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to the calorific gases—imperceptible to us from their minuteness, just as moisture adheres to these gases in soap bubblesand are transported by them to the area where clouds are suispended. Here the combustible and fluescent particles are arrested, and the gases, relieved of the heavier portions of matter, now elevate the remainder, still adhering to them to an extreme point in space, a point beyond which no earthly matter can pass. It is at this point that gaseous influence arrives at its height, here it encounters other gaseous compounds that have reached the same point from another source—the sun-and the contact causes a disruption of their parts; they are decomposed, and the new compound from this union acquires gravity, and is precipitated to the earth with entirely new qualities and character. Levity effects its object through the means of heat and gas.
The first impulse of cold, when set free from its latent state, is to force its particles against the surface of all bodies as closely as the density of the bodies will admit. In doing this, it causes the particles of solids to cohere and unite together by reason of the smaller spaces which the calorific gases must occupy within the interstices of these particles and in the solid mass. This compression produces cohesion, and the force continues until matter approximates to the closest union of which its nature is susceptible-to the utter exclusion of the calorific gases. Gravity operates by means of the condensing power of cold, and a repellent power equivalent to pressure.
Heat and gas, cold and weight, or pressure, are the prime movers of material particles. Gravity impels its agents, cold and weight; and levity impels its agents, which are heat and gases. The former acts on the surface of solids, and the latter on the interstices of these solids.
The calorific gases have the capacity of transferring the loose, abraded particles of solid matter, as well as heat, to other bodies, and of diffusing this matter throughout, according to the density of the body. Heat itself is not elastic, nor does it possess the quality of lightness, but its precise nature can never be known, because it is only made perceptible by means of gaseous compounds.
The most unacceptable part of this theory will be, that we have added the power of cold to a principle which hitherto has only signified weight or gravity. It is the novelty of the thing, however, and not any unfitness in the term itself
, which will cause the objection. By allowing the existence of a power like cold, a great point is gained, which is simplicity. Cold is to gravity what heat is to levity.
The influence that levity exercises over so great a power as the earth is apportioned to the smallest globule of stone. The particles of a drop of water-by centrifugal repulsion, or, in VOL. XXII.
other words, by the power of calorific gases--can be easily forced from the centre of that drop, as an iminense accumulation of water, by the same power, can be forced from the centre of the earth.
So of equal magnitude is gravity, if, as Newton suggested, it can press all the particles of matter from a certain point in space to the centre of the earth, it can regulate its action to the smallest particle. Accordingly it compresses all the atoms of bodies to the centre which pressure gives to these bodies, whether great or small, as near an approach to roundness as their density will admit. All the particles of loose, disjointed matter, not homogeneous, but as dissimilar as possible, will be forced by the same impulse, either in loose atoms or in concrete masses, to a great body like the earth, and in atoms, to the smallest globule of water—these atoms being proportionate to the size of the globule.
Let any one examine the movements of a drop of water as it lies on a cabbage leaf. The least agitation of the leaf shows that the drop of water does not only turn on its own axis, but that it rolls over the surface of the leaf without losing its globular form. While the frigoric principle has power, the drop retains its round form; but when the calorific gases are excited to action by the heat which is elicited by the sun's rays, they overcome the influence of the other power, cold, and the drop loses its form.
On close examination, it will be seen that no point of the surface of the globule of water touches the leaf; it moves as free in space as our earth does. All the particles of the smallest drop of water are as much impelled to the centre of its own small body as the solid mass of particles of the earth are forced to its own centre.
Even to such minute spheres as drops of water, atoms of dust will adhere closely, or gravitate, just as a stone would fall or gravitate to every point of the earth's surface and remain there. If a few particles of dust, such as detach themselves from down or straw or other equally light materials, fall gently from our fingers over a drop of water as it lies on a cabbage leaf, the dust will alight on the surface and lie there. If our vision were suited to the inspection of so minute a phenomenon, it would be seen that very fine particles of dust-when in the act of falling---inclining a little from the centre of gravity of this drop, would be impelled from the straight line which would take them to the earth, and be forced to the surface of the smaller body to which they were nearest. A small fraction of straw will adhere to the drop, for it is extremely light, having the interstices filled with elastic gas.
We have observed that the two primary powers, levity and
gravity, do not of themselves possess the properties of heat and cold, but that they excite heat and cold to action, and that these two agents, when rendered perceptible, owe their circulation to other powers subordinate to them; the gases accompany heat, and a principle, the name of which, as we observed, is still unknown, obeying the impulse of cold.
But if gases act so conspicuous a part, and are thus subservient to a higher power, their services are not available to any definite purpose, unless they have a fluid medium in which to move. All perceptible matter, such as is necessary to build up, repair, and decompose organized and disjointed bodies, can only be usefully distributed by passing through a fluid medium. Gases, therefore, act as definite points when traversing a fluid or moist medium.
It is one of the primary laws of nature, that matter of all kinds should follow in the wake of gaseous movements; thus preventing the utter annihilation of bodies which would take place in time if one power were uncontrolled. The fresh particles of matter—latent though it may be considered by our imperfect conceptions—which always accompany or adhere to the gases, are deposited by them wherever friction occurs; for during this friction some combinations of matter are destroyed. The particles of matter, whether latent or perceptible at the time, are shattered by the collision and are often driven into new compounds, sometimes occupying a less space than they did before, so that it becomes necessary for fresh matter to supply their place.
