Hence it appears that in the former case the action of the dissolved oxygen is determined by the action of the permanganate*.

In order to investigate quantitatively the relation of these two actions, several series of determinations were made in the following manner :-A measured quantity of a solution of protochloride of tin of convenient strength was determined, first without dilution, and then, in successive experiments, after dilution with regularly increasing quantities of water. Immediately before and during each determination, a stream of carbonic acid was poured into the flask containing the liquid to be determined, in order to guard it from contact of air. The conclusions to which these experiments have led are as follows:-(1) When the diluting water contains only so much oxygen as is sufficient to oxidize about one-third of the protochloride of tin present, the whole of this oxygen is appropriated in the reaction; (2) after this point, the amount of induced oxidation is still increased by further dilution, but in a continually diminishing degree, until it bears to the primary oxidation (that by the permanganate) about the ratio of 2:3; (3) still greater dilution produces no further change. It has not yet been found possible to determine the exact ratios of the primary and of the induced oxidation one to another at that point at which the absorption of dissolved oxygen ceases to be complete, and at the final limit, where the induced oxidation has reached a maximum.

With what other chemical actions are we acquainted which belong to the same class as this action ?

Four examples may be adduced of actions more or less analogous. 1. The action of platinum-black, and other similar substances, in causing oxidation. These substances, however, do not, so far as we know, themselves undergo any change; whereas the permanganate can act inductively only during the moment of its own direct action. 2. The action of nitric oxide upon sulphurous anhydride and oxygen. 3. The action of pentachloride of antimony in presence of free chlorine in causing the formation of chlorine compounds. But in these two cases also an important distinction is to be noted. The products of the initial action, nitrous oxide and terchloride of antimony, are capable of combining directly with free oxygen and free chlorine respectively; whereas the final product at least of the reduction of an acid solution of permanganate is not liable to reoxidation, and such a solution can accordingly be reduced by many substances in the presence of dissolved oxygen without appropriating or conveying it. 4. The acetous fermentation. The fact that the oxidation of alcohol by free oxygen may be induced by the presence of other substances undergoing chemical change bears some resemblance to the fact here brought forward. It is not improbable that the two may depend upon a

common cause.

But no case that has been yet examined is directly and unmistakeably parallel to this action. At the same time, it is doubtless but one of a class. The action of other similar oxidizing bodies, such as chromic acid, and of other substances readily susceptible of oxidation, such as sulphurous acid, hydriodic acid, &c., in presence of dissolved oxygen, may probably present similar phenomena. With the action, in dilute solutions, of chromic acid on sulphurous acid, and permanganic acid on sulphurous acid, this has been ascertained to be the case.

On Schönbein's Antozone.

By G. HARLEY, M.D., Professor in University College, London.

In 1842 Schafhaütl called attention to a fluor-spar, the peculiar smell of which he imagined to be due to the presence of hypochlorite of lime. Schönbein shortly afterwards found that it contained an oxidizing agent which Schrötter subsequently described as ozone. Schönbein has now repeated his experiments on a better quality of the mineral, and finds that the oxygen contained in it resembles that yielded by Ba02; and that distilled water in which the mineral has been pounded

Since reading the paper of which the above is an abstract, the author has become aware that this fact had already engaged the attention of the German chemist Löwenthal, who, in conjunction with E. Lennsen, has recently shown that dissolved oxygen is similarly rendered active in some other cases (Journ. für Prakt. Chem. 1859, part i. p. 484, and vol. lxi. (1862) p. 193).

acquires peculiar properties. At the request of Professor Liebig, who had given Dr. Harley some fine specimens of the mineral, the latter gentleman showed some of the more striking properties of the mineral to the members of the Association. For example, the distilled water in which the mineral has been pulverized, when filtered gives no precipitate with nitrate of silver, and only the very slightest turbidity with oxalate of ammonia and with weak sulphuric acid. From this it is seen that no chlorine is present, and only a trace of an earthy base. The liquid blues iodized starch, decolorizes a solution of permanganate of potash acidified with sulphuric acid, at the same time liberating oxygen gas. The liquid gives a blue with the brownish mixture of dilute ferridcyanide and perchloride of iron, and gradually precipitates prussian blue. When mixed a short time with the peroxide of lead and finely reduced platinum-powder, it loses some of the above-named properties. Heating the mineral entirely destroys its properties. Schönbein concludes from these and other facts that the mineral contains antozone.

On the Adulteration of Linseed Cake with Nut-cake.
By W. H. HARRIS, F.C.S.

The frequent adulteration of linseed cake, used for cattle-feeding purposes, has drawn considerable attention on the part of the agricultural chemist to the different adulterative substances employed by the trade. Many of these have been from time to time exposed. But there is one substance largely used for adulterating linseed cake, which has not, that I am aware of, received the notice which it deserves. The substance I refer to is the market nut-cake, obtained from the fruit of the Arachis hypogea, or Ground-nut of America, indigenous to Mexico, but cultivated in the West Indies. As botanists are aware, it derives its name from the singular manner in which its fruit is perfected; for as its yellow papilionaceous flowers fall from their stalks, the pods which follow are forced by a natural motion of the plant into the ground, where the seeds ripen and come to perfection-hence the name of Ground-nut.

