OZONATION OF PURIFIED AIR BY M o m PHOSPHORUS.
5
THE INVARIABLE PRODUCTION, NOT ONLY OF OZONEAND HYDROGEN PEROXIDE, BUT ALSO OF AMMONIUM NITRATE, IN THE OZONATION OF PURIFIED AIRBY MOISTPHOSPHORUS.
111.-UPON
BY DR. A. R. LEEDS. As the result of very numerous quantitative experiments performed two years ago, and published in the JOURNAL AMERICAN CHEMICAL SOCIETY, I , 145, and Chemical News for August, 1879 (“ Upon ammoniurn nitrite, and upon the by-products obtained in the ozonation of air by moist phosphorus”), I gave the proofs of the statement contained in the heading of this article, and the determination of the amounts of the three substances formed. Forthwith, under the title “ Is ozone produced during the atmospheric oxidation of phosphorus?” (Chemical News, 40, 96) Mr. Kingzett, without waiting to disprove any of the above propositions by experiment, asserted that ‘. There is n o known process o f slow oxidation which h a s been established to procluce ozone,’’ and t h a t the gaseous body which I had obtained and experimented upon, was altogether peroxide of hydrogen. Mr. Kingzett insisted that the long series of washbottles and purifiers, which I had used to absorb and hold back as far as possible the hydrogen peroxide, did not militate a t all against his assumption, for the reason that peroxide of hydrogen suspended in a vesicular condition, might pass through all the washing liquids and constitute the only active agent in the escaping gas. H o w greatly Mr. Kingzett’s views have altered may be seen from the fact ( “ R e port upon the atmospheric oxidation o€ phosphorus, etc.,” Journal Cheniical Society, December, 1880) that the points most dwelled upon by him in this last paper are, that the escaping gas contains no peroxide of hydrogen whatsoever, but comists entirely of ozone, and that “ t h e peroxide of hydrogen formed in the process is entirely deposited in the water contained in the oxidisers ; and if it cannot escape condensation in the aqueous spray and vapor of the oxidisers, it cannot be expected to escape solution in five wash-bottles.” Since the statements of Mr. Kingzett now, are diametrically opposed to those which he made when he attacked my results in the beginning, I think it will facilitate the labors of future workerR in this field, if I present a brief summary of tho facts hitherto established. W h e n I first entered upon the study of the phenomena exhibited in the aerial oxidation of moist phosphorus (October, 1878), the first difficulty encountered arose from the unsatisfactory character of the
6
OZONATION OF PURIFIED
A I R BY M o I w PHOSPHORY’P.
apparatus previously employed, and the impossibility of obtaining a stream of oxidised air containing a uniform arid definite percentage of ozone. These difficulties disappeared when it was ascertained t h a t tlie volume of ozone produced, under given conditions, was a definite function of t h e temperature, and might accordingly be expressed by a curve, having its origin a t f j o C’., at which temperature tlie production was nul, and arriving a t ita maximum a t 21”, from this point falling off again rapidly. T h e manipulation was rendered easy by the phosphorus ozonator, described along with the volurnetemperature experiments (JOURNAL AMERICAK V H m f i c A L SOCIETY, I, 8, and ClkenL. ,Vews, 40, 1 5 7 ) . These results were referred to by Mr. Kingzett in the Chemical JcTezos for August, 1 H i 9 , and yet in his earlier experiments performed long subsequently (February, I R80), he states t h a t he obtained no satisfactory evidence of the production of ozone, and but little evidence of the production of peroxide of hydrogen. Later on, when working in summer weather, Mr. Kingzett obtained better results,.and discovered that his previous failures liad been due t o his having conducted the experiments a t too low temperatures. I n plotting t h e volume-temperature curve, tlie water in the jars of the ozonator was replaced by a solution of potassium bichromate and sulphuric acid of such strength, that t h e surface of the phosphorus was kept clean without undergoing the danger of ignition froin too concentrated acid and too rapid oxidation. Mr. Kingzett states that “such a method of experiment obviously precluded examination for peroxide of hydrogen in this solution, in which tlie phnsphorus was partially submerged,” and explained why he found t h e relation of peroxide of hydrogen t o ozone a t 1 : 400. T h e comment of Mr. Iiingzett would have been only too just if I had looked, o r proposed t o look, in a n acidified potassium bichromate bath f o r uridecomposed hydrogen peroxide. B u t Mr. Kingzett, who oriticised both papers a t length (Zoc. c i t . ) , must have known a t t h a t time, a year and a half ago, thougli apparently he has since forgotten, t h a t I did not employ such a method. The potassium biehro mate bath was employed in the determinatlon of the volume-temperature curve of t h e evolved ozone only, and in that investigation no attempt waR made to determine t h e hydrogen peroxide formed. T h a t question was taken up a t great length in t h e subsequent paper upon “Ammonium nitrite, and t h e by-products obtaineci in t h e ozonation of air b y moist phosphorus.” I n t h e experiments therein detailed, and in which the determination of t h e hydrogen peroxide in the ozonising chambers and in the variow wash-waters is express-
OZONATION OF PURIFIED AIR BY M o I w PHOSPHORUS.
