus-base in ether ; the liquid efl'crvesccs iipn each addition and tlie sulphur disappears.As soon as sulphur remain- ing undissolved inr?icates the completion of the rcaction the ether 7S HOFMANN AND CAHOURS’ is volatilized and the residuary mixture of free sulphur and bisul- phide of triethylphosphine separated by boiling water. On cool- ing the liquid deposits the compound iu. crystals of perfect purity. This sulphur-compound is one of the finest products with which we have become acquainted in the course of our inquiries. Its crystal-lizing power is such that by slowly cooling the solution most beautiful crystals may be obtained even in a test-tube the liquid column being traversed by an aggregate of thin vertical needles of five or six inches in length.The difference of the solubility of the compound in cold and boiling water is very great; indeed but a minute quantity remains in solution at the common tempera- ture. On adding an alkali to the cold solution the mixture becomes turbid and deposits after a few moments small crystals. The sulphur-compound in this respect resembles the corresponding oxide which is likewise less soluble in alkalies than in pure water. This phenomenon is most strikingly observed by adding potassa to a boiling saturated aqueous solution of the bisulphide ; it instan- taneously separates in clear oily drops which rapidly solidify into spherical aggregates of crystals as the liquid cools.The compound is even more readily soluble in alcohol and ether and also crystal- lizes from these liquids but less beautifully. The solubility in bisulphide of carbon is almost unlimited; from this solvent it crystallizes imperfectly. The fusing-point of the bisulphide of triethylphosphine is 94O C. it resolidifies at 88’ C When heated beyond 100’ C. the bisulphide is volatilized with diffusion of a white vapour of a disagreeable sulphur-odour which is but slightly perceptible at the common temperature When heated with a quantity of water insufficient for its solution the sulphur-compound rises to tlie surface as a clear transparent oil which is copiously volatilized with the vapour of water. The solution of the bisulphide is without action on vegetable colours.The compound nevertheless appears to possess faintly basic properties. It dissolves more readily in hydrochloric acid especially when Concentrated than in water and the solution fur-nishes with bichloride of platinum a yellow precipitate which however rapidly cakes into a resinous mass giving indications of decomposition by the separation of bisulphide of platinum so that it was not adapted for analysis. The sulphur-compound also dis- solves in dilute sulphurio and nitric acids ; concentrated nitric acid decomposes it; the fuming acid gives rise to a sort of detonation. The aqueous solution of the bisulphide is not affected by acetate of lead nitrate of silver or protoxide of mercury even at the boiling temperature ; the alcoholic solution on the other hand is instan- taneouPly decomposed with separation of the sulphidc of lead silver or mercury.The liquid filtered off from the precipitates now contains the oxide of triethylphosphine eitber free or in tlie form of acetate REBEARCHES ON THE PHOSPHOBUS-BASES or nitrate and may be readily separated by the addition of an alkali to the solution. The action of potassium upon this compound in- stantaneously reproduces the phosphorus-base. The bisulphide of triethylphosphine has the composition C, H,,PS,=E PS,. The formation of the bisulphide takes place with such facility and the properties of the compound are so characteristic that we have frequently used flowers of sulphur as a reagent for triethyl-phosphine.BiseZenide of Triethylphosphine.-In the action of selenium upon triethylphosphine the phenomena described in the preceding para- graphs are repeated. The reaction however as might have been expected is less powerful. The selenium-compound crystallizes from water with the same facility as the sulphur-compound but the solution is apt to undergo partial decomposition when exposed to the atmosphere. Even the dry crystals are slowly reddened in the air. The fusing point of the selenide is llZo C.; it is easily volatilized undergoing partial decomposition. It contains C ,K ,PS e2=E,P Se2. In order to give more completely the history of the phosphorus-bases we have also examined the compounds which are formed by the action of the iodides of methyl and amyl upon triethylphosc phine; but since the products of these reactions resemble in every respect the corresponding ethyl-compounds we have only to men-tion the analytical results.Iodide of Methylt9.iethy~hos~honium.-In treating triethylphos- phine with iodide of methyl all the phenomenamentioned in the case of the analogous experiment with iodide of ethyl are repeated. The action is still more violent and rapid and if no ether be added a portion of the productIis readily lost by the explosive effervescence of the liquid The crystals thus obtained contain C14H18PI=(MeEJPI. On treating the solution of this compoiind which essentially resembles the simple ethyl-compound with oxide of silver a strongly alkaline solution of oxide of methyltriet h y lph osphoniurr is obtained.The solution when saturated with hydrochloric acid and mixed with bichloride of platinum furnishes a beautiful orange- yellow platinum -salt cry stallizing in well-defined cubes truncated by the planes of the octahedron. This salt which is insoluble in alcohol and ether may be recrystallized from boiling water without decomposition;it contains C,,H,,PCl PtC1,= (MeE,)PCl PtC1,. Iodide of TriethyZamylphosphonium.-Iodide of an@ acts but HOFMANN AND CAHOURS' slowly on the phosphorus-base. From a mixture of the two sub- stances in ether beautiful crystals are deposited after a few days which may be purified by solutionin alcohol and precipitation by ether ; they contain C,,HQ6PI = (E,Ayl)PI. Treatment of this compound with oxide 9f silver furnishes the free oxide of triethylamylphosphonium with all the properties cha- racteristic of the class.The corresponding chloride deposits on addition of biehloride of platinum a beautiful platinum-salt crys- tallizing in prisms with flat terminal planes. It is insoluble in alcohol and ether but rather soluble in water. The platinum-salt has the composition C,H,GPCI PtCI = (E,Ayl)PCl PtCl,. ACTlON OF HEAT UPON THE HYDRATED OXIDE OF TRIETHYLAMYL-PHOSPHONIUM. On heating this oxide a small quantity of an iiiflammable gas is evolved a liquid being formed at the same time which boils at about 283' C. and obviously corresponds to the binoxide of trie- thylphosphine. Two distinct changes may occur in this case.Since the oxide contains several radicals it is possible that either ethyl OF amyl may be eliminated in this decomposition and tho liquid simultaneously generated must therefore contain either (E,Ayl) PO, or E PO,. The higher boiling-point of the compound and the deportment of the corresponding nitrogen-term (the oxide of triethylamylarn-monium) which on distillation furnishes diethylamylamine toge-ther with water and olefiant gas are in favor of the first assump-tion. Accordingly the inflammable gas would also in this case be hydride of ethyl and the transformation of the oxide of triethyvl-amylphosphonium under the influence of heat wouid be represented by the equation (E,Ayl)PO HO = (E,Ayl)PO + EH- F Y l phosphonium. - Binoxide of diethyl-amylphosphine.Hgdrideof ethyl. Experimentally the question remains undecided. EXPERIIIENTS IN THE METHYL-SERTES. The results recorded in the preceding sections afford a tolerably complete view of the phosphorus-bases. We may therefore be brief ftESEARCHES ON THE PHOSPHORUS-EBSES. in describing the experiments which we have made with the methyl-compounds. TrimethyZ~hosphine.