that if reduction of temperature be added to pressure, every gas known in nature can be liquefied, or even made solid. But this fact has aided us in coming to a true conclusion as to the ultimate constitution of gases. Bernouilli first enunciated the idea that gases are formed of inconceivably minute material particles, free in space and animated by very rapid rectilinear movements, and that the tension of elastic fluids results from the shock of their particles against the sides of the containing vessels. And this, which

is known as the kinetic theory of gases, has been recently developed by Clausius and Clerk Maxwell.

If, then, a gas occupying a certain volume, composed of a definite number of particles, be in a closed vessel like the cylinder of an airpump, the pressure which it will exert upon the piston will be determined by the number of shocks of the molecules diffused through the neighbouring stratum of gas. If, therefore, the volume of the gas be reduced, the number of particles in this layer will be increased, as well as the sum of the shocks; and in that proportion the pressure will be augmented. The velocity with which these ultimate molecules move is enormous. Clausius concludes that the molecules of air move with a mean velocity of four hundred and eighty-five metres a second, and those of hydrogen one thousand eight hundred and forty-four metres in the same time. But they cannot all move at the same rate; for they must constantly clash against each other and rebound. But by this freedom of movement they are very nearly emancipated from cohesion. In liquids, the power of cohesion is palpable, although it is such as to admit of the gliding of the molecules over each other. The molecular cohesion is constantly at strife with the force of expansion

which, if unopposed, would launch the molecules into space. Clearly, then, we must lower the 'kinetic energy' of a gas and increase its cohesion, until the moment arrives when the cohesive force asserts itself, and the liquid condition will be secured.

This explains why certain of the gases were for so long considered 'permanent.' It was from the enormous degree of pressure, combined with the extreme reduction of temperature, required to give the molecules of such gases power to exercise their cohesive influence on each other. And it was by devising means for jointly securing these conditions that MM. Cailletet and Pictet have liquefied the 'permanent' gases; and the latter has even solidified hydrogen; and as the solid particles fell upon the floor they gave out that metallic ring which, amongst other things, confirmed the far-seeing idea of Faraday, that Hydrogen is a metal. The result of this is, that from a physical point of view, gases and vapours have the same constitution: being formed of molecules which move freely in space.

Thus it is in the gaseous state that matter becomes more accessible to our knowledge; but full of wonderful fact and suggestion as all this is, it must be distinguished, by the mind loving accuracy and truth, from actual demonstration. It is an hypothesis after all, however beautifully in harmony with the experiments it seeks to explain. It assumes that gases-indeed, that all matter, consists of molecules, which in turn are bundles of atoms. But no one has ever seen molecule or atom, and we may fairly predict that no one ever will. Yet the probability that this explanation of the nature of gases is a correct one is very high; and the phenomena of the Radiometer only lend additional weight to the inference; and it is not without wonder that one contemplates the

mathematical side of this great problem, and finds that the human mind has sought to determine, not only the velocities of the gaseous molecules, and the prodigious number of their collisions during a unit of time, but also their distances from each other, their absolute number in a given volume, and their dimensions.

The industry of the Bee is proverbial, but not certainly more than it deserves to be. The visits of insects to

flowers generally are mutually helpful to flower and insect. They give honey to the insect and cross-fertilization to the flower. The effort of nature to avoid self-fertilization is, as even proved by its exceptions, very manifest. The pollen is the fertilizing agent. In the majority of cases this is borne in the same flower as the seed which needs fertilization in order to be fruitful. But very special arrangements are made between the flower and the visiting insect to ensure that, as it secures for itself the nectar which the flower contains, it shall bring to the surface to be fertilized the pollen of another flower, and take away the pollen of the one it is then visiting to give fertility to yet another. This is, of course, not confined to bees. For example, there is a hedge-flower, common in the South, known as the Birthwort. The flowers are not conspicuous, but are tubular, with the wider end of the tube at the top. At the lower and smaller end of the tube the flower expands into a hollow sphere. In this there is nectar. Small insects creep into the tube in search of the nectar; their way is 30mewhat impeded by the presence all along the tube of needle-like hairs, all pointing downwards, and only on this account admitting of the entrance of the fly. Having once entered the hollow sphere, the insect finds plenty of nectar. But the pollen-bearing parts -the anthers are not at this time ripe; they have not opened and emitted

their fertilizing granules. The insect, satisfied, seeks to get out; but the needle-like hairs, which from their direction allowed it to enter, absolutely prevent its exit: it is a prisoner. But there is plenty of nectar, so that it has both barracks and rations. Meanwhile, the pollen ripens the anthers open, and the minute dust is thrown upon the insect: at the same time, the needle-like hairs wither; and the insect goes out, laden with pollen, to enter another similar flower in which the surface that receives the fertilizing agent is moist and gummy; and in creeping over which the little visitor deposits some of the pollen, by means of which the future seed is made fertile.

