MR. 0;. B. BUCKTON ON 11.-On the Ptatino-tersulphocyanides and the Platino-bisulpho-cyanides two new series of salts and their decompositions. BY GEORGE BOWDLER F.L.S. BUCKTON Although the salts of platinum have been pretty closely studied by chemists and are perhaps found to be more numerous than those of any other metal there is some room for surprise that scarcely any attention has been paid to their action upon sulphocyanogen com- pounds. The only notice I have been able to find of a sulphocyanide of platinum is that made by Grotthus and quoted by Brande stating it to occur as a bulky flocculent precipitate of a yellow colour soluble in acids and in solutions of chloride of potassium and sodium but thrown down again from these solutions by alcohol.Hitherto I have not met with a substance answering these properties unless it should prove to be identical with that last described in this paper. The addition of bichloride of platinum to a cold solution of sulpho-cyanide of potassium alone gives rise to the ordinary double salt chloroplatinate of potassium with disengagement of hydrosulpho-cyanic acid. If on the other hand a strong solution of sulphocyanide of potassium be previously heated to 70' or 80' C. there is no precipitation but the liquid changes to a deep port-wine-red colour accompanied with a rise in temperature. On standing this solution deposits a multitude of brilliant red or gold-coloured plates which are very soluble in hot water. By this process much waste of sulpho-cyanide of potassium is unavoidable from the presence of free hydro- chloric acid which also decomposes the new compound into a brown flocculent precipitate if the temperature rises above a certain point.A more profitable operation consists in dissolving in a moderate quantity of water five parts of pure sulphocyanide of potassium weighed in an anhydrous state which is best obtained by fusion. Four parts of dry chloroplatinate of potassium are then added by degrees to the solution combination with which may be promoted by THE PLATINO-SULYHOCYANIDES. a heat regulated below the boiling point. A deficiency of the sulpho- cyanide must be carefully avoided as in such a case the above-mentioned brown product is an invariable result rendering the purification of the crystals exceedingly difficult.After filtering the hot liquid it is set apart to cool when the new salt is deposited in beautiful and regular hexagons often of a large size. To remove traces of chloride of potassium one product of the reaction the crystals may be redissolved in boiling alcohol and passed through a filter surrounded with hot water a necessary precaution to prevent obstruction from a too rapid crystallization. The solid salt dissolves in 12parts of water at 60' C. but is far more soluble in boiling water and still more so in hot alcohol. The crystals which are of a deep carmine red belong to the rhombohedra1 or three and one-membered system. From the alcoholic solution they often take the form of double six-sided pyramids united base to base with apices truncated ; but the aqueous solution usually furnishes hexagonal plates.With access of air this substance ignites at a very gentle heat with a blue sulphurous flame and peculiar odour. A red heat resolves it into sulphocyanide of potassium gaseous products and reduced platinum In common with all the soluble salts to be described it has an exceedingly nauseous taste and the colour is so intense that one drop of a saturated solution will give a distinct yellow tinge to a gallon of water. A pure solution does not strike a blood-red colour with sesqui- chloride of iron; but such a mixture becomes nearly black and opaque on heating from the forniation of a substance in heavy lustrous grains. Caustic potassa converts the red salt into a red gelatinous mass without evolution of ammonia which however is freely dis- engaged on ignition with soda-lime.Acted on by hydrosulphuric acid the salt is resolved into hydrosulphocyanic acid sulphocyanide of potassium and bisulphide of platinum. It is also decomposed by concentrated sulphnric and hydrochloric acids. The action of nitric acid will be afterwards referred to. The dry salt is quite permanent at ordinary temperatures ;but from its inability to bear a high degree of heat without decomposition most of the compounds to be described were dried in vacuo over sulphuric acid previous to analysis. The potassium was separated by precipitating the new acid with nitrate of silver. After removing the excess by hydrochloric acid the alkali was weighed in the form of chloroplatinate of potas-sium.BIR. G. B. BUCKTON ON The platinum was determined by .igniting the bisulphide preci-pitated by sulphide of ammonium. The carbon was estimated by burning the substance in a stream of air and oxygen observing the usual precautions for absorbing traces of nitrous and sulphurous acids. And here I may be allowed to bear a grateful testimony to the readiness and convenience in determinations of this kind afforded by the gas-furnace for organic analysis lately constructed and described by Dr. Hofmann. From the abrupt decomposition and presence of both sulphur and nitrogen in the substances to be noticed their determinations may be said to present more than usual difficulty.Attention however to slow burning is all that is necessary in these cases to procure accurate results. By the simple addition of another tube and piston nitrogen determinations may be also coil- ducted Rith great neatness and accuracy. The sulphur was determined by oxydizing the substance with chlorate of potassa and hydrochloric acid assisted by gentle heat. Sufficient boiling water was then added to hold in solution any chloroplatinat,e that might be formed and the precipitate from chloride of barium was filtered off whilst hot. This method was found to obviate the tedious washings which are necessary when fuming nitric acid or a nitrate is employed Its substitution is strongly recommended in the analysis of volatile sulphuretted com- pounds.I. 0.7554 gnn. of substance gave 0.6030 pn. of chloroplatinate of potassium. I. 0.7050 , , , 0.2230 , platinum. 