Moreover, it is probable that all the beetroots which are treated in the Sugar Manufactory of Waghaüsel do not contain iodine, seeing that this manufactory, which is fitted up on an extensive scale, operates annually on 50,000,000 kilogrammes (45,000 tons) of beet-roots supplied by 142 different communes, situated in a very extensive radius. Such varied sources lead one to think that the presence of iodine should be, so to speak, entirely local, if this body has the origin I have indicated. To elucidate the question, it would be necessary to have at disposal a very considerable average sample of beet-root, and, moreover, samples of beet-root cultivated in such and such localities, which should be stated. An endeavor should likewise be made to estimate the iodine and thus to ascertain whether this body is in sufficiently important proportion to be extracted on the large scale: I intend to examine this further. ON THE ACTION OF BASES ON BY SENOR ALVARO REYNOSO. IT is generally considered that, when a salt whose oxide is insoluble is treated by an alkaline solution, this oxide is precipitated without being redissolved; at any rate that in the free state it is not soluble in an excess of alkali with which the salt which contains it has been put in contact. The solution of arsenite of copper is blue, and decomposes after a certain time into protoxide of copper, which precipitates, whilst the arsenite of potassa passes into the state of arseniate. The decomposition of the solution of arsenite of mercury is almost instantaneous. The solution of silver is colorless, and is very slowly decomposed, precipitating the silver as a black powder. This solution does not precipitate with chloride of sodium; on the contrary, the chloride of silver, which is insoluble in potassa, very readily dissolves in it when arsenite of potassa is added. I profited by these two properties of arsenite of silver to effect the reduction of the salts of palladium by means of silver. The following is the mode of experimenting :-chloride of palladium, to which arsenite of potassa has been previously added, is poured into the solution of arsenite of silver in potassa. A precipitate of a black powder is speedily formed, which contains metallic silver and palladium. Chloride of platinum is reduced much more quickly than chloride of palladium. It is to be remarked that, in these reactions, the arsenite of silver is dissolved sooner than when it is alone. The arsenites of cobalt, nickel and uranium are completely dissolved in potassa and soda only in the nascent state. To that end, arsenite of potassa with a great excess of potassa must be used, and the solution must be poured into a soluble salt of cobalt, nickel or uranium. These reactions may easily be comprehended, by admitting that the arsenite of potassa may form, with the combination of potassa with these oxides, a soluble double salt, and that it is under this influence that their solution is determined. When potassa is made to act on an insoluble salt whose oxide is itself insoluble in an excess of potassa, it can be dissolved only by the for In studying the action of potassa and soda on the arsenites, I have been led to observe certain facts, which, if they are not precisely contrary to the general rule which I have just quoted, prove, at least, that this phenomenon of precipitation is sometimes intimately connected with the nature of the supernatant salt in which the precipitate exists; so that, in certain cases, this salt might determine the solubility of the oxide.mation of a double salt. Thus, for example, Thus, for example, the oxides of copper, uranium, cobalt, nickel, silver and mercury, and sesquioxide of iron, being insoluble in potassa and soda, when potassa or soda is poured into the arsenites of these bases, there should be simply a precipitation of insoluble oxide, and formation of arsenite of potassa or soda, without an excess of alkali exerting any action on the oxide. However, I have found that the arsenites of all these oxides are completely soluble in potassa, although in the free state these oxides are insoluble in it. I have proved that arsenite of lead is insoluble in potassa. The proof that these reactions depend on the nature of the salt formed is, that the arsenite of lead, which is insoluble in potassa, is soluble in soda. When potassa is poured into an insoluble salt, it removes the acid, and the oxide, set at liberty, will remain without action on the salt formed, for it is insoluble; but if an excess of potassa be added, and if the oxide be soluble in it, then, if the combination of this oxide with potassa cannot combine with the supernatant salt, we shall have two soluble salts together, which, being capable of forming an insoluble salt, by their decomposition will regenerate the original salts. However, this case is the rarest, for experience has proved that almost all the salts of potassa have the property of forming a soluble double salt with the oxides soluble in potassa. For ammonia, I proved the solution of arsenite of sesquioxide of iron. In conclusion, there may be four cases in the action of an excess of potassa on insoluble salts. 