NOTICES OF PAPERS CONTAINED IN OTHER JOURNALS. On a new series of Organic Bodies containing Metale. By Dr. E. Frankland. (From the '' Philosophical Transactions," abstracted by the Author.) Under the above title I described more than three years ago some preliminary experiments," which proved the existence of certain organic compounds highly analogous to cacodyl and like that body consisting of a metal or in some cases of phosphorus associated with the groups C31& C4H5 &C. and possessing in some instances highly remarkable powers of combination. I fixed the composition and studied some of the reactions of two of these bodies to which the names zinc-methyl (C 13 Zn) and zinc-ethyl (C 13 Zn) were provisionally assigned besides giving methods for procuring similar compounds containing tin arsenic and phosphorus by acting upon the iodides of the alcohol-radicals with these elements and expressing a belief founded upon the similarity of functions existing between hydrogen and the groups of the form C &,+I) that most if not the whole of the compounds contained in the following series might be formed those marked thus * being at that time already known.Hydrogenseries. Butylseries. Valylseries. series.Amyl I series.Phenyl Zn H As €I,* Sb H3* P H,* More recently Lowig and Schweit zer? have commenced labour- * Ann. Ch. Pharm. LXXI 213; Chem. SOC. Qu. J. 11 297. -f Ann. Ch. Pharm. LYXV 315. DR. E. FRANKLSND ON A NEW SERIES OF ing in the same field and have filled up one of the gaps in the foregoing table by the foririation of stibethyl Sb (C H5)3 by acting UPGU iodide of ethyl with an alloy of antimony and potassium.The same chemists state also the probable formation of siinilar com-pounds contaiuing methyl and ainyl in the place of ethyl and bismuth and phosphorus instead of antimony. The agents which I have employed in the formation of these organo-metallic bodies are two-viz. heat and light ;in many cases either of these can be used in others only one can be made to effect the desired combination whilst more rarely the assistance of both appears to be essential. In those experiments in which heat was employed the materials were subjected to its action in sealed glass tubes about 12 inches long and varying in diameter from 4 inch to 1inch the thickness of the glass being about + inch.To preserve the gaseous products of the operation in a state of perfect purity for subsequent investigation the tubes were well exhausted before being sealed; they were then immersed to about half their depth in an oil- batb and heated to the required temperature. In cases where the influence of light was employed the materials confined in tubes of precisely similar dimensions were exposed to the sun's rays concen- trated in most instances by an 18-inch parabolic reflector near the focus of which the tubes were placed either naked or surrounded by a solution of sulphate of copper to absorb the calorific rays. By this arrangement the light and heat could be increased diminished or modified at pleasure which was found very convenient in several of the operations.ACTION OF TIN UPON IODIDE OF ETHYL. When iodide of ethyl and metallic tin are exposed to the action of either heat or light the tin gradually dissolves in the ethereal liquid which finally solidifies to a mass of nearly colourless crystals. This reaction is effected most conveniently by the action of light an excess of tin-foil cut into narrow strips being employed. The sealed tubes containing these ingredients should be placed near the focus of a large parabolic reflector the temperature being prevented if neces-sary from rising too high by immersing them in water or in a solution of sulphate of copper The unconcentrated rays of the sun or even diffused daylight are quite sufficient to determine the formation of the crystalline body; but an exposure of several weeks or even months would be necessary for the completion of the change which is effected by the use of the reflector in a few days of bright sunshine.The liquid gradually assumes a straw-yellow colour but its solidification is prevented as long as possible at the close of the operation by allowing the temperature to rise to 35O or 40' C. ; thus ncarly the wholc. of the iodidc of cthyl bcconws ORGANIC BODIES CONTAINING METALS. united with tin. When heat instead of light is employed to effcct the combination the tubes should not he more than 4 inch in diameter and to avoid the risk of explosion should only be one-fourth filled with the materials the combination takes place at about 180' C.The agency of heat is therefore much less convenient than that of light in the production of this reaction which is also never so complete as when the latter agent is employed. I have however satisfied myself that the results are the same in both cases. I. Exurnination of Solid Products.-The capillary extremities of the tubes in which the foregoing reaction has taken place were broken off under sulphuretted water and beneath a jar filled with the same liquid :* the gases evolved were preserved for eudiometrical investi- gation. The crystalline product was then withdrawn from the tubes and after being exposed to a gentle heat for a few minutes to expel the iodide of ethyl that had escaped Combination was treated with alcohol in which the crystals readily dissolved leaving only a small residue of a bright red colour which proved to be protoiodide of tin.The filtered alcoholic solution was then placed over sulphuric acid in vacuo where it soon deposited a large crop of long needle- like crystals which when freed from the mother-liquor washed with a small quantity of dilute alcohol dried between folds of bibulous- paper and finally over sulphuric acid in zlacuo yielded analytical results corresponding closely with the formula C H Sn I. This body is therefore the iodide of a new organo-metallic radical for which I propose the name STANETHYLIUM Iodide of Stanethykium crystallizes in transparent slightly straw- coloured needles which are right-rectangular prisms frequently & inch broad and 2 or 3 inches in length.They are very soluble in ether and in boiling alcohol less so in cold alcohol and in water; the watery solution is decomposed on boiling oxide of stanethylium being precipitated and hydriodic acid formed. Iodide of stanethy- lium fuses at 42O C. and boils at 240' C. undergoing at the same time partial decomposition ;it possesses at common temperatures a peculiar pungent odour somewhat resembling the volatile oil of mustard and which irritates the eyes and lining membrane of the nose causing a discharge which continues for several hours or even days especially if the vapour from the heated iodide of stanethylium be inhaled; yet this compound can scarcely be said to be volatile at common temperatures since a few gTains may be exposed to the air for several weeks without any appreciable loss of weight.Oxide of StanethyZium.-In contact with solutions of the alkalies iodide of stanethylium is immediately decomposed oxide of stan-ethylium and an alkaline iodide being formed * Chem. SOC. Qn. J. 11 267. DR. E. FRANKLAND ON A NEW SERIES OF c H sn I } = { c €€; Sll 0. KO KI. With solutions of potash and soda the oxide of staiiethyliuiii dissolves in an excess of the precipitant but is reprecipitated unchanged by cautious neutralization. The precipitated oxide is almost completely insoluble in an excess of amiiionia. A quantity of the oxide of stanethylium prepared by precipitation with an excess of ammonia and submitted to analysis yielded results agreeing with the above formula.Oxide of stanethylium presents the appearance of a somewhat cream-white amorphous powder closely resembling peroxide of tin but less heavy than that oxide; it has a peculiar though slight ethereal odour and a bitter taste ; it is insoluble in water alcohol and ether but readily dissolves in solutions of the acids and of the fixed alkalies; with acids it forms salts which are however for the most part difficultly crystallizable ; those with strong acids exhibit an acid reaction. The nitrate deflagrates when heated to about 120' C. and on the application of a hlgher heat becomes pure peroxide of tin. The salts of the oxide of stanethylium behave with reagents so nearly like the salts of peroxide of tin that the two are very difficult to distinguish from each other.Sulphide of StanethyZiurn.-When sulphuretted hydrogen is passed through an acid solution of a salt of stanethylium a cream-culoured precipitate falls which is insoluble in dilute acids and ammonia but soluble in concentrated hydrochloric acid solutions of the fixed alkalies and alkaline sulphides; from its solutions in the fixed alkalies and alkaline sulphides it is reprecipitated unchanged on the addition of an acid. Its formula is C H5Sn S and it is produced by the following reaction C4H,SnO) = {C,H,SnS HS HO. Sulphide of stanethylium presents the appearance of an aniorphous cream-coloured powder having a pungent and very nauseous smell resembling that of decaying horseradish ; when heated I't fuses froths up and decomposes cmitting vapours of a most insupportable odour.Heated with nitric acid it is decomposed with the forniation of peroxide of tin. Chloride of Stanethylium C H Sn C1.-This salt is best pre-pared by dissolving oxide of stanethylium in dilute hydrochloric acid; on evaporation at a gentle heat or over sulphuric acid in cacuo the chloride crystallizes out in long colourless needles isomorphous with the iodide which salt it also closely rescniblea in all its proper- ties; it is however more volatile and therefore emits a niore intensely pungent and irritating odour than the iodide. Stanethyliurn.-TVhcii a strip of' zinc is inimcrscd in a solution 01' ORGANIC l3OI)IES CONTAINING METALS.a salt of stanethylium (a solution of the chloride of stanethylium is the best for this purpose) it speedily becomes covered with denw oily drops of a yellow colour which finally separate from the lower extremity of the zinc and accumulate at the bottom of the vessel; the formation of the oily liquid is much favoured by gentle heat. The yellow oil well washed with water dried over chloride of calcium and submitted to analysis yielded results agreeing with the formilla C 1-15Sn and showing that stanethylium is formed by the following sirnule reaction C,H,SnCl} -(C,H5Sn -Zn zn c1. Stanethylium is a thick heavy oily liquid of a yellow or brownish-yellow colour and an exceedingly pungent odour resem-bling that of its compounds but much more powerful.It is inso-luble in water but soluble in alcohol and ether. At about 150' C. it enters into ebullition a quantity of metallic tin is deposited and a colourless liquid distils over having a peculiar odour containing a considerable quantity of tin and exhibiting no tendency to combine with iodine or bromine. I have not yet further examined this liquid; but it possibly consists of or contains binethide of tin Sn (C H5)?. In contact with air stanethyliuni rapidly attracts oxygen and is converted into a white powder which has all the properties of oxide of stanethylium. Chloride iodide and bromide of stanethyliuni are instantaneously formed by the action of chlorine iodine and bromine or their hydrogen acids respectively upon atanethylium ; the two first are in every respect identical with the salts above described and the bromide which closely resembles them yielded analytical results in harmony with the formula C H Sn Br.Thus stanethylium perfectly resembles cacodyl in its reactions combining directly with the electro-negative elements and regenerat- ing the compounds from which it has been derived. 