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duced, similar to that produced with sodic hydroxide. This was filtered off from the solution of baryta water and rapidly washed out with hot water. During the process of filtration the surface of the liquid on the filter was carefully protected from the influence of the air by a perforated cover which was connected with a tube containing potassic hydroxide. After

all baryta had been washed away, the residue was boiled with alcohol, and again rapidly filtered in order to remove any uncombined C,,,,O,. It was then dried and analyzed with the following results:

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0-1904 grams of the substance gave 01085 grams BaSO4= 0.065798 grams Ba.

Calculated.

Found.

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The formula is therefore C,,H,,BaO+H2O. The compound is very stable. As was seen above it can be boiled with alcohol or water without undergoing decomposition. It is, however, decomposed by acids just as the sodium-compound is, the substance C,,H,,O, being precipitated.

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[blocks in formation]

If lime-water is used instead of baryta-water, a precipitate is produced, which is, however, of a beautiful lemon-yellow color. This was purified in the same manner as the barium-compound. The analysis gave the following numbers:

0.2172 grams of the substance gave 0·0937 grams CaSO4=0·0275 grams Ca.

[blocks in formation]

Found.

Calculated.

[blocks in formation]

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Magnesium-Compound.—When the body C,,H,,O, is boiled in water with magnesia, a purple compound is produced, which resembles the above described compounds in many respects. This is probably the same compound that is mentioned by Wislicenus as having been prepared in another way.

We have here then a series of peculiar metallic compounds, which are not salts in the usual acceptation of that term. The substance C,,H,O, is not an acid; at least it does not contain the group COOй, for it is entirely unaffected by the alkaline carbonates, and, its metallic compounds are themselves

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decomposed by carbon dioxide. Wislicenus proposes the formula

CH.CO.CH.CO.0.C,H,

CH, COCH.CO.O.C,H.

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for the original compound, according to which it is ethyl succinylsuccinate, a derivative of succinylsuccinic acid. The metallic compounds are explained by supposing the hydrogen atoms of the groups CH to be replaced by the metals, the hydrogen in these groups having a somewhat acid character. It seems to me that the great stability of the ether which we have above recognized speaks against this formula. Most acids, which consist of atoms grouped in the manner indicated by the above formula, are decomposed by boiling with barytawater, whereas we have seen that this substance may be boiled with baryta-water without undergoing decomposition. It is true that we know very little concerning bibasic acids of this structure, and it is possible that what is true of the monobasic acids is only partially true of the bibasic. Be this as it may, it is certain that the experiments thus far published will not permit the positive conclusion that the above formula is the true one, and further investigations would be called for whether the formula is correct or not.

3. Action of phosphoric Chloride upon the body C,,H,,O..

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With the hope of learning something more definite concerning the nature of the oxygen-atoms contained in the substance under examination, I next undertook the study of the action of phosphoric chloride upon it. At first I employed two molecules of the chloride to one molecule of the substance. When the two are brought together in a dry vessel, no action ensues until heat is applied. If the mass is very gently heated, the substance C,,H,,O, melts, and immediately reaction commences, and continues then without the further aid of heat, until the contents of the retort form a clear, homogeneous liquid. The reaction is accompanied by an evolution of chlorhydric acid, the amount of which, however, was such as to leave me in doubt whether this was a necessary product of the reaction, or was formed from the secondary decomposition of the phosphorus compound which distilled over. The oxichloride of phosphorus was distilled off by gentle heat, and the oil in the retort then treated with water. Decomposition soon began and there resulted a solid, insoluble product. On examination this proved to be the original substance C,,H,,O,. As the amount of this product was comparatively considerable, I at once concluded that a chloride had been formed by the first reaction which by its decomposition with water yielded the

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mother-substance. This conclusion proved subsequently to be erroneous, in such a way as to show that the first error in judgment was partially excusable. In a second series of experiments, I employed four molecules of the chloride to one molecule of the substance, and thus reached new results. The same phenomena accompanied the reaction, that were noticed in the case already described. The direct product was a clear, yellow oil. This was treated with a little cold water. At first the oil simply fell to the bottom of the vessel, but in a short time decomposition commenced, and gradually the oil disappeared, a solid product remaining in its stead. On being filtered off and examined, the solid product proved to be a new acid, comparatively easily soluble in water. In the filtrate there was also contained a considerable quantity of the new substance, which was extracted by shaking with ether. The new acid crystallizes out of the concentrated aqueous solution in lamine which are colored yellow. In alcohol it is exceedingly easily soluble. It dissolves in a little potassic carbonate, and is precipitated from the solution on the addition of a few drops of chlorhydric acid.

As this product is easily soluble in water, it is plain that it escaped me in the first experiment, by remaining dissolved in the water which served for the decomposition of the chloride, a sufficient quantity of water having been employed to dissolve the whole of the product, if the conversion of the substance C,,H,,O, into the chloride had been complete. That which was really found in the first experiment was simply a part of the original substance, which had not been acted upon by the chloride of phosphorus.