Now, the bee does an enormous amount of work in fertilization; but in doing this it also does an immense amount of labour in nectar collecting. And it is a very notable fact that the formation of nectar takes place most freely in hot weather, and is prevented by cold and wet: that is, it is most abundant when the insect is likely to visit. It is from the nectar that the bees derive their honey, and it is equally the food of many insects that do not store it up as the bee does. The amount of sugar contained in the nectar of flowers has been recently investigated; and from Professor A. S. Wilson's analysis, the most remarkable facts are made out. Clover may be selected as an example. He found that one hundred and twenty-five heads of red clover gave sixteen grains of sugar; or one hundred and twenty-five thousand heads gave two and one-fifth pounds of sugar. But each head contains about sixty florets: seven million five hundred thousand distinct flower tubes must be sucked in order to get two and one-fifth pounds of sugar. Roughly speaking, honey contains seventy-five per cent. of sugar; therefore, five million six

hundred thousand flowers, in round numbers; or say, two-and-a-half millions of visits have to be made to obtain one pound of honey. A sufficient evidence of the immense industry of this minute and wonderful animal.

At the Paris Exhibition, M. Mouchot showed in action an arrangement in which the rays of the sun were directly utilized both for cooking food and distilling alcohol. A large concave mirror was directed

towards the sun, and so adjusted that it could follow the motion (apparent) of the sun from East to West. At the focus was a boiler having a very large capacity. On one occasion seventy litres of water were boiled in half an hour; and a pump was maintained in action which raised eighteen litres of water to a height of two metres. This is enough to show that the sun's heat may be utilized in the doing of the world's work, if we can only secure a sufficiently clear atmosphere.

Two Centenary celebrations in the same Century! Who but WesleyanMethodists could have thought of that? There is a refreshing piquancy about the idea: a kind of Hibernian brilliancy of paradox. A Bicentenary,' a Tricentenary 'and so forth indefinitely, is a solemnity known to ecclesiastical and secular history; but to what dictionary, to what encyclopædia, shall we turn for an authorized vocable to designate the second centenary commemoration in the life-time of men and women who neither are nor expect to be centenarians? Semi-centenary will scarcely do: because the first centenary has been celebrated not fifty years ago; and anything suggestive of halfmeasures or half-heartedness would misrepresent the matter utterly; and not suggest the dualism of the epoch. Yet such a paradox is not without a precedent, at least in the vocabulary of Methodism. Why not two Centenary celebrations within fifty years, as well as two Quarterly Collections within six or seven weeks? two 'anniversaries' in the same year: one for the Chapel, the other for the Sunday-School? Necessity is the mother of invention, and gratitude is the inspirer of genius. Love and lack, when they come together, are

fertile in resources, daring in expedient: A deed without a name,' is not necessarily a weird perpetration. The meek retort of the stripling hero of Ephes-dammim, 'Is there not a cause?' is ample vindication of what to commonplace courage and average devotion seems absurdly adventurous and braggartly foolhardy. The cause, like the commemoration, is twofold: first, God's great mercies in the recent past; second, the pressing pecuniary exigencies of His Work. First, Is

there not a cause for thankfulness? thankfulness enthusiastic, practical, self-sacrificing? The Fund in process of formation is The Thanksgiving Fund in other words, a fund of thankofferings. It is commemorative of an epochal development: a consummation, which was in reality a crisis. And if it were not, at the time, recognized as critical-by reason of the quietness and gracious naturalness with which it was passed through, so that its perils are fully realized only in the retrospect: this is the very ground for gratitude: that so great a readjustment should have been accomplished without convulsion, paroxysm, spasm.

It will be admitted that since the Conferences of 1795, 1796 and 1797, no three successive Conferences have

been so important, so historical, as constitutive and inaugurating assemblies, as those of 1876, 1877 and 1878, in Nottingham, Bristol and Bradford. And what a contrast? In the former case shocks and heavings, detonation and disruption, like the prophetic earthquake when the mount of Olives shall cleave in the midst thereof,' leaving'a very great valley' between the rival peaks; in the latter, calmness, consolidation and drawing and binding together. The new arrangement did not even take the form or bear the aspect of concession it was a cordial convention, the joint workmanship of Ministers and laity. If it was not a later Plan of Pacification, that was because there was no passion to pacify, no agitation to allay. There were not, as in the earlier instance, two councils to be reconciled, two camps to come to terms; and the result was-not a treaty, but a covenant. Yes, it is the manner in which the evolution was effected that is matter of such grateful wonder. The thing itself was inevitable sooner or later: question of chronology; but that it should have been brought to pass with such placidity and moderation can only be accounted for by the pervading and controlling grace of God. The safe and amicable settlement of so grave a question is, surely, an ample justification, a worthy occasion for the erection of a lofty, solid, broad-based Stone of Help, which may be at the same time monumental and serviceable at once a trophy, a landmark and a trysting-place.

