ON THE CO3fPOSITION OF WHEAT-GRAIN &C. K-On a new Series of Organo-Thionic Acids. BY JOHNTHOMAS HOBSON DALTON SCHOLAR IH THE LABORATORY OF OWEN’S COLLEGE MANCHESTER. THEresearches of Dr. Franklxndt have shown that thereexists a class of bodies containing metals in combination with the alcohol radicals and to which he has given the name of “organo metallic bodies.” One of the peculiar features possessed by these com-pounds is that they bear a very strong molecular analogy to the inorganic compounds of the metal they contain which inorganic compounds may therefore be regarded as the types of their organic derivatives. Thus antimony which with hydrogen forms anti-moniuretted hydrogen SbH, and with oxygen teroxide of antimony SbO, gives with ethyl stibethyl Sb(C1,H5)3; and arsenic which * These estimates have reference to the bread from rather fine flour ;that from the coarser flours contains rather more of nitrogenous matters.f-Chem. SOC.Qu. J. vi. 57 andPhil. Trans. 1852,p. 417. 56 HOBSON dth the inorganic elements sulphur and hydrogen gives arseiiiu.. Petted hydrogen ASH, and bisulphide of arsenic ASS, forms with methyl cacodyl As (C2H3),; and with ethyl ethylic cacodyl As(C,H,),. Cacodyl also unites with oxygen forming oxide of ca- codyl As {(‘bH3)2} resembling arsenious acid AsO ; and caco- ilylic acid agreeing with arsenic acid. From the recentresearches of Wohler Hofmann and Cahours it appears that this singularity of behaviour is not exclusively confined to the combinations of metals with the alcohol radicals but that the metalloids selenium and phosphorus form with these radicals compounds molecularly similar to their inorganic types and possessing for the most part the property of uniting directly with oxygen.Thus selenethyl forms with oxygen oxide of selenethyl Se {‘hH5} which is mole- cularly homogeneous with selenious acid SeO, whilst phosphorus with ethyl gives phosphethyl P(C,H,) corresponding with phosphorus acid PO,. Considering the strong analogy existing between sulphur and selenium I was induced to try whether thc sulphide of ethyl would not like selen-ethyl unite with oxyb wen to form compounds of the thionic acid type. In preparing sulphide of ethyl for this purpose I tried several of the methods usually recommended but found most of them to yield only a very poor product.By passing chloride of ethyl into an alcoholic solution of protosulphide of potassium I obtained only traces of the compound ; and the distillation of dry protosulphide of potassium with sulphovinate of potash yielded scarcely a better result. The following method however gave a satisfactory pro-duct :-An alcoholic solution of protosulphide of potassium was made by saturating a weighed quantity of caustic potash dissolved in alcohol with sulphuretted hydrogen and adding to this the same weight of alkali as that previously used. This alcoholic solution of protosulphide of potassium on distillation with sul- phovinate of potash yielded a large quantity of sulphide of ethyl.The sulphide of ethyl thus prepared was treated with dilute nitric acid. On the application of a gcntle heat dense nitrous fumes were given off the sulphide of ethyl entirely disappearing When all action had ceased the liquid which contained an excess of nitric acid was evaporated for some time in a water bath to expel as much as possible of this acid ; it was tlicii saturated with carbonate of baryta arid tlic evaporation contitiucd to dryness. The dried mass being afterwards treated with alcohol aitd filtered ON ORGANO-TIIIONIC ACIDS. from the nitrate of bxryta the filtrate on long exposure to the heat of a water-bath yielded a small quantity of a thick syrupy liquid which contained sulphixr ethyl and baryta but showed