1. Certain oxides soluble in the free state in potassa, and forming soluble double salts with all the salts of potassa, solution may be observed in all circumstances. 2. At other times, oxides soluble in potassa in the free state, will form salts insoluble in potassa when the acid is of a nature not to form a soluble double salt with the combination of the oxide with potassa. 3. Other oxides, insoluble in the free state, in potassa, will nevertheless sometimes form a soluble double salt, and, consequently, dissolve when put in contact with potassa in the nascent state, in presence of the salt of potassa with which they can combine. 4. When the oxide is insoluble in the alkalis, it is precipitated, without redissolving, when the salt which contains it is treated by an excess of alkaline base. The latter case occurs when the precipitated oxide cannot form a soluble double salt. ON ARIDIUM, A NEW METAL.* A PAPER by M. Ullgren has been recently its oxides great resemblance to iron, it has been named aridium. In some experiments made with the view of detecting the presence of phosphorus in the bar iron of Oernstolos iron ores, the author found that the solution of iron obtained behaved in several respects differently towards reagents from one of iron only. Subsequently, in an examination of the chrome iron of Röros, he found that the peroxide of iron separated from it behaved like that in the first-named solution. The powdered chrome ore was digested with hydrochloric acid, the greenish-yellow solution evaporated to dryness, the silica separated in the usual manner, and sulphuretted hydrogen passed through the solution to perfect saturation. A very small quantity *Oversigt. af. Kongl. Vetensk. Akad. Förhandlinger, No. 3, 1850. of a greyish-yellow precipitate was obtained, consisting chiefly of sulphur. In order, however, to be certain of separating every metallic sulphuret insoluble in an acid liquid, the solution was neutralised with caustic potassa, mixed with sulphuret of potassium, then enough hydrochloric acid was added to dissolve the black precipitate that was formed. There was an inconsiderable pale yellow residue, and the solution was of a beautiful green color, proceeding principally from the oxide of chromium extracted from the chrome iron ore by the hydrochloric acid. The solution was then heated with chlorate of potassa and an excess of hydrochloric acid, and then precipitated with potassa at a boiling temperature. The alkaline liquid was yellow, and contained chromic acid and alumina; the precipitate was brownish-yellow; it was dried, rubbed to powder, and fused in a platinum crucible with a readily fusible flux and chlorate of potassa. When the fused mass was exhausted with water, only chromic acid and some alumina could be detected in the yellow solution. The presence of the latter induced the author again to dissolve the livercolored residue, in hydrochloric acid, to precipitate again with caustic potassa, and wash with boiling water. The washed brown residue was then dissolved in hydrochloric acid, the solution mixed with a sufficient quantity of acetate of soda, diluted and boiled. A light reddish-brown pulverulent precipitate was obtained, not bulky, flocculent or brown like peroxide of iron; manganese, lime, magnesia and a trace of zinc remained in solution. The precipitate was now dissolved in hydrochloric acid, and the solution saturated with caustic ammonia. The precipitate produced formed blackishbrown lumps, which when dry did not present a vitreous, but an earthy fracture. This precipitate was then treated in the following manner :-A portion was dissolved in hydrochloric acid, and the acid expelled by ebullition with an accurately measured quantity of sulphuric acid, and evaporated to dryness. The residue was a whitishyellow mass, interspersed with crystalline scales, still moist with the excess of sulIt was dissolved in alcohol of phuric acid. 0.86 spec. grav., and 6 times the bulk of ether added to it. became milky, and in the course of an hour The liquid instantly the small eliminated drops collected in a thick syrup at the bottom of the vessel. The clear decanted liquid was again rendered turbid by the addition of ether. pelling the ether and alcohol, a thick liquid remained, in which floated some blackishbrown flakes, not, as at first supposed, con After ex sisting of an organic substance produced by the action of sulphuric acid on alcohol; for when burnt, they became greyish white, and gave with borax and microcosmic salt colorless beads, and a yellowish-grey opalescent bead with soda upon platinum wire. The liquid separated from these brown