11. Examination of Gaseous Products.-The examination of the gases evolved on opening the tubes in which iodide of ethyl and tin had been exposed to the action of heat or light showed that they consisted of hydride of ethyl and olefiant gast in proportions indicated by the following percentage numbers I. and 11. 111. I-lydride of Ethyl. Olefiant gas . Nitrogen .. . . 81-61 16.82 1-57 81*43 17.28 1.29- c-- 100~00 100~00 The presence of hydride of ethyl aud olefiant gas amongst the UR. E. FRANKLAND ON A NEW SERIES OF products of the action of heat or light upon iodide of ethyl and tin shows that the direct combination of these latter bodies is not the only reaction which takes place but that a portion of the iodide of ethyl is also decomposed by the tin with the production of iodide of tin and ethyl the latter body being transformed at the moment of its liberation into hydride of ethyl and olefiant gas a catalysis to which this radical is so prone. The large excess of hydride of ethyl exhibited in the above analy- tical results may have been caused either by the greater solubility of olefiant gas in iodide of ethyl (a further and considerable amount of gas being expelled from the tubes by a gentle heat) or by the presence of moisture in the materials which would give rise to the formation of oxyiodide of tin and hydride of ethyl.C,H I C H I€ H50\ = ./ ftsn J [SnO+SnI. Both these causes probably contributed to produce the excess of hydride of ethyl; but the very small amount of gaseous products compared with the solid ones shows that the production of the former is only an accidental circumstance which however it may be interpreted does not at all affect the principal reaction-viz. the formation of iodide of stanethylium. STANMETHYLIUM are formed when the iodides and STANANYLIURI of methyl and amyl respectively are exposed to the action of light in contact with tin.Their salts are isornorphous with those of stan-ethyliuni; but I have not completed the investigation of these bodies. ACTION OF ZINC UPON IODIDE OF METHYL. When iodide of methyl and zinc are exposed to a temperature of about 150' C. in a sealed tube the zinc gradually dissolves with the evolution of gas whilst a mass of white crystals and a colourless mobile liquid occupy after a few hours the place of the original materials. The gas evolved on breaking off the capillary extremity of the previously exhausted tube was collected and preserved over sulphuretted water. I will refer to this gas again under the name of a. On cutting off the upper portion of the tube and pouring cold distilled water upon the mobile liquid and white mass of crystals just mentioned a very violent action ensued and a column of flame ORGANIC BODIES CONTAINJNG METALS.several feet high shot up momentarily from the mouth of the tube; but the action soon became more moderate and a cork and gas- delivering tube being fitted into the decomposition-tube the gas was collected and preserved. I will call this second gas p. Zr NCAlETHYLIUM.-FrOm a preliminary experiment it was ascer-tained that the gas evolved on opening the decomposition-tube possessed before contact with water a most insupportable and very peculiar odour arid that when ignited it burnt with a greenish-blue flame producing dense white fumes; when a porcelain plate was held in this flame it immediately became coated with a jet-black deposit surrounded with a white ring! this black deposit dissolved in dilute hydrochloric acid with evolution of hydrogen gas and the solution was found to contain chloride of zinc.Hence it was evident that a gaseous or volatile compound of zinc was present amongst the products of decomposition and this was soon found to reside in the mobile liquid above mentioned; for on inverting the tube and allowing a few drops of the liquid to escape it inflamed sponta-neously the instant it came in contact with the air and produced by its combustion large quantities of oxide of zinc. In order to obtain this liquid in a state of purity another tube was charged with iodide of inethyl and excess of zinc and subjected to a heat of 350' to 160' C.until every trace of iodide of methyl was decomposed. The drawn-out extremity of the tube being broken off the included gas was allowed to escape and the liquid contents were then separated from the solid ones by distillation at a gentle heat in an atmosphere of dry hydrogen. The analytical operations upon this liquid proved it to be a new radical for which zincmethyliuin (C H Zn) will be a convenient name and that it is forined by the following reaction Zincmethylium is a colourless transparent and very mobile liquid ref;.acting light strongly and possessing a peculiar penetrating and insupportable odour; it is very volatile but I have not yet been r:ble to determine its boiling-point with accuracy. Zincmethylium corn- bines directly with oxygen chlorine iodine &c.forming somewhat unstable compounds a description of which I reserve for a future communication. Its affinity for oxygen is even more intense than that of potassium ;in contact with atmospheric air it instantaneously ignites burning with a beautiful greenish-blue flame and forming white clouds of oxide of zinc; in contact with pure oxygen it burns with explosion and the presence of a small quantity of its vapour in combustible gases gives them the property of spontaneous inflamma- bility in oxygen. Thrown into water ziricmethyliuni decomposes that liquid with explosive violence and with the evolution of heat and liTht; when the action is moderated the sole products of the decomposition are oxide of zinc and hydride of methyl.The extraordinary affinity of zincmethylium for oxygen and electro-negative elements in general its peculiar composition and the facility with which it can be procured cannot fail to cause its employ- ment for a great variety of transformations in organic compounds. By its agency there is every probability that we shall be able to replace oxygen chlorine &c. atom for atom by methyl and thus produce an entirely new series of organic compounds and obtain clearer views of the constitution of others. I intend to pursue this branch of the subject whilst studying the compounds of zincmethyl- ium and the corresponding bodies containing ethyl and amyl. An examination of the gas a proved it to consist of equal volumes of methyl (C HJ and hydride of methyl (C H3 €1) no trace of the first term of the olefiant gas series (C H,) was present although tlie analogous decomposition of the iodides of ethyl and amyl by zinc,* led me to search very carefully for it.The occurrence of methyl amongst the products of the decomposition shows that a portion of the iodide of methyl is decomposed according to the following equation The origin of the hydride of methyl is readily perceived when the volatility of zincrnethylium and the method of collecting the gas are taken into consideration. On opening the decomposition-tube beneath water a copious effervescence was observed wherever the evolved gas came in contact with water ; and as this effervescence n7as accompanied by the formation of a flocculent precipitate of oxide of zinc it could only be caused by the presence of the vapour of zinc-methylium which on coming in contact with water would be instantaneously decomposed into oxide of zinc and hydride of methyl.The gas ,8 evolved by the action of water upon the solid and liquid products of the decomposition was found as might have been anticipated to be pure hydride of methyl derived from the dccom- position of the zincmethylium with which the crystalline residue of iodide of zinc was saturated. ZTNCETEIYLIUM (c,H zn) and ZINCAMYLrUnl (Clo€Il1Zn) are formed under precisely similar circumstances the iodides of ethyl and arnyl being respectively substituted for iodide of methyl. They are colourless and transparent liquids refracting light strongly and * Chem.SOC. Qu. J. 11 265; 111 30. 65 0R G AN IC T3 0l31 E S COYT.\1 N 1NG AX ET .4T.S. possessing a peculiar penetrating odoiir. They arc less volatile than zincmethyliuni and are also somewhat weaker in their powers of combination. They uhite directly with oxygen chlorine kc. and are decomposed in contact with water in a manner perfectly analo- gous to zincmethylium producing oxide of zinc and the hydrides of ethyl and amyl respectively. ACTION OF MERCURY UPON IODIDE OF ME'I'HYL. When iodide of niethyl is exposed to sunlight in contact with metallic mercury it soon becomes coloured red from the separation of free iodine ;after several hours' exposure this coloration disappears and a small quantity of the yellow iodide of mercury subsides to the bottom of the liquid.After the action of sunlight for several days the bulk of the mercury is obscrved to have considerably diminished; white crystals begin to be deposited around the sides of the glass vessel ;and finally after about a week's exposure the liquid solidifies to a colourless crystalline mass ; when this is digested with ether the new compound dissolves and is thus separated from metallic mercury and a small quantity of iodide of mercury which is col- laterally formed. Only a very small quantity of gas is evolved during the forination of this white crystalline compound. By spon- taneous evaporation the ethereal solution solidifies to a mass of minute colourlcss crystalline scales ; these dried iii z'acuo and submitted to analysis yielded results closely corresponding with the formula C €1 Hg I.This compound is therefore evidently the iodide of a iiew organo- metallic radical consisting of one atom of methyl and one atom of mercury and for which I propose the name HYD~~ARGY~~ORIETHYLIUM its iodide is formed by the direct union of one atom of mercury with one atom of iodide of methyl under the influence of light. 'gH3'} = C,H,HgI. fk Iodide of hydrargyromethylium is a white solid crystallizing in minute nacreous scales which are insoluble in water moderately soluble in alcohol and very soluble in ether and iodide of methyl; by the spontaneous evaporation of these solutions the crystds are again deposited unchanged. Iodide of' hydrargvroniethylium is slightly volatile at ordinary temperatures and exhales a slight but peculiarly unpleasant odour which leaves a nauseous taste upon the palate for several days; at 100' C.the volatility is much greater and the crystals are rapidly dissipated at this temperature when exposed to a current of air. At 143' C. it fuses and sublimes without decomposition condensing in brilliant and extremely thin crystalline plates. In contact with solutions of the fixed alkalies and ammonia I'OL. V1.