-This remarkable body is obtained by the same process which we have minutely described for the preparation of the corresponding ethyl-base. Zinc-methyl and terchloride of phosphorus furnish the compound of chloride of zinc and trirne- thylphosphine from which the base may be expelled by the action of' potassa. All the precautions wlzich have been mentioned as ne-cessary in the preparation of the ethyl-base are required in a higher degree for the methylated body.Since zinc-metliyl attracts oxy- gen even with greater avidity than zinc-ethyl the current of carbonic acid must be continuously maintained for a long period. The intensity with which zinc-metlig 1 decornposes terchloride of phosphorus is not inferior to the violerit reaction between caustic baryta arid anhydrous sulphuric acid. The mixing cam ot there-fore be too slowly effected. In expelling trimethylpliosyhine from its zinc-compound refrigeration by ice is absolutely necessary since this body is far more volatile than the ethyl-base. The distillation must be made in hydrogen gas and the current of gas must rnore- over flow very slowly otherwise however perfect and careful may be the arrangements for cooling a considerable quantity of the body will be carried off' in the hydrogen and be lost not to speak of the difk'usion of the almost intolerable odor of the methyl-base in the atmosphere of the laboratory.Trimethylphosphine is a colourless transparent very mobile liquid of an indescribable odour powerfully refracting light lighter than water in which menstruum it is insoluble. The boiling-point of the liquid lies between 40' and 42' C. which agrees with Paul Th 6n a rd's observations. Trimethylph osphine has even a more powerful attraction for oxygen than the corresponding ethyl-base. In contact with the air it fumcs and is apt to be inflamed. On distilling even the freshly prepared methyl-base the rreck of the retort becomes coated in the last stage of the operation with a net- work of beautiful crystals perfectly similar to those which are ob- served with the ethyl-base.These crystals may be readilr obtained in larger quantity by exposing the methyl-base to a slow current of dry atmospheric air. It is scarcely necessary to mention that these crystals are the Binoxide of trimethylphosphine. In its deportment with chlorine bromine iodine sulphur and selenium and finally .with the acids the methyl-base exzctly imitates the ethplated body. The reactions are however more rapid and energetic. We have been satisfied to identify trimethylphosphine prepared by means of zinc-methyl by the analysis of a platinum-salt. Hydrochlorate of Trimethyl]Jhosphine and Bichloride of Platinum.-The solution of the methyl-base in hydrochloric acid furnishes with bichloAe of pl:itiiium an orazlge yellow iiiclistinctly crystal- HOPMA” AND CAHOUR6’ line precipitate which like the corresponding ethyl-compound is readily decomposed by exposure to looo C. For analysis it waa dried in the exsiccator over sulphuric acid It contains C6H,P HC1 PtCI = Me,P HCl PtC1,. Iodide of Tetramet~y~ho~honium.-The iodide is a white crys- talline mass obtained by the action of iodide of‘ methyl upon an ethereal solution of triethylphosphine. This compound which may be readily recrystallized from alcohol is the finest product of the series. Freshly prepared it exhibits the silvery lustre of sublimed naphthalin.In contact with the atmosphere it assumes a slightly reddish colour. The composition of this compound is represented by the formula C,H,,PI = M,PI. On treating the solution of the iodide with oxide of silver a very caustic solution of the oxide is obtained. Chloride of Tetramethy~ohosphoniumand Bichloride of Platinum. -The solution of this oxide mixed with hydrochloric acid and bi- chloride of platinum furnishes a platinum-salt which is insoluble in alcohol and ether but crystallizes from water in beautiful octa- hedra. It contains C,H,,PCl PtC1 Me,PCl PtCl,. =3 Chloride of Tetramethy~hos~honium and Terchloride of Gold.-The method of preparation and the properties of the gold-salt of chloride of tetrnmethylphosphonium are perfectly similar to those of the corresponding ethyl-body.Formula CsH,,PCI AuCl = Me,PCl AuC1,. ACTION OF HEAT UPON THE HYDRrZTED OXIDE OF TETBAME-THYLPH0S 1°C) NT UM. Binoxide of Trimethy~hosphine.-Precisely similar phenomena as in the ethyl-series formation of binoxide of trimethylphosphine and hydride of methyl (marsh-gas). -ME,PO,HO = Me,HPO + MeH L-w L,-J Hydrated oxide of Binoxide of tri-Hydride of methyl tetramethylphosphonium. rnethylphosphine. (marsh gas) The direct formation of the binoxide by the action af oxygen upon trimethylphosphine has been already mentioned. Bisubhide and Biselenide of Trimethylphosphine.-These bodies likewise resemble the corresponding members of the ethyl-series ; they are however more soluble and more volatile.The sulphur- RESEARCHES ON THE PHOSPHORUS-BASES. compound crystallizes from a highly concentrated aqueous solution in masses of well-formed four-sided prisms which fuse at 105O C. The selenium-compound crystallizes exactly like the ethyl-body ; its fusing-point is 84OC. In contact with the air this compound blackens with separation of selenium. In this decomposition the characteristic odour of mesitilene is very perceptibly envolved. Even without an analysis me may assign to these compounds the formulz C,H,PS = Me,PS and C6H,PSe = Me,PSe,. In conclusion the action of the iodides of ethyl and my1 upon trimethylphosphine may be briefly mentioned. Iodide of Tri3nethylethylpho~phonium.-This substance is rapidly formed by the action of iodide of ethyl upon the ethereal solution of the methyl-base.The compound which crystallizes perfectly well from boiling alcohol contains C,,H,,PI = (Me,E)PX. Chloride of TrimethylethyIpho~phoni~cm and Bichhride of Plati-num.-By treating the iodide with oxide of silver the caustic oxide is obtained which gives with hydrochloric acid and bichloride of platinum a yellow platinum-salt insoluble in alcohol. and ether but rather soluble in water. From the boiling solutbn it is depo-sited in magnificent octahedra. Formula CloHl,PC1l PtCI = (Me,E)Cl PtCl Iodide of Trirnethylamylphospkonium.-The ethereal solution of tlie constituents slowly deposits this compound. It is extremely soluble in water and hence if the ethereal solution of the iodide of ethyl contain the most minute trace of water the salt separates in the form of a syrup which only gradually solidifies.It crystallizes in needles although with difficulty from absolute alcohol. Its composition is C16H,,PI = (Me,Ayl) PI. Chloride of Trimethylamylphosphonium and Bichlori tie of Plati-num. This oxide liberated from the iodide by means of oxide of silver furnishes with hydrochloric acid and bichloride of platinum a very soluble platinum-salt which crystalliEes from boiling water in splendid needles aggregated in spherules. Formula Cl6Hg0PC1 PtC1 = (Me,Ayl) PC1 PtC4. HOFMAIIN AND CANOURS’ The analysis of this platinum-salt concludes the experimental part of our inquiry ;for clearness and comparison we subjoin the following synapsis of the compounds wliich we have investigated.a. ME THYL-S E1% I ES. Trimethylphosphine ......Me,P. Platino-chloride of trimethylphosphine ..Me,P HC1 PtCI,. Binoxide of trimethylphosphine ... .Mt$?O,. Bisulphide of trimethylphosphine ...Me,PS,. Biselenide of trimethylphosphine . .Me,PSe,. Iodide of tetramethylphosphonium . ..MeiPI. Platino-chloride of tetramethylphosphonium .Me,PCl PtCl,. Auro-chloride of tetramethylphosphonium ..bfe4PCl AuC1 Iodide of trimethylethylphosphonium ..(Me,E)PI. Platino-chloride of trimethylethylphosphonium .(Me,E)PCl PtCl,. Iodide of trimethylamylphosphonium . ..(Me,Ayi)PI. Platino-chloride of trimethylamylphosphonium .(bIe3Ayl)PC1,PtCI-. p. ETHYL-SERIES. Triethylphosphine ......ESP.Platino-chloride of triethylphosphine ...E,P,RCl PtClP. Binoxide of triethylphosphine ....E,POp Bisulphide of triethylphosphine ....E,PS,. Biselenide of triethylphosphine . ..&PSe,. Iodide of tetrethylphosphonium ....EJPI. PIatino-chloride of tetrethylphosphonium . ,E4PG1 PtCI,. Auro-chloride of tetrethglphosphonium . .E4PC1 AliCI,. Iodide of methyltriethylphosphoninm ..(MeE3)PI. Platino-chloride of me thy ltriethylphosphonium ,(MeE3)PCl I’tCl? Iodide of triethylamylphosphonium ...(A71 E,)PI. Platino-chloride of triethylamylphosyhonium .