no disposition to crystallize and could not be obtained in a satisfactory state for analysis.This experiment showed however that an acid had been formed which most probably contained sulphur ethyl and oxygen; but finding that this acid was obtained in such small quantities from sulphide of ethyl I abandoned this process of forming it. The recent researches of Dr. Frankland on the substitution of oxygen by an alcohol-radiciil in the case of binoxide of nitrogen,* led me to hope that a corresponding reaction with an oxygen compound of sulphur and one of the organo-zinc compounds would produce the desired substitution. For obvious reasons I selected for this reaction sulphurous acid and zinc-ethyl ; and a preliminary experiment showed that these bodies act upon each other very energetically forming a whitc crystalline mass which mas evidently the zinc-salt of a thioriic acid.On a large scale the process was conducted as follows :-A quantity of zinc-ethyl prepared according to the plan recommended by Dr. Frankland,? was placed in a flask and sulphurous acid evolved from sulphuric acid and copper turnings and dried by passing through a Woulfe’s bottle containing concentrated sulphuric acid was allowed to come in contact with it. The gas was very rapidly absorbed by the zinc-ethyl and so much heat was produced that it was found necessary carefully to cool the flask during the whole process of absorption. In a short time a white crystalline body was formed in the zinc-ethyl and gradually the whole contents of the flask were converted into a mass of minute crystals which pro- tected some of the zinc-ethyl from contact with the sulphurous acid; so that unless the action of the gas was very prolonged and the crystalline mass broken up the latter effervesced with water owing to the presence of undecomposed zinc-ethyl.After purifi- cation and crystallization first from alcohol and then from water it yielded on analysis the following numbers :-I. 6.02 grs. burnt with oxide of copper a tube of peroxide of lead being interposed between the chloride of calcium tube and potash apparatus gave 3-20grs. of carbonic acid and 1.91 grs. of water. * Proceedings of the Royal dociety viii. 198. + Phil. Trans. 1855 p. 259. 58 HOBSON 11. 6-28grs. similarly treated gave 3.35 grs.of carbonic acid and 2.16 grs. of water. 111. 6.155 grs. gave 3.25 grs. of carbonic acid and 2.065 grs. of water. IV. 12.30 grs. dissolved in water and precipitated boiling by a solution of carbonate of soda the precipitated basic carbonate of zinc washed dried and ignited gave 2.995 grs. of' oxide of zinc. IT. 5.96 grs. cautiously ignited then treated with nitric acid and afterwards strongly heated and exposed to a current of air gave 1.46 grs. of oxide of zinc. VI. 3-80 grs. ignited with a mixture of clilorate of potash and carbonate of magnesia thc product clissolvcd in hydrochloric acid and precipitated with chloride of barium gave 7.82 grs. of sul-phate of baryta. VIT. 3-14 grs. similarly treated gave 6-67 grs.of sulphate of barg ta. These results as is seen from tlie following comparison agree with tlie formula :-Calculated. Analyses. Mean. 1 234567 C. . 24 14.41. 14.49 14.54 14.40 -* -14.48 HG . . 6 3-80 3'52 3-02 3.72 --3-69 --19.53 19.62 -19-57 Zn . . 32.5 19.52 S . . 48 28.82 ---28.23 29.15 28.69 0; . . 