-NO. XXI. P DR.. E. FRANKLAND ON A NEW SERIES OF it is converted into oxide of hydrargyromethylium which is dissolved in excess of all these reagents; from these solutions snlphide of ammonium throws down sulphide of hyilrargyromethylium as a slightly yellow flocculent precipitate having a most insupportable odour.I have not yet further examined the reactions of this remarkable body nor have I attempted the isolation of the hydrar- gyromethylium. A corresponding cornpound containing amyl is formed though with difficulty under similar circumstances; but I have not yet succeeded in producing one containing ethyl the iodide of this radical yielding as I have shown,* when exposed to sunlight in contact with mercury iodide of mercury and a mixture of ethyl hydride of ethyl and olefiant gases. I have also made some preliminary experiments with other metals and find that most of them are capable of thus entering into com- bination with the organic groups methyl ethyl and amyl amongst those which thus combine under the influence of light most readily and seem to promise the most interesting results I may mention arsenic antimony chromium iron manganese and cadmium.Imperfect as our knowledge of the organo-metallic bodies may yet appear I am unwilling to close this memoir without directing atten- tion to some peculiarities in the habits of these compounds which promise at least to throw some light upon their rational constitu- tion if they do not lead to extensive modifications of our views respecting chemical compounds in general and especially that interesting class termed conjugate compounds. That stanethylium zincmethylium hydrargyromethylium &c. are perfectly analogous to cacodyl there can be no reasonable doubt inasmuch as like that body they combine directly with the electro- negative metalloids forming true salts from which in most cases and probably in all the original groups can be again separated unaltered; and therefore any view which may be taken of the new bodies must necessarily be extended to cacodyl.The discovery and isolation of this so-called organic radical by 13 unsen was certainly one of the most important steps in the development of organic chemistry and one the influence of which upon our theoretical views of the constitution of certain classes of organic compounds can scarcely be too highly estimated. It was impossible to consider the striking features in the behaviour of this body without finding in them a most remarkable confirmation of the theory of compound radicals as propounded by Berzelius and Liebig.The formation of cacodyl its habits and the products of its * Chem. Sac. Qu. J. 111 331. OEtGSNIC BODIES CONTAINING METALS. decomposition have for some time left no doubt of the existence of methyl ready formed in this body; and Kolbe,* in developing his views on the so-called conjugate compounds has proposed to regard it as arsenic conjugated with two atoms of methyl (C,H,; As. So long as cacodyl was an isolated example of an organo-metallic body this view of its rational composition harmonizing as it did so well with the facts elicited during the route of cacodyl through its various combinations and decompositions could scarcely be con-tested; but now since we have become acquainted with the proper- ties aud reactions of a considerable number of analogous bodies circumstances arise which I consider militate greatly against this view if they do not render it absolutely untenable.According to the theory of conjugate radicals just alluded to cacodyl and its congeners so far as they are at present known would be thus represented Cacodyl . Oxide of cacodyl . Cacodylic acid . Stanmethylium . Stanethylium . Oxide of stanethyliuni . Stanamylium . Zinc met hyliuni . Zincethylium . Zincam vlium StibethLe (Stibethyl) . Binoxide of stibethine Oxide of stibmethylium . Hydrargyromethylium . Iodide of hydrargyromethylium . It is generally admitted that when a body becomes conjugated its essential chemical character is not altered by the presence of the conjunct; thus the series of acids C,H,O, formed by the con-junction of the radicals C Hc,,+l)with oxalic acid have the same neutralizing power as the original oxalic acid and therefore if we assume the organo-metallic bodies to be metals conjugated with various hydrocarbons we might reasonably expect that the chemical relations of the metal to oxygen chlorine sulphur &c.would remain unchanged. A glance at the formula of these compounds will however suffice to show that this is far from being the case. It is true that cacodyl forms protoxide of cacodyl and cacodylic acid corresponding the one to a somewhat hypothetical protoxide of arsenic which if it exist does not seem to possess any well-defined * Chem.SOC. Qu. J. 111 372. P2 Dn. E. FRANKLAND ON A XEW SERTES OF basic character and the other to arsenious acid; but no compound corresponding to arsenic acid can be formed; and yet it cannot be urged that cacodylic acid is decomposed by the powerful reagents requisite to producc further oxidation for concentrated nitric acid may be distilled from cacodylic acid without decomposition or oxidation in the slightest degree. The same anomaly presents itself even more strikingly in the case of stanmethyliurn which if n-e are to regard it as a conjugatc radical ought to combine with oxygen in two proportions at least to form compounds corresponding to protoxide and peroxidc of tin. Stanethylium rapidly oxidizes when exposed to the air and is converted into pure protoxide; but this compound exhibits none of that powerful tendency to combine with an additional equivalent of oxygen which is so characteristic of grotoxide of tin; nay it may even be boiled with dilute nitric acid without evincing any signs of oxidation.I have been quite unable to form any higher oxide than that described above it is only when the group is cntirely broken up and the ethyl separated that the tin can be induced to unite with another equivalent of oxygen. Stibethyl also rcfuses to unite with more or less than two equivalents of oxygen sulphur iodine &c. and thus forins conipounds which are not at all represented amongst the combinations of the simple metal anti-mony. When the formulz of inorganic chemical compounds are con-sidered even a superficial observer is struck with the great symmetry of their construction ; the coinpounds of nitrogen phosphorus an-timony and arsenic especially exhibit the tendency of these elements to form compounds containing three or five equivalents of other elements and it is in these proportions that their affinities are best satis-fied ;thus in the ternal group we have NO, NH, NI, NS,,.PO, PH3 PCl, Sb 0,,Sb H, Sb Cl, As O, As H, As Cl, &c. and in the five-atom group NO, NH,O NH I PO, YH I &c. Without offering any hypothesis regarding the cause of this symmetrical grouping of atoms it is sufficiently evident from the examples just given that such a tendency or law prevails and that no matter what the character of the uniting atoms may be the cornljining power of the attracting element if I may be allowed the term,is always satisfied by the same number of these atoms.It was probably a glimpse of the operation of this law amongst the more complex organic groups which led Laurent and Dumas to the enunciation of the theory of types; and had not those distinguished chemists extended their views beyond the point to which they were well supported by then existing facts had they not assumed that the properties of an organic compound are dependant upon the position and not upon the nature of its single atoms that theory would undoubtedly have contributed to the de- velopment of the science to a still greater extent than it has already done.Such an assumption could only have been made at a time ORGANIC BODIES COKTAINING METALS. when the data upon which it was founded were few and imperfect and as the study of the phenomena of substitution progressed it gradually become untenable and the fundamental principles of the electro-chemical theory again assunied their sway. The formation and examination of the organo-metallic bodies promises to assist in effecting a fusion of the two theories which have so long divided the opinions of cheniiets and which have too hastily been conceived irre- concileable; for whilst it is evident that certain types of series of cornpounds exist it is equally clear that the nature of the body derived from the original typc is essentially dependent upon the electro-chemical character of its chemical atoms and not merely upon the relative position of those atoms.Let us examine for instance the compounds formed by zinc and antimony by com-bination with one equivalent of oxygen the electro-negative quality of the zinc is nearly annihilated and it is only by the highly oxidizing peroxide of hydrogen that the metal can be made to form a very instable peroxide ; but when zinc combines with one equivalent of methyl or ethyl its positive quality so far from being neutralized is exalted by the addition of the positive group and the compound now exhibits such intense affinity for the electro-negative elements as to give it the property of spontaneous inflammability. Peroxide of antimony has also little tendency to pass into a higher state of oxi-dation; but when its three atoms of oxygen are replaced by the electro-positive ethyl as in stibethine that affinity is elevated to the intense degree which is so remarkable in this body.Taking this view of the so-called conjugate organic radicals and regarding the oxygen sulphur and chlorine compounds of each metal as the true molecular type of the orgario-metallic bodies derived from it by the substitution of an organic group for oxygen sulphur &c. the anomalies above mentioned entircly disappear and we have the following inorganic types and organo-metallic derivatives Inorganic types. Organo-metallic derivatives. . . . As{ E Cacodyl. < [C Hi . . . ,4s{ C,H Oxide of Cacodyl. lo $52 H3 I c H3 .. . As4 0 Cacodvlic Acid. J 10 10 . . . Zn (C H,) Zincmethylium. . . . Zn{ ',OH Oxide of Zincmethylium. DR. E. FRANKLAND ON A NEW' SERIES OF Inorganic types. Organo-metallic derivatives. (0 :c4 H5 SbcO . . . . Zn( C €1 Stibethine. Lo tc'i H5 f0 ,C Hi C H, lo SbcO . . . . Sbl C H5 Binoxide of Stibethine. lo lo 10 1 SbO.. . [: SnO.. . . Sn (C,N,) Stanethylium. sn{E . . . . Sn{ 'c'5 Oxide of Stanethylium. Hg{ '2:3 The only compound which does not harmonize with this view is ethostibilic acid to which Lowig assigns the formula C,H5Sb05 ; but as that chemist has not yet fully investigated this compound it is .possible that further research may satisfactorily elucidate its appa- rently anomalous composition.It is obvious that the establishment of this view of the constitution of the organo-metallic bodies will remove them from the class of organic radicals and place them in intimate connection with am-monia and the bases of Wurtz Hofmann and Paul Thenard; in-deed the close analogy existing between stibethine and ammonia first suggested by Gerh ardt has been most satisfactorily demonstrated by the behaviour of stibethine with the haloid compounds of methyl and ethyl. Stibethine furnishes us therefore with a remarkable example of the law of symmetrical combination above alluded to and shows that the formation of a five-atom group from one containing three atoms can be effected by the assimilation of two atoms either of the same or of opposite electro-chemical character ; this remark- able circumstance suggcsts the following question.Is this behaviour common also to the corresponding compounds of arsenic phos- phorus and nitrogen; and can the position