b
1
l y considered, not merely water, b u t water especially purified f o r t h e purpose, was employed. This and many other precautions were essential at t h a t time, when t h e exact nature and excent of t h e sources of error were unknown. A n d since these sources of error are not even alluded to, nor suitable precautions t o obviate them taken b y Mr. Kingzett in his paper, i t will be necessary t o emphasize them here. A t t h a t time, and even now, t h e generation of ammoninm nitrite by evaporation of water was, and is taught, as an established fact. I f this were indeed t h e case, t h e ozonising chambers present the most favorable conditions f o r its generation, and t h e nitrite thus formed would give the same reaction as hydrogen peroxide or ozone, when we came to titrate the water in tho ozoriisers with an acidified solntion of potassium iodide. T h e elaborate experiments of Bohlig, Zabelin and Carius, however, have shown t h a t this is not true, and that t h e alleged formation of ammonium nitrite by evaporation of water in air, never takes place when adequate precautions are taken t o exclude from t h e evaporated water, the ammoniacal compounds pre-existent in t h e atmosphere. Fortunately, therefore, this source of error was not inherent in the experiments themselves, and i t only remained t o guard against it by very complete washing of t h e air drawn through t h e ozonator, Again, Goppelsriider and Carius had shown that when ammonia is brought into contact with ozone, it is decomposed with the formation of ammonium nitrite and nitrate, and peroxide of hydrogen. It was essential, therefore, t h a t the phosphorus should be in contact with water from which every trace of ammonia had been expelled, I f this were not done, t h e origin of a n y ammonium compounds or hydrogen peroxide, found among t h e products of t h e reaction, would be rendered doubtful. It was for this reason that all the water employed ill my experiments, in which a determination of the hydrogen peroxide was attempted, was aqua purissima, that is, water redistilled until it did not give the slightest reaction f o r ammonia when treated with Nessler’s reagent. Moreover, while t h e oxidation of water t o hydrogen peroxide b y free ozone had been abundantly disproved, yet there appeared to be much reason for supposing that during t h e aerial oxidation of moist phosphorus, a formation of hydrogen peroxide actually took place. If this were true, its origin could not be ascribed t o a secondary action due to the ozone first formed, b u t t o the same series of changes as those which led u p t o t h e oxidation of t h e oxygen mole-
s
OZ(JNAT1ON O F PCKIFIED AIR B Y MOIST PIIOSPIIORKTS.
cule itself. T h e only sufficient assignable cause was the formation of nascent oxygen, or oxygen in the atomic condition, such as it must necessarily cnter into during some mornelit of t h e chemical change, when a substance of uneven quailtivalence, like phosphorus, undergoes oxidation. T h a t oxygen in an uncombined or monatomic condition, might peroxidise the water molecule, nliile oxygen already combined in a triatomic molecnle might not, appeared to be a legitimate hypothesis. T h a t nascent oxygen might oxidise the nitrogen molecule a t the same time, arid generate, in the pwseiice of water, ammonium nitrate, I regarded likewise as a not improbable supposition. F o r this reason, excessive care was taken t o preclude the presence of atmospheric ammoniacal or nitrous (*ompounds,both in t h e air drawn through the ozonator, and also in the water brought into contact with t h e phosphorus in t h e ozonator jars. T h e mental picture which wab formed a t t h a t time of t h e sequence of phenomena to be studied, was embodied in t h e following equations, the last three being imagined as contemporaneous: (1.) P, o,, = 1’206 P,O, 2 0 , 0 0. (2.) 0, 0 = 0,. ( 3 . ) HOH O = Ii00H. (4.) Nh’ 2H20 0 = NH,NO,. T h e experiments performed now two years ago, and t h e repetition of which, though in an imperfect manner and with t h e neglect of essential precautions, constitute t h e substance of Mr. Kingeett’s report to the Chemical Society above alluded to, were framed with a view of testing t h e t r u t h or falsity of the above propositions. W h a t these experiments actually were, may be seen b y inspection of t h e accompanying scheme of them, which, with one exception, was followed t o t h e lettey . I. Use of a measured amount of aqua purissima in t h e ozonator jars. 11. Complete straining and washing ot t h e air by means of cotton wool, aqua purissima, caustic soda and sulphuric acid, bQth of the latter previously tested and shown to be free from nitrogen compounds. 111. Height of t h e phosphorus cakes before and after t h e experiments. IV. Amount of ammonia in the jar-water a t t h e close of the experiment. V. Amount of t h e nitrites and nitrates, as determined by reduction.