If a switch or stick be quickly moved through the air, either in a circular or straight line, the disturbance among the particles of matter is imperceptible to us; we merely hear a sound and feel a wind. By this it is known that some commotion has taken place among the particles of air. The sound proceeds from the disruption of gaseous matter, and to the sudden collision of their particles. That this sound is not heard when the stick moves gently and slowly, is in consequence of the ease with which the separated particles can meet again. They have time, as it were, to unite without much loss or disturbance; if violently driven from their equable motion, fresh gaseous compounds rush to the spot and deposit fresh matter.
The same circumstances which require the aid of a new supply of matter in space, require the like assistance when perceptible, tangible, solid bodies come violently in contact. Every revolution of a steel point which is rapidly turning on an iron plate, forces the matter which it touches, and separates it into new combinations. We do not allude particularly to the flakes or large pieces of steel which fly off by means of this friction, but the minute particles reduced to an impalpable powder. As
gases have the capacity to receive in union, or on their surface, decomposed and abraded particles of matter, they must be surcharged with them at this point of friction, and as this rapid friction increases the volume and quantity of gaseous compound, heat is set free in proportion. So long, therefore, as the steel point revolves, heat will be generated at this spot.
If the steel point be made to revolve under water, heat is still set free, and the increased temperature of the fluid shows its presence. The heat which would attach itself to the particles of iron when in a dry state, now diffuses itself through the water; for gases move with a more definite purpose and more slowly when in a dense fluid, like water, than when at liberty in the atmosphere. The temperature of the water is raised, but the air around the steel point is not heated to the extent of the water at the same distance from the centre of friction.
Gases therefore require a fluid menstruum, or a humid, moist atmosphere, for the purpose of carrying on the operations of nature. The principle of growth and decay relies on the gases, for they alone carry or propel all latent and perceptible matter for the building up and destroying of all organic and inorganic substances. They are endowed with a perceptible motion, which can never cease so long as planets revolve. It is the great privilege of man to abstract and appropriate a part of this active gaseous power; he can either accelerate or retard its motions.
It is no proof to say that heat, cold, and light, cannot be composed of material particles because they can be created at pleasure, ad infinitum, without perceiving whence they come. All atmospheric space is filled with partially decomposed matter in perpetual circulation, both latent and free. If this were not the case how could we account for the clouds? We see them in the mass as they are suspended around the earth; but excepting in smoke, vapours and dust—all of which form but a very small portion of them—the ascending particles that make up the vast whole are ne seen by us. Clouds are not formed altogether of vapoury or bituminous particles; the gases are for ever ascending and parting with the matter with which they are charged. They take up all the particles which the vital principle has rejected, and those very particles are projecting into space-into the region of the clouds—where they are to undergo a change to assist either in the processes of decay or growth. As long, therefore, as matter can be acted upon by friction, so long will decomposition proceed, and so long will elasticity and heat be rendered perceptible. As long as gravitation acts, so long will heaviness and cold be perceptible.
By abstracting the calorific gases, gravity has complete power over a body, as in the case of the guinea and feather in an
exhausted receiver, and in the sheet of paper. If a half sheet or strip of letter paper be held to the fire, or over a lamp, until all moisture have disappeared, and be then laid on a smooth table, rubbing the paper quickly over with caoutchouc, the calorific gases will leave the paper and enter the pores of the caoutchouc. We have observed throughout that gases do not attach themselves to substances, or move equably through them, unless moisture be present. The paper, thus deprived of moisture, is now under the complete control of another powergravity—which power forces all bodies to a close union with their own particles and to the surface of other bodies. It will be perceived that the paper has acquired greater weight, although nothing apparently has been added. On lifting it up it adheres to the table, requiring a slight effort to remove it. By throwing it thus charged with the principle of gravity against the wall, it will adhere and remain suspended until the pores of the paper are again filled with the gaseous fluids of the surrounding atmosphere.
Why should the paper adhere to the table and the wall, when the calorific
and moisture have been abstracted? Not, surely, because the table and wall attract it, or because it is charged with the electric fluid, which are the popular modes of accounting for the phenomenon. The electric fluid is nothing more than a peculiar development and modification of heat—nothing more than the calorific gases powerfully charged with the latent particles of ignitible matter. Instead of adding weight to the paper it should render it less heavy. The mere matter of lightning is not heavy—it is the propelling force which makes this matter enter a body and tear it asunder; but when the electric fluid is circulating equably, it has the property of rendering any thing more elastic and buoyant. The paper is forced to the surface of a body in consequence of the power which gravity has over a solid when that solid is deprived of the calorific gases and moisture.
If the paper be again heated and rubbed with caoutchouc, and quickly applied to the brass knob of a small electrometer, the gravitating principle will not only force the paper to the bras knob, but will project the two cork balls forward, which balls are at least six inches from the knob. The cork or pith balls are filled with the elastic gases, which, not being in sufficient' quantity to resist the pressure thus suddenly thrown against them, are unable to prevent the balls from moving out of their place. If a book, or any other object, be placed within an inch of the balls as they hang suspended from the brass wire, they will be driven against the book the moment the charged paper strikes the brass knob at the other end. But if the heat of a lamp or candle be placed about an inch from the