56 33'65 -_---33.57 -___ 166.5 1G0-00 100*00 This compound is thereforc the ziuc-salt of a new acid formed by the substitution of one equivalent of oxygen in three equiva- lents of sulphiirous acid by ethyl. This acid I propose to call Ethylotrithionic Acid. Ethylotrithionate of zinc presents the appearance of minute acicular crystals which are colourless and lime a peculiar odour ; they are almost insoluble in cold but moderately soluble in boiling alcohol.It dissolves sparingly both in hot and cold water and also in ether; on evaporating its aqueous solution the salt crystal- lizes out as a pellicle which floats on the surface. Ethylotrithio-nate of zinc possesses a peculiar and somewhat bitter taste. It contains one atom of water of crystallization which it retains at loo0 cr. ON ORGANO-THIONIC ACIDS. The crude salt produced by the action of zinc-ethyl on sulphu- rous acid had not however such a simple constitution as the zinc-salt mentioned above since owing to the presence of an excess of oxide of zinc derived from the action of water on the undecomposed zinc-ethyl a basic salt had been formed. This salt submitted to analysis yielded the following results :-I.5.42 grs. burnt with oxide of copper yielded 2.47 grs. of carbonic acid and 1-76grs. of water. 11. 10.50 grs. dissolved in boiling water and precipitated with a solution of carbonate of soda the precipitated basic carbonate of zinc mashed dried and ignited gave 3.305 grs. of oxide of zinc. 111. 4.63 grs. ignited with a mixture of chlorate of potash and carbonate of magnesia the product dissolved in hydrochloric acid and precipitated with chloride of barium yielded 8.37 grs. of sulphate of baryta. The following calculation shows that these numbers agree with thc formula :-Calculated. Analyses. 1 2 3 A /-\ -C . . 48 12-55 12-43 --Isl3. . 13 3.39 3.61 -Zn . . 97-5 25.49 -25-25 -s6 96 25-09 -24-80 I O, .. 128 33-48 --382.5 100.00 Ethylotrithionate of Baryta BaO,S C4H5 I-+ 1x0. -This 05 salt is prepared by adding to a boiling solution of the zinc salt caustic baryta in excess and then passing carbonic acid through it till the excess of base is precipitated. It crystallizes on cooling fi*omits concentrated solution in water in the form of a pellicle mhich floats on the surface. It isa colourless salt which does not decompose when heated to 170° C; it contains one atom of water of crystallization which is driven off at 100' C. Ethylotrithionate of baryta exposed for some time over sulplzuric acid in vacuo yielded the following analytical results. I. 7*52grs. burnt with a mixture of chromate of lead and oxide of copper gave 3.34grs. of carbonic acid and 2-05 grs.of water. 60 HOBSON 11. 4.235 grs. dissolved in water and the baryta precipitated with dilute sulphixric acid gave 2-40grs. of sulphate of baryta. 111. 6.35 grs. ignited with carbonate of magnesia and chlorate of potash the product dissolved in hydrochloric acid and precipi- tated with chloride of barium gave 10.835 grs of sulphate of baryta. These results correspond closely with the above formula. Calculated. Analyses. 1 2 3 -c * . 24 11*84 12-11 --TI . . 6 2.96 3.03 -Ra . . 68.6 33.86 -33.33 - 48 23-68 -23.41 S . -0 . . 56 27.66 -202.6 100.00 Bthylotrithionic Acid.-HO,S { 'hr5 } -To prepare this acid in its free state a quantity of its zinc-salt was distilled with dilute sirlphuric acid. The thermometer during the distillation stood fixedly at 140' C and a liquid passed into the receiver which reddened litmus strongly but contained the acid in a very dilute form.In the hope of obtaining it in a more concentrated state the zinc-salt was distilled with strong sulphiiric acid; but this iiiethod did not succeed as the thionic acid was entirely decom- posed thc mass in the retort being charred and large quantities of sulphurous acid evolved whilst an oily liquid with an alliaceous odour distilled over. Finding howcv-er that neither of these methods was adapted for obtaining large quantities of the free acid I exactly precipitated the baryta from ethylotrithionate of baryta by dilute sulphuric acid separated the sulphate of baryta by filtration and thus obtained a moderately concentrated