flakes deposited, on slow evaporation, after forty-eight hours, some small crystals cohering to verrucous masses, which were rinsed with alcohol, in which they are very sparingly soluble. These crystals are the sulphate of the peroxide of aridium. This III. When sulphuretted hydrogen was passed through the solution of this metal, the oxide was reduced to protoxide. After expelling the excess of sulphuretted hydrogen, it was precipitated of a greyish-white color by ammonia; but this precipitate immediately became light brown, and not through green into brown as with protoxide of iron. IV. The fresh solution of the protoxide is precipitated by ferrocyanide of potassium of a pale whitish-green color, which gradually changes into dark green, and afterwards becomes blueish. If an excess of ammonia is poured over it it becomes of a beautiful blue; but this color gradually disappears, and it finally turns greyish blue. V. A solution of the protoxide of aridium is not precipitated by an infusion of galls. Acetate of soda gives a pale red precipitate. VII. A solution of the peroxide of aridium gives a dark blue precipitate with ferrocyanide of potassium; but an excess of the precipitate changes the color into a dirty blueish green. Cerium give a white precipitate. Another portion of the same peroxide of iron, which had been used in the preceding examination was now heated to redness in a current of hydrogen until no more water was given off; the residue was treated with dilute nitric acid, in which a portion dissolved with disengagement of nitric oxide, which, however, soon ceased, when a black, VI. A solution of the peroxide of aridium somewhat brownish powder was left. does not strike a black, but a dark indigopowder was magnetic, but the solution blue color with an infusion of galls, and behaved like one of pure peroxide of iron. furnishes upon the addition of acetate of The powder was certainly an oxide, as it soda a brownish-violet precipitate. Neither dissolved in hydrochloric acid without dis-iron nor cerium behave in this manner. engagement of gas. It was then packed into a charcoal crucible, covered with cyanide of potassa, and heated in the forge furnace. The powder caked together by this treatment, acquired an iron-grey color, interspersed with some small fused grey metallic granules. Dilute nitric acid dissolved a small portion with evolution of gas, but it soon ceased, and left a residue which dissolved no further in it. The portion dissolved by the nitric acid, in this and the preceding case, after the treatment with hydrogen, was peroxide of iron. The insoluble portion was now no longer magnetic, and dissolved in concentrated hydrochloric acid without disengagement of gas. This residue, therefore, like the protoxide of uranium, is a lower oxide of aridium, which cannot be further reduced in the charcoal crucible. The following is, as far as yet ascertained, the behavior of the oxide in question which justifies its being regarded as the oxide of a new metal : I. It dissolves in hydrochloric acid without disengagement of chlorine, and furnishes on evaporation at a gentle heat, a lemonyellow deliquescent residue, which cannot be made to crystallise. It differs in this respect from the oxides of iron and cerium. II. It gives a compound with sulphuric acid, which yields a colorless solution with water, differing from the persulphate of iron, at least in the presence of free acid. On ignition, this sulphate left a reddishbrown powder, which appeared under the microscope as small indistinct transparent crystals of a beautiful red color. VIII. A solution of oxide of aridium is colored blueish green by the ferridcyanide of potassium, and deposits in the course of an hour, in the dark, a precipitate of the same color. A solution of peroxide of iron is colored brown; cerium is not precipitated. IX. A solution of the peroxide of aridium is not precipitated, like a solution of iron, of a deep blood red by acetate of soda, but dark yellowish brown. X. A solution of the peroxide of aridium strikes a deep red color with sulphocyanide of potassium, like a solution of the peroxide of iron; but in the case of iron the color disappears with an excess of acid, whilst with the peroxide of aridium it remains, even with a large excess of acid. XI. A solution of the peroxide of aridium gives a light brownish-yellow precipitate and a yellow solution with carbonate of soda; peroxide of iron, on the contrary, gives a brownish-red precipitate, which also dissolves with a red color. XII. The alkaline sulphurets produce a blackish-green precipitate, and the solution continues long green. The precipitate dissolves readily in dilute nitric acid. XIII. Solutions of the oxide of aridium furnish with caustic alkalies precipitates like those produced in solutions of the peroxide of iron, only they are somewhat yellower, and more earthy when dried. After ignition, the