of each of the five atoms with which these elements respectively combine be occupied indif- ferently by an electro-negative or an electro-positive element ? This question so important for the advance of our knowledge of the organic bases and their congeners cannot now long remain tin- answered. If the views which I have just ventured to suggest should be as Hg( . . . . Iodide of Hydragyromethylium. ORGANIC BODIES CONTAINING METALS. well supported by future researches as they are by the facts already known they must occasion a profound change in the nonicnclature of the extensive series of compounds affected by them.I have not however ventured to introduce this new system of nomenclature even in the case of the new bodies described in this memoir ; since hasty changes of this kind unless absolutely necessary are always to be deplored. In accordance with the suggested view of the constitution of the organo-metalic compounds the following plan of nomenclature would probably be found most convenient. ARSENIC COMPOUNDS. (C,H3 )2As . . Bimethide of Arsenic (Cacodyl). (C H3 )2 As0 . . Birnethoxide of Arsenic (Oxide of Cacodyl). (C H )z AsO . . Bimetharsenic Acid (Cacodylic Acid). ZlNC COMPOUNDS. Methide of Zinc (Zincmethyliurn). Ethide of Zinc (Zincethylium).Amylide of Zinc (Zincamylium). TIN COMPOUNDS. (C H,) Sn . . Methide of Tin (Stanmethylium). (C H3) SaI . . Alethiodide of Tin (Iodide of Stanmetliylium). (C €I5) SnO . . Ethoxide of Tin (Oxide of Stanethylium). (CloH1,) SnCl . . Amylochloride of Tin (Chloride of Stanamylium). ANTIMOXY COMPOUNDS. (C €13)3Sb . Termethide of Antimony (Stibmethine). (C H,),SbO . . Quadromethoxide of Antimony (Oxide of Stibmethylium). (C W5) SbO . . Terethobinoxide of Antimony (Binoxide of Stibethine). MERCURY COMPOUNDS. Methide of Mercury (Hydrargyromethylium). Methiodide of Mercury (Iodide of Hydrargyromethylium). In naming the new bodies described in the present paper I have in conformity with the nomenclature of the organic bases adopted the principle of employing the termination ‘‘ium,” when the body unites with one equivalent of oxygen chlorine &c.like ammonium and the terminal “ine,” when like ammonia it combines with two additional atoms. ME. HENRY HOW UN On Meconic Acid and its Derivatives. BY Henry HOW.* This investigation was undertaken with the view of determining whether compounds analogous to those already described by the author? as derived from conieriic acid could be obtained under similar circuinstances from meconic acid. To obtain pure nieconic acid the crude acid-prepared by treating meconate of lime three times in succession with 20 parts of boiling water and 3 parts of strong hydrochloric acid-is mixed with about twice its weight of water and heated over the water-bath with con- stant agitation and caustic ammonia added till the whole is dissolved; the ammoniacal salt thus formed is very soluble in boiling water and solidifies on cooling.The solid mass is subjected to strong pres- sure to remove the mother-liquid and purified by three crystalliza- tions from the smallest possible quantity of boiling water the mother-liquor being expressed at each crystallization. The product is a perfectly white salt frorii the solution of which in hot water the iiieconic acid may be separated by hydrochloric acid in colourless shining lamin=; and on washing the precipitate a little with cold water and dissolving in the smallest possible quantity of boiling. water the solution on cooling yields the acid in a state of perfect purity.Bihasic Meconate of Arnrnonia.-The salt whose preparation has just been described crystallizes from moderately dilute solutions after standing in radiated groups of fine silky needles having an acid reaction. The salt dried at 100" has the composition EIO,2NH 0 . C, €loll. It is very hygroscopic. The crystals appear to contain variable quan- tities of water of crystallization. An aqueous solution of this salt may be boiled without change; but when kept boiling for some time with an excess of ammonia it becomes altered. Action of Heat on Meemate of Ammoniu.-Comenumic Acid.-Some of the highly coloured mother-liquors of the purifying process were retained at or near the boiling teniperature aniriionia being present in excess and hydrochloric acid added after cooling.Carbonic acid was then copiously evolved and a considerable precipitate formed coiisisting of comenarnic acid C, 1-1 NO, which by repeated crystal- lization from boiling water and the use of animal charcoal was ob- tained in colourless shining scales. Its formation from bibasic rne-conate oi ammonia may be represented by the following equation HO .2NH 0 . C, H . O, =C, H NO + NH + 2EIO + 2C0,. * Edirib. Plril. Trans. XX Pt. 111 101 ; Ann. Ch. Pharm. LXXXIII 330. .f-Chem. SOC. Qn. J. IV 362. MECONIC ACID AN11 1TS DERIVATIVES. This reaction offers a convenient source of comenamic acid as very impure meconic acid may be used. Action oj Chlorine on Bibusic Meconate of Ammonia.-Chlorine passed through the coloured mother-liquor deprives it of colour con- siderably and causes a deposit of hard granular crystals which may be purified by recrystallization from boiling water.Hard crystals are then deposited which when magnified appear to consist of thick needles radiating from a centre. The salt thus formed contains no chlorine but is a monobasic meconate of ammonia 2H0 .NH,O .C, HO,,. The crystals likewise contain 7.70 per cent of water of crystallization =2Aq. The original mother-liquor of this salt deposited a further quantity of the same on being concentrated but by continued evaporation crystals of a different character were obtained; and these when re- crystallized from boiling water presented themselves in the form of square prismatic needles having the properties and composition of chlorocomenic acid 2H0 .C, { El> 0 The last mother-liquors of this process contain oxalic acid.Action of Bromine on Meconic Acid.-When bromine-water is poured upon powdered meconic acid carbonic acid is evolved with lively effervescence arid the acid dissolves forming a solution which after a while deposits long prismatic crystals of great beauty; a much more copious product is however obtained by gentle evapo- ration. By recrystallization from hot water brilliant square prismatic crystals are obtained which when dried at 100’ C. have the com-position of dry bromocomenic acid. 2HO .C, {B” 0,. The nature of the reaction is shown by the equation Crystals of oxalic acid were obtained by evaporating the mother- liquors to a small bulk The action of bromine on meconate of ammonia would doubtless be found similar to that of chlorine.OF MECONIC ETHERS Acm.-\”7en a current of dry hydrochloric acid gas is passed through an alcoholic solution of meconic acid till it fumes strongly and the liquid is set aside to cool there appears after a time shorter or longer as the alcohol is stronger or weaker a deposit of feathery crystals. If absolute alcohol has been used the filtered liquid yields no further deposit; but if rectified spirit has been used another less crystalline substance appears after a time. On evaporating the liquid which has ceased to give deposits to cotn-plete dryness the chief constituent of the residue is found to be a substance which fuses under boiling water.It is more or less accompanied by the other bodies according to the strength of the alcohol used. Ethylomeconic Acid-This is the first deposit above mentioned ; it is formed most abundantly and in the state of greatest purity when absolute alcohol is used. One crystallization from hot water is sufficient to render it perfectly pure and uniforni and it then crystallizes in brilliant short needles. It is composed of C, H8014 and is an acid ether analogous to phosphovinic ether its rational formula being -2 HO .C H 0 .C1 HO,, or H Ethylomeconic acid when pure crystallizes from boiling water in which it is very soluble in brilliant small crystals which when magnified are seen to be square prismatic needles.It likewise dissolves readily in ether and commoii alcohol when warmed less readily in absolute alcohol. It separates from concentrated solu- tions in these three liquids in groups of stellate crystals and when left to spontancous evaporation in long needles. It is anhydrous; its crystals lose no weight either in vacuo or at 100' C. It fuses at about 158'-159' C. to a transparent yellowish liquid a sublimate of very brilliant rhombic crystals being formed at the same time. The aqueous solution has a strongly acid reaction imparts a deep- red colour to pcrsalts of iron and decomposes carbonates with effer- vescence. It is bibasic forming two series of salts; the acid salts are readily crystallizable. Its salts are very stable the acid being recoverable from them by decomposition with stronger acids.Acid Ethylorneconateof Baryta BaO .HO .C Hb0 .C14HO,, is formed on adding carbonate of baryta in successive small portions to water covering solid ethylomeconic acid. Lively effervescence ensues and the acid quickly disappcars a small quantity of an insoluble yellow salt being formed at the same time. If the liquid be filtered as soon as the effervescence ceases and the vesscl be placed in vacuo a considerable quantity of carbonate of lime previously held in solu- tion by the carbonic acid is deposited. By a second filtration a clear yellowish liquid is obtained which when evaporated in wacuo or at a gentle heat yields well-defined brilliant rhombic crystals of a yellow colour.The crystals contain water which they lose on drying. Acid Ethylomeconate of Silver Ago . HO .C H 0 .C, HO,,.-Obtained by adding an aqueous solution of the baryta-salt to nitrate of silver dissolving the washed precipitate in boiling water and crystalliziug. Forms groups of fine small stcllate crystals brilliant RIECONIC ACID AND ITS DERIVATIVES. '75 arid white It is remarkably stable remaining perfectly unchanged when exposed for a long time to the diffused daylight of summer. The crystals contain 2 atoms water which they give off at 100OC. An aqueous solution of acid ethylomeconate of baryta forms wi t acetate of lead a yellowish-white with sulphate- of copper a pale green and with perchloride of iron a red-brown precipitate; the last is readily soluble in an excess of the iron-salt forming with it a dark red liquid.Neutral Salts of Ethylorneconic Acid.-These salts have not yet been obtained quite pure. By saturating ethylomeconic acid with carbonate of baryta at 100°C. and filtering a salt was obtained in small short yellow needles which when dried at looo yielded 41.89 per cent baryta. The formula BaO .C H 0 .C, HO,, requires 42.19. The salts obtained by treating the acid with excess of carbonate of baryta were found to contain from 42 to 44.5 per cent baryta; whence it would appear that the acid forms basic in addition to neutral and acid salts. Similar results were obtained with the other alkaline earths. The acid when heated with excess of car-bonate of silver remains almost wholly undissolved in the form of some basic compound; heated with excess of potash or soda it yields meconutes of these bases.An excess of caustic ammonia decomposes it very readily. Meconumidic Acid.