(Ayl E3)PCI PtC1,. Oil glancing once more over the phosphorus-compounds described in the preceding memoir a comparison of these substances with the corresponding terms of the nitrogen- arsenic- and antimony- series is unavoidably forced upon us.Whether we consider the composition or whether me review the properties of these groups the most striking analogies indeed an almost perfect parallelism cannot be mistaken; the same forrniiliE the same mode of com-bination the same decompositions. This analogy is particularly manifest in the compounds helong- ing to the ammonium-type. In these remarkable bodies nitrogen phosphorus arsenic and antimony appear to play absolutely the same part. It is morc especially in the oxides of these compound metals that analogy of composition induces a perfect identity in properties arid indeed of very salietit properties which mzy be traced in almost every direction. If we were satisfied with tlie study of the reactions of these bodies we should never suspect in RESEARCHES ON THE PHOSPHORUS-BASES compounds exhibiting such a close similarity of properties the presence of elements so dissimilar as nitrogen phosphorus arsenic and antimony ; they might moreover be confounded VI ith potassa and soda by which they are scarcely surpassed in*alkaline power.Only the deportment of the hydrated oxides uu&r the influence of heat distinguishes the derivatives of nitrogen from the corre- sponding terms of the phosphorus- arsenic- and antimony-series. If we regard on the other hand the compounds belonging to the ammonia-type me observe that the electro-positive character of the substances gradually rises in intensity from the nitrogen- to the antimony-compounds.Thus trimethylamine and triethylamine are not capable of uniting with oxygen chlorine bromine and iodine ; a power which the corresponding terms of the phosphorus- arsenic- and anti- mony-series possess in a high degree. Triethylarnine unites with the acids producing cornpounds of the for mu1 it E,N HCl E,N HSO E,N HNO,. The corresponding compounds in the arsenic- and antimony-series do not exist ; at all events chemists have not yet succeeded in preparing them. Triethylarsine and triethylstibine only coin- bine directly with oxygen chlorine sulphur &c. pducing saline bodies which have the composition respectively -E,AsO . . . . E3Sb0 E,AsCl . . . . E3SbCl E,AsS . . . . E,SbS,. In the phosphorus-series lastly the two classes are repre-sented.Triethylpliosphine not only forms compounds analogous to the salts of triethylamine but also the terms corresponding to the binoxides of triethylarsine and triethylstibine MTe have in the first place the terms ESP,HCI E3P HSO E3P HNO, and in the second place compounds of the formulae E3PO2 E3PC1 E,PS,. The phosphorus-compounds accordingly hoid a position inter- mediate between the nitrogen-compounds on the one hand and RESEARCHES ON TEE PHOSPHORUB-BASES. the arsenic- and antimony-series on the other. It cannot howd ever be denied that the phosphorus-compounds stand closer to the arsenic- and antimony-series than to the nitrogen -group. This cannot surprise us when we consider the close analogies which phosphorhs and arsenic present in many other directions.Both phosphorus and arsenic form well-characterized polybasic acids; the acids of antimony are not yet sufficiently investigated but the acids of nitrogen which are better examined are all found to be essentially monobasic. The equivalent numbers too of phos-phorus arsenic and antimony present a remarkable connection the difference between those of phosphorus and arsenic and those of arsenic and antimony being virtually the same- Phosphorus . . . difference . . . 44, Arsenic . . . . . 75 "'2 . . . 45, Antimony . . . . 120J&difference whilst the equivalent of nitrogen stands altogether apart from the rest. The same relative position of the elements nitrogen phosphorus arsenic and antimony may also be traced in their hydrides H,N H3P H3As W,Sb.Ammonia is a powerful alkali ;-phosplzoretted hydrogen only unites with hydrobrornic and hydriodic acids whilst in arsenietted and antimonietted hydrogen the power of combining with acids has altogether disappeared. In these hydrogen-compounds the gradation of properties is indeed much more marked than in their trimethylated and triethylated derivatives. On comparing the terminal points of the series ammonia and antimonietted hydrogen we cannot fail to be struck by the dissimilarity of properties which at the first glance appears to limit the analogy of the two com- pounds to a mere parallelism of composition. In the methylated and ethylated derivatives of these compounds the intensity of the chemical tendencies in general is so much raised that the gradation is no longer perceptible to the same extent.We cannot conclude thisr memoir without thankfully acknow- ledging the able and untiring assistance we have received during this lengthened inquiry from Dr. A. Leibiua in the analyses and from Messrs. W. H. Perkin and C. Hoffmann in the prepara- tion of the numerous compounds which had to be investigated. On a New Series of 8rgani0 Aeids containing NWogen. By E. Frankland Ph.D. F.R.S. Lecturer on Chemistry at St. Barthelomew’s Hosyita€.* (Read before the Royal Society June 19 1866.) ABSTRACT. INthe progress made by Organic Chemistry during the past fifteen years no generalization has perhaps contributed so extensively to the development of this branch of the science as the doctrine of substitution.The value of this doctrine becomes even still more apparent when it is remembered that chemists have until very recently possessed adequate means for following out its sugges-tions in one direction only. The peculiar habits of chlorine render the substitution of an electro-positive constituent by this element generally a work of little or no difficulty and even the like substitution of other electro-negative for electro-positive elements in organic bodies presents no insurmountable obstacles. But the inverse process has hitherto been successfully accomd plished only in comparatively few cases owing to the want of a body capable like chlorine of effecting such a replacement with facility.This want is now supplied in zincmethyl and its homo- lopes; bodies which on account of their intense affinities and peculiar behaviour possess in an eminent degree the property of removing electro-negative constituents and replacing them by methyl ethyl &c. The action of zincmethyl upon water attended as it is by the substitution of methyl for oxygen C H Zn C,H,,H %o)={zno may be regarded as the type of these reactions which open up a most extensive and perfectly new field of research from the culti- vation of which important discoveries cannot fail to spring. Amongst the reactions of this nature which promise most interest- ing results are those with the chlorine and oxygen substitution products derived from the ethers and organic acids which might lead to the higher members of each homologous series being pro- duced from the lower ones if not to the building up of some of those series from their inorganic types ; a discovery which cannot now remain long in abeyance.? Instead of immediately pursuing this line of investigation however I determined in the first place to confine my attention to the action of these organo-zinc bodies upon inorganic compounds.In a former memoir$ I endeavoured to give a general view of * Phil. Trans. 1857 59. t This discovery has since been made by Mr. WankIyn who haa succeeded in forming propionic acid from carbonic acid by the action of Bodium-ethyl upon the latter body.-April 1858. E. F.