As the cake composed of the marc of these seeds can be purchased at about half the price of linseed cake, it is often used for the purpose of adulteration—a fact patent to most agricultural chemists. But this substance seems to have been generally condemned as a worthless article; for we have seen this verdict given against it in several instances by eminent agricultural chemists; at any rate, if I am mistaken in the article of commerce which has been classed with bran, rice dust, and treated as rubbish, the mistake is attributable to an unfortunate looseness of language adopted by the authorities in question.

My attention being directed to the true feeding qualities of this substance was accidental; for having to analyse a sample of linseed cake which contained a considerable quantity of bran, I was surprised to find the analytical result, in reference to the percentage of flesh-formers, was considerably superior to the result I had obtained from many genuine samples I had analysed. This led me to resubmit the cake to a careful microscopic examination, which enabled me to detect what afterwards proved to be the decorticated nut-cake of commerce.

My next step was to get a sample of this nut-cake in its simplicity; this, through the kindness of a gentleman connected with the trade, I succeeded in doing. On submitting this sample to analysis, the result exceeded my highest expectations, as the following results of the examination will show:

Moisture.
Ash...

Cellulose, insoluble in warm solution of potash, sp. gr. 1045
Albuminous compounds*.

Amylaceous constituents.

Oil

Per cent.

8.50

4.94

3:51

43.31

27.34

12.40

100.00

To be able to introduce to the cattle-feeder a highly nutritious substance, capa

* Containing nitrogen 6·93 per cent.

ble of sustaining a successful competition with linseed cake itself, and not more than two-thirds the market value of the latter, it now only remained to prove that its practical answered to its theoretic value. Of this there did not appear to me to be any serious doubt; nevertheless I thought it better to put the matter to the test of practical experiment. A friend to whom I named the subject readily entered into the plan of trying the effect of this cake upon a portion of his stock; the result proved his cattle would eat it with eagerness, and, as far as the experiment has gone, it has answered our highest expectations.

On a Simple Method of taking Stereomicro-photographs. By CHARLES HEISCH, F.C.S., Lecturer on Chemistry at the Middlesex Hospital. After trying various plans, the author devised the following, which answered perfectly. A microscope with its eyepiece removed is placed in a horizontal position, and fitted to an ordinary sliding back, single lens, stereoscopic camera. Behind the object-glass is screwed an adapter, in the inside of which is a tube, which can be turned half round by means of a lever from the outside. Sliding in this tube is a second, furnished with a stop which cuts off half the pencil of light coming from the object-glass, in fact occupies the same place as the prism of a binocular microscope. The distance of this stop from each object-glass is adjusted experimentally by sliding the tube backwards and forwards till the best effect is obtained. The prepared plate being put in its place after carefully focusing the object, the first picture is taken. The plate is then shifted, the stop turned half round, and the second picture taken on the other half of the plate. If the object be of any thickness, its upper surface should be focused for one picture, and its under surface for the other.

The adapter with its stop was exhibited to the meeting.

Lowe's Ozone Box. By E. J. LowE, F.R.A.S. &c.

This box has been constructed so as to ensure perfect darkness to the test-paper without interfering with the passage of a current of air. There are two openings into this cylindrical box, the one above and the other below. These openings are not direct into the box itself, but into narrow winding passages in the first instance; they are also opposite each other. If the wind is blowing in an easterly current, and the upper opening is on the east side, then the air will enter the box on the Fig. 1. Fig. 2.

upper half (fig. 1), will move round the circular passage until it enters the central cavity (A) where the test-paper is hung, afterwards passing round the lower passage (fig. 2) in a contrary direction, and out again at the west aperture. Or if the wind happens to be in the opposite direction, it will enter from below and leave the box from above. The advantage is obvious-a current of air passes through a dark chamber. The box is small, and its price almost nominal.

Observations on Ozone. By E. J. LowE, F.R.A.S. &c.

The following are results of observations made at the Beeston Observatory during the past four years:

1st. If the temperature is raised, the amount of ozone will increase.

2nd. If the current of air through the box increases in rapidity, the amount of ozone will increase.

3rd. As the barometer becomes lower, the amount of ozone becomes greater. 1st. If the temperature be ranged in 10° series, a temperature between 30° and 40° will give less ozone than one between 40° and 50°, and this less than one between 50° and 60°. Artificially, if a night-light be made to burn in a cell below the box so as to warm it, there will be an increase in the amount of ozone over another box that is without a night-light. 2nd. With respect to an increase in ozone resulting from an increase in the speed of the air, it is shown from this series of observations that the most ozone has been present when there has been a gale blowing. It does not necessarily prove that under these circumstances there is actually more ozone in the air; for it must be borne in mind that if the amount of ozone in a cubic foot of air were always the same, still if today 300 cubic feet of air only occupies the same space of time in passing through the box as 100 cubic feet occupied yesterday, we shall have more ozone apparently shown today than yesterday. Then again, as chemical action increases with an increase of heat, it is also manifest that the same amount of ozone passing through the box at a temperature of 60° would necessarily darken the paper more than the same amount at a temperature of 40°.