-When ethylomeconic acid is dissolved in warm water or alcohol and an excess of strong aqueous or alcoholic ammonia is added the liquid assumes a deep-yellow colour and becomes very soon filled with a yellow semi-gelatinous substance which after being washed with dilute spirit dries up in the air to an amorphous mass reducible with some difficulty to a very fine yellow powder. It appears to be the ammonia-salt of a peculiar acid; for on treating its solution in hot water with hydrochloric acid a white precipitate is formcd which on being recrystallized from boiling water is found to have the composition C H,? N 07!.It appears to be formed by the action of 7 atoms ammonia on 6 atoms of the acid ether thus 6 C, H 0l4-I-7 NH3+6 HO=C H3g N OY8+6C H 0 c-c-y-2 L-y-> y-Ethylomeconic acid. Meconainidic acid. Alcohol. If we suppose that the acid contains 6 atoms water of crystal-lization which are not given off at 100' C. its formula will be C H, N 072; which contains the elements of 6 atonis normal amidomeconic acid + 1 atom ammonia. C, H3 N OY2=6(2HO .NH2.C14H Ole) +NH,. The numbers obtained by analysis do not agree very well with this view of its constitution ; but that it is really an amidogen-compound resulting from meconic acid may be inferred from the fact that when MR.HENRY HOW ON it is heated with a solution of potash ammonia is evolved in con-siderable quantity and the liquid gives with hydrochloric acid a crystalline precipitate consisting of bimeconate of potash which upon subsequent treatment in the same manner is converted into meconic acid. The appropriation of the atom of ammonia among the 6 atoms of amidomecoiiic acid (if indeed this be the constitution of the com-pound) appears to have much diminished the basicit,y of the complex atom or else the yellow salt is not a neutral one. The amidomeconic acid being bibasic 6 of its atoms should in forming a neutral salt take up 12 atoms ammonia; but it appears to contain only 9 atonis its forniula as deduced from analysis being 9 NH 0 .C, H, N 0, +3 Aq.; and the acid itself considered with regard to its amount of basic water as indicated in the salt is represented thus 9 HO .C, H, N 0, +6 Aq. The yellow salt when examined by the microscope does not present any appearance of crystalline structure but appears to consist of round translucent granules which when deposited slowly from dilute solutions look like small yellow vesicles or air-bubbles. It dissolves readily in hot water exhaling a decided smell of ammonia; it is very sparingly soluble in hot alcohol insoluble in cold alcohol. It gra-dually gives off ammonia when heated in the dry state to ZOO0 C.; at a higher teniperature it blackens and fuses. Attempts were made to prepare the other salts of the acid by pre-cipitating metallic solutions with the ammonia-salt ; but no definite products were obtained.Coupled Ether of Meconic Acid.-Mecono-ethylomeconic Acid.- This is the substance already described as occurring in the process of making the ethers of meconic acid when rectified spirit is employed ; it is deposited gciierally after the first product of ethylomeconic acid is filtered off. On redissolving it in hot watcr two or three times and cooling the liquid a white amorphous powder is obtained the analysis of which agrees pretty nearly with the formula C, II, OZ8,which contains the elements of 1 atom meconic and 1 atom ethylorneconic acid C,,H,20,,=3H0.C,,H0,,+2 HO.C,H,O. C,,HO,,. That the substance is more than an accidental mixture appears from its behaviour with ammonia.On adding alcohol to a concentrated aqueous ammoniacal solution of the substance a deposit appears con- sisting of small radiated silky tufts; and when such an aqueous solution is evaporated to dryness at 100' C. a crystalline residue remains which is very sparingly soluble in boiling water; the more MECONIC ACID AKD ITS DERIVATTT'ES. '77 soluble portion gives with hydrochloric acid a crystalline precipitate in the form of needles. Want of material prevented the further examination of these products. Biethylomeconic Acid HO .2C H 0 .C, HO,,. -This sub-stance is found in considerable quantity in thc acid mother-liquors froni which the bodies before described have been deposited espe- cially when absolute alcohol has been used its proportionate amount appearing to depend on that of the hydrochloric acid gas passed through the solution.It remains on evaporating the liquid till acid ceases to be evolved at 10QoC. in the form of a thick oil or viscid mass which becomes a crystalline solid on cooling. It may be purified by recrystallization. The same compound may be obtained by distilling meconic acid with absolute alcohol and strong sulphuric acid. Alcohol and ether distil over and a syrupy mass remains which when poured into a comparatively large quantity of cold water yields after a while a crystalline precipitate of a rose-pink colour. On recrystallization from water it formed colourless flattened prisms which when dried at looo were found to be identical in composition with the above.Rectified spirit cannot be substituted for absolute alcohol in this process. Biethylorneconic acid in its pure state as crystallized from water occurs in the forin of long flattened colourless prisms ;under boiling water it fuses before dissolving. It is very soluble in alcohol. In the dry state it fuses at about 110' C. to a yellowish transparent liquid. Its aqueous solution readily coagulates white of egg has an acid reaction and decomposes carbonates with effervescence. It imparts a red colour to ferric salts. It is monobasic. Biethylomeconale of Ammonia.-When ammoniacal gas is passed through a solution of the ether in nearly absolute alcohol the whole becomes a yellow nearly solid mass; and this when freed by pressure from the ammoniacal alcohol and dissolved in hot spirit crystallizes in tufts of radiated yellow silky needles.This salt contains no water its colriposition being expressed by the formula NH 0.2C H 0.C, HO,,. Biethylomeconate of ammonia dissolves readily in cold water forming a yellow solution from which acids throw down the un- changed ether. The solution gives the following reactions With nitrate of silver a yellow gelatinous precipitate insoluble in boiling water and apparently unaltered by elevation of temperature ; with sulphate of copper a green gelatinous precipitate ; with acetate of lead a heavy yellowish-white; with sulphate of magnesia a crys-talline precipitate ; with the chlorides of barium strontium and calcium it produces pale yellow semi-gelatinous precipitates inso- AIR.JAMES BROWN ON SOME S.4LTS AKD luble in boiling water but readily soluble in excess of the earthy salts. The baryta-salt dried at loo" C. hits the coinposition Ba0.2 C H 0 .C, HOll. Biethylomeconic acid den heated with ammonia appears to un-dergo a change the result of which is probably an acid amide. On some Salts and Decomposition-Products of Pyromeconic Acid. By James Brown." Pyromeconic acid was discovered by Scr turn e r and long regarded as sublimed meconic acid till Robiquet in 1832 obtained meconic acid the substance from which pyromeconic acid is formed and showed that the acid obtained from opium exhibits characters different from those of the sublimed acid. He prepared the lead-salt of pyromeconic acid and showed that its formula is PbO.C, H 0,. Liebig pointed out that pyronieconic acid has the same composition as pyromizcic acid and regarded it as probable that the two acids were identical. This supposition however has been completely refuted by Stenhouse. The pyromeconic acid used in the following investigation was pre- pared by distilling impure meconic acid (prepared by twice treating crude meconate of lime with hydrochloric acid) at a temperature between 260' and 315' C. It was purified by once pressing it between bibulous paper and then subliniing at rather a low temperature in a cylindrical vessel fitted with a number of transverse diaphragms of filtering-paper. By this treatment the acid was obtained colourless and pure enough for the preparation of all its salts and products of decomposition.The acid thus obtained assumes the form of large beautiful trans- parent tables which dissolve readily in water and alcohol both at high and at low temperatures from which solutions it again crystallizes in tolerably large four-sided prisms. It is slightly acid to litmus-paper and retains this acid reaction even after three crystal- lizations from boiling water. It volatilizes completely at 100' C. a property which may be used to test its purity from paranieconic acid (with which it is always contaminated at the first sublimation), inasmuch as the latter requires a much higher temperature to vola- talize it. Pyrorneconic acid gives a deep red colour with ferric salts and forms no precipitate with the chlorides of calcium barium and man- * Phil.Mag. [a] IV 16. ; Ann. Ch. Pharm. LXXXIV 32. ~ECOMPOSITION-PRODUCTS OF PY ROMECONIC ACID. ganese or with sulphate of magnesia either at high or at low temperatures even on the addition of ammonia. With corrosive sublimate it forms after a while a white amorphous precipitate which redissolves on boiling. On treating a hot aqueous solution of pyro-meconic acid with strong caustic potash in excess and leaving it to stand for some hours it soon yields crystals consisting of the acid in its original state. A similar experiment was made with ammonia bixt it led to the Bame result in both cases the liquid became nearly black. The formula of pyromeconic acid is HO .C, H 0,.or C, H 0,. Pyroinecoizate of Baryta.-Obtained by mixing a warm amnio-niacal solution of pyromeconic acid with acetate of baryta the salt being then deposited after a short time in small colourless silky needles. In dilute solutions they do not form immediately but their formation goes on very quickly when once begun. This baryta-salt is the most soluble of all the earthy pyromeconates water at 15.5' C. dissolves 2.50 per cent of it. It is but slightly soluble in alcohol. Like all the pyromeconates it has a strong alka- line reaction and gives with sesquichloride of iron a faint red colour- ing which however is stronger when crystals of the salt are used instead of the solution. On evaporation in vacuo the salt is deposited in short prisms of a yellowish colour.It loses nothing in weight by exposure to a temperature of loo" but when more strongly heated it burns with slight incandescence without previously melting. The salt when thoroughly washed with alcohol and dried at 100"C. was found to contain BaO .C, H 0, or BaO . C, H 0 +HO. Pyromeconate of Strontia SrO . C, 11 0 + H0.-On mixing an alcoholic solution of nitrate of strontia with an alcoholic solution of pyromeconic acid which has been made ammoniacal a precipitate is immediately formed consisting of small silky needles which by recrystallization from water may be obtained in stellate groups having a ycllowish colour. The salt obtained by precipitation is colourless slightly soluble in water and alcohol at ordinary temperatures more solubie at higher temperatures and has a strong alkaline reaction.Water at 20' C. dissolves 1.3per cent of it. It does not lose weight at 100'; at higher temperatures it does not melt but burns with a slight explosion. Pyromeconate of Lime CaO. C, H 0 +H0.