$ Phil. TI~M.,1852 438. FRANKLAND ON A NEW SERIES OF the rational constitution of all the organo-metallic bodies then known by showing that they all possessed a molecular isonomy with the inorganic compounds of the respective metals. The only compoucd which at that time did not coincide with this Y'iew was LSw I G' s so-called ethostibylic acid the formula of which SbC,H,Q, I suggested would probably be found to be erroneous*; and in fact LOWIGhas since announced this to be the case he now assigns to this compound the formula Sb(C,H,),O, ZSbO, which harmonizes perfectly with the general view I ventured to propound. The recent researches of 3%E RC Kt upon the compounds of atibe-thyl although they probably prove the existence of certain new compounds of this radical are by no means conclusive as to the non existence of the bodies originally described by L iiw I G.With regard to those stanethyl compounds which haire been since dis- covered several of them corrcspond exactly with the known oxides of tin; the remainder are also by no means irreconcileable with my hypothesis if we consider the polymeric attributes of stannic acid. Nevertheless I conceive that the formulze and even the existence of some of the more complex stanethyl compounds require con-firmation before these bodies can be employed either for the support or disproof of any general theory of the rational constitu- tion of organo-metallic compounds. Taking then this view of the organo-metallic compounds as my guide I pointed out in a former memoir,$ that the oxygen com-pounds of nitrogen might probably be represented by correspond-ing organic compounds in which one or more equivalents of oxygen were replaced by an organic radical thus to take one example nitric acid by the substitution of methyl should yield the following derivatives :-I.11. 111. IV. V. of which the fourth is already known as oxide of tetramethylam- monium. My attempts to produce these derivatives from the oxygen compounds of nitrogen have hitherto been confined to the binoxide in which I have succeeded in replacing oxygen by ethyl in the manner now to be described. Action of Zincethyl upon Binoxide of Nitrogen. If a small quantity of zincethyl either pure or dissolved in ether be passed up into dry binoxide of nitrogen confined over * Phil.Trans. 1852 442. -t. J. pr. Chem. lxvi 56. S Phil. Trans. cxliii ;442. ACIDS CONTAINING NITROGEN. 81 mercury the binoxide is very slowly but completely absorbed in large quantity without the production of any other gas. The solution may be accelerated by agitation but even then it is exceedingly slow. At the expiration of from one to four clays rhomboidal crystals begin to be deposited and increase in number until the liquid finally solidities. To prepare these crystals in larger quantity about an ounce of zincethyl dissolved in an equal bulk of dry ether was placed in a flat-bottomed flask and supplied with binoxide of nitrogen from a gas holder the gas being thoroughly dried by bubbling through a long series of bulbs filled with concentrated sulphuric acid which also servcd to absorb any traces of nitrous gas that might be formed by atmospheric oxygen gaining access to the interior of the appzratus.The gas was con-ducted into the flask by a tube which terminated just below the cork; whilst a provision was made for its exit by another tube continued to within a short distance of the surfacc of the liquid and which terminated outside the cork in a capillary extremity that could be readily sealed up by the blowpipe mid reopelied at pleasure. Binoxide of nitrogen prepared from copper turnings and nitric acid always contains a considerable percentage of protoxide and it was therefore necessary occasiorially to allow a stream of the gas to flow through the flask so as to prevent the absorption being hindered or stopped by the accumulation of protoxide of nitrogen at other times the exit tube was lierinetically sealed and the gas supplied only as it was absorbed.In this way although the apparatus was in action day and night six weeks elapsed before tlie absorption was completed. Oil another occasion when the action mas accelerated by violent agitation of the liquid for sevcral hours each day the ziiicethyl was saturated in about a fortnight. It was evident that such a process mas little calcula-tcd for the production of considerable quantities of tlic new compound and recourse was therefore had to mechanical means in order to expedite and facilitate the operation. Fig.1is from a photograph of the apparatus employed for this purpose and as it will no doubt prove useful iii other cases for experiments with sparingly soluble gases I will describe it somewliat in detail. A is a copper digester similar to the one 1 have already described for the preparation of zincethyl*; into tlie aperture b is screwed the stopcock c to which can be attached at pleasure the con- densing syringe D made of gun-metal 12 inches long and 0.7 inch in diameter. In this syringe a solid steel piston 12 inch deep works air-tight and the piston-rod passes through a stuffing- box f. The syringe is supplied with gas through the nozzle e to which a flexible tube is attached. When the stopcock c is * Phil. Trans. cxlv 261. G FRANKLAND ON A NEW SERIES OF closed the elevation of the piston produces a vacuum which is instantly filled with gas so soon as the piston has passed the nozzle e.Between e andf the interior of the syringe is grooved loiigitudinally so as to prevent any compression of gas behind the piston when it is drawn up tot. On forcing down the piston and opening the stopcock c it is obvious that the gas occupying the syringe from e to c will be forced into A. By repeating this process it is not difficult for a single operator to compress about twenty atmospheres into A; such a degree of compres-sion exerting upon the piston a pressure of about 114lbs. In each operation about three ounces of zincethyl in ethereal solution was placed in the copper cylinder A and the condensing syringe being attached about twenty atmo- spheres of dry binoxide of uitrogen were introduced; the syringe was unscrewed and the the cylinder A agitated for two or three minutes by rolling upon the floor or otherwise; at the end of which operation the pressure within A was found to be reduced to three or four atmospheres; the process of condensation and agitation being repeated five or six times the copper cylinder becomes so much heated as to require immersion in cold water for a few minutes.At this stage of the process it is also desirable to allow the residual gas in A to escape. This residual gas consists principally of protoxide of nitrogen and hydride of ethyl; the latter derived from the decomposition of zincethyl by a trace of aqueous vapour introduced with the binoxide of nitrogen.By repeating the above series of operations six or eight times the zincethyl becomes saturated and the process is completed. If it be desired to obtain the crystalline compound in a state of perfect puritg it is better to place the zincethylin a wide glass tube open at top and fitting into A ;but in this case very moderate agitation only can be used and consequently the absorp- tion takes place more slowly and the operation requires two or ACIDS CONTAINING NITROGEN. three days for its completion. It is however rarely necessary to have recourse to this modification of the process. At the conclusion of an operation conducted as above with the intervention of a glass tube the contents of the latter consisted of a mass of colourless crystals immersed in an ethereal solution; the latter was poured off and the former were freed from ether by plunging the tube in a water-bath at 90' C.and passing through it a stream of dry carbonic acid. The resulting crystalline mass attracted oxygen from the air with such avidity as to burst into flame when any considerable quantity was freely exposed; it was also instantly decomposed by water and was therefore transferred at once into small glass tubes which were then immediately sealed hermetically. The results of the analtlyscs prove that the new body is formed by the union of an equal number of atoms of zincethyl and binoxide of nitrogen; hut from considerations given below the above formula requires to be doubled and I shall presently shorn that the body is a compound of zincethyl with the zinc salt of a new acid for which I propose the name Diizitroethglic acid Its formula is therefore N,C,H,O,Zn + ZnC,H,.This compound is produced from zincethyl and binoxide of nitrogen according to the following equation :-2'g2y5)} =N,C,H50,Zn + ZnC,H,. Dinitroethylate of zinc and zincethyl is deposited from its ethereal solution in large colourless and transparent rhomboidal crystals which instantly become opaque on exposure to the air owing to the formation of an oxidized product These crystals are tolerably soluble in anhydrous ether without decomposition but they are instantly decomposed by anhydrous alcohol and by water.Exposed to the gradually increasing heat of an oil-bath dinitroethylate of zinc and zincethyl fuses at lOO'C. froths up and begins slowly to evolve gas. At 180' C. the colour darkens and a small quantity of a yellowish liquid of a penetrating odour free from zincethyl and possessing a very powerful alkaline reaction distils over. This liquid neutralized with hydrochloric acid and treated with bichloride of platinum yielded a splendidly crystalline platinum salt which was obtained however in too small quantity to allow of its composition being determined. From 180' to 1909C. dinitroethylate of zinc and zincethyl evolved gas very rapidly and the experiment was then interrupted. The gas consisted of 18.4 per cent.carbonic acid 23.66 per cent. olefiant gas and 57-94per cent. of a mixture of liydride of ethyl nitrogen and protoxide of nitrogen. 