May not the exterior secondary rings, thrown off by the planets, have been at too great a distance to form stable satellites? and in such case would not the detached portions of matter revolve round the sun in very eccentric orbits, the degree of eccentricity depending on the direction of their motion at the epochs of separation from the secondary system? If so, the approximate coincidence between the periods of planets and comets would follow as a consequence."

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Indiana University, Bloomington, Indiana, March 29, 1864.

ART. II.-Abstract of Prof. Meissner's Researches on Oxygen, Ozone, and Antozone; by S. W. JOHNSON.

[Concluded from vol. xxxvii, p. 335.]

THE 2d Section, entitled The Polarization of Oxygen in the Act of Combustion, opens with an examination of the products of the slow oxydation of phosphorus. The white fumes which are always formed in this process have been the subject of much speculation. Schönbein observed that the fumes appear only in moist air. He once (1848) held them to consist merely of phosphorous acid, formed by the contact of vapor of phosphorus with oxygen. Afterward, he noticed that they do not readily disappear upon agitating with water, and since dry PO, absorbs water with great avidity, he assumed in the fumes the existence of an insoluble PO,, isomeric with the ordinary acid. Williamson thought the cloud to consist of PO,, the last result of the action of ozone on vapor of phosphorus. Osann, at first, denied the existence of any of the oxyds of phosphorus in the fumes on account of the permanence of the latter, as they may be passed through water, potassa lye, oil of vitriol, nitric acid, and solutions of nitrate of silver, arsenious acid, protosulphate of iron, and iodid of potassium, without perceptible change. Finding, however, evidence of the presence of PO, in the water over which the cloud had been allowed to stand until it disap

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15 The perturbation of such portions of nebulous matter was the "general cause" to which the writer referred in his paper on the mean distances of the periodic comets, read before the American Association in 1858. Nearly the same idea was suggested in a letter dated May, 1863, by DAVID TROWBRIDGE, Esq., of Perry City, N. Y. At that time, Mr. T. knew nothing of the above-mentioned paper on the subject, so that the hypothesis was with him entirely original. He remarks:

The breaking up of the ring might detach small portions that would not unite with the parent mass. The eccentricity would depend on the angle of projection. See Math. Monthly, vol. ii, p. 160, Art. 18, Equation (58).

"This being true, the mean distances of the comets should coincide approximately with the mean distances of the planets. I think we should look for the larger comets to have the longer periods of revolution, because larger amounts would be thrown from the large rings in a less condensed state."

peared, Osann adopted Schönbein's idea of the existence of two modifications of phosphorous acid.

Quite recently, as our readers are aware, Schönbein has given up his former opinions and now maintains that the cloud consists essentially of nitrite of ammonia. The objection with which he now argues the impossibility of its being constituted of phosphorous acid, viz: its insolubility in water, he does not appear to notice is equally fatal to this new idea.

Meissner, on subjecting a stream of air that had passed over moist phosphorus to the tests already detailed, obtained with it all the phenomena which characterize antozone. Thus, when the air is washed with solution of iodid of potassium, whereby it is deozonized and thereupon is made to pass through water, it emerges from the latter as a thick cloud. The cloud vanishes of itself after the lapse of about half an hour and cannot then be reproduced, though it is scarcely diminished by agitation for a short time with water; when subjected to drying agents, it disappears, but is formed again on renewed contact with water, if too much time is not allowed to transpire.

In the air which is acted on by phosphorus there thus appear both ozone and antozone, as in the case of electrized air; but the relative proportions of the two allotropic oxygens, in the air which has been conducted over moist phosphorus, are very different from what exist in electrized air. In the case of air exposed to moist phosphorus, the quantity of ozone is much less than in electrized air. This is due to the fact that the phosphorus itself consumes a large share of the ozone. Meissner obtained in his experiments much more antozone by phosphorus than by electricity, as measured by the density and ready appearance of the cloud.