It is quite clear that certain corrections are requisite in order to find the actual amount of ozone.

3rd. With regard to the pressure of the air, there is a striking difference between the readings of the ozonometer with a high or low barometer. Taking the four days in each month during the past year on which the mean pressure was greatest, the average amount of ozone was 1.2, whilst on taking the same number of days when the barometer was lowest, the mean was 4.1, or nearly four times as much; four years' observations give very similar results. The mean maximum pressure for the whole twelve months of the four years is 30-22 inches, the mean ozone being 10; the mean minimum pressure for the like period is 29·18 inches, the mean ozone being 3.2.

With the barometer at 28 inches the mean ozone is 5.7

There is a difference between the amount of ozone during the night and day at

different seasons.

In December and January an excess at night over the day of 0.8

In February and March

In April and May

In June and July

The average of the summer months being in excess only one-half of that which occurs in the winter.

On the Luminosity of Phosphorus. By Dr. MOFFAT.

If a piece of phosphorus be put under a bell-glass and observed from time to time, it will be found at times luminous, and at others non-luminous. When it is luminous, a stream of vapour rises from it, which sometimes terminates in an inverted cone of rings similar to those given off by phosphuretted hydrogen; and at others it forms a beautiful curve, with a descending limb equal in length to the ascending one. Results deduced from daily observations of the phosphorus in connexion with the readings of the barometer, the temperature and degree of humidity of the air, with directions of the wind, for a period of eighteen months, show that periods of luminosity or phosphorus and non-luminosity occur under opposite con

ditions of the atmosphere. By the catalytic action of phosphorus on atmospheric air, a gaseous body (superoxide of hydrogen) is formed, which is analogous to, if not the same as, atmospheric ozone, and it can be detected by the same tests. The author has found, by his usual tests, that phosphoric ozone is developed only when the phosphorus is luminous.

On Ferrous Acid. By W. ODLING, M.B., F.R.S.

The author found that when ferric oxide was ignited with the carbonates of potassium, sodium, and calcium, each atom of fe, O, drove out one of CO2, to form two atoms of an alkaline ferrite, having the general formula M fe, which salts were decomposed by water into caustic alkali and ferric monohydrate or brown hæmatite; thus, M fe O2+H2O=H fe →2+MHQ.

2

On the Synthesis of some Hydrocarbons. By W. ODLING, M.B., F.R.S. The author found, in particular, that when a mixture of carbonic oxide and marshgas was passed through a red-hot tube, acetylene was abundantly formed according to the equation CO+CH, CH2+H2O.

On the Nomenclature of Organic Compounds. By W. ODLING, M.B., F.R.S. Admitting the impossibility of establishing a thoroughly systematic nomenclature in organic chemistry, the author advocated a gradual improvement of that now in more or less general use, by removing its chief incongruities, and remedying its more striking inconveniences. He showed, by many examples, how great an improvement might be effected by an introduction of very few and trivial changes,

On the Essential Oils and Resins from the Indigenous Vegetation of Victoria. By J. W. OSBORNE.

The indigenous trees and shrubs of the colony of Victoria belong for the most part to the genera Eucalyptus and Melaleuca, which grow in great luxuriance over the greater part of the Australian continent. In no other localities are oil-bearing plants to be found in the same abundance, especially such as attain to arborescent growth, nor is the yield of oil as great elsewhere. The thirty-five samples submitted to the Section are identical with those exhibited in the Victorian Department of the International Exhibition. They were distilled by the Exhibitors, at the request and under the auspices of Dr. Ferdinand Müller, the Government Botanist of Victoria, to whose great talents and untiring energy the colony is largely indebted. In the present case the rigorous accuracy of the specific name of each specimen may be accepted on his authority.

The author, as Juror, examined the essential oils and resins with respect to their technological value, for the Victorian Commissioners.

Those from the genera Eucalyptus and Melaleuca (nineteen different oils) resemble the Cajuput of India, Melaleuca leucadendron. In smell and taste they are generally more camphoraceous, partaking sometimes of the odour of oil of lemon. Their colour is for the most part a pale yellow, sometimes colourless, and occasionally green. Their specific gravity, in the samples submitted to the Section, varies from 0.881 to 0.940, the average being about 0.910. These oils have all two boiling-points, the lower being, generally speaking, about 325°, and the other about 40° higher.

They burn well in suitable lamps, and are not dangerous, as they are ignited with difficulty. As solvents for resinous bodies, they surpass most liquids of the kind, and form varnishes, attacking with readiness the intractable Kauric gum of New Zealand. The yield from individuals of the series is sometimes exceedingly large, E. amygdalina giving by distillation of 100 lbs. of its green leaves and branchlets, three pints of oil; E. oleosa, 20 ounces; E. sideroxylon, 16 ounces; M. linarifolia, 28 ounces, &c. It is estimated that 12,000,000 acres of the colony of Victoria are covered with myrtaceous vegetation of this description, some of it of a shrubby character, densely covering vast tracts (E. oleosa, F. M.; E. dumosa, Cunn.; E