-Obtained in the form of small colourless silky needles by adding an excess of a solu- tion of acetate of lime to a warm ammoniacal solution of pyromeconic acid. It is slightly soluble in warm alcohol somewhat more soluble in water from which it crystallizes as the solution gradually cools in crystals of considerable magnitude. Water at 15.5' C. dissolves 0.31 per cent of it. Pyromeconate ~f Magnesia Mg0. C, H O,.-A warm aqueous solution of pyromeconic acid forms with acetate of magnesia a white SO MR.JAMES BROWN ON som SALTS AXD amorphous precipitate insoluble in water and alcohol. The reactions of this salt are exactly like those of the other pyromeconates. It does not lose weight at 100'. It appears to be the only earthy pyromeconate which contains no water. Pyromeconate of Lead PbO. C, H O,.-Robiquet obtained this salt by adding hydrated oxide of lead to a hot solution of pyromeconic acid. It may also be formed by adding a warm concentrated ammo- niacal solution of pyromeconic acid to acetate of lead whereupon thcre is immediately deposited a dense crystalline powder which rapidly increases if the liquid be briskly stirred. The crystals are but sparingly soluble in hot water and still less soluble in alcohol whether hot or cold.The precipitated salt is colourless but when exposed to daylight quickly turns yellow. It does not lose weight at looo even in the course of three or four hours. Pyrorrtecoiiate of Copper CuO. C, H O,.-S tenhouse obtained this salt by boiling the acid with hydrated oxide of copper, and leaving the filtered solution to cool. It may also be formed by mixing ammonis-sulphate of copper with a warm aqneous solution of pyromeconic acid ; a precipitate is then formed consisting of green shining crystalline needles which are very brittle and easy to pnl- verize. The crystals require a tolerably large quantity of hot water to dissolve them; in cold water and in alcohol they are but very slightly soluble. Pyrorneconate of Ferric Oxide Fe O,3.C, H 05.-This salt has been fully described by Stenhouse who obtained it by boiling pyrorneconic acid with hydrated ferric oxide or with ferric sulphatc. It may likewise be formed by adding sesquichloride of iron to a hot concentrated aqueous solution of the acid ; cinnabar-coloured crystals then gradually appear and attach thcmselves to the sides and bottom of the vessel. DECOMPOSITION-PRODUCTS OF PYKOMECONIC ACID. When a few crystals of pyromeconic acid are moistened with strong nitric acid they immediately assume a white gelatinous appearance and bubbles of nitrous acid are soon given off. On applying a moderate heat the action becomes extremely violent and remains so even if the application of heat be discontinued ; oxalic acid and hydrocyanic acid are simultaneously produced.-Sulphuric acid does not act on pyro- meconic acid in the cold but dissolves it at a gentle heat forming a colourless liquid from which the pyromeconic acid is again deposited on cooling.-W'hen chlorine is passed into a solution of pyromeconic acid no substitution-product is formed the action being apparently too violent for that result; in fact the acid is completely decom- posed and the liquid is afterwards found to contain oxalic acid though not in large quantity.-The author did not succeed in form- DECOMPOSITION-PRODUCTS OF PYROMECONIC ACID.ing an ether by passing dry hydrochloric acid gas through a solutioii of the acid in absolute alcohol the crystals which separated out from the liquid proving to be nothing but the unaltered acid.Action of Bromine on Pyromeconic Acid-M'hen bromine water is added to a strong aqueous solution of pyromeconic acid the latter being in excess the bromine is quickly taken up and there remains a colourless liquid which after standing for an hour or less de- posits beautiful small colourless crystals of Bromupyromeconic Acid C, 0,. This acid is slightly soluble in cold water somewhat more soluble in hot water and reddens litmus slightly. It dissolves readily in boiling alcohol and crystallizes from this solution in beau- tiful tables which however if the cooling be carefully conducted are replaced by short prisms. With ferric salts the acid gives a deep purple-red colour totally distinct from the red produced by the original acid.Nitric acid decomposes it with effervescence but sul-phuric acid dissolves it without visible decomposition. When sub- jected to dry distillation it fuses and afterwards blackens giving off hydrobromic acid in large quantity. If the heat be allowed to act upon it for a longer time a white crystalline substance begins to collect in the cold part of the tube; but the quantity of this substance obtained was too small for examination. The acid gives no precipitate with nitrate of silver and does not reduce the oxide to metallic silver on boiling; neither does it produce any precipitate in solutions of chloride of barium chloride of calcium or sulphate of magnesia even in presence of ammonia. With ammonio-sulphate of copper it exhibits no reaction in the cold but on the application of heat a bluish precipitate is formed.Bromop yromeconic acid is monobasic like pyromeconic acid. Lead-salt PbO. C, H Br 0,+ H0.-A warm alcoholic solution of the acid forms with an alkaline solution of acetate of lead a white precipitate consisting of small dense crystalline needles which quickly settle down to the bottom of the vessel. This salt may also be obtained by mixing the aqueous solutions of the acid and of acetate of lead and adding ammonia; but when thus prepared it is very dark-coloured. It does not lose weight at 100'. The author has likewise obtained a substitution product of pyro- meconic acid with iodine. VOL. VI.-NO. ?[XI. PROFESSOR BUNSEN ON Researches on Chemical Afllnity.By R. Bunsen.’ FIRST MEMOIR. The force which is regarded as the cause of chemical affinity may as is well known be increased and diminished by various influences. Its magnitude varies under the influence of light heat and elec- tricity; it changes with the proportion of the acting masses and is esseiitially modified by the state of aggregation of matter as well aq by the contact of the acting body with bodies substantially different. It may therefore be regarded as a function of all these influences. If the mathematical form of this function could be determined it would afford a measure of the absolute magnitude of the force itself. Claude Berthollet the celebrated author of the “Statique Chi- mique,” was the first to regard the cause of chemical phenomena from this point of view.JIis sagacious contempla.tions led him to assume that particular law of the action of masses which was named after him and is still at the present day regarded as valid and by which he thought he could express the relation of the force of chemical affinity to the mass of the combining bodies. According to this law a body to which two different substances capable of uuiting chemically with it are presented in different proportions divides itself between these substances in the ratio of the products of their relative masses into the absolute strengths of their chemical affinities for it. Thus if the masses of the two bodies which are present in excess be denoted by A and B the respective coefficients which denote their absolute affinities for the body C by cc and p and the quantities of A and R which actually combine with C by a and b; then will these quantities be to another as uA,PB i.e. a b=aA PB. Hence the rates of the absolute affinity of A to C and B to C is given by the equation CL -aB P bA It appeared to me a matter of great interest to subject this law which as yet is destitute of any experimental support to an exact investigation. The result of this exauiination has been to establish not Berthollet’s but a totally different law which promises to exert a not unimportant influence on our views of the mode of action * Ann. Ch. Pham. LXXXV. 137. RESEARCHES ON CHEMICAL AFFINITY. of chemical affinity. The substance of this new law may be corii- prised in the following theorems.1. When two or more bodies B B’ are presented in excess to the body A under circumstances favourable to their combination with it the body A always selects of tlie bodies B 23’ . . . . quantities which stand to one another in a simple stoYchiometrica1 relation; so that for 1,2,3.. . . atoms of the one compound there are always formed 1,2 3 4. . . . atoms of the other. 2. If in this manner there is fornied an atom of the compound A’ +B’ in conjunction with an atom of A + B the mass of the body R may be increased relatively to that of B‘ up to a certain limit without producing any change in that atomic proportion. 3. When a body A exerts a reducing action on a compound B+ C present in excess so that A and B conibine together and C is set free; then if G can in its turn exert a reducing action on the newly formed compound the final result of the reaction is such that the reduced part of B+ C is to the unreduced portion in a simple atomic proportion.4. In these reductions also the mass of the one constituent may without altering the existing atomic relation be increased up to a certain limit above which that relation undergoes changes by definite steps but always in the proportion of simple rational numbers. It is not surprising that these remarkable relations have hitherto passed unobserved seeing that they only arise when the phenomena of combination which are regulated by them take place quite simultaneously.For even if the body A were originally to select for combination from the bodies B and C quantities bearing to one another a simple atomic relation but the combination of &4 and B were to take place in shorter time than that of A and C it would follow of necessity that during the whole term of the process the ratio of B to C and consequently also the mutual atomic relation of the associated compounds would change so that the observed pro- portion would be no longer definite but mixed. The same result must follow if the bodies which are combining side by side be not homogeneously mixed in the beginning. Thc law will therefore be most easily recognisable when these relations do not exert a disturbing action as for example in combustible gases which before combus- tion exist in a condition of static equilibrium.I shall therefore in the following investigations chiefly avail myself of such mixtures. When carbonic oxide and hydrogen are exploded with a quantity of oxygen not sufficient to burn them completely the oxygen divides itself between the two gases according to the law above mentioned in such a manner that the quantitics of carbonic acid and water pro-duced stand to one another in a simple atomic proportion. The conibustions were made in a eudiometer which allowed the 62 PROFESSOR BUNSEN ON pressure to be varied at pleasure. (For the description of the apparatus see the original Memoir). The hydrogen used in the experiments was obtained by electrolysis and the carbonic oxide by the action of sulphuric acid upon formiate of magnesia; the latter after being washed with potash-ley was found to be quite pure.I. A mixture of detonating gas (2 vol. H + 1 vol. 0 obtained by electrolysis) and carbonic oxide containing in 100 parts Carbonic oxide . . . . 72.57 Hydrogen . . . . . 18.29 Oxygen . . . . . . 