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If we attempt to distil the chloride for the purpose of purification the mass is completely carbonized. A few drops of a colorless liquid boiling at a high temperature pass over, but the quantity of this liquid is too small to admit of an examination. It is decomposed by water, and the product is solid. It was impossible to determine the nature of the solid, owing to the small quantity obtained. It is not probable that it was succinic acid, for, in that case, the chloride from which it was obtained would have become solid at a low temperature, whereas it remained liquid even when cooled down to 0°.

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If the product of the action of phosphoric chloride on the substance C,,H,,O, is heated for some time, it gradually becomes solid, or nearly so, and then has the appearance of a translucent resin. I analyzed this compound, but the numbers obtained did not agree in different analyses It appears, thus, that condensation and decomposition of the chloride are caused by heat.

As the most important result of these experiments with

phosphoric chloride, then, we see that, if four molecules of the chloride are caused to act upon one molecule of the substance C,,H, O., a liquid chloride is formed which is decomposed by water yielding a new acid. I have not yet studied this new acid, and can, therefore, not state in what manner it is derived from the original substance. As it can apparently be prepared in any desirable quantity with comparatively little trouble, its examination will probably give interesting and positive results.

In addition to the results already recounted, I will mention the following:

1. Acetyl chloride exerts no influence upon the substance. C,,H,,O. It simply dissolves it when gentle heat is applied, but, on cooling, the unchanged substance crystallizes out. This result could be anticipated with considerable certainty, as the presence of alcoholic hydroxyl in the substance was not at all probable. Still the experiment was necessary to prove the fact, no matter how probable it might appear.

2. Ammonia does not act upon the substance either in aqueous or alcoholic solution. v. Fehling (loc. cit.) states that with ammonia the body yielded a bright yellow compound crystallizing in needles. I endeavored in vain to obtain such a compound. I first boiled the substance with very strong aqueous ammonia; it remained unchanged. I then conducted dried ammonia gas into an alcoholic solution of the substance. The solution turned deep yellow in color, but I was unable to extract from it anything save the original substance. This indeed, sometimes crystallizes in needles-a fact which may have misled v. Fehling. By analogy we should expect the formation of a compound with ammonia corresponding to the metallic compound described above. It is possible that some change in the conditions may lead to its formation.

3. Hydrogen in the nascent state (from tin and chlorhydric acid) does not act upon the substance. If the group CO is present, it is difficult to see why this should not be converted into the secondary alcohol group CH.OH by the action of hydrogen.

4. A solution of potassic permanganate, as well as dilute nitric acid, oxidize the substance very slowly. The products of the oxidation I have not yet examined. In connection with the oxidation by means of potassic permanganate a peculiar phenomenon was noticed which deserves mention. I have stated that the oxidation took place slowly; the product was not an acid, so that the manganic oxide formed was precipitated; but, further, the substance oxidized was insoluble in water, so that the manganic oxide, being produced in contact with the

faces of the insoluble crystals, was deposited in even layers upon them, forming thus a complete envelope, and giving a genuine pseudomorph. I was at first deceived by this strange pseudomorph, believing it to be the product of the oxidation. It was insoluble in water, and appeared to be insoluble in alcohol. I found, however, afterward, that the alcohol dissolved the central portions of the pseudomorphs leaving the envelopes unchanged in form.

5. The substance was heated with water at 150° in a sealed tube. At this temperature decomposition took place, but not at a lower temperature. The products of the reaction were alcohol, and a solid, white crystalline substance which conducted itself in some respects like succinic acid. The alcohol was detected by placing the whole product in a flask and distilling with water. The distillate was tested by Lieben's reaction* for the formation of iodoform.

The experiments which have thus been described do not suffice to enable us to judge positively in regard to the structure of the substance under investigation. I have stated above the view held by Wislicenus, and also my objections to this view. It remains yet to be decided whether my objections are well founded, and this can be done only by the aid of new experi

ments.

No. V. On the action of Ozone on Carbon Monoxide; by IRA REMSEN and MASE S. SOUTHWORTH.

One of the most remarkable examples of so-called nonsaturated compounds is carbon monoxide. If we accept the hypothesis of constant valence, the compound CO must possess free affinities, or, as some chemists believe, the two affinities of the carbon-atom, which are not saturated by the oxygen atom, must exercise an influence upon each other. We can not explain this case by assuming that two carbon-atoms are joined together by two affinities each, for we know that the formula of carbon monoxide is CO, and not C, O, or a higher multiple, and, accepting this formula, it is plain that we cannot assume a double union of carbon atoms in the compound.

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If, on the other hand, we accept the hypothesis of variable valence, believing that the valence of an element depends upon circumstances, we shall look in vain for circumstances which, in the one case, can cause the bivalence, in the other the quadrivalence, of the carbon-atom. A difference in temperature certainly does not cause the difference in valence. The atom

* Annalen der Chemie, Suppl. VII, 218.

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