62 PRANKLANO ON A NEW SERIES OF When brought into contact with water dinitroethylate of zinc and zincethyl is immediately decomposed with lively effer-vescence. A large quantity of inflammable gas is evolved and a white flocculent substance formed. At the conclusion of the reaction the latter dissolves almost completely forming an opalescent solution resembling milk possessing a powerfully alkaline reaction and a peculiarly bitter taste. In order to ascertain the exact nature of the gas evolved in this reaction some crystals of dinitroethylate of zinc and zincethyl were passed up into an inverted receiver filled with mercixry and were then brought into contact with a small quantity of water.The gas thus collected over mercury possessed an ethereal odour burnt with a slightly luminous flame and was completely soluble in an equal volume of alcoliol. It as perfectly neutral and underwent no change on being treated successively with caustic potash solution and dilute sulphuric acid. The specific gravity of the gas was found to be 1.0515 whicli together with the results of its eudiometrical anaiysis show it to be pure hydride ofethyl. On submitting the milky solution formed by the decomposition of dinitroethylate of zinc and zincethyl in water to a stream of carbonic acid a copious precipitate of carbonate of zinc free from organic matter was thrown dowri the liquid was then heated to boiling and filtered.The filtrate cvapoxated almost to dryness in a water-bath yielded a white radiated crystalline mass which after being reduced to powder pressed between blotting-paper and dried over sulphuric acid was submitted to analysis the results of which correspond with the formula Z(N,C,H,O,Zn) +NO. The composition of this body proves that the action of water upon dinitroethylate of zinc and zincethyl consists in the trans- formation of the zincethyl into oxide of zinc and hydride of ethyl thus The neutr.d dinitroe thylate of ziiic howevc;. thus set at liberty immediately unites nith a second cquivaleiit of oxide of zinc to form the basic salt N2C,H,0,Zn +ZnO whicli is decoinposed by carbonic acid into carbonate of zinc and the neutral salt.Dinitroethylate of zinc crystallizes with half an equivalent of water which is expelled at 100° C. the loss in drying being 3-98 per cent. and 3.75 per cent. respectively whilst the theoretical number is 3.57. Dinitroethylate of zinc is also produced by the direct oxidation ACIDS CONTAINING NITROGEN. of dinitroethylate of zinc and zincethyl in a stream of dry air ethylate of zinc being at the same time formcd the completion of' the oxidation is known by the product ceasing to effervesce in contact with water. This reaction is expressed by the following equation :-N2C,H,0,Zn +C,H6Zn >={N,C,H60,Zn ZnO,C,H,O. 02 When this prodi;ct is treated with water alcohol and bibasic dinitroethylate of zinc are produced N,C,H,O,Zn N,C,H,O,Zn +ZnO HO C,H,O,HO.One of the equivalents of base being removed by carbonic acid the filtered solution of the neutral salt thus obtained was evapo-rated to crystallization and the crystzls heated to 100' for some time; at this temperature they fused and afterwards solidified in cooling to a gummy mass which analysis proved to be the nnhy- drous dinitroethylate of zinc. Finally dinitroethylate of zinc and zincethyl is produced by adding an ethereal solution of zincethyl to anhpdrous dinitroethy- late of zinc and corresponding compounds appear to be formcd under similar circumstances with other salts of dinitroethylic acid. These compounds are evidently of the same nature as that pro- diiced by the union of zincethyl with iodide of zinc which is formed in such large quantity during the preparation of zincethyl.Dinitroethylate of zinc crystallizes in minute colourless ncedles containing half an equivalent of water ~hich they retain \\-hen exposed over sulphuric acid in vacuo. Tlicy fuse below 100' C. and gradually become anhydrous at this temperature. They are very soluble in watcr and in alcohol. The concentrated aqueous solution solidifies on cooling to it white fibrous crystalline mass. Heated suddenly in air to a temperature of about 300° this salt does not deflagrate but it inflames burning rapidly with a beautiful bluish-green flame. When dry dinit+oethylate of zinc is treated with concentrated sulphuric acid and the vessel containing those ingredients is placed in a freezing mixture dinitroethylic acid is liberated; but it is so unsiablc that when the temperature rises a few degrees it begins to effervesce violently and is rapidly decomposed with evolution of gases and white vaponrs.A dilute solution is somewhat more stable ;it may be prepared either by decomposing a dilute solution of dinitroethylate of zinc with dilute sulphuric acid and then distilling in vaczto or by adding to a dilute solution of the baryta salt just sufficient sulphuric acid to precipitate the base. Dilute dinitroethplic acid thns prepared possesses a punpit odour soiiiewliat i.csemtling that of the nitro- FRANKLAND ON A NEW 8ERIES OF fatty acids and an acid taste. It reddens litmus-paper strongly and gradually decomposes even at ordinary temperatures.The acid procured by distillation in wacuo being treated with carbonate of silver the latter dissolved with evolution of carbonic acid. The filtered solution evaporated over sulphuric acid depo- sited light flocculent crystals of dinitroethylate of silver which blackened rapidly. They gave by treatment with nitric acid and subsequent ignition 55.85 per cent. of metallic silver. The formula N,C,H,O,Ag requires 54-82 per cent. Another por-tion of the dilute acid procured by the decomposition of the baryta-salt as described above was saturated with magnesia evaporated to dryness and the residue treated with strong alcohol. Tlie filtered alcoholic solution which contained no trace of sul-phuric acid gave on evaporation dinitrocthylate of magnesia which by treatment with nitric acid and ignition yielded 19.64 pcr cent.of magnesia. The formula N,C,H,O,Mg requires 19.80 per cent. The salts of dinitroethylic acid are all soluble in water and alcohol and most of them crystallize with more or less diaculty. They ere all violently acted upon by concentrated nitric acid the dinitroethylic acid being entirely decomposed and a nitrate of the constituent base produced. Dilute nitric acid acts in the same manner but more slowly. They all fuse at a temperature a little above 100' C. The potash sod%,lime and baryta-salts deflagrate explosively like loose gunpowder at a temperature considerably below redness. Dinitroethylute of Baryta.-N,C,H,O,Ba.This salt is pro-duced by adding caustic baryta in excess to a solution of dini-troethylate of zinc carbonic acid heing passed through the solu- tion until the excess of baryta is precipitated. It is then treated with sulphuretted hydrogen to remove a tracc of oxide of' zinc which is still held in solution. After being heated to boiling for n few minutes and then filtered the solution is concentrated by evaporation and finally dried down to a gummy mass which does not crystallize on cooling. This is anhydrous dinitroethylate of baryta. Dinitroethylate of baryta is uhcrystakable very deliquescent and very soluble in water. Its solution reacts perfectly neutral. Dinitroethylic Ether.