powder is greyish brown, and not so red as the peroxide of iron. XIV. Before the blowpipe, oxide of aridium gives with borax, on platinum wire, in the outer flame, a yellow bead which becomes colorless on cooling with small quantities. In larger quantities, the bead is of a brownish red; on cooling, yellow and opalescent, but not as with cerium. In the inner flame, the bead is colored of a light green by small quantities, and becomes colorless on cooling; with a larger quantity, the bead is of a beautiful green while hot; the purity of the color decreased as it cooled. With microcosmic salt and strong saturation, the bead while hot was dark red in the outer flame, and perfectly colorless when cold. In the inner flame, the bead with a small quantity was colorless; with a large quantity slightly brown when cold. The mass fused with soda upon charcoal to a glass, which was absorbed by the charcoal, but did not furnish any metallic particles on being subsequently triturated in a mortar. On platinum wire with soda, a reddish-brown transparent glass was obtained while hot, which on cooling became spotted with brown. In the inner flame, a glass was formed, which remained perfectly colorless. and in which no precipitate was perceptible. On heating the bead in the outer flame, the previous reaction appeared. THE DECOMPOSITION OF CHLORIDE OF SODIUM BY ACETIC ACID IN THE PRESENCE OF ALBUMEN, OR THE COAGULATION OF THE ALBUMEN OF THE SERUM IN THE PRESENCE OF ACETIC ACID AND A CERTAIN AMOUNT OF CHLORIDE OF SODIUM.* BY DR. E. A. PARKES, PROFESSOR OF CLINICAL MEDICINE IN UNIVERSITY COLLEGE, AND PHYSICIAN TO UNI VERSITY COLLEGE HOSPITAL. I HAVE been unable to find any notice of some facts which I have lately observed, and which are of interest in a chemical point of view, and possibly also may have physiological and pathological applications. If the undiluted serum of the blood be strongly acidified with acetic acid, no change results, or a very slight haze is produced. If large fragments of chloride of sodium are now dropped into this fluid, the following changes occur. Almost immediately the sharp angles of the salt disappear, the fragment increases in size, and becomes *Medical Times, July 27th, 1850. rounded in form, from the deposit upon its surface of a coating of albumen. Slight agitation dissolves both the coagulum and the salt, and the serum becomes as before, perfectly clear. If the particles of salt are very small, the solution occurs so rapidly, that the albuminous deposit can scarcely be observed. The addition of a little more salt re-induces the same phenomena of deposit of albumen and subsequent re-solution. After a certain amount of salt has been added, the serum becomes incapable of dissolving the albuminous precipitate; and this condition of things occurs, provided the acidity be considerable, when the percentage of the chloride of sodium is very moderate. The albumen thus precipitated is not affected by acetic acid, or by caustic potassa, added at once to the solution, but is soluble in water. If chloride of sodium be now added to saturation, the whole of the albumen is thrown down, and the liquid, which can be filtered off the precipitate, gives no indication of albumen, or the very merest trace. The filtering is more readily accomplished, if the fluid be diluted by adding a little strong solution of chloride of sodium, or, what is the same thing, a little water, not sufficient to dissolve the excess of chloride of sodium which has been added. The explanation of these changes appears to be, either that in the first place the presence of another acid permits the hydrochloric acid to manifest the strong affinity it has for albumen, which consequently coagulates round each particle of salt; and, secondly, that the compound thus resulting, which is so soluble in water, is perfectly insoluble in a moderately strong solution of chloride of sodium, or it may be supposed that the combination of acetic acid and albumen, which is soluble in water (like the combinations, under certain conditions, of hydrochloric and nitric acids with albumen), is insoluble in solution of chloride of sodium of a certain concentration. The first explanation appears more probable, but some experiments, which need not be detailed now, on the action of acetic acid on serum, apart altogether from the influence of hydrochloric acid, or of chloride of sodium, support, in some measure, the last supposition. The rapidity and perfection with which these changes occur depend upon the strength of the acid, and upon the quantity of chloride of sodium, and possibly, also, may be affected by the percentage of albumen; although am not at present able to speak perfectly on this last point. The amount of foreign acid present seems to be a very important point. If the quantity of acetic acid which is added, be so small as to give a just perceptible acid reaction, a good