While passage of the electrized air through strong solution of KI removed the cloud, by absorbing its moisture, it was found, as Osann had observed, that the phosphorus cloud was scarcely affected by bubbling through oil-of-vitriol. It is only needful, however, to prolong or increase contact between these drying agents and the cloud in order to cause its disappearance.

When the phosphorus cloud traverses a strongly heated glass tube, it disappears. The same is true when it is brought into intimate contact with PbO, or MnO,.

By diminishing to a certain point the quantity of oxygen in a gaseous mixture, we may have the result, that when it streams over moist phosphorus, all the ozone produced is again consumed, and only antozone (of the two active forms of oxygen) remains in the air.

The complete identity of the cloud that forms when phosphorus slowly oxydizes in moist air, with that produced when electrized air emerges from water, is thus established.

Long ago, Schönbein observed that HO, appears when air is acted upon by moist phosphorus. This substance Meissner finds to be more largely and easily obtainable from air exposed to phosphorus than from electrized air. This he concludes to depend upon the corresponding difference in the relative development of antozone in the two instances. On the other hand, when the air from phosphorus passes through solution of KI, it yields to subsequent wash-waters but minute traces of iodic acid, while from electrized air this substance may be collected in considerable quantity. This fact is again to be ascribed to the small amount of ozone in the former as compared with the latter case. In water which had been traversed by the air from moist phosphorus, previously deozonized by means of KI, no nitrous acid and no ammonia could be detected. Of the latter, at least only those minute traces everywhere recognizable with potassioiodid of mercury, were observed.

The water, thus containing HO, but free from NO, and NH,, contained PÓ,. When the antozone cloud produced by phosphorus is received in a perfectly dry and clean vessel, and there allowed to resolve into ordinary oxygen and water, the latter, which deposits as a dew on the walls of the vessel, has an acid reaction, which is not attributable to the minute trace of 10, it contains, but proceeds from PO,, whose presence is readily made out by the usual tests.

Even when the antozone cloud is made to bubble through potash-lye, it still retains a trace of PO,. It is, in fact, the property of the antozone cloud to transport suspended matters, which accounts for the finding of PO, and PO, by other ob servers. It is of course only needful to procure sufficient contact between the antozone cloud and water, or an alkali, to arrest these substances entirely.

When the air clouded by contact with moist phosphorus is made to pass direct through water for a long time, the latter acquires an acid reaction from PO,. After the PO, is removed, or neutralized, HO, may be detected by aid of KI, starch and FeO SO,. Nitric acid Meissner found but very rarely and then in but very minute traces.' It appears that while in electrized air nitrogen is oxydized by the ozone to a considerable extent, in air streaming over phosphorus the phosphorus appropriates the ozone in great measure.

The results of the mutual action of phosphorus, air, and water are somewhat different, when, as in Schönbein's experiments, the air is allowed to stagnate over the phosphorus. In the phosphatic acid, as we may designate the solution which forms about the phosphorus in the ordinary ozone bottle, there are found "On the Sources of

So also Pugh failed to find NO, in similar experiments. Nitrogen to Vegetation." Phil. Tr., 1861, Pt. II, p. 496.

PO, and PO,, as has long been known; HO,, as Schönbein discovered,' and likewise NO,. As regards the last named substance, Meissner states that its quantity is but small, more of it being produced in one hour by his electrizing apparatus, than in 24 hours by phosphorus.

Schönbein has lately asserted the presence of nitrous acid and ammonia in the so-called phosphatic acid. The reactions on which Schönbein based the discovery of NO, are all, indeed, as he described them; but they all admit of a different explanation. The decomposition of KI by the phosphatic acid may be attributed to HO,; and a more direct reaction must be employed in order to demonstrate the existence of NO,. For this purpose Meissner freed the liquid of PO, and PO, by BaO, made it alkaline with KO, and, after suitably concentrating, examined it for NO, by means of FeO SO, and dilute SO,. In a few instances he found minute traces of NO, by this method; but in no case was NO, present in the quantity that would be indicated by the KI and starch test. As regards NH,, Meissner declares his inability to discover in the phosphatic acid more than the traces, which, as Faraday, Boussingault and others have taught us, are universally distributed on the surfaces of porous bodies and throughout the atmosphere.