-Several attempts were made to prepare this compound by the usual methods of etherification but with only very partial success.When crystallized dinitroethylate of lime is distilled with sulphovinate of potash alcohol comes over mixed with an ethereal liquid which dissolves in water but sepa-rates again on the addition of chloride of calcium in the form of oily drops of a peculiar ethereal odour. I only succeeded however in obtaining such minute quantities of this body as to preclude the possibility of fixing its composition. ACIDS CONTAINING NITROGEN. Dinitroethylate of Lime.-N,C,H,O,Ca +3H0. This salt is readily prepared by treating solution of dinitroethylate of zinc with excess of hydrate of lime passing carbonic acid through the solu- tion and then heating to boiling for a few minutes.The filtered solution deposits on evaporation beautiful silky needles of dini-troethylate of lime which contain three atonis of water two of which are expelled at 100' C. An estimation of lime in this salt gave 20.76per cent. ;the above formula requires 20.59 per cent. Dinitroethylute of Silver is produced by double decomposition from dinitroethylate of baryta and sulphate of silver. It is very soluble in water crystallizes in very light scales and is so speedily decomposed even with little exposure to light that no satisfactory analysis could be made. Double Nitrate and Dinitroethylute of Silver. -AgONO -+ AgON,C,H,O,. This salt is very sparingly soluble in water ; it is precipitated in a crystalline granular form when concentrated solutions of dinitroethylate of zinc and nitrate of silver are mixed.Dinitroethylute of Copper.-2 (N,C4H5Cu0,) + HO. This salt is prepared by mixing solutions of dinitroethylate of baryta and sulphate of copper. The filtered solution is of a magnificent purple colour ; on evaporation in vacuo it yields splendid purple needles which contain half an equivalent of water and may be obtained several inches in length ;they are four-sided prisms. Dinitroethylate of Magnesia N,C,H,MgO,. -Prepared by treating the solution of dinitroethylate of zinc with excess of caustic magnesia boiling and filtering. The filtered solution con- centrated in a water-bath yielded granular crystals which fuse at 100OC. and dry up to a solid amorphous mass. This is the anhydrous salt.DinitrGethylate of Soda N,C+H,O,Na.-Prepared by precipi- tating dinitroethylate of lime with carbonate of soda and evapo- rating the filtrate in a water-bath. The residue being treated with strong alcohol the dinitroethylate of soda dissolves and is thus separated from the excess of carbonate of soda. The alcoholic solution evaporated to dryness iri a water-bath yielded minute scaly crystals which were anhydrous. Products of the Decomposition of Dinitroethylic Acid. I have stated that when dinitroethylic acid is liberated from its salts by the addition of concentrated sulphuric acid it is rapidly decomposed even at 0' C. I have examined the products of this decomposition in the case of the lime-salt with the following results. A quantity of crystals of dinitroethylate of lime in coarse powder was placed in an apparatus in which it could be gradually decomposed by concentrated sulphuric acid the gaseous products collected and their weight accurately ascertained.The rapidity FRANKLAND ON A NEW SERIES OF of decomposition was moderated by the external application of cold water. At the conclusion of the decomposition it was found that the weight of the gaseous products evolved was equal to 30.6 per cent. of the meight of the lime-salt employed. The weight of gaseous products is therefore almost exactly one-half of the weight of the anhydrous acid contained in the lime-salt (59.6 per cent .) . The liquid and solid products of the operation contained sulphate of lime sulphovinate of lime and sulphate of ammonia or ethylamine.These gaseous products after streaming through concentrated sulphuric acid mere collectcd over mercury and sub-mitted to eudiornetrical investigation. The specific gravity was found to be 1.3601. The mean percentage composition of the gas was Binoxide of nitrogen . . 8.90 Olefiant gas . . 24-24 Protoside of nitrogcn . . 60.65 Nitrogen . 6-21 100.0 This result is confirmed by the specific gravity of the gas as is seen from the following calculations :-Per cent. Specific amount. gravity. Binoxide of nitrogen . . . 8.90 x 1*0365= 9.2249 Protoxide of nitrogen . . 60.65 x 15202= 92.2001 .- Olefiant gas . .. .. -. 2::ii}x *96'74= 294573 Nitrogen -130.8823 100*00 --1.3088 100 Foundbyexperiment .. . . . . . 1.3601 1:had anticipated that the decomposition of dinitroethylate of lime by sulphuric acid would yield either protoethlde of nitrogen (NC,HS) or ethoprotosidc of nitrogen (NC,H,O) but the action of the concentrated acid evidently proceeds too far for the produc- tion of this result. Further experiments must decide whether or not the cmployment of a more dilute acid for the decomposition mill lead to the production of onc of these compounds. Action of Zincmethyl upon Rinoaide cf Nitrogen Dinitromethylate of Zinc and Zincmethyl.-Zincmethyl absorbs binoside of nitrogen much more slowly than zincethyl takes up the same gas ;nevertheless at the ordinary atmospheric pressure the two bodies padually unite and form colourless crystalline needles closely resembling in all their reactions the dinitroethylate of zinc and zincethyl.I have made no analyses of this body but ACIDS CONTAINING NITROGEN. considering the homology existing between zincethyl and xinc- methyl together with the product of its decomposition by water there can scarcely be a doubt that it is dinitromethylate of zinc and zincmethyl and that its formula is N,C,H,O,Zn +C,H,Zn. It rapidly oxidizes in the air and takes fire when exposed in considerable quantity. It is instantly decomposed by water giving light carburetted hydrogen and an opalescent solution of basic dinitromethylate of zinc. Dinilromethylute of Zinc N,C,H,O,Zn +H0.-A quantity of the dinitromethylate of zinc and zincmethyl mas prepared by the action of compressed binoxide of nitrogen upon zincmethyl in the strong copper vessel above described.The resulting crystalline compound was decomposed by water and the opalescent solution being treated with carbonic acid boiled and filtered yielded on evaporation minute crystals of dinitromethylate of zinc. Dinilronaethykute of Soda N2C2H,0,Na +2HO.-This salt is formed by treating a solution of dinitromethylate of zinc with car-bonate of soda evaporating to dryness and treating the residue with strong alcohol. Dinitromethylate of soda dissolves and the filtered solution on evaporation deposits crystals which after drying at 10QoC. yielded 25.83 per cent. of soda; the above formula requires 26.72 per cent. Dinitromethylate of soda is very soluble both in water and alcohol ;it ileflagratx violently when heated and in other rcspccts closely resembles the cor-responding salt of dini troethylic acid.These determinations although very imperfect and incomplete establish the existence of a class of salts containing dinitromethylic acid homologous with the dinitroethylates; and there can be little doubt that the zinc compounds of the other alcohol-radicals will yield corresponding acids when treated with binoxide of nitrogen. It is difficult to form any satisfactory hypothesis relative to the rational constitution of this series of acids they may be regarded as belonging to the type of nitrous acid containing a double atom of nitrogen and in which one atom of oxygen has been replaced by an alcohol radical thus- or they may be viewed as constructed upon the hyponitrous acid F.WGHLER AND H. BUFF type one equivalent of oxygen being replaced by an alcohol radical and a second atom by binoxide of nitrogen thus- Without attaching much value to either hypothesis I prefer the latter. By analogous processes there can be little doubt that many new series of organic acids may he derived from inorganic acids by the replacement of one or more atoms of oxygen by an alcohol-radical; in fact my pupil Mr. HOBSON now studying a new series con-is taining sulphur produced by the action of zincethyl and its homologues upon sulphurous acid the ethyl acid of this series is formed by the replacement of one equivalent of oxygen in three equivalents of sulphurous acid by an alcohol-radical.The following Table exhibits the compounds of the new series of acids which have been described in the foregoing pages Formule. DinitroethyIic acid . . . . . N,C,H,O,H. Dinitroethylate of silver. . . . . N,C4H,0,Ag. Dinitroethylate of copper . . . 