deal of salt dissolves without any precipitate; and it is not till a considerable amount has been added that the deposit occurs, and then apparently this is impartial and imperfect only; whereas, if the acetic acid be added in larger quantity, the deposit occurs at once, and the quantity of chloride of sodium necessary to be added is inconsiderable. Thus, some limpid serum, which analysis in the ordinary way proved to contain 66 per 1000 of coagulable matter, insoluble in alcohol and water, (after coagulation), being very feebly acidulated with acetic acid, nearly 24 per cent. of common salt was added before the liquid became very turbid, and then the turbidity, though manifestly greater than that which would have been produced by the salt alone,* was infinitely less than was produced by sharply acidulating the same serum, and adding only 5 per cent. of chloride of sodium. It would, therefore, appear that, though a feeble acid may, under certain circumstances, cause the coagulation of the albumen, yet that a strong acid does so much more perfectly. The Chloride of sodium is not the only salt which causes, under the circumstances now noted, the coagulation of albumen. chloride of potassium, as might be supposed, acts in the same way, so do the sulphates of potash and soda, the nitrate of soda, the sulphate of magnesia, and probably other salts. On the contrary, no precipitate can be obtained with acetate of potash and acetic acid. Other acids may be substituted for the acetic. Thus hydrochloric acid added to moderate acidity gives no precipitate; or, according to the strength of the acid, gives a precipitate which is redissolved, the addition of chloride of sodium immediately producing the albuminous deposit. It is an interesting point that the common phosphate of soda, (2 atoms of fixed base) not only gives no precipitate by itself, or with acetic acid, but appears to a certain extent to dissolve that given by chloride of sodium. Thus, if phosphate of soda be first added to saturation,* and then acetic acid and the chloride of sodium, the proportion of the latter necessary for complete precipitation is greater than when no phosphate is present; yet no amount of phosphate of soda will prevent the coagulation when the chloride of sodium reaches a certain amount. *The effect of chloride of sodium, and some other neutral salts, in producing, (when added to saturation) a white precipitate in the serum of blood, was first no- Whether these or analogous chemical ticed by Dr. Buchanan, of Glasgow.- changes occur in the animal system, and, (Proceedings of the Glasgow Phil. Society, if so, under what conditions, is a point on March, 1845). The precipitate thus pro- which it would be hazardous to express at duced is comparatively small in amount. present any opinion. It is very evident Dr. Buchanan named this matter provis- that the amount of chloride of sodium ionally "pabulin," from the notion that normally present in serum (viz., from 3 to it was immediately derived from food; but 6 per 1000 parts) would not permit depofrom an experiment on himself he after-sition from this cause even in the presence wards concluded that it existed also in the serum, drawn after twenty-four hours' fasting. Although I have not yet succeeded in absolutely proving it, I think this substance is albumen; and, if so, it affords another instance of the remarkable influence of chloride of sodium on a strong solution of albumen such as exists in serum. A portion of albumen seems to be deposited when chloride of sodium is added in excess. A little water dissolves the precipitate, and the saturation of this water with salt again precipitates it. Some other salts, as sulphate of soda, act even more powerfully in this -way. + These rough numbers are, of course, merely given as examples, or approximative averages, to indicate the point in question. In the serum in question the amount of chloride of sodium normally existent in it was not determined, as the experiment was one merely of comparison. of the strongest acids; and that, if serum containing the whole of its salts and albumen were to exude into the tissues of the body which have so strong an acid reaction, and, although such normal acidity were heightened by the presence of a foreign acid, (as very possibly may be the case in various diseases), yet no coagulation of albumen, in the manner here supposed, could occur, so long as the serum remained in its ordinary state of dilution. At least this is to be concluded from such elements of the problem as are at present known to us. Yet it is equally evident, that, if such exuded serum could undergo concentration in any way, then (in spite of the dissolving influence of the phosphate of soda), with a rapidity and perfection proportioned to the * In all these experiments it is necessary to avoid adding water, as water itself produces specific changes on the albumen. |