+
+ + +
+
+
+
+ +
OZONATION OF PURIFIED AIR BY MOIST PROSPHORUS.
9
VI. Amount of nitrous acid, as determined by metadiamidobenzole. VII. Amounts of phosphoric and phosphorous acids, and of hydrogen peromide in the jar-water (ozonising chambers). V I I I . Estimation of ammonia, nitrates and nitrites, nitrous acid alone, phosphoric acid, phosphorous acid and hydrogen peroxide, in the water used to wash the escaping product3 of ozonation.
IX. Similar estimations, except of t h e phosphorus compounds, in the solutions used to wash the entering air.
X. Measurement of total volumes of air used, and of ozone after its escape from the water employed in washing. With regard to the first two heads of this scheme, it is to be noted t h a t the proof of the exclusion of all compounds of nitrogen from the substance entering into the reaction, was essential to establishing this vital fact-that any nitrogen compounds found among the products were the results of chemical changes induced in the process of ozonation itself. T h a t this preliminary proof was of the highest importance was shown by the results of the investigation; it was found that while 110 ammonium nitrite was present in the water of the ozonising chambers or in the wash-water, of ammonium nitrate a considerable amount (27.39 mgrrns) was present in the first, and a determinable quantity (0.81 mgrm) even in the latter. Until adequate experimental evidence, therefore, is adduced to the contrary, the formation of ammonium nitrate during the ozonation of purified air b y moist phosphorus, is t o be regarded as a fact which cannot be overlooked, and one which demands an explanation in any theoretic account of the chemical phenomena involved. Mr. Kingzett, however, does not even contemplate the possibility of the nitrogen, which is relatively the most abundant of the substances present, taking part in the reaction. To say nothing of the fact that his arrangements for washing the air were inadequate, there is no proof given t h a t the water used by him in contact with the phosphorus was pure. If it wzs ordinary distilled water, it certainly was not pure, but contained the very body (ammonia) which was the worst possible impurity, so far as the question a t issue was concerned. Not to speak of the discovery of Goppelsrijder and Carius, t h a t ammonia is converted by ozone into hydrogen peltoxide and the nitrate and nitrite of ammonia. N o experiment is narrated b y Mr. Icingzett in which he sought to determine whether nitrous acid was present or not, in any of the liquids examined. I n the entire absence
10
OZONATIOX O F P U R I F I E D AIR BT MOIST PIIOYFHORLb.
