others: of which fluid when our bodics are totally deprived, they are said to be frozen; when they have a proper quantity, they are in health, and fit to perform all their functions; it is then called natural heat: when too much, it is called fever; and when forced into the body in too great a quantity from without, it gives pain by separating and des troying the flesh, and is then called burning; and th Quid so entering and acting is called fire.

While organized bodies, animal or vegetable, ar augmenting in growth, or are supplying their con tinual waste, is not this done by attracting and con solidating this fluid called fire, so as to form of it a part of their substance? and it is not a separation of the parts of such substance, which, dissolving its solid state, sets that subtle fluic at liberty, when it again makes its appearance as fire?

For the power of a man relative to matter seems limited to the dividing it, or mixing the various kinda of it, or changing its form and appearance by differ ing compositions of it; but does not extend to the making or creating of new matter, or annihilating the old: thus, if fire be an original element, or kind of matter, its quantity is fixed and permanent in the world. We cannot destroy any part of it, or make addition to it; we can only separate it from that which confines it, and so set it at liberty, as when we put wood in a situation to be burnt; or transfer it from one solid to another, as when we make lime by burning stone, a part of the fire dislodged from the wood being left in the stone. May not this fluid, when at liberty, be capable of penetrating and enter ing into all bodies, organized or not; quitting easily n totally those not organized; and quitting easily in art those which are; the part assumed and fixe remaining till the body is dissolved?

Is it not this fluid which keeps asunder the particles of air, permitting them to approach, or separating them more, in proportion as its quantity is dimin ished or augmented? Is it not the greater gravity of the] particles of air, which forces the particles of

this fluid to mount with the matters to which it i attached, as smoke or vapour?

Does it not seem to have a great effinity with water, since it will quit a solid to unite with that fluid, and go off with it in vapour, leaving the solid cold to the touch, and the degree measurable by the thermometer?

The vapour rises attached to this fluid; but af a certain height they separate, and the vapour de cends in rain, retaining but little of it, in snow ( hail less. What becomes of that fluid? Does it riso above our atmosphere, and mix equally with the universal mass of the same kind? Or does a spherical stratum of it, denser, or less mixed with air, at tracted by this globe, and repelled or pushed up only to a certain height from its surface, by the greater weight of air remain there surrounding the globe, and proceeding with it round the sun?

In such case, as there may be a continuity or com munication of this fluid through the air quite down to the earth, is it not by the vibrations given to it by the sun that light appears to us; and may it not be, that every one of the infinitely sinall vibrations, striking common matter with a certain force,enter its substance, are held there by attraction, and augmented by suc ceeding vibrations, till the matter has received as much as their force can drive into it?

Is it not thus that the surface of this globe is continually heated by such repeated vibrations in the day, and cooled by the escape of that heat when those vibrations are discontinued in the night, or intercepted and reflected by clouds?

Is it not thus that fire is amassed, and makes the greatest part of the substance of combustible bodies? Perhaps when this globe was first formed, and its original particles took their place at certain distances from the centre, in proportion to their greater or less gravity, the fluid fire, attracted towards that centre, might in great part be obliged, as lightest, to take place above the rest, and thus form the sphere of fire above supposed, which would afterwards be continu. ally diminishing by the substance it afforded to organ

ized bodies; and the quantity restored to it again by the burning or other separating of the parts of those bodies.

Is not the natural heat of animals thus produced, by separating in digestion the parts of food, and setting their fire at liberty?

Is it not this sphere of fire which kindles the wandering globes that sometimes pass through it in ou Course round the sun, have their surface kindled by t, and burst when their included air is greatly rarí fed by the heat on the burning surfaces