11. I0.9132 , , , 0.2876 , platinum. 111. 0.5980 , , , 0.1900 , platinum. I. 1.0900 , , , 0.4582 , carbonic acid. 11. { 1.0160 , , , 0.4390 , carbonic acid. J. ‘0.7264 , , , 1.5705 , chloropiatinate of ammonium. 11. 1.0044 , , , 2.1888 , chloroplatinate of ammonium. 111. t 0.6628 , , , 1.4492 , chloroplatinate of ammonium. 1. 0.5628 , , , 1.2600 , sulphate of baryta. 11. 0.4030 , , , 0.9096 , sulphate of barj-ta. The corresponding percentages to these nurnbers are 1. 11. 1x1. 7 I Potassium 12.73 Platinum 31 -64 31*49 31.77 Carbon 11.64 11-78 -Nitrogen 13.54 13.56 13-66 Sulph UP 30.70 30.96 -The carbon nitrogen and sulphur are therefore in the proportion THE ,~LBTTNO-SULPHOCYANIDES.to constitute three equivalents of sulphocyanogen. Their union with one equivalent of platinum forms the new radical which takes up another equivalent of potassium in constructing the above salt. The name proposed for the new substance is ptatino-tersukhu-cyanide of potas&m and the formula KPtC6N3S6 or KPt 3 CyS,. The theoretical and experimental numbers are subjoined : -Theory. Experimental mean. P equiv. of potassium 39 12.52 12-73 1 , platinum 99 31.73 31.63 6 , carbon 36 1‘1.53 11.72 3 6 , , nitrogen sulphur 42 96 - 13.46 30.76 13.58 30.83 312 I oo*oo There has been therefore in the reaction a simple substitution of 3 equivs.of sulphocyanogen for 3 equivs. of chlorine in the ehloro- platinate of potassium employed Expressed in equation ; K PtCl + 3 KCyS,= KPt 3 CyS + 3 KCI. An interesting method of controlling this formula presented itself in estimating the quantity of sulphocyanogen in the compound thus comprising in one analysis the whole of the carbon nitrogen and sulphur present. A solution of the salt was precipitated by sulphide of amtnonium and heated on the water-bath until all trace of free ammonia was lost. After adding acetic acid the bisulphide of plati-num was filtered off and the clear liquid treated with nitrate of silver. The formation of acetate of silver was prevented by addition of a few drops of nitric acid. 0.7150 grms. of substance gave 1.1275 grms.of sulphocyanide of silver equiv. to 0.3999 grms. of sulphocyanogen. Calculated for 100 parts. Required. Found. 3 equivs of sulphocyanogen 55.76 55 90 We may therefore safely infer the correctness of the following equation MR. G. B. BUCKTON ON Subplatino-tersulphocyanideof mercury appears immediately as a copious curdy precipitate on adding nitrate of suboxide of mercury to a solution of the new potassium salt. It is of a deep orange colour which changes to a pale primrose-yellow on raising the liquid to ebullition. After washing it was gathered on a filter pressed with paper and dried in uacuo over sulphuric acid. Freed from water it will bear a considerable temperature without change. Heated in the air-bath to between 140' and 150' C.it suddenly swells up into a singular metallic and arborescent looking substance showing some resemblance to coarse tea.* At the same time there is a rush of gas which spontaneously kindles. No further change is observed up to 250' but below redness mer-curial fumes and cyanogen gas are liberated; and finally if exposed in an open crucible the mass fires like tinder leaving a residue of platinum. I. 0.5150 grm. of substance gave 0.1076 grm. of platinum. ,f rr. POOIO , , 0.2120 , platinum. 111. 0.9734 , ?? , 0.2052 , platinum. $9 IV. 0.9024 , , 0.2531 , carbonic acid. which expressed in 100 parts give I. 11. 111. IV. Platinum 20-87 21.19 2 1 *08 -Carbon --7.68 agreeing with the formula -Theory. Experimental mean.2 equivs. of mercury 1 , platinum 6 , carbon 200 99 36 42-28 20.95 7.61 -121.04 7.68 3 6 , , nitrogen sulphur 42 96- 8.87 20.29 - 473 100*00 In common with all the examined salts of this series subplatino- tersulphocyanide of mercury yields by dry distillation in a retort the * I have not been able sufficiently to examine this compound or arrive at any certain formula. I will only mention that 0.7092 grm. gave by ignition 0-1662 grm. of plati-num which is equivalent to 23-49 per cent. THE PLATTNO-SULPHOCYANIDES. beak of which is placed under water much bisulphide of carbon. This circumstance together with the fact verified by experiment that nitrogen also is a product explains the brisk evolution of gas and ready inflammation of the substance noticed above.The nitrogen gas was identified by conducting the reaction in a sealed tube and sub- sequently collecting the gas over water. Platino-tet.sulphocyanide of Iron.-When a slightly acid solution of sulphate of iron is added to a concentrated solution of platino-ter- sulphocyanide of potassium a black crystalline substance falls which is insoluble in water and also in alcohol. Under the microscope these grains appear as shining six-sided figures with rounded edges. They are not affected by dilute sulphu- ric hydrochloric or nitric acid but concentrated nitric acid dissolves them with formation of sulphuric acid. A cold solution of potassa converts them into sesquioxide of iron and a yellow liquid containing platinum and sulphocyanogen.To estimate the platinum in this salt a weighed portion was dis- solved in aqua regia and after dilution with water hydrosulphuric acid was passed in excess and the precipitate ignited. The filtrate treated with ammonia gave the iron as sesquioxide. The other analyses were made in the usual manner portions from different pre- parations being employed. I. 0.9966 ps. of substance gave 0.1334 grms. of sesquioxide of iron. I. , 0.3317 platiiium. 