of such tests, his determinations of t h e amounts of hydrogen peroxide, etc., are correspondingly incomplete. T h a t this is not hypocriticisni, is sliown by the fact that the dense white fumes which are seen in the ozonising chambers, a t one time were attributed by Scliunbein to ammonium nitrite. 1Sy referring to the sevetith liead of t h e scheme, it will be seen that the determination of hydrogen peroxide in the ozonising chambers was expressly mentioned, and ns preliminary to this determination, experiments were made upon the possible influence of phosphorous acid upon the titration for the peroxide, and elaborate pains were taken t o prove the absence of nitrous acid in tlie water esamined. My surprise was very great on finding, after the publication of the paper, that while the hydrogen peroxide in tlie wash-water, and every other point in t h e scheme had been determined, this particiilar estimation had been overlooked. F o r this reason, in every communication written subsequently, I have never wnimitted myself to any statement as to the total amount of hydrogen peroxide produced, knowing that it was t h e sun1 of three quantities: 1st. T h a t referred t o under t h e seventh head, which remains behind in the jar-water. 2d. T h a t carried forward in a state of aerial suspension, and partly detained by the mash-water. 3d. That escaping along with tlie ozone in t h e evolved gas. A h . Kingzett has called niy attention t o t h e oversight in carrying out this important part of t h e general scheme, and has made some estimations of tlie amounts of hydrogen peroxide i n tlie ozonising chanibers. Unfortunately, from his use of an acidified solution of potassium iodide as a reagent for titrating t h e evolved gas, and from his having employed a fan to blow the air through the apparatus without indicating t h e method of measuring the air, I am unable to use his results. I n my own experiment, in which 56 liters of purified air were drawn through t h e ozonator, t h e jars containing pure water, t h e amount of ozone in the evolved gas was 44.47 mgrnis; that of hydrogen peroxide in the jar-water, 35.69 mgrms. This would give f o r ' t h e ratio of the ozone to t h e hydrogen peroxide, in this particular experiment, 1 : 0.8, or by molecules (0, = H,O,), as 1 : 0.8. 111 niy earlier paper (August, 18791, the amount of ozone in the evolved gas bore t o the amount of peroxide of hydrogen, t h e ratio of 400 : 1. In these experiments, i t was supposed that a long series of wash-bottles was sufficient t o wash out t h e aerially suspended hydro-
OZONATION OF PURIFIED AIR BY MOIST PHOSPHORUS.
11
gen peroxide, and hence t h e number, 400 : 1, was taken as expressing t h e relation between the total quantities in t h e gas, after its escape from t h e ozonising chambers. No statement was made, either then o r subsequently, as to the total amount of hydrogen produced (owing to my original oversight in failing to determine i t in t h e water of t h e ozonising chambers), b u t only t o t h e amount in t h e evolved gas. Subsequently, after much more elaborate experiments ( Chern. 1\Tews, 42, 19), this assumption was found to be false, and t h a t after passing not only through t h e wash-bottles, but a length of sulphuric acid dryers, so great t h a t every trace of moisture was removed, the ratio of the ozone t o the hydric peroxide in the evolved gas, was f a r less than 400 : 1. I n the last and best agreeing series of trials, i t was as 51: 31, or 1 : 0.67. T h e ratio of the ozone to the water formed b y t h e decomposition of the hydrogen peroxide with the aid of heat (at 200’) was 5 1 : 16, or approximately 3 : 1. Tliis ratio was accidentally given instead of t h c former, in stating t h e result of t h e trials (ZOC.
cit.)
B u t it will b e asked, what proof is there that t h e neutral solution employed in titrating the current of ozone and hydrogen peroxide, would indicate t h e ozone only and not t h e peroxide as well? T h e answer is t o be found in the fact t h a t hydrogen peroxide held in vesicular suspension will pass through neutral potassium iodide s o h tion without causing any appreciable decomposition in t h e latter. This was verified in t h e following experiment.* “Perfectly pure and d r y oxygen was ozonised b y one of t h e ‘ ozonising elements’ (electrical ozonisers), and then drawn through three bulbs, the first containing a solution of neutral potassium iodide, t h e second water, and t h e third chromic acid. T h e latter was connected with an aspirator. As soon as the strongly oxonised oxygen came into contact with t h e potassium iodide, a very slow current being employed, a yellow coloration made its appearance on t h e Rurface of t h e solution in t h e first bulb, and above t h e snrface t h e characteristic white cloud. On increasing t h e rapidity of the current, this white cloud was drawn through t h e water and chromic acid into t h e aspirator, and remained f o r one o r more hours before its absorption was complete. After drawing over six liters of oxygen containing 0.194 g r m of ozone, the water was titrated, and found t o have absorbed 0.31 mgrm of peroxide of hydrogen. T h e chromic acid solution was unaffected, Ahowing t h a t the suspended hydrogen peroxide may pas8 *JOURNAL AMERICAN CHEMICALSOCIETY, 2,157.