solution in water.A quantity of this aqueous solution was subjected to prolonged evaporation in a water bath but the acid could not be obtained by this method in its monohydrated state ; since after very lengthened evaporation it still retained five equivalents of water. To determine however whether the acid retained its original constitution a baryta-salt was formed by dissolving in it a quantity of carbonate of baryta. The salt thus obtained on being recrystallized from water and dricd at 100' C gave 011 analysis the following numbers which ON OIXGANO-TECTONIC ACIDS. agree with the formula of the anhydrous baryta-salt of ethylo-trithionic acid 1. 8.54 grs. burnt with chromate of lead gave 3.79 grs.of carbonic acid and 1.825 grs. of water. 11. 447 grs. burnt with oxide of copper gave 1,975 grs. of carbonic acid and 1-00grs. of water. 111. 9.30 grs. dissolved in water and precipitated with dilute sulphuric acid gave 5.44 grs. of sulphate of baryta. IV. 4-43 grs. ignited with chlorate of potash and magncsia the product dissolved in hydrochloric acid and precipitated with chlo- ride of barium gave 7-82 grs. of sulphate of baryta. -Calculated. Analyses Mean. 1 2 3 4 C,. 24 12.39 12-10 12-05 - - 12-08 Ba H . 68.6 . 5 35-43 258 -2.37 -2.48 3 B.41 - - 2.43 34.41 S,. . 48 24-79 - - - 24-22 2 4.22 0 . 48 2481 - - - - 26.86 193-6 100*00 100*00 Ethylotrithionate of Silver.-AgO,S {'by5}-This salt was obtained by dissolving carbonate of silver in the free acid prepared as above.It is very stable neither evaporation in a water-bath nor exposure to light decomposing it in the slightest degree. The ethylotrithionate of silver is a white crystalline body very soluble in water; on exposure to the air it rapidly attracts moisture becoming liquid. It will bear heating to 100"C but if the tem- perature be raised much above this it is entirely decomposed. This salt after being dried over sulphuric acid in vacuo yielded the following analytical results :-I. 9-42 grs. burnt with oxide of copper gave 3.52 grs. of car-bonic acid and 1.882 grs. of water. 11. 8-30 grs. similarly treated gave 3-15 grs. of carbonic acid and 1.66 grs. of water. 111. 10.75 grs. gave 4.005 grs.of carbonic acid and 2.17 grs. of water. IV. 3-60 grs. cautiously ignited and exposed to a stream of air gave 1.665 grs. of metallic silver. V. 5.92 grs. similarly treated gave 2.73 grs. of silver. VI. 11.40 grs. dissolved in water and precipitated with hydro- chloric acid gave 6.995 grs. of chloride of silver. 62 ROBSON T'II. 5.27 grs. ignitcd with a mixture of chlorate of potash and carbonate of magnesia the product dissolved iii hydrochloric acid and precipitated with chloride of barium gave 7-87 grs. of sul- pirate of baryta. The following comparison shows that thesc nurnbei s agrce with the above formula :-Calculated. Analyses. Mean 1 2 3 4567 P C . 24 10.30 10.20 10.35 10.16 --10.24 H5 . 5 2.15 2-22 2.22 2-24 --2-23 Ag .108 46.35 --46.25 46.11 46-18 -46.18 S . 48 20'60 ----20-49 20.49 0 . 48 20.60 ---20.86 233 100.00 100-00 Ethylotrithionate of Copper. -'6;.{CuO,S,-}-This salt can be prepared either by the double decomposition of the baryta-salt or by dissolving carbonate of copper in the free acid. It crystal-lizes both from its aqueous and alcoholic solution in the form of greenish blue needles which are deliquescent. When dried at 100' C it gnve on analysis the following results :-I. 6.55 grs. burnt with oxide of copper gave 3.64 grs. of car-bonic acid and 1.96 grs. d' water. 11. 5.85 grs. similarly treated gave 3-26grs. of carbonic acid and 1.725 grs. of water. 111. 