9) 1 ? 0.1426 sesquioxide of iron. 31. 6 1-(288 1s 11.1 , 0.3412 platinum. , 0.1448 sesquioxide of iron. 1 , 0.4321 carbonic acid. ?f ,? ? 0.4475 carbonic acid. T. 1.0044 , ? ,) 2.1888 chloroplatinate of ammonium. 11. [ 05956 , ?? ,? 1.3360 chloroplatinate of ammonium.11 I. 1*03172 , , 1.6775 sulphate of baryta. The percentage composition is I. XI. 111. Iron 9.35 9.51 8.99 Platinum 33.29 33.16 Carbon 11.85 11*60 Nitrogen 13.50 13.96 Sulphur 32.08 The formula is FePt 3CyS,. MR. G. B. BUCKTON ON The theoretical and experimental numbers are Theory. Experimetal Mean. 1 equiv. o f iron 28 9.30 9-28 1 , platinum 99 32.90 33 23 6 , carbon 36 1 1*96 11.73 3 , nitrogen 42 13.95 13.73 6 , sulphur 96 31.89 32.08 301 f 00.00 A substance exactly similar in appearance and general character is produced by substituting the salts of the sesquioxide of iron. It falls however only 011 boiling the mixed solutions. A qualitative examination is all that I have been able to bestow upon this com-pound.Platino-tersul~hocyanideof Silver is prepared by decomposing a solution of the potassium salt by nitrate of silver. It is a heavy curdy substance of a deep orange colour which shrinks and aggluti- nates into a tenacious mass when boiled in water but again hardens on cooling. Agentle heat causes the dry salt to swell much igniting with a blue flame if air be present. It is fusible by the blow-pipe into a metallic bead of platinum and silver by which behaviour it may be readily distinguished from the mercury salt. When recently precipitated it is soluble in cold ammonia but decomposition ensues at a higher temperature. Nitric acid also acts energetically upon it with disengagement of binoxide of nitrogen ; a yellow substance is thrown down; and sulphuric acid is formed during the re-action.The behaviour of hot caustic potassa towards the silver salt pre- sented a convenient method of estimating the proportional quan-tities of the platinum and silver contained. By this treatment 1 equiv. of platino-tersulphocyanide of silver is resolved into 3 equivs. of sulphocyanide of potassium with precipitation of binoxide of platinurn and oxide of silver in the form of a black heavy powder. Ag Yt3(CyS,) +3KO=3 (K,CyS,)+PtO,+AgO. 0.6513 grm. of substance gave by igniting the oxides 0.3538 , platinum and silver. 0.9038 , substance gave by ignition in oxygen and air 0.3061 , of carbonic acid. THE PLATINO-SULPHOCTANIDES. This accords with the above formula for the silver-salt thus : -Theory.Found. 1 equiv. of silver 1 , platinum 991 54.33 5432 6 , carbon 36 9.44 9.10 3 , nitrogen 42 11912 -6 , sulphur 96 25.11 -381 100*00 Here it may be mentioned that the platino-tersulphocyanides in many respects bear a strong resemblance to the sulphocyanides. ,4s an example it may be noticed that both their silver salts form double crystallizable compounds with sulphocyanide of potassium. The parallellism of these two substances is further carried out in their immediate decomposition by dilution with water. In the case of the double sulphocyanide of silver and potassium a simple separation of the two salts takes place every trace of silver being thrown down as sulphocyanide. In the double platinum compounds the reaction consists in a transfer of the potassium to the platinum acid and precipitation of the silver as sulphocyanide.This last substance (the product of the latter experiment) was identified by analysis as well as by a careful examination of its properties.* The clear red liquid filtered from the precipitate consisted of a solution of platino-tcrsulphocyanide of potassium. Expressed by an equation it stands thus Ag Pt 3 (CyS,) + KCyS2=AgCyS,+ KPt 3 (CyS,). Platino-tersulphocyanide of silver is insoluble in an excess of platino-tersulphocyanide of potassium. Plutino-tersu~hocyanideof Lead.-This is a remarkably beautiful substance thrown down in the form of innumerable golden plates on uniting the concentrated solutions of acetate of lead and platino-ter- sulphocyanide of potassium.The crystals which are minute but I. 0.8594 grm. of precipitate burnt in oxygen and air gave 0,2164 , carbonic acid or 6.87 per cent of carbon. 11. 0.8548 , precipitate burnt in oxygen Cyrc,. gave 0.2196 , carbonic acid or 6.99 per cent of carbon. Sulphocyanide of silver requires Calculated. Experimental mean. Carbon 7.23 6-94 MR. G,B. BUCKTON ON very regular hexagons are soluble in alcohol but less so in cold water with which they should be well washed on the filter for purifi- cation as recrystallization from a hot solution does not offer a good method from the speedy deposition of sulphate of lead and disengage- ment of hydrosulphocyanic acid an explanation of this decompo- sition will be offered when we treat of the salts of the next series.The general properties of platino-tersulphocyanide of lead are such as might have been anticipated from the examination of the iron and silver compounds and leave no doubt of its composition. Attempts were made to obtain analytical numbers but from the difficulty of procuring the substance chemically pure they are not sufficiently accurate for insertion. A subsalt of a brilliant red colour insoluble in water and in alcohol is precipitated on substituting the subacetate of lead for the neutral acetate. Its ready solubility in dilute nitric or acetic acid presented the most ready method of estimating the lead in combi- nation by precipitation as sulphate. 05000 grm.of substance gave 0.3100 grm. of snlphate of lead equivalent to 42.36 parts of lead in 100. If reliance may be placed upon this single analysis it satisfactorily points to the basic sulphocyanideof lead as its analogue. The formula for the new compound thus would be Pb Pt 3(CyS,) +PbO which requires for Theory. Experiment. 