2(N2C,H,04Cu) +HO. Dinitroethylate of zinc (crystallized) . 2(N,C,H,O,Zn) -t HO. Dinitroethylate of zinc (anhydrous) . . N2C,H,04Zn. Dinitroethylate of baryta . . . . N,C,H,O,Ba. Dinitroethylate of lime . . . . . N,C,H,O,Ca+ 3H0. Dinitroethylate of magnesia . . . N$,H,O,Mg. Dinitroethylate of soda . . . N,C,H,O,Na. Double nitrate and dinitroethylate of silver . NO,Ag + N,C,H,O,Ag. DinitroethyIate of zinc and zincethyl . . N,C,B,O,Zn +C,H,Zn.Dinitromethylic acid . . . . N,C,H,O,H. Dinitromethylate of zinc . . N,C,H,O,Zn +Ho. Dinitromethylate of soda . . N,C,H,O,Na t 2H0. Dinitromethylate of zinc and zincmethyl N2C2H,0,Zn t C2H,Zn. On some new Compounds of Silicon,* BY F. WOHLERAND H. BUFF. Siliciuretted Hydrogen.-A gaseous compound of silicon and hydrogen is produced when a bar of aluminium containing silicon is connected with the positive pole of a Bunsen’s battery of 8 to 12cells and made to dip into a solution of chloride of sodium. The aluminium then dissolves in the form of chloride a consider-* Ann. Pharm. ciii 218 ;civ 94. ON SOME NEW COMPOUNDS OF SILICON. able quantity of gas is evolved at its surface and many of the gas-bubbles as they escape into the air take fire spontaneously burning with a white light and diffusing a white fume.When the gas is collected in a tube over water and bubbles of oxygen passed up into it each successive bubble produces at first a brilliant white light and a copious white fume; but this effect gradually diminishes in intensity and at last the remaining gas mill no longer burn spontaneously by contact with oxygen. This residual gas is hydrogen ; the spontaneously inflammable gas which forms but a small portion of the mixture is siliciuretted hydrogen. When the gaseous mixture is made to escape from a glass jar provided with a stop-cock it burns in a jet and deposits silica round the orifice. A piece of white porcelain held in the flame becomes stained with a brown deposit of silicon; and if the gas be made to pass through a narrow glass tube and heated till the glass softens a deposit of silicon is likewise obtained and the gas which issues from the tube is no longer spontaneously inflam- mable.The compound has not yet bcen analysed quantitatively. The formation of siliciuretted hydrogen appears to be due to a secondary action accompanying the electrolysis of the saline solution. The aluminium forming the positive pole of the battery combines with the chlorine and dissolves; but the quantity of aluminium removed is about one-fourth greater than that which is equivalent to the quantity of chlorine eliminated from the solution. This excess of aluminium is found to be removed in the form of alumina uniting with oxygen derived from the water of the solution.The equivalent quantity of hydrogen is of course evolved and part of it enters into combination with the silicon contained in the aluminium. The compound has not yet been obtained by a purely chemical reaction; but it has been observed that the hydrogen evolved when aluminium dissolver in hydro- chloric acid burns with a brighter flame than pure hydrogen and yields a small deposit of silica. Chloride of Silicon and Hydrogen. Si,Cl, 2HCl.-This com-pound is obtaincd by heating crystalline silicon to a temperature somewhat below redness in a stream of hydrochloric acid gas. The silicon in fine powder is disposed throughout the entire length of a long glass tube one end of which is connected with an apparatus for evolving dry hydrochloric acid gas while to the other is attached a long-legged U-tube cooled by a mixture of ice and salt and fitted with an escape tube having its aperture widened like a funnel and dipping into a large vessel of ice-cold water.As soon as the apparatus ia filled with hydrochloric acid gas the tube is surrounded with hot coals and heated to a temperature short of visible redness; at a higher temperature the ordinary terchloride of silicon would be formed. The hydrochloric acid is F. WOHLER AND H. BUFF then decomposed; bubbles of inflammable hydrogen gas pass through the water and at the same time a white substance which is a new oxide of silicon is separated being produced by the action of the water on a portion of the ctiloride of silicon and hydrogen which is carried forward with the stream of hydrogen.At the end of the operation the U-tube is found to contain a turbid liquid which is the chloride of silicon and -hydrogen mixed with other compounds. When subjected to fractioiinl distillation it begins to boil at about 28' or 30' C the temperature hawever quickly rising to between $0' arid 43' between which limits the largest portion of the product which is the chloride of silicon and hydrogen passes over. The temperature ultimately rises to 60° and on one occasion it rose to 92O. Chloride of silicon and hydrogen is a colourless very mobile liquid which has a very pungent odour fumes strongly in the air and covers everything aroiind it with a white film.Its boiling point is about 42'; spccific grabity 1.65. It docs not conduct electricity. Its vapour is as inflammable as ether-rapour and burns with a faintly luminous greenish flame difl'using vapours of silica and hydrochloric acid. When a Cew drops of the liqiiid are passed up into oxygen gas in an eudiometer tube over merciiry and left to evaporate a gaseous niivture is formed which explodes violently when an electric spark is passe6 through it producing a whits flame and covering the inner surface of the tube wit11 a white film of silicic acid. The residual gas consists of hydrochloric acid and terchloride of silicon the compound having given up half its silicon to form silicic acid. The vapoiir passed through a imrrow red-hot tube is quickly decomposed into amorphous silicon which coats the inside of the tube with a brown specular deposit and a mixture of hydrochloric acid and terchloride of silicon.Herice thc necessity of keeping the heat below redness during the preparation. When the vppour is passed over aluminium in the state of fusion it is very easily decomposed hydrogen being set free chloride of aluminium subliming and the reinainder of the aluminium becoming covered with a loose crust of crystallized silicon. The tube is at the same time coated internally with amorphous silicon in consequence of part of the compound being decomposed merely by the heat in the manner above described. In contact 1~6th matcr the compound is instantly decomposecl with great rise of temperature yielding hydrochloric acid and hydrated sesquioxide of silicon (1'.93). If a smali dish full of the liquid chloridc be placed over a surface of watcr and the n-liolc covered with a bell-jar the liquid quickly disappears aiid the surface of the water becomes covered with a thick crust of the oxide. The rapour of the chloride is rapidly absorbed by alcolicjl and ON SOME NEW COMPOUPU'DS OF SILICON. ether without separation of oxide. The solutions fume in the air and when left to evaporate over sulpliuric acid and hydrate of lime they leave a partly earthy partly translucent oxide which appears to coiitain an ethyl-compound (silicic ether 3). The alcoholic solution solidifies after a while into a translucent jelly. The preceding reactions sufficiently indicate the composition of the new chloride which is further confirmed by the analysis giving as a mean result 3 9-14 p.c. silicon and 80.913p. c. chlorine while the formula Si,Cl, 2WC1 requires 19.18 Si and 79-92 C1. Bromide of Silicon and Hydrogen. Si,Br, 2HBr.-Prepared like the chloride. It is at first coloured yellow by free bromine but may be decolorised by means of' mercury. It is a colourless liquid which fumes very strongly in the air. Its specific gravity is approximately 2.5. When immersed in water it is decomposed like the chloride but immediately becomes covered with a coat of oxide which for a while protects it from further decomposition. Iodide of Silicon and Hydrogen. Si213. 