through i t without effecting a dccomposition. T h e same remark applies to a neutral potassium iodide solation put in the place of the chromic acid. T h e excessively dilute hydrogen peroxide held in a state of aerial suspension, was not able to decompose the neutral iodide during the coursc of the experiment. Of course, an cccitl@etl solution could riot be employed t o a h o r b the peroxide, since, as above showii, its tleeompositio~i occurs iinder the act,ion of oxygen alone.” The conclusion, therefore, to be drawn from t h e above result is, that’ in t h e ozonation of air by moist phosphorus, the number of molccules of hj-drogen peroxide approximates very nearly L O an equality with the number which is, pari passu, formed of molecules of ozone. T h a t it does not fully equal t h e number, may possibly bc connected with the production, as t h e third essential result of t h e action of nascent oxygen under the circumstances studied, of a certain amount of arninoniuin nitrate. And not only does this relation exist, between but subsists t h e amounts of ozone and hydrogen peroxide pi*o(Zi(*:e~Z, with little alteration, after t h e two bodies have been p:issed tlirongh many nash-bottl(?s and have been, for a considerable interval, in contact with one another in the evolved yns. Xow t h a t I have i*eviened my own labors in this direction, I wish briefly t o examine N r . Kingzett’s statements concerning them. A f t e r incorrectly stating that I looked for hydrogen peroxide in an acidified potassium bichromate bath, S h . Kingzett adds : ‘‘ Moreover, it is not apparent from his various communications that lie subjected his gaseous producat to aup very specid cbxamiriation. EIe seems to have relied upon its odor and general characters rather than upon any exclusive properties, as evidence of its nature.” I n the first place, with regard to the odor, Mr. IGngzett has apparently overlooked the fact that, unlike his present position, which is t h a t t h e body evolved is all ozone, atid contains 110 hydrogen pcroxide, he maintained a t t h a t time t h e opl~osite-that the g a s evolved was altogether. hydrogen peroxide, and contained no ozone. A n d the only coririection in which I have brought forward t h e sinell of ozone, as an important physical quality, was t o state that attention t o i t might have prevented Mr, Kingzett from so positively affirming that a gas which possessed the powerful and unique smell of ozone, was not ozone, but another body, viz: hydrogen peroxide, which is entirely odorlcus. In the next place, Mr. Kingzett has hrought forward only two tests, which differ f r o m those which I have applied. T h e first con-
OZONATION OF PURIFIED AIR BY MOIST. PHO8PHORUS.
13
sisted in passing the ozonised air through turpentine, and assuming that the failure of the gas, after its passage, t o set free iodine in a potassium iodide solution, demonstrated that it originally contained ozone only. But until it has been shown that hydrogen peroxide suspended in the gaseous current, would not undergo absorption by oil of turpentine as well, the proof is valueless. T h a t this absorption would probably take place m a y be inferred from t h e action of organic liquids in general, for when the cnrrent of ozonised gas is passed into alcohol, ether or glycerine (JOURNAL AMEMCAN CHEMICAL SOCIETY, I, 446), the white cloud entirely disappears, and hydrogen peroxide is found i n the liquid. I n this respect the organic liquids strikingly differ from solutions of potassium iodide, water, acidified chromates, etc., inasmuch as the latter do not arrest the suspended hydrogen peroxide. Mr. Kingzett's second novel test consisted in heating the ozonised air t o 240°, and assuming that the entire destruction of the active agent a t this temperature proved that it was ozone. The information t o be derived from beating the gas under proper conditions, is perhaps the most conclusive of any t h a t can be obtained, as t o its true nature. Rut, as Mr. Kingzett has applied the test, he has deprived it of the very conditions essential t o ita value. F o r a t 240°, not only ozone, but also peroxide of hydrogen is destroyed, and there is nothing in the test as he has applied it, t o prove t h a t the active agent was ozone only, or peroxide of hydrogen only, or a mixture of both. Prior to this, I had made use of the same test (JOURNAL ANERICAN CHEMICAL SOCIETY, 2, 147, and Chem.News, 42, 19), but in a different manner. T h e ozonised air, after extended washing, was eompletely desskated, and then exposed to temperatures running from the ordinary up t o 200'. It was shown that as the reaction for ozone, diminished with the successive increments of temperature, the quantities of water derived from t h e decomposition of the suspended hydrogen peroxide, as regularly increased. T h e numbers obtained by experiment exhibited this diminution of ozone and increment of water, as uniformly as was to be reasonably anticipated in view of the difficult nature of the work. T h e total amount of water obtained in twelve experiments was 0.0086 grm, corresponding t o 0.016 g r m hydrogen peroxide ; the total amount of water obtained in blank experiments continued for a much longer time than those reported, and differing from the latter only in the circumstance that the phosphorus cakes were kept submerged beneath the surface of t h e water in the ozona-