2equivalents of lead 43.36 43-46 A substance similar in properties but much paler in colour may be procured by the addition of ammonia (not in excess) to the solution of platino-tersulphocyanideof lead. Hydroplatino-tersu~hocyanicacid is most conveniently procured by precipitating a warm concentrated solution of platino-tersulpho-cyanide of' lead by sulphuric acid. The filtrate which is of a fine red colour contains tbe new acid which is capable of forming all the salts above described and deports itself in the usual manner of a true acid.From its deep hue it can be scarcely proved to redden litmus paper but it presents a decided sour and then very rough taste to the tongue. It freely displaces carbonic acid from the alkalies and dissolves metallic zinc with liberation of hydrogen and pro-duction of a bright yellow insoluble compound hitherto unexamined. When concentrated on the water-bath decomposition speedily com- THE PLATINO-SULPHOCYANIDES. mences; and on approaching dryness a brown amorphous mass very rich in platinum remains in the dish. By gentle distillation an acid liquid passes over in considerable quantity accompanied with the odour of hydrocyanic acid.The distillate furnished with nitrate of silver a copious white precipitate which on examination proved to be a mixture of cyanide and sulphocyanide of silver. The aqueous and alcoholic solutions of this acid undergo exactly similar reac-tions at ordinary temperatures and for this reason I have hitherto failed in procuring the acid in the solid state. By rapid evaporation in the air-pump over sulphuric acid a confused semi-crystalline mass was obtained; but this gave very little hope of furnishing numbers likely to prove the exact constitution of the acid in its solid condition. P~atino-tersu~hocyanide of Barium is a deep red substance crys-tallizing in long flattened prisms or in broadlaminze often of con-siderable size. Obtained by dissolving three parts of dry platino-tersulphocyanide of potassium in the solution of one part of chloride of barium in water or as an excess of the latter is desirable it may be in the proportion of nine to four.After evaporation at a gentle heat the mass may be extracted with hot alcohol which dissolves nothing but the new salt. It does not appear to be so stable as the pot assinm-compound. Platino-tersu~hocyanideof Ammonium.-The preparation of this salt by direct union of the acid and base is difficult; that by double decomposition however is very convenient. One part of dry sul- phate of ammonia may be boiled for a few minutes in a moderately strong solution of 3.5 parts of platino-tersulphocyanide of potassium. The new salt on cooling may be separated from the sulphate of potassa and sulphate of ammonia the last of which is purposely in excess by alcohol..Another solution in hot water is requisite to obtain it pure from which the new substance is produced in beautiful crimson hexagonal plates in figure much resembling thepotassium-salt. It is quite stable at ordinary temperatures but the odour of sulpho-cyanic acid is readily perceived on boiling the aqueous solution. It gives a!l the reactions of the potassium-salt. 0.5121 grm. of substance dried in vacuo,gave 0.1150 grm. of platinum. 0.8615 , ,) burnt in oxygen and air 0.3838 , carbonic acid. I , , burnt in oxygen 0.1212 , water. clearly indicating the f ormula NH Pt 3CyS,. MR. G. 3. RUCRTON ON The theoretical and experimental numbers are Theory.Experiment. n-1 equiv. of platinum 99 34-02 34.1 7 6 , carbon 36 12.37 12-14 4 , hydrogen 4 1038 1-56 4 , nitrogen 56 19.24 -6 , sulphur 96 32.99 -291 1oo*oo Platino-tel.su~hocyanideof Sodium is best procured by precipi- tating the lead-salt with sulphate of soda. It readily crystallizes in broad garnet-coloured tables which are soluble in alcohol and in water. Platino-tersulphocyanide of Copper is precipitated by mixing solutions of sulphate of copper and platino-tersulphocyanide of po-tassium. It first appears of a brickdust-red colour which speedily changes at the boiling-heat of the liquid to a black insoluble powder. It gives a fine green solution with ammonia but thesaddition of hydrochloric acid reproduces the copper-salt of a dark brown tint.General remarks upon the foregoing compounds are perhaps better deferred until something has been said with reference to the members of another series which have arisen from the search after analogous compounds to be obtained from protochloride of platinum. I proceed therefore to the consideration of Platino- bisulphocyanide of Potassium.-Sulphocyanide of potas-sium dissolves protochloride of platinum with the production of great heat. A red liquid is formed which by gentle evaporation yields crude crystals of a substance showing in a less marked degree the cha- racteristics of the former group. As in the last case the best method for procuring it consists in acting upon the double-salt of proto- chloride of platinum and chloride of potassium (chloroplatinite of potassium*) with sulphocyanide of potassium.They may be taken in equal parts provided the latter contains no carbonate of potassa or other impurity. It is only necessary that it should be in excess. As the new salt is exceedingly soluble and crystals are not well obtained by evaporation the sulphocganide should be used as a concentrated solution and not too much of the platinum-salt added at a time so as to keep the temperature within moderate limits. A * This is ?rest obtained by neutralizing the hydrochloric solution of protochloride of platinum witti carbonate of potassa. THE PLITINO-SULPHOCYANTDES. mass of small needles is deposited on cooling which should be purified from chloride of potassium by strong alcohol from which again the salt is best recovered by spontaneous evaporation.After pressing between paper to remove excess of sulphocyanide of PO-tassiurn the salt may be once more obtained by gentle evaporation from an aqueous solution. The crystals appear in stellar groups and under the microscope show tapering six-sided prisms of a fine red colour although not so intense as is observable in the potassium-salt of the prior series. At 60' F. they readily dissolve in 24 parts of water but their solubility increases at a higher temperature and in warn1 alcohol they are soluble to any extent. They are not deliquescent neither are they when perfectly dry apparently affected by a tempe-rature of 100' C.; nevertheless for analysis it was preferred to dry them over sulphuric acid in the usual manner.Nothing worthy of remark is to be observed with reference to the method of obtaining the numerical 'details here appended. 