9-14 100~00 was divided into two portions. The first portion burnt in the dark at Om-7338and 22 3OC. gave for the proportions of CO and H con-sumed Found. Calculated. Carbonic oxide . . . 12.28 2 vols. 12-19 Hydrogen . . . . 6.00 1 vol. 6-09 7 7 18.28 18.28 11. The second portion burnt in the dark at Om*7324 and 22.5' C. gave Found. Calculated. Carbonic oxide . . . 12-09 2 vols. 12.19 Hydrogen .. . . 6.19 1 vol. 6-09 -18-28 18-28 111. A similar mixture containing in 100 parts Carbonic oxide . . . . 59-93 Hydrogen . . . . . 26.71 Oxygen . . . . . 13-36 when burned in daylight at O"03952 and 22*5OC. gave for the quantities consumed in 100 parts Carbonic oxide . . . 13.06 1 vo1. 13.36 Hydrogen . . . . . 13.66 1 , 13.36 In Exp. I. and II. the ratio of the oxygen to the combustible gases was 10:99.4 and that of the hydrogen to the carbonic acid 10:39.7. The mixture gave in two combustions the proportions of 1 vol. hydrogen burned to 2 vols. carbonic oxide. RESEARCHES ON CHEMICAL AFFINITY. In Exp. III. a gaseous mixture containing only 64.9 vols. combustible gases to 10 vols. oxygen and only 22.2 vols. carbonic oxide to 10 vols.hydrogen gave equal volumes of the gases consumed. In the following experiments a mixture was used containing Carbonic oxide . . . . 36-70 Hydrogen . . . . . 42-17 Oxygen . . . . . 21.13 100*00 IV. The gas was burned in three portions; the first burned in sunshine at Om*7264 and 22.5' C, gave for the quantities consumed Found. Calculated. Carbonic oxide . . 11.01 1 vol. 10.56 Hydrogen . . . . . 31-25 3 vols. 31.70 -42-26 42.26 V. The second portion burned in the dark at Omg723O and 22.6' C. ,gave Pound. Calculated. Carbonic oxide . . . 10.65 1 vol. 10.57 Hydrogen . . . . . 31-61 3 vols. 31-69 42.26 42.26 VI. The third portion burnt in daylight at Om.3169and 22' C. gave Carbonic oxide . . . 10.71 1 vol.1059 Hydrogen . . . . . 31.55 3 vols. 31.67 -42-26 42-26 VII. The next experiment was made with a mixture containing in 100 vols. Carbonic oxide . . . . 40.12 Hydrogen . . . . . 47.15 Oxygen . . . . . . 12.73 lQO*OO Burned in daylight at 23' C. and Om*7200 it gave for the quan-tities consumed Found. Calculated. Carbonic oxide . . 4.97 1 vol. 5.09 Hydrogen . . . . . 20.49 4 vols. 20.37 c1 -25-46 25.46 PROFESSOR BUNSEN OS VIII. Another mixture of unknown composition gave Found. Calculated. Carbonic oxide . . . 4-95 I vol. 5.07 Hydrogen . . . . . 10.27 2 vols. 10.15 In the mixture with which the Experiments IV. V. and VI. were made the oxygen was to the combustible gases as 10 37.3 and the hydrogen to the carbonic oxide as 10 :8.7.The three experiments show that the voluines of €I and CO consumed were as 3 1 whether the pressure to which the gases were subjected was 01"*7264 or Om.3169,and whether the combustion took place in the dark or in daylight. In Exp. VII. the oxygen was to the combustible gases as 10 (23.5 and the hydrogen to the carbonic oxide as 10:8.5. From this mixture the oxygen took 4 vols. H to 1vol. CO. Lastly in Exp. VIII. the combustion produced 2 vols. vapour of water to 1 vol. carbonic acid. The proportions of hydrogen and carbonic oxide consumed on these several gaseous mixtures correspond to five hydrates of carbonic acid of the following forms 130. 2C0,; HO. CO,; 2 HO. CO,; 3 HO. CO,; 4HO. CO,. Hence it might be imagined that the cause of the combustion taking place in these atomic proportions is to be found in the actual forma- tion of these hydrates.Closer consideration however will show that such a supposition is wholly untenable. It may indeed be easily shown that carbonic acid does not form any definite compound with water-at least at ordinary temperatures. The author has shown (in a research not yet published on the absorption of gases by liquids) that the coefficient of absorption of carbonic acid by water which is 0 8545 at 19.6' C. and 1.4698 at 4.4' C. varies exactly in proportion to the density of the gas at least within the limits observed and consequently exhibits a relation which is totally inconsistent with the formation of a hydrate of carbonic acid.Hence it is impossible to believe that carbonic acid can form as many as four or five definite compounds with water. But even if this sup- position were admissible it would still be contrary to all chemical experience that the compound 2 HO. CO should be formed at the lowest the componnd 3 HO. CO at a higher and the -hydrate 4 HO. CO at the highest temperature. We find on the contrary in all cases hitherto observed that the lower hydrates of acids bear with- out decomposition much higher temperatures than those which contain a larger quantity of water. We cannot therefore suppose that the conipound 4HO. CO, formed at the highest temperature is incapable of existing at a lower temperature and that instead of it only the compounds 3 HO.CO, 2 HO. CO, or HO. CO, are formed. But there is yet another circumstance which speaks most decidedly against this hypothesis. All the known compounds of acids with several RESEARCHES ON CHEMICAL AFFINITY. atoms of water are incapable of existing at very high temperatures whereas these hydrates of carbonic acid if they exist must be formed only at the highest temperatures and must on cooling be again resolved into carbonic acid and water. And even if all these contradictions could be reconciled by the assumption that at the high temperatures at which the combustion of the gases takes place the combining tendencies may be the reverse of those which are observed at lower degrees of heat we should still only encumber ourselves with new difficulties; for there are other phenomena relating to the same point which even this assumption is unable to explain.When oxygen is passed over red-hot charcoal carbonic acid is formed; but this gas by the further action of the charcoal is completely converted into carbonic oxide. If the oxygen gas be replaced by vapour of water the charcoal is likewise oxidized and hydrogen separated. The action does not however proceed to the complete formation of carbonic acid but stops when for every 4 vols. hydrogen separated there have been formed exactly 1vol. carbonic acid and 2 vols. carbonic oxide. A gaseous mixture obtained by this process gave by analysis the following results Found. Calculated. Hydrogen . . . . . 56-52 4 vols. 57.14 Carbonic oxide .. . 28.71 2 , 28.57 Carbonic acid . . . . 14.77 1 vol. 14.29 looooo 100~00 The same composition is found in a similar gaseous mixture analysed more than fifty years ago by Clement and Desormes Hydrogen . . . . . 56.22 Carbonic oxide . . . . 28.96 Carbonic acid . . . . 14.63 Marsh-gas . . . . 0.19 100~00 If now we suppose that the simple atomic relation of the simul- taneously formed products of decomposition results from a eombina- tion formed according to the same proportion we are met by an irreconcilable contradiction. For since the products of oxidation thus formed contain 4 atoms oxygen to 3 atoms carbon we should on the hypothesis just mentioned be obliged to admit that a body having the composition of mesoxalic acid is formed at a red heat and resolved on cooling into carbonic oxide and carbonic acid,-unless indeed we were to take refuge in the still more absurd supposition that an organic compound C3H O? corresponding in composition to the decomposition-products obtained has actually existed at the red heat but has been resolved on cooling into hydrogen carbonic oxide and carbonic acid YROFESSOR BUNSEN ON Especially remarkable is the behaviour of cyanogen when imper- fectly burned.Nitrogen is then set free and carbonic acid and carbonic oxide produced in quantities which hear to one another as the law requires a simple atomic relation. The experiment is diffi- cult inasniuch as the combustion must be made at a temperature low enough to prevent any partial oxidation of the nitrogen.To this end it is necessary to ascertain by preliminary experiments the limits of inflammability of cyanogen and then having made a mixture in proportions near that limit to compress it so far that the limit of inflammability may be just passed and the combustion in the eudi- ometer may take place without sublimation of mercury. In this manner a mixture of cyanogen free oxygen and atniospheric air con- taining in 100 parts Cyanogen . . . . . 18.05 Oxygen . . . . . . 28.87 Nitrogen . . . . . 53.08 100-00 yielded by combustion the following products Nitrogen . . . . . 17.42 3 vols. 17.42 Carbonic oxide . . . 11.93 2 vols. 11-61 Carbonic acid . . . 22-90 4 vols. 23-22 52.25 52-25 Hence it appears that the oxygen unites with the carbon of the cyanogen not to form carbonic acid or carbonic oxide alone but both together and moreover in a simple atomic proportion as if the compound CO .2 CO or C30,had been formed.As it is not possible by altering the proportions of this mixture to attain the limit at which this particular proportion passes into another without incurring the disturbing effect of a simultaneous oxidation of the nitrogen I have been obliged to give up the further prosecution of the experiments with mixtures containing cyanogen. A wider range is afforded by experiments with a mixture of carbonic acid with hydrogen and oxygen in the combustion of which the carbonic acid is exposed at the same time to the reducing action of the hydrogen and the oxidizing action of the oxygen.These experiments demonstrate the remarkable fact that the phenomena of reduction likewise take place in such a manner that the reduced and unreduced portions of the compound bear to each other a simple atomic relation. The contraction which a mixture of carbonic acid and hydrogen suffers by combustion with detonating gas is equal to the volume of the carbonic oxide formed. Moreover as the latter is equal to that of the carbonic acid reduced we have only to deduct the observed contraction from the volume of carbonic acid originally present in the ItESEhRCNES ON CHEMICAL AFFINITY. mixture and the difference will give the portion of carbonic acid which has escaped reduction. A mixture of carbonic acid hydrogen and detonating gas contain- ing 8.52per cent carbonic acid 70.33 hydrogen and 21-15 oxygen yielded in this manner 3 vols.carbonic oxide to 2 vols. carbonic acid just as if 5 atoms CO had been reduced to the compound C 0, or as if the compound 3 CO. 2CO had been formed. The gas remaining after the combustion in the last experiment was again niixed with detonating gas in such proportion as to form a mixture containing 4.41 per cent carbonic oxide 2-96carbonic acid 68.37 hydrogen and 24.26oxygen. The combustion produced an expansion showing that a portion of carbonic oxide had been burnt and converted into carbonic acid; and the quantity of CO thus oxidized was to that which remained unaltered as 1 vol. to 3 vols. corresponding to the compound C 0 or 3 CO CO,.On collecting the results of all these experiments it appears that the reducing and oxidizing actions of oxygen are exerted as if the following conipounds were thereby produced 2 CO. CO,; 3CO. GO,; 3 CO. 2 CO,; HO. 2 CO,; HO. CO,; 2 HO. CO,; 3 HO. 2 CO,; 4 HO. 2 CO,. If the formulae thus determined nearly all of which correspond to unknown compounds could be regarded as the expressims of really existing substances a mode would be found of determining before- hand by experiment the atomic relations of compounds yet unknown. But whatever signification may be attached to these remarkable formulae an6 whatever other relations may lie hid in them they must even now be regarded as the expression of a peculiar mode of action of chemical affinity; and the numbers which enter into them must be distinguished as coeficients of uflnity from the atomic numbers which are coeflcients of combination.Although the results of the preceding investigation must modify considerably our ideas of the mode of action of chemical affinity I refrain for the present from any interpretation of the law above enumerated. It appears to me to be essential to ascertain whether the same law holds good for liquids and to assign the conditions which determine the alteration of the coefficients of affinity. The limits at which these coefficients suddenly pass from one rational proportion to another and at which therefore the force of affinity is as it were in a state of instable equilibrium promise to afford the most important revelations respecting the influence of other forces which are here certainly to be detected in their minutest workings namely of light and heat and likewise of mass and contact.These relations will form the subject of a future Memoir. PROFESSOR BUNSEN ON On the Constitution of Iodide of Nitrogen. By R. nunsen.