Schönbein appears to place most reliance upon his experiments wherein a clean moistened sponge was used to absorb the vapors or cloud that is formed over phosphorus. He was perfectly right in asserting that the water obtained by squeezing the sponge after prolonged exposure, is neutral to test papers, but, nevertheless, strikes a deep blue color with acidulated solution of KI mixed with starch. Meissner assures us that this reaction is entirely attributable to a product of the action of ozone upon an ingredient of the organic matter of the sponge, viz: iodine; and that, on concentrating the water pressed from the sponge and adding to it sulphurous acid, a copious separation of iodine occurs. This reaction demonstrates that iodic acid, which decomposes KI with ease, gave the reactions from which Schönbein deduced the formation of NO, in the slow combustion of phosphorus.

In the examination of the so-called phosphatic acid, Meissner found evidences of the presence in it of another substance, possessed of reducing properties, opposed to the oxydizing quality of antozone. As previously observed, solution of pure KI, free from IO,, when acidified, after some time suffers decomposition with separation of I, and the rapidity as well as the extent of

And in very large quantity, compared with what is produced when the air is made to traverse water placed in another vessel. In the latter case, antozone which with water forms HO2, is too far advanced in its reversion to the inactive state to produce its highest effect.

the decomposition are the greater the larger the quantity and the stronger the quality of the acid added. If, now, two equal portions of the same solution of KI, each acidified with a drop of the same dilute SO,, are mixed, one with pure water and the other with the same volume of what remains of the phosphatic acid solution after it has been precipitated by CaO, it is seen that the separation of iodine is greatly hindered or entirely prevented in the latter case.

Further study of this liquid conducted to the result that it owes this reducing quality to ozone. In fact, when air ozonized by phosphorus or by electricity is allowed to stand at rest in a flask until all antozone has vanished, and then the flask washed repeatedly to remove all phosphatic acid or deposited matters, the ozone that remains communicates this property to pure water. Ozone water, as the liquid may be called, gradually loses its reducing quality when exposed to air or evaporated on the waterbath. Its properties are the opposite of those of HO,, which we may term antozone water. Ozone water and HO, may exist together in the same liquid, and, under certain circumstances, the former prevents the oxydations which the latter, if alone, would accomplish. This reducing power of ozone water is only relative, and not an absolute and invariably exhibited quality. Meissner has found indeed no means of directly effecting oxydations by means of ozone water; but he has learned that in some cases it does not limit or counteract oxydizing influences. Solution of KI, as is known, is decomposed by PbO, with liberation of I. The oxygen of PbO, acts accordingly like ozone. oxydation, so far from being hindered, appears to be promoted by ozone water. Meissner's observations on this so-called ozone water are, however, confessedly incomplete.'

This

He recalls, however, a fact noticed twenty years ago by Schönbein, who found that water which had been agitated for a long time with a large volume of air ozonized by electricity, was electro-negative compared with pure water. Schönbein remarks that ozone is taken up by water to only a very slight extent, and its voltaic activity is extremely small. Antozone-water, i. e. HO, is electro-positive compared to water. Meissner has experimentally confirmed these observations.

The action of phosphorus, according to the author's view, consists "in polarizing the inactive oxygen. It operates like an electrically excited body, and since it combines with ozone, which is negative-active oxygen, it operates like a positively electrized body, or has the effect of electro positive tension. Phosphorus must produce this polarizing effect by virtue of what we designate its great chemical affinity."—p. 256.

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May not the reducing action which HO, as ordinarily prepared, is well known to exert upon many oxyds, be due to the same cause as was operative in Meissner's experiments!

S. W. J.