0.0132grm of substance gave by igniting the precipitate from sul-phide of ammonium 0.3920 , platinum. The filtrate evaporated with sulphuric acid gave 0.3455 , sulphate of potash. 1-0055 , substance ignited in air and oxygen gave 0.3446 , carbonic acid. 0.7060 , substance i nited with soda-lime gave : J.g 1*2000 , chloroplatinate of ammonium. 0-5140 , substance digested with chlorate of potash and hydro- chloric acid gave 09540 , sulphate of baryta. The numbers for 100 parts give results which agree most iiearly with the formula KYtC,N2S or KPt 2 (CyS,).Theory. Experiment. \ I equiv. of potassium 39-15.38 15.27 1 , platinum 99 38.98 38.78 4 , carbon 24 9.44 9.34 2 , nitrogen 28 1 1.02 10.66 4 , sulphur 64 25.18 25.44 254 100*00 VOL. VII.-NO. xxv. n Mlt. G. B. UUCKTON ON The constitution of this salt is therefore quite in accordance with what might be expected from the modification in its construction and since 2 equivs. of sulphocyanogen are found to replace 2 equivs. of chlorine the circumstance may be employed as a distinction in its name. For the compound last-described I propose the designation p2atino-bisul3Jhocywnideof potassium and for its corresponding acid hyd;l.oplatino-bisu~ho~~unic mid which although not euphonious has the advantage of expressing the arrangement of its ele-ments.The solution of the pure salt is orange-red a port wine colour denotes impurity. It copiously precipitates silver and copper-salts the former of a pale yellow the latter of a purple-black. No visible change is produced an the nitrate of the suboxide of mercury except in giving a red tinge to the liquid; and no charac- teristic precipitates are formed with nitrate of lead or protosnlphate of iron which behaviour marks it off from the platino-tersulpho- cyanide of potassium and furnishes some good distinguishing tests. It forms a yellow heavy compound with subacetate of lead which is readily soluble in acetic and other acids. PZatino-bisuEiu~ocyaiiide of Silver was examined as a control to the formula of the potassium-salt.It is a curdy subslance not unlike sulphocyanide of silver partially soluble in ammonia with decom- position. It is soluble in sulphocyanide of potassium which solution appears to undergo the same change on dilution with water as is observable in the corresponding silver-salt of the previous series. I. 0.7114 grm. of substance dried in vamo and fused with carbo-nate of soda gave 0.4552 reduced platinum and siIver. 11. 0.9518 substance ignited in air and oxygen gas gave 0*2324 carbonic acid. 111. 1.0137 substance !gnited in air and oxygen gas gave 0.2595 carbonic acid. IV. 0.6106 substance ignited with soda-lime gave 0.8316 chloroplatinate of ammonium. 'v. 0.4454 substance gave by ignition with chlorate of potash 0.6084 sulphate of baryta.VI. 0*4?494 substance gave by ignition with chlorate of potash 0.6360 sulphate of baryta. Tli E PLAT1 NO-SULYHOCYAN IDES. Expressed in percentage composition I. 11. 111. iV. V. V1. Silver ] 63.98 --Platinum Carbon -6.89 6.98 --Nitrogen --8.53 -Sdphur --19.38 19.41 These indicate the formula Ag Pt 2(CyS,) as may be seen by comparing the results found with the theoretical requirements. Theory. Experimental -mean. 1 equiv. of silver 108 64,08 63.98 1 , platinum 99 J 4 , carbon 24 7.45 6.94 2 , nitrogen 28 8.66 8.53 4 , sulphur -64 29-81 7940 323 100*00 It is scarcely necessary to mention that the salts of both acids fom powerful detonating mixtures with chlorate of potassa.Thc platim- tersulphocyanide of silver in particular inflames with the sliglitcsL friction in a mortar accompanied with a bright flame and loud report. Care is therefore necessary in preparing a mixture for analysis by a large dilution with carbonate of soda. Hydroylatino-bisulphocyanic ac.id.-This is best procured by a cautious decomposition of the baryta salt with dilute sulphuric acid. The aqueous solution is speedily decomposed by evaporation even in vacuo during which process there is an oxidation of the sulphur at the expense of the water. A red or yellow insoluble deposit rich in platinum and hydrosulphocyanic acid are the principal bodies formed the former of which will be noticed in treating of the action of' oxidizing agents.This tendency to absorb oxygen has been slightly touched upon whilst remarking the almost spontaneous decomposition of platino-tersulphocyanide of lead into sulphate of lead and other products. Sonic knowledge has been also gained whilst searching for an c*spltlnatioiiof the frequcnt cscaye of carbonic acid attendiitg the solution of chloroplatinate of potassium in sulphocyanide of7 potassium. This effervescence has been traced to the carbonate of ptassa rnore or less present in the last salt even when crystallized from alcohol. It was also found that solutions of platino-tersulphocyanide of potassium assisted by gentIe heat react in a similar manner upon the carbonate with a partial decolorization of the liquid.A red salt crystallizes out which in 110 way differs from pIatino-bisulpbocyanide of potassium whilst the presence of both sulphate and sulphocyanide of