t o r jars, was zero. W e h a r e seen with what neglect of essential precautions JIr. IGngeett has applied this test. Against my results he has to urge merely his conviction (U) that they \rere wrong, and t h a t the amounts o f water weighed were dne t o water only, and not to H,O,. It is l i a i ~ l l y\vvcirtli wliile t,o uominent-0.01ti g r m is a ponderable quantity, the reality of nhicli is c;tpalile of experimcntal proof or disproof, whilst a convict~iori is not necessarily of any weight except in the mind of its aiithoi'. T h e only experimcnt which hlr. Iiirigzett has brought forward in this connection, shows that he has failed t o apprehend t h e real (luestion at issue. H e passed a rapid currvnt of air throngh a solution of hydric peroxide, and inferred that the failure of the air, after its passage, t o effect a noteworthy decorripsition in ail :tciclified potassium iodide solution, proved (what it did not) that no IT@, c:oulrl be curried forward wlien the H202was i i i a stcite of c t e ~ i c ds u q ~ e i t s i o i i . Jlr. Kingzett's experiment is ;t repetition of a similar one of my own published previoiisly (JOURYAL A J I E I H ~C~IAI E SMI~A SOCIETY, I, 2, l 5 4 ) , hut illustrates merely the well-knowri fact that hydrogen peroxide is R difficultly vaporisable body. 1\11.. Kingzet,t appears t o think t h a t the use of a rapid stream of air had some bearing u p o n the question, and speaks of a spray of peroxide of hydrogen. T h e plienoniena which are under inveqtigation cannot be studied in this rnatint:i'. The state of vesicular suspension of t h e hydrogen peroxide is riot one wliich, so f a r as we are a t present aware, ('an he brought about t)y incachanical means, but is one which liyilrogeii peroxide assumes only when it is the immediate result of a previous cliemical change. This is its condition when formed in the pliosphorns ozonator, and likewise when ozone uiidergoes decomposition in presence of water, as when it is absorbed by a solution of potassium iodide, and is the origin of the white cloud seen under these circumstances over tlie surface of t h e latter. T h e differelice between the two conceptions Mr. Kingzett would have noted, had he been acqimiiited with what is the most striking reaction which occurs during t h e ozoiiation of air by moist phosphorus. This is the permanelit white cloud which fills the ozonator, and is carried forward tlrrougli ari extensive series of wash-bottles, and remains sometirnes f o r hours without undergoing absorption, above t h e surface of the water in itn aspirator employed to draw air through the apparatus. This white cloud was the antozone of Schunbein, which he, and a f t e r him, hleissner, labored unsuccessfully for so many years t o account for. F o r our knowledge o f its true nature we are indebted mainly to Von Babo, and after liim to Nasse
OZONATTION OF PURIFIED
AIR BY MOIST PHOSPHORUS.
15
and Engler, who demonstrated that the so-called antozone iR merely hydrogen peroxide, in a state of vesicular suspension. T h e stumbling-block which rendered of so little value the life-long labors of Meissner upon thie question was, that starting out from the well-established fact tnat hydrogen peroxide is not volatile, he concluded that the clouds could not be due to this substance. As t h e only alternative, he and Schonbein ascribed them to a peculiar modification of oxygen, other than ozone. There is danger of our giving up ground acquired with great difficulty, and falling back into hopeless contradictions, if we do not keep clearly in mind the distinction between hydrogen peroxide in its ordinary condition, in which it is not volatile, and hydrogen peroxide as suspended a t the moment of its formation, in a current of air or aqueous vapor. An atmosphere saturated with aqueous vapor is most favorable to the existence of the hydrogen peroxide in a state of vesicular suspension, but is not essential, since after complete withdrawal of the water vapor, the RUEpended hydrogen peroxide will still be present. SUMMARY.
1st. Both ozone and hydrogen peroxide are produced during the ozonation of purified air b y moist phosphorus, in the ratio approximately of one molecule of the latter t o one of the former. 2d. Both bodies are evolved, the suspended hydrogen peroxide passing through a series of wash-bottles, without undergoing any but a alight absorption, and being present in the evolved gas in nearly the same ratio as that which it held t o the ozone, when. originally produced. 3d. Along with these two bodies, and as a necessary part of the same series of reactions, incident originally to the setting free of nascent oxygen, a certain amount of nitrate of ammonia is invariably produced. This last is altogether detained in the water of the ozonator and of the wash-bottles.