* That the elements of water are not concerned in the formation of iodide of nitrogen follows from the simple fact that a concentrated solution of iodine in absolute alcohol on being saturated with anhy- drous ammonia yields iodide of nitrogen without any decomposition of the solvent. Hence we may conclude that iodide of nitrogen contains no oxygen but only nitrogen iodine and hydrogen. More-over since in the formation of this compound from iodine and ammonia there is but one secondary product obtained viz.hydriodic acid it follows that the so-called iodide of nitrogen must be a substi-tution-product of ammonia in which the hydrogen is wholly or partially replaced by ammonia viz. 1. NH3+61+xI= N 13+3HI + XI 2. NH,+41 =NH12+2HI 3. NH3+21 =NHJ + HI Either of the compounds 1 2 or 3 might however contain am- monia or hydriodic acid in addition. But it is easily shown that hydriodic acid cannot enter into the composition of iodide of nitrogen ; for this substance dissolves in hydrochloric acid without evolution of gas forming a liquid which contains ammonia and protochloride of iodine but no hydriodic acid. This reaction shows indeed that iodide of nitrogen is a compound of the form NI NHI or NHJ either alone or combined with the elements of ammonia.Which of these two alternatives is the correct one may be easily decided if we can find the atomic proportion which the products of the decomposition of iodide of nitrogen by hydrochloric acid bear to each other. For if ammonia and protochloride of iodine are the only products thus formed the decomposition must take place in one of the following ways 4. N I,+3 HCl=3IC1+NH3 5. NH 12+2HC1=2 ICl+NH 6. NH,I + HC1= ICl+NH Hence it appears that the so-called iodide of nitrogen must be so to speak a nitrile an imide or an amide of iodine according as 3 2 or 1 atom of protochloride of iodine is separated for each atom of ammonia.Similarly we may infer that the separation of 2 atoms of ammonia to 3 atoms of protochloride of iodine would correspond to * Ann. Ch. Pharm. LXXXLV 1. THE CONSTITUTION OF IODIDE OF NITROGEN. the compound NH +NI, and the separation of 2 atoms of ammonia to 1atom of protochloride of iodine to the compound NH,+NH,I. It follows that the composition of iodide of nitrogen may be deter- mined by the products of its decomposition by hydrochloric acid viz. I. By the quantity of ammonia formed. 11. By the composition and quantity of the chloride of iodine. The ammonia is determined as usual by precipitation with chloride of platinum.-To determine the chloride of iodine the following method was used Two equal volumes of the hydrochloric solution of iodide of nitrogen are taken.In the one the iodine is precipitated by chloride of palla-dium after the chloride of iodine has been converted by sulphurous acid into hydrochloric and hydriodic acid. Let the quantity of iodine thus found be i. A known volume of an aqueous solution of sul- phurous acid is then taken in which the quantity of iodine i required to decompose the sulphurous acid has been determined by a prelimi- nary iodometric experiment. To this solution the second portion of the hydrochloric acid solution of the iodide of nitrogen is added and the quantity of iodine i then required to decompose the sulphurous acid then determined by similar means. The quantity of chlorine c contained in the chloride of iodine is then given by the equation C1 -(i -i, -i) =c.I Lastly another equal volume of the hydrochloric acid solution is evaporated over the water-bath till all the chloride of iodine is driven off and the ammouia is determined by precipitation with chloride of platinum. The iodide of nitrogen used for the analysis. was prepared by mixing cold saturated solutions of iodine and ammonia in absolute alcohol. A black powder was precipitated which could be washed with absolute alcohol without suffering the slightest decomposition. The product thus obtained was dissolved while yet moist in dilute hydrochloric acid it dissolved readily and without evolution of gas. From the resulting solution three equal volumes were measured out. The first gave 0.3290 grm.chloroplatinate of ammonium. The second gave 0.1156 grrn. palladium by ignition of the precipitated iodide of palladium. The third was added to a qiiantity of sulphurous acid which according to a preliminary experiment required 241.6 cub. cent. of iodine-solution (containing 0.005 grm. in a cub. cent.) to decompose it and the quantity of iodine still required for that purpose after the addition of the hydrochloric acid solution was found to be 131.4 cub. cent. Hence the quantity of ammonia =0.02508; also i=0-27551; PROFESSOR BWNSEN ON i,=1*2080;i,,=0.6570;whence we find for the products of the decomposition Experiment. Atomic proportion. Ammonia . . . 0.02508 2.04 Iodine . . . . 0.27551 3.00 Chlorine.. . . 0.07701 3.00 that is to say 2 atoms ammonia to 3 atoms protochloride of iodine. Consequently iodide of nitrogen can be nothing else than a compound of ammonia in which the whole of the hydrogen is replaced by iodine with an atom of undecornposed ammonia as expressed by the formula NH,,NI, this will appear more plainly from the following coni- parison of the analytical and calculated results Protochloride of Iodine. t’--A 7Atoms. Calc. Found. Iodide of Nitrogen. _.up-A--Atoms. Calc. 7 Found. C1 1 21.85 21.85 N 1 3.40 3.46 I 1 78.15 78.15 I 3 92-46 92.33 NH 1 4-14 4-21 ___- CII 100.00 100.00 NH,. NI I 00~00 100~00 Results nearly of equal accordance were obtained frotn the analysis of an iodide of nitrogen prepared by the use of less concentrated alcoholic solutions of iodine and ammonia.To determine whether iodide of nitrogen precipitated from aqueous solutions has the same coiriposition as that obtained with alcoholic solutions a dilute solution of iodine in aqua-regia was mixed with ammonia and the resulting precipitate washed as quickly as pos-sible with such a quantity of cold water that the remaining mother- liquor could not contain more than 0.01 milligrm. aminonia. The analysis of the washed precipitate conducted as before led to the formula NH,. 4NI Protochloride of Iodine. Iodide of Nitrogen. --’A. --7 -____ A--7 Atoms. Calc. Found. Atoms. Calc. Found. C1 1 21.85 21.94 N 4 3.51 3.54 I 1 78.15 78.06 I 12 93.43 95-31 NH 1 1-06 1.15 ~ ~___ _. CII 100*00 100.00 NH,.44 NI 100~00 100~00 The great facility with which the ammonio-iodide of nitropi de- composes with separation of iodine and nitrogen when continuously washed with water renders it difficult to decide directly whether the quantity of ammonia actually found in it is really chemically coni- biued or merely mechanically mixed. But an examination of the de- THE CONSTITUTION OF IODIDE OF NITROGEN composition-products obtained from ammonio-iodide of nitrogen by the action of water leads inevitably to the conclusion that the ammonia is really chemically combined. To establish this conclusion it is merely necessary to continue the washing till the greater part of the compound is decomposed with separation of iodine and nitrogen then dissolve the remaining impure iodized compound in hydrochloric acid and examine the solution as before.If by continued washing the compound NI, free from ammonia were at last produced together with free iodine separated as a pro-duct of decomposition the hydrochloric acid solution could not contain more than 1 atom ammonia to 3 atoms chloride of iodine; but if the iodide of nitrogen can only exist in combination with ammonia then however long the washing may have been continued the hydrochloric acid solution will always contain more than 1 atom ammonia to 3 atoms IC1; thus in the former case 21+NI +3 HCl=xI +3 ICl+NH and in the latter z1+XI +zNH3+3 HC1= 21+3 IC1+ NH +ZNH, To decide the question therefore a portion of the iodide of nitrogen used for the analysis was washed for several hours longer with distilled water and then left to stand for a while suspended in water.On the addition of hydrochloric acid a considerably quantity of free iodine remained undissolved The solution which besides ammonia and protochloride of iodine must likewise have contained free iodine gave when analysed as above results corresponding to 1 atom am- monia and 3 atoms protochloride of iodine together with free iodine. We may conclude then that the ammonia forms an essential con- stituent of the so-called iodide of nitrogen and that besides the compound NH .NI, there probably exists another having the composition NH .4 NI,. The manner in which these compounds are formed directly from iodine and ammonia is easily seen from the following equations 2NH3+61=NH,,NI,+3 HI and 4(NH,.NI,) $3 HO=NH, 4N13+3 NH,O. On the other hand their formation from the chloride of iodine obtained by the action of iodine in aqua-regia would be in direct contra- diction to the formula NH, NI, if that chloride were really IC13 as sometimes supposed and not IC1. For the action of ICl on ammonia could not produce NI, but only NI. This discrepancy led the author to suspect that the chloride of iodine obtained in the manner just mentioned is not really a terchloride but a protochloride,- ON THE CONSTITUTION OF IODIDE OF NITROGEN. a supposition which has been fully confirmed by experiments made in the author’s laboratory by Mr. Cohn. The formation of ammonio-iodide of nitrogen by the action of ammonia on chloride of iodine niay therefore be expressed by the following equation 2NH3+31Cl=NH,.N13+3 HCl.The view here given of this compound likewise gives an easy account of the changes which take place when it explodes. The first products of the explosive decomposition are nitrogen and hydri- odic acid NH,.NI3=3HI+2N; but the latter at the higher temperature which accompanies the decomposition must be resolved for the greater part into iodine and hydrogen; while another part of the acid must unite with another part of the compound to form iodide of ammonium and thereby set free quantities of iodine and nitrogen equivalent to this ammonia. PAGES MISSING FROM 95-96