potassium is recognized in the filtrate. The first; action seems to corisist in the partial abstraction of sulphocyanogen from the platino- toiwdphoeyanide reducing it to that of the ~ec~nd series. Part of this sulphocyanogen combines with part of the potassium. The sulphur in another equivalei-st is acted upon by the liberated oxygen forming sulphate of potassa whilst the cyanogen is left to combine with the remaining potassium. The carbonic acid escapes as such. This rather complex action may be expressed in an equation which satisfies all the requirements 6(K Pt 3CyS,)+8 (KC0,)=6(K,Pt2CyS2)+Z(KS0,) -I-5 (KCy S,) + KCy + 8CO,.A slight modification also represents the change observed in the Xibad-salt by ebullition with water. The sulphuric aeid formed by secondary action isolates the platinum acid 6 (Pb Yt 3Cy S,) + 8 H0=6 (Yb,Pt 2Cy S,) +Z (HSO,) +-5 (EICyS,) i-HCy. Long-continued boiling of the aqiieous solution of platino-tersul-phocyanide of potassium furnishes also the same result. Actiorb qf Ammonia upon the platino-sztlphocyunides,-The be-haviour of this alkali towards these compounds is interesting and differs niaterially from that shewn by bases in general or the fixed alkalies. If carbonate of ammonia be added to a cold saturated solution of ptatino-tersulphocyanide of potassium the liqaid after the lapse of a few minutes fades in colour to a pale yellow; an effer- vescence sets in; and after two or three hours a considerable quantity of yellow needles radiate in all directions.The same effect is more expeditiously obtained by using caustic ammonia; but in this case it should not be in R state of coricentration as an insoluble yellow siibstance generally contaminates the product and mnch reduces its quantity. These crystals thrown on a filter may be well washed in cold water in which they arc hut 'tittle soluble and dried without TH E PLAT1NCbP ULP H OCYA IY 11) E S . 37 heat. If required of great purity they may be again dissolved in warm alcohol which takes up more of the substance than water. The crystals obtained by this second operation however are never so large but are of a finer colour.The microscope shews them to be long rhombic prisms. Heated in a dry test-tube they are resolved into free ammonia hydrocyanic acid and with access of air sulphurous acid and metallic platinum. No trace of bisulphide of carbon could be recognized under this treatment which is a departzlre from the behaviour of the piatino-sulphocyanides in general and indicates a separation from the group. 0.4885 grm.of salt dried ile vucuo gave on ignition 02772 , platinum. 0.8092 , salt ignited with oxygen and air gave 0.1986 , carbonic acid and 01320 , water. 0,5137 , salt from another sample gave with soda-lime 1.3033 ) chloro-platinate of ammoniuni. 0.4578 , salt ignited with chlorate of potassa 0.6192 , sulphate of baryta.The formula deduced from the percentage composition is PtC H N2 52 which requires Theory. Experirnent. 1 equiv. of platinum 99 56.89 56.74 2 , carbon 12 6.89 6.69 3 hydrogen 3 1.74 1.81 2 , nitrogen 28 16.09 15.89 2 ) sulphur 32 18.39 18.55 -174 100~00 This sabstance shows therefore a departure from the general series and indicates a splitting up into compounds of a different type. An examination of the filtrate after careful addition of hydrochloric acid plainly proved that the decomposition so often noticed here again takes place. It was found to contain sulphate of potassa sulphocyanide of potassium and ammonium and cyanide of amnio-nium. The change in the molecular arrangement is expressed thus 6 (K,Pt 3 Cy S2)+ 8 NH 0= 6 (Pt C €I 2 (KSO,) N S,) i--+ 4 (KCyS2)+ 2 (NH Cy S,) i-5 (HCy S,) + HCy.The same substance is more readily formed also by substitutiug platino-bisnlphocyaiiide of potassium for platino-tersnlphocyanide. As the filtrate in this case does not contain a sulphate the action is vcry siinple Kl’t 2 Cy S +NH 0=PtC 13 N S +KCyS +IIO. A preparation was made after the latter method and ignited when it was foiind that 0*4100grm. of salt gave 0.1986 grm. of platinum. Theory requires 56.89. Experiment gave 56.68 per cent. As the probability was against the above formula truly expressing the constitution of the substance some light was anticipated by a regrouping of its elementary particles. Aii intelligible forni pre-sented itself on considering the hydrogen and part of the nitrogen as ainnionia which its behaviour at a high teniperature appeared to justify and uniting the carbon sulphur and thc rest of the nitrogen as sulphoeyanogen.Taking sulphocyanide of ammonium as the type and substituting an equivalent of platinum for onc equivalent of hydrogen we then have the su&hocynnide of ylatosnmmoniuwz (Reiset’s first platinum base). Cy S by substitution N Cy S N{ ~~ A ready proof of this supposition presented itself in the direct comparison of the tvo salts. The preparation of the latter by double decomposition is not difficult. One part of fused sulphocyanide of potassium may be dissolved in water and 1.6 parts of chloride of platosammonium added.After raising the mixture nearly to the boiling point an equal bulk of hot alcohol is shaken with the liquid to illcrease the solubility of the new substance and the whole is passed whilst hot through a filter papcr. On cooling straw-coloured needles are deposited which exhibit all the properties of the formcr compound the identity with which was still further shown by a quailtit ative analysis. 0.6120grm. by ignition gave 0.3470grrn. of platinum representing the formula PtH,NCyS,. The coinposition for 100 parts reqiiires by theory 56-80 of plat i-nuill; the quantity found was 56-69. T%€EPLATINO-SGLPHOCYANIDES. 