2HI.-Prepared like the chloride and bromide excepting that there is no necessity for a receiver inasmuch as the iodide being less volatile and solid at ordinary temperatures condenses at the cool end of the tube in which the decompositioii takes place.It forms a dark red brittle mass which fumes strongly in the air its colour then changing first to bright vermilion-red and ultimately to snow-white. It melts easily and solidifies in the crystalline form on cooling. At a higher temperature it boils and distils over. In the state of vapour it appears to be colonrless. In water it instantly assumes a vermilion-red colour and is slowly decomposed. Bisulphide of carboii dissolves it in larger quantity forming a blood-red solution which when concentrated by distil- lation deposits the compound in dark red crystals.Hydrated Oxide of Silicon Si .0,2HO. -Produced in the decomposition of the preceding compounds by water e.g. Si2Cl,.2HC1 + 5H0 = 5HC1 + Si,03.2H0. It is most readily obtained as a secondary product in the prepara- C. 0'water must be cooled to The tion of the chloride (p. 92). as the oxide is decomposed by it at ordinary temperatures. The oxide is collected on a filter and washed with ice-cold water ;the filter gradually but strongly pressed between bibulons paper ; aid the oxide dried over oil of vitriol. It is a siiow-white amorphous body very light and bulky znd floats in water but sinks in ether. Alkalies even ammonia and their carbonates decomposes it with frothy evolution of hydrogen and formation of alkaline silicates.It is not acted upon by any acid except hydroflnoric acid which dissolves it with rapid evolu- tion of hyclrogeu. It may be heated to 300' C. or above without F. W~HLERAND H. BUFF giving off water or undergoing any other change. At a stronger heat it takes fire and glows brightly with a phosphorescent light giving off hydrogen gas which takes fire with explosion. Heated in oxygen gas it burns with a dazzling light. It likewise burns when heated in a covered crucible but the residual silica has more or less of a brown colour arising from admixture of amorphous silicon and the inner surface of the crucible becomes coated with silica. These appearances are due to the evolution and subsequent decomposition of siliciurett ed hydrogen.In fact when the com- pound is heated in a tube it gives off a gas which fumes in the air but does not take fire spontaneously in consequence of being mixed with free hydrogen; but when set on fire it burns with separation of silica. When the hydrate is dried in a stream of hydrogen then heated to redness and the gas which escapes is passed through a narrow tube heated to redness at one part, the tube becomes coated with a brown speculum of silicon and the escaping gas when set on fire yields a deposit of silicic acid on a glass plate held against the flame. If siliciuretted Iiydro-gen has the composition SiH the decomposition of the hydrated oxide may be represented by the equation 3(Si20,.2HO) = 5Si0 + 5H + SiH. Hydrated oxide of silicon is somewhat soluble in water The acid filtrate obtained in its preparation is constantly filled with rising bubbles of hydrogen presenting the appearance of fermenta- tion and the gas is evolved with such force as to project the stopper from the vessel if closed.The decomposition may be still further accelerated by heat. The solution also gives off abundance of hydrogen when mixed with ammonia. It is a powerful redu-cing agent. It precipitates gold and palladium from the solutions of their chlorides the latter perhaps mixed with silicate of'palladium. With nitrate of silver it first forms a white precipitate of chloride of silver but afterwards throws down a brown substance containing silicon as well as silver. Mixed with a cupric salt arid then with an alkali it throws down yellow cuprous hydrate.With corrosive sublimate it forms a precipitate of calomel which if left in con- tact with excess of the solution is gradually reduced to the grey metal. From selenious tellurous and sulphurous acids it preci- pitates respectively selenium tellurium and sulphur. It instantly decolorises a solution of permanganate of potash. It has no action on chromic acid or on solutions of platinum iridium or indigo. The composition of the hydrated oxide as given by analysis, agrees nearly with the above formula. Two aualyses gave in 100 parts 50.95 and 50.99 Si; 27-34and 27.68 0; 21.68 and 21-33 HO ; the formula Si,O,. 2H0 requiring 50.35 Si 28.37 0 and 21.28 HO. In some cases however a larger proportion ON SOME NEW COMPOUNDS OF SILICON.even 52-75 p. c. silicon was obtained and this together with cer-tain reactions of the compound leads to the supposition that there exists a lower oxide of silicon probably SiO and a corresponding chloride. The lower oxide appears to be that which dissolves in water and produces the reducing effects above mentioned ; a portion of the oxide which had yielded above 52 p. c. of silicon was again mixed with water and again washed on a filter with water at the ordinary temperature till the wash-water exhibited with nitrate of silver no longer a precipitate but merely a brownish colouring. The residual oxide was found to contain only 49.05 p. c. silicon. The chloride corresponding to the lower oxide (SiCl?) appears to be gaseous at ordinary temperatures.In one preparation amorphous silicon in considerable quantity was exposed to the action of hydrochloric gas at a temperature below redness. The reaction took place with great facility and hydrogen was abun-dantly evolved ; but the U tube though cooled to -15O C. was afterwards found to contain very little liquid chloride ; while on the other hand the water through which the gas passed after leaving the U tube contained a large quantity of white oxide which burnt with peculiar brightness yielding a brown coloured silica. This was the oxide which was found to contain 52-75 per cent of silica. Nitride ofSiZicon.*-This compound is obtained by the action of ammonia on either of the chlorides of silicon.It is perfectly white amorphous infusible and unalterable at the hightest temperatures and does not oxidise when ignited in contact with the air. It is not acted upon by alkalies in solution or by acids excepting hydrofluoric acid which converts it into silicofluoride of ammonium. When fused with hydrate of potash it gives off a larger quantity of ammonia and yields silicate of potash. Heated with red oxide of lead it reduces the lead with incandescence and formation of nitrous acid. Like nitride of boron it eliminates carbon from carbonic acid. Fused with carbonate of potash it yields silicate and cyanate of potash from which urea may be prepared; if the nitride of silicon is in excess cyanide of potassium is formed at the same time.* H. Sain te-Claire Deville and W ohler. Ann.Pharm. civ 356. 96 On Chloride of Ethylene.* By A. Wurtz. WHENpentachlorit 3 of phosphorus is gradually added to g,ycol which is kept cool a brisk action takes place; hydrochloric acid being evolved and the glycol being converted into a viscid mass without blackening. On adding more of the pentachloride the mixture becomes more fluid and after a certain time the erohtioii of hydrochloric acid ceases; and any additional quantity of the pentachloride dissolves in the liquid while hot but separates again 011 cooling. If the product be then distilled it begins to boil below 100"; bnt the boiling point gradually rises to above 150" and the residue ultimately blackens. The distillate is colourlcss arid when redistilled passes over completely below 115".It con-tains oxychloride of phosphorus which may be decomposed by agitation vi ith water and an oily liquid then separatesl whic!~ when washed with water dried by chloride of ca1cium and rectified exhibits the properties and cornpositiori of chloride of ethylene C,H,Cl,. Its formation is represented by the equation Chloride of ethylene stands to the bi-acid compound glycol in the same relation as chloride of ethyl to the mono-acid conipoiind alcohol. C,I160 + HC1 = H,O + C4€15Cl C,H60 + 213Cl = 2H,O + C,H,Cl it is the hydrochloric etlzer of glycol. * Compt. Rend. xlv. 228. Ann. Ch. Pharm. clv. 174.