4.27 grs. cautiously ignited and exposed to a stream of air gave 1.08 grs.of oxide of copper. IV. 3-21 grs. ignited with a mixture of chlorate of potash and carbonate of ningneais the prodrict dissolved in hydrochloric acid and precipitated with c!doride of barium yielded '7.065 grs. of sul-yhte of barpta. These numbers agree with tlie formula above given as will be seen from the follomirig cnlculation :--Calculated. 1 Analyses. 2 3 4 Mean. C,. . 24 15-33 15-15 15.20 - - 15.18 13 . 5 3.19 3.32 3.27 - - 3$29 Cu s 0 -31% 48 48 20.18 30.65 30.65 -_ - -- 20.18 - -30.20 - 20.18 30.20 31.15 156.6 100.00 100~00 ON ORGANO-THTONIC ACIDS. Ethylotrithionic Ether.-C,H,O S {'6:5} -This ether was obtained by distilling a mixture of crystallized etliylotrithionate of baryta with sulphovinate of potash. On applying the heat of an oil bath the crude ether came over which after being washed dried by standing over chloride of calcium arid redistilled yre- sented the appearance of' an oily yellow liquid slightly heavier than water and possessing a disagreeable smell.It is insoluble in water but miscible with alcohol in all proportions. Unfortunately I did not obtain a sufiicient quantity of the ether to admit of the determination of its specific gravity and boiling point. Ethylotrithionic ether after being thoroughly dried by chloride of calcium yielded the following analytical results :-I. 3.72 grs. burnt with oxide of copper gave 4.22 grs. of car-bonic acid and 2-21grs. of water. 11. 2.43 grs. burnt with magnesia and chlorate of potash the product dissolved in hydrochloric acid and precipitated with chlo- ride of barium gave 5.50 grs.of sulphate of baryta. The followiiig calculatioii agrees with the above formula :-Calculated. Analyses. 1 2 -C . 48 31.17 30.93 -HI(). 10 6.49 6-60 S . 48 31.17 -31.05 0 . 48 31.17 -154 100*00 Ethylotriti~ionateof Soda.-NaO,S c4H5I-+ 130. -This (05 salt was also prepared by dissolving carbonate of soda in the free acid evaporating to dryness and treating with alcohol which dissolves the ethylotrithionate of soda whilst the excess of carbonate remains insoluble. The alcoholic solution on evaporation in vacuo over sulphuric acid yielded colourless crystals in the form of needles which were however very small and not well defined. Deter-minations of the sulphur and sodium contained in this salt after being thoroughly dried in vacuo gave the following results :-I.8-40 grs. evaporated to dryness with sulpl-ruric acid and ignited gave 3-94grs. of sulpliate of soda. 11. 4-52 grs. burnt with a mixture of chlorate of potash and magnesia the prorluct clissolvd in hydrochloric acid and precipi- 64 HOBSON ON ORGANO-TIIIONIC ACIDS. tated with chloride of barium gave 9.90 grs. of sulphate of baryta. These numbers agree sufficiently with the above formula. C'alculated. Analyses. 1 2 1 Na . 23 14-65 15.21 -S . 48 30.57 -30.05 Sulphurous acid is also rapidly absorbed by zinc-methyl a white crystalline body being produced as in the case of zinc-ethyl. I reserve however for a future communication the complete history of this body which contains most probably the zinc-salt of the first acid of this series-viz.the Methylotrithionic Acid. It is also highly probable that a complete series of org;mo-thionic acids will be produced by acting upon sulphurous acid with the various zinc-compounds of the alcohol-radicals. The following is a list of the names and formulz of the bodies which have been described in this memoir :-Ethylotrithionic Acid. -HO,S3 { '6:5} Ethylotrithionate of Zinc. -ZnO,S { 0 } C4N5 + II0. Basic ethylotritliionate of Zinc.-2(ZnO,S,{'b;s) + HO) t Zn0,Ilo. Ethylotrithionate of Baryta.-BaO,S { C4H5 0 } + Ho* Ethylotrithionate of Baryta dried at 100' C.-BaO,S Ethylotrithionate of Silver.-AgO,S Et,hylotrithionate of Copper.-CuO,S '(f5} { Ethylotrithionate of oxide of Ethyl.-C,H,O,S {C$5) Ethylot rithionat c of Soda.-NaO S