31) Sulphocyanide of platosammonium is indifferent to the action of dilute sulphuric or hydrochloric acid. The aqueous solution docs not affect salts of copper lead or mercury but precipitates nitrate of sulphate of silver as a bulky and pale yellow compound which is rich in platinum.This precipitate requires more study than has as yet been bestowed upon it The aqueous solution by long boiling liberates ammonia and deposits the yellow insoluble substance above alluded to the composition of which is yet uncertain." Caustic potassa appears to effect the same change. A temperature between 100' and 110' C. causes the salt to fuse into a clear garnet-coloured syrup which hardens on cooling and does not appear to bc further affected by a rise to 180' C. Before dismissing this portion of the subject there appears to be yet another point of view from which the salt might be regarded.Although no doubt was entertained of the correctness of the last formula some interest seemed to be attached to the circumstance of itx polymerism with another body not hitherto prepared. I have recently had occasion to show that cyanogen gas acting on oxide of diplatosammonium produces the platinocyariide of that base the for-mula of which is double that assigned by Reiset to the decomposi- tion. The true cyanide of platosammoniurn further may be obtained from the corresponding chloride by acting with cyanide of potassium. 3ust in the same manner we might expect a parallelism between platino-bisulphocyanide of diplatosammoniuin and sulphocyanide of platosammonium. This may be more readily intelligible thus 2(Ptt€,N Cy) = PtH,N, PtCyz and 2PtH,N CyS,=PtW,N, Pt2CySz --/' -/--, i-0-J Cyanide of plato-Platinocyanide of Sulphocyanide of Platino-bisulphoq anide sammonium.diplatosammonium. platosammonium. of diplatosammonium. Plutino-bisul~hocyaPzideof ~i~lu~~~a~rno~iurn falls as a vohrninous flesh-coloured precipitate on decomposing the chloride of the base by a soluble platino-bisulphocyanide. It is quite insoluble in water and also in alcohol. Dilute hydrochloric acid dissolves it rather freely. When heated on platinum foil it liberates ammoniacal gas fuses into a black bubbling mass and then burns tinder-like to a bright platinum sponge. 0.8576 grm. of substance ignited gave 0.4896 gi m. of platinum. 97 7) , ignited in oxygen ,* 0'2090 , carbonic acid. , ignited in oxygen , 0.1460 , water.0&56 : , igriited with chlorate of , 0.1512 , platinuvn potassa and carbonate of soda . . , I 0.3617 , sulyhate of bnryta. * A well-washed sample gave on ignition as much as 92.27 per cent of platinux~. It contains sulphur and the elements of ammonia. ME. Q. B. BUCKTON OX leading to the formula PtH,N, Pt 2(CyS,). The theoretical and experimental numbers are appended. Theory. Mean found. fz equivs. of platinum 198 56.90 56.94 4 , carbon 24 6-90 6.65 6 4 , , hydrogennitrogen 6 56 1.72 16.09 1*89 - 4 , sulphur 64 18.39 18.62 c__ 343 100~00 On the action ofChlorine Gas and Nitric Acid upon the Plalino-sulphocyanides.-An examination in this direction seemed to be de- sirable from the belief that the above decomposition did not show the full extent of oxidation to which the salts of either series might be carried.When commenting upon the acids it was mentioned that their aqueous solutions were resolved by heat into a red or brown amorphous substance hydrosulphocyanic and sulphuric acids. The same brown compound is formed by pouring warm concentrated nitric acid on the powdered potassium salts Experiment also proved that if a warm and rather concentrated solution of platino-tersulpho-cyanide of poiassium be subjected to a stream of chlorine the ternpera- ture rises considerably during the absorption of the gas. By decom- position of water the chlorine passes into hydrochloric acid and the liberated oxygen converts the greater part of the sulphur into sul- phuric acid.The first of these acids may be removed by evaporation on the water-bath and the latter after careful neutralization with carbonate of soda by a thorough washing with hot water which at the same time carries off the whole of the potassa as bisulphate. During evaporation the odour of hydrocyanic acid is very percep- tible. The new substance on the filter appears of all shades of colour from a bright red to a dirty brown. It may be dried at a gentle heat and then has the form of a light non-crystalline powder strongly s:)iling the hands insoluble in water and in alcohol but before drying slightly soluble iii hydrochloric acid. It is unaffected by a solution of potassa but ammonia changes its colour to a yellow hue. When ignited in a close crucible vapours of bisulphide of carbon @aidcyanogen gas are disengaged and the solid residue consists of bisulphide of platinum.The action of concentrated nitric acid is quite similar. Hydrocyanic acid and nitrous fumes are given off and in geiieral the insoluble residue is produced of a brighter colour. THE PLATtNO-PUI.PXIOCYI\NI UES. The following iiurnbers were obtained on its analysis 0 3700 grm. of substance ignited gave 0.2304 grm of platinum. OW64 , burnt in oxygen , 0.2800 , carbonic acid. , , burnt in oxygen , 0.0320 , water. 0-7334 , burnt with soda-lime , 1.1600 , chloroplatinateof ammonium. 0.5146 , burnt with chlor. of potassa ,? 0.7048 sulphate of baryta. 1.0704 , a different sample , 0,6639 , platinum., , burnt with osygcn , 0.3426 ? carbonic acid. , , burnt with oxygen , 0.0448 , water. f regret that I have been unable to prepare this substance in such a state of purity as to place its true composition beyond all doubt. I had anticipated from its mode of forniation a substance which bears towards the platino-sulphocyanides the same relation which the so-called solid sulphocyanogen bears towards the sulphocyanides. If however we calculate the water as such it will give ail excess in the experiments of more than 3 parts in the 100 taken; and the discrepancies between the other constituents will be found as great. I am therefore inclined to suppose that the hydrogen is partly accidental and that as the formula adopted has the recommendation of great simplicity and satisfies all the conditions observed in the reaction it will ultimately prove to be correct.I have thought it better in addition to the theoretical and experimental numbers to give the ratio in parts of a unit between the component parts which places their relation in a clearer point of view. The formula of protosulphocyanide of platinum is -Ptcy s,. Theory. Found. Mean. Ratio. 