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And is there not a cause' also in the exigencies of the Work of God? On this it is superfluous to dwell in detail; since we could do little else than quote documents and speeches already familiar to our readers, especially the lucid and persuasive Statement and Appeal: an admirable opening of an extraordinary or supplemental Budget; the two letters of

Mr. Arthur, and the luminous and convincing speeches of the President and Dr. Punshon. Would that our space would admit of giving all in full their excellence throughout baffles selection. The hampering, harassing, and if not soon disposed of, the strangling debts of our various departments, must be effectually dealt with. The bluff battle-speech of the unwordy corporal to his company is rhetoric enough for the emergency : 'There's the enemy; and if you don't kill them, they'll kill you.' This is the alternative; that the dilemma. Or like the serpents that slew Laocoon and his sons, they will coil about, first the sinews, and then the throat of Methodist enterprise and self-sustentation, till they first constrict, and then crush its energies, and at last choke its vitality. It is matter of devout thankfulness that four most important Connexional departments-the Book-Room, the Chapel Fund, the Children's Fund and the Worn-out Ministers' and Ministers' Widows' Fund-in former times heavily burdened with debt, have now no need to stand forth as claimants for a share in the Thanksgiving Fund; the first, indeed, rendering effective supplies to other branches of the Work of God. But the debts on our other great Funds have become menacing embarrassments, and must forthwith be cleared out of the way by some resolute Connexional effort.

And extension must be combined with relief, as experience as much as exigency teaches. The two great arms of the aggressive service: Missions and Education, must be both lengthened and strengthened, as well as freed from shackling liabilities. As to both Home and Foreign Missions, it behoves Methodism to take up a more commanding position, to present a bolder front, and to carry out its evangelistic commission, with heaven-derived impetus and a holy audacity greater than ever. Never did the commissioning Spirit cry with

a

more urgent and animating emphasis: 'O Zion, that bringest good tidings, get thee up into the high mountain; O Jerusalem, that bringest good tidings,lift up thy voice with strength; lift it up, be not afraid; say unto the cities of Judah, Behold your God.'

And it must not be forgotten that our evangelistic work is now not less defensive than aggressive. At every 'open door' which the Head of the Church has set before us, 'there are many adversaries.' The President

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has opportunely and happily reminded us that the High Church movement was, in its rise, contemporaneous with the Centenary of Methodism. The zeal of our fathers 'provoked very many.' It is but a reasonable, and not ungenial, reciprocity, as well as a fair and honest rivalry, that we, in turn, should emulate the zeal, activity, indefatigability and liberality which was kindled at our own hearth. The High Church party is bidding heavily against us for the poor and for the young, both in town and country; in the great centres of industry, and in the sparsely peopled rural districts. That Christ is preached,' we 'rejoice, yea, and will rejoice." But that the Church is preached, as an intermediary between the soul and its Saviour, we will not silently endure. To the successors of the first Christian opponents of a direct salvation, the preachers of salvation by ceremony and corporate and corporeal officiations, we will not 'give place by subjection,' or by negligence, 'no, not for an hour; that the truth of the Gospel may continue with' the people of these lands. But there is another foe more dangerous than even Ritualism, because more accordant with the tendency of the times: baptized and ordained scepticism; an 'abomination that maketh desolate,' 'standing where it ought not.' Hence the necessity of preoccupying the juvenile and the popular mind with a living faith in Christ and in His glorious Gospel;

and in order to this, a renewed crusade against every form of error and evil in the land.

The Providential calls to enthusiastic effort on behalf of Foreign Missions are equally imperative and heart-touching. Far off and near, the nations crave the Gospel, from France to Equatorial Africa, and on to China and Japan, the spiritual necessities of the unsaved peoples are most appealing and imploring.

It may serve to mark the wondrous growth of Methodism in material strength to compare the appeals made by the Conferences of 1799, 1800 and 1801' to the Methodist Societies and Congregations, on the present distressed state of our Finances,' for a 'General Collection.' The Connexional debt amounted to nearly two thousand pounds; moderately stated as 'above nineteen hundred pounds.' The occasion was then, as now, 'the rapid increase of the work of God.' The manly simplicity and pathos of the Address is very touching, as the following, not now untimely, extracts will show :

'In order to support the immense labours which so great and extensive a work requires, it was necessary to engage a large

additional number of Preachers.... And the real necessity of the case was accompanied with the loud calls of the people in various parts for additional labourers.....Our endeavours to accommodate the Societies with the Preachers they have desired, have been in many instances the cause of long removes and great expenses...None upon earth, we sincerely believe, give so largely as you, in proportion to your abilities, for the cause of religion: and while the revival continues (and we trust it will continue till the commencement of the great millennium), we must expect occasional difficulties in our temporal concerns. It is, we doubt not, for our good....It affords our brethren one of the best means of evidencing their love to God, by delivering not only His Ministers, but His work itself, in some sense, from those difficulties which He, in infinite wisdom, suffers it to be brought into, in the course of human events.

'Need we enlarge? Poor as we are, and poor as it is best for us to be, you feel for our honour, and for that of the