1 equiv. of platinum 99 63-05 62=02 62.14 1.0 1 , carbon 12 7-64 8.53 8-72 8.62 2 3 1 , nitrogen 14 8-93 9.92 -9-92 1.1 2 , sulphur -32 20.38 18.77 -18-77 1.9 157 100*00 Hydrogen . . 0.39 0.15 0.42 0.6 99.87 There remains only to show by equation this decomposition by chlorine gas. The reaction is strictly in character with those befom noticed.K Pt 3 CyS,+ llC1+16 HO=PtCyS + 12 S0,+2 HSO, H/ + 1lIICl -t2 HCy. MR. G. H. BUCKTON ON 41.2 The platino-sulphocyanides possess characters so distinct from other salts that there is no likelihood of confounding thcni with other known compounds. They are all highly coloured and take all gra- dations from pale and bright yellow to deep red. This colour appears attendant in a great measure upon the quantity of sulphur combined with the platinum since the intensity is more remarkable in the first than iii the latter series and is nearly lost in the sulphocyanide of platosammoniuni . Their ready inflammability and peculiar odour when gently heated may also be considered as characteristic. The separation of the two series is well marked by their different action on reagents which for better illustration has been arranged in the followiiig table repre- senting the precipitation or non-precipitation of a soluble salt of each series.Reagents. Platino-t ersulphoc y anides. Plat ino-hisulyhocy anides. Subsalts of mercury . . Orange precipitate . . . No precipitate liquidchanges colonc on heating. Salts of silver . . . . . Red or orange precipitate Pale yellow precipitate. Protosalts of iron . . . . Black shining grains . . No change. Salts of copper . . . . Brick-red precipitate . . Purplish-black precipitate. Sultsalts of copper . . . Rich brown precipitate . Purplish-black precipitate. Salts of cobalt . . . . . Orange-red precipitate . No change. Salts of lead .. . . . Soluble golden lamina? . No change. Basic salts of lead . . Fine red Precipitate . . Pale yellow precipitate. Persalts of gold . . . Salmon-coloured precipi- tate . . . . . . Salmon precipitate. Ferrocyanide of potassium . Prussian blue formed on A nearly white precipitate boiling on boiling. Chromic acid . . . . No precipitate . . . . A copious reddish precipi- tate with evolution of hydrocyanic acid. Saltsof platosamine . . . Copious orange precipi-tate . . . . . Fine yellow precipitate. Salts of diplatosamine . . Fine vermilion-red preci- pitate. . . . . . Flesh-c'oloured precipitate. The ready conversion of the sulphur in these compounds into sulphuric acid in presence of water is shown in an interesting manner by their action upon metallic zinc.Aqueous solutions of the potassa salt are resolved into platinuin black hydrosulphocyanic acid sulphate of potassa and free sulphuric acid which acting upon the zinc liberates a considerable quantity of hydrogen gas. A few general remarks upon the constitution of the platino-sulpho- cyanides may not be considered here misplaced. Viewing then) ac- curding to Berzelius's explanation of the ferrocyanides they must THE PLATINO-SULPHOCYANIDES. be taken as double compounds of protosutphocyanide and bisulpho- cyanides of platinum with a metallic sulphocyanide or hydrosulpho-cyanic acid; Platino-cyanides. Platino-bisulphocyanides. Platino-tersulphocyanides. ---.c-__-I ' -.-./ M CyCPt Cy M Cy S,+Pt Cy S M Cy S,+Pt 2 Cy S whilst on the more generally received idea they contain two separate radicals of acid character forming salts upon the hydrochloric acid type.The similarity of action between sulphur oxygen chlorine cyanogen &c. in combination has been frequently remarked. In-stances of substitution of sulphur for chlorine may be seen in the reactions of sulphide of potassium upon hydrochloric ether and Dutch liquid. Throughout this Paper I have assumed the existence of chloro-platinous and chloroplatinic acids from the close similarity they bear towards the platino-sulphocyanides; and I think an argu-ment in favour of their existence may be found in the construction of the latter from the former by simple substitution of sulphocyanogen for chlorine. In the same nianiier we construct the platino-cyanides bp exchanging chlorine for cyanogen although at present we want the higher number in the series.This will doubtless turn up upon a careful search. We have thus Platitto-chlorides or Platino-Platino-sulpho-chloro-platinides. cyanides. cyanides. -' LyrJ -M Pt C1 missing M Pt 3 Cy S M Pt Cl M Pt Cy M Pt 2Cy S Some interest attaches to the new acids from the large number of sulphur-atoms they contain. Platino-tersulphocyanide of potassium presents I believe the first instance of the union of sulphur with the triple cyanogen group represented by the cyanurates in which all the oxygen is replaced by sulphur. The analogy is not however strict between them since it will be seen that in the new compounds only 2 equivs.of hydrogen are replaced by metals. The same objection does not apply with reference to the fulminates. In conclusion notice should be taken of a crystalline compound described by Claus which is prepared by acting upon bisulpho-cyanide of mercury with sulphocyanide of potassium. From the for- mula given which is K Cy S + 2€IgCy S, it is clearly a double coni-pound and therefore has but little rcsemblance or conuection with the substances above described.